Dental ceramics are susceptible to slow, progressive crack growth after cyclic loading. The purpose of this study was to investigate the progressive patterns of cracks in two different types of CAD/CAM ceramic materials used with three different partial posterior indirect restoration (PPIR) designs and to determine the materials’ failure risk using a fatigue test. Standard initial cracks were formed in Standard Tessellation Language (STL) files prepared for three different PPIRs. The materials chosen were monolithic lithium disilicate (LS) and polymer-infiltrated ceramic networks (PICNs). The extended finite element method (XFEM) was applied, and the fatigue performance was examined by applying a 600 N axial load. The cracks propagated the most in onlay restorations, where the highest displacement was observed. In contrast, the most successful results were observed in overlay restorations. Overlay restorations also showed better fatigue performance. LS materials exhibited more successful results than PICN materials. LS materials, which can be used in PPIRs, yield better results compared to PICN materials. While inlay restorations demonstrated relatively successful results, overlay and onlay restorations can be specified as the most and the least successful PPIR types, respectively.

Aim: The aim of this study was to investigate the effect of using aesthetic restorations and abutments in cases where implants will be applied in the anterior region on the stress distribution on implant components and surrounding biological tissues. Methodology: The data was created in the SolidWorks program, with cortical bone approximately 2 mm thick and trabecular bone approximately 15 mm thick. An implant obtained from a dental implant company, with a length of 12 mm and a diameter of 3.7 mm, was placed into the created data. The obtained data was exported as the Standard Tessellation Language (STL) file and imported into the EXOCAD program. A custom abutment and a prosthetic restoration with central incisor morphology were designed within the data, and all data were exported in STL format and re-imported into SolidWorks. Cement data with a thickness of 30 μm was created, and then all parts were assembled appropriately. The assembled data was converted to Standard for the Exchange of Product Model Data (STP) format and transferred to the ABAQUS program. In ABAQUS, zirconia was assigned to the custom abutments, dual-cure resin cement to the cement, and three different all-ceramic materials, MZ, zirconia-reinforced lithium silicate (ZLS), and lithium disilicate glass ceramics (LS), to the restoration material. A load of 150 N was applied obliquely at a 30º angle to the palatoincisal corner, and the resulting values were recorded as von Mises stress (VMS) values. Results: In each of the three restorations, the highest von Mises stress value occurred around the abutment, while the lowest stress value was observed in the trabecular bone. The stress value around the restoration was highest in monolithic zirconia. The highest stress value around the abutment was observed in lithium disilicate. Conclusion: In cortical and trabecular bone, similar values were found across all three restorations. The highest stress concentration, excluding the area around the restoration, was observed in lithium disilicate. How to cite this article: Avcı FN, Mohammadi R, Keçeci M, Demirel MG. Investigation of the effects of various restorative materials on stress distribution in a zirconia abutment in the anterior region: A finite element analysis. Int Dent Res. 2024;14(S1):106-113. https://doi.org/10.5577/indentres.569

Aim: Rehabilitation of tooth losses with fixed prosthesis applications is still a highly preferred option today. Teeth are the most important components for chewing function, proper phonation, and aesthetics. The aim of the study is to examine the relationship between tooth loss and fixed prosthetic restorations in patients of different age groups and genders. Methodology: In this study, a total of 300 patients were studied to examine the relationship between tooth deficiencies and the number of fixed restorations applied with gender and age. These patients were divided into two gender groups, male and female, and six age groups, with n = 25 in each group. Fixed prosthetic restorations in the missing teeth and mouths of the patients were recorded on dental panoramic radiographs. Statistical analysis was conducted with the one-way ANOVA test. Results: Tooth loss and the number of prosthetic applications increased statistically with age, but no statistical difference was found with gender. The Independent samples t-test analysis of variances was used in this study (p < 0.05). Conclusion: Tooth loss increases in patients with age due to many factors. This problem should be prevented by popularizing preventive dental practices. Female patients with poor dental hygiene and tooth loss associated with hormonal changes in specific age ranges have increased. How to cite this article: Keçeci M, Demirel MG. The effect of age and gender on tooth loss in different jaw areas and fixed prosthetic dental treatments. Int Dent Res 2023;13(1):7-12. https://doi.org/10.5577/idr.2023.vol13.no1.2 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Background: This was aimed to investigate the effect of surface treatment with different primers on the shear bond strength (SBS) between metallic brackets and monolithic zirconia crowns.Methods: Sixty-five monolithic zirconia molar crowns were fabricated with CAD-CAM technology. All crowns underwent thermal cycling. After aging, crowns were randomly divided into five groups (n = 13) according to cementation procedures: orthodontic bonding system; primer/composite paste: Transbond XT (TXT) (control); Group M: Monobond Plus (MP) was applied on crowns surfaces then TXT composite paste; Group MT: MP was applied on crown surface then primer/composite paste of TXT; Group Z: Z-Prime Plus (ZP) was applied on crown surface then TXT composite paste; Group ZT: ZP was applied on crown surface then primer/composite paste of TXT was used for bonding the metallic brackets. The bracket-bonded crowns were tested for SBS using a universal testing machine. Results were analyzed using analysis of variance.Results: A statistically significant difference was found between all groups regarding SBS values (p=0.001). Group MT showed the highest SBS value, the control group showed the lowest SBS value (p<0.05).Conclusion: It can be concluded that all bracket-bonded crowns were sufficient to withstand orthodontic forces. Surface treatment with primers contributes to increase the shear bond strength between metallic bracket and monolithic zirconia.

