Asli Secilmis

Aims: Temporomandibular disorders (TMDs) are multifactorial conditions influenced by biological and psychosocial factors. In this study, postgraduate dental students were evaluated for TMD. Anxiety and depression were analyzed in relation to TMD. Methods: In this cross-sectional study, data were obtained from 214 postgraduate dental students. TMD severity was determined using the Fonseca Anamnestic Index (FAI). Levels of anxiety and depression were obtained with the Hospital Anxiety and Depression Scale (HADS). Differences between groups were analyzed using the Mann–Whitney U test and the chi-square test. Relationships among continuous variables were explored with Spearman correlation analysis. Multivariable logistic regression was applied to identify factors associated with TMD. The discriminative ability of the model was evaluated by receiver operating characteristic (ROC) curve analysis. Results: TMD were identified in 68.7% of the participants. Individuals with TMD exhibited significantly higher anxiety scores compared with those without TMD (p

This study aimed to evaluate the effect of a matrix metalloproteinase inhibitör (Baicalein) on the resin-dentin bond strength in ceramic cementation. The occlusal enamel of sixteen human mandibular wisdom teeth was cut, and glass matrix ceramic (Celtra Duo) overlays were prepared. The samples were randomly divided into four groups. The control group was cemented without pretreatment using total-etch dual-curing resin cement (Variolink N). In the dimethyl sulfoxide and baicalein groups, the solution was applied to the dentin after acid etching. Subsequently, the standard cementation process was continued. In the baicalein and ultrasonic agitation group, unlike the other two groups, after etching, the baicalein solution was applied, ultrasonic agitation was performed for 10 seconds, and agitation was carried out at each stage. The samples underwent thermal aging. Microbars were obtained by cutting the samples, and microtensile tests were conducted. The bond surface and the pretreated occlusal surface were observed using a scanning electron microscope. Shapiro-Wilk test, Kruskal-Wallis test and Dunn's multiple comparison test were applied for statistical analysis. The bond strength values of the control group were significantly higher than those of the other three groups. The use of dimethyl sulfoxide and/or baicalein solutions did not improve the bond strength to the ceramic and dentin for the total-etch dual-cure resin cement.

Purpose: To evaluate the bond strength of repair systems (Ceramic Repair, Clearfil Repair) to computer‐aided design/computer‐assisted machining (CAD/CAM) restorative materials (IPS e.max CAD, Vita Suprinity, Vita Enamic, Lava Ultimate).Materials and Methods: Thermally aged CAD/CAM restorative material specimens (5000 cycles between 5°C and 55°C) were randomly divided into two groups according to the repair system: Ceramic Repair (37% phosphoric acid + Monobond‐S + Heliobond + Tetric N Ceram) or Clearfil Repair (40% phosphoric acid + mixture of Clearfil Porcelain Bond Activator and Clearfil SE Bond Primer + Clearfil SE Bond + Filtek Z250). The resin composite was light‐cured on conditioned specimens. All specimens were stored in distilled water at 37°C for 24 hours and then additionally aged for 5000 thermal cycles. The shear bond strength test was performed using a universal testing machine (0.5 mm/min). Two‐way ANOVA was used to detect significance differences according to the CAD/CAM material and composite repair system factors. Subgroup analyses were conducted using the least significant difference post‐hoc test.Results: The results of two‐way ANOVA indicated that bond strength values varied according to the restorative materials (p < 0.05). No significant differences were observed between the CAD/CAM restorative materials (p > 0.05), except in the Vita Suprinity group (p < 0.05). Moreover, no differences were observed between the repair systems.Conclusions: Both the Clearfil and Ceramic repair systems used in the study allow for successful repairs.

Aim: The aim of this study was to evaluate the fracture strength of monolithic zirconia and fiber-reinforced composite (FRC) inlay-retained FPDs, both of which are cemented to the laser-etched cavity surfaces. Materials and Methods: Eighty freshly extracted sound human teeth were used. A premolar and a molar tooth were embedded in an autopolymerizing acrylic resin. Forty acrylic resin models were randomly divided into two groups including monolithic zirconia and FRC inlay-retained FPDs (n = 20). Then, these groups were divided into two subgroups according to conditioning of the cavity surfaces with or without Er:YAG laser etching. Monolithic zirconia inlay-retained FPDs were produced by an inLab MC XL milling device using monolithic zirconia blocks. Tescera™ Fiber Reinforcement Materials were used for the FRC inlay-retained FPDs. After 10.000 thermal cycles, fracture strength test was applied to the specimens. Results: The monolithic zirconia inlay-retained FPDs exhibited the highest fracture strength than the FRC inlay-retained FPDs. Fracture strength was increased with laser etching for both restorative materials (p < 0.05). Conclusion: Laser etching had positively effect on the fracture strength of the inlay-retained FDPs.

