Background/Objectives: Chipping of the veneering part of the crown at the zirconia–porcelain interface remains a major complication of bilayered zirconia systems. This systematic review evaluated whether incorporating a lithium-disilicate (LD) liner or press-on or CAD-on interlayer between zirconia and veneer improves bond strength and fracture performance in vitro. Methods: Following PRISMA 2020, we searched PubMed, Scopus, and Web of Science up to 7 September 2025 for open-access English in vitro studies using LD-based interlayers at zirconia–veneer interfaces and reporting quantitative bond and/or fracture outcomes. Data included extracted materials, processing parameters, and mechanical results; due to heterogeneity, findings were synthesized descriptively and as the ratio-of-means (ROM). Results: Five in vitro studies from Korea, Thailand, and India met the criteria. LD interlayers increased microtensile bond strength from 18.83 to 44.20 MPa and from 19.6 to 47.7 MPa, and shear bond strength from 41.3 to 59.7 MPa, 11.40 ± 1.29 to 18.81 ± 1.76 MPa, and 21.5 to 60.2 MPa. Corresponding ROMs ranged from 1.46 to 2.80 (median 2.35), with thermocycled LD groups maintaining strengths >25 MPa. LD liners also raised crown fracture loads from ~2.18 to ~3.45 kN and characteristic strength from 3.42 to 5.64 kN, while chipping loads in implant crowns increased from ~0.34 to ~0.84 kN and global fracture from ~1.71 to ~1.93 kN. Conclusions: Across diverse zirconia–veneer configurations, LD interlayers consistently enhanced bond metrics and fracture/chipping resistance, supporting their use as a targeted interfacial strategy; however, clinical confirmation is still needed.

Caries control is essential for the long-term success of dental restorations, and the frequent use of mouthwashes may influence the esthetic properties of restorative materials. This study aimed to evaluate the effect of several commercially available mouthwashes on the color stability of resin-based CAD/CAM restorative materials. Three CAD/CAM materials were investigated: a hybrid ceramic (Cerasmart), a polymer-infiltrated ceramic (Vita Enamic), and a reinforced composite (Brilliant Crios). Rectangular specimens were immersed in Eludril Classic, Listerine Total Care, Listerine Advanced White, and distilled water (control). Color measurements were performed at baseline and after immersion periods up to 24 h using a digital spectrophotometer, and color differences (ΔE₀₀) were calculated. Statistical analysis revealed that both mouthwash type and immersion time had a statistically significant effect on color change (p ≤ 0.05). All tested materials exhibited ΔE₀₀ values exceeding the clinically acceptable threshold. These findings suggest that prolonged mouthwash use may compromise the esthetic longevity of resin-based CAD/CAM restorations. The null hypothesis was that prolonged use of mouthwash does not influence the color of resin-based CAD/CAM materials especially for those containing alcohol.

Background/Objectives: Oral diseases are among the most prevalent non-communicable diseases and impose a substantial public health burden across Europe. Although general total health expenditure may reflect health-system capacity, it does not specifically measure oral healthcare financing, and evidence regarding its association with population-level oral health remains limited. The objective of this study was to assess the association between total health expenditure and oral health outcomes in European countries. The primary focus was on dental caries prevalence, while a secondary exploratory analysis examined edentulism. Methods: Using publicly available international databases, an ecological, unbalanced country-level panel dataset was constructed. The main caries model included 153 country-year observations from 25 European countries during 2015–2021. An extended model incorporating practicing dentist density included 109 observations from 20 countries. Two-way fixed-effects regression models with country and year effects and country-clustered standard errors were applied. Edentulism was examined using exploratory cross-sectional OLS models for 2019. Results: In the main model, higher total health expenditure (β = −0.00305, p = 0.027) and GDP per capita (β = −0.00024, p = 0.021) were associated with lower caries prevalence. In the extended model, only GDP per capita remained statistically significant (β = −0.00028, p = 0.021), whereas total health expenditure, tertiary educational attainment, and practicing dentist density were not significantly associated with caries prevalence. No statistically significant associations were observed in the exploratory edentulism analyses. Conclusions: Total health expenditure and GDP per capita were negatively associated with caries prevalence in the main country-level model, although the expenditure association was not maintained in the restricted extended sample. These ecological findings do not establish causality and require confirmation using more complete, oral-health-specific data.

