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.