Assessment of Oral Hygiene Practices, Adjunctive Cleaning Methods, and Their Impact on Plaque and Gingival Indices Among Young Adults in Urban and Rural Settings in Romania

Background/Objectives: Young adults increasingly prefer natural dentifrices; however, the short-term clinical effects and behavioural correlates of these products remain insufficiently documented. This study aimed to evaluate the associations between daily oral-hygiene practices, adjunctive cleaning methods, and plaque and gingival indices, and to compare the short-term effects of three natural toothpaste formulations—sodium bicarbonate, activated charcoal, and lemon-based. Methods: In this cross-sectional study, 101 Romanian adults (aged 20–41 years; 69.3% urban) completed a structured questionnaire assessing brushing frequency and the use of dental floss, interdental stimulators, and mouth rinses. Clinical assessments included the Silness–Löe Plaque Index and the Löe–Silness Gingival Index (modified by Lobene), recorded immediately before and after a supervised 2 min brushing session using the Bass technique with soft-bristled brushes and the participant’s self-reported natural toothpaste (baking soda: n = 42; charcoal: n = 27; lemon: n = 32). Results: Before brushing, 78.2% of participants presented with thin adherent plaque, while the gingival status was normal in 72.3%, mildly inflamed in 22.8%, and moderately inflamed in 5.0%. After brushing, the proportion with normal gingiva increased to 77.2%, and the proportion of thin, adherent plaque decreased to 22.8%. Brushing frequency was positively correlated with plaque reduction (ρ = 0.42, p < 0.001), while the use of adjunctive cleaning methods was inversely correlated with post-brushing gingival inflammation (ρ = −0.36, p = 0.002). Gingival improvement differed significantly among toothpaste types (χ2, p < 0.001), with formulations containing baking soda and lemon showing slightly more favourable short-term gingival categories than charcoal; these patterns are descriptive and do not demonstrate comparative product efficacy. Urban–rural differences were observed for brushing frequency (p < 0.001) and periodontal status with fewer lesions among urban participants (p = 0.002). Conclusions: A single supervised Bass-technique brushing session resulted in measurable short-term improvements in plaque and gingival indices among young adults. Sodium bicarbonate and lemon-based dentifrices appeared to be associated with slightly more favourable short-term gingival responses than charcoal, although these findings should be interpreted as preliminary. These findings emphasise the importance of consistent brushing and interdental cleaning behaviours and highlight the need for longitudinal randomised trials to evaluate the durability, safety, and comparative effectiveness of natural versus conventional dentifrices. Given the cross-sectional, single-session design, these findings are exploratory and do not establish causal or comparative product efficacy.