Effect of timing of dentin sealing and provisional restoration method on bond strength of composite resin to dentin

Abstract

The purpose of this study was to evaluate the effect of timing of dentin sealing and provisional restoration methods on the bond strength of composite resin to dentin. Flat dentin surfaces were prepared and the teeth were divided into three groups: control, resinrestoration with immediate dentin sealing (IDS), and resin restoration with delayed dentin sealing (DDS). For the control group, a dentin surface was bonded by using dual-curing dentin adhesive (Excite DSC) and restored with resin immediately. For the IDS groups, a dentin was sealed with OptiBond FL (OB) or Hybrid Coat (HC), and it was restored with following 3 provisional restoration methods: SQ/PQ/CQ {SQ, water-soluble separator (SEP) + provisional resin; PQ, petroleum jelly + provisional resin; CQ, temporary cement (Cavitec) + provisional resin}. For the DDS groups, a dentin was temporized with 2 provisional restoration methods: Q/CQ (Q, provisional resin only) without dentin sealing. After a week, the provisional restoration was removed and cleaned. The treated dentin surface was bonded using Excite DSC and restored with resin, followed by microtensile bond strength (μTBS) tests. The μTBS of control and the IDS-OB groups were not significantly different (P>0.05). The DDS groups presented lower μTBS than control and the IDS-OB groups (P 0.05). However, using CQ significantly lower the μTBS than using Q in the DDS groups (P<0.05). IDS with a etch-and-rinse type dentin bonding agent improved the bond strength. The use of ZOE-containing cement on the unsealed dentin surface decreased the μTBS.