This study aimed to predict the skeletal growth maturation using convolutional neural network-based deep learning methods using cervical vertebral maturation and the lower 2nd molar calcification level so that skeletal maturation can be detected from orthopantomography using multiclass classification. About 1200 cephalometric radiographs and 1200 OPGs were selected from patients seeking treatment in dental centers. The level of skeletal maturation was detected by CNN using the multiclass classification method, and each image was identified as a cervical vertebral maturation index (CVMI); meanwhile, the chronological age was estimated from the level of the 2nd molar calcification. The model’s final result demonstrates a high degree of accuracy with which each stage and gender can be predicted. Cervical vertebral maturation reported high accuracy in males (98%), while females showed high accuracy of 2nd molar calcification. CNN multiclass classification is an accurate method to detect the level of maturation, whether from cervical maturation or the calcification of the lower 2nd molar, and the calcification level of the lower 2nd molar is a reliable method to trust in the growth level, so the traditional OPG is enough for this purpose.

The effects of incorporating a pioneer chitosan–TiO₂ nanocomposite on the mechanical and physical properties of room-temperature vulcanization (RTV) maxillofacial A-2186 silicone under accelerated aging protocols were rigorously examined. This investigation utilized 450 samples distributed across five distinct silicone classifications and assessed their attributes, such as tensile strength, elongation, tear strength, hardness, and surface roughness, before and after various accelerated aging processes. Statistical methodologies, including a one-way ANOVA, Tukey’s HSD, and Dunnett’s T3, were employed based on the homogeneity of variance, and several key results were obtained. Silicones infused with 1 wt.% chitosan–TiO₂ showed enhanced tensile strength across various aging procedures. Moreover, the 1 wt.% TiO₂/Chitosan noncombination (TC) and 2 wt.% TiO₂ compositions exhibited pronounced improvements in the elongation percentage. A consistent rise was evident across all silicone categories regarding tear strength, with the 1 wt.% chitosan–TiO₂ variant being prominent under certain conditions. Variations in hardness were observed, with the 1 wt.% TC and 3 wt.% chitosan samples showing distinctive responses to certain conditions. Although most samples displayed a decreased surface roughness upon aging, the 1 wt.% chitosan–TiO₂ variant frequently countered this trend. This investigation provides insights into the potential of the chitosan–TiO₂ nanocomposite to influence silicone properties under aging conditions.

This study explores the impact of the incorporation of a chitosan–TiO₂ nanocomposite on the color stability of pigmented room-temperature vulcanization maxillofacial silicone under various accelerated aging conditions. Five hundred disk-shaped specimens were formed with type A-2186 silicone elastomer, and they were distributed into groups based on pigment types and nanoparticle treatments. The color difference (ΔE) was assessed using a colorimeter in the CIELAB color system before and after exposure to aging conditions, including UV-accelerated aging and outdoor weathering. ANOVA, Dennett’s T3, and Tukey HSD tests revealed significant color alterations across all silicone types, with the most pronounced being in the red-colored 3% chitosan specimens and the least pronounced being in the 2% TiO₂ specimens that underwent UV-accelerated aging. Outdoor weathering consistently increased the ΔE values across all categories. This study suggests that while nanoparticles may offer some resistance against accelerated aging, they fall short in adequately defending against UV radiation during outdoor weathering.

