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The first issue concerned fluoride and emerged following the release of a study of the carcinogenicity of fluoride in drinking water. The study, conducted by the National Toxicology Program of the National Institute of Environmental Health Sciences, found "equivocal" evidence of bone cancer in 3 male rats fed high dosages of fluoride and 1 male rat fed a mid-high dosage. However, no bone cancers were found in female rats or male and female mice in the same study.
The Assistant Secretary for Health subsequently established an expert subcommittee of his Committee to Coordinate Environmental Health and Related
Programs (CCHERP), asking it to conduct a searching review of the world literature and include new studies being conducted by the National Cancer Institute. The Committee's report was issued in February. Its most important finding, based on animal experiments and over 50 epidemiological studies including the latest NCI study, is that there is no evidence that optimal levels of fluoride cause cancer of any kind in animals or human beings. Furthermore, it supports the use of water fluoridation as the most costeffective and equitable method of preventing tooth decay, benefiting rich and poor alike. The report found that mild forms of dental fluorosis (a staining and mottling of enamel) have increased, probably because of widespread availability of fluoride products and their inappropriate use in some cases. The report concludes with research recommendations which generally parallel those in the NIDR long-range plan.
A second issue to emerge in 1990 raised the question of whether toxic amounts of mercury can accumulate in the body as a result of the placement of mercury-containing amalgam fillings and the subsequent release of mercury
Research to date has not proved that
vapor during chewing or toothbrushing.
individuals hypersensitive to the metal. However, we will continue to investigate the health effects of mercury, including the possibility of conducting population studies. A technology asessment conference on the biocompatibility of all dental materials is scheduled for July, and we are continuing research to develop alternative materials--ones that will be as durable as amalgams, but esthetically preferable, and also requiring less drilling and removal of sound tooth substance. Finally, a new CCHERP
subcommittee has been formed and charged by the Assistant Secretary to conduct
a complete investigation.
A report is expected later this year.
The third issue concerns the case of the Florida dentist who allegedly was responsible for the transmission of the AIDS virus to three of his patients. We may never know how this transmission occurred, but the Centers for Disease Control suspects that there were lapses in infectivity control procedures. We have formed an internal working group to explore this issue. While there are complex regulatory, legal, and ethical concerns involved, there are also research issues relating to infection control and compliance.
Mr. Chairman, the FY 1992 request for the National Institute of Dental
Research is $160,939,000.
BIOGRAPHICAL SKETCH OF DR. HARALD LÖE
Director, National Institute of Dental Research
Birthplace and Date: July 19, 1926, Steinkjer, Norway
Education: Oslo University, Norway, D.D.S., 1952; Dr. Odont, 1961
Professional History: 1974-1982, Dean and Professor of Periodontology, School of
Honorary Doctorate Degrees: University of Detroit, 1990; Medical University of
Honors Awards: Honored by His Majesty the King of Norway (Royal Norwegian Order
International Dental Studies, 1983; Gold Medal, University of Ghent, 1982; Centennial Award, University of California School of Dentistry, 1982; Award of Merit, Hartford Dental Society, 1982; Irving Glickman Memorial Lecture, Tufts University, 1979; William J. Gies Award, American Academy of Periodontology, 1978; Arthur Merritt Memorial Lecture, Baylor University, 1977; Certificate of Achievement, Connecticut Society of Periodontists, 1976; Massachusetts Dental Society International Award, 1973; honored by Her Majesty the Queen of Denmark (Knight of Danebrog), 1972; International Association for Dental Research Award for Basic Research in Periodontics, 1969; Honorary memberships in several professional societies around the world.
Other Professional Activities: Author of more than 275 scientific articles; international lecturer; honorary member and elected fellow of scientific and learned societies here and abroad.
GUIDELINES FOR HEALTH CARE PROVIDERS
Senator HARKIN. Thank you very much, Dr. Löe.
Obviously, one of the questions I had was on the silver fillings, and you have answered that, and I appreciate that. We look forward to that study toward the end of this year.
The other question that we hear a lot about, of course, is AIDS and the transmission of AIDS, the dentist in Florida. Is there a need for any additional guidelines in this area?
Dr. LOE. At this point CDC is examining the issues. They have already had two meetings on this particular problem and to explore the possibility of issuing new regulations. Both the American Dental Association and the American Medical Association have issued guidelines for their professions on the management of patients by health providers who are HIV positive. So, I think we are in the middle of discussing the issues at the moment.
For our part, when you look back on it, we have had 10 years of experience with AIDS, and so far we know of only one practice where the disease was transmitted from health provider to patient. The evidence for that is also circumstantial, by the way, and no one really has a fix on how this happened. This is another area we need to know more about before we issue firm and severe guidelines or regulate health providers in practice.
Senator HARKIN. Dr. Löe, thank you very much.
QUESTIONS SUBMITTED BY THE SUBCOMMITTEE
Senator HARKIN. There will be some additional questions which will be submitted for your response in the record.
