Two-step tooth implantation and built-up bone can be longer lasting

Periodontists routinely grow bone in the mouth to guarantee a stable environment for teeth and tooth implants. But whether it's better to build up bone before placing the implant, or to simply place the implant and allow bone to grow around it, has been a subject of considerable medical debate.

Now Prof. Zvi Artzi of Tel Aviv University's Maurice and Gabriela Goldschleger School of Dentistry at the Sackler Faculty of Medicine has completed a study that concludes the two-step method is the more effective alternative — building bone first, then implanting and allowing further bone growth. Currently, many dental professionals prefer a one-step process to save their patients from an additional surgical procedure.

Published in the Journal of Clinical Periodontology, Prof. Artzi's study shows that a one-step implant will show more wear and tear over time than one implanted through the more cautious two-step procedure. While both are clinically effective methods, he concludes, implant placement procedures done with the one-step method show greater bone resorption around the implant neck — a process by which the bone is broken down. Bonding of the bone around the implant was also shown to be inferior.

Testing proven procedures

The successful placement of a tooth implant is based on the biocompatibility of titanium, the main component of most dental and orthopedic implants. Both animal and human tissues readily accept the implant and grow around it. But in many cases, the amount of bone is also crucial to the success of the implant. Building bone to stabilize a titanium fixture is a long-standing procedure in dentistry.

Periodontists typically choose either the one-step or two-step procedure based on their preference alone. So Prof. Artzi and his fellow researchers set out to determine which procedure was scientifically superior in the long-term, well past the time when periodontists would typically monitor a patient's progress. In their study, they compared both methods of implantation in lab animals, and followed the progress of the implants over a course of two years.

The one-step procedure is based on the idea that a bone graft will simply attract the surrounding tissue to build up bone around the titanium implant — a process called conduction. The benefit of this procedure is that patients are only subjected to one surgery. But the study shows a difference in long-term efficacy, Prof. Artzi says. Ultimately, the bone recedes less in the more cautious two-step procedure. The quality of the resulting bone itself is similar.

A judgement call

Though the study proves that the two-step method is more advantageous in most cases, each case is different, says Prof. Artzi. For example, dental professionals also take into account the already existing bone – which determines how stable a future implant will be – before deciding which route to take with each individual patient. Clinically, both methods remain sound, and periodontists should still rely on their own judgement as to what is best for the patient.

Sports and Energy Drinks Responsible for Irreversible Damage to Teeth

Energy drinks found twice as likely to destroy enamel than sports drinks

A recent study published in the May/June 2012 issue of General Dentistry, the peer-reviewed clinical journal of the Academy of General Dentistry, found that an alarming increase in the consumption of sports and energy drinks, especially among adolescents, is causing irreversible damage to teeth—specifically, the high acidity levels in the drinks erode tooth enamel, the glossy outer layer of the tooth.

“Young adults consume these drinks assuming that they will improve their sports performance and energy levels and that they are ‘better’ for them than soda,” says Poonam Jain, BDS, MS, MPH, lead author of the study. “Most of these patients are shocked to learn that these drinks are essentially bathing their teeth with acid.”

Researchers examined the acidity levels in 13 sports drinks and nine energy drinks. They found that the acidity levels can vary between brands of beverages and flavors of the same brand. To test the effect of the acidity levels, the researchers immersed samples of human tooth enamel in each beverage for 15 minutes, followed by immersion in artificial saliva for two hours. This cycle was repeated four times a day for five days, and the samples were stored in fresh artificial saliva at all other times.

“This type of testing simulates the same exposure that a large proportion of American teens and young adults are subjecting their teeth to on a regular basis when they drink one of these beverages every few hours,” says Dr. Jain.

The researchers found that damage to enamel was evident after only five days of exposure to sports or energy drinks, although energy drinks showed a significantly greater potential to damage teeth than sports drinks. In fact, the authors found that energy drinks caused twice as much damage to teeth as sports drinks.

With a reported 30 to 50 percent of U.S. teens consuming energy drinks, and as many as 62 percent consuming at least one sports drink per day, it is important to educate parents and young adults about the downside of these drinks. Damage caused to tooth enamel is irreversible, and without the protection of enamel, teeth become overly sensitive, prone to cavities, and more likely to decay.

“Teens regularly come into my office with these types of symptoms, but they don’t know why,” says AGD spokesperson Jennifer Bone, DDS, MAGD. “We review their diet and snacking habits and then we discuss their consumption of these beverages. They don’t realize that something as seemingly harmless as a sports or energy drink can do a lot of damage to their teeth.”

