RESIN-MODIFIED GLASS-IONOMER CEMENTS - FLUORIDE RELEASE AND INFLUENCEON STREPTOCOCCUS-MUTANS GROWTH

The aims of the present study were to measure the fluoride release of 1 glass ionomer cement, 1 cermet cement, 3 resin-modified glass ionome r cements and 1 compomer, and to determine the influence of each mater ial on bacterial growth. Test specimens were eluted in saline for 180 days. Every 2 days, the specimens were transferred into fresh saline a nd the fluoride content of the solution was measured. Furthermore, 48- h, 14-d, 90-d, and 180-d eluates were inoculated with Streptococcus mu tans and bacterial growth was recorded nephelometrically. Fluoride rel ease dropped significantly over time for each material with values bet ween 6.2 (Ketac-Silver) and 29.3 (Photac-Fil) ppm after 48 h to values between 0.6 (Ketac-Silver) and 1.7 (Ketac-Fil, Vitremer) ppm after 18 0 days. Each material reduced bacterial growth at each time of examina tion, but the effect decreased significantly over time with a maximum growth of 71.7% (Ketac-Fil) to 85.6% (Ketac-Silver) after 48 h and 94. 7 (Vitremer) to 99.0% (Ketac-Silver) after 180 days (growth control = 100%). Both Ketac-Silver and Dyract showed a significantly lower inhib iting effect on bacterial growth than the other materials. The tested materials showed a good correlation between fluoride release and influ ence on bacterial growth. However, both effects dropped dramatically o ver the 180-days period.