Influence of immediate dentin sealing and interim cementation on the adhesion of indirect restorations with dual-polymerizing resin cement.

STATEMENT OF PROBLEM: Dentin surface contamination before the cementation of indirect restorations may impact bonding effectiveness.

PURPOSE: The purpose of this in vitro study was to analyze the influence of immediate dentin sealing (IDS) and interim cementation on the adhesion of indirect restorations with a dual-polymerizing resin cement.

MATERIAL AND METHODS: Composite resin inlays were placed in class V cavities prepared in the buccal and lingual surfaces of 30 extracted human molars with a dual-polymerizing resin cement in 3 different ways (n=10): CG, directly on dentin; PG, after 14 days interim cementation; SG, after IDS and 14 days interim cementation. Buccal restorations were sectioned into sticks and submitted to the microtensile bond strength (μTBS) test. Lingual restorations were submitted to micro-Raman spectroscopy (MRS). Data were analyzed with 1-way ANOVA and the Tukey-Kramer post hoc test (α=.05).

RESULTS: Significantly higher μTBS results were found for SG (35.7 ±8.2 MPa) when compared with CG (23.1 ±7.1 MPa) and PG (17.0 ±6.0 MPa) (P<.05), but no differences were observed between CG and PG. MRS showed that the diffusion zone in SG (3.7 ±0.5 μm) was significantly thicker than that of CG (1.8 ±1.2 μm) or PG (1.5 ±0.3 μm) (P<.05). Additionally, a new interface peak (at approximately 1330 cm-1 ) was found in SG, indicating a chemical interaction.

CONCLUSIONS: The use of IDS before cementation resulted in a chemical interaction at the interface and significantly higher μTBS and diffusion zone thickness values. Interim cementation did not interfere with adhesion quality when compared with the control group.