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Objective: To compare the bond strength of monolithic CAD-CAM materials to resin cement using different surface treatment methods. Materials and Methods: Lithium disilicate glass ceramic (IPS e-max CAD), zirconia-reinforced lithium silicate ceramic (Vita Suprinity), resin nanoceramic (Lava Ultimate), and hybrid ceramic (Vita Enamic) were used. Five groups of CAD-CAM blocks were treated as follows: control (C), HF etching (HF), HF etching + silanization (HF + S), sandblasting (SB), and sandblasting + silanization (SB + S). After surface treatments, SEM analyses were conducted. Specimens were cemented with self-adhesive resin cement (Theracem) and stored in distilled water at 37°C for 24 h. Shear bond strength (SBS) was measured, and failure types were categorized. Results were analyzed using two-way ANOVA and the post-hoc Tukey test. Results: Statistical analysis revealed significant differences between SBS values obtained for different surface treatments and CAD-CAM block types ( P < .001). Among the CAD-CAM materials, the highest SBS was reported in the HF + S group for Vita Enamic. Although IPS e.max CAD, Vita Suprinity, and Vita Enamic showed higher bond strength when treated with HF + S, Lava Ultimate has the highest bond strength value when treated with SB + S. Conclusions: The bond strength of CAD-CAM materials was influenced by surface treatment. Additionally, silanization significantly improved the bond strength of all materials except Lava Ultimate.

Objective. The purpose of this study was to examine the optical properties of translucent zirconia with different thickness during multiple firings. Materials and Methods. Three different types of translucent zirconia (Vita YZ HT (HT), Vita YZ ST (ST), Vita YZ XT (XT)) with thickness of 0.5, 1, and 1.5 mm were used in the study. 180 disk-shaped specimens ( n = 10 ) were prepared from preshaded and nonshaded blocks. The coloring liquid (A2, Vita Shade Liquid) was applied with a synthetic nylon brush in the nonshaded group. Then, the specimens were then subjected to 1, 3, and 5 firing times. After consecutive firings, color differences ( Δ E ) and translucency parameter ( TP ) were measured. Statistical analysis was carried out by using repeated measure ANOVA followed by Tukey test. Results. ANOVA analysis reveals that TP and Δ E were significantly affected by the repeated firings. The highest TP was seen in 0.5 mm XT specimen. For all specimens, TP decreases from 1st to 3rd firing cycles, despite TP increases from 3rd to 5th firing cycles. Although there is a significant change in TP values in 0.5 mm thickness, there is no significant change between firing cycles for 1 and 1.5 mm thickness specimens. The highest Δ E value was observed for shaded specimens between 1st and 5th firings. Δ E values were not significantly different between 1 and 3 firings. Conclusions. Changes in thickness and repeated firings of zirconia specimens affected final color and translucency of zirconia specimens. HT blocks are more affected by consecutive firings than ST and XT blocks. Δ E increased as the thicknesses decreased for both types of translucent zirconia specimens tested.

Aim. The purpose of this study is to investigate the effects of hydrofluoric acid and one-component ceramic primer and silane (Monobond Etch and Prime (MEP)) applications on lithium disilicate glass ceramics and zirconium-infiltrated lithium silicate glass ceramics, as well as the effect of ultrasonic and phosphoric acid surface washing methods on bond strength. Materials and Method. A total of 240 ceramic samples were prepared using two different CAD-CAM material blocks with a thickness of 2 mm made of lithium disilicate glass-ceramic (IPS e.max CAD) and zirconium-infiltrated lithium silicate glass ceramic blocks (Celtra Duo). The samples were cemented to the composite discs (Tetric N-Ceram) after two different acid treatments, and surface washing processes were applied to them. As such, 24 groups were formed, each with two different acid applications, three different washing processes, two different CAD-CAM blocks, and two different aging procedures ( n = 10 ). Following the application of the acid, different washing processes are used. These were HF acid and washing only (HF + W), HF acid and ultrasonic washing (HF + US), HF acid and phosphoric acid (HF + PA), MEP with washing only (MEP + W), MEP and ultrasonic washing (MEP + US), and MEP and phosphoric acid (MEP + PA). The composite discs were cemented with dual cure adhesive cement (Multilink Automix) after the determined surface treatments were applied to the blocks. After surface applications, SEM analysis was conducted. Following exposure to two different thermal procedures, long-term (TL) and short-term (TS), bond strengths were measured using an Instron universal test device. SPSS version 23.0 software was used to perform the statistical analyses. Histogram graphs and the Kolmogorov-Smirnov/Shapiro-Wilk test were used to assess the variables’ conformity to the normal distribution. Results. The bond strength values of TS and TL in the Celtra Duo block were significantly higher than those in the e.max CAD block ( p < 0.05 ). The TS-TL bonding strength value difference in the e.max CAD block was significantly higher than the surface measurements in the Celtra Duo block. While the highest bond strength value HF + US for TS in e.max CAD was 20.07 ± .31 , the values of HF + US in Celtra Duo were significantly higher in terms of TL values when compared to other groups. Conclusion. Celtra Duo material demonstrated higher bond strength values after a short and long thermal cycle than e.max CAD material. In general, groups bonded with HF were less affected by the thermal cycle than groups treated with MEP.

