Effect of a Titanium Tetrafluoride Varnish in the Prevention and Treatment of Carious Lesions in the Permanent Teeth of Children Living in a Fluoridated Region: Protocol for a Randomized Controlled Trial.

BACKGROUND: Titanium tetrafluoride (TiF4) has regained interest due to new formulations that have been shown to be more effective against tooth demineralization than sodium fluoride (NaF) formulations in vitro and in situ. OBJECTIVE: The aim of this study is to evaluate the effect of two types of varnishes (4% TiF4 and a commercial 5% NaF) on the prevention of carious lesions and the treatment of noncavitated enamel carious lesions in the permanent teeth of children living in a fluoridated area. METHODS: This randomized, controlled, parallel and single-blind clinical trial involves 63 children, 6-7 years old, living in Bauru, São Paulo, Brazil. Children were selected according to their caries activity (ie, presence of at least 1 tooth with a Nyvad score of 1) and randomly divided into the following treatment categories: 4% TiF4 varnish (2.45 % F-, pH 1, FGM); 5% NaF varnish (2.26% F-, pH 5, Duraphat, Colgate) and control (placebo varnish, pH 5, FGM). The varnishes will be applied on all permanent teeth, once a week for 4 weeks and they will be reapplied only once 6 and 12 months after the study begins. Two calibrated examiners will carry out the clinical examination (International Caries Detection and Assessment System [ICDAS] and Nyvad indexes, kappa>.8) at baseline, before the first application, after the 1st, 6th, 12th, and 18th month of the study begins. Furthermore, quantitative fluorescence changes will be measured using Quantitative Light-Induced Fluorescence (QLF). The degree of patient satisfaction with the treatment will also be computed. The data will undergo statistical analysis (P<.05). RESULTS: This ongoing study is funded by funding agencies from Brazil (São Paulo Research Foundation, FAPESP-015/14149-1, and National Council for Scientific and Technological Development, CNPq-401313/2016-6). We expect to confirm the efficacy of TiF4 on the prevention and treatment of carious lesions by comparing it to NaF varnish. The subjects are under 1 month evaluation and the dropout was about 8%. No differences between the treatments have been detected at the first month so far (P>.05). CONCLUSIONS: If our hypothesis is confirmed, TiF4 varnish can be marketed and applied at the individual level and used in community programs to control dental caries. TRIAL REGISTRATION: Brazilian Clinical Trials Registry: RBR-5VWJ4Y; http://www.ensaiosclinicos.gov.br/rg/?q=RBR-5VWJ4Y (Archived by WebCite at http://www.webcitation.org/6wUurEnm7).

Building, testing and validating a set of home-made von Frey filaments: a precise, accurate and cost effective alternative for nociception assessment.

BACKGROUND: A von Frey filament (vFF) is a type of aesthesiometer usually made of nylon perpendicularly held in a base. It can be used in paw withdrawal pain threshold assessment, one of the most popular tests for pain evaluation using animal models. For this test, a set of filaments, each able to exert a different force, is applied to the animal paw, from the weakest to the strongest, until the paw is withdrawn. NEW METHOD: We made 20 low cost vFF using nylon filaments of different lengths and constant diameter glued perpendicularly to the ends of popsicle sticks. They were calibrated using a laboratory balance scale. Building and calibrating took around 4h and confirmed the theoretical prediction that the force exerted is inversely proportional to the length and directly proportional to the width of the filament. RESULTS: The calibration showed that they were precise and accurate. We analyzed the paw withdrawal threshold assessed with the set of home-made vFF and with a high quality commercial set of 5 monofilaments vFF (Stoelting, Wood Dale, USA) in two groups (n=5) of healthy mice. COMPARISON WITH EXISTING METHODS: The home-made vFF precisely and accurately measured the hind paw withdrawal threshold (20.3±0.9 g). The commercial vFF have different diameters while our set has the same diameter avoiding the problem of lower sensitivity to larger diameter filaments. CONCLUSION: Building a set of vFF is easy, cost effective, and depending on the kind of tests, can increase precision and accuracy of animal nociception evaluation.

In vitro assessment of artificial saliva formulations on initial enamel erosion remineralization.

OBJECTIVES: Various formulations of artificial saliva are present in the literature and little guidance is available on the standardization of type of saliva for use in in vitro protocols for erosive studies. The aim of this study was to evaluate the remineralizing capacity of different formulations of artificial saliva on initial enamel erosive lesion. METHODS: Bovine enamel blocks were subjected to short-term acidic exposure by immersion in citric acid 0.05 M (pH 2.5) for 15s, resulting in surface softening without tissue loss. Then 90 selected eroded enamel blocks were randomly and equally divided into 6 groups according to saliva formulation (n=15): Saliva 1 (contain mucin); Saliva 2 (Saliva 1 without mucin); Saliva 3; Saliva 4; Saliva 5 (contain sodium carboxymethyl cellulose) and control (C) (deionized water). After demineralization enamel blocks were subjected to remineralization by immersion in the saliva's formulations for 2h. Enamel remineralization was measured by superficial hardness test (% superficial hardness change). The data were tested using ANOVA and Tukey's test (p<0.05). RESULTS: All the tested formulations of artificial saliva resulted in significantly higher enamel remineralization compared to control (p<0.001). Saliva 3 showed higher percentage of enamel remineralization than Saliva 5 (p<0.05). CONCLUSIONS: Besides the variety of artificial saliva for erosion in vitro protocols, all the formulations tested were able to partially remineralize initial erosive lesions.