Tuesday, March 10, 2009

Evidence-Based Dentistry Web Site

Initial Database Features Over 1300 Systematic Reviews

The American Dental Association (ADA) announces the launching of EBD.ada.org (http://www.ebd.ada.org), the Web site dedicated to evidenced-based dentistry (EBD). EBD.ada.org allows easy and quick access to a database of systematic reviews of oral health clinical information from one centralized location.

EBD, according to the ADA, is an approach to oral health care that requires the judicious integration of systematic assessments of clinically relevant scientific evidence, relating to the patient's oral and medical condition and history, with the dentist's clinical expertise and the patient's treatment needs and preferences.

Supported by a grant from the National Library of Medicine and the National Institute for Dental and Craniofacial Research (grant number G08 LM008956), EBD.ada.org also features critical summaries of systematic reviews that assess information within systematic reviews in a concise format so that health care workers can incorporate scientific evidence in clinical decision making.

Key features of the EBD Web site include:

o A database of systematic reviews-- The database features over 1300 systematic reviews, with quarterly updating.

o Critical Summaries of systematic reviews -- One-page synopses of the key elements of a systematic review that a member of the dental team needs to know when making treatment decisions. Authors of the summaries are practicing dentists trained in critical assessment of published studies.

o Clinical Recommendations -- These provide evidence-based guidance on the application of current scientific evidence to patient care.

o Suggest Clinical Ideas-- A section where dentists can let the ADA know the clinical questions they encounter in trying to provide the best care to their patients.

o Links to other useful resources-- This central resource for EBD information will include links to many outside resources, including tutorials, glossaries, and databases.

"This is just a first step for EBD.ada.org," explains John S. Findley, D.D.S., ADA president. "We will continue to gather feedback to make sure the Web site provides the most clinically relevant and current information in a concise and user-friendly manner for dental and health care professionals."

Friday, March 6, 2009

Gene Responsible For Formation Of Enamel

"Subjects afflicted by DiGeorge syndrome exhibit teeth with enamel defects. We have demonstrated that a direct link between impaired Tbx1 function and enamel defects exists. Enamel forms via the mineralization of specific enamel proteins that are secreted by dental epithelial cells called ameloblasts. Our results clearly show that teeth of Tbx1 null mice lacked enamel and ameloblasts," explains Prof Mitsiadis.

Dentistry Of Future? Gene Responsible For Formation Of Enamel Discovered

A team of researchers lead by Professor Dr Thimios Mitsiadis at the University of Zurich, Switzerland, has identified a gene responsible for the formation of enamel, which is the key component of the teeth. The experiments were accomplished in mice carrying a deletion of the transcription factor Tbx1, a gene that plays a principal role in several human malformations (heart, thymus, parathyroid, face, and teeth) associated to the DiGeorge syndrome.

These findings, just published in Development Biology, represent a major contribution to the understanding of the production of enamel, the "hardest organic tissue" found in nature.

An American group of researchers from the University of Oregon have also shown a relationship between another transcription factor (Ctip2) and the production of enamel, but in the words of Prof Mitsiadis "our investigations better demonstrate the lack of enamel in teeth. Because of the early lethality of the Tbx1 mutant mice, we have used long-term culture techniques that allow the unharmed growth of teeth until their full maturity. No such studies were performed from our American colleagues."

Could dental treatment benefit in the future from this revolutionary study? The answer is definitively "yes." "The understanding of the genetic code controlling tooth development and repair will permit us to imagine and generate new products and replacement tissues for injured and unhealthy teeth. However the requirements for functional tooth repair and/or formation are complex. Yet, a single approach has not allowed an effective clinical therapy," says Prof Mitsiadis.

Is it possible to use dental stem cells to stimulate the growth of new enamel? This represents the biggest challenge in the discipline of tooth engineering. "Our results show that Tbx1 is involved in the maintenance of dental epithelial stem cells that are responsible for ameloblast formation. In some cases of genetic tooth anomalies, regeneration and repair of teeth could be treated by stem cells. Aggregates of dental stem cells could be used in the future for local transplantation in the dental tissues," explains Prof Mitsiadis

Thursday, March 5, 2009

Green tea for healthy teeth and gums

Recent study suggests that antioxidants in green tea may help reduce periodontal disease.

With origins dating back over 4,000 years, green tea has long been a popular beverage in Asian culture, and is increasingly gaining popularity in the United States. And while ancient Chinese and Japanese medicine believed green tea consumption could cure disease and heal wounds, recent scientific studies are beginning to establish the potential health benefits of drinking green tea, especially in weight loss, heart health, and cancer prevention. A study recently published in the Journal of Periodontology, the official publication of the American Academy of Periodontology (AAP), uncovered yet another benefit of green tea consumption. Researchers found that routine intake of green tea may also help promote healthy teeth and gums. The study analyzed the periodontal health of 940 men, and found that those who regularly drank green tea had superior periodontal health than subjects that consumed less green tea.

"It has been long speculated that green tea possesses a host of health benefits," said study author Dr. Yoshihiro Shimazaki of Kyushu University in Fukuoka, Japan. "And since many of us enjoy green tea on a regular basis, my colleagues and I were eager to investigate the impact of green tea consumption on periodontal health, especially considering the escalating emphasis on the connection between periodontal health and overall health."

Male participants aged 49 through 59 were examined on three indicators of periodontal disease: periodontal pocket depth (PD), clinical attachment loss (CAL) of gum tissue, and bleeding on probing (BOP) of the gum tissue. Researchers observed that for every one cup of green tea consumed per day, there was a decrease in all three indicators, therefore signifying a lower instance of periodontal disease in those subjects who regularly drank green tea.

Green tea's ability to help reduce symptoms of periodontal disease may be due to the presence of the antioxidant catechin. Previous research has demonstrated antioxidants' ability to reduce inflammation in the body, and the indicators of periodontal disease measured in this study, PD, CAL and BOP, suggest the existence of an inflammatory response to periodontal bacteria in the mouth. By interfering with the body's inflammatory response to periodontal bacteria, green tea may actually help promote periodontal health, and ward off further disease. Periodontal disease is a chronic inflammatory disease that affects the gums and bone supporting the teeth, and has been associated with the progression of other diseases such as cardiovascular disease and diabetes.

"Periodontists believe that maintaining healthy gums is absolutely critical to maintaining a healthy body," says Dr. David Cochran, DDS, PhD, President of the AAP and Chair of the Department of Periodontics at the University of Texas Health Science Center at San Antonio. "That is why it is so important to find simple ways to boost periodontal health, such as regularly drinking green tea – something already known to possess certain health-related benefits."