Pairing orthodontic adhesive resins and light-curing units for optimal degree of conversion

Rachel Soyland; G Frans Currier; Onur Kadioglu; Ji Li; Fernando L Esteban Florez; Frederick A Rueggeberg; Sharukh S Khajotia

doi:10.1016/j.ejwf.2020.02.002

Pairing orthodontic adhesive resins and light-curing units for optimal degree of conversion

J World Fed Orthod. 2020 Jun;9(2):68-74. doi: 10.1016/j.ejwf.2020.02.002. Epub 2020 Apr 13.

Authors

Rachel Soyland¹, G Frans Currier², Onur Kadioglu³, Ji Li⁴, Fernando L Esteban Florez⁵, Frederick A Rueggeberg⁶, Sharukh S Khajotia⁷

Affiliations

¹ Graduate Orthodontics Program, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
² Program Chair, Division of Orthodontics, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
³ Graduate Program Director, Division of Orthodontics, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
⁴ Research Biostatistician, Hudson College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
⁵ Assistant Professor, Division of Dental Biomaterials, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
⁶ Professor and Director, Section of Dental Materials, Department of Restorative Sciences, The Dental College of Georgia at Augusta University, Augusta, Georgia.
⁷ Professor and Head, Division of Dental Biomaterials, College of Dentistry, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma. Electronic address: sharukh-khajotia@ouhsc.edu.

PMID: 32672657
DOI: 10.1016/j.ejwf.2020.02.002

Abstract

Objectives: The purpose of this study was to identify the combination of orthodontic adhesive resins and light-emitting diode (LED) light-curing units (LCUs) that result in the highest degree of resin conversion (DC). The hypothesis tested was that pairing orthodontic resins with LCUs from the same manufacturer produces higher DC versus unpaired resins and LCUs.

Methods: Pre-polymerization spectra of adhesive resins (Transbond XT [3M Unitek], BracePaste [American Orthodontics] or Opal Bond MV [Opal by Ultradent]) were obtained at oral temperature (37°C) using an attenuated total reflectance (ATR) diamond crystal (Golden Gate, Specac) in a Fourier-transform infrared (FTIR) spectrometer (Nicolet IS50). Resin specimens were polymerized using various LCUs (Ortholux Luminous [3M Unitek], Blue Ray 3 [American Orthodontics], or VALO Ortho Cordless [Ultradent Products, Inc.]) before obtaining post-polymerization infrared (IR); spectra. Twelve LCU-resin combinations were tested (n = 20/combination), half with a bracket present (Mini Diamond Twin, Ormco) and half without. DC values (%) were calculated using the two-frequency method and tangent-baseline technique. Data for each resin were statistically analyzed using General Linear Models and Student-Newman-Keuls post hoc tests (α = 0.05).

Results: Statistically significant differences were found within each resin for the groups without brackets present (P < 0.0001), the groups with brackets present (P < 0.0001), and the groups with brackets when compared with the manufacturer-paired group without a bracket (P < 0.0001).

Conclusions: Adhesive resins and LCUs from the same manufacturer did not consistently result in statistically higher mean DC values than unpaired combinations. Metal brackets do not uniformly reduce the degree of conversion of adhesive resins when assessed using IR spectrometry.

Keywords: Adhesives; Degree of conversion; Fourier-transform infrared spectroscopy; Orthodontic resins; Polymerization.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Composite Resins* / chemistry
Curing Lights, Dental*
Humans
Light-Curing of Dental Adhesives*
Materials Testing*
Orthodontic Brackets
Orthodontics / instrumentation*
Polymerization
Spectroscopy, Fourier Transform Infrared

Substances

Composite Resins