Effect of fluoride mouthrinse and toothpaste on number of streptococcal colony forming units of dental plaque

Frequent topical fluoride therapy through toothpaste, mouthrinse, professional gels and solutions causes decrease in incidence, pause and repair of dental caries in the enamel. These mechanisms are done through penetration of fluoride ions [F-] and their replacement with hydroxyl ions [OH-] of hydroxyappatite of enamel, interfere with microbial metabolism of dental plaque and bacteriostatic effect on some cariogenic bacterial strains such as streptococci. The aim of this study was to examine the effect of fluoride mouthrinse and toothpaste on the number of streptococcal colony forming units of dental plaque. 62 children with 6-7 years old were put in two groups. Samples of dental plaque from each group were collected both before and after use of the fluoride mouthrinse and or toothpaste. The samples were cultured on blood agar to find the number of streptococcal colony forming units [CFU]. The mean colony forming unit was compared inter and intra groups before and after application of Fluoride products. The streptococcal CFU of dental plaque before and after use of the mouthrinse and toothpaste respectively was [1240 +/- 1367, 1253 +/- 1341.5] and [551 +/- 716, 898 +/- 1151]. Statistically, the streptococcal CFU in each group before and after use of the toothpaste and mouthrinse was significantly different. The findings of this study indicated that the fluoride toothpaste and mouthrinse reduce number of streptococcal colony forming units of dental plaque. Also this reduction was not depended on level of [F-] Ions, sort of vehicle of fluoride and frequent application of the fluoride mouthrinse and toothpaste

[Comparative evaluation of the sustainability of antibacterial effects of doxycycline, chlorhexidine and sodium hypochlirite in bovine root dentine]

One of the most important objectives of root canal therapy is the elimination of micro organisms from the root canal system. In order to achieve maximum disinfection of the root canal system, irrigation should be done during treatment. The aim of this in vitro study was to compare the sustainable antimicrobial activity of 2% chlorhexidine solution, 100 mg/ml doxycycline solution, and 2.6% NaOCL solution in bovine root dentine. Fifty dentine tubes prepared from intact freshly extracted bovine maxillary central incisors were infected invitro for 14 days with Enterococcus faecalis. The specimens were divided into five groups according to the intracanal irrigant used. Group1: 100mg/ml doxycycline hydrochloride solution [n=10]; Group2: 2% chlorhexidine gluconate solution [n=10]; Group 3: 2.6% NaOCL solution [n=10]; Group 4: Infected dentinal tubes [positive control] [n=10] and Group 5: Sterile dentinal tubes [negative control] [n=10]. Dentine chips were removed from the canal with sequential sterile round burs at low speed. The samples obtained with each bur were immediately collected in separate test tubes containing 1 ml tryptic soy broth [TSB]. Thereafter, 100 micro1 from each test tube was cultured on blood agar and number of CFUs was counted. The number of CFUs from three experimental groups were compared using Univariate analysis of variance [ANOVA] and Duncan analysis .Sustainable antimicrobial effect was evaluated at days 0,7,14 ,21 and 28. The number of CFUs in all three experimental groups were minimum in the first cultures, but the results obtained were significantly different from each other at any time period [P<0.05] .In the first culture, 2.6% NaOCL group [0.400 +/- 0.699]and 100 mg/ml doxycycline HCL group [4.700 +/- 3.683]showed the lowest and highest number of CFUs respectively . In each group, the number of CFUs increased significantly with time -lapse [p<0.05] .NaOCL did not have a sustainable effect. It can be concluded that chlorhexidine and to some extent, doxycycline HCL may be useful as sustainable antimicrobial root canal irrigants