Shear bond strength of orthodontic brackets to specimens fabricated from temporary restorative materials by 3D-printing, CAD/CAM technology, and the conventional technique after surface treatment by sandblasting and laser

Sara Alijani; Farnoush Fotovat; Loghman Rezaei Soufi; Behnaz Alafchi; Mohammad Hossein Mohammadkhani

doi:10.1016/j.ortho.2023.100790

Shear bond strength of orthodontic brackets to specimens fabricated from temporary restorative materials by 3D-printing, CAD/CAM technology, and the conventional technique after surface treatment by sandblasting and laser

Int Orthod. 2023 Dec;21(4):100790. doi: 10.1016/j.ortho.2023.100790. Epub 2023 Jul 6.

Authors

Sara Alijani¹, Farnoush Fotovat², Loghman Rezaei Soufi³, Behnaz Alafchi⁴, Mohammad Hossein Mohammadkhani⁵

Affiliations

¹ Department of Orthodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
² Department of Prosthodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran. Electronic address: ffotovat67@yahoo.com.
³ Department of Restorative Dentistry, Dental Research Center, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.
⁴ Modeling of Noncommunicable Diseases Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
⁵ School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran.

PMID: 37421919
DOI: 10.1016/j.ortho.2023.100790

Abstract

Objectives: This study assessed the shear bond strength (SBS) of stainless steel (SS) orthodontic brackets to specimens fabricated from polymethyl methacrylate (PMMA) temporary restorative material by 3D-printing, computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and the conventional technique, after surface treatment by sandblasting and laser.

Material and methods: In this in vitro study, 60 disc-shaped specimens with 8mm diameter and 1mm height were fabricated from PMMA temporary restorative material by 3D-printing, CAD/CAM, and the conventional technique. In each group (n=20), half of the specimens were sandblasted while the other half underwent Er,Cr:YSGG laser irradiation. Brackets were bonded to the specimens and underwent thermocycling followed by SBS testing. Data were analysed by one-way ANOVA, independent t-test, and LSD test (alpha=0.05).

Results: A significant difference existed among the three fabrication methods in SBS in both laser (P<0.001) and sandblasting (P<0.001) surface treatment groups. In laser group, the mean SBS of CAD/CAM (P=0.000) and conventional (P=0.000) groups was significantly lower than that of 3D-printing group. In sandblasting group, the SBS of CAD/CAM group was significantly lower than 3D-printing (P=0.000) and conventional (P=0.000) groups. The mean SBS of laser-treated specimens was significantly higher than sandblasted specimens in 3D-printing group (P=0.000), and significantly lower than sandblasted specimens in the conventional group (P=0.000). A significantly higher SBS was obtained by laser treatment compared with sandblasting irrespective of the fabrication method (P=0.000).

Conclusion: The highest SBS of SS orthodontic brackets to temporary restorative material was recorded for 3D-printed specimens treated by Er,Cr:YSGG laser irradiation.

Keywords: Dental restoration; Orthodontic brackets; Shear strength; Temporary.

MeSH terms

Computer-Aided Design
Dental Bonding* / methods
Dental Materials / chemistry
Humans
Lasers, Solid-State*
Materials Testing
Orthodontic Brackets*
Polymethyl Methacrylate
Printing, Three-Dimensional
Shear Strength
Surface Properties
Technology

Substances

Polymethyl Methacrylate
Dental Materials