Cochrane review of fluoride dentifrices

Fluoride toothpastes are more effective than non-fluoride toothpastes at reducing cavities, say researchers from the Cochrane Oral Health Group in the US. The review appears in the January issue of The Cochrane Library, a quarterly electronic collection of evidence-based systematic reviews of data from health care studies prepared by the Cochrane Collaboration.
The reviewers assessed 74 studies conducted between 1950 and 2001 in the Americas, Europe and Asia involving more than 42,000 subjects under age sixteen, finding that regular brushing with fluoridated toothpaste results in 24 percent fewer cavities than brushing with non-fluoridated toothpaste.
* brushing with a fluoride toothpaste at least once a day reduces caries-even if children live in areas with fluoridated water supplies
* brushing twice a day with a fluoride toothpaste confers greater caries reduction than brushing once a day or less
* using a fluoride toothpaste may confer greater caries benefit in children and adolescents with higher baseline levels of decayed, missing and filled teeth.

ADA statement on amalgam

The American Dental Association reports that there is no link between exposure to mercury from dental amalgam and any detectable cognitive dysfunction, according to a study published in the peer-reviewed journal Environmental Health Perspectives. The study comprised a survey of 550 adults with no occupational exposure to mercury, and assessed mercury exposure in each subject, based on the total number of amalgam surfaces, the number of occlusal amalgam surfaces and urinary mercury concentration. Cognitive function was assessed through a neuro-psychological test battery and structured questionnaire. Exposure levels in the sample were low, based on urinary mercury concentrations. No measure of exposure was significantly associated with the scores on any neuropsychological test, said the researchers. They concluded, 'The benefits of amalgam over other currently available restorative materials have been well described. Given the level of concern regarding amalgam safety among the public and dental profession, our results are reassuring in that exposure to amalgam-derived mercury is not associated with detectable subtle neuropsychological deficits.'
The ADA also reported to the House of Representatives recently on the same subject. Click here for a copy of the report in Word.

Streptococcus mutans genome sequence

Scientists from the University of Oklahoma have deciphered the entire genome sequence of Streptoccocus mutans, the main organism implicated in causing tooth decay. Researchers can now download the sequence from the Internet.
The S. mutans sequence, which contains two million base pairs, will help scientists to identify genes that might be potential targets for new therapies in treating tooth decay. By targeting the genes responsible for adherence, for example, scientists may be able to develop a way to prevent the bacterium from sticking to teeth where the acids it produces can damage enamel. The sequence data for S. mutans is available on the Internet at www.genome.ou.edu/smutans.html, in the Oral Pathogen Sequence Databases, and through GenBank (accession number AE014133).

ENDOCARDITIS PROPHYLAXIS IDENTITY CARD

The Dental Health Foundation, in association with the Dental and Cardiology departments, Our Lady's Hospital for Sick Children, Crumlin, launched an "ENDOCARDITIS PROPHYLAXIS IDENTITY CARD" in February 2002 to mark the foundation's "St Apollonia Annual Event". In Ireland about one baby in a hundred is born with congenital heart disease, and most of these are at risk of developing infective carditis. As this can be associated with a bacteraemia induced by some dental procedures, paediatric cariologists in Cork and Dublin will issue a "Prevention of Endocarditis" card to inform the dentist of the child's condition, and the antibiotic prophylaxis regimes recommended before undertaking dental procedures that result in bleeding.The recommendations are as follows:

Child over 10 years: Single dose amoxycillin 3g orally 1 hour before dental procedure
Child 5-10 years: Single dose amoxycillin 1.5g orally 1 hour before dental procedure
Child under 5 years: Single dose amoxycillin 750mg orally 1 hour before dental procedure

Children who are allergic to Amoxycillin, Ampicillin or Penicillin
Child over 10 years: Azithromycin capsule or suspension 500mg 1 hour before dental procedure
Child 5-10 years: Azithromycin suspension 300mg 1-2 hours before dental procedure
Child under 5 years: Azithromycin suspension 200mg 1-2 hours before dental procedure

Potential Risk for Lead Exposure in Dental Offices, says CDC

Lead-lined boxes used to store intraoral dental film and film stored in them create an avoidable potential exposure risk for lead and should be disposed of immediately.

  A potential risk for lead exposure exists in some dental offices. In the past, the need to protect intraoral dental film from scatter radiation led to the use of lead-lined film storage boxes in dental offices. These boxes and the film in them were found to contain lead powder. Forty-three of 240 (18%) dental offices with radiograph equipment visited in Wisconsin between January and March, 2001 used these lead-lined boxes. The lead powder could be transferred to patients undergoing dental radiograph procedures via the hygienist's fingers and the film itself. Because advances in dental radiograph technology have reduced scatter radiation, lead-lined radiograph storage boxes are no longer necessary. Dental offices still using these boxes should dispose of them, and any film in them, immediately

CDC Hand Hygiene Guide

The Centers for Disease Control and Prevention has released a new Hand Hygiene Guideline for all health care personnel. CDC and American Dental Association in 2003 will be issuing revised recommendations for infection control in the dental surgery. The complete CDC Hand Hygiene Guideline is available online

Light Manipulation Could Replace X-ray

Scientists have discovered a way to shift the frequency of light beams to any desired colour, with near 100-per-cent efficiency, reports New Scientist. Photonics crystal pioneer John Joannopoulos and his group at MIT will publish their findings in the forthcoming edition of Physical Review Letters.If this effect can be harnessed it will revolutionise a range of fields turning heat into light, or terahertz rays. Joannopoulos et al have passed shock waves through a photonic crystal - made by sandwiching together layers of material that bend light in different ways. The crystals are used to steer light through circuits in the same way that electronic circuits direct electric current. By changing the way the crystal is built up, it is possible to control exactly which frequencies can go into the crystal and which come out. One of the benefits of pushing the frequency of light downwards would be the ability to make terahertz radiation. Terahertz rays, in the range between microwaves and infrared, hold great promise for medical imaging, as they are easier to focus and less damaging than X-rays, says New Scientist, but they are not yet widely used as they have been too difficult to produce.