Marginal and internal fit of posterior three-unit fixed zirconia dental prostheses fabricated with two different CAD/CAM systems and materials.
OBJECTIVE
The purpose of this in vitro study was to compare the precision of fit of frameworks milled from semi-sintered regular zirconia and high-translucent (HT) zirconia blanks, fabricated with two different CAD/CAM systems.


METHODS
Three-unit, posterior fixed dental prostheses (FDP) frameworks were fabricated for standardized dies (n = 11) with two different laboratory computer-aided design (CAD)/computer-aided manufacturing (CAM) systems (Cercon/Ceramill). The replica technique was used to evaluate the marginal and internal fit under an optical microscope. Evaluation of the data was performed according to prior studies at a level of significance of 5%.


RESULTS
The systems showed a statistically significant influence on the internal fit of the frameworks (p ≤ 0.001) and on the marginal fit (p < 0.001). The type of material showed no influence on the marginal fit for the Cercon system (p = 0.636) and on the marginal fit (p = 0.064) and the internal fit (p = 0.316) for the Ceramill system, while regular zirconia from Cercon showed higher internal values than HT zirconia (p = 0.016).


CONCLUSIONS
Both investigated systems showed clinically acceptable values within the limitations of this in vitro study. However, one showed less internal accuracy when regular zirconia was used.
Department of Prosthodontics, Munich Dental School, Goethestr. 70, 80336, Munich, Germany.
Joana
J
Schönberger
Department of Prosthodontics, Munich Dental School, Goethestr. 70, 80336, Munich, Germany.
Kurt-Jürgen
KJ
Erdelt
Hürzeler/Zuhr Private Practice, Rosenkavalierplatz 18, 81925, Munich, Germany.
Daniel
D
Bäumer
Department of Prosthodontics, Munich Dental School, Goethestr. 70, 80336, Munich, Germany. florian.beuer@charite.de.|Department of Prosthodontics, Charité UniversityMedicine Berlin, Assmannshauserstrasse 4-6, 14197, Berlin, Germany. florian.beuer@charite.de.
Florian
F
Beuer
D017076:Computer-Aided Design; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003779:Denture Design / Q000379:methods*; D003830:Denture, Partial, Fixed; D066298:In Vitro Techniques; D008422:Materials Testing; D003765:Models, Dental; D015040:Zirconium / Q000737:chemistry*
D003764:Dental Materials; D015040:Zirconium; C028541:zirconium oxide
Computer-aided design/computer-aided manufacturing; Fixed dental prosthesis; High-translucent zirconia; Marginal and internal fit; Pre-sintered zirconia