A comparison of the marginal vertical discrepancies of zirconium and metal ceramic posterior fixed dental prostheses before and after cementation

Marginal Accuracy and Fracture Strength of Implant Supported Zirconia Copings Constructed Using CAD/CAM and MAD/MAM Techniques

“…There are some variations in opinions regarding the value for clinically acceptable margin adaptation. Some studies reported values between 40 and 120μm (17)(18)(19) . Other studies reported wider marginal discrepancy up to 180 μm (20)(21)(22) .…”

SEM evaluation of the precision of fit of CAD/CAM zirconia and metal-ceramic posterior crowns

“…The process of fabricating the zirconia cores consisted of scanning and digitizing the steel dies with the corresponding scanners: Procera Forte (Nobel Biocare) for NobelProcera Zirconia, Lava Scan (3M ESPE) for Lava Zirconia and InEos (Sirona Dental, Bensheim, Germany) for VITA In-Ceram YZ restorations, as previously described 9) . The cores of the three zirconia systems were prepared with a wall thickness of 0.5 mm, and a cement gap of 50 μm.…”

“…Due to the morphology of the crowns, the samples were mounted on a customized metallic support at an angle of 25 degrees in order to situate the interface perpendicularly to the optical axis of the microscope, thus guaranteeing repeatable projection angles 17,18) . To standardize the marginal analysis, the measuring areas were previously marked with an indelible marking pen (Lumocolor permanent, Staedtler Mars, Nürnberg, Germany) at the same point in the middle of the buccal and lingual surfaces for each crown [7][8][9] . The data were captured and the images digitized using the software INCA suite 4.04 (Oxford Instruments Analytical, Oxford, UK).…”

“…Poor seals may give rise to a series of biological, periodontal, esthetic or mechanical complications, which may present singly or jointly [5][6][7] . However, no consensus has yet been reached on the clinically acceptable dimension of the interface, ranging the values reported in the literature from 50-200 μm [7][8][9] , and most researchers continue to use the criteria established by McLean and von Fraunhofer 10) . Several studies demonstrated that the final adaptation of the restorations depends on several factors such as finish line, manufacturing technique, porcelain firing and cementing 9,[11][12][13] .…”

“…However, no consensus has yet been reached on the clinically acceptable dimension of the interface, ranging the values reported in the literature from 50-200 μm [7][8][9] , and most researchers continue to use the criteria established by McLean and von Fraunhofer 10) . Several studies demonstrated that the final adaptation of the restorations depends on several factors such as finish line, manufacturing technique, porcelain firing and cementing 9,[11][12][13] . Different methods are used to analyze the marginal fit of the restorations, but there is an absence of standardization in the methodology 14) .…”