Recycling Debonded Metal Orthodontic Brackets - A Comprehensive Review and Meta-Analysis

Abstract

AIM: This work provides orthodontic practitioners with an updated literature review and meta-analysis on the practicality of reusing debonded metal orthodontic brackets. 
METHODS: An electronic search from January 1989 to June 2017 on MEDLINE-PubMed and EBSCOhost Research Databases yielded 63 studies after removing duplicates. Following initial screening, 47 potentially relevant articles were identified. Detailed scrutiny led to the exclusion of 19 studies. The remaining 19 studies were divided into two groups: Group I (same bracket brand and bonding agent) and Group II (different bracket brand and bonding agents). Meta-analysis and sensitivity tests were conducted using RevMan Analysis in Review Manager (version 5.3). 
RESULTS: The mean shear bond strength (SBS) for debonding a new bracket was 10.16 MPa. Five chairside recycling methods were compared: erbium laser, aluminum oxide sandblasting, high-speed grinding, slow-speed grinding, and direct flaming. Average reductions in SBS were 0.65 MPa, 0.89 MPa, 2.82 MPa, 3.49 MPa, and 3.93 MPa, respectively. 
CONCLUSION: Erbium laser recycling is highly efficient, though cost-prohibitive. Chairside aluminum oxide sandblasting with a microetcher offers a cost-effective alternative with comparable SBS. High-speed grinding surpasses slow-speed grinding, but both exhibit less favorable rebonding strength than sandblasting. Direct flaming yields the lowest SBS. Chairside sandblasting emerges as the most practical and economical method for recycling debonded metal orthodontic brackets.