Effect of thermocycling on the surface properties of CAD-CAM denture base materials after different surface treatments

Sevda Atalay; Gülce Çakmak; Manrique Fonseca; Martin Schimmel; Burak Yilmaz

doi:10.1016/j.jmbbm.2021.104646

Effect of thermocycling on the surface properties of CAD-CAM denture base materials after different surface treatments

J Mech Behav Biomed Mater. 2021 Sep:121:104646. doi: 10.1016/j.jmbbm.2021.104646. Epub 2021 Jun 16.

Authors

Sevda Atalay¹, Gülce Çakmak², Manrique Fonseca³, Martin Schimmel⁴, Burak Yilmaz⁵

Affiliations

¹ Department of Prosthodontics, Faculty of Dentistry, Istanbul Okan University, Istanbul, Turkey.
² Buser Foundation Scholar, Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
³ Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland. Electronic address: manrique.fonseca@zmk.unibe.ch.
⁴ Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; Division of Gerodontology and Removable Prosthodontics, University Clinics of Dental Medicine, University of Geneva, Geneva, Switzerland.
⁵ Department of Reconstructive Dentistry and Gerodontology, School of Dental Medicine, University of Bern, Bern, Switzerland; Department of Restorative, Preventive and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland; Division of Restorative and Prosthetic Dentistry, The Ohio State University, Ohio, USA.

PMID: 34166873
DOI: 10.1016/j.jmbbm.2021.104646

Abstract

Purpose: To evaluate the effect of thermocycling on the water contact angle (WCA), surface roughness (SR), and microhardness (MH) of different CAD-CAM PMMA denture base materials after different surface treatments (conventional laboratory polishing, polishing kit, or surface sealant).

Materials and methods: Disk-shaped specimens (10 × 2 mm) of 3 different CAD-CAM PMMAs, AvaDent (AV); Merz M-PM (M-PM); Polident (Poli), and a conventional heat-polymerized PMMA (Vynacron) (CV) (n=21) were divided into 3 different surface treatment groups (n=7): conventional laboratory polishing (CLP), polishing with acrylic resin polisher kit (PK), and a surface sealant (Palaseal) (SSC). Stereomicroscopic images were taken both before and after thermocycling. WCA, SR, and MH of all specimens were measured before and after thermocycling and compared by using a 2-way ANOVA (α=0.05).

Results: After thermocycling, WCA significantly increased for CLP- or PK -applied (P<.001) specimens of all materials and SSC-applied M-PM (P=.002), SR significantly increased for CLP-applied M-PM (P=.027) and PK-applied Poli (P=.041), and MH significantly decreased for CLP- or PK-applied AV (P = .001, P < .001, respectively), CV (P=.033, P=.023, respectively), and M-PM (P=.003, P=.001, respectively), SSC-applied M-PM (P<.001), and CLP-applied Poli (P<.001). Stereomicroscopic images revealed rougher surfaces for PK-applied specimens.

Conclusions: After thermocycling, surface treatment had a significant effect on water contact angle and surface roughness. CLP or PK application resulted in hydrophobic surfaces compared with before thermocycling. CLP or SSC application on CAD-CAM PMMAs resulted in smoother surfaces. Thermocycling lowered the microhardness of all PMMAs, and the decrease was significant in CLP- or PK-applied PMMAs, except for PK-applied Poli.

Keywords: CAD-CAM materials; Microhardness; PMMA dentures; Surface roughness; Thermocycling; Water contact angle.

MeSH terms

Computer-Aided Design
Dental Materials
Denture Bases*
Materials Testing
Polymethyl Methacrylate*
Surface Properties

Substances

Dental Materials
Polymethyl Methacrylate