A Randomized Clinical Trial of Monolithic Single-Tooth Crowns: 1-Year Preliminary Results.

PURPOSE: To investigate the clinical results of single-tooth ceramic crowns in the posterior region produced from three different monolithic materials. MATERIALS AND METHODS: A total of 36 posterior single-tooth crowns were fabricated from lithium silicate glass-ceramic (LSGC; n = 12), lithium disilicate glass-ceramic (LDGC; n = 12), and polymer-infiltrated ceramic network (PICN; n = 12) in 27 patients. Restorations were evaluated for prosthetic and periodontal criteria at baseline (0) and after 6 and 12 months. Prosthetic evaluation was performed according to the modified United States Public Health Service (USPHS) criteria, and probing depth (PD), clinical attachment level (CAL), gingival bleeding time index (GBTI), and gingival (GI) and periodontal indices (PI) were evaluated in the periodontal assessment. Friedman and Kruskal-Wallis tests were used for statistical analyses (P = .05). RESULTS: All restorations were evaluated according to survival and success rates. No dropouts occurred. The survival rate of all three materials was 100% after 1 year. However, in the PICN group, a statistically significant difference was found between baseline and 12 months for color match (from A to B) and surface texture (from A to C; P < .001). CONCLUSIONS: Although long-term clinical follow-up periods are needed, all three ceramics showed clinically acceptable survival and success rates over 1 year. The ceramics evaluated in the present study could be preferred for single-tooth full-crown restorations in the posterior region.

Effects of Surface Treatments and Cement Type on Shear Bond Strength between Titanium Alloy and All-Ceramic Materials.

This study aimed to evaluate the effects of surface treatments and resin cement on the adhesion of ceramic and ceramic-like materials to titanium. A total of 40 specimens (5 mm diameter) of each material (lithium disilicate glass ceramic (LDGC-IPS e.maxCAD), lithium silicate glass ceramic (LSGC-VITA Suprinity) and a polymer-infiltrated ceramic network (PICN-Vita Enamic)) were fabricated using CAD/CAM technologies. In total, 120 titanium (Ti) specimens were divided into 12 groups, and half of the titanium specimens were tribochemically coated using CoJet. The titanium and all-ceramic specimens were cemented using either Self-curing adhesive cement (SCAC-Panavia 21) or a Self-curing luting composite (SCLC-Multilink Hybrid Abutment). After 5000 cycles of thermal aging, the shear bond strength (SBS) test was conducted using a universal testing machine. The failure modes of the specimens were analyzed using stereomicroscopy, and additionally, the representative specimens were observed using Scanning Electron Microscopy. ANOVA was used for the statistical analysis (p < 0.05). The post-hoc Duncan test was used to determine significant differences between the groups. The mean SBS values (mean ± STD) ranged from 15 ± 2 MPa to 29 ± 6 MPa. Significantly higher SBS values were acquired when the titanium surface was tribochemically coated (p < 0.05). The SCLC showed higher SBS values compared to the SCAC. While the LDGC showed the highest SBS values, the PICN presented the lowest. The tribochemical coating on the cementation surfaces of the titanium increased the SBS values. The specimens cemented with the SCLC showed higher SBS values than those with the SCAC. Additionally, the SCLC cement revealed a more significant increase in SBS values when used with the LDGC. The material used for restoration has a high impact on SBS than those of the cement and surface conditioning.