Analytical method to estimate resin cement diffusion into dentin

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.