Dr. Bone recommends that her patients minimize their intake of sports and energy drinks. She also advises them to chew sugar-free gum or rinse the mouth with water following consumption of the drinks. “Both tactics increase saliva flow, which naturally helps to return the acidity levels in the mouth to normal,” she says.

Also, patients should wait at least an hour to brush their teeth after consuming sports and energy drinks. Otherwise, says Dr. Bone, they will be spreading acid onto the tooth surfaces, increasing the erosive action.

Fish Oil Could Be Therapy for Periodontal Disease

Periodontitis, inflammation of the tissue surrounding the teeth, affects more than half of adults and is linked to an increased risk of stroke and other heart problems. To evaluate whether fish oil supplementation could be an adjunct therapy for periodontitis, Dr. Alison Coates from the University of South Australia and colleagues from the School of Dentistry at University of Adelaide in Australia reviewed evidence from eight unique studies that involved humans.

Their review of these studies showed that improvements in clinical measures were common in all studies, but were scientifically significant in two that used a combination of fish oil and aspirin. Although this is not conclusive evidence, intake of fish oil is recommended for health benefits beyond the teeth.

"I would recommend that people ensure they have a sufficient intake of long chain omega-3 fatty acids in their diet for general health," said Coates. "In Australia, these types of fatty acids are considered to be essential with ~500 mg recommended as the suggested dietary target. This equates to approximately 2 fatty fish meals per week."

There are no serious dangers to consuming fish oil. At high levels of fish oil above the GRAS limit, people may experience a delayed clotting time and at very high doses potential gastric upset. If people are taking blood thinning medication, then they should consult with a doctor.

The group reports that the evidence for fish oil being effective in reducing periodontal symptoms is building but there is a need for more well designed studies that evaluate the supplement both alone and in combination with aspirin to be able to tease out whether fish oil by itself is effective. It is important that compliance to treatment is considered and that the dose and length of supplementation is appropriate. A clinical trial is underway in Australia that is investigating the effects of fish oil as adjunct therapy for periodontitis.

IADR/AADR publish studies on severe early childhood caries

New classification proposed

The International and American Associations for Dental Research have published two studies about dental caries in children. These articles, titled "Hypoplasia-Associated Severe Early Childhood Caries – A Proposed Definition" (lead author Page Caufield, New York University College of Dentistry) and "Deciduous Molar Hypomineralization and Molar Incisor Hypomineralization" (lead author M.E.C. Elfrink, Academic Centre for Dentistry, Amsterdam) discuss the definitions of dental caries susceptibility to the hypomineralization and hypoplasia.

The study by Caufield et al proposes a new classification of severe early childhood caries (S-ECC) called hypoplasia-associated severe early childhood caries (HAS-ECC). This form of caries affects mostly young children living at or below poverty, characterized by structurally damaged primary teeth that are particularly vulnerable to dental caries. These predisposing developmental dental defects are mainly permutations of enamel hypoplasia (EHP). Anthropologists and dental researchers consider EHP an indicator for infant and maternal stresses including malnutrition, a variety of illnesses and adverse birthing conditions. Differentiation of HAS-ECC from other forms of early childhood caries is warranted due to its distinct etiology, clinical presentation and eventual management.

According to the study, defining HAS-ECC has important clinical implications: therapies that control or prevent other types of caries are likely to be less effective with HAS-ECC because the structural integrity of the teeth is compromised prior to their emergence into the oral cavity. The study suggests that to prevent HAS-ECC, dentists must partner with other health providers to develop interventions that begin with pregnant mothers with the aim of eliminating or ameliorating the covariates accompanying poverty, including better pre- and postnatal care and nutrition.

The study by Elfrink et al was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between deciduous molar hypomineralization (DMH) and permanent molar incisor hypomineralization (MIH). First permanent molars develop during a period similar to that of second primary molars, with possible comparable risk factors for hypomineralization. Children with DMH have a greater risk of developing MIH. In this study, clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6,161 children (49.8% girls; mean age 74.3 mos, SD ± 5.8). First permanent molars and second primary molars were scored with respect to DMH or MIH. The prevalence of DMH and MIH was 9.0% and 8.7% at child level, and 4.0% and 5.4% at tooth level. The odds ratio for MIH based on DMH was 4.4 (95% CI, 3.1-6.4). The relationship between the occurrence of DMH and MIH suggests a shared cause and indicates that, clinically, DMH can be used as a predictor for MIH.

