2017 Volume 60 Issue 6 Pages 289-298
Purpose: The influence of different etching modes (phosphoric acid [PA] or self-etch [SE] adhesive) on the adaptation of resin-based pit and fissure sealant to the enamel and dentin was examined by optical coherence tomography (OCT).
Methods: Bovine teeth were used as substitutes for human teeth, and standardized preparations were made. Six specimens were used for each test group to evaluate the adaptation of the material. One etching-mode group of the specimens was treated with 35% phosphoric acid (PA) for 15 s and then rinsed with a water spray for 10 s. The specimens in the second etching-mode group were treated with self-etch (SE) adhesive according to the manufacturer’s instructions. Subsequently, the sealant was inserted into the cavity and light-irradiated for 20 s. Specimens were stored in distilled water at 37°C for 24 h and then subjected to 50,000 thermocycles (TCs) between 5°C and 60°C, with a dwell time of 30 s. With the use of OCT, the peak intensity (dB) at selected locations on the sealant surfaces was measured in A-scan mode, and the B-scan images were observed. Data were subjected to two-way repeated-measures analysis of variance and the Tukey-Kramer test (α=0.05).
Results: Representative B-scan images of the PA-treated enamel specimens showed a weak and narrow signal from the sealant-enamel interface, with no backscattered intensity before the TCs, and with slight changes to the OCT images after 50,000 TCs. For the SE group of enamel specimens, visible signals from the sealant surface were observed, with backscattered light considerably greater than the noise level. There were significant differences in the peak signal intensity at the sealant-tooth interface before and after the TCs for the PA-treated enamel and dentin specimens. Conversely, there were no significant differences for both substrates of the SE test groups.
Conclusion: A comparison of PA etching and SE adhesive for use with pit and fissure sealants revealed that employing a universal SE adhesive might promote effective adaptation of the material to both the enamel and the dentin.
