Sufian A Yassin1, Matthew J German2, Sarah L Rolland3, Alexander H Rickard4, Nicholas S Jakubovics5. 1. School of Dental Sciences, Centre for Oral Health Research, Newcastle University, Newcastle upon Tyne NE2 4BW, UK. Electronic address: drsufian2005@yahoo.com. 2. School of Dental Sciences, Centre for Oral Health Research, Newcastle University, Newcastle upon Tyne NE2 4BW, UK. Electronic address: matthew.german@newcastle.ac.uk. 3. School of Dental Sciences, Centre for Oral Health Research, Newcastle University, Newcastle upon Tyne NE2 4BW, UK. Electronic address: s.l.rolland@newcastle.ac.uk. 4. Department of Epidemiology, University of Michigan, Ann Arbor, MI 48109-2029, USA. Electronic address: alexhr@umich.edu. 5. School of Dental Sciences, Centre for Oral Health Research, Newcastle University, Newcastle upon Tyne NE2 4BW, UK. Electronic address: nick.jakubovics@newcastle.ac.uk.
Abstract
OBJECTIVES: This study aimed to develop a new mixed-species acidogenic biofilm model and use it to assess the antimicrobial properties of a novel fluoride-releasing copolymer. METHODS: Stubs composed of a copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) with polymethyl methacrylate (PMMA) were produced by chemically-activated free radical polymerization. A fluoride-releasing copolymer was developed by incorporating sodium fluoride in place of a portion of the PMMA. Samples were mounted in polysulfone Modified Robbins Devices (MRDs) and were optimized for single- and mixed-species biofilm formation by Candida albicans, Lactobacillus casei and Streptococcus mutans. RESULTS: Fluoride release was sustained for at least 48h in flowing conditions. Fluoride did not affect the colonization and biofilm growth of any of the microorganisms in monocultures. However, in mixed-species biofilms, cell densities of all three species were reduced approximately ten-fold (p<0.05) on the fluoridated material compared with the non-fluoridated copolymer. CONCLUSIONS: These data demonstrate that intermicrobial interactions in mixed-species acidogenic biofilms are sensitive to fluoride, and that the inclusion of fluoride in a denture lining copolymer reduces the formation of polymicrobial biofilms. CLINICAL SIGNIFICANCE: The growth of acidogenic microorganisms on denture materials is associated with denture stomatitis and dental caries on surrounding teeth. A fluoride-releasing copolymer that inhibits acidogenic mixed-species biofilms, such as the material described in this study, has the potential to control these diseases by limiting biofilm growth.
OBJECTIVES: This study aimed to develop a new mixed-species acidogenic biofilm model and use it to assess the antimicrobial properties of a novel fluoride-releasing copolymer. METHODS: Stubs composed of a copolymer of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA) with polymethyl methacrylate (PMMA) were produced by chemically-activated free radical polymerization. A fluoride-releasing copolymer was developed by incorporating sodium fluoride in place of a portion of the PMMA. Samples were mounted in polysulfone Modified Robbins Devices (MRDs) and were optimized for single- and mixed-species biofilm formation by Candida albicans, Lactobacillus casei and Streptococcus mutans. RESULTS:Fluoride release was sustained for at least 48h in flowing conditions. Fluoride did not affect the colonization and biofilm growth of any of the microorganisms in monocultures. However, in mixed-species biofilms, cell densities of all three species were reduced approximately ten-fold (p<0.05) on the fluoridated material compared with the non-fluoridated copolymer. CONCLUSIONS: These data demonstrate that intermicrobial interactions in mixed-species acidogenic biofilms are sensitive to fluoride, and that the inclusion of fluoride in a denture lining copolymer reduces the formation of polymicrobial biofilms. CLINICAL SIGNIFICANCE: The growth of acidogenic microorganisms on denture materials is associated with denture stomatitis and dental caries on surrounding teeth. A fluoride-releasing copolymer that inhibits acidogenic mixed-species biofilms, such as the material described in this study, has the potential to control these diseases by limiting biofilm growth.