Long-term Evaluation of Surface Treatment on Immediate Dentin Sealing

Objective: To study the long-term effect of different surface treatments on the adhesive layer of immediate dentin sealing (IDS) using microtensile bond strengths (µTBS). The null hypothesis tested was that there is no difference in the bond strength of IDS submitted to different surface treatments. Methods: 24 recently extracted molars were seccioned and the exposed middle dentin was immediately sealed with OptiBond FL (OB). The specimens were stored in distilled water for 7 days. Four different treatmets were applied to adhesive layer: (1) no treatment (NT), (2) silica coating+etching (CJ - CoJet; 30µ SiO) , (3) aluminum oxide air-abrasion (AO, 50µ Al₂O₃), (4) silica coating+no etching (CJNE). Composite onlays were fabricated (Filtek Z250, 3M ESPE) and their intaglio sandblasted and silanated. All the specimens were etched with 37.5% phosphoric acid and the restorations adhesively cemented with OB/RelyX ARC, except for group CJNE in which no etching was performed. The specimens were tested after 24 hours and after artificial aging (20,000 thermal cycles). Specimens were sectioned to obtain sticks with a cross section of 0.8±0.2 mm². All sticks were fractured by tension at a crosshead speed of 1mm/min. The obtained data were submitted to 2-way ANOVA variance analysis followed by Duncan post-hoc test at P<.05. Additional teeth were selected and the treated adhesive layer observed under FESEM and CLSM. Results: (Mean/SD in MPa, PTF=pre-testing failure/spontaneous debonding, and N = number of specimens):

Conclusions: IDS does not require air abrasion or silica coating before final cementation.