Tuesday, December 27, 2011

How Bacteria Fight Fluoride in Toothpaste and in Nature

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Yale researchers have uncovered the molecular tricks used by bacteria to fight the effects of fluoride, which is commonly used in toothpaste and mouthwash to combat tooth decay.

In the Dec. 22 online issue of the journal Science Express, the researchers report that sections of RNA messages called riboswitches -- which control the expression of genes -- detect the build-up of fluoride and activate the defenses of bacteria, including those that contribute to tooth decay.

"These riboswitches are detectors made specifically to see fluoride," said Ronald Breaker, the Henry Ford II Professor and chair of the Department of Molecular, Cellular and Developmental Biology and senior author of the study.

Fluoride in over-the-counter and prescription toothpastes is widely credited with the large reduction in dental cavities seen since these products were made available beginning in the 1950s. This effect is largely caused by fluoride bonding to the enamel of our teeth, which hardens them against the acids produced by bacteria in our mouths. However, it has been known for many decades that fluoride at high concentrations also is toxic to bacteria, causing some researchers to propose that this antibacterial activity also may help prevent cavities.

The riboswitches work to counteract fluoride's effect on bacteria. "If fluoride builds up to toxic levels in the cell, a fluoride riboswitch grabs the fluoride and then turns on genes that can overcome its effects," said Breaker.

Since both fluoride and some RNA sensor molecules are negatively charged, they should not be able to bind, he notes.

"We were stunned when we uncovered fluoride-sensing riboswitches" said Breaker. "Scientists would argue that RNA is the worst molecule to use as a sensor for fluoride, and yet we have found more than 2000 of these strange RNAs in many organisms."

By tracking fluoride riboswitches in numerous species, the research team concluded that these RNAs are ancient -- meaning many organisms have had to overcome toxic levels of fluoride throughout their history. Organisms from at least two branches of the tree of life are using fluoride riboswitches, and the proteins used to combat fluoride toxicity are present in many species from all three branches.

"Cells have had to contend with fluoride toxicity for billions of years, and so they have evolved precise sensors and defense mechanisms to do battle with this ion," said Breaker, who is also an investigator with the Howard Hughes Medical Institute. Now that these sensors and defense mechanisms are known, Breaker said, it may be possible to manipulate these mechanisms and make fluoride even more toxic to bacteria. Fluoride riboswitches and proteins common in bacteria are lacking in humans, and so these fluoride defense systems could be targeted by drugs. For example, the Yale team discovered protein channels that flush fluoride out of cells. Blocking these channels with another molecule would cause fluoride to accumulate in bacteria, making it more effective as a cavity fighter.

Fluoride is the 13th most common element in Earth's crust, and it is naturally present in high concentrations throughout the United States and elsewhere. Its use in toothpaste and its addition to city water supplies across the United States sparked a controversy 60 years ago, and the dispute continues to this day. In the United Kingdom, and in other European Union countries, fluoride is used to a much lesser extent due to fierce public opposition.

The new findings from Yale only reveal how microbes overcome fluoride toxicity. The means by which humans contend with high fluoride levels remains unknown, Breaker notes. He adds that the use of fluoride has had clear benefits for dental health and that these new findings do not indicate that fluoride is unsafe as currently used.

Saturday, December 17, 2011

Addition of Mannitol Increases Effectiveness of Dental Nerve Block Anesthesia

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Allowing a patient to be comfortable and pain-free during surgical and restorative dental procedures is an essential part of the process. The most commonly used local anesthetic injection for lower teeth is the inferior alveolar nerve (IAN) block. However, failure rates ranging from 10 to 39 percent have been reported.

The current issue of the journal Anesthesia Progress presents a study testing the efficacy of adding a solution of mannitol to the anesthetic typically used in IAN blocks. Forty adult subjects participated in the study, receiving an IAN block at each of three separate appointments at least one week apart.

The study compared the effectiveness of the standard anesthetic, lidocaine with epinephrine, to the effectiveness of two different volumes of lidocaine with epinephrine plus 0.5 M mannitol. Mannitol is a sugar alcohol that occurs naturally in fruits and vegetables. It is rapidly excreted by the kidneys.

Though its impact is short-lived, mannitol has the positive effect of opening the perineurial membrane. It is believed that, in cases of IAN block failure, the perineurial barrier around the nerve does not allow complete diffusion of the anesthetic into the nerve trunk. The addition of mannitol apparently allows enhanced permeability, increasing the success of an IAN block when administered concurrently.

After injections of the IAN block solutions, subjects’ pain levels were measured by an electric pulp test of their mandibular teeth at 4-minute intervals for 60 minutes. The study concluded that the addition of mannitol to lidocaine with epinephrine significantly increased the effectiveness of the anesthesia.

About Anesthesia Progress

Anesthesia Progress is the official publication of the American Dental Society of Anesthesiology (ADSA). The quarterly journal is dedicated to providing a better understanding of the advances being made in the science of pain and anxiety control in dentistry. The journal invites submissions of review articles, reports on clinical techniques, case reports, and conference summaries. To learn more about the ADSA, visit:

Oral Bacteria Enables Breaking Bond On Blood Vessels to Allow Invaders in

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A common oral bacteria, Fusobacterium nucleatum, acts like a key to open a door in human blood vessels and leads the way for it and other bacteria like Escherichia coli to invade the body through the blood and make people sick, according to dental researchers at Case Western Reserve University.

Yiping Han, professor of periodontics at the Case Western Reserve School of Dental Medicine, made the discovery in her continued work with the Fusobacterium nucleatum bacterium, one of the most prevalent of the more than 700 bacteria in the mouth.

She found the gram-negative anaerobe has a novel adhesin or bonding agent she's named FadA that triggers a cascade of signals that break the junctures in an interlocking sheath of endothelial cells on blood vessel's surface just enough to allow F. nucleatum and other bacteria into the blood.

A description of bond-breaking process was described in the Molecular Microbiology article, "Fusobacterium nucleatum adhesin FadA binds vascular endothelial cadherin and alters endothelial integrity."

The microbiologist at the dental school has studied the oral bacteria over the past decade and was the first to find direct evidence that linked it to preterm labor and fetal death. But its presence is found in other infections and abscesses in the brain, lungs, liver, spleen and joints.

After finding and genetically matching the oral bacteria in the fetal death, she began to unravel the mystery of how an oral bacterium can be found throughout the body and jumps the blood-brain and placental barriers that usually block disease-causing agents.

Through years of lab work, her research led to the vascular endothelial (VE)-cadherin, cell-cell junctures that link the endothelial vascular cells together on the blood vessels.

These junctures are like a hook and loop connection, but for some unknown reason when F. nucleatum invades the body through breaks in the mucous membranes of the mouth, due to injuries or periodontal disease, this particular bacterium triggers a cascade of signals that causes the hook to recede back into the endothelial cell. The oral bacterium leads the way with any other harmful invaders following along.

This "deceding" was observed by confocal microscopy when Han used cells from human umbilical cord. The researchers introduced F. nucleatum and demonstrated the VE-cadherins break on bonds on the endothelial cells and creating enough space in the endothelium for the invaders to move in.

Lab tests included introducing F. nucleatum with and without other bacteria. When E. coli alone was introduced, the bond did not break. But when F. nucleatum was introduced first, the bond broke, and the E. coli bacteria were able to move through the otherwise intact cell layers.

"This cascade knocks out the guard on duty and allows the bacteria to enter the blood and travel like a bus loaded with riders throughout the system. Whenever the F. nucleatum wants to get off the bus at the liver, brain, spleen, or another place, it does," Han said.

When it disembarks from its ride through the blood, it begins to colonize. The colony of bacteria induces an inflammatory reaction that has a range of consequences from necrosis of tissue to fetal death.

Wednesday, December 14, 2011

Oral Surgery Protocol to Control Bleeding for Heart Patients Shows Positive Results

Cardiac patients that take anticoagulant medications and need a tooth extraction face an increased risk of bleeding that must be addressed by the treating clinician. Therefore, a protocol for heart patients is needed that will avoid significant bleeding after dental extractions without suspending anticoagulant therapy.

A study reported in the current issue of the Journal of Oral Implantology evaluated the use of leukocyte- and platelet-rich fibrin biomaterial. This material is commonly used in dentistry to improve healing and tissue regeneration. It was tested as a safe filling and hemostatic material after dental extractions in 50 heart patients undergoing oral anticoagulant therapy.

These heart patients had mechanical valve substitutions, and then were placed on anticoagulant oral therapy with warfarin. It is not recommended that the anticoagulant be suspended and replaced with heparin before a minor surgery, although this substitution may control the risk of postoperative bleeding.

One method of controlling bleeding without suspending the anticoagulant is the use of platelet-rich plasma gel placed in postextraction tooth sockets. Although this protocol has been successful, there are barriers to its daily use. The platelet concentrates are expensive and take a long time to prepare.

Platelet-rich fibrin offers an alternative biomaterial that is simple and inexpensive to prepare. Blood is collected in tubes without anticoagulant and centrifuged. It divides into three layers, creating a strong platelet-rich fibrin clot in the middle layer. Platelet-rich fibrin has proved useful in daily dental practice as filling material for regeneration in order to place implants.

In this study, 50 heart patients following an anticoagulant therapy were treated with leukocyte- and platelet-rich fibrin clots placed into postextraction sockets. Complications of bleeding were reported in only two of these patients, and 10 had mild bleeding. All complications were resolved within a few hours after the oral surgery.

