Shan Song1, Zheng Zheng1, Li-Yuan Yang1, Xu Gao1. 1. Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Dept. of Prosthodontics, School of Stomatology, Shandong University, Jinan 250012, China.
Abstract
OBJECTIVE: This study aimed to compare the passive fits of implant-supported cement-retained computer aided design/computer aided manufacturing (CAD/CAM) bridges fabricated with different implant superstructure designs from zirconia and titanium. METHODS: A total of 32 cubic clods with the same dimensions and with elastic modulus similar to that of mandibles were used. Each clod received two one-stage implants to simulate a partially edentulous jaw that was missing teeth between the lower left second premolar and second molar. Four linear strain gauges were bonded on the region surrounding each implant on the mesial, buccal, distal, and lingual aspects. A total of 32 identical frameworks were fabricated through CAD/CAM after scanning. The frameworks were allocated into four different groups (n=8) in accordance with material types and superstructure designs. Group A included zirconia ceramic implant-supported fixed prostheses with regular marginal designs. Group B comprised zirconia ceramic implant-supported fixed prostheses with full circumferential zirconia-collar marginal designs. Group C consisted of titanium ceramic implant-supported fixed prostheses with regular marginal designs. Group D included titanium ceramic implant-supported fixed prostheses with full circumferential titanium-collar marginal designs. Strain development before and after ceramic veneering was recorded during cement setting. Data were statistically analyzed by using SPSS software. RESULTS: Before ceramic veneering, material types affected the strains of prostheses, and zirconia frameworks showed lower strain than other frameworks (P<0.01). Designs affected the strains of prostheses, and frameworks with full collar marginal design showed lower strain than other frameworks (P<0.01). These two factors showed interactions (P<0.01). The strain of decorative porcelain increased after sintering. The two groups of different materials did not significantly differ (P>0.05). Nevertheless, the full circumferential collar marginal design reduced discrepancies among groups (P<0.01). CONCLUSIONS: The passive fits of zirconia prostheses were better than those of titanium-based porcelain-fused-to-metal restorations. The full circumferential collar marginal design can help reduce fit inaccuracy, as well as the adverse effects of ceramic veneering.
OBJECTIVE: This study aimed to compare the passive fits of implant-supported cement-retained computer aided design/computer aided manufacturing (CAD/CAM) bridges fabricated with different implant superstructure designs from zirconia and titanium. METHODS: A total of 32 cubic clods with the same dimensions and with elastic modulus similar to that of mandibles were used. Each clod received two one-stage implants to simulate a partially edentulous jaw that was missing teeth between the lower left second premolar and second molar. Four linear strain gauges were bonded on the region surrounding each implant on the mesial, buccal, distal, and lingual aspects. A total of 32 identical frameworks were fabricated through CAD/CAM after scanning. The frameworks were allocated into four different groups (n=8) in accordance with material types and superstructure designs. Group A included zirconia ceramic implant-supported fixed prostheses with regular marginal designs. Group B comprised zirconia ceramic implant-supported fixed prostheses with full circumferential zirconia-collar marginal designs. Group C consisted of titanium ceramic implant-supported fixed prostheses with regular marginal designs. Group D included titanium ceramic implant-supported fixed prostheses with full circumferential titanium-collar marginal designs. Strain development before and after ceramic veneering was recorded during cement setting. Data were statistically analyzed by using SPSS software. RESULTS: Before ceramic veneering, material types affected the strains of prostheses, and zirconia frameworks showed lower strain than other frameworks (P<0.01). Designs affected the strains of prostheses, and frameworks with full collar marginal design showed lower strain than other frameworks (P<0.01). These two factors showed interactions (P<0.01). The strain of decorative porcelain increased after sintering. The two groups of different materials did not significantly differ (P>0.05). Nevertheless, the full circumferential collar marginal design reduced discrepancies among groups (P<0.01). CONCLUSIONS: The passive fits of zirconia prostheses were better than those of titanium-based porcelain-fused-to-metal restorations. The full circumferential collar marginal design can help reduce fit inaccuracy, as well as the adverse effects of ceramic veneering.
Entities:
Keywords:
implant-supported prostheses; passive fit; strain; superstructure of implant
Authors: Jaafar Abduo; Vincent Bennani; Neil Waddell; Karl Lyons; Michael Swain Journal: Int J Oral Maxillofac Implants Date: 2010 May-Jun Impact factor: 2.804
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