Orthodontic bracket bonding techniques and adhesion failures: A systematic review and meta-analysis

BACKGROUND: This systematic review compared the bonding failures of orthodontic brackets bonded by indirect or direct techniques. Data sources: The searched databases were Cochrane Library, LILACS, BBO, PubMed, Scopus, Web of Science. MATERIAL AND METHODS: A search for randomized clinical trials comparing the two techniques was carried out to answer the research question: When considering orthodontic bracket bonding on permanent teeth, does the indirect technique reduce the number of bonding failures compared to the direct one over time? The quality of the included papers was assessed with Cochrane risk of bias tool and the quality of evidence with GRADE. RESULTS: From 3096 articles identified, seven were included in the systematic review (five at unclear; two at low risk of bias). Meta-analysis was carried out according to the follow-up periods (0-6 months and 12-15 months). RESULTS: In the first period, bonding techniques were similar with regard to adhesion failures (RR = 0.59; 95% CI 0.10-3.62; p = 0.00001; I2 = 92%); in the 12-to-15-month period, the direct bonding technique proved to be superior (RR = 1.44; 95% CI 1.05 - 1.99; p = 0.41; I2 = 0%). The quality of evidence was classified as low for the 0-6 months follow-up and high for the 12 months. CONCLUSIONS: Based on the absence of heterogeneity and the high quality of evidence, it is concluded that the direct bracket bonding technique has a lower failure rate than the indirect technique in the long term (12-15 months). Key words:Orthodontic brackets, fixed orthodontics, systematic review.