6 Study on adhesion of orthodontic brackets on enamel with resin cements

Abstract

We evaluated the mechanical properties and bond strength of commercially available adhesives used with ortho-dontic brackets on enamel. Debonding of brackets must be done gently so as not to create pain or injury to the enamel. Three commercially available adhesive resin cements, Super-Bond (SB), Beauty Ortho Bond (BO) and Rely X^<TM> Unicem 2 Automix (UN) were used. Two self-etching primer adhesive systems, Beauty Ortho Bond (BO) and Rely X^<TM> Unicem 2 Automix (UN) were used. The bond strength to enamel of SB placed in 37℃ water was 18.8 Mpa after one day, 16.6 Mpa after 6 months, and 19.2 Mpa after one year. The bond strength to enamel of BO in 37℃ water was 11.6 Mpa after one day, 8.9 Mpa after six months, and 13.6 Mpa after one year. The bond strength to enamel of UN in 37℃ water was 5.8 Mpa after one day, 4.0 Mpa after six months, and 13.6 Mpa after one year. The adhesives showed excellent bond strength of approximately 6〜15 Mpa with both precious alloy brackets after 10,000 thermocycles consisting of alternately immersing the specimens in 5℃ and 55℃ water for one minute each. We concluded that the application of adhesives greatly improvied the bond strength of the resin cements.