An in vitro study into the effect of a bacterial artificial caries system on the enamel adjacent to composite and amalgam restorations.

A microbial artificial caries system was used to produce caries-like lesions adjacent to amalgam and composite restorations. Polarised microscopy allowed measurement of outer and wall lesions depths. Comparison was made of the depths found in relation to the restorative materials, margin finishing procedures (composite group), varnish application (amalgam group) and thermal stressing. It was found that differences were detectable between the different restorative materials and the type of margin finishing procedure used in the composite group. Varnish application and thermal stressing had little effect. Some comparison is made between this microbial technique, other artificial caries techniques, and other methods of assessing marginal leakage.