Shear bond resistance and enamel surface comparison after the bonding and debonding of ceramic and metallic brackets.
OBJECTIVE
To evaluate, in vitro, the shear bond strength presented by three brands of polycrystalline ceramic brackets and one brand of metallic bracket; verify the adhesive remnant index (ARI) after the tests, and analyze, through scanning electron microscopy (SEM) the enamel surface topography after debonding, detecting the release of mineral particles.


METHODS
Sixty bovine lower incisors were used. Three ceramic brackets (Allure®, InVu®, and Clarity®) and one metallic bracket (Geneus®) were bonded with Transbond XT®. Kruskal-Wallis's test (significance level set at 5%) was applied to the results of shear bond and ARI. Mann Whitney's test was performed to compare the pairs of brackets in relation to their ARI. Brown-Forsythe's test (significance level set at 5%) was applied to the results of enamel chemical composition. Comparisons between groups were made with Games-Howell's and the Post-hoc tests.


RESULTS
No statistically significant difference was observed in relation to the shear bond strength loads. Clarity® brackets were the most affected in relation to the surface topography and to the release of mineral particles of enamel (calcium ions).


CONCLUSIONS
With regard to the ARI, there was a prevalence of score 4 (40.4%). As for enamel surface topography, the Geneus® bracket was the only one which did not show superficial tissue loss. The InVu® and Clarity® ones showed cohesive fractures in 33.3% and the Allure® in 50%, the latter being the one that presented most fractures during removal.
José Maurício
JM
da Rocha
Marco Abdo
MA
Gravina
Marcio José
MJ
da Silva Campos
Cátia Cardoso Abdo
CC
Quintão
Carlos Nelson
CN
Elias
Robert Willer Farinazzo
RW
Vitral
D000268:Adhesiveness; D000818:Animals; D002118:Calcium / Q000032:analysis; D002417:Cattle; D002516:Ceramics / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry*; D001840:Dental Bonding; D003743:Dental Enamel / Q000737:chemistry / Q000648:ultrastructure*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D004577:Electron Probe Microanalysis; D004868:Equipment Failure; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013052:Spectrometry, X-Ray Emission; D013314:Stress, Mechanical; D013499:Surface Properties
D003722:Dental Alloys; D003764:Dental Materials; D019279:Resin Cements; C477790:Transbond XT; D002118:Calcium
Orthodontic brackets; Scanning electron microscopy; Shear bond strength; Tooth enamel