Lennartz A, Dohmen A, Bishti S, Fischer H, Wolfart S. Retrievability of implant-supported zirconia restorations cemented on zirconia abutments.
J Prosthet Dent 2018;
120:740-746. [PMID:
29807736 DOI:
10.1016/j.prosdent.2018.01.011]
[Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 01/18/2018] [Accepted: 01/18/2018] [Indexed: 11/17/2022]
Abstract
STATEMENT OF PROBLEM
Retrievability of implant-supported restorations is important. Data are lacking for cemented zirconia crowns on zirconia abutments.
PURPOSE
The purpose of this in vitro study was to investigate the influence of different cements and marginal discrepancy on the retrievability of implant-supported zirconia crowns. Furthermore, the influence of thermocycling on retrievability was evaluated.
MATERIAL AND METHODS
Thirty tapered Camlog zirconia abutments (6-degree taper, 6×4.3 mm) were used. Thirty zirconia crowns with 3 different marginal cementation discrepancies (70, 130, 190 μm) were fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) technology. Five cements for interim or semidefinitive cementation were used: eugenol-free zinc oxide (Freegenol) and acrylurethane (ImProv) and 3 different composite resin cements (X-Pand Implant, Dyna Implant, Telio CS Cem Implant). Specimens underwent either 3-day storage in sodium chloride or thermocycling (10 000 cycles). Crowns were removed by using a universal testing machine (UTM) and a clinical removal device. Data were analyzed using 1-way ANOVA and the Scheffé test (α=.05).
RESULTS
Thermocycling decreased the retention force significantly (P<.001). Marginal discrepancy (70 to 190 μm) was not significantly influential on retrievability (P>.05). Therefore, groups were pooled according to the factor of marginal discrepancy. The mean retention force using the UTM after 3-day storage and thermocycling was as follows: Freegenol, 235 ±42 N (thermocycling, 29 ±9 N); Improv, 110 ±50 N (thermocycling, 35 ±38 N); Telio CS, 104 ±17 N (thermocycling, 6 ±10 N); Dyna implant, 61 ±17 N (thermocycling, 1 ±1 N); and X-Pand, 50 ±16 N (thermocycling, 2 ±2 N).
CONCLUSIONS
Retention forces of the tested cements were significantly different and decreased considerably after thermocycling. Marginal cementation discrepancy between 70 and 190 μm did not influence retrievability.
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