Purpose. The purpose of this study was to evaluate the effect of veneering and aging on the translucency of newly introduced extra and high translucent zirconia with different thickness. Materials and Methods. One hundred forty disk-shaped specimens were fabricated from two translucent zirconia blocks (VITA YZ XT and VITA YZ HT), and they are milled with CAD/CAM system. Then, specimens were divided into nonveneered (XT, HT) and veneered groups (XTV, HTV). Nonveneered groups were prepared with four different thicknesses (0.5-1-1.5-2 mm). Veneered groups were divided into three subgroups ( n = 10 ) for veneering with base dentin ceramic with thicknesses of 0.5 + 0.5 , 0.5 + 1 , and 0.5 + 1.5   mm . A spectrophotometer was used to calculate the translucency parameter (TP) and contrast ratio (CR) of all specimens before and after aging. Statistical analysis was performed using 3-way ANOVA and Tukey HSD tests ( p < 0.05 ). Results. TP values were significantly affected by thickness of specimens ( p < 0.001 ). VITA YZ XT was significantly found more translucent than VITA YZ HT. The highest translucency was observed in the XT-0.5 mm group. There is no significant difference between translucency of the veneered and nonveneered groups in the same thickness for XT. On the contrary, veneering significantly affected translucency of HT. TP values significantly decreased after aging for all groups. After aging, translucency value difference before and after aging was the highest in the XT-0.5 mm group whereas the HTV-2 mm group showed the lowest difference after aging. TP decreased significantly as thickness of specimen increases regardless of the material type. Extra translucent and nonveneered zirconia groups are more prone to hydrothermal aging. Conclusions. The translucency parameter of zirconia ceramics was significantly influenced by both material type and veneering. Also, extra translucent and nonveneered zirconia groups are more susceptible to hydrothermal aging.

In our University's Vocational School of Health Services, there is a Dental Prosthesis Technology program, which provides training to train dental technicians who enable the laboratory work of fixed and removable prostheses according to the treatment planned by the dentist. In the dental prosthesis technology program, in addition to the theoretical courses, practical courses are also given. In this study, it is aimed to evaluate the demographic data of students enrolled in a state university, the efficiency of the practice courses and the students' perspectives on the profession. Our study group consisted of 61 second year students from the University of Health Sciences Department of Dental Services, Dental Prosthesis Technology Program. All of the students voluntarily participated in the survey created via Google Forms. In our study, students' application efficiency was measured as practise evaluation score (PES). In addition, questions about job anxiety levels and career planning after graduation were asked. There was no statistically significant difference between the distributions of career planning according to the reason for choosing the department (p>0.050). There is no statistically significant relationship between the age of the students and their anxiety about finding a job when they graduate (p=0.257). According to gender, students' anxiety about finding a job when they graduate differs (p=0.031). There was no significant difference between the application evaluation scores of the students according to their career planning (p>0.050). As a result of the study, the anxiety level of finding a job after graduation in female students was found to be higher than that of male students. The students stated that the reason for their low PES was the limited time given.

İmplant destekli protezler implantlar tarafından tutuculuk sağlarken ağızdaki dokulardan destek alırlar. Overdenture protezler, çene ilişkisinin uygun olmadığı ve kemik yıkımının fazla olduğu hastalarda hijyeni sağlamada kolaylık sağlaması, ekonomik olması ve bir yandan da estetiğin sağlanmasına olanak tanıdığı için tercih edilmektedir. Son yıllarda hasta memnuniyetine verilen önem artmış ve bunu sağlamanın yolları geliştirilmeye başlanmıştır. Çoğu vaka değerlendirildiğinde overdenture protezlerin geleneksel protezlere göre daha iyi bir seçenek olduğu görülmüştür. Bunun sebeplerine örnek olarak klinik yapım aşamasının daha kısa olması sayesinde yaşlı hastalarda daha güvenilir bir yol olması, estetik üstünlük, çiğneme fonksiyonunun daha iyi olması ,protez stabilitesinin üstünlüğü ve daha az çiğneme güçlüğünün yaşanması verilebilir. İmplant destekli overdenture protezlerde farklı ataşman sistemleri kullanılmakta olup hekimlerin karar vermekte zorlandığı konuların başında gelmektedir. Seçim yapılırken hastanın ağız hijyenine verdiği önem, implantların arasındaki mesafe, anatomik faktörler, destek sayısı ve kretteki mevcut dağılımı, kretin şekli, kemik yıkım miktarı, tutuculuk ihtiyacı, hastanın psikolojik durumu, beklentileri ve ekonomik durumu dikkate alınmalıdır.

Aim: The purpose of this study is to compare the marginal fit of crowns manufactured using different CAD/CAM materials on 2 different types of finish line design. Material and method: Tooth preparations were made by creating 2 different finish lines (rounded shoulder, chamfer) on an acrylic mandibular second premolar model. Impressions were taken on each preparation using polyvinylsiloxane impression material, and blocks with three different compositions including lithium disilicate (LDS), zirconia-reinforced lithium silicate (ZLS), and monolithic zirconia (MZ) (UP.CAD, Celtra Duo, and VITA YZ HT) were produced using a CAD/CAM (computer-aided-design and computer-aided-manufacturing) milling device (VHF R5) (n=10). The marginal gap values of the crown restorations were measured by the same operator using a stereomicroscope (LEICA DVM6). Histogram plots and the Kolmogorov-Smirnov test were used to test the normality of the distributions of the variables. The non-normally distributed (nonparametric) variables were compared using the Mann-Whitney U test for two groups and the Kruskal-Wallis test for more than two groups. Results: The marginal gap values were compared between finish line designs separately for each material. Accordingly, the marginal gap values of the rounded shoulder finish line were smaller than those of the chamfer finish line in all materials. The marginal gap values were also compared among the materials separately for each finish line type. Accordingly, the marginal gap values of the VITA YZ HT material were smaller than those of the Celtra Duo (ZLS) and UP.CAD (LDS) materials for both finish line designs. There was no significant difference between Celtra Duo and UP.CAD. Conclusion: The finish line design is a factor that affects marginal fit. Monolithic zirconia is more appropriate for clinical use as it shows a better marginal fit compared to LDS and ZLS.