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