Effect of different bonding protocols on degree of monomer conversion and bond strength between orthodontic brackets and enamel
Sena, Lorena Marques Ferreira de; Barbosa, Helga Adachi Medeiros; Caldas, Sergei Godeiro Fernandes Rabelo; Ozcan, Mutlu; Souza, Rodrigo Othávio de Assunção e.
Braz. oral res. (Online)
; 32: e58, 2018. tab, graf
Artículo
en Inglés
| LILACS | ID: biblio-952156
Abstract The objective of the present study was to evaluate the effect of different surface treatments and polymerization protocols on the bond strength of brackets to enamel, and the degree of conversion of the bonding agents. 120 bovine crowns were embedded in acrylic resin blocks and sanded. Next, the blocks were randomly assigned into 12 groups. Metal brackets were bonded to enamel according to the "surface treatment" factor (A Phosphoric Acid; ATxt Phosphoric Acid + Transbond XT Primer®; Tse Transbond Plus Self Etching Primer®; and SBU Scotchbond Universal®) and "polymerization" factor (R20 Radii-Cal®/20 seconds; V20 Valo Cordless®/20 seconds; and V3 Valo Cordless®/3 seconds). All samples were stored for 6 months (water, 37ºC) and then subjected to a shear bond strength test (SBS). Bond failures were classified according to the Adhesive Remnant Index (ARI) and analyzed with the Kruskal-Wallis and Mann-Whitney tests (5%). Using the same factors, 120 resin discs were made to assess the degree of conversion (DC) of the monomer. Data from the SBS (MPa) and DC (%) were analyzed by analysis of variance (2 factors) and Tukey's test (5%). For the SBS, the factors "polymerization" (R20 = 8.1B; V20 = 13.2A; V3 = 5.2C, p = 0.0001) and "surface treatment" (A = 3.1C; ATxt = 13.6A; Tse = 12.3A; SBU = 6.3B, p = 0.0001) were statistically significant among groups. The highest adhesion value were found for the ATxt/V20 group (22.2A) and the lowest value for the A/R20 group (1.2E). Regarding ARI, score 2 was the most prevalent in groups A, ATxt, V20 and V3, while score 4 was the most prevalent in the Tse, SBU and R20 groups, with no significant difference between them (p = 1.0). Regarding DC, the factors "polymerization" (R20 = 66.6A; V20 = 58.4B; V3 = 45.1C, p = 0.0001) and "surface treatment" (A = 52B, ATxt = 59.7A, Tse = 51.4B, SBU = 63.8A, p = 0.0001) were statistically significant. Tse was more sensitive to the variations in polymerization protocols than the other surface treatments. Treatment A did not present suitable bond strength or degree of conversion.
Asunto(s)
Animales Bovinos Soportes Ortodóncicos Cementos de Resina/química Esmalte Dental/efectos de los fármacos Auto-Curación de Resinas Dentales/métodos Curación por Luz de Adhesivos Dentales/métodos Polimerizacion/efectos de los fármacos Ácidos Fosfóricos/química Valores de Referencia Factores de Tiempo Grabado Ácido Dental/métodos Ensayo de Materiales Distribución Aleatoria Adhesividad/efectos de los fármacos Reproducibilidad de los Resultados Análisis de Varianza Esmalte Dental/química Resistencia al Corte Transición de Fase Luces de Curación Dental
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