Jiajing Yao1, Jing Li2, Yuhua Wang2, Hui Huang3. 1. Resident, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China. 2. Attending Doctor, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China. 3. Associate Clinical Professor, Department of Prosthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai, China. Electronic address: huanghui_68@126.com.
Abstract
STATEMENT OF PROBLEM: Limited information is available concerning the properties of computer-aided designed/computer-aided manufactured (CAD/CAM) interim materials. PURPOSE: The purpose of this study was to investigate the flexural strength and marginal accuracy of 2 traditional bis-acryl composite resin interim materials (Protemp 4 and Structur 2 SC/QM) and 2 CAD/CAM interim materials (Teilo CAD and VITA CAD-Temp). MATERIAL AND METHODS: Standard specimens (25 × 2 × 2 mm) of the 4 materials were made (n=20). Each group contained 10 specimens fractured under 3-point loading in a universal testing machine with a cross-head speed of 1 mm/min. The other 10 specimens were subjected to 5000 thermal cycles (5°C and 55°C) before testing. Four groups of interim crowns were fabricated from the 4 materials on models of a prepared left maxillary first molar (n=10). Twenty-four hours after cementing the crowns, margin discrepancies were measured under a stereomicroscope. The crowns then were subjected to 5000 thermal cycles (5°C and 55°C), and the margin discrepancies were measured again. RESULTS: Teilo CAD showed the highest mean flexural strength of the 4 interim materials before and after thermal cycling, and VITA CAD-Temp showed the lowest (P<.05). After thermal cycling, the flexural strength decreased significantly (P<.05). The margin discrepancies were larger for the bis-acryl interim crowns than for the CAD/CAM crowns before and after thermal cycling (P<.05). After thermal cycling, the margin discrepancies in the bis-acryl interim crowns were larger (P<.05); however, no significant differences were found for the margin discrepancies in the CAD/CAM interim crowns (P>.05). CONCLUSIONS: CAD/CAM interim materials were stronger and had better marginal accuracy properties than bis-acryl materials, especially after thermal cycling.
STATEMENT OF PROBLEM: Limited information is available concerning the properties of computer-aided designed/computer-aided manufactured (CAD/CAM) interim materials. PURPOSE: The purpose of this study was to investigate the flexural strength and marginal accuracy of 2 traditional bis-acryl composite resin interim materials (Protemp 4 and Structur 2 SC/QM) and 2 CAD/CAM interim materials (Teilo CAD and VITA CAD-Temp). MATERIAL AND METHODS: Standard specimens (25 × 2 × 2 mm) of the 4 materials were made (n=20). Each group contained 10 specimens fractured under 3-point loading in a universal testing machine with a cross-head speed of 1 mm/min. The other 10 specimens were subjected to 5000 thermal cycles (5°C and 55°C) before testing. Four groups of interim crowns were fabricated from the 4 materials on models of a prepared left maxillary first molar (n=10). Twenty-four hours after cementing the crowns, margin discrepancies were measured under a stereomicroscope. The crowns then were subjected to 5000 thermal cycles (5°C and 55°C), and the margin discrepancies were measured again. RESULTS: Teilo CAD showed the highest mean flexural strength of the 4 interim materials before and after thermal cycling, and VITA CAD-Temp showed the lowest (P<.05). After thermal cycling, the flexural strength decreased significantly (P<.05). The margin discrepancies were larger for the bis-acryl interim crowns than for the CAD/CAM crowns before and after thermal cycling (P<.05). After thermal cycling, the margin discrepancies in the bis-acryl interim crowns were larger (P<.05); however, no significant differences were found for the margin discrepancies in the CAD/CAM interim crowns (P>.05). CONCLUSIONS: CAD/CAM interim materials were stronger and had better marginal accuracy properties than bis-acryl materials, especially after thermal cycling.
Authors: Sinan Şen; Ralf Erber; Kevin Kunzmann; Stefanie Kirschner; Vanessa Weyer; Lothar Schilling; Marc A Brockmann; Stefan Rues; Gül Orhan; Christopher J Lux; Sebastian Zingler Journal: Clin Oral Investig Date: 2018-03-09 Impact factor: 3.573