[ experimental micro leakage study of two self-etch and one total-etch fissure sealants]

The extreme vulnerability to decay in pits and fissures on the occlusal surfaces of the teeth has prompted dental scientists to seek methods of caries prevention. Various criteria, such as bond strength, micro leakage and marginal seal are assessed in the evaluation of sealants. Motivated by the role of pit and fissure sealants in caries prevention, the aim of this study was to compare the micro leakage of Enamel Loc sealant, Concise and Concise +Prompt L-pop resin-based sealants. An in vitro study was undertaken using thirty extracted third molars. The teeth were divided into three groups; an experimental group using Enamel Loc as a pit and fissure sealant, a group using Concise and a group using Concise +Prompt L-pop. The teeth were kept in methylene blue dye 2% for 4 hours, sectioned samples were observed with stereomicroscope for the extent of dye penetration and scores were based on Williams and Winter criteria. Three groups of data were statistically analyzed using SPSS 18. Non-parametric Kruskal-Wallis test was used to detect differences among groups [p>0/001]. The Enamel Loc sealant micro leakage was significantly more than the two other groups [p>0/001]. Furthermore, Concise micro leakage was significantly less than Concise +Prompt L-pop group [p>0/001]. The Enamel Loc sealant performed worse in terms of sealing ability than the Concise and Concise +Prompt L-pop resin-based sealants

Comparison of plaque removal efficacy of new and 3-month-old toothbrushes in children

The cost of replacing toothbrushes at frequent intervals may be prohibitive in underdeveloped countries. The objective of this study in Tehran was to compare the plaque removal efficacy of new and 3-month-old toothbrushes in children. In a randomized, crossover study, 93 children aged 7-9 years old received a new manual toothbrush to use twice per day for 3 months. Plaque scores were measured using the modified Quigley-Hein plaque index after children had brushed for 60 seconds with either a new or their used toothbrush. Bristle wear of worn brushes was assessed by measuring brushing surface areas on digital images. Compared with new brushes in the same subjects, no statistically significant differences were found for plaque score reductions for 3-month-old toothbrushes exhibiting various degrees of wear. Worn toothbrushes are equally effective as new ones for children

[Fluoride retention in saliva following toothbrushing with two Iranian fluoride dentifrices, Nasim and Crend in comparison with sample dentifrices]

The presence of fluoride in oral fluids, is necessary for prevention of dental caries. The aim of this study was to determine the extent of fluoride retention in saliva after brushing with two Iranian fluoridated toothpastes, Nasim and Crend in comparison with MacLeans and Crest. Ten adults used a nonfluoride dentifrice for 10 days before the experiment and between different stages of the experiment. The dentifrices included Nasim and MacLeans [with sodium monofluorophosphate] and Crend and Crest [with sodium fluoride]. In each procedure, participants brushed their teeth with 1.5 gr of the dentifrices under trial for 1 minute. Saliva samples were collected at baseline, 1, 30, 60; 120 minutes after tooth brushing and fluoride ion were measured by potentiometry technique. The data were analyzed by Repeated Measurements, Paired t, One Way ANOVA and Tukey tests. All dentifrices under this trial, had the highest fluoride concentration in saliva 1 minute after brushing [P<0.005] and after that time fluoride concentration decreased gradually. Crest toothpaste in comparison with Crend had higher fluoride retention in the 60 and 120 minutes [60 minutes: [0.9824 +/- 0.0988, 0.5173 +/- 0.770] [P<0.005]; 120 minutes: [0.8103 +/- 0.0615, 0.3651 +/- 0.0580] [P<0.008]]. The Crest dentifrice showed the most fluoride retention in saliva, MacLeans and Nasim dentifrices had similar values of fluoride retention while the Crend dentifrice showed the least values of fluoride retention

[ comparison on fluoride uptake rates in the enamel of permanent teeth after application of Cina and ADA standard gel [Sultan]]

Background and aim: periodic and regular fluoride therapy significantly reduces caries prevalence in children and adolescents. Nowadays, a lot of different kinds of fluoride gels are used in the dental office and determination of fluoride ion uptake rate by enamel is a good way to evaluate the efficacy of these products. The aim of this experimental study was to compare fluoride ion uptake rate by the enamel of permanent teeth after the application of "Cina" gel and an ADA standard gel [Sltan]

Methods and Materials: forty intact permanent premolars Nere divided into buccal and lingual halves - with diamond disks under to water. Buccal halves were considered as cases [Fluoride-applied] and lingual ones as controts. A half-circle [6mm diameter] adhesive tape was applied to the enamel surface and other parts were then covered with acid-resistant polish. After adhesive tapes removal twenty buccal halves were exposed to "Cina and the others to "Sultan" gel. After four minutes, the specimens were suspended in 5ml synthetic saliva for 24hours at 37 degree C. Afterwards, each specimen was etched for 30 seconds in lcc of 0.5M Acid Percholoric in two sequential stages and in each stage, the window was washed with 0.2M KOH solution. Measurements of fluoride and calcium concentrations were carried out using Potentiometer and Atomic absorption spectrophotometry, respectively. Data were subjected to Paired t-test, Mann-Whitney U test and wilcoxon Signed Rank test

Results: results showed that mean fluoride concentration of cases was significantly higher than controls in "Sultan" group [1824.4 ppm vs. 1449.6 ppm, P=0.000 in the first layer of biopsy and 2032.5 ppm VS. 1310.5 ppm, P=0.000 in the second layer]. In Cina gel group, there were no significant differences in fluoride concentration of two biopsy layers in cases and controls [1521.7 ppm vs. 1450.3 ppm, P=0.316 in the first layer and 1385.8 ppm vs. 1357.6 ppm, P=0.951 in the second]. In both layers, the mean fluoride uptake rates were higher in "Sultan" than "Cina" group [392.8 ppm vs. 71.4 ppm, P=0.000 in the first layer and 722.1 ppm vs. - 1.7 ppm, P=0.000 in the second layer]

Conclusion: considering the insufficient uptake rate of fluoride ion in "Cina" gel, it is suggested that lhisgel has no efficiency in increasing enamel fluoride content