Aim: The aim of this study is to investigate the stress distribution in implant-supported three-unit monolithic zirconia restorations according to different bone levels at which implants are placed in the mandible, using three-dimensional finite element analysis. Methodology: For this study, mucosal, trabecular, and cortical bone pieces were designed using the SolidWorks program to simulate an edentulous mandibular jawbone. Two implants were positioned in areas numbered 44 and 46 with different subcrestal placements (0 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm). In each model, dental implants, abutments (TiBase), monolithic zirconia crowns, abutment screws, and bone tissues were simulated. The obtained data were exported as Standard Tesselation Language (STL) files and imported into the Exocad program for the design of prosthetic restorations and custom abutments. The STL files were then imported into the Geomagic Design X program to merge the implants, abutments, and restorations on the digital model. The final models were saved as STP files and transferred to the ABAQUS software for finite element analysis. Subsequently, an oblique load of 150 N in the buccolingual direction was applied to the occlusal table for 1000 cycles, and the mandibular jawbone was fully constrained (encastre) in all directions (both movement and rotation). Stress distribution values were recorded in von Mises (vMS) units, and fatigue performances were measured using the Seegers method. Results: As the implant bone levels increased, the vMS increased on the prosthetic restoration. Specifically, vMS increased on the abutment of implant 44 but decreased on implant 46. Fatigue performance worsened on the abutment of implant 44 but improved on the abutment, and screws of implant 46. Abutment screws proved most durable, with abutments experiencing early failures. Conclusion: According to the results of the study, it has been observed that the implant bone level affects the stresses occurring in prosthetic restoration. How to cite this article: Alioğlu Koparal NS, Tunçdemir AR, Demirel MG, Mohammadi R, Keçeci M. The effect of different implant-bone levels on stress distribution in three-unit monolithic zirconia restorations: A 3D finite element analysis. Int Dent Res. 2024;14(S1):81-89 https://doi.org/10.5577/indentres.566

Objective: This study aimed to evaluate the effect of alcohol content in mouthwashes on the color stability of monolithic zirconia.Materials and Methods: A total of 72 monolithic zirconia samples were fabricated as disks with a diameter of 10 mm and a thickness of 2 mm. The samples were randomly divided into two groups based on surface treatment methods: mechanical polishing and glazing. Following the surface treatments, each group was further divided into three subgroups based on the immersion solution: distilled water, alcoholic mouthwash, and non-alcoholic mouthwash. Color measurements were performed using a spectrophotometer at baseline and after immersion in the respective solutions.Results: Surface treatment significantly influenced color change (F = 17.491, p = 0.001). Similarly, the type of immersion solution had a statistically significant impact on color stability (F = 21.986, p = 0.001), with the solution type exhibiting the largest effect size among individual factors. The interaction between surface treatment and immersion solution also resulted in a statistically significant difference in color change (F = 24.532, p = 0.001).Conclusion: Glazed surfaces demonstrated a statistically significant reduction in color change regardless of the mouthwash content, ensuring clinically acceptable color stability. However, alcohol-containing mouthwashes were associated with surface wear, leading to greater color deterioration over time.