In vitro evaluation of microleakage of a flowable composite in class V restorations

Abstract

The aim of this study was to evaluate microleakage around class V restorations using a flowable composite compared to a hybrid composite. Forty class V cavities were prepared on buccal and lingual surfaces of 20 human teeth, with occlusal and cervical margins at the enamel and cementum/dentin levels, respectively. Specimens were divided into 2 groups with 10 samples each. Group 1: buccal cavities received Paama 2 (conventional bonding agent) + Wave (flowable composite); lingual cavities were restored with Paama 2 + Glacier (hybrid composite). Group 2: buccal cavities received Optibond Solo (self-priming bonding agent) + Wave; lingual cavities were restored with Optibond Solo + Glacier. After being stored in distilled water and finished, the teeth were thermocycled, immersed in a 50% silver nitrate solution and embedded in resin. They were sectioned and the depth of tracer penetration was scored. The results were analyzed using Kruskal-Wallis and Wilcoxon tests. The restorations with flowable composite and those with hybrid composite from the same group showed similar results of microleakage for both occlusal and cervical margins. Optibond Solo improved the sealing of the restorations when compared with Paama 2 (p < 0.01). None of the restorative materials completely sealed the tooth/restoration interface at the cervical margins.

Leakage Pathway of Class V Cavities Restored With Different Flowable Resin Composite Restorations

“…Also, Chimello and others 17 and Estafan and others 18 found no difference in the occlusal or cervical microleakage of cavities restored with flowable or hybrid resin composites.…”

Effect of resin liners on the microleakage of class V dental composite restorations

“…In addition to this, the acid etching technique in enamel provides optimal anchorage, capable of resisting to the contraction forces resulting from the composite resin polymerization. It means that, during the polymerization process, the composite resin shrinks towards the enamel margins, thus forming a gap at the interface between cementum/dentin and the composite 7 , confirming the importance of evaluating the dentin wall.…”

“…Evaluation of microleakage is the most common method to assess the sealing efficiency of a restorative material 2 . Several microleakage studies have demonstrated that it is more difficult to seal the cervical dentin margins 7,24 , so this study was accomplished considering just the dentin substrate to evaluate the microleakage levels. Dentin was defined by Marshall 18 as a vital complex hydrated composite.…”

“…Although many new bonding systems have been developed to promote good adhesion between the composite resin and dental substrates, they could not ensure perfect sealing of the composite resin restoration 24,28 . Of special concern is the seal at the interface between cementum/dentin and the composite resin, because adequate seal is critical at these margins, as demonstrated by other authors 7,24,28 .…”

“…Flowable composites have been indicated as liners 7,11,25,29 . Estafan, et al 11 have confirmed the efficiency of this technique to improve the marginal adaptation of composite restorations.…”