Lesions in vitro associated with a Fl-containing amalgam and a stannous fluoride solution

Secondary caries is one of the most important factors leading to replacement of amalgam restorations. This investigation compared the anticariogenic effect of a fluoride-containing amalgam, a stannous fluoride application in the cavity prior to restoration with conventional amalgam, and the combination of the fluoride treatment with the well-recognized technique of cavity varnishing. Class 5 cavities were prepared in the middle third of both buccal and lingual surfaces of 20 extracted premolars. Conventional amalgam was inserted in 10 cavities (control group). Fluoride-containing amalgam was inserted in 10 cavities (second group). The third group received a treatment of 8% SnF2 and the fourth group received the SnF2 and a cavity varnish application before insertion of the conventional amalgam. After 15 weeks in an acid-gel for caries-like lesion formation, the teeth were sectioned longitudinally and examined with polarized light. The results showed that both fluoride-containing amalgam and conventional amalgam with prior treatment of the cavity with the stannous fluoride solution and varnish had an inhibitory effect on the development of artificial cavity wall caries in vitro.