CONCLUSIONS:
Many studies were imperfect in design. Those considered to be the most appropriate for analysis were too limited to undertake a formal statistical exploration. Therefore there remains a need for definitive randomised controlled trials of restoration longevity, of sound design and adequate power, employing standardised assessments and appropriate methods of analysis.
It was the aim of this investigation to treat 20 volunteers with maximally 5 amalgam fillings by the same comprehensive protocol in which all removals with (n = 8) and without (n = 12) rubber dam had been performed within a few months. Nine amalgam-related parameters indicated a close matching of both groups before removal. In the group without rubber dam, mercury (Hg) levels in plasma increased significantly above preremoval values at days 1 and 3 after removal; they decreased significantly below preremoval values at day 30 in the rubber-dam group and at day 100 in both groups. Excretion rates did not increase significantly in either group, but decreased significantly at day 100 in the protected group. Peak plasma-Hg was 0.6 ng/mL on average at day one and decreased with halftimes of 3 and 43 d in subjects protected by rubber dam. The results indicated that concentrations of total mercury in plasma responded rapidly to changes in the amalgam status and reflected the actual absorption most reliably. Notably, plasma-Hg levels were sensitive enough to detect a transient attenuation of the additional exposure by using rubber dam during the removal of only a few fillings. However, being small in magnitude and lasting 100 d at best, the rubber-dam effect had minor toxicological relevance.
QUESTION:
One of my pregnant patients, a dental hygienist, uses mercury in her workplace, but appears to have no symptoms of mercury toxicity. She has heard that mercury might affect her fetus. What should I recommend to her? What is a safe level of mercury in the air for pregnant women?
ANSWER:
Testing for levels of mercury in whole blood and, preferably, urine is useful for confirming exposure. Currently, mercury vapour concentrations greater than 0.01 mg/m3 are considered unsafe. Also, women of childbearing age should avoid contact with mercury salts in the workplace.
Toxic metals like lead, manganese, copper and cadmium damage neurons and deregulate neurotransmitters like serotonin and dopamine (which are essential to normal impulse control and learning). Earlier studies show that — controlling for socio‐economic and demographic factors — environmental pollution with lead is a highly significant risk factor in predicting higher rates of crime, attention deficit disorder or hyperactivity, and learning disabilities. Exposure and uptake of lead has been associated with industrial pollution, leaded paint and plumbing systems in old housing, lead residues in soil, dietary habits (such as shortages of calcium and iron), and demographic factors (such as poverty, stress, and minority ethnicity). We report here on an additional “risk co‐factor” making lead and other toxic metals in the environment more dangerous to local residents: the use of silicofluorides as agents in water treatment. The two chemicals in question — fluosilicic acid and sodium silicofluoride — are toxins that, despite claims to the contrary, do not dissociate completely and change water chemistry when used under normal water treatment practices. As a result, water treatment with siliconfluorides apparently functions to increase the cellular uptake of lead. Data from lead screening of over 280,000 children in Massachusetts indicates that silicofluoride usage is associated with significant increases in average lead in children’s blood as well as percentage of children with blood lead in excess of 10μg/dL. Consistent with the hypothesized role of silicofluorides as enhancing uptake of lead whatever the source of exposure, children are especially at risk for higher blood lead in those communities with more old housing or lead in excess of 15 ppb in first draw water samples where silicofluorides are also in use. Preliminary findings from county‐level data in Georgia confirm that silicofluoride usage is associated with higher levels of lead in children’s blood. In both Massachusetts and Georgia, moreover, behaviors associated with lead nurotoxicity are more frequent in communities using silicofluorides than in comparable localities that do not use these chemicals. Because there has been insufficient animal or human testing of silicofluoride treated water, further study of the effect of silicofluorides is needed to clarify the extent to which these chemicals are risk co‐factors for lead uptake and the hazardous effects it produces.
Scores on the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), the Million Clinical Multiaxial Inventory-II (MCM-II), and Symptom Check List – 90 (SCL-90) were compared before dental amalgam removal of eight schizophrenia patients to scores six months after amalgam removal. Significant improvement was found in forty-one of the sixty-one component scales of the MMPI-2 and twelve of the twenty subscales including schizophrenia, hysteria, paranoia, and anger. Sixteen of the twenty-five diagnostic scales improved significantly in the MCMI-II including schizoid, anxiety disorders, thought disorders, and bipolar symptoms. Four of nine dimensions improved significantly in the SCL-90 including depression, psychoticism, and obsessive-compulsiive. Because dental amalgam mercury can enter the brain and affect neurotransmitters, the authors hypothesize that removal of the mercury-laden fillings may have contributed to the improved mental health.
