To compare laboratory production time, clinical adjustment time, and patient-reported comfort of three occlusal splint fabrication techniques (heat-cured acrylic, vacuum-adapted acrylic, and CAD-CAM 3D-printed splints) in a pilot feasibility study. Three participants each received three splints, one fabricated with each technique. Laboratory production time, chairside adjustment time, and comfort (VAS) were recorded. Vacuum-adapted splints required the shortest laboratory production time (mean = 92 min, SD = 25.35). Heat-cured splints required longer processing (mean = 114 min, SD = 6.08). The CAD-CAM splints showed the longest total workflow duration (mean = 133 min, SD = 6.08), although they required less manual technician work. Intraoral adjustment times were similar between heat-cured and vacuum-adapted splints (means = 28 min and 26.66 min, respectively). None of the CAD-CAM splints seated fully at delivery, preventing proper adjustment. Vacuum-adapted splints received the highest comfort scores. Within the limitations of this pilot study with three participants, vacuum-adapted and heat-cured splints showed clinically acceptable performance and comparable adjustment times. CAD-CAM splints reduced manual workload but suffered from significant seating and fit issues, indicating the need for workflow refinement before clinical implementation. Even as splint fabrication is moving towards a more digital workflow, the old methods, especially vacuum-adapted splints, continue to deliver timely and comfortable results to patients. Further studies with more participants need to be done so that there can be a clear digital splint fabrication workflow.

Background/Objectives: Provisional restorations are widely used in fixed prosthodontics, and polymethyl methacrylate (PMMA) remains one of the most commonly used materials. Discoloration during intraoral service may compromise their esthetic acceptability. Graphene-reinforced PMMA has been introduced to improve material performance, although its color stability under simulated oral conditions remains insufficiently characterized. This study aimed to compare the color changes in conventional PMMA and graphene-reinforced PMMA after exposure to salivary pH variations and coffee, combined with simulated masticatory movements. Methods: Forty PMMA and forty graphene-reinforced PMMA (G-CAM) disk-shaped specimens (8 mm × 2 mm) were allocated to eight original experimental groups according to material and condition (pH 7, coffee, pH change, or pH change plus coffee), under simulated chewing movements. Color was recorded before and after the procedures using an imaging system, and values were converted into CIELAB coordinates. Statistical analysis included Wilcoxon, Mann–Whitney U, Kruskal–Wallis, and Bonferroni-adjusted pairwise comparisons, with a significance level set at p < 0.05. Results: Both materials exhibited measurable color changes after the experimental procedures. PMMA showed higher median ΔE values than graphene-reinforced PMMA in the coffee and pH change plus coffee conditions, where the differences between materials were statistically significant. The highest color changes were observed in PMMA exposed to coffee and to the combined pH change plus coffee protocol, exceeding the clinical acceptability threshold. Conclusions: Graphene-reinforced PMMA (G-CAM) showed greater color stability than conventional PMMA, although neither material can be considered completely color stable. The greatest color variation was observed in the groups exposed to pH change followed by coffee immersion, as reflected by ΔE values.

Visual shade selection remains widely used in restorative and prosthetic dentistry and is influenced by interobserver variability, illumination conditions, and individual visual factors. However, the relationship between colour perception screening findings and shade-matching performance in undergraduate dental students remains insufficiently explored. To assess colour perception screening findings and shade-matching performance among undergraduate dental students using the Ishihara test and practical shade-selection tasks. An exploratory cross-sectional study was conducted including 80 fourth- and fifth-year dental students enroled in the prosthodontics course at the University of Barcelona during the 2017-2018 academic year. Colour perception was screened using the Ishihara 24-plate test. Shade-matching performance was evaluated through two practical tasks: pairing corresponding tabs from two Chromascop shade guides and selecting the reference shade of a ceramic crown. Incorrect responses, shade-selection discrepancies, and completion time were recorded. Statistical analysis included descriptive statistics and bivariate tests selected according to the type of variable and expected cell frequencies. Eighty students participated in the study (33.75% male, 66.25% female). Ishihara screening findings compatible with colour vision deficiency were observed in 2.5% of participants, while isolated incorrect plate responses were observed in a larger proportion of students. Shade-matching discrepancies were frequent in both practical tasks. Self-reported ophthalmological conditions were associated with a higher number of shade-selection discrepancies (p < 0.05). Longer completion times tended to be associated with more discrepancies, although this association was not statistically significant. No significant differences were observed according to sex. Within the limitations of this exploratory study, shade-matching discrepancies were common among undergraduate dental students and were not limited to participants with Ishihara screening findings compatible with colour vision deficiency. These findings support the relevance of structured training in colour science and shade selection during prosthodontic education. Further studies using standardized perceptual and instrumental reference methods are needed.

Implant-supported hybrid metal–resin prostheses are widely used to rehabilitate edentulous patients. However, fractures of the veneering resin and screw complications remain common mechanical failures. Advances in CAD-CAM design and laser sintering technology may improve the structural integrity of these restorations. To conduct a preliminary in-vitro evaluation of the fracture resistance of veneering resin in three CAD-CAM–designed bar configurations fabricated by laser sintering, describing their mechanical behavior and failure patterns under compressive stress. Three bar designs (inverted T, L-shaped, and Ackerman circular) were digitally created and manufactured in cobalt–chromium using laser sintering. Each bar was veneered with autopolymerizing acrylic resin and subjected to compressive loading up to 1000 N at a 30° angle, in accordance with ISO 14801. Simultaneously, acoustic emission analysis was performed to detect microcracks and structural failures. No fractures of the veneering resin were observed. Mechanical failures occurred as deformation or fracture of prosthetic screws, beginning at 600 N. Acoustic emission detected early microcracks between 160 N and 400 N, and main fracture peaks between 627 N and 871 N. Among the three samples, the inverted T-shaped bar sustained the highest load before failure in this pilot test. In this pilot in-vitro study, the veneering resin showed high resistance under simulated masticatory loading. The combination of CAD-CAM design, laser-sintered fabrication, and retentive elements may enhance mechanical performance. Further studies with larger sample sizes and cyclic loading are warranted to validate these preliminary findings.

The increasing aesthetic demand in dentistry and the limitations of visual colour assessment have encouraged the development of objective methods for evaluating dental and peri-implant tissues. Although colourimeters were originally designed for tooth shade matching, their application has recently expanded to peri-implant soft-tissue analysis, providing quantitative and reproducible measurements capable of detecting early inflammatory changes. This study aimed to determine whether colour analysis using a colourimeter is a valid diagnostic tool for the preliminary detection of peri-implant diseases by comparing colourimetric data with conventional clinical findings. A cross-sectional, descriptive, and experimental study was conducted on 63 dental implants. Peri-implant soft-tissue colour was recorded using a colourimeter based on CIELab parameters (L∗, a∗, b∗). Each implant also underwent clinical evaluation including visual inspection, periodontal probing, and periapical radiography. Two measurement points were analysed: Point A, located 2 mm apical to the gingival margin, and Point B, positioned beyond the probing depth for each implant. Colourimetric values from both points were compared with the clinical diagnosis obtained for every implant. At Point B, peri-implant tissues showed lower luminosity (L∗), higher redness (a∗), and reduced b∗ values compared with Point A. Clinically, 48 implants presented peri-implantitis, 9 mucositis, and 6 were considered healthy. Diseased implants demonstrated darker and more reddish peri-implant tissues, revealing a clear correlation between colour alterations and inflammatory status.