Influence of plaque-promoting gauze on in situ remineralisation

Objectives: To compare remineralisation by chewing sugar-free (SF) gum with or without CPP-ACP with the enamel lesions exposed to usual dietary intake and some covered with gauze to promote plaque formation. Methods: This was a double-blind, randomised, cross-over study. Participants (n=9) wore removable palatal appliances containing three recessed enamel half-slabs with subsurface lesions covered with gauze and three without gauze. They were randomly assigned to a CPP-ACP SF gum, regular SF gum, or no gum control for each 2wk test period. Mineral content was measured by transverse microradiography and plaque composition was analysed by real-time polymerase chain reaction. Results: For both the gauze-free and gauze-covered lesions, the greatest amount of remineralisation was produced by the CPP-ACP SF gum (14.6 ± 6.0%, 13.5 ± 4.8%) , followed by the gum without CPP-ACP (6.5 ± 2.2%, 3.7 ± 5.3%) and the no-gum control (1.3 ± 2.5%, -3.6 ± 5.4%). Recessing the enamel in the appliance allowed plaque accumulation without the need for gauze. There was a trend of less remineralisation and greater variation in mineral content for the gauze-covered lesions. The cell numbers of total bacteria and streptococci were slightly higher in the plaque from the gauze-covered enamel for two of the three treatment legs; however there was no significant difference in S. mutans cell numbers. Conclusion: Chewing sugar-free gum containing CPP-ACP promoted greater levels of remineralisation than a sugar-free gum without CPP-ACP or a no-gum control using an in situ remineralisation model including dietary intake irrespective of whether gauze was used to promote plaque formation. Acknowledgements: The support of Kraft-Adams Worldwide Research and Development and the technical assistance of Greg Hanson are gratefully acknowledged.