Additionally, the study reported no painful events, quick healing of soft tissue, and complete wound closure within one week after oral surgery. Leukocyte- and platelet-rich fibrin offers an excellent option for use in heart patients on an anticoagulant regimen.

Full text of the article, “Prevention of Hemorrhagic Complications After Dental Extractions Into Open Heart Surgery Patients Under Anticoagulant Therapy: The Use of Leukocyte- and Platelet-Rich Fibrin ,” Journal of Oral Implantology, Vol. 37, No. 6, 2011, is available at http://www.joionline.org/ .

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About Journal of Oral Implantology
The Journal of Oral Implantology is the official publication of the American Academy of Implant Dentistry and of the American Academy of Implant Prosthodontics. It is dedicated to providing valuable information to general dentists, oral surgeons, prosthodontists, periodontists, scientists, clinicians, laboratory owners and technicians, manufacturers, and educators. The JOI distinguishes itself as the first and oldest journal in the world devoted exclusively to implant dentistry. For more information about the journal or society, please visit: http://www.aaid-implant.org/index.html

Tuesday, December 6, 2011

Dental X-rays can predict fractures

It is now possible to use dental X-rays to predict who is at risk of fractures, reveals a new study from researchers at the Sahlgrenska Academy reported in the journal Nature Reviews Endocrinology.

In a previous study, researchers from the University of Gothenburg's Sahlgrenska Academy and Region Västra Götaland demonstrated that a sparse bone structure in the trabecular bone in the lower jaw is linked to a greater chance of having previously had fractures in other parts of the body.

X-rays investigates bone structure

The Gothenburg researchers have now taken this a step further with a new study that shows that it is possible to use dental X-rays to investigate the bone structure in the lower jaw, and so predict who is at greater risk of fractures in the future. Published in the journal Bone, the results were also mentioned in both Nature Reviews Endocrinology and the Wall Street Journal.

Linked to risk of fractures


"We've seen that sparse bone structure in the lower jaw in mid-life is directly linked to the risk of fractures in other parts of the body, later in life,"says Lauren Lissner, a researcher at the Institute of Medicine at the Sahlgrenska Academy.

Study started 1968

The study draws on data from the Prospective Population Study of Women in Gothenburg started in 1968. Given that this has now been running for over 40 years, the material is globally unique. The study included 731 women, who have been examined on several occasions since 1968, when they were 38-60 years old. X-ray images of their jaw bone were analysed in 1968 and 1980 and the results related to the incidence of subsequent fractures.

For the first 12 years fractures were self-reported during followup examinations. It is only since the 1980s that it has been possible to use medical registers to identify fractures. A total of 222 fractures were identified during the whole observation period.

One out of five in higher risk


The study shows that the bone structure of the jaw was sparse in around 20% of the women aged 38-54 when the first examination was carried out, and that these women were at significantly greater risk of fractures.

The study also shows that the older the person, the stronger the link between sparse bone structure in the jaw and fractures in other parts of the body.

Applies for both sexes


Although the study was carried out on women, the researchers believe that the link also applies for men.

"Dental X-rays contain lots of information on bone structure," says Grethe Jonasson, the researcher at the Research Centre of the Public Dental Service in Västra Götaland who initiated the fractures study. "By analysing these images, dentists can identify people who are at greater risk of fractures long before the first fracture occurs."

Thursday, November 17, 2011

New Mouthwash Targeting Harmful Bacteria May Render Tooth Decay a Thing of the Past

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A new mouthwash developed by a microbiologist at the UCLA School of Dentistry is highly successful in targeting the harmful Streptococcus mutans bacteria that is the principal cause tooth decay and cavities.

In a recent clinical study, 12 subjects who rinsed just one time with the experimental mouthwash experienced a nearly complete elimination of the S. mutans bacteria over the entire four-day testing period. The findings from the small-scale study are published in the current edition of the international dental journal Caries Research.

Dental caries, commonly known as tooth decay or cavities, is one of the most common and costly infectious diseases in the United States, affecting more than 50 percent of children and the vast majority of adults aged 18 and older. Americans spend more than $70 billion each year on dental services, with the majority of that amount going toward the treatment of dental caries.

This new mouthwash is the product of nearly a decade of research conducted by Wenyuan Shi, chair of the oral biology section at the UCLA School of Dentistry. Shi developed a new antimicrobial technology called STAMP (specifically targeted anti-microbial peptides) with support from Colgate-Palmolive and from C3-Jian Inc., a company he founded around patent rights he developed at UCLA; the patents were exclusively licensed by UCLA to C3-Jian. The mouthwash uses a STAMP known as C16G2.

The human body is home to millions of different bacteria, some of which cause diseases such as dental caries but many of which are vital for optimum health. Most common broad-spectrum antibiotics, like conventional mouthwash, indiscriminately kill both benign and harmful pathogenic organisms and only do so for a 12-hour time period.

The overuse of broad-spectrum antibiotics can seriously disrupt the body's normal ecological balance, rendering humans more susceptible to bacterial, yeast and parasitic infections.

Shi's Sm STAMP C16G2 investigational drug, tested in the clinical study, acts as a sort of "smart bomb," eliminating only the harmful bacteria and remaining effective for an extended period.

Based on the success of this limited clinical trial, C3-Jian Inc. has filed a New Investigational Drug application with the U.S. Food and Drug Administration, which is expected to begin more extensive clinical trials in March 2012. If the FDA ultimately approves Sm STAMP C16G2 for general use, it will be the first such anti-dental caries drug since fluoride was licensed nearly 60 years ago.

"With this new antimicrobial technology, we have the prospect of actually wiping out tooth decay in our lifetime," said Shi, who noted that this work may lay the foundation for developing additional target-specific "smart bomb" antimicrobials to combat other diseases.

"The work conducted by Dr. Shi's laboratory will help transform the concept of targeted antimicrobial therapy into a reality," said Dr. No-Hee Park, dean of the UCLA School of Dentistry. "We are proud that UCLA will become known as the birthplace of this significant treatment innovation."

Wednesday, November 16, 2011

Teeth Crowded in Seniors, as Jaws Shrink

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The size of our jaws decreases with age. This is shown in a unique study from the Faculty of Dentistry at Malmö University that followed a cohort of dentists throughout their adult lives.

The unique study started in 1949. Plaster molds were made of the jaws of dental students, who were then in their twenties. Ten years later the procedure was repeated, and in 1989, forty years after the first molds, a final round was performed. On that occasion the researchers were in touch with 18 of the original 30 participants.

"We found that over these forty years there was less and less room for teeth in the jaw," says Lars Bondemark, professor of orthodontics, who analyzed the material together with his colleague Maria Nilner, professor of clinical bite physiology at the College of Dentistry, Malmö University .

This crowdedness comes from shrinkage of the jaw, primarily the lower jaw, both in length and width. While this is only a matter of a few millimeters, but it is enough to crowd the front teeth.

"We can also eliminate wisdom teeth as the cause, because even people who have no wisdom teeth have crowded front teeth."

How much the jaw shrinks is individual, but for some patients the changes are sufficiently great for them to perceive that something is happening to their bite.

"In that case it's good to know that this is normal," says Lars Bondemark, who maintains that dentists need to take into consideration the continuous shrinking of the jaws when they plan to perform major bite constructions on their patients.

"We're working against nature, and it's hard to construct something that is completely stable."

Why the jaws change throughout life is not known, but the magnitude of the change is probably determined by both hereditary and anatomical factors, including what the patient's bite looks like.

Monday, November 14, 2011

Professional dental cleanings may reduce risk of heart attack, stroke

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Professional tooth scaling was associated with fewer heart attacks and strokes in a study (Abstract 17704) from Taiwan presented at the American Heart Association's Scientific Sessions 2011.

Among more than 100,000 people, those who had their teeth scraped and cleaned (tooth scaling) by a dentist or dental hygienist had a 24 percent lower risk of heart attack and 13 percent lower risk of stroke compared to those who had never had a dental cleaning. The participants were followed for an average of seven years.

Scientists considered tooth scaling frequent if it occurred at least twice or more in two years; occasional tooth scaling was once or less in two years.

The study included more than 51,000 adults who had received at least one full or partial tooth scaling and a similar number of people matched with gender and health conditions who had no tooth scaling. None of the participants had a history of heart attack or stroke at the beginning of the study.

The study didn't adjust for heart attack and stroke risk factors — such as weight, smoking and race — that weren't included in the Taiwan National Health insurance data base, the source of the information used in the analysis.

"Protection from heart disease and stroke was more pronounced in participants who got tooth scaling at least once a year," said Emily (Zu-Yin) Chen, M.D., cardiology fellow at the Veterans General Hospital in Taipei, Taiwan.

Professional tooth scaling appears to reduce inflammation-causing bacterial growth that can lead to heart disease or stroke, she said.

Hsin-Bang Leu M.D., is the study co-author. Author disclosures and funding are on the abstract.

Type of periodontal disease predicts degree of risk for heart attack, stroke, and heart failure

In a separate study (abstract 10576), researchers found that the value of markers for gum disease predict heart attack, congestive heart failure and stroke in different ways and to different degrees.

