Local delivery of hyaluronan and minocycline as an adjunct to subgingival instrumentation in the treatment of stage II grade B diabetic periodontitis: a randomized split-mouth clinical and microbiological study

Objectives: For treating stage II grade B periodontitis in controlled type 2 diabetes, this study compared the clinical and microbiological effectiveness of adjunctive 2% minocycline and 0.2% hyaluronan gels in combination with subgingival instrumentation versus subgingival instrumentation alone. Methods: Twenty patients were divided into two groups: group I (hyaluronan and minocycline gel with subgingival instrumentation vs. placebo with subgingival instrumentation) and group II (hyaluronan and minocycline gel alone vs. placebo with subgingival instrumentation). Using a split-mouth design, subgingival plaque samples were analysed for Porphyromas gingivalis (P gingivalis) and Prevotella intermedia (P intermedia) at baseline and one month after treatment. Clinical parameters such as plaque index (PI), gingival index (GI), bleeding on probing (BOP), periodontal pocket depth (PPD), and clinical attachment level (CAL) were evaluated at baseline and three months after treatment. Results: In Group I, the clinical improvements were significant in sites treated with subgingival instrumentation and the hyaluronan–minocycline gel than with subgingival instrumentation and placebo, with a mean decrease in PPD 2.1 ± 0.4 mm versus 1.2 ± 0.3 mm and a mean increase in CAL 1.9 ± 0.3 mm versus 1.0 ± 0.2 mm (p < 0.01 for both). Microbiologically, these sites also showed a 63% greater reduction in the level of P. gingivalis (p < 0.01). In Group II, the use of subgingival instrumentation and placebo yielded better clinical outcome measures for PPD and CAL (p < 0.05) than for gel monotherapy, although gel-only sites showed a minor but significant reduction in the level of P. gingivalis (p < 0.05). Conclusion: The adjunctive application of hyaluronan–minocycline gel with subgingival instrumentation showed significant short-term improvements in periodontal outcomes compared with subgingival instrumentation alone, indicating a beneficial supportive effect for type 2 diabetics with Stage II, Grade B periodontitis. In contrast, gel monotherapy showed limited clinical efficacy, despite some microbiological reduction, underscoring that mechanical debridement remains essential and that local antimicrobials should be used only as adjuncts rather than monotherapy. Further long-term studies with larger samples are warranted. Clinical relevance: Adjunctive use of locally delivered hyaluronan–minocycline gel with subgingival instrumentation significantly improves periodontal healing and reduces key pathogens in type 2 diabetic patients, where conventional therapy alone may be inadequate.