Alzheimer's disease, dental amalgam and mercury.

BACKGROUND: Mercury, or Hg, is a neurotoxin that has been speculated to play a role in the pathogenesis of Alzheimer's disease, or AD. Dental amalgam releases low levels of Hg vapor and is a potential source of Hg for a large segment of the adult population. METHODS: The authors studied 68 subjects with AD and 33 control subjects without AD to determine Hg levels in multiple brain regions at autopsy and to ascertain the subjects' dental amalgam status and history. The subjects were from central Kentucky and Elm Grove, Wis. The authors conducted dental amalgam assessments during the lives of the majority of subjects and in some subjects at the time of autopsy only. The authors also determined three dental amalgam index scores--Event (placement, repair or removal of amalgam), Location and Time In Mouth--in addition to the numbers of and surface area of occlusal amalgam restorations. The authors determined Hg levels in multiple brain regions and performed full neuropathologic evaluations to confirm the normal status of the brain or the presence of AD. RESULTS: The authors found no significant association of AD with the number, surface area or history of having dental amalgam restorations. They also found no statistically significant differences in brain Hg level between subjects with AD and control subjects. CONCLUSIONS: Hg in dental amalgam restorations does not appear to be a neurotoxic factor in the pathogenesis of AD. The authors found that brain Hg levels are not associated with dental amalgam, either from existing amalgam restorations or according to subjects' dental amalgam restoration history. CLINICAL IMPLICATIONS: Dental amalgam restorations, regardless of number, occlusal surface area or time, do not relate to brain Hg levels.

Periodontal status of diabetic and non-diabetic men: effects of smoking, glycemic control, and socioeconomic factors.

Periodontal disease is more prevalent and more severe in diabetic than in non-diabetic individuals but the magnitude of this increase is still being debated. This prospective, cross-sectional study compared the periodontal status of 118 diabetic men and 115 age-matched non-diabetic men. Plaque and gingival indices, bleeding scores, probing depth, loss of attachment, and number of missing teeth were measured in a blinded manner. Smoking status, glycemic control, socioeconomic status, and previous dental care were also assessed. These parameters were significantly higher in diabetic than non-diabetic men: plaque index, P < 0.0001; gingival index, P < 0.0002; bleeding score, P < 0.0001; probing depth, P = 0.0059; loss of attachment, P < 0.0001; and missing teeth, P < 0.005. These parameters were significantly higher in smokers than non-smokers: gingival index, probing depth, and loss of attachment. The duration of diabetes was not significantly related to the periodontal measures. Glycemic control as assessed by fasting plasma glucose and glycohemoglobin values was not significantly correlated to periodontal status. These studies indicate, for this study group, that diabetes significantly affects all measured parameters of periodontal status.

Dental amalgam and cognitive function in older women: findings from the Nun Study.

The authors determined the number and surface area of occlusal dental amalgams in a group of 129 Roman Catholic sisters who were 75 to 102 years of age. Findings from this study of women with relatively homogeneous adult lifestyles and environments suggest that existing amalgams are not associated with lower performance on eight different tests of cognitive function.

New programs for advanced training in dental geriatrics.

The unprecedented increase in the number and percentage of Americans who are older than the age of 65 is presenting the health care system with unique diagnostic, therapeutic, fiscal, and ethical challenges. Chronic disease, complex pharmacotherapeutic regimens, and psychosocial and physical dysfunction are prevalent in this age group. The dental profession is faced not only with an increase in the number and complexity of older patients, but with the fact that growing numbers of older patients are retaining a greater proportion of their natural dentitions for longer periods. To help meet the need for increased professional skill to deal with these issues, the Health Resources and Services Administration of the Department of Health and Human Services is supporting 23 medical school based geriatrics training programs, designed expressly for physicians and dentists. The programs offer a mixture of experiences in: clinical care of the elderly in a variety of settings; design and conduct of research relevant to geriatric and gerontologic issues; enhancement of pedagogical skills; and program administration. Physicians and dentists share many of the training experiences, providing both groups with unique insights into the presentation and management of their patients' problems, and an enriched awareness of each other's contributions to the care of the elderly.

The effect of cigarette smoking on anaerobiosis in the oral cavity.

Nineteen young adult male smokers were compared to 19 adult male nonsmokers to determine if cigarette smoking resulted in any changes to anaerobic bacteria in dental plaque, to intraoral oxidation-reduction potential (Eh) levels, or to intraoral pH. There was no statistical difference between smokers and nonsmokers in the proportion of anaerobic bacteria found in dental plaque. There were no significant differences between smokers and nonsmokers with respect to the resting Eh in the floor of the mouth nor in the Eh in the region of buccal surface of the upper molars. The smoking of one cigarette resulted in a dramatic fall in Eh in both intraoral regions and this occurred in all subjects, both smokers and nonsmokers. The magnitude of this fall in Eh was similar in both groups. There were also uniform increases in pH, but these pH changes were much smaller in magnitude.