Anders Holmlund, D.D.S., Ph.D. Centre for Research and Development of the County Council of Gävleborg, Sweden, and senior consultant; Specialized Dentistry, studied 7,999 participants with periodontal disease and found people with:

- Fewer than 21 teeth had a 69 percent increased risk of heart attack compared to those with the most teeth.
- A higher number of deepened periodontal pockets (infection of the gum around the base of the tooth) had a 53 percent increased risk of heart attack compared to those with the fewest pockets.
- The least amount of teeth had a 2.5 increased risk of congestive heart failure compared to those with the most teeth.
- The highest incidence of gum bleeding had a 2.1 increased risk of stroke compared to those with the lowest incidence.

Wednesday, November 9, 2011

Lose the fat and improve the gums

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Case Western Reserve University School of Dental Medicine researchers found the human body is better at fighting gum disease when fat cells, which trigger inflammation, disappear.

Findings come from a pilot study of 31 obese people with gum disease. Half of the group with an average body mass index (BMI) of 39 had gastric bypass surgery and had fat cells from the abdomen removed. That half fared better than a control group of obese people with a BMI of 35 who also were treated for gum disease but did not have the gastric bypass surgery or fat removed.

What intrigued the researchers is that the majority of those who underwent surgery had a drop in their glucose levels after the procedure, a result that bodes well for overweight people predisposed to diabetes and insulin-related problems.

All study participants underwent nonsurgical periodontal treatments of scaling/root planing and oral hygiene instructions for home care. While both groups showed improvement, the surgery group did even better on the measures for periodontal attachment, bleeding, probing depths and plaque levels.

Inflammation that continues to brew in the body can have harmful effects over time, and inflammation from gum disease can erode bone and cause tooth loss. It can also cause breaks in the gums where harmful oral bacteria can enter the blood stream. Such bacteria have been linked to preterm birth, fetal death, heart disease, diabetes and arthritis, said Nabil Bissada, chair of the department of periodontics at Case Western Reserve School of Dental Medicine.

Bissada is the lead author of the study, “Response to periodontal therapy in subjects who had weight loss following bariatric surgery and obese counterparts: a pilot study,” published in the Journal of Periodontology.

This study raises two hypotheses about why the surgery group improved.

The first theory is that excessive fat cells (adipocytes) secrete more cytokines (such as TNF and IL-6), which make insulin more resistant to doing its function.

As a result, more accumulation of sugar in the blood (hyperglycemia) occurs. Losing weight, therefore, makes insulin less resistant and improves the diabetic status. This in turn helps in the response to periodontal treatment.

The other theory relates to the presence of the leptin hormone that regulates appetite. Leptin plays a role in regulating metabolism and has been linked to inflammation by increasing the production of cytokines and the –C-reactive protein, which is also linked to inflammation. Bissada said leptin production was reduced after bariatric surgery and may be one explanation for the better outcomes in the periodontal treatment.

As the researchers look to the further their research, their next step will be to conduct a longitudinal study to support their preliminary findings.

Thursday, October 27, 2011

Healthy mouth bacteria provide ideal conditions for gum disease

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Normal bacteria which live in our mouths provide the catalyst for the development of gum disease, a debilitating condition which leads to painful gums and the loosening of teeth, new research from Queen Mary, University of London has found.

The unexpected finding could pave the way for the development of preventative measures in tackling gum, or periodontal disease*, by manipulating the normal bacteria in the same way that probiotic yoghurt works to protect the intestine.

Researchers at Queen Mary's Blizard Institute, including Medical Research Council Clinical Research Training Fellow Mark Payne, worked with scientists in the US; they published their findings in the journal Cell Host and Microbe today (Oct. 27).

The scientists introduced the oral bacterium Porphyromonas gingivalis to mice living in two different test conditions. The mice with normal bacteria in their mouths developed periodontal bone loss but the mice raised under germ-free conditions, in the absence of any normal bacteria, remained disease-free.

Professor Mike Curtis, Director of the Blizard Institute and co-author on the paper, said when the oral bacterium P. gingivalis was introduced under normal conditions "it stimulated the growth of normal bugs leading to a large increase in the number of those organisms already there".

"P. gingivalis was introduced at very low levels yet it had a major affect on both the immune system and the inflammatory system," he said.

"This oral bacterium only appears in small numbers but appears to have a major influence on the overall ecology. It has a keystone effect in a community – working in the same way that starfish, which have relatively small numbers, control the shell fish communities in the sea.

Professor Curtis said although the findings were encouraging in terms of understanding the way gum disease develops, there was still "some way to go" before there was a similar product on the market for gum disease as a probiotic yoghurt is available for the intestine.

"Now we know that periodontal disease only develops through P. gingivalis interacting with the existing bacteria in our mouths, we need to understand the role played by our normal bacteria in both the development of disease and protection from it," he said.

"This may then provide the means to develop preventative measures for the disease."

Professor Farida Fortune, Dean for Dentistry at Queen Mary said the research was encouraging for people who suffer from gum disease which results in bleeding gums and ultimately loose teeth which cause difficulty in both speaking and eating.

"The public still need to be mindful of the way they look after their teeth and gums," she said.

"People need to pay more attention to their oral hygiene. Their local hygienist, dental therapist and dentist can all assist in teaching them effective cleaning techniques. Just these simple preventative measures, as well as not smoking, will go some way to helping them avoid developing gum disease."

Prenatal exposure to dental amalgam

Background.

Dental amalgams contain approximately 50
percent metallic mercury and emit mercury vapor during the life of
the restoration. Controversy surrounds whether fetal exposure to
mercury vapor resulting from maternal dental amalgam
restorations has neurodevelopmental consequences.

Methods

The authors determined maternal amalgam restoration
status during gestation (prenatal exposure to mercury vapor [Hg0])
retrospectively in 587 mother-child pairs enrolled in the Seychelles
Child Development Study, a prospective longitudinal cohort study of
the effects of prenatal and recent postnatal methylmercury (MeHg)
exposure on neurodevelopment. They examined covariate-adjusted
associations between prenatal maternal amalgam restoration status
and the results of six age-appropriate neurodevelopmental tests
administered at age 66 months. The authors fit the models without
and with adjustment for prenatal and recent postnatal MeHg
exposuhttp://beta.blogger.com/img/blank.gifre metrics.

Results

The mean number of maternal amalgam restorations
present during gestation was 5.1 surfaces (range, 1-22) in the 42.4
percent of mothers who had amalgam restorations. The authors
found no significant adverse associations between the number of
amalgam surfaces present during gestation and any of the six
outcomes, with or without adjustment for prenatal and postnatal
MeHg exposure. Results of analyses with the secondary metric,
prenatal amalgam occlusal point scores, showed an adverse
association in boys only on a letter- and word-identification subtest
of a frequently used test of scholastic achievement, whereas girls
scored better on several other tests with increasing exposure.
Conclusions. This study’s results provide no support for the
hypothesis that prenatal Hg0 exposure arising from maternal dental
amalgam restorations results in neurobehavioral consequences in
the child.

Nearly half of Ontario seniors do not see dentists regularly

Poor oral health tied to chronic disease and worse overall health

TORONTO -- Forty-five per cent of Ontarians 65 years and older did not see a dentist in the last year, increasing their risk of chronic diseases and a reduced quality of life , a new study by researchers at St. Michael's Hospital, Women's College Hospital and the Institute for Clinical and Evaluative Sciences (ICES) shows.

"Poor oral health can contribute to many serious medical conditions and affect a person's ability to chew and digest food properly, leading to inadequate nutrition," explains Dr. Arlene Bierman, principal investigator of the study. "With dental services not covered under our universal health-insurance program and many older adults not visiting dentists regularly , the findings suggest we need to rethink the services we provide to help keep seniors healthy as they age."

According to the researchers, women make up the majority of the older population. They are more likely to have two or more chronic conditions than men, report more disability and chronic pain, and are less likely to be physically active.

"A focus on prevention and health promotion can help older women remain active and independent as they age as too many are physically inactive and do not eat enough fruits and vegetables ," said Dr. Paula Rochon, study investigator and senior scientist at Women's College Research Institute. "Yet, what we do know is that it's never too late to improve quality of life and health for women, regardless of age. In fact, a focus on strategies to improve health in the older population can help prevent chronic disease and its associated complications."

The findings are detailed in a report of the POWER (Project for an Ontario Women's Health Evidence-Based Report) Study — a joint study from St. Michael's Hospital and ICES. The study is the first in the province to provide a comprehensive overview of women's health in relation to income, education, ethnicity and geography. Findings can be used by policymakers and health-care providers to improve access, quality and outcomes of care for Ontario women. The Older Woman's Health report examines quality and outcomes of care among older women and men in home care, long-term care and in the community. The POWER Study was funded by Echo: Improving Women's Health in Ontario, an agency of the Ontario Ministry of Health and Long-Term Care.

"Since women comprise the majority of the older population in Ontario, we need to be paying closer attention to the specific care and service needs of older women," says Pat Campbell, CEO of Echo. "The POWER Study Older Women's Health report provides key suggestions on how we can begin to do this."

Findings of the POWER Study released today include:

- About 60 per cent of older women reported that they were physically inactive compared to 48 per cent of men.
- Less than 45 per cent of older adults took steps to improve their health in the previous 12 months.
- Nearly 67 per cent of women ages 80 and older reported functional limitations and more than 1 in 3 low-income women reported their activities were limited by pain.
-= Nearly 60 per cent of women admitted to the hospital for heart failure are age 80 and older, and 90 per cent are age 65 and older.

Many health-care providers have little training in the care of older adults -- there are only 1 to 5 geriatricians per 100,000 adults 65 and older in some areas of the province.

