Development of caries adjacent to composite restorations after exposure to dentifrices with different fluoride concentrations

Dayse Andrade Romão,Guilherme José Pimentel Lopes De Oliveira,Lucineide De Melo Santos,José Ivo Limeira Dos Reis

doi:10.1590/1807-2577.1014

Abstract

Objective To evaluate the development of recurrent caries after exposure to fluoride dentifrices with different concentrations. Material and method: 48 samples of bovine incisors (4x4mm2) were exposed to pH cycling for 7 days before the preparation of the cavities (2mm deep). The samples were restored with a microhybrid resin composite. Then, the samples were exposed to thermal cycling (350 cycles) and they were randomly allocated into 4 treatment groups (n = 12): Group A - non-fluoridated dentifrice (negative control); Group B - 500 ppm dentifrice; Group C - 750 ppm dentifrice; group D - 1100 ppm dentifrice (positive control). The samples were treated with solutions of each dentifrice (9.6 ml water/1.6 g dentifrice) for 60 seconds and then were immersed in demineralizing (3 h) and remineralizing (2 h) solutions 3 times a day. Next, the samples were immersed in a remineralizing solution for 18 hours. Then, the blocks were sectioned for examination of the length of the outer caries lesion, using polarized light microscopy. The ANOVA parametric test complemented by the Tukey test with a confidence level of 95%, were used in the statistical analysis. Result: A smaller lesion length was observed in the group treated with the fluoride concentration of 1100 ppm F, but there were no differences between toothpastes with fluoride concentrations of 500 and 750 ppm F. Conclusion: The use of fluoride dentifrices (1100 ppm) reduces the development of caries adjacent to dental restorations.

Highlights

The use of fluoride is considered one of the most effective methods for the control of dental caries because it interferes with the dynamics of the carious process, acting to inhibit demineralization and strengthening remineralization[1,2]
The excessive use of fluoride may cause toxic reactions such as dental fluorosis, which is considered a systemic effect secondary to the chronic, total ingestion and absorption of fluoride and which depends on the amount of fluoride in the dentifrice, the length of exposure, the stage of tooth development, the moment of exposure and variations in individual susceptibility[6]
In the comparisons between the different treatments, the group exposed to the non-fluoridated solution (Group A) showed the greatest depth of caries in the enamel (p

Summary

INTRODUCTION

The use of fluoride is considered one of the most effective methods for the control of dental caries because it interferes with the dynamics of the carious process, acting to inhibit demineralization and strengthening remineralization[1,2]. Dentifrices with low concentrations of fluoride have been suggested for children, but the efficacy of these products in the formation of recurrent caries has received little attention in spite of the data, from SB Brasil 2010, demonstrating that children up to 5 years of age present 13.6% of the dental fillings and by 12 years of age the number of filled teeth increases to 35.3%11. For this reason, the purpose of this study was to evaluate the development of caries adjacent to composite resin restorations after exposure to fluoridated dentifrices of different concentrations

MATERIAL AND METHOD

RESULT

DISCUSSION

Findings

CONCLUSION