Effect of Three Restorative Techniques on Gingival Microleakage of Silorane-based Composite in Class Restorations

Background and Microleakage occurs in posterior composite restorations due to polymerization shrinkage. In recent years low shrinkage silorane-based composites have been introduced to reduce microleakage. The aim of this study was to evaluate the effect of three different restoration techniques on gingival microleakage of a silorane-based composite in class II restorations. In this experimental study, class II cavities were prepared in mesial and distal surfaces in 40 sound human premolars. The gingival floor was located 1.0mm below the CEJ. Dimension of cavities were 3mm buccolingually and 1.5mm in axial depth of gingival floor. The specimens were randomly divided into 4 groups. Group1 (control) was restored incrementally with silorane based composite (Filtek P90). Group 2, 3 and 4 were restored using glass fiber, flowable composite and resin-modified glass ionomer (RMGI) liners, respectively. After finishing and polishing of the restorations and thermo-cycling, the specimens were immersed in 2% Basic Fuschin for one week. Microleakage was determined under a stereomicroscope (40X). Data was statistically analyzed by Kruskal-Wallis test (P<0.05). The statistical analysis revealed no significant difference in microleakage among study groups (P=0.243). The sealing ability of glass fiber inserts, flowable composite and resin modified glass ionomer liners is not better than that of the silorane-based composite alone in gingival margins of Class II restorations.