The Role of Hyaluronic Acid in the Treatment of Gingivitis and Periodontitis at Different Stages: A Systematic Review and Meta-Analysis with Short-Term Follow-Up.

Periodontal diseases are inflammatory conditions that destroy the periodontal attachment apparatus. Hyaluronic acid (HA) has anti-inflammatory properties that make it a candidate for the adjuvant treatment of gingivitis and periodontitis. Our objective was to observe the role of HA in the variability of clinical parameters indicative of gingivitis/periodontitis by comparing it with conventional treatments or placebo. This systematic review and meta-analysis was conducted according to Cochrane guidelines, and searches were performed in PubMed, Embase, Cochrane Central, Scopus, and Web of Science (WOS) to identify eligible studies. Review Manager 5.4.1 and SPSS Statistics 30.0® were used to calculate standardized mean differences (SMDs) and 95% confidence intervals (CIs). The outcomes assessed were probing depth (PPD), bleeding on probing (BOP), clinical attachment level (CAL), plaque index (PI), and gingival index (GI). Sixteen randomized clinical trials (RCTs) with 947 subjects were included. HA as an adjunct to periodontal treatment improves the clinical parameters of PPD in the short and medium term (1-24 months, 12.5 average) (-0.51; 95% CI [-0.85 to -0.17]; p = 0.004), BOP, CAL and GI. Plaque indices (PI) approached statistical significance. Despite limitations and heterogeneity, the evidence reveals that only two of the included studies on severe periodontitis reported significant improvements in CAL gain and PPD reduction, with attachmet gains greater than 1 mm at 12 months of follow-up.