Effects of the conventional, soft start, and pulse delay modes produced by light-emitting diode device on metal brackets bond strength and enamel damage: An in vitro comparative study.

Autor: Najjar YM; Department of Orthodontics, University of Damascus Dental School, Damascus, Syria., Burhan AS; Department of Pediatric Dentistry, Faculty of Dentistry, Syrian Private University, Damascus countryside, Syria., Hajeer MY; Department of Orthodontics, University of Damascus Dental School, Damascus, Syria. Electronic address: myhajeer@gmail.com., Nawaya FR; Department of Pediatric Dentistry, Faculty of Dentistry, Syrian Private University, Damascus countryside, Syria., Alam MK; Orthodontic Unit, Preventive Dentistry Department, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia.
Jazyk: angličtina
Zdroj: International orthodontics [Int Orthod] 2023 Sep; Vol. 21 (3), pp. 100787. Date of Electronic Publication: 2023 Jun 30.
DOI: 10.1016/j.ortho.2023.100787
Abstrakt: Objectives: This study aimed to compare the bond strength and enamel damage following debonding of metal brackets cured by different light-curing modes: conventional, soft start, and pulse delay modes.
Material and Methods: Sixty extracted upper premolars were randomly divided into three groups according to the used light-curing mode. Metal brackets were bonded with a light-emitting diode device employing different modes. Group 1: conventional mode (10s mesial+10 s distal); group 2: soft start mode (15s mesial+15s distal); group 3: pulse delay mode (3s mesial+3s distal, followed by 3min of no photoactivation, then 9s mesial+9s distal). Radiant exposure was the same in all study groups. Shear bond strengths of the brackets were tested with a universal testing machine. A stereomicroscope was used to determine the number and length of enamel microcracks. One-Way ANOVA and Kruskal-Wallis tests were used to detect significant differences in shear bond strength and microcracks number and length among groups.
Results: The soft start and pulse delay modes produced significantly greater shear bond strength than the conventional mode (19.46±4.90MPa; 20.47±4.97MPa; 12.14±3.79MPa, respectively, P<0.001). However, there was no significant difference between the soft start and pulse delay groups (P=0.768). The number and length of microcracks increased significantly after debonding in all study groups. The change in microcracks length was not different among study groups.
Conclusion: The soft start and pulse delay modes produced greater bond strength than the conventional mode without predisposing enamel to higher risk of damage. Conservative methods for debonding are still required.
(Copyright © 2023 CEO. Published by Elsevier Masson SAS. All rights reserved.)
Databáze: MEDLINE
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