Effectiveness of All-in-one Adhesive Systems Tested by Thermocycling Following Short and Long-term Water Storage

Purpose: To evaluate and compare the marginal integrity of in vitro Class V restorations made with all-in-one adhesive systems by thermocycling after different periods of water storage, to provide an analysis of static and quasi-dynamic deterioration in water. Materials and Methods: Standardized Class V cavities (17 groups, 8 specimens each) were prepared in extracted human caries-free anterior teeth. The cavities were filled using 14 all-in-one adhesive systems/composite resin combinations in addition to the multi-bottle adhesive systems Syntac and OptiBond FL (etch-and-rinse technique) and Clearfil SE Bond (self-etching) as controls. The samples were thermocycled after water storage for 21 days, after 1 year and again after 3 years (2000 cycles between 5 and 55°C) and replicas were made before and after each thermocycling treatment (TC) for quantitative marginal analysis in the SEM. Results: In dentin, marginal adaptation showed no significant differences between all groups after the first TC. After one year of water storage and a second TC, the results for Prompt L-Pop (1999), Adper Prompt L-Pop/Tetric Ceram, and One-up Bond F Plus showed a statistically significant decrease of margin quality 1 (MQ1) score compared to the reference groups. When the all-in-one adhesives G-Bond, AQ-Bond, Hybrid Bond, and One-up Bond F Plus were used, the enamel margins of restorations showed lower percentages of "continuous margins" (p 0.05) after 1 year of water storage and TC. Of the materials tested after 3 years of water storage and TC, only AQ Bond had a significantly lower MQ1 score. Conclusion: While all materials exhibited deterioration in the MQ1 quality score, the rate of deterioration varied, and the results show that different materials have different deterioration rates after initial vs long-term water storage. The deterioration along margins in dentin was not as extensive as predicted from other studies; however, the results from the enamel margins show that one-bottle all-in-one adhesives seem to be significantly affected by water storage. The results of this study suggest that the all-in-one adhesive group members perform very differently from each other: thus, data need to be explored further at the level of each different adhesive product. Keywords: marginal quality evaluation, in vitro Class V restorations, adhesive system effectiveness