"Data from over 6,000 children show that children with hypomineralization in the deciduous dentition (DMH: prevalence 9.0%) have a greater risk of developing hypomineralization in the permanent dentition (MIH; prevalence 8.7%)," said J.M. ten Cate, professor at Academisch Centrum Tandheelkunde Amsterdam and co-author of the study titled "Deciduous Molar Hypomineralization and Molar Incisor Hypomineralization". "Therefore, in clinical practice, extra attention needs to be paid to children with DMH in the period when their permanent molars and incisors are erupting, given their increased risk of having MIH."

Satu Alaluusua, University of Helsinki, Institute of Dentistry, Finland, wrote a corresponding perspective article entitled "Defining Developmental Enamel Defect-Associated Caries: Where are we now?" In it, she states that it would be of value to distinguish hypoplasia associated severe early childhood careers as a subgroup of S-ECC and she emphasizes that developmental enamel defects whether hypoplasia, hypomineralization or in combination can increase caries risk.

Saliva test could dramatically increase detection of oral cancer

A Michigan State University surgeon is teaming up with a Lansing-area dental benefits firm on a clinical trial to create a simple, cost-effective saliva test to detect oral cancer, a breakthrough that would drastically improve screening and result in fewer people dying of the world's sixth most common cancer.

Barry Wenig, a professor in the College of Human Medicine's Department of Surgery and lead investigator on the project, is working with Delta Dental of Michigan's Research and Data Institute to compile study data and recruit dentists. The study will enroll 100-120 patients with white lesions or growths in their mouths and tonsil areas to test as part of the clinical trial.

Wenig and his team will be looking for certain biomarkers previously identified by researchers at UCLA; the biomarkers have been shown in studies to confirm the presence of oral cancer. By creating a simple saliva test which could identify the biomarker's presence, physicians and dentists would know which patients need treatment and which ones could avoid needless and invasive biopsies.

"Most white lesions are benign, so a majority of people who develop them are getting biopsies that are not needed," Wenig said. "Conversely, a simple test would allow us to identify those patients with malignant lesions and get them into treatment quicker."

Oral cancer has a poor survival rate linked to late detection, Wenig said: Only 60 percent of patients live beyond five years after diagnosis. Among black males, the survival rate is less than 38 percent.

"The key challenge to reduce the mortality and morbidity of oral cancer is to develop strategies to identify and detect the disease when it is at a very early stage," he said.

In addition to Delta Dental's Research and Data Institute, which works with researchers from leading universities to monitor advances in science, Wenig is collaborating with PeriRx, a Pennsylvania company that will sponsor upcoming trials with the Food and Drug Administration.

"The results of this trial could be life changing for many people," said Jed Jacobson, chief science officer at Delta Dental and a licensed dentist. "It is a tremendous opportunity for the dental community to participate in what could be a groundbreaking research project."

Wenig and members of his team recently returned from southern California, where they met with UCLA colleagues, who are working to develop saliva diagnostic tests for other cancers as well.

"These tests are as noninvasive as it gets; patients simply need to spit into a cup," Wenig said. "The ease of the test will greatly expand our ability to effectively screen for the cancerous lesions.

"Right now, there are no early screenings available for most head and neck cancers."

The test also has the potential to accelerate health care savings, he added, since the number of biopsies can be dramatically reduced.

Anyone seeking more information on the trial can call the Department of Surgery at (517) 267-2042.

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Study hints at why gums suffer with age

New research from Queen Mary, University of London in collaboration with research groups in the USA sheds light on why gum disease can become more common with old age.

The study, published in Nature Immunology, reveals that the deterioration in gum health which often occurs with increasing age is associated with a drop in the level of a chemical called Del-1.

The researchers say that understanding more about Del-1 and its effects on the body’s immune system could help in the treatment or prevention of serious gum disease.

Periodontitis is a disease of the gums which causes bleeding and bone loss which can, over time, lead to loss of teeth. It affects about 20 per cent of the UK population and is caused by an over-active immune response to bacteria that grow in the mouth.

As people age they are more likely to suffer from inflammatory diseases, including gum disease.

The new research investigated gum disease in young and old mice and found that an increase in gum disease in the older animals was accompanied by a drop in the level of Del-1. This protein is known to restrain the immune system by stopping white blood cells from sticking to and attacking mouth tissue.

Mice that had no Del-1 developed severe gum disease and elevated bone loss and researchers found unusually high levels of white blood cells in the gum tissue.

When they treated the gums of the mice with Del-1, the number of white blood cells dropped, and gum disease and bone loss were reduced.

The researchers say their findings could be the basis for a new treatment or prevention of gum disease.

