The importance of dentin collagen fibrils on the marginal sealing of adhesive restorations: An in vitro study

Abstract

Aim: This study is aimed to evaluate the importance of collagen fi brils in the adhesion of diff erent self-etching adhesive materials to dentin. Methods: Sixty Class V restorations were prepared on the buccal and lingual surfaces of 30 recently extracted human premolars, with the cervical margins in dentin and the occlusal margins in enamel. These restorations were distributed to three groups of 20 cavities each based on the employed adhesive system used: Group A: G-Bond (GC, Corporation Tokyo, Japan); Group B: Xeno V (Dentsply Caulk Milford, DE, USA); Group C: Adper Easy One (3M/ESPE). Each group was subdivided according to dentin treatment: Subgroup 1-manufacturer's adhesive protocol and Subgroup 2-Removal of the collagens fi bers (total etch + sodium hypochlorite 5% for 2 min) + adhesive protocol. After the restorations, the teeth were subjected to thermal cycling, washing and scoring according to dye penetration. Dye penetration was evaluated using steriomicroscope. Results: When the dentin microleakage scores were compared in subgroups A1VsA2, B1VsB2 and C1VsC2, then Mann-Whitney test revealed signifi cant diff erences between Subgroup A1 and Subgroup A2 (P < 5%). There was no signifi cant diff erence in Groups B and C. Conclusion: The results revealed that the collagen fi brils are not required for adhesion, and their removal improves the marginal seal of G-Bond, an acetone based dentin bonding system.

Mechanical and Physical Properties of Two Different Resin-based Materials: A Comparative Study

“…This type has been produced with nanofiller technology, which reduces the interstitial spacing of the filler particles and, therefore, provides increased filler loading and better physical and mechanical properties. 9,26,27 The immersion in distilled water was done as test specification to prevent specimen desiccation and allow for composite to postcure if any occurs. The 24 hours storage period before the test was essential for elution of unreacted component from the composite.…”