Marginal Fit of Implant-Supported All-Ceramic Zirconia Frameworks

Abstract

This study evaluated the effect of fabrication techniques and cyclic loading on the vertical marginal fit of implant-supported fixed partial denture (FPD) frameworks. Thirty implant-supported 3-unit FPD frameworks were fabricated on a model system, divided into 3 equal groups (n = 10). The first group (control) was constructed from base metal alloy; the other 2 test groups were constructed from all-ceramic zirconia using a computer-aided design/computer-aided manufacturing (CAD/CAM) Cerec 3 system and a copy milling (Zirkonzahn) system. A cyclic load of 200 N was applied to each framework for up to 50,000 cycles. Linear measurements were made in micrometers of the vertical gap between the framework and the implant-supported abutment at 16 predetermined points before and after cyclic loading. The frameworks were viewed using scanning electron microscopy to inspect any fractographic features. One-way analysis of variance was performed to compare the marginal discrepancy values of the control and the 2 test groups and for each group; a t test was applied to determine whether significant changes in the fit were observed after cyclic loading (α = 0.05). The CAD/CAM group showed significantly higher marginal gap mean values (80.58 μm) than the Zirkonzahn and control groups (50.33 μm and 42.27 μm, respectively) with no significant difference. After cyclic loading, the CAD/CAM group recorded the highest marginal gap mean value (91.50 ± 4.260 μm) followed by control group (72.00 ± 2.795 μm); the Zirkonzahn group recorded the lowest marginal gap (65.37 ± 6.138 μm). Cyclic loading significantly increased the marginal gap mean values in the control group only. A marginal chip was observed in one of the CAD/CAM ceramic frameworks. Within the limitations of this study, the fabrication technique influenced the marginal fit of the implant-supported 3-unit FPD frameworks. Cyclic loading failed to change the fit of all-ceramic zirconia frameworks, whereas significant changes were found in the metal frameworks.

Marginal and internal fit of CAD/CAM frameworks in multiple implant‐supported restorations: Scanning and milling error analysis

“…Evaluation of the abutment/implant interface with microscopy, SEM or OM, allows taking direct measurements over photomicrographs by using different amplification scales . Many studies have used SEM and/or OM for the evaluation of discrepancy between structures, reporting similar results to the present study. Microscopy is an excellent method for analyzing MD, but its main drawback is the need to section the framework to find ID.…”

“…Different environmental and stability factors of the scanning surfaces may make the process more accurate than intraoral scanning. However, many studies have described variables that could cause error, such as the number, angulation, and distance between implants, morphology and material of the scanbodies, and environmental conditions…”

Clinical Advantages and Limitations of Monolithic Zirconia Restorations Full Arch Implant Supported Reconstruction: Case Series

“…Full arch implant supported restorations have been documented to have high success rates [1–6]. Many combinations of materials have been used for this type of restorations such as metal alloy-acrylic, metal alloy-composite, and metal alloy-ceramic [1, 5, 7].…”

“…The fabrication of the structure in one block reduces breakage possibilities and avoids chipping [4, 5]. Moreover, high strength, minimal occlusal adjustment, and accuracy are some of its advantages [3, 4, 6, 13]. …”

Influences of multiple firings and aging on surface roughness, strength and hardness of veneering ceramics for zirconia frameworks

“…They all exhibit compositional and microstructural differences, depending on the type of ceramic. Although low-temperature degradation of zirconia, the chipping of veneering ceramics, the design of the framework, and the fit of the prosthesis have attracted extensive attention from the researchers, there have not been many studies concerning the aging of these veneering ceramics [23][24][25][26][27][28][29][30][31][32].…”