PURPOSEThe purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns.MATERIALS AND METHODSA master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at 37℃ for 24 hours, and then they were thermocycled (TC, 5000×, 5-55℃) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (α=.05).RESULTSFmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01).CONCLUSIONComposite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CAD-CAM technique offers more advantages than the direct technique.
Color changes were observed in each evaluated material after accelerated aging. All CAD/CAM inlays became darker in appearance, more saturated, a little reddish, and more yellow.
Purpose: To investigate the effect of a 16% carbamide peroxide home bleaching agent on the ion elution of different esthetic restorative materials and to determine if the released ions exceed the minimal risk levels. Materials and Methods: Ceramic materials comprising a low-fusing porcelain (Vita VM7), lithium disilicate glass-ceramics (IPS e.max Press and IPS e.max CAD), zirconium substructure materials (IPS e.max ZirCAD and Vita In-Ceram YZ for InLab), and ceromers (Estenia and Tescera ATL) were chosen. Thirty disk-shaped specimens (2 mm thickness and 10 mm diameter) were fabricated from each material and then were divided into 3 experimental groups to receive one of the following solutions: acetic acid (positive control), a bleaching agent and distilled water (negative control) (n = 10/group). For the bleaching agent, the specimens were subjected to a 16% carbamide peroxide solution (VOCO Perfect Bleach) for 2 hours per day for 14 days. A 4% acetic acid solution was applied at 80°C for 16 hours according to the ISO 6872:2015 protocol and specimens of negative control group were immersed in distilled water for 16 hours. Ion elution measurements were conducted with inductively coupled plasma atomic emission spectroscopy (ICP-AES) after immersion in the solutions, and the weight loss of the materials was measured with a precision scale. Changes in the surface topography were investigated by a scanning electron microscopy (SEM).The results were evaluated using multivariate analysis of variance (MANOVA). Results: Among the specimens tested, the most ion elution was observed in the Tescera ATL group, and the least ion elution was observed in the e.max ZirCAD group in all solutions. Ion elution was found to be greater in the bleaching agent than in the acetic acid and distilled water groups. Sodium was the most released ion, and zinc and lithium were the least released among the elements tested. Conclusions: It should be noted that the bleaching-related ion release may exceed toxic doses even if restorative materials meet ISO 6872 standards, and the materials should be protected before home bleaching to prevent ion elution.
SUMMARY Objectives This study aimed to compare color change of porcelain laminate veneers fabricated with two lithium disilicate ceramics and a zirconia-reinforced lithium silicate ceramic material after luting with conventional dual-cure, amine-free dual-cure, or light-cure resin cements using artificial accelerated aging (AAA). Methods and Materials Ninety noncarious human maxillary central incisors were embedded in autopolymerizing acrylic resin blocks to prepare conventional laminate veneers with incisal coverage. Prepared teeth were randomly divided into 3 groups (n=30) to fabricate laminate veneer restorations using: (1) lithium disilicate ceramic, (2) lithium disilicate ceramic with high-density micronization, and (3) zirconia-reinforced lithium silicate ceramic. Impressions of the preparations were taken with a laboratory scanner. Acquired 3D images were processed into a surface tessellation language file. Data were exported for 3D printing on a printer, and laminate veneers were printed in castable wax resin. Ceramic veneers were heat-pressed after investment according to the manufacturer’s recommendations and further divided into three groups (n=10) according to luting cement type: (1) light-cure resin cement, (2) amine-free dual-cure resin cement, and (3) conventional dual-cure resin cement. Color measurements were performed from the middle of each specimen with a spectrophotometer before and after AAA for 300 hours with a total energy of 150 kJ/m2. Color changes were calculated with the CIEDE 2000 (ΔE00) formula. Color differences were assessed using two-way analysis of variance (ANOVA) (α=0.05), and the paired t-test was used to compare the L*, a*, and b* parameters in each group before and after aging. Results There were no significant differences between the ceramic groups (p>0.05). The color changes of the materials ranged from 2.26 to 3.13. All materials were above the clinically acceptable limit (ΔE00>1.8). The conventional dual-cure resin cement group showed more color change (p>0.05). Conclusions Color changes were observed in all porcelain laminate veneers after artificial accelerated aging. The zirconia-reinforced lithium silicate veneers showed similar color changes as lithium disilicate veneers; the amine-free dual-cure resin cement showed a similar color change as light-cure resin cement after aging.
