Which is the best adhesive system for primary tooth enamel? A systematic review and network meta-analysis of bond strength data.

Purpose: Evaluate the bond strength performance of the different types of adhesive systems to the primary tooth enamel. Methods: This study was registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/YURB4). A two-stage literature search was conducted by two independent reviewers on PubMed, Embase, Web of Science, Scopus, and gray literature to identify in vitro studies evaluating the bond strength of different adhesive systems to primary tooth enamel. The risk of bias was evaluated with the QUIN tool. A Bayesian network meta-analysis was conducted to evaluate the bond strength at 24 h. Results: The final sample was composed of 14 articles. The 2-bottle universal adhesive system with phosphoric acid etching (PAE) was statistically similar to the 3-step etch-and-rinse (E&R). In addition, self-etch and etch-and-rinse adhesives with the same number of steps had similar performances. In the ranking, 3-step E&R had the highest probability of being ranked the best adhesive, while 1-step self-etch without PAE had the lowest. All studies had a low risk of bias. Conclusion: 2-bottle universal adhesive systems with PAE can probably provide similar bond strength to primary tooth enamel compared to 3-Step E&R. In addition, the similar performance of some of the tested adhesive systems indicates the possibility to reduce clinical steps.