Effect of Magnolia Bark Extract on Plaque Accumulation in vivo

Methods: A 4-leg double blind cross-over study with 12 healthy volunteers consuming 4 formulations of sugar-free pressed mints (Placebo, MBE, CBO, CBO+MBE) 5 times a day, while refraining from oral hygiene for 5 days. All test formulations of pressed mints contained sodium lauryl sulphate. QLF images of buccal surfaces of upper and lower anterior teeth (canine to canine) were analysed for plaque by the presence of red fluorescence (RF).

Results: One volunteer withdrew from the study. There was a significant difference observed between experimental groups in intensity of red fluorescence (ΔR) using repeated measures ANOVA (n=11, p=0.018) with the lowest ΔR detected in MBE group (36.8 ± 3.7%) followed by MBE+CBO (37.8 ± 3.1%), CBO (38.6 ± 4.2%) and placebo (40.9 ± 3.9%). Paired t-tests for post-hoc comparisons demonstrated significant differences only in MBE vs. placebo (p=0.012) and MBE+CBO vs. placebo (p=0.031) pairs. No difference was noticed in area of RF (repeated measures ANOVA, n=11, p=0.08), however, similar trends for ΔR were found with the lowest plaque area coverage for MBE (119.7 ± 43.9 mm²) followed by MBE+CBO (143.6 ± 58.4 mm²), CBO (144.3 ± 54.6 mm²) and placebo (154.5 ± 52.5 mm²), with paired t-tests post-hoc comparisons significant for MBE vs. placebo (p=0.025) and MBE vs. CBO (p=0.022).

Conclusion: Consuming pressed mints containing MBE led to a reduction in dental plaque accumulation on labial surfaces of anterior teeth in this in vivo study quantified as ΔR using QLF.

The study was sponsored by Wm WRIGLEY Jr Company.