[Varnishes and adhesives in the seal of silver amalgam restorations]

The object of this paper is to evaluate the marginal filtration occurring between restoration/teeth in cavities filled with silver alloy when using different cavity varnish and adhesives. In 50 teeth removed as a result of decay, cavities were prepaired on vestibular faces and were divided into 5 equal groups: Group A: with no caviti varnish; Group B: two coats of a linkin agent (Scotch Bond 3M); Group C: an amalgam liner base (Voco); Group D; two coats of copal varnish: Group E: an amalgam bond base (Carl San Remo, Germany). All groups were filled with a silver alloy. The teeth were inmersed in a fuchsin solution at different temperatures (17.37 degrees C and 50 degrees C) for 20 minutes. Longitudinal cuts were made for visualization under a stereoscopic magnifying glass. Each group was observed by five odontologists and was classified according to four categories: Grade I: no filtration: Grade II: less than 1/3 wall filtration; Grade III: more than 1/3 wall filtration; Grade IV: filtration in walls and floor. Teeth with pulp filtration were discarded. Total and percentage values were determined for each analysed group. The results revealed that: Group A: 100% of samples corresponds to Grade IV. Group B: 40% of sample falls within Grade II while the rest corresponds to the highest grade. Group C: 30% belongs to Grade II, 60% to Grade III and the remaining 10% to Grade IV; Group D: 30% falls within Grade I, while the remaining 20% and 50% correspond to Grades III and IV, respectively. Group E: 50% for Grade I and the rest in Grade II.(ABSTRACT TRUNCATED AT 250 WORDS)