Recently, the dental filling material amalgam has again been a target of criticism, especially within the mass media. The controversy has been further fueled by the combination of the patients' desire for fillings to match tooth colouring and this latest wave of artificially created fear of the poison mercury. The investigation submitted here is seen as a contribution toward clearing up the issue of any risk. Using flameless atom absorption spectroscopy, blood and urine samples were taken from four test groups and examined for their mercury content. Two of the participating groups tested (dentists and assistants) were actively processing mercury while the other two, one with and one without amalgam fillings, served as control groups. In the daily preparation of amalgam, dental staff working in the dental office were subject to greater exposure to mercury vapours. Their blood readings, therefore, were double those of the control group, while their urine readings were much higher than those for people not working with mercury. The two control groups (with and without amalgam fillings) showed no significant difference in mercury levels, which implies that these slight traces of mercury can be attributed to food and the environment. Although the mercury readings of the dental office personnel were twice as high as that of the control group, there was no threat of mercury poisoning for any of the four groups. The continued use of amalgam fillings in teeth can be recommended without reservation and at no risk to the patient. Particular measures must be taken to guarantee the safety of office staff.

Adolescent↗

PubMed1990

[The marginal accuracy of the fit of fixed adhesive ceramic inlays].

48 extracted human molars were restored with MOD inlays using 3 different ceramic systems: Dicor, Mirage and Vitadur N. For the Dicor system both the direct and indirect manufacturing procedures were used and all the necessary technical and clinical steps were performed. After being subjected to a thermal cycling stress test for 100 days, the teeth were ground sectioned for light microscopic examination. Sintered high-strength ceramic systems (Mirage and Vitadur N) displayed significantly better marginal adaptation than casted glass ceramic. In order to estimate the extent of the outer marginal gap, we measured the defective surface where the adhesive composite had disintegrated. The best possible marginal fit will certainly prolong the longevity of inlay restorations.

Ceramics↗

PubMed1990