Permanent crown materials produced with new generation additive manufacturing and traditional subtractive manufacturing materials have not been compared in terms of wear resistance. This study aims to compare the volumetric loss related to wear and resulting surface roughness after aging in a chewing simulator between resin nano ceramics produced with milling technique and permanent crown materials produced with three dimensional (3D) printing. Three different hybrid composite-ceramic (HCC) (The three materials are GC: Cerasmart, VE: Vita Enamic, and GV: Grandio Voco.) and one 3D printed definitive crown resin (FormLabs Permanent Crown Resin) were investigated before aging (n:8), the surface roughness of all samples was measured with a profilometer, and 1 randomly selected sample from each subgroup was imaged with scanning electron microscope (SEM). 3D scans of each sample were obtained with a desktop scanner. Thermomechanical aging was performed using a chewing simulator. Four hundred thousand cycles were completed under a vertical occlusal force of 49 ± 0.7 N with a thermal cycle of 1.7 Hz 5-55° and with a dwell time of 120 s, mimicking 2 years of aging. The imaging procedures were repeated, and the change in surface roughness was evaluated. 3D images were also overlapped, and the volumetric loss was calculated with the relevant inspector software. The data obtained were analyzed by two-way ANOVA (p < 0.05). The results showed significant statistical differences for both parameters (p > 0.05). The highest volumetric loss was found in the GV group while the lowest volumetric loss was in the VE group. The highest surface roughness values were observed in the GV group, while the lowest values belonged to the VE one. Of the restorative materials evaluated, the VE group is suitable for long-term restorations, whereas the GV one is suitable for medium-term restorations. It is promising in terms of 3D printing technologies that the 3D material gives comparable results with the GV group. Additive manufacturing techniques are a successful method that accelerates the manufacturing process. Permanent crown resins are promising alternatives to conventional production.

Objective: This study investigated how the number of images collected for digital measurements in dentistry affects accuracy compared with traditional methods. Methods: A Frasaco maxillary model was scanned using a SHINING 3D AutoScan-DS-MIX dental 3D scanner to create an STL file. The maxilla was molded 10 times using polyvinyl siloxane (Zhermack Elite HD+) to produce plaster models, which were scanned with the same reference scanner to generate 10 STL files. The Frasaco model was scanned 10 times, capturing images in intervals of 800–1000, 1000–1200, and 1200–1500 using a 3Shape TRIOS 3 intraoral scanner, creating additional STL files. These were analyzed with reverse engineering software. Results: The most accurate measurements were obtained using 1200–1500 images. Conventional impression techniques performed significantly worse. There was a significant difference between the groups Digital 1200–1500 and Plaster (p < 0.001) and between Digital 800–1000 and Plaster (p = 0.007). No significant difference was found when the digital groups were compared among themselves. There was also no significant difference between the Plaster and Digital 1000–1200 groups. To compare precision values that were normally distributed across three or more methods, a one-way ANOVA was used. Trueness values that were not normally distributed with three or more methods were compared employing the Kruskal–Wallis test. Conclusions: Different image counts affect digital measurement accuracy. The most accurate measurements were obtained when collecting 1200–1500 images. Conventional impression techniques were shown to perform significantly worse than digital impression.

Occlusion plays a crucial role in maintaining masticatory function and temporomandibular joint (TMJ). Single implant supported restorations are widely used for posterior tooth replacement, but they require careful occlusal adjustment due to the absence of periodontal ligament. Digital occlusal analysis methods, such as digital impressions and Occlusense, provide quantitative assessments of occlusal contacts and force distribution. However, their accuracy and clinical relevance remain uncertain. In this prospective clinical study, occlusal force distribution was evaluated before and after placement of single implant supported restoration using the Medit i700 intraoral scanner and OccluSense system. Measurements were performed before and after prosthesis under standardised conditions. Occlusal contact areas and force distributions were analysed using CloudCompare and ImageJ software. Statistical analysis was performed using Kruskal–Wallis test and Kendall's Tau-B correlation analysis. A total of 20 patients were included in the study. Post-restoration measurements revealed significant changes in occlusal force distribution in different segments of the dental arch (p < 0.001). Strong correlations were observed between Medit and OccluSense measurements (p < 0.001). Single-unit implant restorations significantly alter the occlusal force distribution, affecting not only the restored tooth but also the adjacent and opposing teeth. Both Medit i700 and OccluSense provided valuable information, with OccluSense providing a more detailed representation of occlusal force density. These findings suggest that digital occlusal analysis methods can help optimise occlusal adjustments for implant restorations. The current study was registered in ClinicalTrials.gov (ID: NCT06862973) First posted: 07/03/2025. Retrospectively registered.

