Influence of curing modes on conversion and shrinkage of dual-cure resin-cements

Mohammed Aldhafyan; Nikolaos Silikas; David C Watts

doi:10.1016/j.dental.2021.12.004

Influence of curing modes on conversion and shrinkage of dual-cure resin-cements

Dent Mater. 2022 Jan;38(1):194-203. doi: 10.1016/j.dental.2021.12.004. Epub 2021 Dec 17.

Authors

Mohammed Aldhafyan¹, Nikolaos Silikas², David C Watts³

Affiliations

¹ Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Division of Dental Biomaterials Science, College of Dentistry, King Saud University, Saudi Arabia.
² Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK. Electronic address: Nick.Silikas@manchester.ac.uk.
³ Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, UK; Photon Science Institute, University of Manchester, UK. Electronic address: david.watts@manchester.ac.uk.

PMID: 34924201
DOI: 10.1016/j.dental.2021.12.004

Abstract

Objective: To explore the effect of curing modes of dual-cure resin cements on their degree of conversion (DC) and polymerization shrinkage (PS) over specific post-activation periods.

Methods: Five self-adhesive (PANAVIA SA, RelyX Universal Resin, RelyX Unicem 2, Bifix SE, and SpeedCEM Plus) and three conventional (PANAVIA V5, Nexus Third Generation, and RelyX Ultimate Universal) dual-cure resin cements were studied. Four specimens (n = 4) were made per curing mode (light/self-cure) to measure either DC or PS. FTIR was utilized to measure real-time DC (%) over 24 h. The Bonded Disk method was used to measure shrinkage at 23 °C over 1 h. The data were analyzed using one-way ANOVA, Tukey post-hoc tests and independent/ paired sample t-tests (a = 0.05).

Results: After 1 h post-activation, the DC of light-cured (LC) specimens ranged between 66.6% and 77.4%, whereas for self-cured (SC) specimens DC ranged between 44.4% and 73.2%. After 24 h, the DC of LC specimens ranged between 74.8% and 82.4% and between 62.7% and 81.7% for SC specimens. After 24 h, the DC of three cements (BSE, PV5, and RXU) were comparable between their curing modes (p > 0.05), whereas five cements (CEM, NX3, PSA, RXU2, RXL) had significantly lower DC for SC compared to LC specimens (p < 0.05). After 1 h post-activation, shrinkage ranged between 5.9% and 8.5% for LC and between 4.9% and 8.3% for SC specimens. Most cements were not significantly different between curing modes. However, light-cured PAS, RXL and RXU2 had significantly higher shrinkage (p < 0.05). After 1 h post-activation, a strong positive correlation existed between conversion and shrinkage (LC: r² = 0.95 and SC: r² = 0.93).

Significance: Whenever light access is possible, light-curing of resin-cements remains beneficial to the overall efficacy of their conversion and thus all factors that depend on that. Conversion and shrinkage behavior are intrinsically important factors in clinical selection of resin-cement products.

Keywords: Curing modes; Degree of conversion; Dual-cure resin-cements; FTIR; Shrinkage.

Publication types

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

MeSH terms

Dental Cements*
Light-Curing of Dental Adhesives
Materials Testing
Polymerization
Resin Cements*

Substances

Dental Cements
Resin Cements