RESUMEN
Background: There is a need to monitor the fluoride content of dentifrices used for children in a country like India, where there is prevalence of endemic fluorosis. Aim: To evaluate the fluoride content of dentifrices for children available in India. Settings and Design: In vitro study in a laboratory setting. Methods: About 27 major supermarkets/departmental stores in Chennai city were approached by the investigator. All dentifrices indicated for children, available in these stores were included in the present study. A total of four different dentifrice brands were procured from these outlets. For each brand of dentifrice, three samples were randomly chosen and used for fluoride analysis. The fluoride content was assessed in triplet by using spectrophotometric analysis, by a single blinded examiner. The test sample was compared to a standard solution, in a calibration curve to determine the fluoride concentration. Results: The mean fluoride content of dentifrices, indicated for children was 449.5 ± 26.1 ppm. Conclusions: All brands of commercially available dentifrices indicated for children had optimum amount of fluoride.
RESUMEN
AIM AND OBJECTIVE: To compare and analyze the cyclic fatigue resistance of novel TruNatomy files against the conventionally used rotary files and reciprocating files in a simulated canal system with curvatures in the middle, apical portions root, and S-shaped canal employing scanning electron microscopy. MATERIALS AND METHODS: Endodontic files tested in the study include ProTaper, HyFlex EDM, Reciproc blue, and TruNatomy files operated in a simulated root canal system. A total of 96 files were employed in this study. They were categorized into four groups. Group 1 employed 24 TruNatomy files, group 2 employed 24 ProTaper gold files, group 3 employed 24 HyFlex EDM files, and group 4 employed 24 Reciproc blue files. All the groups employed eight files each under three subgroups namely A, B, and C representing middle, apical, and double curvatures, respectively. Artificial grooves were incorporated in the stainless steel blocks having three different curvatures. All the file systems were operated with a torque-controlled electric motor. The files were engaged in the artificial canal until the occurrence of fracture. The time required for the fracture was noted. Length of fractured tip was measured using the digital Vernier caliper. The number of cycles of failure (NCF) was calculated. The fractured parts were subjected to scanning electron microscope to analyze the mode of fracture. RESULTS: TruNatomy files had the highest mean NCF values of 588.01 in middle curvature, 1,321 in apical curvature, and 642.5 in S-shaped curvature HyFlex EDM and Reciproc blue file system exhibited comparable cyclic fatigue resistance among them. ProTaper gold file system exhibited least mean NCF values of 158.13 in the middle, 196.5 in the apical curvature, and 116.88 in the S-shaped canal system. Middle portion fractured first than the apical curvature. The mean length of fractured segments was found to be insignificant among the experimental study groups tested. CONCLUSION: All the file systems employed in the study had good cyclic fatigue resistance while TruNatomy files had the highest cyclic fatigue resistance while HyFlex EDM and Reciproc blue had comparable fatigue resistance. ProTaper gold file system had the least fatigue resistance at different radius of curvature in the simulated canal system in the apical and middle portions and S-shaped root canal. CLINICAL SIGNIFICANCE: The selection of file systems in cleaning and shaping protocols is an enigma to the endodontics. This in vitro study explored the selection protocols for the execution of root canal preparation. Heat treatment of nickel-titanium (NiTi) endodontic files had improved the cyclic fatigue résistance significantly enhancing the clinical life of file systems.