Background and Objectives: This study uses finite element analysis to evaluate the impact of abutment angulation, types, and framework materials on the stress distribution and fatigue performance of dental implant systems. Materials and Methods: Three-dimensional models of maxillary three-unit fixed implant-supported prostheses were analyzed. Abutments with different angles and types were used. Two different framework materials were used. Conducted on implants, a force of 150 N was applied obliquely, directed from the palatal to the buccal aspect, at a specific angle of 30 degrees. The distribution of stress and fatigue performance were then assessed, considering the types of restoration frameworks used and the angles of the abutments in three distinct locations. The simulation aspect of the research was carried out utilizing Abaqus Software (ABAQUS 2020, Dassault Systems Simulation Corp., Johnston, RT, USA). Results: In all models, fatigue strengths in the premolar region were higher than in the molar region. Maximum stress levels were seen in models with angled implants. In almost all models with the zirconia framework, fatigue performance was slightly lower. Conclusions: According to the findings of this study, it was concluded that the use of metal-framework multi-unit restorations with minimum angulation has significant positive effects on the biomechanics and long-term success of implant treatments.

This study aims to investigate the mechanical and optical properties of two different multilayer monolithic zirconia materials after the high-speed and repeated sintering process recommended by the manufacturers. In this study, specimens with a diameter of 12 mm and a thickness of 1 mm were fabricated using KATANA Zirconia YML (Kuraray Noritake) and IPS e.max ZirCAD Prime (Ivoclar Vivadent) multilayer zirconia. These specimens were processed with two different protocols to be used in the sintering process: high-speed and conventional sintering. Both protocols were repeated three times, after which the changes in the mechanical, microstructural and optical properties of the specimens were compared and analyzed. According to the biaxial flexural strength result, KATANA Zirconia YML (840.84 MPa) showed higher biaxial flexural strength compared to IPS e.max ZirCAD Prime (627.64 MPa) after repeated high-speed sintering. When the optical properties were analyzed, the translucency parameters of the IPS e.max ZirCAD Prime block were reliable in certain protocols. A comparison of mechanical and optical properties after repeated and high-speed sintering reveals that both materials offer advantages for different application requirements. The high biaxial flexural strength of KATANA Zirconia YML is more suitable for applications requiring strength. The homogeneous translucency of IPS e.max ZirCAD Prime is esthetically and optically safer for high-speed and repeated sintering processes.

The aim of this in vitro study is to compare the shear bond strengths of denture base resins obtained by different methods with different artificial teeth and to investigate their resistance to bonding by gastric acid in patients with gastroesophageal reflux disease. Samples were prepared using two different manufacturing methods for denture base resins (heat-polymerization and CAD/CAM) and three different types of artificial teeth (acrylic, Microfiller Reinforced Polymer Matrix Composite and CAD/CAM milled). CAD/CAM-milled denture base was combined with three different artificial teeth, while heat-polymerized base was combined with acrylic teeth. Each base-tooth combination was randomly divided into 2 subgroups (n = 14). One subgroup was immersed in artificial gastric acid and the other in artificial saliva solution. Shear bond strength testing was performed using a universal testing machine. The results obtained were analysed using two-way ANOVA and multiple comparisons were examined using Tukey's test. A significance level of p < 0.050 was used. The heat-polymerized acrylic base and acrylic teeth groups showed the highest shear bond strength (p < 0.001). There is no significant difference between the shear bond strengths of artificial gastric acid and artificial saliva groups (p = 0.152). CAD/CAM milled denture base resin bonded to different types of prefabricated teeth show similar shear bond strength. The bond strength of acrylic teeth bonded to a heat-polymerized acrylic base is higher. Gastric acid does not affect the shear bond strength.