[The following questions were not asked at the hearing, but were submitted to the Institute for response subsequent to the hearing:]
QUESTIONS SUBMITTED BY THE SUBCOMMITTEE
HEALTH AND OLDER AMERICANS
Question. Doctor, last year the Committee urged NIDR to launch a research and action program for improving the oral health of older Americans. What progress has been made in this effort?
Answer. Following our analysis of data which showed that older people had the most severe oral health problems of any age group, NIDR developed the Research and Action Program for Improving the Oral Health of Older Americans and Other Adults at High Risk. The goals of the program are to eliminate oral diseases that lead to tooth loss, improve dental therapeutics and materials, and reduce barriers to self- and professionally provided care. We are committed to providing as much funding and other resources as possible to the program. This will entail targeting specific projects and encouraging other organizations to increase their emphasis on the oral health of adults. A summary of recent progress follows:
The Assistant Secretary for Health established an Interagency Oral Health Coordinating Committee, which has endorsed the program and defined overall objectives and implementation plans for each Public Health Service Agency. For example, the Centers for Disease Control will work with state and territorial dental directors in disease prevention programs.
We have contracted with a private foundation to develop a
The Institute has issued a Request for Applications for Core Clinical Centers focused on the Research and Action Program; a Broad Agency Announcement inviting applications for clinical and demonstration research among adults; and two Requests for Proposals: 1) concerning reasons for tooth loss, and 2) for collaboration with the Indian Health Service to control periodontal diseases in Native Americans at high risk.
We have initiated plans for a 1991 workshop on oral symptoms as an early sign of osteoporosis.
Question. As you know, the oral health of nursing home patients is very, very poor. In your opinion, what should be done to improve the status of dental and oral health of nursing home patients?
Answer. We have supported several studies to assess risk factors and oral health problems common to nursing home patients. Often these relate to ill-fitting dentures and poor oral hygiene--leading to infections, other oral health problems, and a degree of discomfort that diminishes the quality of life and can add to the debility of the patient. There have been studies indicating that the supervised use of antimicrobial mouth rinses or sprays can be used effectively to control or prevent dental disease in patients unable to carry out regular oral hygiene practices. Provision of dental care services remains problematic in many nursing homes, however, and is not within the province of NIDR.
What the Institute can do is support the dissemination of information to patients, family members, and nursing home staff about appropriate oral hygiene practices. Such activities are included in the goals and objectives of the Research and Action Program.
We have also supported demonstration research projects in nursing home patients and continue to support a number of dental investigators who work with older veterans receiving care at VA Medical Centers and nursing homes. We expect that investigators responding to our Broad Agency Announcement will include research and demonstration projects relevant to the oral health needs of nursing home patients.
Finally, NIDR, the National Institute on Aging, and the Department of Veterans Affairs are working to develop collaborative research projects. Among other activities, this has led to an NIDR-DVA collaborative research center on oral health in aging in Florida and to an expansion of research training on geriatric oral health for dental clinical investigators .
In the long term, it is envisioned that the emphasis placed by the Research and Action Program on the prevention of oral disease problems in the adult population will enable the elderly to face the aging years with much improved oral health status.
HEALTH RISK FROM SILVER FILLINGS
Question. Dr. Loe, I understand that the old notion that the mercury in the silver colored fillings in our teeth might be poisoning us is having yet another resurgence, scaring and confusing people. There was a "60 minutes" CBS TV show that was sympathetic to the view that the silver colored fillings do cause a health risk.
Doctor, what are the facts with regard to the health risk of silver colored fillings? Do you feel that we should, through your research program, be developing alternative filling materials?
Answer. The silver fillings containing mercury are called amalgams. Introduced 150 years ago, amalgam fillings are the most durable and most inexpensive materials for dental restorations and currently make up 75 to 80 percent of all restorations. About 10 years ago, dental investigators demonstrated that mercury vapor is released from fillings during chewing and other activities that abrade the teeth. Since that discovery, NIDR-supported scientists have been investigating the mechanisms of release, the amounts released and absorbed by the body, and the effects of absorbed mercury on cells. Research to date has not proved that mercurycontaining amalgams are harmful to anyone except those rare individuals who are hypersensitive to mercury. There is no scientifically sound evidence linking mercury in amalgams to multiple sclerosis, arthritis, mental disorders, or other diseases.
Nevertheless, NIDR continues to investigate these issues and has formed a Task Force which is working with the scientific community to stimulate population studies about the effects, if any, of amalgams on human health. In addition, the Institute continues to support research to develop new and improved nonmercury-containing materials. Three new materials science centers have been funded to further the effort to find alternative materials or to improve the plastic materials already in use to make them as durable as amalgam.
In March 1991, NIDR was asked by the Assistant Secretary for Health to review the benefits of dental amalgam. That study is part of a larger effort by the Public Health Service to review the