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J. Stomat. Occ. Med. (2010) 3: 106110 DOI 10.1007/s12548-010-0052-6 Printed in Austria Springer-Verlag 2010
Comparison of the marginal t of different all-ceramic and metal-ceramic crown systems: an in vitro study
R. Polansky, A. Heschl, G. Arnetzl, M. Haas, W. Wegscheider
Division of Prosthodontics, Restorative Dentistry, Periodontology and Implantology, Department of Dentistry
and Maxillofacial Surgery, School of Dentistry, Medical University of Graz, Graz, Austria Received February 10, 2010; Accepted April 10, 2010
Statement of problem: High levels of fracture resistance offered by todays ceramic crown systems might eliminate the need for adhesive cementation. However, high accuracy of t involving gap widths <75 mm is also required for conventional cementation.
Purpose: This in vitro study was performed to evaluate six ceramic crown systems for their accuracy of t.
Material and methods: A total of 60 experimental crowns were fabricated from four all-ceramic systems (Vita Mark II/ Cerec 2, IPS Empress/staining, Vita In-Ceram Alumina/Cerec 2, and Procera All-Ceram) and two metal-ceramic systems (electroformed or conventional copings). All restorations were delivered to prefabricated stone dies with conventional zinc-phosphate cement. Gap widths were measured by light microscopy (magnication 200). Intergroup differences were
analyzed by one-way ANOVA. KolmogorovSmirnov test was used to evaluate normal distribution plots and box plots of different measurements within each group.
Results: Marginal gaps averaged 142.3 mm for Vita Mark II, 109.3 mm for IPS Empress, 98.1 mm for Vita In-Ceram Alumina, and 47.3 mm for Procera All-Ceram. Galvano-ceramic and metal-ceramic restorations yielded 68.5 and 77.5 mm. Differences reached statistical signicance for Vita Mark II versus all other systems except IPS Empress; for galvanic restorations versus Vita Mark II and IPS Empress; and for Procera All-Ceram versus all other all-ceramic systems.
Conclusions: The incorporation of all ceramic crowns requires different ways of cementation, depending on the marginal gap. This in vitro study showed that Procera All-Ceram crowns can be conventionally cemented with zinc-phosphate cement.
Clinical implications: Procera All-Ceram crowns offer marginal gap widths well below 75 mm. Therefore they can be cemented with conventional zinc-phosphate cement. Different cementation techniques are strongly recommended for all other all-ceramic systems tested.
Keywords: ceramic crown systems, marginal gap, cementation techniques
IntroductionEssential requirements for the clinical success of all-ceramic crown restorations include good esthetics, high fracture resistance, and perfect...