Influence of Cement Film Thickness on the Retention of Implant-Retained Crowns

• Published in: Journal of prosthodontics 2013-12, Vol.22 (8), p.618-625
• Main Authors: Mehl, Christian, Harder, Sönke, Steiner, Martin, Vollrath, Oliver, Kern, Matthias
• Format: Article
• Language: English
• Subjects: CAD/CAM; Cement; Cementation - methods; Chromium Alloys - chemistry; Computer-Aided Design; crown; Crowns; Dental Abutments; Dental Cements - chemistry; Dental Implants; Dental Materials - chemistry; Dental Prosthesis Design; Dental Prosthesis Retention; Dental Prosthesis, Implant-Supported; Dental Stress Analysis - instrumentation; Dentistry; film thickness; Glass Ionomer Cements - chemistry; Humans; implant; Lasers; Materials Testing; Polycarboxylate Cement - chemistry; Rapid prototyping; Resin Cements - chemistry; Retention; retrievability; Stress, Mechanical; Surface Properties; Thin films; Time Factors; titanium; Titanium - chemistry; Water - chemistry
• ISSN: 1059-941X; 1532-849X
• DOI: 10.1111/jopr.12058

Purpose The main goal of this study was to establish a new, high precision procedure to evaluate the influence of cement film thickness on the retention of cemented implant‐retained crowns. Materials and Methods Ninety‐six tapered titanium abutments (6° taper, 4.3 mm diameter, Camlog) were shortened to 4 mm. Computer‐aided design was used to design the crowns, and selective laser sintering, using a cobalt‐chromium alloy, was used to produce the crowns. This method used a focused high‐energy laser beam to fuse a localized region of metal powder to build up the crowns gradually. Before cementing, preset cement film thicknesses of 15, 50, 80, or 110 μm were established. Glass ionomer, polycarboxylate, or resin cements were used for cementation. After 3 days storage in demineralized water, the retention of the crowns was measured in tension using a universal testing machine. Results The cement film thicknesses could be achieved with a high level of precision. Interactions between the factors cement and cement film thickness could be found (p ≤ 0.001). For all cements, crown retention decreased significantly between a cement film thickness of 15 and 50 μm (p ≤ 0.001). At 15 μm cement film thickness, the resin cement was the most retentive cement, followed by the polycarboxylate and then the glass ionomer cement (p ≤ 0.05). Conclusions The results suggest that cement film thickness has an influence on the retentive strength of cemented implant‐retained crowns.