Objective: The aim of this in vitro study was to evaluate the effect of surface treatments on the shear bond strength of resin cements to zirconia. Material and methods: Sintered zirconia specimens (n = 192) were divided into four different surface treatment groups: control (no treatment); airborne-particle abrasion; glaze layer and hydrofluoric acid (HF) application, and hot etching solution application. Then, each group was divided into four subgroups (n = 12), and three different resin cements were applied to the zirconia surfaces. The shear bond strength value of each specimen was measured after 5000 thermo cycles. The failure types were examined with a stereomicroscope and the effects of the surface treatments were evaluated with a scanning electron microscope. Results were analyzed using analysis of variance and Tukey’s post hoc tests (α = 0.05). Results: The surface treatment and resin cement type significantly affected the bond strength results (p < 0.05). For all resin cements, the airborne-particle abrasion treatment increased the shear bond strength values (p < 0.05). The glaze layer & HF application increased shear bond strength values for all groups, except the Single Bond Universal-RelyX Unicem Aplicap group (p < 0.05). The surface roughness values of airborne-particle abraded specimens were similar to comparable values for specimens from the control group and the hot etching solution group (p > 0.05). The glaze layer & HF application group produced the highest surface roughness values (p < 0.05). Conclusion: The results of this study recommend using the appropriate combination of surface treatment and adhesive/silane coupling agent to achieve durable zirconia-resin bonding.

Objective: The aim of this in vitro study was to examine the color changes in resin cements polymerized under lithium disilicate glass ceramic material (IPS Empress 2). Material and methods: A pressable ceramic material (10 mm × 1 mm) placed between the curing unit tip and resin cement was used to simulate the impact of light transmission on restoration. Light-polymerized Variolink II, dual polymerized Variolink II, Multilink Automix, Clearfil Esthetic Cement, Panavia F 2.0, RelyX Veneer, and Nexus 3 resin cement specimens were polymerized by a high-power light-emitting diode curing unit (Demi). A spectrophotometer (Vita EasyShade) was used to measure the colorimetric values of the specimens. Color changes were determined by the CIEL*a*b color system. Total color differences ( ) of the resin cement specimen with or without the ceramic specimen were calculated. Analysis of variance, Tukey’s honestly significant difference and paired t-tests were used to analyze the data (α = 0.05). Results: There were significant differences among values with or without the ceramic specimen (p < 0.05). The light-polymerized Variolink II resin cement specimens induced the greatest color changes with or without the ceramic specimen ( = 14.21 and = 2.32). The values of all resin cements with the ceramic specimen were less than 2.5 and the Panavia F 2.0 specimens induced the smallest color changes ( = 0.95). Conclusions: Light polymerization of resin cements is a significant factor affecting the color of the final restoration, but lithium disilicate glass ceramics of 1-mm thickness appeared to have a masking effect on the color changes in resin cements.

Objective: This study aimed to evaluate the degree of conversion (DC) of two different resin cements polymerized under the monolithic zirconia specimens in different thicknesses and colors. Material and methods: Partially stabilized monolithic zirconia blocks (inCoris TZI) were cut into three different thicknesses (0.5, 1.0, and 2.0 mm) and the specimens were divided into four color groups (A1, A2, A3, and A4). The light transmittance of each specimen was measured. Panavia F 2.0 or Variolink N resin cement was applied into teflon mold and irradiated using the light emitting diode curing unit for 20 s under monolithic zirconia specimen (n = 10). The resin cement specimens were stored at room temperature under dry conditions. The DC of each specimen was measured by Fourier transform infrared-attenuated total reflection (FT-IR/ATR) spectroscopy after the 1st and 10th day. Data were analyzed with two-way analysis of variance (ANOVA), two-way repeated measures ANOVA, three-way repeated measures ANOVA, and the Tukey least significant difference (LSD) tests (α = 0.05). Results: The light-cure resin cement groups showed higher DC than the dual-cure resin cement groups (p < 0.05). The DC of both resin cements reduced with an increase in the thickness and darkening of the color of monolithic zirconia specimens. There was a statistically meaningful increase in the 10th-day values for dual-cure resin cement (p < 0.05), whereas there were no significant differences between the 1st- and 10th-day values for light-cure resin cement (p > 0.05). Conclusion: The use of light-cure resin cement can be suggested for the luting of monolithic zirconia restorations.

Objective: This study investigated the bond strength of two resin cements (Panavia F 2.0 and Multilink N) to different CAD/CAM materials: resin nanoceramic (RNC; Lava Ultimate), hybrid ceramic (HC; Vita Enamic), zirconia-reinforced lithium silicate ceramic (ZLDC; Vita Suprinity), and lithium disilicate glass-ceramic (LDG; IPS e.max CAD HT). Material and methods: CAD/CAM blocks of 2-mm thickness were sectioned with a slow-speed diamond-saw sectioning machine. The slabs were then embedded in autopolymerizing acrylic resin (n = 12), and resin cements were applied to the surface of the specimens. All specimens were stored in water for 24 h and subjected to 5000 thermal cycles. Bond strength was measured by means of the shear bond strength test. The data were statistically analyzed by two-way ANOVA and Tukey LSD post hoc tests. Results: The results of the two-way ANOVA test indicated that the bond strength values varied significantly depending on the CAD/CAM restorative materials, resin cements, and interaction of these variables (p < 0.05). The RNC group showed the highest bond strength for Panavia F 2.0 (p < 0.05); there were no significant differences among other CAD/CAM materials for Panavia F 2.0 (p > 0.05). The LDG group showed the highest bond strength for Multilink N, it was followed by the ZLDC group (p < 0.05); there were no significant differences between RNC and HC groups (p > 0.05). Conclusions: Choosing resin cements for restorations should be done carefully because bond strength values vary significantly depending on the resin cement and CAD/CAM restorative material.

Sari F, et al. J Adv Prosthodont. 2016 Aug;8(4):267-274. https://doi.org/10.4047/jap.2016.8.4.267