Evaluation of shear bond strength and adhesive remnant index of metal APC™ Flash-Free adhesive system: A comparative in vitro study with APC™ II and uncoated metal brackets

Roula Akl; Joseph Ghoubril; Michel Le Gall; Rania Shatila; Camille Philip-Alliez

doi:10.1016/j.ortho.2022.100705

Evaluation of shear bond strength and adhesive remnant index of metal APC™ Flash-Free adhesive system: A comparative in vitro study with APC™ II and uncoated metal brackets

Int Orthod. 2022 Dec;20(4):100705. doi: 10.1016/j.ortho.2022.100705. Epub 2022 Oct 22.

Authors

Roula Akl¹, Joseph Ghoubril², Michel Le Gall³, Rania Shatila⁴, Camille Philip-Alliez³

Affiliations

¹ Department of Orthodontics, School of Dental Medicine, Saint Joseph University, Beirut, Lebanon.
² Department of Orthodontics, School of Dental Medicine, Saint Joseph University, Beirut, Lebanon. Electronic address: joseph.ghoubril@usj.edu.lb.
³ Service d'Orthopédie Dento-Faciale, Hôpital de la Timone, 264, rue Saint-Pierre, 13005 Marseille, France.
⁴ Kamal A. Shair Central Research Science Laboratory, Faculty of Arts and Sciences, American University of Beirut, Riad El-Solh, P.O. Box: 11-0236, 1107 2020 Beirut, Lebanon.

PMID: 36280583
DOI: 10.1016/j.ortho.2022.100705

Abstract

Objective: The aim of this in vitro study was to compare the shear bond strength (SBS) and the adhesive remnant index (ARI) of the metal APC™ Flash-Free adhesive system, the APC™ pre-coated adhesive system and a conventional uncoated system.

Materials and methods: One hundred eighty-six freshly extracted human premolars were randomly divided into 3 groups and bonded by a single operator. Group A/Control Group (60 teeth): the manual bonding group treated with Transbond™ XT Light Cure Adhesive Paste (3M™ Unitek). Group B (60 teeth): treated with APC™II metal maxillary premolar precoated brackets. Group C (66 teeth): treated with metal maxillary premolar APC Flash-Free brackets. The teeth were then stored in distilled water at 37̊C for 24hours, and five hundred cycles of thermocycling were performed. The Shear Bond Strength (SBS) test was performed using an Instron Universal Testing Machine, and the adhesive remnant index (ARI) was determined using a dental optical microscope at ×25 magnification.

Results: The mean shear bond strength values showed differences between the three types of brackets (P=0.016; Anova). It was significantly higher with APC™II and lower with APC Flash-Free brackets; however, no significant differences were found between conventional and APC Flash-Free brackets (P-value=0.574). The distribution of the dichotomized ARI score was significantly different between the three brackets (P-value=0.049). The ARI score for APC Flash-Free brackets was higher with no significant difference between the conventional system and APC brackets (P-value=0.361).

Conclusions: The mean SBS values were not significantly different between APC Flash-Free metal brackets and uncoated metal brackets. The APC Flash-Free metal system's bond failure occurred at the bracket-adhesive interface, with the highest percentage of teeth having more than 50% of the residual composite on the enamel after debonding.

Keywords: Adhesive remnant index; Flash-Free; Precoated brackets; Shear bond strength.

MeSH terms

Dental Bonding*
Dental Cements
Dental Stress Analysis
Humans
Materials Testing
Orthodontic Brackets*
Shear Strength
Surface Properties

Substances

Dental Cements