Hadeel M Ayoub1,2,3, Richard L Gregory2, Qing Tang4, Frank Lippert5. 1. Dental Health Department, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia. 2. Department of Biomedical Sciences and Comprehensive Care, School of Dentistry, Indiana University, Indianapolis, IN, USA. 3. School of Medicine, Bowen Center for Health Workforce Research and Policy, Indiana University, Indianapolis, IN, USA. 4. Department of Biostatistics, School of Medicine, Indiana University, Indianapolis, IN, USA. 5. Department of Cariology, Operative Dentistry and Dental Public Health, School of Dentistry, Indiana University, 415 Lansing Street, Indianapolis, IN, 46202-2876, USA. flippert@iu.edu.
Abstract
OBJECTIVES: (1) To explore the influence of biofilm maturation and timing of exposure on fluoride anticaries efficacy and (2) to explore biofilm recovery post-treatment. METHODS: Bovine enamel specimens were utilized in a pH cycling model (28 subgroups [n = 18]). Each subgroup received different treatments [exposure]: sodium fluoride [NaF]; stannous fluoride [SnF2]; amine fluoride [AmF]; and de-ionized water [DIW], at a specific period: early: days 1-4; middle: days 3-6; and late: days 7-10. During non-exposure periods, pH cycling included DIW instead of fluorides. Objective 1: part 1 (cycling for 4, 6, or 10 days). Part 2 (cycling for 10 days). Objective 2: early exposure: three sample collection time points (immediate, 3 days, and 6 days post-treatment); middle exposure: two sample collection time points (immediate, 4 days post-treatment). The enamel and biofilm were analyzed ([surface microhardness; mineral loss; lesion depth]; [lactate dehydrogenase enzyme activity; exopolysaccharide amount; viability]). Data were analyzed using ANOVA (p = 0.05). RESULTS: Objective 1: Early exposure to fluorides produced protective effects against lesion progression in surface microhardness and mineral loss, but not for lesion depth. Objective 2: Early exposure slowed the demineralization process. SnF2 and AmF were superior to NaF in reducing LDH and EPS values, regardless of exposure time. They also prevented biofilm recovery. CONCLUSION: Earlier exposure to SnF2 and AmF may result in less tolerant biofilm. Early fluoride treatment may produce a protective effect against demineralization. SnF2 and AmF may be the choice to treat older biofilm and prevent biofilm recovery. CLINICAL RELEVANCE: The study provides an understanding of biofilm-fluoride interaction with mature biofilm (e.g., hard-to-reach areas, orthodontic patients) and fluoride's sustainable effect hours/days after brushing.
OBJECTIVES: (1) To explore the influence of biofilm maturation and timing of exposure on fluoride anticaries efficacy and (2) to explore biofilm recovery post-treatment. METHODS: Bovine enamel specimens were utilized in a pH cycling model (28 subgroups [n = 18]). Each subgroup received different treatments [exposure]: sodium fluoride [NaF]; stannous fluoride [SnF2]; amine fluoride [AmF]; and de-ionized water [DIW], at a specific period: early: days 1-4; middle: days 3-6; and late: days 7-10. During non-exposure periods, pH cycling included DIW instead of fluorides. Objective 1: part 1 (cycling for 4, 6, or 10 days). Part 2 (cycling for 10 days). Objective 2: early exposure: three sample collection time points (immediate, 3 days, and 6 days post-treatment); middle exposure: two sample collection time points (immediate, 4 days post-treatment). The enamel and biofilm were analyzed ([surface microhardness; mineral loss; lesion depth]; [lactate dehydrogenase enzyme activity; exopolysaccharide amount; viability]). Data were analyzed using ANOVA (p = 0.05). RESULTS: Objective 1: Early exposure to fluorides produced protective effects against lesion progression in surface microhardness and mineral loss, but not for lesion depth. Objective 2: Early exposure slowed the demineralization process. SnF2 and AmF were superior to NaF in reducing LDH and EPS values, regardless of exposure time. They also prevented biofilm recovery. CONCLUSION: Earlier exposure to SnF2 and AmF may result in less tolerant biofilm. Early fluoride treatment may produce a protective effect against demineralization. SnF2 and AmF may be the choice to treat older biofilm and prevent biofilm recovery. CLINICAL RELEVANCE: The study provides an understanding of biofilm-fluoride interaction with mature biofilm (e.g., hard-to-reach areas, orthodontic patients) and fluoride's sustainable effect hours/days after brushing.
Authors: Constanza E Fernández; Margherita Fontana; Derek Samarian; Jaime A Cury; Alexander H Rickard; Carlos González-Cabezas Journal: Caries Res Date: 2016-04-14 Impact factor: 4.056
Authors: Marlise I Klein; Lena DeBaz; Senyo Agidi; Herbert Lee; Gary Xie; Amy H-M Lin; Bruce R Hamaker; José A Lemos; Hyun Koo Journal: PLoS One Date: 2010-10-19 Impact factor: 3.240
Authors: Marlise I Klein; Geelsu Hwang; Paulo H S Santos; Osvaldo H Campanella; Hyun Koo Journal: Front Cell Infect Microbiol Date: 2015-02-13 Impact factor: 5.293