A systematic review on the accuracy of zirconia crowns and fixed dental prostheses

Abstract

Purpose: The aim of this study was to review the fit and assess the accuracy of tooth-supported single and multi-unit zirconia fixed dental prostheses. Background: The fit of zirconia restorations has been reported in several studies, but the accuracy of the manufacturing process is seldom discussed or used when drawing conclusions on the fit. Materials and methods: A literature search of articles published in PubMed between 2 March 2013 and 1 February 2018 was performed using clearly defined inclusion and exclusion criteria. 841 articles were found and 767 were excluded after screening the title and abstract. After fulltext analysis another 60 articles were excluded which left 14 articles to be included for data extraction. Fit was the mean of distances reported in the studies and accuracy was the fit minus the pre-set spacer Results: For marginal gap of single crowns and multi-unit FDPs combined, the fit was 83 lm and the accuracy was 59 lm. The internal gap fit was 111 lm and the accuracy 61 lm. For the total gap, the fit was 101 lm, and the accuracy of the zirconia restorations was 53 lm. Conclusions: Within the limitations of the present systematic review the fit of zirconia single crowns and multi-unit FDPs may be regarded as clinically acceptable, and the accuracy of the manufacturing of zirconia is $60 lm for marginal, internal, and total gap. Also, digital impressions seem to be associated with a smaller gap value.

In Vitro Study of Comparative Evaluation of Marginal and Internal Fit between Heat-Pressed and CAD-CAM Monolithic Glass-Ceramic Restorations after Thermal Aging

“…Several studies found in literature have evaluated the marginal gap between 100–200 µm and the internal gap from 200–300 µm for the cemented restorations [ 60 , 61 , 62 , 63 ]. These values are clinically acceptable.…”

Marginal fit of full contour monolithic zirconia in different thicknesses and layered zirconia crowns

“…There are various methods for measuring marginal adaptation, the most frequent ones are direct microscopic view, cross-section, and replica techniques. [ 20 ] This study evaluated the marginal gap by using a direct microscopic view of the non-cemented specimen on a die. This technique is noninvasive and the marginal gap could be measured in numerous points; nonetheless, the internal gap could not be assessed.…”

“…Marginal fit is affected by several factors such as different preparation designs, fabrication methods, sintering techniques, and CAD-CAM systems. [ 20 ] One of the influencing factors is the material thickness. [ 21 22 ] Controversies exist about the effect of zirconia thickness on the marginal fit of zirconia-based crowns.…”

Preliminary Study on the Assessment of the Marginal Fit of Three-Dimensional Methacrylate Oligomer Phosphine Oxide Provisional Fixed Dental Prostheses Made by Digital Light Processing

“…One of the most important factors in relation to clinical behavior and survival in tooth-borne dental prostheses is marginal fit [6]. Marginal fit is related to the materials and manufacturing techniques of choice.…”

“…Manufactured imperfections may result from a poor manufacturing process and the materials used for their confection. Lack of fit can create gaps leading to technical or biological complications [6,7].…”