Women have different patterns of illness and health-care needs compared to men. According to the researchers, previous generations of women had fewer opportunities and financial resources and less education than women today, and are less likely to pay for supportive care and access to health services that are not publicly funded.

Tuesday, October 25, 2011

Modest Improvement in Temporomandibular Disorder–Related Pain Associated With Use of Hard Stabilization Appliances Compared With Use of Nonoccluding A

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Question: Among patients with temporomandibular
disorders (TMDs), does the use of intraoral orthopedic
appliances (IOAs) reduce pain compared with the use of
a placebo control or other treatments for TMD or no
treatment?

Answer:

The results of the study, published in The Journal
of the American Dental Association November Issue,
present limited evidence that use of HSAs leads to
modest improvement in TMD-related pain treatment
efficacy compared with use of NOAs or receiving
no therapy.

There was weak evidence regarding the use of
other types of appliances, including soft stabilization
appliances and anterior bite appliances,in reducing
TMD-related pain compared with notherapy; however,
close monitoring is recommended,as these appliances
might be associated with more adverse events than HSAs.

Many Young Children Off to a Poor Start with Dental Health

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Dental visits are recommended to begin by age 1, but a new poll shows most children age 1-2 have not received appropriate oral health care

Although child health experts recommend that children begin oral health care by age 1 or when their first teeth emerge, a new report from the C.S. Mott Children’s Hospital National Poll on Children’s Health shows that most children ages 1-2 have not yet started seeing a dentist.

In May 2011, the National Poll on Children’s Health asked parents of children ages 1-5 about dental health care for young children. The poll found that only 23% of 1-year-olds had been to the dentist and only 44% of 2-year-olds had been to the dentist.

“Dental problems such as early childhood caries (cavities in the baby teeth) are the leading cause of chronic disease for young children,” says Sarah Clark, M.P.H., Associate Director of the Child Health Evaluation and Research (CHEAR) Unit at the University of Michigan. “Most dental problems can be prevented through good oral health care.”

Parents may not be aware of recommendations for early dental health care and finding a dentist who will see young children – especially those covered by Medicaid – is a long standing problem in some communities. To address these issues, pediatricians and health care providers are now seen as important partners in oral health and are encouraged to discuss oral health during well-child visits.

“Well-child visits are critical to making sure that parents understand their role in preventing dental problems, such as how to clean the child’s baby teeth and the importance of avoiding sugary beverages and bottles in the crib,” says Clark. “Well-child visits are also a key opportunity for a health professional to examine the child’s baby teeth and make sure that children with early signs of decay are strongly encouraged to see a dentist.”

However, when parents of 1-2 year olds were asked about dental health activities that occurred at their child’s most recent well-child visit, less than half of parents said their health care providers talked to them about cleaning the teeth or taking their child to the dentist and 1 in 3 children did not have their teeth examined at all by their health care provider.

“We know that not all children will see a dentist at age 1, but on the other hand, almost all children have well-child visits with a pediatrician or other health care provider,” Clark continues. “The results of this poll indicate that we need to improve the way oral health issues are addressed during well-child visits so that parents fully understand the need for good oral health care.”

Full report

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Monday, October 24, 2011

U.S. State Department Reviewing Ban on Mercury Fillings

Ω

For the first time in history, the U.S. Department of State (DOS) is evaluating international regulations that would ban mercury-containing products including silver/amalgam dental fillings, which contain 50% mercury and are already in the mouths of more than 122 million Americans.


The DOS will present their official position on the use of mercury in amalgam fillings and other medical devices at a stakeholder meeting on Monday, October 24th, from 11:00 AM to 12:30 PM at the DOS headquarters on 2201 C Street, N.W., Washington, D.C.  Members of the International Academy of Oral Medicine and Toxicology (IAOMT) will attend the meeting to encourage a ban on mercury/silver dental amalgam fillings.


The U.S. government's monumental decision about mercury fillings is being made in preparation for the third session of the United Nations Environmental Programme (UNEP) Intergovernmental Negotiating Committee (INC3), scheduled for later this month in Nairobi, Kenya.  The committee was created with the specific purpose of developing a global, legally-binding instrument on mercury due to its significant negative effect on human health and the environment.


Mercury, a potent neurotoxin used in dental amalgam fillings, can damage the brain, kidneys, and nervous system, and is particularly harmful to the fetus and young children. Substantial, peer-reviewed, scientific evidence proving these dangers is documented in IAOMT's Petition for Reconsideration, which was filed with the United States Food and Drug Administration (FDA) in 2009.


The hazards of mercury filings have also been addressed by other international groups.  In 1991, the World Health Organization (WHO) concluded that dental amalgam is "the greatest source of mercury exposure for the general population, exceeding those from food and air."


In the United States, President Obama has recognized the hazards of mercury since 2008, and he emphasized the need to protect children from being exposed to mercury in his September 8, 2011 speech to Congress.


Yet, no actions to defend the American public from the known risks of mercury/silver dental fillings have been taken, although a recent submission by the U.S. to UNEP's Intergovernmental Negotiating Committee supports "further consideration of dental amalgam by the INC...with the goal of potential or gradual phasedown of dental amalgam and ongoing research for affordable, viable alternatives."


Such a position is unacceptable to Dr. David Kennedy, past president of IAOMT, who explains, "Using the excuse of alternative materials to further delay protecting the public is illogical because safe alternatives to mercury fillings have already been used for more than 20 years."


Leo Cashman, executive director and volunteer for the non-profit, consumer advocacy group Dental Amalgam Mercury Solutions (DAMS), agrees: "Dental amalgam is not viable when the costs of mercury poisoning to the individual, to families, and to the healthcare industry are considered."


"If we accept the current treaty language of UNEP, WHO, and the U.S. State Department, as well as their associated health declarations that I completely disagree with, the treaty will be about an 'infinite phase down' which won't even begin phasing down mercury/silver amalgam dental filling placement until 2020 the soonest, but more likely 2030, with requested exemptions by the FDI", says Dr. David Simone, who will be representing IAOMT at the DOS meeting. He reiterates, "The way it stands now, the UNEP Mercury Instrument is designed to keep placing mercury amalgams in all populations for another 20 years at least."


Freya Koss, President of the PA Coalition for Mercury-Free Dentistry, was diagnosed with myasthenia gravis after having an old mercury amalgam filling drilled out and replaced with a new one, and she will be at the meeting to insure that the DOS keeps mercury fillings in a proposed ban portion of the INC treaty.


Marie Flowers, President of Dental Amalgam Mercury Solutions (DAMS), experienced neurological symptoms following the removal of a mercury amalgam filling and will likewise be at the DOS meeting on Monday.  Flowers has commented, "The U.S. lags behind countries such as Sweden, who initiated a mercury phase out in 1987, followed by Denmark and Norway, who banned dental mercury amalgam in 2009.


Nashville's Fox 17 anchor Stacy Case told her personal story of mercury poisoning to the FDA at a recent Town Meeting in San Francisco: "I had four amalgams unsafely removed and replaced with four shiny mercury fillings, and I got out of bed one day and couldn't walk."  However, Case recovered from her diagnosis of multiple sclerosis after her fillings were safely removed.  Her message to the U.S. government is clear: "Use your power and position for good.  Please right this wrong!"


IAOMT and other groups are strongly urging the DOS to support the position of the U.S. Government as stated in February 2009 by Nancy Sutley, Chair of the White House Council on Environmental Quality, who announced, "Mercury poses a serious threat to public health in communities around the world...The United States will play a leading role in working with other nations to craft a global, legally binding agreement that will prevent the spread of mercury into the environment and improve the health of workers, pregnant women, and children throughout the world."


Monday's DOS meeting about the U.S. position on the INC treaty will set the international stage for the future of mercury in dentistry, which many hope will be the end of drilling a potent neurotoxin into the mouths of an unsuspecting international public.  

Friday, October 21, 2011

Tissue Graft Prevents Gum Recession After Tooth Implant

When a tooth is replaced with an implant, receding of the gums can become a concern. This leaves areas of root exposed and can be painful for the patient. While a single tooth replacement performed as an immediate, one-step process is an accepted treatment, gum recession occurs more often with this method of implant.

The current issue of the Journal of Oral Implantology reports on a case series of 10 patients who received a single immediate tooth replacement in conjunction with subepithelial connective tissue graft. The tissue graft has proven successful in making gingival, or gum, tissue more resistant to recession.

In the immediate tooth replacement procedure, a failing tooth is removed and an implant is immediately placed into the socket. For the tissue graft, tissue is harvested from the palate using a single incision. The graft material is inserted into a prepared space between the labial bony plate and the gingiva of the extraction site. The graft preserves soft tissue levels, making the gum less likely to recede.

Marginal bone level is another way to gauge the success of an implant. A more recent suggestion, which this study evaluates, is that this bone level can be influenced by the way the implant and abutment connect. “Platform switching”—which refers to the size discrepancy between these two components—can be beneficial in maintaining the marginal bone level.

In this study, patients were evaluated before surgery, at the time of tooth replacement, and at three, six, and twelve months after surgery. One implant failed early in the process, but at one year the remaining nine patients showed good integration of tissue and tooth with minimal loss of marginal bone level or facial gingival level. The authors concluded that with proper implant position and the placement of graft material, a favorable success rate can be achieved.

