Methods for Aging Dentin-Bonded Interfaces: A Systematic Review and Meta-Analysis

Objectives: Many methods for simulating the aging of dentin-bond composites are used in dentistry, but there is a gap in which methods are actually capable of affecting bond strength (BS). This systematic review aimed to search the different methods and protocols available for accelerated aging simulation and evaluate them by its degradation effect on resin-dentin interface measured by decreasing BS.
Methods: PubMed, Scopus, and Isi Web of Science databases were analyzed and a search strategy was conducted according the following terms: (aging*) AND (material* OR adhes*) AND (dentin*) AND (bond strength*). Only in vitro and in situ studies investigating (micro)tensile or (micro)shear bond strength to artificially aged human dentin-bonded to composites were selected. Studies not written in English or that only static aging was performed (storage in water or artificial saliva) were excluded. For meta-analysis aged groups were compared to non-aged bonded dentin interface.
Results: The search retrieved 11,001 eligible studies. After deduplication, 8,003 records were examined by the titles/abstracts; 7,806 studies were excluded and 197 articles were assessed for full-text reading. In total, 133 articles met inclusion criteria and were included in the analysis. Thermal cycling was the most found method for accelerated aging and had significative effect on decreasing of BS when used with more than 3.1 K cycles. Mechanical and thermomechanical cycling, pulpal pressure, NaOCl storage, thermal cycling + static storage and in situ aging using cariogenic challenge were able to promote BS decreasing. Enzyme storage was only able to decrease BS in periods of at least 3 months. Cariogenic challenge and pH cycling in vitro protocols were not able to promote the decrease of BS.
Conclusions: Different methods of accelerated aging are available, but to be able to promote degradation effect on resin-dentin interface some parameters such as aging time, number of cycles and storage conditions should be considered.