Influence of marginal fit and cement types on microleakage of all-ceramic crown systems

Abstract

The purpose of this study was to evaluate the effects of both marginal fit and cementing with different luting agents on the microleakage of all-ceramic crown systems. Thirty-six extracted upper central incisors were prepared for full-coverage crowns and were divided into three groups. Group 1: CAD/CAM-fabricated ZrO2, Group 2: Heat-pressed lithium-disilicate, and Group 3: Cast Cr-Co copings as the control group. Copings were made following standard techniques, and groups were assigned cementation with either self-adhesive resin cement (A) or glass-ionomer luting cement (B). The specimens were subjected to thermocycling, immersed in basic fuchsin solution, sectioned mesiodistally and buccolingually. The surface of each section was digitally photographed under a stereomicroscope. Microleakage was scored using a five-point scale, and the marginal gap was measured using image analysis software. Data were statistically analyzed using 2-way ANOVA, Kruskal-Wallis, and Mann-Whitney U tests (α: 0.05). The marginal discrepancy of each group was 82.7 ± 7 µm, 92.6 ± 4 µm and 96.5 ± 7 µm respectively. Group 1 showed significantly smaller gaps than Group 3 (P = 0.042). Self-adhesive resin cement (A) showed a lower level of microleakage than glass-ionomer luting cement (B) in all groups (P = 0.029). Microleakage scores of '0' were 83% for 1A, 50% for 1B, 50% for 2A, 16% for 2B, 33% for 3A and none for 3B. Marginal discrepancy and cement type both had significant effects on microleakage. Lower levels of microleakage were recorded with self-adhesive resin cement, while CAD/CAM-fabricated ZrO2 copings showed smaller marginal discrepancy and less microleakage in comparison to cast Cr-Co.

The marginal fit of E.max Press and E.max CAD lithium disilicate restorations: A critical review

“…Measurements of the marginal gap were achieved after sectioning the specimens and digital photography under a stereomicroscope at 50× magnification. The mean marginal gap was 92.6±4 microns with slightly higher values for the glass ionomer cement group, but with no significant differences 36) . The variance in this study is not clear from the original article, if it is a standard deviation or a standard error.…”

“…Yuksel and colleagues 36) studied the marginal fit of E.max press crowns (n=12 crowns) with two types of luting cements (Glass ionomer cement (n=6), Self-adhesive resin cement (n=6). Measurements of the marginal gap were achieved after sectioning the specimens and digital photography under a stereomicroscope at 50× magnification.…”

A 3-dimensional accuracy analysis of chairside CAD/CAM milling processes

“…[14][15][16][17][18] The adaption of the restoration to the preparation with regard to marginal and internal fit has been found to be clinically reliable in numerous studies. [19][20][21][22][23] mm. 24 Relatively large internal gaps can result from the milling process, 25 but gaps of up to 150 mm are clinically tolerable.…”

Trueness of four different milling procedures used in dental CAD/CAM systems

“…Imperfections at the margins can lead to inflammation of gingival tissue [13]. Increased marginal gap size can result in plaque accumulation and increased potential for microleakage [9,14]. In clinical studies, a high rate of secondary caries has been attributed to marginal deficiency [15,16].…”