IN-VIVO CARIOSTATIC EFFECT OF RESIN MODIFIED GLASS-IONOMER CEMENT ANDAMALGAM ON DENTIN

Fluoride-releasing materials have been reported to be bactericidal in vitro. This may be of benefit to modem dentistry, which is directed to the preservation of tooth tissue during restorative treatment. Little is known about in vivo effects. The aim is to investigate the influen ce of a resin-modified glass ionomer cement (RM-CIC) on carious dentin e that remains under restorations, compared to amalgam. Using a split mouth design, 40 molar pairs in 40 patients (mean age 14.9 years) were selected, based on clinically and radiographically diagnosed occlusal dentine caries. Under aseptic conditions, the enamel was removed and the carious dentine was sampled just beneath the dentino-enamel juncti on using a round bur. Without further removal of carious dentine, the molars of a pair were alternately restored with RM-GIC or amalgam. The colour and the consistency of the carious dentine were assessed. The samples were processed for microbiological determination of total viab le counts (TVC), mutans streptococci (MS), and lactobacilli (LB). Afte r 6 months the molars were reopened, similarly sampled and evaluated, and then permanently restored after complete caries removal. For both materials a substantial decrease in the numbers of TVC, MS and LB was found after the 6-month period. Also a positive effect was observed on the colour and the consistency of the remaining carious dentine, whic h was comparable for the two materials. RM-GIC showed a significantly larger decrease in counts of MS and LB than amalgam, but not for TVC. Since in only few cavities the number of bacteria decreased under the level of detection, it is still considered essential to remove all car ious dentine during restorative treatment.