STATEMENT OF PROBLEM Whether additively manufactured (AM) and subtractively manufactured (SM) zirconia differ in optical behavior under staining and aging remains uncertain. PURPOSE The purpose of this systematic review and meta-analysis was to evaluate differences in color stability (ΔE), translucency (TP), and translucency change (ΔTP) between AM and SM zirconia after aging. MATERIAL AND METHODS An electronic search was conducted across the PubMed, Embase, Scopus, Web of Science, the Cochrane Library, and Google Scholar databases through October 2025. Eligible studies were English-language in vitro investigations directly comparing AM and SM zirconia for ΔE, TP, or ΔTP. The data were pooled using a random-effects model and expressed as weighted mean differences (WMDs) with 95% confidence intervals. Heterogeneity was analyzed using Cochran Q and I² statistics, and publication bias was examined with the Egger test and trim-and-fill correction. Risk of bias was assessed using the RoBDEMAT tool. RESULTS From 4218 records, 5 in vitro studies were included. AM zirconia showed lower ΔE (WMD=-0.226; 95% CI: -0.349 to -0.103; P<.001; I²=97.1%), lower TP (WMD=-4.191; 95% CI: -4.958 to -3.423; P<.001; I²=98.0%), and greater ΔTP after aging (WMD=0.887; 95% CI: 0.091 to 1.683; P=.029; I²=97.0%) compared with SM zirconia. CONCLUSIONS AM zirconia demonstrated less color alteration, lower initial translucency, and higher translucency variation after aging than SM zirconia. However, these optical differences remained within clinically acceptable thresholds.
STATEMENT OF PROBLEM Cytokines present in saliva play a key role in regulating inflammatory and immune responses. Their detection may provide valuable diagnostic insights, particularly in subclinical or asymptomatic conditions. Whether wearing removable dentures provokes chronic, low-grade mucosal irritation initiating an inflammatory response is unclear. PURPOSE The purpose of this study was to compare the salivary concentrations of selected cytokines in asymptomatic denture wearers and individuals with natural dentition and to compare the concentrations of proinflammatory cytokines (TNF-α, IL-1β, IL-2, IL-6, IL-17) and antiinflammatory cytokines (IL-1Ra, IL-4, IL-10) in the unstimulated saliva of asymptomatic denture wearers with those of people with healthy natural teeth to assess whether the measurement of these parameters might indicate early, clinically invisible inflammatory processes in the oral cavity. MATERIAL AND METHODS Fifty-five patients (47 women, 8 men), aged 31 to 79 (58.8 ±12.8), were enrolled in the study. The denture group included 34 patients using removable dentures, while the control group consisted of 21 individuals with healthy natural teeth. None of the participants showed any clinical signs of oral inflammation. Unstimulated whole saliva was collected between 10 AM and 11 AM under standardized conditions. Concentrations of proinflammatory (TNF-α, IL-2, IL-17) and antiinflammatory (IL-4, IL-10) cytokines were measured using Bio-Plex technology (xMAP system; Bio-Rad). Statistical analyses were performed with Statistica 13.3 using the Shapiro-Wilk test for normality assessment, and the Mann-Whitney U test or chi-squared test for group comparisons (α=.05). RESULTS Compared with the control group, significantly higher salivary concentrations of TNF-α (P=.024), IL-2 (P=.020), IL-17 (P=.016), IL-4 (P=.007), and IL-10 (P=.009) were observed in the denture-wearing group. A strong positive correlation was found between TNF-α and IL-17 levels (r=.686; P<.05), as well as between IL-4 and IL-10, maintaining immune balance in the oral mucosa. CONCLUSIONS The elevated levels of both proinflammatory and antiinflammatory cytokines in asymptomatic denture wearers may reflect subclinical mucosal irritation and an ongoing local immune response. These findings indicated that salivary cytokine analysis may serve as a valuable, noninvasive diagnostic tool for the early detection of inflammation and the identification of patients at risk for denture-related stomatitis (DRS), even before clinical symptoms appear. Further studies on larger populations are warranted to confirm the prognostic utility of salivary biomarkers in prosthetic dentistry.
