COMPARATIVE in vitro STUDY ON THE BOND STRENGTH OF TWO ORTHODONTIC ADHESIVES AFTER DENTAL BLEACHING

The aim of the paper is identifying differences in bracket bond strength between bleached and non-bleached teeth when using two different adhesives. Forty human premolars have been divided in four groups: two control groups were bonded using 2 different adhesives Transbond XT (3M) and Light Bond (Reliance Ortho) and two test groups that have been bleached with 35% hydrogen peroxide and preserved for one week prior to bonding with the two adhesives. After debonding, Shear bond strength (SBS) was calculated, Adhesive remnant index (ART) scores were evaluated and certain surfaces were examined under Scanning electronic microscopy (SEM). SBS values obtained for the two adhesives are similar. There is no difference between SBS of unbleached and bleached teeth seven days after the procedure using 35% hydrogen peroxide. ARI scores are significantly different for bleached teeth showing lower values, meaning higher prevalence of adhesive fracture at the enamel-adhesive interface.