Laboratory investigations have often used aluminofluoride complexes for stimulation of various guanine nucleotide binding proteins. These complexes form spontaneously in aqueous solutions containing fluoride and traces of aluminum and appear to act as phosphate analogs. In view of the ubiquity of phosphate in cell metabolism and together with the dramatic increase in the amount of reactive aluminum now found in ecosystems, aluminofluoride complexes represent a strong potential danger for living organisms including humans. Although the possibility of pathophysiological consequences of their long-term action are not yet fully recognized, the pharmacological and toxicological effects of aluminofluoride complexes on animal and human cells, tissues, and organs are identified and summarized in this review.
STATEMENT OF PROBLEM:
Previous studies have identified focal areas of alveolar tenderness, elevated mucosal temperature, radiographic abnormality, and increased radioisotope uptake or “hot spots” within the quadrant of pain in most patients with chronic, idiopathic facial pain (phantom pain, atypical facial neuralgia, and atypical facial pain).
PURPOSE:
This retrospective investigation radiographically and microscopically evaluated intramedullary bone in a certain subset of patients with histories of endodontics, extraction, and fixed partial denture placement in an area of “idiopathic” pain.
MATERIAL AND METHODS:
Patients from 12 of the United States were identified through tissue samples, histories, and radiographs submitted to a national biopsy service. Imaging tests, coagulation tests, and microscopic features were reviewed. Of 38 consecutive idiopathic facial pain patients, 32 were women.
RESULTS:
Approximately 90% of subpontic bone demonstrated either ischemic osteonecrosis (68%), chronic osteomyelitis (21%), or a combination (11%). More than 84% of the patients had abnormal radiographic changes in subpontic bone, and 5 of 9 (56%) patients who underwent radioisotope bone scan revealed hot spots in the region. Of the 14 patients who had laboratory testing for coagulation disorders, 71% were positive for thrombophilia, hypofibrinolysis, or both (normal: 2% to 7%). Ten pain-free patients with abnormal subpontic bone on radiographs were also reviewed.
CONCLUSIONS:
Intraosseous ischemia and chronic inflammation were suggested as a pathoetiologic mechanism for at least some patients with atypical facial pain. These conditions were also offered as an explanation for poor healing of extraction sockets and positive radioisotope scans.
Rosacea is a chronic disorder affecting the facial convexities, characterized by frequent flushing, persistent erythema, and telangiectases. During episodes of inflammation, additional features are swelling, papules, and pustules. The exact etiology of this dermatitis is unknown, and theories abound. Infectious foci, especially dental foci, seem to be rarely associated with the onset and progression of this disease. Dermatologic treatments are determined by the severity of the disease. But eradication of infectious foci, and in this case eradication of dental foci, may generate a significant improvement and may lead to a recovery.
The findings presented here suggest that mercury poisoning from dental amalgams may play a role in the etiology of oral health disorders in multiple sclerosis (MS) patients. Comparsions between MS subjects with dental amalgams and a control group of MS subjects without amalgams found significantly fewer oral cavity symptoms per subject in the amalgam-removal group during twelve months. They had fewer symptoms of metallic taste, foul breath, grinding teeth, and loss of taste. MS subjects with amalgam removal had significantly higher counts of total T-lymphocytes, T-8 suppressor cells, and a lower T-4 helper to T-8 suppressor ratio. The MS amalgam group had significantly lower levels of IgG, and the female MS amalgam subjects had significantly lower levels of IgM. The hair mercury levels of MS patients were significantly higher when compared to a control group of non-MS subjects.
RESULTS:
Of 19 patients with OLL adjacent to amalgam fillings, 15 (78.9%) were sensitized to inorganic mercury (INM), significantly more than those with OLL not adjacent to amalgam, other oral diseases or complaints, and the control group. In 5 of 15 (33.3%) of the patients with OLL, a positive patch test to INM was observed only at D10 or D17. Amalgam was removed in 18 patients with OLL (sensitization to INM: 15), and in 11 patients with OLP (sensitization to INM: 2). After removal, the lesions of 13 of 15 of the INM-sensitized patients with OLL (86. 7%) and 2 with OLP healed or improved significantly, but this was not observed with the INM negative patients. Frequency of sensitization to gold sodium thiosulfate (GST) and palladium chloride 1% pet (PDC) was high in all groups. This was partly because readings were performed late. Lesions of 2 patients with allergic contact stomatitis caused by gold and 1 caused by palladium healed completely after removal of these restorations. Histologically, lichenoid changes were observed in 14 of 36 biopsy specimens of positive patch tests from INM (9/21), GST (2/10), and PDC (3/5) in all patient groups, mainly in persistent patch tests at D10 or D17. This was not observed in 12 biopsy specimens taken from persistent patch tests from other substances, including nickel sulfate.
CONCLUSION:
Our results suggest that sensitization to mercury is an important cause of OLL, whether all lesions or only a part of them are adjacent to amalgam fillings. Sensitization to GST may reflect true gold allergy and should be considered as a cause of oral diseases in some patients. Sensitization to PDC is frequent but has yet only little clinical relevance. Patch tests may be positive only at D10 or D17. This suggests the importance of additional readings of GST, PDC, and mercury salts at this time.