The impact of surface preparation on shear bond strength of metallic orthodontic brackets bonded with a resin-modified glass ionomer cement

• Autores: Ayman A S Elnafar, Mohammed Alam, Hasan Rozita
• Localización: Journal of orthodontics, ISSN-e 0301-228X, ISSN 1465-3125, Nº. 3, 2014, págs. 201-207
• Idioma: inglés
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• Resumen

  • The aim of this study was to assess the effects of four enamel preparation techniques on shear bond strength (SBS) of brackets bonded with a resin-modified glass ionomer cement (RMGIC). Adhesive Remnant Index (ARI) and enamel surface roughness (Ra) were also investigated after cement removal. Materials and methods: One hundred and forty-four human premolars were divided into four groups (n = 36 in each group) as follows: Group 1, 37% phosphoric acid (i.e. conventional); Group 2, sandblasting; Group 3, sodium hypochlorite and 37% phosphoric acid; and Group 4, sodium hypochlorite and sandblasting. Twenty-four hours after bonding, the brackets were debonded with an Instron machine using a crosshead speed of 1·0 mm/min; the ARI was evaluated by an image analyser system; the Ra was measured by profilometry; and the morphology of the tooth enamel surface was observed by scanning electron microscope evaluation. Data were submitted to ANOVA and the Kruskal�Wallis test (? = 0·05). Results: Mean SBS values for Groups 1�4 were 13·86, 9·08, 17 and 9·63 MPa, respectively. Mean ARI for Groups 1�4 were 11·16, 2·06, 20·66 and 3·73%. The SBS and ARI showed statistically significant differences between the four groups (P<0·001). The Ra (?m) showed no significant differences between groups.