Background/Objectives: Modern restorative dentistry increasingly focuses on achieving optimal aesthetic integration while simplifying clinical procedures. Single-shade resin composites were introduced to reduce the complexity of conventional multi-shade layering techniques through enhanced color adjustment potential and structural color technology. However, concerns remain regarding their long-term color stability. The aim of this systematic review was to evaluate the color stability and aesthetic performance of single-shade resin composites compared with conventional multi-shade systems under different staining and aging conditions. Methods: This systematic review was conducted according to PRISMA 2020 guidelines and registered in the Open Science Framework. A systematic search was performed in PubMed, Scopus, and Cochrane Library up to 31 October 2025. Studies evaluating color stability using the CIEDE2000 (ΔE₀₀) formula after staining and aging procedures were included. Risk of bias was assessed using the RoBDEMAT tool. Results: The search identified 169 records, of which 11 in vitro studies met the inclusion criteria. Across the included studies, discoloration increased progressively over time, and chromogenic agents frequently induced ΔE₀₀ values exceeding clinical acceptability thresholds. Turmeric and red wine demonstrated the highest staining potential, whereas distilled water and artificial saliva showed minimal color variation. Single-shade composites generally exhibited greater susceptibility to discoloration than multi-shade systems, although variability among materials was observed depending on composition and experimental conditions. Conclusions: Single-shade resin composites simplify restorative procedures and provide initial aesthetic integration; however, they appear more susceptible to clinically relevant discoloration under experimental conditions. Further clinical and in vitro investigations are required to confirm these findings.

Background: This proof-of-concept clinical study evaluated the feasibility, applicability, tolerability, and preliminary response of a customised 3D-printed, thermoformed intraoral device for gingival topical treatment. Immune-mediated conditions, including oral lichen planus, mucous membrane pemphigoid, and pemphigus vulgaris often cause desquamative gingivitis. Topical corticosteroids are often ineffective in the oral environment, and frequent reapplication may increase systemic absorption. Methods: Two adults with immune-mediated gingival disease—oral lichen planus and mucous membrane pemphigoid—were unresponsive to topical corticosteroids. Following intraoral scanning, digital design, 3D printing, and thermoforming, each received a custom device with reservoirs over the lesions. They applied the corticosteroid gel and wore the device for 30 minutes, three times daily, in four cycles of five treatment days and two rest days. Results: Both cases completed the digital workflow successfully, with high compliance and no device-related mucosal irritation or pressure lesions. Mean pain scores fell from 8.5 at T0 to 4 at T1 (day 20) and 1.5 at T2 (day 40). Erythema and erosive areas decreased markedly, while symptoms nearly resolved. Conclusions: Device-mediated clobetasol was feasible, well tolerated, and effective in two topical treatment–resistant patients, but is currently limited to keratinized, dentition-supported sites (gingiva and palate). Randomized controlled trials must confirm efficacy versus conventional application.