Objective: The aim of this study is to evaluate the change in the mechanical properties of silicone elastomer used in the production of maxillofacial prostheses with the addition of 3 different nanoparticles (TiO2-SiO2-ZnO). Material and Method: TiO2-SiO2-ZnO nanoparticles were added to the A part of the M511 Platinum (Technovent Ltd., England) silicone elastomer at a rate of 2% by weight. Test specimens were produced in sizes by ASTM D412 standards for tensile strength and percent elongation, ASTM D624 for tear strength, and ASTM D2240-68 for hardness testing. For each mechanical test, 4 groups were formed together with the control group and 3 other groups to which nanoparticles were added, and a total of 132 samples were produced, 11 samples for each group (n=11), (N=132). The data of tensile strength, elongation percentage, and tear strength tests were analyzed by Shapiro Wilk's and/or Kolmogorov Smirnov/Mann Whitney U, Kruskal Wallis-H tests; for the hardness test, the values ​​in each group showed a normal distribution within themselves, hardness test was analyzed with Oneway ANOVA/Tukey HSD tests. Results: The addition of TiO2 and SiO2 to the silicone elastomer significantly increased the tensile strength compared to the other groups (p

This in vitro study evaluated the fracture resistance of CAD/CAM-fabricated lithium disilicate and 3D-printed resin crowns with varying occlusal thicknesses (0.5, 1.0, and 1.5 mm) following thermomechanical aging. Sixty extracted human molars were assigned to six experimental groups (n = 10), categorized by crown material and occlusal thickness. The crowns were fabricated using CAD/CAM technology in accordance with the manufacturer’s protocol. All specimens underwent thermomechanical aging, which consisted of thermocycling between 5 and 50 °C (5500 cycles) combined with mechanical loading of 50 N at 1.6 Hz for 75,000 cycles. The fracture loads were measured using a universal testing machine, and the failure modes were assessed using scanning electron microscopy. Statistical evaluation was performed using two-way analysis of variance with Tukey’s post hoc test (α = 0.05). Both the material type and occlusal thickness had a statistically significant effect on fracture resistance (p < 0.001). Lithium disilicate crowns exhibited higher fracture loads than 3D-printed resin crowns independent of occlusal thickness. Although the fracture resistance of 3D-printed resin crowns was lower, specimens with occlusal thicknesses ≥1.0 mm exhibited fracture loads exceeding average physiological masticatory forces, suggesting that 3D-printed resin crowns may represent a clinically acceptable option for conservative posterior restorations. In contrast, crowns with an occlusal thickness of 0.5 mm demonstrated fracture resistance values below the reported functional masticatory loads. Additionally, the proportion of repairable fractures increased with increasing occlusal thickness for both materials. Overall, the findings suggest that an occlusal thickness of at least 1.0 mm may represent a reliable threshold for posterior restorations, whereas a thickness of 0.5 mm may be insufficient to withstand functional occlusal loads in molar regions.

In recent years, the rapid advancement of digital technology has led to a significant increase in the use of 3D printers. 3D printing technologies, which are widely used in fields such as aviation, the defense industry, art, and design, have also gained importance in dentistry. By utilizing various materials and methods, these technologies have enhanced both patient and physician comfort, while reducing working time. The numerous benefits of innovations brought by digital technologies have made them increasingly popular. Today, 3D printing is used in various dental applications, including the production of guides for maxillofacial surgery, the creation of models for orthodontics, gingival surgery, removable and fixed crown bridge prostheses in prosthetic dental treatments, as well as the production of dental implants. It is also used as a space maintainer in pediatric dentistry. The purpose of this review is to provide a general overview of the use of light-cured resins in the 3D production process. Additionally, this review aims to offer insights into additive manufacturing technologies, the materials used in these technologies, and their respective advantages and disadvantages.

Overlay restorations offer a conservative solution for teeth with substantial loss of tooth structure, but their success depends largely on the preparation design, material type, and fabrication technique. This study aimed to assess the effects of two different preparation designs and fabrication techniques on the fracture resistance and marginal adaptation of overlays fabricated from zirconia-reinforced lithium silicate (ZLS) and 3D-printed resin. Forty extracted human molars were randomly divided into two preparation design groups: occlusal reduction (O) and occlusal reduction with a round shoulder (OS). Each group was subdivided based on the material type: ZLS or 3D-printed resin (n = 10 per subgroup). Restorations were designed using CAD and manufactured using milling (ZLS) or additive manufacturing (3D-Printed). After cementation and thermomechanical aging (5500 cycles, 5–50 °C), marginal gaps were measured at 20 predefined points using scanning electron microscopy (SEM). The fracture resistance was tested using a universal testing machine. Data were analyzed using two-way ANOVA and post hoc tests (α = 0.05). The preparation design had a significant effect on both fracture resistance and marginal adaptation (p < 0.05). Group O showed significantly smaller marginal gaps than Group OS for both materials. The ZLS overlays exhibited a significantly higher fracture resistance than the 3D-printed resin overlays. All groups demonstrated marginal gaps within the clinically acceptable range (<120 μm). The fracture resistance and marginal adaptation of overlay restorations are significantly influenced by the preparation design and material type. A simpler occlusal reduction design results in better marginal adaptation, whereas round shoulder preparations provide a higher fracture resistance. Although the 3D-printed resin showed lower fracture resistance, its marginal adaptation was comparable to that of milled restorations, suggesting its potential as a conservative and cost-effective polymer composite alternative for digitally fabricated overlay restorations.

Articulators are mechanical or digital devices that simulate mandibular movements and reproduce maxillomandibular relationships in prosthodontic procedures. Throughout the history of prosthodontics, articulators have evolved from simple hinge devices to sophisticated, fully adjustable mechanical and virtual systems. This review aims to provide a comprehensive overview of articulator types, classifications, and their clinical applications, emphasizing the transition from conventional to digital technologies. The advantages and limitations of mechanical, semi-adjustable, and fully adjustable articulators are discussed alongside the emerging role of digital facebows, pantographs, and virtual articulators in contemporary dental practice. The integration of CAD/CAM systems and motion-tracking technologies has led to enhanced precision, efficiency, and communication between clinicians and technicians. Although virtual articulators present significant advantages in terms of accuracy and digital workflow, they also require advanced software, sensor systems, and technical expertise. Understanding the strengths and limitations of each system enables clinicians to select the most appropriate articulator for specific clinical situations and to optimize functional, aesthetic, and occlusal outcomes in prosthodontic rehabilitation.