Background/Objectives: Oral squamous cell carcinoma (OSCC) accounts for over 90% of oral malignancies and remains associated with substantial global morbidity and mortality. Although tobacco and alcohol are established risk factors, they do not fully explain OSCC incidence, highlighting the need to explore additional contributors such as chronic inflammatory conditions. Periodontal disease, characterized by persistent inflammation and microbial dysbiosis, has emerged as a plausible factor in oral carcinogenesis and tumor progression. To systematically evaluate the association between periodontal disease and the risk of developing OSCC, and to assess the prognostic impact of periodontal disease–related factors, particularly intratumoral Porphyromonas gingivalis, on survival outcomes in patients with OSCC. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines and prospectively registered in PROSPERO (CRD420261296479). Comprehensive searches were performed in PubMed, EMBASE, Web of Science, Scopus, the Cochrane Library, ClinicalTrials.gov, and World Health Organization regional databases. Case–control studies evaluating OSCC risk and cohort studies assessing survival outcomes were included. Random-effects meta-analyses using inverse-variance models were applied. Heterogeneity was assessed using the I² statistic, and robustness was evaluated through Hartung–Knapp adjustment, leave-one-out sensitivity analyses, and Trial Sequential Analysis. Results: Five case–control studies were included in the etiological analysis. Periodontal disease was significantly associated with an increased risk of OSCC (pooled OR = 3.17; 95% CI: 1.94–5.21), with moderate heterogeneity (I² = 58.7%). Two cohort studies were included in the prognostic analysis. High intratumoral expression of P. gingivalis was significantly associated with poorer overall survival (pooled HR = 2.15; 95% CI: 1.33–3.47), with no detected heterogeneity (I² = 0%). Conclusions: Periodontal disease is strongly associated with an increased risk of OSCC, and intratumoral P. gingivalis appears to be an adverse prognostic marker. These findings underscore the relevance of periodontal inflammation and microbial factors across the OSCC continuum, from carcinogenesis to clinical outcomes, and support their consideration as potential targets for risk stratification and prevention strategies.

Background: Osteoradionecrosis (ORN) is a severe late complication of radiotherapy for head and neck cancer, associated with impaired bone healing, infection, pain, and exposed bone. Periodontal disease may contribute to ORN by maintaining inflammatory and infectious foci within irradiated tissues with reduced vascularity and repair capacity. Objective: To evaluate whether periodontal disease or poor periodontal status is associated with increased ORN risk in patients with head and neck cancer undergoing radiotherapy. Methods: This systematic review and meta-analysis followed PRISMA 2020 recommendations and was structured according to the PECO framework. Searches were conducted in PubMed/MEDLINE, Embase, Scopus, Web of Science, Cochrane Library, ClinicalTrials.gov, WHO databases, and gray literature. Observational studies involving head and neck cancer patients treated with radiotherapy and reporting periodontal status in relation to ORN were included. Risk of bias was assessed using a domain-based approach. Random-effects models estimated pooled relative effect estimates and ORN prevalence. Results: Six studies were included in the primary association meta-analysis. Periodontal disease was significantly associated with increased ORN risk, with a pooled relative effect estimate of 4.83 (95% CI: 1.96–11.93; p = 0.0006; I² = 50.4%). Seven studies including 1785 patients and 118 ORN events were included in the prevalence meta-analysis, showing a pooled ORN prevalence of 9% (95% CI: 6–13%; I² = 78.0%). Conclusions: The findings suggest that periodontal disease or poor periodontal status may be associated with an increased likelihood of ORN in patients with head and neck cancer undergoing radiotherapy. Given the observational nature of the evidence and the moderate between-study heterogeneity, this association should be interpreted cautiously. Comprehensive periodontal assessment and long-term oral surveillance may be considered as components of multidisciplinary care before and after radiotherapy.

Background: Periodontitis is a chronic inflammatory disease characterized by progressive destruction of the tooth-supporting tissues and may substantially impair oral health-related quality of life (OHRQoL). Although the clinical consequences of periodontitis are well documented, the extent to which disease severity is associated with patient-reported outcomes remains insufficiently understood. This study aimed to evaluate the association between periodontitis severity and OHRQoL and to examine sociodemographic, behavioral, and systemic factors associated with poorer OHRQoL. Methods: A cross-sectional analytical study was conducted among 136 adult patients diagnosed with stage II or stage IV periodontitis at the Periodontology Clinic of Universidad Tecnológica de México (UNITEC). OHRQoL was assessed using the Oral Health Impact Profile for Periodontal Disease (OHIP-14-PD). Sociodemographic characteristics, smoking status, and diabetes mellitus were recorded using a structured questionnaire. Periodontal status was determined through standardized clinical and radiographic examinations. The internal consistency of the OHIP-14-PD was evaluated using Cronbach’s alpha coefficient. Bivariate analyses were performed using non-parametric tests. An exploratory, partially adjusted multivariable linear regression model including sex, marital status, diabetes mellitus, and periodontitis stage was also performed. Results: Stage IV periodontitis was more prevalent than stage II periodontitis (55% vs. 45%). The mean OHIP-14-PD score was 24.9 ± 13.7, and the instrument demonstrated excellent internal consistency (Cronbach’s α = 0.89). Patients with stage IV periodontitis had significantly higher OHIP-14-PD scores than those with stage II disease (30.1 ± 12.4 vs. 18.6 ± 12.6; p < 0.001), indicating poorer OHRQoL. In the bivariate analyses, poorer OHRQoL was also observed among current smokers, participants with diabetes mellitus, those with lower educational attainment, and those with lower socioeconomic status (p < 0.05). In the exploratory partially adjusted model, male sex (β = 4.2; 95% CI: 0.1–8.2; p = 0.042), diabetes mellitus (β = 6.5; 95% CI: 2.1–10.9; p = 0.004), and stage IV periodontitis (β = 4.6; 95% CI: 0.4–8.7; p = 0.031) were associated with higher OHIP-14-PD scores. Conclusions: In this single-center cross-sectional sample, patients with stage IV periodontitis reported higher OHIP-14-PD scores than those with stage II periodontitis. These findings indicate an association within the studied clinical population and should not be interpreted as evidence of a causal effect or as directly generalizable to broader populations. Larger multicenter longitudinal studies including patients across all periodontitis stages are required to confirm the magnitude and external validity of this association.

