بررسي تاثير وج هاي هادي نور داخل ترميم در كاهش ريزنشت ميناي لبه لثه اي ترميم هاي كامپازيتي خلفي

Introduction Microleakage of gingival floor in class II composite resin restorations is a major clinical problem. The aim of this study was evaluation of the effects of light conducting intrawedges (LCIW) in decreasing gingival microleakage I millimeter above CET in class II composite resin restorations. Materials and Methods Sixty maxillary first molars were randomly divided into six groups of ten. Proximal slot cavities with gingival floor one millimeter upper to CET were prepared. They were filled with Brilliant composite (A3) by six different methods: A: Unfilled resin (UR) + One bulk placement D: UR+Incremental placement B: UR+Light Conducting Intrawedge(LCIW)+One bulk placement E: UR + LCIW + Incremental placement C: DBA + LCIW + One bulk placement F: DBA+LCIW+Incremental placement An etched and silanated bioglass cylinder (2mm diameter) was used as LCIW. After 2500 times of thermocycling (5°`-55°`), Samples were stained and molded in epoxy resin. Mesiodistal sections were prepared one in central and the other in the most lateral part (buccal or lingual) of gingival floor. Dye penetration was determined using a stereomicroscope. The statistical analysis was done by one way ANOVA and Duncanʹs test. Results The mean dye penetration of central and lateral sections was the least in group C (0.8 & 1 respectively) and then group F (1.2 & 1.3). This shows that because LCIW has been inserted in cavity after curing of 1mm layer in gingival floor in groups E and F, their effect in decreasing the microleakage is less (compared with group C). Conclusion LCIW in one bulk placement of composite resin restorations can minimize the associatd difficulties.