مقايسه استحكام برشي باند يك نوع سيانو آكريلات جديد با يك نوع كامپوزيت رايج براي باندينگ براكت هاي ارتودنسي

A comparative study on shear bond strength of a new cyanoacrylate and a conventional composite resin for orthodontic bondings

Background and Aim: Debonding of bracket is one of the common problem in orthodontics. The goal of this study was to evaluate and compare shear bond strength of a new cyanoacrylate, a kind of moisture polymerized adhesive, with a conventional composite resin for orthodontic bondings. Materials and Methods: In this experimental study, based on observational technique, a total number of 74 caries free extracted premolar teeth of (12-16) - year - old patients, were collected, water - rinsed and polished with pumice. Samples were randomly assigned in two groups. In group I, the teeth were etched with 37% phosphoric acid, the primer was applied and the brackets were bonded with Unite No - mix composite. In group II, the teeth were etched with 35% phosphoric acid and the brackets were bonded with Smart bond. The specimens were mounted and subjected to a crosshead speed of 0.5 mm/min of Instron machine. Shear bond strength (SBS) differences between two groups were evaluated statistically using Kolmogrov - Smirnov test and t - test. Results: The results of this study indicated that no significant difference, in shear bond strength, existed between cyanoacrylate and No - mix composite groups (P=0.468). Moreover, there was no statistically significant difference, in debonding area, between two groups (P<0.001) so as debonding occurred mostly inside adhesive among cyanoacrylate group indicating a kind of cohesive failure. Conclusion: Cyanoacrylate has the potentiality to be used as a bonding agent for orthodontic brackets.