Background: Freehand direct composite resin veneers offer a minimally invasive approach for managing aesthetic alterations in anterior teeth; however, their long-term colour alteration and surface performance remain uncertain. This systematic review evaluated colour alteration, marginal discolouration, and surface-quality deterioration after at least 24 months of clinical service. Methods: MEDLINE/PubMed, Embase, Web of Science, Scopus, the Cochrane Library, and ClinicalTrials.gov were searched. Randomised and non-randomised trials and longitudinal clinical studies evaluating freehand direct anterior composite restorations were eligible. Risk of bias was assessed using RoB 2 and the JBI cohort checklist. Single-arm proportions were pooled separately using random-effects models with Freeman–Tukey transformation. Logit-REML models, binomial-normal generalised linear mixed models, Hartung–Knapp adjustments, leave-one-out analyses, and influence diagnostics were used as sensitivity analyses. Results: Eight studies were included. Colour alteration was evaluated in 893 restorations, with a pooled proportion of 14% (95% CI: 5–26%; I² = 95.0%). Marginal discolouration involved 566 restorations and yielded a pooled proportion of 21% (95% CI: 10–34%; I² = 91.8%). Surface-quality deterioration was assessed in 896 restorations, with a pooled proportion of 21% (95% CI: 9–35%; I² = 95.6%). GLMM estimates were 11%, 19%, and 18%, respectively. Hartung–Knapp and leave-one-out analyses produced compatible results, although prediction intervals were wide. No study materially altered the overall interpretation. Conclusions: The pooled proportions of recorded aesthetic deterioration were 14% for colour alteration, 21% for marginal discolouration, and 21% for surface-quality deterioration. However, between-study heterogeneity was substantial, and prediction intervals were wide (0–63%, 0–68%, and 0–74%, respectively), indicating considerable variability in the outcomes expected across clinical settings. Absence of recorded deterioration should not be interpreted as equivalent to overall aesthetic success or clinical acceptability. Accordingly, the pooled estimates should be interpreted cautiously and primarily as average estimates across heterogeneous clinical settings.

Background/Objectives: Periodontitis is a chronic inflammatory disease characterized by progressive destruction of the periodontal supporting tissues. Regenerative responses may vary according to patient-related biological characteristics, periodontal defect morphology, the local inflammatory microenvironment, cellular source, biomaterial selection, and delivery strategy. Cell-based regenerative therapies may therefore provide a biological foundation for the future development of personalized periodontal regenerative approaches. This systematic review and meta-analysis evaluated the effectiveness of cell-based therapies for periodontal regeneration and considered how the current evidence may inform future personalized regenerative strategies. Methods: A comprehensive electronic search was conducted in MEDLINE via PubMed, Web of Science, Embase, and the Cochrane Library, with additional searches performed in SciELO and Latindex, in accordance with PRISMA guidelines. Randomized and quasi-randomized controlled clinical trials evaluating cell-based regenerative therapies for periodontal defects were included. The primary outcomes were clinical attachment level (CAL) gain and probing depth (PD) reduction, while radiographic bone regeneration was considered a secondary outcome. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated using random-effects models. Leave-one-out sensitivity analyses were performed to assess the stability of the pooled estimates. Results: Six clinical trials were included in the qualitative synthesis, and five contributed to the quantitative analysis. Cell-based regenerative therapies showed a small, non-significant effect for CAL gain (SMD = 0.17; 95% CI: −0.12 to 0.45; I² = 0%) and PD reduction (SMD = 0.13; 95% CI: −0.22 to 0.48; I² = 33.0%). Radiographic bone regeneration showed a larger favorable effect, although statistical significance was not reached and substantial heterogeneity was present (SMD = 1.25; 95% CI: −0.08 to 2.58; I² = 88.2%). Leave-one-out analyses did not materially alter the non-significant interpretation for CAL or PD, although some variation in effect magnitude and direction was observed. Radiographic bone regeneration was more sensitive to the exclusion of individual studies. Overall, superiority of cell-based regenerative therapies over control interventions was not demonstrated. Risk-of-bias assessment indicated a low overall risk for most randomized trials, with some concerns in one trial and moderate risk in the quasi-randomized study. Conclusions: Cell-based regenerative therapies showed preliminary but inconclusive signals of benefit for periodontal regeneration. However, no statistically significant superiority over control interventions was demonstrated for CAL gain, PD reduction, or radiographic bone regeneration. Further well-designed clinical trials are required before these approaches can be considered for routine or personalized periodontal regenerative strategies.