The present study sought to determine the effect of incorporating a Chitosan-TiO2 nano-composite on the color stability of pigmented Room Temperature Vulcanization (RTV) maxillofacial silicone subjected to a variety of accelerated aging conditions. The experimental setup consisted of one hundred groups of five disk-shaped specimens (22mm diameter, 2mm thick) each, created using RTV silicon elastomer type A-2186, with the total sample distributed into four groups based on the pigments combined with the silicon—specifically, brilliant red, blue, and yellow dry intrinsic pigments (at 0.2% concentration by weight) and a fourth group that remained non-pigmented. Each of these primary groups was further subdivided into five categories corresponding to the silicon variants treated with different nanoparticles—2% TiO2, 3% Chitosan, a hybrid nano-combination of 1% TiO2/Chitosan, 1% synthesized Chitosan-TiO2 Nanocomposite, and a control group devoid of nanoparticle additions. The synthesized Chitosan-TiO2 Nanocomposite was effectively prepared using the core-shell method. The color stability of each silicon category, irrespective of whether pigmented or non-pigmented was evaluated by calculating the color difference (ΔE) pre- and post-subjection to five distinct accelerated aging conditions: 30 hours in an antibacterial cleaning solution, six months in sebum, six months in sweat, UV-accelerated aging for 720 hours, and outdoor weathering for six months. Color measurements were taken using a Colorimeter within the CIELAB color system. Statistical analyses, including one-way ANOVA at a significance level of p < 0.05, were employed to discern significant differences among the various accelerated aging conditions across the five silicon categories. Further comparisons were made using Dennett's T3 multiple comparison test, Tukey HSD multiple comparisons, and a t-test, with SPSS for Windows version 27.0 as the software platform. Results indicated that all silicon types, whether pigmented or not, exhibited varying degrees of color change under different aging conditions. Red-colored samples, across all silicon categories, demonstrated significant color alterations after 720 hours of UV-accelerated aging, with the most pronounced change in the 3% Chitosan samples and the least in the 2% TiO2 samples. Six months of outdoor weathering led to a marked increase in ΔE values across all categories. The blue-pigmented silicon samples treated with 2% TiO2 showed the highest color modification, while the yellow-pigmented silicon and non-pigmented silicon also underwent significant color shifts, particularly in the control and Chitosan-TiO2 categories, respectively. The study underscores the pervasive influence of outdoor weathering on color stability across all silicon categories. It also demonstrates that while nanoparticle incorporation offers some resilience against accelerated aging, it fails to provide adequate protection against the specific effects of UV radiation encountered during outdoor weathering.

Objective: Many researchers have attempted to assess 3D printing as a manufacturing method to be used as an alternative for the conventional means. The current study aimed to determine the feasibility of 3D printed complete dentures in terms of retention. Methods: An edentulous maxillary model with an overlaying layer of mucosa was fabricated by 3D printing, using two different resins for the mucosa and model, which were then glued together to establish the final model. Afterwards, 8 single step putty and wash impressions were recorded with addition silicone. Each impression was scanned with a laboratory scanner. From each impression a stone cast was fabricated on which a conventional baseplate was constructed by heat polymerized PMMA with the pack and press technique. Meanwhile, from the 8 STL files of the scanned impressions, 8 baseplates were designed and printed with the denture base resin. Next, each of the 16 baseplates were connected to a loop at their center. Finally, the retentive value of all baseplates was measured by means of the universal testing machine. A statistical analysis was performed to evaluate the significance of retentive difference between the two groups. Results: The statistical analysis revealed that the printed dentures were significantly more retentive than the conventional, with a pvalue of less than 0.029 and mean values of 15.0462 N and 12.05 N respectively. Conclusions: This study concluded that 3D printed complete dentures were significantly more retentive than the conventionally fabricated dentures

Objective: The purpose of this study was to compare the flexural strength, flexural modulus, hardness, and surface roughness of one brand each of 3D-printed and heat-cured acrylic resin materials after they were immersed in various disinfection solutions. Methods: The study included 160 specimens, consisting of 80 heat-cured and 80 3D-printed specimens. Forty specimens of each resin material type were prepared for flexural testing, while an additional forty specimens were designated for hardness and surface roughness assessments. Each collection of 40 specimens was subsequently randomized into four subgroups (n = 10) for immersion in either distilled water (control), 1% sodium hypochlorite, Superdent, or Kin Oro denture cleansers. Flexural test, hardness, and surface roughness assessments were performed. Data analysis was conducted using SPSS, with a level of significance set at p < 0.05. Results: Flexural strength and surface roughness did not differ significantly between the two resin types. Flexural modulus was significantly higher in the heat-cured resin among all the disinfectants (p = 0.000). The heat-cured resin had significantly higher microhardness than the 3D-printed resin among the disinfectants except for the Kin Oro group, and both resins showed a significant reduction in hardness after immersion in disinfectants compared to distilled water (p < 0.05). Conclusions: The heat-cured resin demonstrated higher flexural modulus and surface hardness compared to the 3D-printed resin. Flexural strength and surface roughness were comparable between the two materials. Both resins had their highest mechanical properties in distilled water.