title: 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.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Ankara University, Ankara, Turkey. dtyuksel@gmail.com
authors.forename: Ece
authors.initials: E
authors.lastname: Yüksel
authors.forename: Ali
authors.initials: A
authors.lastname: Zaimoğlu
mesh_terms: D000704:Analysis of Variance; D002484:Cementation / Q000379:methods; D002516:Ceramics / Q000737:chemistry*; D003442:Crowns; D003738:Dental Cements / Q000737:chemistry*; D003763:Dental Leakage / Q000209:etiology*; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry; D008422:Materials Testing; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D003738:Dental Cements; D003764:Dental Materials