Background: Clinical evidence regarding lithium-silicate-modified zirconia veneers and partial-coverage restorations remains limited. This retrospective study compared the observed three-year outcomes of two complete adhesive restorative protocols rather than the isolated effects of ceramic materials. Materials and Methods: One hundred ceramic veneers and partial-coverage restorations placed in eleven patients were evaluated after a three-year follow-up. Fifty restorations were fabricated from lithium disilicate (IPS e.max Press; Ivoclar Vivadent AG, Schaan, Liechtenstein), and fifty were fabricated from zirconia (Aidite Biomedical Co., Ltd., Qinhuangdao, China) treated with the Biomic LiSi Connect system. No patient received both protocols. Clinical records, photographic documentation, and recall examinations were reviewed for fractures, chipping, marginal discoloration, surface wear, secondary caries, hypersensitivity, repairs, replacements, and debonding. Outcomes were analyzed descriptively because multiple restorations were clustered within patients and protocol allocation followed clinical indication. Wilson 95% confidence intervals (CIs) were reported for restoration-level proportions as descriptive measures and were not adjusted for clustering. Results: Both protocols showed 100% survival without replacement (95% CI: 92.9–100.0%). Debonding affected 6/50 zirconia restorations (12%; 95% CI: 5.6–23.8%) and 0/50 lithium disilicate restorations (0%; 95% CI: 0.0–7.1%). The six events occurred in five of seven zirconia patients and none of four lithium disilicate patients. All debonded restorations were recemented and remained functional. No fractures, chipping events, repairs, or replacements were recorded. Conclusions: No replacement or structural failure was observed during three years in this selected convenience cohort. However, the zirconia protocol had six retention-related interventions. Because the protocols differed in material, surface treatment, cement, indication, and anatomical distribution, the findings are exploratory and do not establish an isolated material effect.

Background/Objectives: Tooth discoloration can influence the esthetic outcome of restorative treatments. Recently, 3D-printed ceramic-filled hybrid materials have been introduced for dental restorations using digital workflows. The aim of this in vitro study was to evaluate the influence of 3D-printed ceramic-filled hybrid veneers on the final color of discolored teeth using spectrophotometric measurements. Methods: Twenty-five extracted human anterior teeth without caries or restorations were prepared for veneer restorations using standardized reduction protocols. Artificial discoloration was induced by applying light-cured color coatings to the buccal surfaces of the specimens. The prepared teeth were digitally scanned, and veneers with a thickness of 1 mm were designed and fabricated using a 3D printing system and a ceramic-filled hybrid material. Color measurements were performed with a spectrophotometer and recorded in the Commission Internationale de l’Éclairage L*a*b* (CIELAB) color system. Measurements were obtained at four stages: after creation of discoloration, after two weeks of immersion in physiological saline solution, after veneer placement using neutral try-in gel, and after two months of immersion following veneer placement. Color differences were calculated using three color difference formulas (ΔE*ab, ΔE94, and ΔE00). Results: The placement of the 3D-printed veneers produced substantial modifications in the optical characteristics of the discolored substrates, reflected by reduced chroma values and significant color differences between the baseline and veneer stages. After two months of immersion, only minor variations in color coordinates were observed. The calculated color differences between the veneer stage and the post-immersion stage remained low across all evaluated color difference formulas, indicating good short-term color stability of the veneered specimens. Conclusions: Within the limitations of this pilot in vitro study, 3D-printed ceramic-filled hybrid veneers demonstrated the ability to effectively modify the color of discolored substrates while maintaining relatively stable optical properties after two months of immersion. These restorations may represent a promising and cost-effective option for the esthetic management of discolored teeth.