Full text of the article: “Immediate Single Tooth Replacement With Subepithelial Connective Tissue Graft Using Platform Switching Implants: A Case Series

About Journal of Oral Implantology
The Journal of Oral Implantology is the official publication of the American Academy of Implant Dentistry and of the American Academy of Implant Prosthodontics. It is dedicated to providing valuable information to general dentists, oral surgeons, prosthodontists, periodontists, scientists, clinicians, laboratory owners and technicians, manufacturers, and educators. The JOI distinguishes itself as the first and oldest journal in the world devoted exclusively to implant dentistry. For more information about the journal or society, please visit: http://www.aaid-implant.org/index.html


Friday, October 14, 2011

Certain Mouth Bacteria Signal Pancreatic Cancer

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Particular types of mouth bacteria, some of which are found in gum disease, are associated with the development of pancreatic cancer, indicates a small study published online in the journal Gut.

The finding opens up the possibility of curbing the progress of one of the most difficult cancers to treat, by altering the balance of bacteria, say the authors. Pancreatic cancer usually spreads very quickly, and only around one in 20 patients is still alive five years after diagnosis.

The authors base their findings on an initial comparison of the bacteria found in the spit of 10 patients with pancreatic cancer, which had not yet spread, and 10 healthy people, matched for age and sex.

They found significant differences between the bacterial colonies in the two groups, with 31 additional species and 25 fewer species in the spit of the cancer patients.

They then checked spit samples from a further 28 pancreatic cancer patients and 28 healthy people to verify their findings.

And they checked tissue samples from 28 patients with chronic inflammation of the pancreas (chronic pancreatitis), which is associated with an increased risk of developing pancreatic cancer. Among six suspicious species, two -- Neisseria elongata and Streptococcus mitis -- showed up significantly less often in the mouths of the cancer patients than in those of their healthy peers, while levels of another species -- Granulicatella adjacens -- were significantly higher.

The combination of N Elongata and S mitis accurately differentiated between healthy patients and those with cancer in more than 80% cases.

Furthermore, they found similar differences in the prevalence of S mitis and G adjacens between the chronic pancreatitis samples and the spit of healthy people.

It is as yet unclear whether the presence of particular types of bacteria are a cause or effect of pancreatic cancer, say the authors. But their findings back previous research, which has implicated bacteria in the development of pancreatic diseases.

They go on to suggest that levels of certain bacteria could be used as a non-invasive and credible screen for pancreatic cancer, with the promise of earlier detection for a disease that has no clear symptoms in its early stages.

Monday, September 26, 2011

Cell Transplantation study shows bone growth from implanted tooth and dental pulp stem cells

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Researchers in Japan have completed a study showing that stem cells derived from deciduous canine teeth and dental pulp can be grafted and produce bone regeneration between parents and offspring. Their results are published in the current issue of Cell Transplantation (20:7), now freely available on-line.

"Bone defects can occur for a number of reasons, and autogenous bone grafting - using the patient's own bone - has been a standard approach to treatment," said study corresponding author Dr. Yoichi Yamada of the Center for Genetic and Regenerative Medicine at the Nagoya University School of Medicine. "However, considering severe invasiveness in self-donor bone sites, and the limited supply of autogenous bone, alternative donor sources are needed."

The researchers note that previous studies have shown that oral and maxillofacial dental tissues contain a variety of stem cells, such as dental pulp stem cells and stem cells from deciduous teeth. Stem cells, they note, can be easily extracted from deciduous teeth, which are routinely lost in childhood and generally discarded.

"Stem cells from human exfoliated deciduous teeth were identified as a novel population of stem cells, capable of differentiating into various cell types, such as osteoblasts, odontoblasts, adipocytes and neural cells," explained Dr. Yamada.

Their study extracted deciduous teeth from canine puppies and grafted them onto parent canine mandibles as an allograft. After four weeks, bone defects were prepared on both sides of the host mandible. The newly formed bone was evaluated at two, four and eight weeks. When compared to controls, the study group demonstrated well-formed mature bone and neovascularization.

The researchers reported that stem cells derived from dental pulp "display increased immunosuppressive activity when compared to bone marrow mesenchymal cells" and will likely have "immunosuppressive activity with potential clinical applications in allogenic in vivo stem cell transplantation, particularly for calcified tissue reconstruction."

Their pre-clinical study could pave the way for stem cell therapy in othropedics and oral maxillofacial reconstruction, concluded Dr. Yamata.

"This study highlights the promise of obtaining stem cells from unusual sources, such as teeth, and their potential benefit in familial treatments for bone reconstruction" said Dr. Julio Voltarelli, professor of Clinical Medicine and Clinical Immunology at the University of Sao Pãulo, Brazil, and section editor for Cell Transplantation. "Due to their potential to also become other cell types such as neural cells, it will be interesting to see what future studies reveal about the possible uses of these cells."

Tuesday, September 13, 2011

Sugar-free polyol gum, lozenges, hard candy; Nonfluoride varnishes help prevent cavities

Recommended in conjunction with fluoride for patients at high-risk for developing cavities

A multi-disciplinary expert panel, convened by the American Dental Association (ADA) Council on Scientific Affairs, issued a report this month containing clinical recommendations that sugar-free chewing gum, lozenges and hard candy including xylitol or polyol combinations, and a prescription varnish with chlorhexidine and thymol could be beneficial in preventing cavities when used as adjuncts to a comprehensive cavity prevention program which includes the use of fluoride-containing products.

The panel noted in its report that these nonfluoride options could provide an extra benefit to prevent cavities in patients at high risk for developing cavities when used in addition to products such as toothpaste, dental sealants and varnishes that contain fluoride as well as community water fluoridation and good eating habits.

The executive summary of the report entitled, "Nonfluoride Caries Preventive Agents," is published in the September issue of The Journal for the American Dental Association and is available on the EBD website. The clinical recommendations from the expert panel were reviewed and approved by the ADA's Council on Scientific Affairs.

The ADA recommends that clinicians determine a patient's risk for developing cavities by conducting a caries risk assessment, The Caries Form (Patients Ages 0-6 Years) and the Caries Form (Patients Over 6 Years) which includes completing a caries risk assessment form that can be used as a communications tool with their patients.

Nonfluoride agents


In addition to a comprehensive cavity-prevention program which includes the use of fluoride, the scientific panel recommended that clinicians consider applying a mixture of cholrhexidine-thymol varnish to the teeth of high-risk adults and the elderly every three months to reduce cavities developing in the root of the tooth.

The panel encouraged clinicians to consider advising parents and caregivers of healthy children older than 5 years who are at higher risk for cavities to chew sugar-free polyol gum after meals for 10 to 20 minutes to prevent cavities.

A polyol is a low-calorie sweetener such as xylitol, sorbitol or mannitol, which is not broken down by the bacteria in the mouth and therefore does not contribute to tooth decay. The panel also recommended that sucking xylitol-containing sugar-free lozenges or hard candy after meals may reduce cavities in children.

The panel's recommendations are based on a review of evidence from 71 published articles that described 50 randomized controlled trials and 15 nonrandomized studies to assess the effectiveness of various nonfluoride agents in preventing cavities.

ADA expert panels, Evidence-Based Dentistry


The clinical recommendations, developed by expert multidisciplinary panels convened by the ADA Council on Scientific Affairs, assessed available scientific evidence and developed practice-oriented recommendations through a comprehensive evidence-based process.

Evidence-based clinical recommendations are intended to provide dentists and other health professionals with a review of the latest scientific evidence on particular topics and are not considered a standard of care. Rather, health care professionals can consider clinical recommendations, patient preference and their own clinical judgment when diagnosing and treating patients.

Thursday, September 1, 2011

Caries-Preventive Agents: Nonfluoride Caries-Preventive Agents: Executive Summary of Evidence-Based Clinical Recommendations

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In this report, the authors present evidence-based clinical recommendations regarding the use of nonfluoride caries preventive agents. The recommendations were developed by an
expert panel convened by the American Dental Association (ADA)
Council on Scientific Affairs. The panel addressed several questions
regarding the efficacy of nonfluoride agents in reducing the incidence
of caries and arresting or reversing the progression of caries.

Types of Studies Reviewed


A panel of experts convened by
the ADA Council on Scientific Affairs, in collaboration with ADA
Division of Science staff, conducted a MEDLINE search to identify
all randomized and nonrandomized clinical studies regarding the
use of nonfluoride caries-preventive agents.

Results

The panel reviewed evidence from 50 randomized controlled
trials and 15 nonrandomized studies to assess the efficacy of
various nonfluoride caries-preventive agents.

Clinical Implications

The panel concluded that certain nonfluoride
agents may provide some benefit as adjunctive therapies in
children and adults at higher risk of developing caries. These recommendations
are presented as a resource for dentists to consider
in the clinical decision-making process.

Ω

Sealants and dental caries


The authors conducted a study to survey the perspectives of dentists
regarding the 2010 American Dental Association (ADA) recommendation to seal noncavitated carious lesions (NCCLs) in children and young adults.

Methods


The authors mailed a questionnaire
to a randomly selected sample of 2,400 general dentists
(GDs) and pediatric dentists (PDs) in the United States.
The sample was chosen by the ADA’s Survey Center. The
questionnaire included two photographs of NCCLs (permanent
first molar and premolar) in a 12-year-old child. Respondents
were provided with radiographic findings and asked to
choose from several management options.

Results

In the absence of radiographic evidence of caries,
37.4 percent and 42.3 percent of GDs and PDs, respectively,
indicated that they would seal the NCCL in the molar. For
the premolar, a significantly lower percentage of GDs than of
PDs indicated that they would seal the NCCL. With radiographic
evidence of caries in dentin, less than 4 percent of all
dentists surveyed indicated that they would seal the NCCLs,
and more than 90 percent indicated that they would remove
the caries and place restorations. Less than 40 percent of
dentists indicated that they sealed NCCLs in their practice.
Conclusions. The U.S. dentists surveyed have not adopted
evidence-based clinical recommendations regarding the
sealing of NCCLs.

