Marginal Fit of Implant-supported All-Ceramic Zirconia Frameworks

Abstract

Objective: This study evaluated the effect of fabrication techniques and cyclic loading on the vertical marginal fit of implant-supported FPD frameworks. Methods: Thirty implant supported 3-unit FPD frameworks were fabricated on a model system, divided into three equal groups (n=10). The first group (control) was constructed from base metal alloy and the other two test groups were constructed from All-ceramic Zirconia using CAD/CAM Cerec III system and copy milling (Zirconzahn) system. A cyclic load of 200 N was applied to each framework for up to 50,000 cycles. Linear measurements were made in micrometers (µm) of the vertical gap between the framework and implant-supported abutment at 16 predetermined points before and after cyclic loading. The frameworks were viewed using SEM to inspect any fractographic features. One way analysis of variance (ANOVA) was performed to compare the marginal discrepancy values of the control and the two test groups and for each group; T-test was applied to determine whether significant changes in the fit were observed after cyclic loading. (α=0.05). Results: CAD/CAM group showed significantly higher marginal gap mean values (80.58 µm) than Zirkonzahn and control groups (50.33 µm and 42.27 µm respectively) with no significant difference while, after cyclic loading, CAD/CAM group recorded the highest marginal gap mean value (91.50 ± 4.260 µm) followed by control group (72.00 ± 2.795 µm) while Zirconzahn 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. Marginal chip was observed in one of the CAD/CAM ceramic frameworks. Conclusions: 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 while; significant changes were found in the metal frameworks.

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

“…Thus the null hypothesis was rejected. These results are in accordance with previous studies (23)(24)(25)(26) .…”

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

“…The MD analyzed between the abutment replicas and suprastructures are similar to those reported in previous studies at both OST and FFT 14,29,36 for CAD/CAM elaborated Cr-Co frameworks.…”

“…Different environmental 27 and stability factors of the scanning surfaces 28 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, 29,30 morphology and material of the scanbodies, 27 and environmental conditions. 1 The outcome analysis of the present study, using the same scanbodies material and morphology, in the same environmental conditions, revealed a clear trend toward greater angular error the greater the number of implants within the suprastructure.…”

“…32,33 Evaluation of the abutment/implant interface with microscopy, SEM or OM, allows taking direct measurements over photomicrographs by using different amplification scales. 14,34,35 Many studies 2,29,[32][33][34][35][36] have used SEM and/or OM for the evaluation of discrepancy between structures,…”

Accuracy of self-perforating impression tray for maxillary dental implant

“…[16][17][18][19][20][21][22][23] With this regard, gap measurements are commonly used to evaluate the fit of implants; hence, most studies use the gap width to evaluate the marginal discrepancy. 1,9,24,25 Thus, the aim of this study was to evaluate the accuracy of the self-perforating tray for taking an implant impression of the edentulous maxilla when compared with the conventional pick-up technique.…”