Long-term efficacy of Magnolia Bark Extract and Xylitol administered through chewing gums on caries in adults: A 2-year randomized controlled intervention trial

Caries preventive effect of a sugar-free chewing-gum containing Magnolia Bark Extracts and Xylitol in high-risk adults was investigated (NCT02310308). Two-hundred seventy-one high-caries-risk subjects were assigned to three groups: Polyols (Pols), Xylitol (Xyl) and Xylitol plus Magnolia (Xyl + Mag). Caries lesions, gingival bleeding, mutans streptococci (MS), and plaque pH were re-evaluated after 2 years in 64 Pols, 66 Xyl and 64 Xyl + Mag subjects. Net caries increment was evaluated using the Mann–Whitney U test. Caries increment was significantly different among groups at the 2-year evaluation (t3) (p < 0.01). MS concentration and plaque pH as mean Areas Under the Curves (AUC) differed among groups at t2 (MS p = 0.02, AUC5.7 p = 0.03 and AUC6.2 p = 0.04,) and t3 (p = 0.03, p = 0.04 and 0.05, respectively). Significantly lower gingival scores were observed in Xyl + Mag and Xyl groups (p = 0.01 and<0.01, respectively). Chewing-gum containing Xylitol and Magnolia has a higher preventive effect compared to Xylitol alone.