Comparison of flash-free and conventional bonding systems: A systematic review and meta-analysis

Objectives: To review the literature systematically to compare the performance of adhesive precoated flash-free bonding systems with conventional adhesive precoated (APC) and operator -coated (OPC) bonding systems. Materials and Methods: PubMed, Cochrane Library, Web of Science, and Embase were searched for potential eligible studies. Study selection and data collection were conducted independently. Statistical analysis was performed by Review Manager 5.3. The Cochran Q test was used to test heterogeneity in the included studies. Risk of bias was evaluated using Cochrane RoB 2.0 tool for randomized controlled trials. Results: Six studies were included and the overall risk-of-bias judgment was low risk of bias to some concerns. The results of the meta-analyses showed that flash-free required significantly less bonding time than APC (mean difference [MD]:-1.56; 95% confidence intervals [CIs]:-2.56 to-0.56), and no significant differences were found in bond failure rates (risk ratio [RR]: 1.54; 95% Cis: 0.27 to 8.89) and adhesive remnant index (ARI) (MD:-0.50; 95% CIs:-1.14 to 0.14) between them. Qualitative analysis showed that flash-free might have a positive effect on enamel demineralization compared to APC but the quantity of plaque did not differ between them. Conclusions: The flash-free bonding system significantly reduced bonding time and it had comparable bond failure rates with APC. So far, there is not enough evidence to support its positive effect on reducing enamel demineralization and the pathogenic bacteria around brackets. In summary, flash-free might be a better choice for clinical bracket bonding. (Angle Orthod. 2022;92:691-699.)