SHEAR BOND STRENGTH OF ORTHODONTIC BRACKETS BOND WITH TWO TYPES OF BONDING AGENTS AND EXPOSED TO ACIDIC BEVERAGES

Abstract

Objective: To evaluate the influence of acidic beverageson the bond strength of orthodontic brackets bonded with the resinous agents Transbond ™ PLUS Color Change (TPCC) and Ortholink ™.The Adhesive Remnant Index (ARI) after bracket removal was further quantified, in order to determine which composite has a higher resistance to shear stress and where there was adhesive failure. Material and Methods: Ninety-six bovine incisors had brackets bonded on their vestibular surfaces and were divided into two groups (n = 48), according to the bonding agent used: I) TPCC and II) Ortholink. Then, each group was divided into four subgroups (n = 12) in accordance with the substance inwhich the samples would be immersed: S1) Coca-Cola®, S2) Orange juice Del Valle®, S3) Gatorade® and S4) artificial saliva (control). Samples of subgroups S1, S2 and S3 were subjected to three corrosive cycles daily for 5 minutes with 2 hours intervals for 30 days, each being replaced in artificial saliva until a new cycle was started. At the end of this period, sampleswere subjected to mechanical shear test and the ARI assessment. Results: No statistically significant differences were found betweenthe compositesand between the subgroups for the two parameters tested (P>0.05). Conclusion: There was no influence of acidic beverageson the bond strength of the composites, asboth showedsimilar resistance, and the resin/bracket interfaces as well asthe bracket/tooth interfaces showed adhesive failures. DESCRIPTORS Orthodontic Brackets. Shear Strength. Orthodontics.