Innovative herbal oil formulation as a pre-prosthetic mucosal conditioner: a prospective controlled cytological study on the degree of keratinization in edentulous ridge mucosa before and after Its topical application

Abstract

Background Adequate keratinization of the edentulous ridge is fundamental for denture support, retention, stability, and mucosal resilience. This study evaluated the effect of topical Moringa oleifera stem bark oil on oral mucosal keratinization in edentulous ridges using a prospective controlled clinical trial design with a water-massage control group. Methods One hundred and eight completely edentulous participants were enrolled between April 2025 and September 2025: a treatment group (n = 54) received twice-daily topical Moringa oleifera stem bark oil for four weeks, and a control group (n = 54) received twice-daily water massage of the same ridge area. Exfoliative cytology was performed at baseline (T0), Week 2 (T2), and Week 4 (T4). The in vitro cytocompatibility of the oil was additionally evaluated in human keratinocyte (HaCaT) cells using the MTT assay, performed in three independent experiments (biological triplicate), each with three technical replicates per concentration. Statistical analyses included the Friedman test (within-group temporal changes), the Wilcoxon signed-rank test with Bonferroni correction (post-hoc pairwise comparisons), and the Mann–Whitney U test (between-group comparisons) for the clinical cytology data. Effect sizes are reported as Kendall's W and rank-biserial correlation (r). Results The treatment group demonstrated a significant progressive increase in superficial keratinized cells, from a median of 57.5 at T0 to 114.0 at T4 [Friedman χ2(2) = 59.40, p < 0.001, Kendall's W = 0.632]. Post-hoc Wilcoxon analysis confirmed significant improvements at each interval (all Bonferroni-corrected p < 0.001, r = 0.615–0.796). The control group showed no significant temporal change in superficial cells (Friedman p = 0.162, Kendall's W = 0.037). Between-group differences became more pronounced over time: superficial cell counts were not significantly different at baseline (p = 0.433), diverged at Week 2 (p = 0.002, r = 0.319), and were highly significantly different at Week 4 (p < 0.001, r = 0.777). The MTT assay (three independent experiments, each with technical triplicates; n = 3 per concentration) showed that the oil was non-toxic to HaCaT keratinocytes at concentrations up to 50 μg/mL. Mean cell viability trended higher than the untreated control in a concentration-dependent manner; however, this comparison was descriptive only, as no inferential statistical test was applied to the in vitro dataset, and the apparent trend should not be interpreted as a statistically confirmed effect. No adverse reactions were observed clinically. Conclusion Topical Moringa oleifera stem bark oil was associated with a significant increase in cytological markers of keratinization, with no change in the water-massage control group, and descriptively demonstrated favourable in vitro cytocompatibility, with viability trending higher than control across tested concentrations (mean ± SD, three independent experiments); this in vitro trend was not evaluated by inferential statistics and warrants confirmation with formal statistical comparison in future work. These findings suggest promising potential as a pre-prosthetic mucosal conditioning approach, pending confirmation in larger, randomized, placebo (vehicle)-controlled trials with longer follow-up, histological verification, and patient-centred outcomes. Clinical Trial Registration: CTRI/2025/04/084650; Patent Publication No. 202241052361. Clinical Trial Registration (https://ctri.nic.in) CTRI/2025/04/084650; Patent Publication No. 202241052361.