Mike Curtis is Professor of Microbiology at Queen Mary, University of London, Director of the Blizard Institute and the lead on the microbiological studies in the research. He said: “Periodontitis is an extremely common problem and we know that the disease tends to be more common as we get older.

“This research sheds some light on why ageing makes us more susceptible and understanding this mechanism is the first step to an effective treatment.”

Dental X-rays Should be Used Sparingly To Reduce Radiation Risk

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Dental X-rays linked to common brain tumor

The American Dental Association (ADA) says that it is aware of a recent study that associates yearly or more frequent dental X-rays to an increased risk of developing meningioma, the most commonly diagnosed brain tumor. The ADA’s long-standing position is that dentists should order dental X-rays for patients only when necessary for diagnosis and treatment. Since 1989, the ADA has published recommendations to help dentists ensure that radiation exposure is as low as reasonably achievable.

Meningioma, the most common primary brain tumor in the United States, accounts for about 33 percent of all primary brain tumors. The most consistently identified environmental risk factor for meningioma is exposure to ionizing radiation. In the largest study of its kind, researchers from Brigham and Women's Hospital (BWH), Yale University School of Medicine, Duke University, UCSF and Baylor College of Medicine have found a correlation between past frequent dental x-rays, which are the most common source of exposure to ionizing radiation in the U.S, and an increased risk of developing meningioma. These findings are published in the April 10, 2012 issue of Cancer.

"The findings suggest that dental x-rays obtained in the past at increased frequently and at a young age, may be associated with increased risk of developing this common type of brain tumor," said Elizabeth Claus, MD, PhD, a neurosurgeon at BWH and Yale University School of Medicine at New Haven. "This research suggests that although dental x-rays are an important tool in maintaining good oral health, efforts to moderate exposure to this form of imaging may be of benefit to some patients."

Claus and her colleagues studied data from 1,433 patients diagnosed with meningioma between 20 and 79 years of age between May 2006 and April 2011 and compared the information to a control group of 1350 participants with similar characteristics. They found that patients with meningioma were twice as likely to report having a specific type of dental x-ray called a bitewing exam, and that those who reported having them yearly or more frequently were 1.4 to 1.9 times as likely to develop a meningioma when compared to the control group. Additionally, researchers report that there was an even greater increased risk of meningioma in patients who reported having a panorex x-ray exam. Those who reported having this exam taken under the age of 10, were 4.9 times more likely to develop a meningioma compared to controls. Those who reported having the exam yearly or more frequently than once a year were nearly 3 times as likely to develop meningioma when compared to the control group.

"It is important to note that the dental x-rays performed today use a much lower dose of radiation than in the past," said Claus.

According to background information in the study, The American Dental Association's statement on the use of dental radiographs emphasizes the need for dentists to examine the risks and benefits of dental x-rays and confirms that there is little evidence to support the use of dental x-rays in healthy patients at preset intervals.

The ADA has reviewed the study and notes that the results rely on the individuals’ memories of having dental X-rays taken years earlier. Studies have shown that the ability to recall information is often imperfect. Therefore, the results of studies that use this design can be unreliable because they are affected by what scientists call “recall bias.” Also, the study acknowledges that some of the subjects received dental x-rays decades ago when radiation exposure was greater. Radiation rates were higher in the past due to the use of old x-ray technology and slower speed film. The ADA encourages further research in the interest of patient safety.

As part of the ADA’s recommendations to minimize radiation exposure, the ADA encourages the use of abdominal shielding (e.g., protective aprons) and thyroid collars on all patients. In addition, the ADA recommends that dentists use E or F speed film, the two fastest film speeds available, or a digital x -ray.
In addition to the X-ray recommendations, the ADA’s Council on Scientific Affairs will publish clinical guidance on the use of cone-beam computed tomography in an upcoming issue of The Journal of the American Dental Association. The ADA will share these recommendations as soon as they are available.

Dental X-rays are valuable in helping dentists detect and treat oral health problems at an early stage. Many oral diseases can’t be detected on the basis of a visual and physical examination alone, and dental X-rays are valuable in providing information about a patient’s oral health such as early-stage cavities, gum diseases, infections or some types of tumors. How often dental X-rays should be taken depends on the patient’s oral health condition, age, risk for disease and any signs and symptoms of oral disease that the patient might be experiencing.

The ADA encourages patients to talk to their dentists if they have questions about their dental treatment. As a science-based organization, the ADA fully supports continuing research that helps dentists deliver high-quality oral health care safely and effectively.