Comparative assessment of different recycling methods of orthodontic brackets for clinical use.

Comparative assessment of different recycling methods of orthodontic brackets for clinical use.

Minerva Stomatol. 2017 Mar 01;:

Authors: de Oliveira Correia AM, de Souza Matos F, Pilli Jóias R, de Mello Rode S, Cesar PF, Paranhos LR

Abstract
BACKGROUND: This study aimed to assess bond strength of the resin/bracket interface, under in vitro shear stress, of metal brackets recycled by different clinical protocols.
METHODS: sixty stainless steel orthodontic brackets were bonded on acrylic resin. The Transbond XTTM resin was applied at the base of the bracket aided by a matrix, obtaining 1 mm of thickness, and photoactivated with a LED device (40s; 500 mW/cm2). Samples were randomly divided into four groups (n=15) according to the reconditioning/recycling protocol: AO - aluminum oxide / 90 μm; HA60 - hydrofluoric acid 60s; HA120 - hydrofluoric acid 120s; HA60S - hydrofluoric acid 60s + silane. After recycling, the resin was applied at the base of the bracket for shear testing in a universal testing machine (0.5 mm/min). After reconditioning/recycling, the surfaces were analyzed by Scanning Electron Microscopy. Data obtained after the shear test were subjected to ANOVA and Tukey's test (p<0.05).
RESULTS: The AO group presented higher values of shear bond strength compared to the other reconditioning/recycling protocols (p<0.05). The HA120 and HA60S groups presented statistically similar results, but HA120 presented strength below the recommended limit.
CONCLUSIONS: The recycling technique by aluminum oxide sandblasting was more effective for reconditioning orthodontic brackets when compared to the other protocols. The reconditioning technique with 10% hydrofluoric acid followed by the application of silane bonding agent may be used as an alternative protocol.

PMID: 28252272 [PubMed - as supplied by publisher]

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