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.