Practice Implications


New educational and dissemination
programs should be developed regarding these evidence-based
caries management approaches.

Ω

Tuesday, August 30, 2011

Implant Prosthesis Offers an Improvement Over Dentures



As the number of older adults increases, more people are facing a reduced quality of life because of tooth loss. Edentulism is common among the elderly, and one survey estimates that 37 million Americans will need dentures by 2020. With this increasing demand comes an increasing need to offer a better solution.

An article in the current issue of the Journal of Oral Implantology reports on an alternative treatment to dentures. The “All-on-Four” therapy uses four implants to support a fixed prosthesis, and the patient’s new teeth can be put in place the day of surgery.

When compared with patients who have received implant therapy, those with dentures have shown only a marginal improvement in quality of life, according to clinical studies. These patients report pain, discomfort, poor stability, and difficulty eating. Dental clinicians see the need to offer replacements for natural teeth that allow greater satisfaction and improved quality of life for their patients.

The All-on-Four treatment maximizes the use of available bone and allows immediate functionality. Four implants are placed—two near the front and two near the back of the dental area. These support a fixed, full-arch prosthesis that is put in place the same day as the surgery. The success of this therapy is judged not only by its comfort and usability for the patient, but also by its longevity.

The authors evaluated the survival of the All-in-Four treatment for a 29-month period using the NobelActive implant from Sweden’s Nobel Biocare. This implant features a tapered body and variable thread design. Other All-on-Four implant designs have reported high survival rates between 92 percent and 100 percent.

In this study, 165 patients, with a mean age of 59 years, received 708 implants. No significant difference was found between the survival rates of implants in the maxilla and mandible jaws. Overall, the survival rate was 99.6 percent, with only three implants failing.

Full text of the article,
“The All-on-Four Immediate Function Treatment Concept With NobelActive Implants: A Retrospective Study,”
Journal of Oral Implantology, Vol. 37, No. 5, 2011, is available at http://allenpress.com/publications/journals/orim

About Journal of Oral Implantology
The Journal of Oral Implantology is the official publication of the American Academy of Implant Dentistry and of the American Academy of Implant Prosthodontics. It is dedicated to providing valuable information to general dentists, oral surgeons, prosthodontists, periodontists, scientists, clinicians, laboratory owners and technicians, manufacturers, and educators. The JOI distinguishes itself as the first and oldest journal in the world devoted exclusively to implant dentistry. For more information about the journal or society, please visit: http://www.joionline.org


Tuesday, August 23, 2011

Filling without drilling



Researchers at the University of Leeds have discovered a pain-free way of tackling dental decay that reverses the damage of acid attack and re-builds teeth as new.

The pioneering treatment promises to transform the approach to filling teeth forever.

Tooth decay begins when acid produced by bacteria in plaque dissolves the mineral in the teeth, causing microscopic holes or 'pores' to form. As the decay process progresses these micro-pores increase in size and number. Eventually the damaged tooth may have to be drilled and filled to prevent toothache, or even removed.

The very thought of drilling puts many people off going to see their dentist, whether or not they actually need treatment. This tendency to miss check-ups and ignore niggling aches and pains means that existing problems get worse and early signs of decay in other teeth are overlooked.

It's a vicious cycle, but one that can be broken, according to researchers at the University of Leeds who have developed a revolutionary new way to treat the first signs of tooth decay. Their solution is to arm dentists with a peptide-based fluid that is literally painted onto the tooth's surface. The peptide technology is based on knowledge of how the tooth forms in the first place and stimulates regeneration of the tooth defect.

"This may sound too good to be true, but we are essentially helping acid-damaged teeth to regenerate themselves. It is a totally natural non-surgical repair process and is entirely pain-free too," said Professor Jennifer Kirkham, from the University of Leeds Dental Institute, who has led development of the new technique.

The 'magic' fluid was designed by researchers in the University of Leeds' School of Chemistry, led by Dr Amalia Aggeli. It contains a peptide known as P 11-4 that - under certain conditions - will assemble together into fibres. In practice, this means that when applied to the tooth, the fluid seeps into the micro-pores caused by acid attack and then spontaneously forms a gel. This gel then provides a 'scaffold' or framework that attracts calcium and regenerates the tooth's mineral from within, providing a natural and pain-free repair.

The technique was recently taken out of the laboratory and tested on a small group of adults whose dentist had spotted the initial signs of tooth decay. The results from this small trial have shown that P 11-4 can indeed reverse the damage and regenerate the tooth tissue.

"The results of our tests so far are extremely promising," said Professor Paul Brunton, who is overseeing the patient testing at the University of Leeds Dental Institute. "If these results can be repeated on a larger patient group, then I have no doubt whatsoever that in two to three years time this technique will be available for dentists to use in their daily practice."

"The main reason that people don't go to the dentist regularly is fear. If we can offer a treatment that is completely non-invasive, that doesn't involve a mechanical drill, then we can change that perceived link between dental treatment and pain. This really is more than filling without drilling, this is a novel approach that enables the patients to keep their natural teeth!"

Sports Dental Injuries Are No Laughing Matter


Ω

The crunch of helmets as players tangle for a loose football, the swoosh of the net as an outside jumper is made and the crack of the bat as a guaranteed double sails into right center field are awesome sounds to sports fans but for dentists, they’re reminders that a player is just one misstep away from a dental injury.

“Basketball and baseball are the two biggest mouth-injuring sports,” says Stephen Mitchell, D.M.D., associate professor in the UAB Department of Pediatric Dentistry. “And the most common injuries we see are broken, displaced or knocked out teeth, and broken jaws.”

According to a report by the U.S. Surgeon General, craniofacial injuries sustained during sporting activities are a major source of nonfatal injury and disability in children and adults, accounting for up to one-third of all sports injuries. The National Youth Sports Safety Foundation estimates that more than 3 million teeth will be knocked out in youth sporting activities this year.

The increasing participation of girls and young women in competitive sports means that they, just like their male counterparts, should know the risks of dental injuries and use additional protective gear as appropriate, Mitchell says.
Mitchell says mouth guards and helmets with face protectors are the best way for kids to avoid dental injuries while playing sports.

“If the child has a full set of permanent teeth then a custom guard can be made that will provide protection but be small enough to make it easy to communicate with teammates,” Mitchell says. “But if they still have some of their baby teeth, a custom guard is a waste of money. Parents will be better off going to the store and buying one of the guards that can be boiled and molded to their child’s mouth.”

So what should you do if despite your best preventive efforts your child still hurts his or her teeth or jaw?

If a tooth is broken or cracked, see a dentist within 24 hours, Mitchell says. If a tooth or teeth have been displaced or knocked out, Mitchell says, take the child immediately to the emergency room and to try to preserve the tooth.

“A tooth that has been knocked out needs to be back in the mouth within 30 minutes for the best chance of long-term survival,” Mitchell says. He offers these tips for preserving the tooth, which can even help past the ideal 30-minute window:
• Avoid touching the root because it can be damaged easily.
• If the tooth is dirty, hold it by the upper part and rinse it off with milk until most of the dirt is washed away. If you don't have milk, don’t clean it. Wiping it off may cause more damage.
• If your child is old enough not to swallow it, try to gently put the tooth back in its socket for the best chance of preservation.
• If you can’t get it back in the socket, put it in a cup of milk and head for the dentist or emergency room.
“We tell people to put the tooth in milk because the cells around the root are still alive after it is knocked out and milk can provide nutrients to the cells to help keep them alive,” Mitchell adds. “Do not put the tooth in water. It can cause the cells to burst and makes saving the tooth much less likely.”
Jaw injuries may be much less obvious than a broken or knocked-out tooth but they are no less serious, Mitchell says. If a child falls hard enough to cut their chin, or takes an especially hard hit, it could easily cause breaks in the jaw. In an injury such as this, a child should be seen by a doctor within 24 hours.
No matter the injury, Mitchell says caring properly for the mouth afterward is key to successful healing.
“Following an injury a child’s mouth will be sore and they will want to do everything they can to make it not hurt. But, continuing to brush their teeth and practice good oral hygiene is extremely important,” he says. “It is the same as keeping any other wound clean, the cleaner the mouth is kept, the better it heals.”Home
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Sports Dental Injuries Are No Laughing Matter
Released: 8/22/2011 5:30 PM EDT
Source: University of Alabama at Birmingham
Newswise — BIRMINGHAM, Ala. – The crunch of helmets as players tangle for a loose football, the swoosh of the net as an outside jumper is made and the crack of the bat as a guaranteed double sails into right center field are awesome sounds to sports fans but for dentists, they’re reminders that a player is just one misstep away from a dental injury.
“Basketball and baseball are the two biggest mouth-injuring sports,” says Stephen Mitchell, D.M.D., associate professor in the UAB Department of Pediatric Dentistry. “And the most common injuries we see are broken, displaced or knocked out teeth, and broken jaws.”
According to a report by the U.S. Surgeon General, craniofacial injuries sustained during sporting activities are a major source of nonfatal injury and disability in children and adults, accounting for up to one-third of all sports injuries. The National Youth Sports Safety Foundation estimates that more than 3 million teeth will be knocked out in youth sporting activities this year.
The increasing participation of girls and young women in competitive sports means that they, just like their male counterparts, should know the risks of dental injuries and use additional protective gear as appropriate, Mitchell says.
Mitchell says mouth guards and helmets with face protectors are the best way for kids to avoid dental injuries while playing sports.
“If the child has a full set of permanent teeth then a custom guard can be made that will provide protection but be small enough to make it easy to communicate with teammates,” Mitchell says. “But if they still have some of their baby teeth, a custom guard is a waste of money. Parents will be better off going to the store and buying one of the guards that can be boiled and molded to their child’s mouth.”
So what should you do if despite your best preventive efforts your child still hurts his or her teeth or jaw?
If a tooth is broken or cracked, see a dentist within 24 hours, Mitchell says. If a tooth or teeth have been displaced or knocked out, Mitchell says, take the child immediately to the emergency room and to try to preserve the tooth.
“A tooth that has been knocked out needs to be back in the mouth within 30 minutes for the best chance of long-term survival,” Mitchell says. He offers these tips for preserving the tooth, which can even help past the ideal 30-minute window:
• Avoid touching the root because it can be damaged easily.
• If the tooth is dirty, hold it by the upper part and rinse it off with milk until most of the dirt is washed away. If you don't have milk, don’t clean it. Wiping it off may cause more damage.
• If your child is old enough not to swallow it, try to gently put the tooth back in its socket for the best chance of preservation.
• If you can’t get it back in the socket, put it in a cup of milk and head for the dentist or emergency room.

