Resumen de In vivo evaluation of two new moisture-resistant orthodontic adhesive systems: a comparative clinical trial
Antonios Mavropoulos, A. Karamouzos, G. Kolokithas
Objective: To evaluate and compare the clinical performance of two new moisture-resistant orthodontic adhesive systems: a chemically-cured composite resin (Unite, 3M Unitek, Monrovia, California, USA) in conjunction with a special moisture-resistant primer (Transbond MIP, 3M Unitek, Monrovia, California, USA); and a fluoride-releasing light-cured compomer (Assure, Reliance Orthodontic Products, Inc., Itasca, Illinois, USA).
Design: Randomized controlled clinical trial using the ‘split-mouth’ technique.
Setting: Department of Orthodontics, Aristotle University of Thessaloniki.
Subjects (Materials) and Methods: Twenty-five consecutively started patients (13 females and 12 males) requiring fixed appliance orthodontic treatment.
Interventions: Four-hundred-and-thirty-six stainless steel brackets bonded to all teeth except molars using two different moisture-resistant orthodontic adhesive systems.
Main outcome measures: Bond failure rates during a period of 9 months were estimated for each adhesive system and the corresponding bracket survival curves were plotted using the Kaplan– Meier product-limit estimate. Bracket survival distributions with respect to adhesive material, tooth location, patient’s gender and operator, were then compared by means of a log-rank test. Bond failure interface was determined using the Adhesive Remnant Index.
Results: Assure recorded a higher bond failure rate (13.8 per cent) than Unite & MIP (7.3 per cent). The corresponding bracket survival curves were found to be significantly different (P < 0.05). Premolars exhibited higher bond failures than incisors and canines (P < 0.001), while half (49.8 per cent) of the total bond failures occurred during the first 2 months of treatment. The predominant mode of failure was within the bonding material.
Conclusion: The new moisture-resistant adhesive systems under study were found to be clinically efficient, though Assure exhibited a significantly higher bond failure rate than Unite and Transbond MIP. The higher frequency of adhesive failures observed with Assure might indicate a possible weak point at the adhesive-bracket interface.
