Fotopolimerizar ou não o adesivo na cimentação de restaurações indiretas

Abstract

Objectives: This study aimed to evaluate the effect of adhesive photopolymerization, the impact of Monowave and Poliwave photopolymerization devices, and assess the effect of Poliwave photopolymerization device's wavelength on ceramic laminate cementation. Materials and Methods: Three hundred and twenty-two sound bovine teeth were used, distributed across three ceramic laminate cementation protocols with photoactivated resin cements. Specimens were randomly allocated according to the protocols: 1) photopolymerized adhesive: Ambar universal (FGM); Tetric N Bond

universal (Ivoclar Vivadent); Scotchbond universal Plus (3M ESPE), and non- photopolymerized adhesives. 2) photopolymerization devices: a) Bluephase N (Ivoclar

Vivadent), b) Raddi Cal (SDI). 3) Wavelength of a Poliwave photopolymerization device. Corresponding commercial cements were used, photopolymerizable and for ceramic laminate cementation, with Vita Mark II ceramic (VITA Zahnfabrik). After cementation according to manufacturer instructions, specimens were stored in distilled water at 37°C for 24 hours, then longitudinally sectioned to obtain ceramic-enamel specimens (0.8 mm^2). For bond strength (μTBS), specimens were tested under tension at 0.5 mm/min immediately (IM) and after 10,000 thermal cycles (TC), n=8; for in-situ degree of conversion (DC), specimens were analyzed using micro-Raman spectroscopy with a red laser (638.8 nm) for mapping (M) and a 785 nm laser. Confocal microscopy analysis (CM) (n=3) involved adding rhodamine to the adhesive and immersion in fluorescein, following the same procedures used for BS. Integrating sphere spectroscopy was used to evaluate light passage through ceramic laminates. Data were analyzed per protocol, with statistical significance set at 5%. Results: Protocol 1 showed statistical differences in bond strength (μTBS) among adhesives ABU, TBU, and SBUP, but not among photopolymerization strategies. Variations were observed in adhesive degree of conversion and changes in functional groups observed in mapping. In Protocol 2, BS between Poliwave and Monowave photopolymerizers showed immediate statistical differences in ABU adhesive. For GC group, ABU showed statistical difference (p < 0.05). No differences were observed for SBUP in BS or GC. Spectrophotometer analysis revealed differences in the percentage of each wavelength for each device used. Regarding transmitted irradiance, mean values were calculated for violet, blue, and total wavelength ranges. In Bluephase, irradiance ranged from 54.34 to 1180.01 mW/cm^2, while in Raddi, it ranged from 7 to 918.66

mW/cm^2. Protocol 3 found no differences in μTBS among Poliwave photopolymerizer wavelengths. Conclusion: Photopolymerizing or not the adhesive during ceramic laminate cementation did not demonstrate an impact on the adhesive properties of these restorations. The choice between Poliwave and Monowave photopolymerizers may influence the efficacy of ceramic laminate cementation, depending on the materials used. The Poliwave device's wavelengths (460nm - 410nm) did not influence ceramic laminate cementation on enamel.