“We tell people to put the tooth in milk because the cells around the root are still alive after it is knocked out and milk can provide nutrients to the cells to help keep them alive,” Mitchell adds. “Do not put the tooth in water. It can cause the cells to burst and makes saving the tooth much less likely.”

Jaw injuries may be much less obvious than a broken or knocked-out tooth but they are no less serious, Mitchell says. If a child falls hard enough to cut their chin, or takes an especially hard hit, it could easily cause breaks in the jaw. In an injury such as this, a child should be seen by a doctor within 24 hours.
No matter the injury, Mitchell says caring properly for the mouth afterward is key to successful healing.

“Following an injury a child’s mouth will be sore and they will want to do everything they can to make it not hurt. But, continuing to brush their teeth and practice good oral hygiene is extremely important,” he says. “It is the same as keeping any other wound clean, the cleaner the mouth is kept, the better it heals.”

Thursday, August 18, 2011

Gaps in dental care coverage among retirees may lead to their delaying or stopping use of dental care


Retirees may be at risk for sporadic dental care or even stopping use due to dental coverage transitions and status of insurance, reports a new study released today in the American Journal of Public Health.


Researchers examined dental care utilization transition dynamics in the context of changing dental coverage status among a population around the age of retirement. They used data from the Health and Retirement Study (HRS) to assess the characteristics of persons aged 51 years and older based on whether they had maintained or changed their dental care use status between the 2004 and 2006 waves of HRS. They were particularly concerned with discovering how changes in dental coverage and changes in retirement status affected the relative likelihood of having irregular dental care utilization patterns.

The sample consisted of 16,345 individuals interviewed in both the 2004 and 2006 HRS, representing 74,047,165 members of the community-based population who were aged 51 years and older at the time of the 2004 interview. They found that Americans aged 51 years and older who lost dental coverage between the 2004 and 2006 survey periods were more likely to stop dental care use between periods, than those without coverage in both periods. Those who gained coverage were more likely to start dental care use between periods, than those without coverage in both periods.

The study’s authors said, “Although we were only able to look at a short time horizon with the HRS data and therefore do not know the longer-term use patterns of those who lose coverage around retirement age, even short-term lapses in preventive coverage can result in more invasive and costly procedures in the future. For retirees on fixed incomes, the high cost of dental procedures could have important financial consequences, and the delay of care could lead to worse overall health status and affect more than only dental costs.”

[From: “The Influence of Changes in Dental Care Coverage on Dental Care Utilization Among Retirees and Near-Retirees in the United States, 2004—2006.” ]

Monday, August 15, 2011

Can oral care for babies prevent future cavities?


Ω

New parents have one more reason to pay attention to the oral health of their toothless babies. A recent University of Illinois study confirms the presence of bacteria associated with early childhood caries (ECC) in infant saliva.

ECC is a virulent form of caries, more commonly known as tooth decay or a cavity. Cavities are the most prevalent infectious disease in U.S. children, according to the Centers for Disease Control and Prevention.

"By the time a child reaches kindergarten, 40 percent have dental cavities," said Kelly Swanson, lead researcher and U of I professor of animal science. "In addition, populations who are of low socioeconomic status, who consume a diet high in sugar, and whose mothers have low education levels are 32 times more likely to have this disease."

Swanson's novel study focused on infants before teeth erupted, compared to most studies focused on children already in preschool or kindergarten – after many children already have dental cavities.

"We now recognize that the "window of infectivity," which was thought to occur between 19 and 33 months of age years ago, really occurs at a much younger age," he said. "Minimizing snacks and drinks with fermentable sugars and wiping the gums of babies without teeth, as suggested by the American Academy of Pediatric Dentistry, are important practices for new parents to follow to help prevent future cavities."

In addition, his team used high-throughput molecular techniques to characterize the entire community of oral microbiota, rather than focusing on identification of a few individual bacteria.

"Improved DNA technologies allow us to examine the whole population of bacteria, which gives us a more holistic perspective," Swanson said. "Like many other diseases, dental cavities are a result of many bacteria in a community, not just one pathogen."

Through 454 pyrosequencing, researchers learned that the oral bacterial community in infants without teeth was much more diverse than expected and identified hundreds of species. This demonstration that many members of the bacterial community that cause biofilm formation or are associated with ECC are already present in infant saliva justifies more research on the evolution of the infant oral bacterial community, Swanson said.

Could manipulating the bacterial community in infants before tooth eruption help prevent this disease in the future?

"The soft tissues in the mouth appear to serve as reservoirs for potential pathogens prior to tooth eruption," he said. "We want to characterize the microbial evolution that occurs in the oral cavity between birth and tooth eruption, as teeth erupt, and as dietary changes occur such as breastfeeding vs. formula feeding, liquid to solid food, and changes in nutrient profile."

Swanson said educating parents-to-be on oral hygiene and dietary habits is the most important strategy for prevention of dental cavities.

Thursday, August 11, 2011

Dentists, Pharmacists Raise Awareness of Medication-Induced Dry Mouth



Leading dental and pharmacy organizations are teaming up to promote oral health and raise public awareness of dry mouth, a side effect commonly caused by taking prescription and over-the-counter medications. More than 500 medications can contribute to oral dryness, including antihistamines (for allergy or asthma), antihypertensive medications (for blood pressure), decongestants, pain medications, diuretics and antidepressants. In its most severe form, dry mouth can lead to extensive tooth decay, mouth sores and oral infections, particularly among the elderly.

Nearly half of all Americans regularly take at least one prescription medication daily, including many that produce dry mouth, and more than 90 percent of adults over age 65 do the same. Because older adults frequently use one or more of these medications, they are considered at significantly higher risk of experiencing dry mouth.

The American Dental Association (ADA), Academy of General Dentistry (AGD), American Academy of Periodontology (AAP) and the American Pharmacists Association (APhA) are collaborating to expand awareness of the impact of medications on dry mouth, a condition known to health professionals as xerostomia.

With regular saliva production, your teeth are constantly bathed in a mineral-rich solution that helps keep your teeth strong and resistant to decay. While saliva is essential for maintaining oral health and quality of life, at least 25 million Americans have inadequate salivary flow or composition, and lack the cleansing and protective functions provided by this important fluid.

“Each day, a healthy adult normally produces around one-and-a-half liters of saliva, making it easier to talk, swallow, taste, digest food and perform other important functions that often go unnoticed,” notes Dr. Fares Elias, president, Academy of General Dentistry. “Those not producing adequate saliva may experience some common symptoms of dry mouth.”

Signs and symptoms

At some point, most people will experience the short-term sensation of oral dryness because of nervousness, stress or just being upset. This is normal and does not have any long-term consequences. But chronic cases of dry mouth persist for longer periods of time. Common symptoms include trouble eating, speaking and chewing, burning sensations, or a frequent need to sip water while eating.

“Dry mouth becomes a problem when symptoms occur all or most of the time and can cause serious problems for your oral health,” explains Dr. Matthew Messina, ADA consumer advisor. “Drying irritates the soft tissues in the mouth, which can make them inflamed and more susceptible to infection.”

According to Dr. Messina, who practices general dentistry in the Cleveland area, without the cleansing and shielding effects of adequate saliva flow, tooth decay and periodontal (gum) disease become much more common. “Constant dryness and the lack of protection provided by saliva may contribute to bad breath. Dry mouth can make full dentures become less comfortable to wear because there is no thin film of saliva to help them adhere properly to oral tissues,” he adds. “Insufficient saliva can also result in painful denture sores, dry and cracked lips, and increased risks of oral infection.”

Common causes


Once considered an inevitable part of aging, dry mouth is now commonly associated with certain medications and autoimmune conditions such as Sjogren’s syndrome. Both of these can reduce salivary production or alter its composition, but experts agree that the primary cause of dry mouth is the use of medications.
Radiation treatment for head and neck cancer is also an important cause of severe dry mouth. The treatment can produce significant damage to the salivary glands, resulting in diminished saliva production and extreme dry mouth in many cases.
“Saliva plays an important role in maintaining oral health,” says Dr. Donald Clem, president of the American Academy of Periodontology. “With decreased saliva flow, we can see an increase in plaque accumulation and the incidence and severity of periodontal diseases.”

