The effect of post brushing mouthrinses on salivary fluoride retention, and, The effect of varying fluoride concentration on remineralisation of bovine enamel in vitro

• Main Author: Shaw, Karen
• Format: Dissertation
• Language: English
• Published: University of Liverpool 2015
• Subjects: RK Dentistry
• DOI: 10.17638/02007510

The effect of post-brushing mouthwashes on salivary fluoride retention. Objective: To assess the effect of post-brushing mouthwashes on salivary fluoride retention. Methods: This was a three phase cross over study with thirty participants. Salivary F levels were measured before brushing with a 1450 ppm F toothpaste (Time 0) and after brushing, rinsing with water and then with one of either 0,225 or 500 ppm F mouthwash at time points 1,3,5,10,20,45,60 minutes using an ion-specific electrode. Results: Significant differences in mean fluoride retention over the 60 minute period were found for all three pair wise groups using paired t tests (p<0.001). A 2660% increase in salivary fluoride retention over the 60 minutes was found with the 500 ppm F mouthwash when compared with the 0 ppm F group. With the 225 ppm F group a 120% increase was found. Conclusion: The use of a fluoride mouthwash containing 225 ppm or 500 ppm produced a significant increase in salivary fluoride retention following brushing with 1450 ppm F toothpaste and rinsing with water. The use of the 500 ppm F mouthwash may be of particular benefit to those at high caries risk including orthodontic patients. The effect of varying fluoride concentration on remineralisation of bovine enamel in vitro. Objective: To assess the effect of varying fluoride concentration on the remineralisation of bovine enamel in vitro using the techniques of quantitative light induced fluorescence (QLF – D), multispectral imaging (MSI) and transverse microradiography (TMR). Methods: artificially produced enamel carious lesions were produced following immersion in demineralisation solution (pH 4.5) for 72 hours. Baseline analysis was carried out with quantitative light induced fluorescence (QLF – D), multispectral imaging (MSI) and transverse microradiography (TMR). Samples were then randomised, using a computer generated randomisation sequence to one of 5 groups for remineralisation: 0 ppm, 225 ppm, 500 ppm, 1450 ppm or 2800 ppm Fluoride. The experimental phase lasted for eight weeks with weekly imaging with QLF-D and MSI. A post remineralisation phase of TMR was then carried out. Results: Reliable results were obtained for QLF-D and MSI only due to problems with the preparation of the baseline TMR samples. The results from QLF-D and MSI indicated a significant change in mineral loss occurred over the eight week period. Groupwise differences were shown between the 2800 ppm group and the remaining groups only. However, this was in a negative direction indicating mineral loss not gain as would have been anticipated. It is likely that a true remineralisation process was not replicated in this study. However in comparison of QLF-D and MSI techniques moderate correlation between the results was seen. MSI found greater differences and at an earlier stage than QLF-D. Conclusion: No remineralisation effect was seen in this study. Moderate correlation between the QLF-D and MSI results was demonstrated with greater differences detected with MSI.