PURPOSE This study aimed to compare the effect of different surface treatments and luting agent types on the shear bond strength of two ceramics to commercially pure titanium (Cp Ti). MATERIALS AND METHODS A total of 160 Cp Ti specimens were divided into 4 subgroups (n = 40) according to surface treatments received (control, 50 µm airborne-particle abrasion, 110 µm airborne-particle abrasion, and tribochemical coating). The cementation surfaces of titanium and all-ceramic specimens were treated with a universal primer. Two cubic all-ceramic discs (lithium disilicate ceramic (LDC) and zirconia-reinforced lithium silicate ceramic (ZLC)) were cemented to titanium using two types of resin-based luting agents: self-cure and dual-cure (n = 10). After cementation, all specimens were subjected to 5000 cycles of thermal aging. A shear bond strength (SBS) test was conducted, and the failure mode was determined using a scanning electron microscope. Data were analyzed using three-way ANOVA, and the Tukey-HSD test was used for post hoc comparisons ( P < .05). RESULTS Significant differences were found among the groups based on surface treatment, resin-based luting agent, and ceramic type ( P < .05). Among the surface treatments, 50 µm air-abrasion showed the highest SBS, while the control group showed the lowest. SBS was higher for dual-cure resin-based luting agent than self-cure luting agent. ZLC showed better SBS values than LDC. CONCLUSION The cementation of ZLC with dual-cure resin-based luting agent showed better bonding effectiveness to commercially pure titanium treated with 50 µm airborne-particle abrasion.
No abstract
Yayına Kbul ÖZ Farklı CAD/CAM inlay restorasyonların yapay yaşlandırma sonrası kırılma dayanımlarının incelenmesi Amaç: Bu çalışmanın amacı, farklı materyaller kullanılarak bilgisayar destekli tasarım/bilgisayar destekli üretim (CAD/CAM) ile üretilen inley restorasyonların hızlandırılmış yapay yaşlandırma sonrasında kırılma direncini karşılaştırmaktır. Gereç ve Yöntemler: Kırk adet mandibular molar dişe sınıf I inlay preparasyonu yapıldı. Dişler, kullanılan malzeme tipine göre dört gruba (n = 10) ayrıldı: feldspatik-seramik (CEREC Blocks); lösit bazlı cam seramik (IPS Empress CAD); rezin nano-seramik (Lava Ultimate); ve kontrol (sağlam dişler). Dijital ölçüler elde edildikten sonra restorasyonlar CAD/CAM ile tasarlandı ve üretildi. İnlay restorasyonlar, dual polimerize bir rezin siman (Rely X Ultimate) kullanılarak inlay boşluklarına simante edildi ve bir hafta boyunca 37°C'de distile su içinde saklandı. Tüm örnekler daha sonra 300 saat boyunca hızlandırılmış ultraviyole yaşlandırmasına maruz bırakıldı. Son olarak, kırılıncaya kadar örneklere bir sıkıştırma yükü uygulandı. İstatistiksel analiz Tek Yönlü ANOVA ve Tukey HSD testi (α= 0,05) kullanılarak yapıldı. Bulgular: Grupların ortalama kırılma dayanımları sırasıyla şu şekildedir: Kontrol (1555,3±412,2 N) > Lava Ultimate (1525±394 N) > IPS Empress CAD (1364,3±545,6 N) > CEREC (1231,9±412,2 N). Ancak grupların ortalama kırılma dayanımları arasında istatistiksel bir fark bulunamadı (P>0,05). CEREC ve IPS Empress CAD gruplarının %50'si ve Lava Ultimate grubunun %60'ı tamir edilebilir kırık tipi sergiledi. Sonuç: Kullanılan materyal tipi, inley ile restore edilmiş molar dişlerin kırılma direncini etkilememiştir ve inley restorasyonlar restore edilen dişlerin gücünü zayıflatmamıştır. Bu nedenle, test edilen tüm materyaller posterior bölgede kullanılabilir.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.