How to relieve dry mouth

Individuals with dry mouth should have regular dental checkups for evaluation and treatment. “Be sure to carry an up-to-date medication list at all times, and tell your dentist what medications you are taking and other information about your health at each appointment," advises Mr. Thomas Menighan, executive vice president and Chief Executive Officer, American Pharmacists Association. "In some cases, a different medication can be provided or your dosage modified to alleviate dry mouth symptoms. Talk to your pharmacist if you have any questions regarding your medication.”

Increasing fluid intake, chewing sugarless gum, taking frequent sips of water or sucking on ice chips can also help relieve dry mouth symptoms. Avoiding tobacco and intake of caffeine, alcohol and carbonated beverages may also help those with the condition. Your dentist may recommend using saliva substitutes or oral moisturizers to keep your mouth wet. Your local pharmacist is also a helpful source for information on products to help you manage dry mouth.

Tuesday, August 9, 2011

Ultraviolet-B and Vitamin D Reduce Risk of Dental Caries

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Large geographical variations in dental health and tooth loss among U.S. adolescents and young adults have been reported since the mid-1800s. The first study finding a north-south gradient in dental caries was a report of men rejected from the draft for the Civil War for lost teeth, from 8 per 1000 men in Kentucky to 25 in New England.

Studies by Clarence Mills and Bion East in the 1930s first linked the geographical variation in prevalence to sunlight exposure. They used data for adolescent males aged between 12 and 14 years from a cross-sectional survey in 1933–1934. East later found that dental caries were inversely related to mean hours of sunlight/year, with those living in the sunny west (3000 hours of sunlight/year) having half as many carious lesions as those in the much less sunny northeast (<2200 hours of sunlight/year).
Several studies conducted in Oregon in the 1950s noted that dental caries prevalence was lower in the sunnier regions of the state than in the cloudy regions, a finding that persisted after considering other factors that affect dental caries rates. The mechanism was attributed to vitamin D through its effects on calcium metabolism.

There were also several studies reported on vitamin D and dental caries in the 1920s and 1930s. May Mellanby and coworkers in Sheffield, England, did studies on the role of vitamin D on teeth in the 1920s. The first experiments were with dogs, where it was found that vitamin D stimulated the calcification of teeth. Subsequently, they studied the effect of vitamin D on dental caries in children, finding a beneficial effect. Additional studies were conducted on children in New York regarding dental caries with respect to season, artificial ultraviolet-B (UVB) irradiance, and oral intake of vitamin D with the finding that it took 800 IU/d to prevent caries effectively.
The mechanism whereby UVB reduces risk of dental caries is through production of vitamin D, followed by induction of cathelicidin, which attacks oral bacteria linked to dental caries. Cathelicidin is well known to fight bacterial infections, with findings reported for several bacterial infections including pneumonia, sepsis, and tuberculosis. Several recent papers reported that cathelicidin reduces the risk of caries, but did not link cathelicidin to vitamin D.

Serum 25-hydroxyvitamin D concentrations around 30-40 ng/ml (75-100 nmol/L) should significantly reduce the formation of dental caries. (The average white American has a level near 25 ng/ml, while the average black American has a level near 16 ng/ml.) To obtain these levels, oral intake of 1000-4000 IU/d of vitamin D3 or 15-20 minutes in the sun near solar noon in summer with 20-30% body surface area exposed is suggested.
Good dental health also involves a healthy diet low in sugar, regular tooth brushing, and regular dental checkups.

Use of vitamin D appears to be a better option for reducing dental caries than fluoridation of community water supplies as there are many additional health benefits of vitamin D and a number of adverse effects of water fluoridation such as fluorosis (mottling) of teeth and bones.

The paper is published online with open access:
Grant WB. A review of the role of solar ultraviolet-B irradiance and vitamin D in reducing risk of dental caries. Dermato-Endocrinology, 3:3, 1-6; July/August/September 2011; epub

Wednesday, August 3, 2011

Gum Disease Can Increase the Time It Takes to Become Pregnant

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Professor Roger Hart told the annual meeting of the European Society of Human Reproduction and Embryology that the negative effect of gum disease on conception was of the same order of magnitude as the effect of obesity.

Periodontal (gum) disease is a chronic, infectious and inflammatory disease of the gums and supporting tissues. It is caused by the normal bacteria that exist in everyone's mouths, which, if unchecked, can create inflammation around the tooth; the gum starts to pull away from the tooth, creating spaces (periodontal pockets) that become infected. The inflammation sets off a cascade of tissue-destructive events that can pass into the circulation. As a result, periodontal disease has been associated with heart disease, type 2 diabetes, respiratory and kidney disease, and problems in pregnancy such as miscarriage and premature birth. Around 10% of the population is believed to have severe periodontal disease. Regular brushing and flossing of teeth is the best way of preventing it.

Prof Hart, who is Professor of Reproductive Medicine at the University of Western Australia (Perth, Australia) and Medical Director of Fertility Specialists of Western Australia, said: "Until now, there have been no published studies that investigate whether gum disease can affect a woman's chance of conceiving, so this is the first report to suggest that gum disease might be one of several factors that could be modified to improve the chances of a pregnancy."

The researchers followed a group 3737 pregnant women, who were taking part in a Western Australian study called the SMILE study, and they analysed information on pregnancy planning and pregnancy outcomes for 3416 of them.

They found that women with gum disease took an average of just over seven months to become pregnant -- two months longer than the average of five months that it took women without gum disease to conceive.

In addition, non-Caucasian women with gum disease were more likely to take over a year to become pregnant compared to those without gum disease: their increased risk of later conception was 13.9% compared to 6.2% for women without gum disease. Caucasian women with gum disease also tended to take longer to conceive than those who were disease-free but the difference was not statistically significant (8.6% of Caucasian women with gum disease took over one year to conceive and 6.2% of women with gum disease).

Information on time to conception was available for 1,956 women, and of, these, 146 women took longer than 12 months to conceive -- an indicator of impaired fertility. They were more likely to be older, non-Caucasian, to smoke and to have a body mass index over 25 kg/m2. Out of the 3416 women, 1014 (26%) had periodontal disease.

Prof Hart said: "Our data suggest that the presence of periodontal disease is a modifiable risk factor, which can increase a woman's time to conception, particularly for non-Caucasians. It exerts a negative influence on fertility that is of the same order of magnitude as obesity. This study also confirms other, known negative influences upon time to conception for a woman; these include being over 35 years of age, being overweight or obese, and being a smoker. There was no correlation between the time it took to become pregnant and the socio-economic status of the woman.

"All women about to plan for a family should be encouraged to see their general practitioner to ensure that they are as healthy as possible before trying to conceive and so that they can be given appropriate lifestyle advice with respect to weight loss, diet and assistance with stopping smoking and drinking, plus the commencement of folic acid supplements. Additionally, it now appears that all women should also be encouraged to see their dentist to have any gum disease treated before trying to conceive. It is easily treated, usually involving no more than four dental visits.

"The SMILE study was one of the three largest randomised controlled trials performed in Western Australia. It showed conclusively that although treatment of periodontal disease does not prevent pre-term birth in any ethnic group, the treatment itself does not have any harmful effect on the mother or fetus during pregnancy."

Prof Hart said that the reason why pregnancies in non-Caucasian women were more affected by gum disease could be because these women appeared to have a higher level of inflammatory response to the condition.

Thursday, July 28, 2011

Study shows bone fluoride levels not associated with osteosarcoma

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The International and American Associations for Dental Research have released in its Journal of Dental Research a study that investigated bone fluoride levels in individuals with osteosarcoma, which is a rare, primary malignant bone tumor that is more prevalent in males. Since there has been controversy as to whether there is an association between fluoride and risk for osteosarcoma, the purpose of this study, titled "An Assessment of Bone Fluoride and Osteosarcoma," was to determine if bone fluoride levels were higher in individuals with osteosarcoma.

No significant association between bone fluoride levels and osteosarcoma risk was detected in this case-control study, based on controls with other tumor diagnoses.

In the case-control study, by lead researcher Chester Douglass of Harvard University, patients were identified by physicians in the orthopedic departments from nine hospitals across the U.S. between 1993 and 2000. In this report, the study sample included incident cases of primary osteosarcoma and a control group of patients with newly-diagnosed malignant bone tumors. Specimens of tumor-adjacent bone and iliac crest bone were analyzed for fluoride content. The study was approved by the Institutional Review Boards of the respective hospitals, Harvard Medical School and the Medical College of Georgia.

Logistic regression of the incident cases of osteosarcoma (N=137) and tumor controls (N=51), adjusting for age and sex and potential confounders of osteosarcoma, was used to estimate odds ratios (OR) and 95% confidence intervals (CI). There was no significant difference in bone fluoride levels between cases and controls. The OR adjusted for age, gender, a history of broken bones was 1.33 (95% CI: 0.56-3.15).

"The controversy over whether there is an association between fluoride and risk for osteosarcoma has existed since an inconclusive animal study 20 years ago," said IADR Vice-president Helen Whelton. "Numerous human descriptive and case-control studies have attempted to address the controversy, but this study of using actual bone fluoride concentrations as a direct indicator of fluoride exposure represents our best science to date and shows no association between fluoride in bone and osteosarcoma risk."