Performance of two laser motion modes versus conventional orthodontic ceramic brackets debonding technique on enamel surface topography

Abstract

The risk of enamel deterioration that frequently coexists with debonding of orthodontic teeth brackets elevates the mandate for finding an optimum approach for debonding them without harmful effects. This in-vitro study is intended to compare the effects of two different laser modes (scanning and circular) and a conventional method on the enamel surface after debonding orthodontic brackets. 66 extracted premolars were assigned into 3 groups. After that, light-cure composite resin was used to attach the ceramic brackets to the teeth. Amongst the test groups, Group I: specimens that were debonded using conventional debonding using pliers; Group 2: specimens that were debonded using Er, Cr: YSGG laser applications using the circular motion method; and Group 3: specimens that were debonded using Er, Cr: YSGG laser applications using the scanning motion method. Adhesive Remnant Index (ARI) assessment, intra-pulpal temperature increase, enamel surface roughness after polishing, and assessment of the microstructure of enamel were carried out with scanning electron microscopy. The gathered information was examined statistically. The conventional debonding method had a significantly higher proportion of adhesive remnant index (ARI) scores of 2 and 3 in comparison to the circular (p < .004) and scanning laser groups (p < .001). There was no significant difference in ARI scores between the circular and scanning laser groups (p > .05). Moreover, the circular and scanning laser debonding methods resulted in a significantly higher proportion of Enamel Surface Roughness (ESR) scores of 0 and a lower proportion of ESR scores of 3 compared to the conventional technique group (p < .001). However, there was no significant difference in ESR scores between the circular and scanning laser methods (p = .945). Lastly, the average intra-pulpal temperature was significantly higher in the circular laser group (1.9 ± 0.5 ) compared to the scanning laser group (0.9 ± 0.2) with p < .001. Er, Cr: YSGG laser irradiation is a tool that shows promise for debonding ceramic brackets with minimal harm to the enamel surface. The scanning laser technique is more desirable due to the lower intra-pulpal temperature increase.

Keywords: Ceramic brackets; Debonding; Enamel; Laser; Surface characterization; Topography.