IN VITRO INVESTIGATION OF EFFECT OF THERMOCYCLING ON MICROLEAKAGE IN CLASS V COMPOSITE RESTORATIONS

Purpose: the aim of this study was to evaluate in vitro effect of thermocycling on microleakage of new generation adhesive systems on class v restorations. materials and methods: 150 caries free human molar teeth were used in this study. standardized class v cavities were prepared on buccal surfaces of all teeth and were randomly assigned to 5 groups of each 30. group 1: clearfil s3, group 2: xeno v, group 3: g bond, group 4: optibond all in one, group 5: ibond were applied. restorations and adhesives were applied according to manufacturers’ recommendations and polymerized with led. then the teeth were randomly assigned to two groups of each 15. first group was thermocycled at 5° and 55°c for 10.000 cycles but the second was not. all samples, except 1 mm around of restoration, were coated twice with nail varnish, then were stained 24 hr in 0.5 % methylene blue and washed, then were scored for microleakage of enamel and gingival walls under stereomicroscope. the data were analyzed with kruskal wallis and mann whitney u tests. results: lt was defined that there was statisticallysignificant difference among groups in microleakagescores (p<0.05). in thermocycling applied and nonappliedteeth the highest microleakage was seen inibond group. conclusion as trying to pretend oral conditions with thermocycling in our study, it was defined that thermocycling did not affect any microleakage scores in the present study.