Evaluation of composite resin surface treatment in the union resistance of metallic brackets

Vol. 15 – Number 58 – 2022 Original article Page 100-106 Evaluation of composite resin surface treatment in the union resistance of metallic brackets Nelson Faé Júnior¹ Diego Patrik Alves Carneiro¹ Américo Bortolazzo Correr² William Custódio¹ Mário Vedovello Filho¹ Heloísa Cristina Valdrighi¹ Abstract The aim of this in vitro experimental study was to evaluate the shear bond strength of bracket bonding in different composite resin surface treatments associated with two bonding agents. Ninety specimens were made with Filtek Z350 composite resin (3M/ESPE). The specimens were randomly divided into nine groups (n=10): (1) control group; (2) silane and primer; (3) universal adhesive (5) phosphoric acid, silane and primer (4) phosphoric acid, universal adhesive; (6) hydrofluoric acid, silane and primer; (7) hydrofluoric acid and universal adhesive; (8) drill, silane and primer and (9) universal drill and adhesive. Transbond XT/3M orthodontic resin was then applied to the bonding surface of the metal bracket (Standart Edgewise for upper central incisor – Morelli, Sorocaba/SP). The bracket was bonded to the Filtek Z350 composite resin (3M/ ESPE). After 24 hours they were submitted to the shear bond test on the Instron machine at a speed of 0.5mm/min. Data were submitted to ANOVA and Tukey test. Then the Adhesive Remnant Index (ARI) was evaluated. There was no significant difference between bonding agents regarding bond strength (p> 0.05). The eight groups that received bonding agents showed significantly higher resistance than the control group (p <0.05). The group prepared with hydrofluoric acid presented lower resistance than those prepared with phosphoric acid (with silane + transbond primer) and diamond drill (with silane + transbond primer and universal adhesive), p <0.05. It was concluded that the surface treatment influences the bond strength. Descriptors: Shear bond strength, orthodontic brackets, composite resins. ¹ Department of Orthodontics – School of Dentistry of Araras. ² Department of Dental Materials – Faculty of Dentistry of Piracicaba. DOI: 10.24077/2022;1558-0185214