Non-isothermal kinetic applied to thermal decomposition of commercial alkyd varnish

Samples of commercial alkyd resin varnish were spread in a film form on slides, dried at room temperature and exposed to solar radiation from one day up to seven months.Thermogravimetric measurements have been done. Based on the TG data, the Flynn-Wall isoconversional method was applied. The activation energy varied between 176-154 kJ mol(-1) and logA was between 15.5-12.9 min(-1) for A, B and C samples at 95% confidence level.

Effect of fluoridated varnish and silver diamine fluoride solution on enamel demineralization: pH-cycling study

Objective: In the present investigation, the anticariogenic effect of fluoride released by two products commonly applied in infants was evaluated. Methods: Bovine sound enamel blocks were randomly allocated to each one of the treatment groups: control (C), varnish (V) and diamine silver fluoride solution (D). The blocks were submitted to pH cycles in an oven at 37°C. Next, surface and cross-sectional microhardness were assessed to calculate the percentage loss of surface microhardness (%SML) and the mineral loss (ΔZ). The fluoride present in enamel was also determined. Results: F/Px10 -3 (ANOVA, p<0.05) in the 1 st layer of enamel before pH-cycling were (C, V and D): 1.61 a; 21.59 b and 3.98 c. The %SMH (Kruskal-Wallis, p<0.05) were: -64.0 a, -45.2 b and -53.1 c. %ΔZ values (ANOVA, p<0.05) were: -18.7 a, -7.7 b and -17.3 a. Conclusion: The data suggested that the fluoride released by varnish showed greater interaction with sound enamel and provided less mineral loss when compared with silver diamine solution.

Comparison of the caries-preventive effect of a glass ionomer sealant and fluoride varnish on newly erupted first permanent molars of children with and without dental caries experience

Purpose: This longitudinal clinic study evaluated the effect of a glass ionomer sealant (GIS) and a fluoride varnish (FV) in the prevention of dental decay on newly erupted permanent molars of children with and without caries experience. Materials and methods: Eighty children, aged 6-8 years, with all four newly erupted first permanent molars, were divided into two groups. Group 1 consisted of 53 children without caries experience and group 2 consisted of 27 children with dental caries experience. Permanent molars of the right side were sealed with GIS and the fluoride varnish was applied on the other two permanent first molars. Evaluation of GIS retention and the effectiveness of both materials in the prevention of dental caries were performed after 6, 12 and 18 months. Results: After 18 months, of the 299 teeth, 271 (91%) showed no caries lesions and 28 presented caries lesions (9%). Teeth sealed with GIS had more carious lesions (15) than teeth with fluoride varnish (13). Most of the teeth (70%) that presented carious lesions were in group 2. Of the 138 sealed teeth, only one showed GIS to be totally present, 95 were partially present and 42 teeth were absent. Conclusion: The caries-preventive effect was very similar between both treatments. The presence of dental caries prevailed in the children with caries experience. © 2013 Informa Healthcare.

Effect of fluoride varnish supplemented with sodium trimetaphosphate on enamel erosion and abrasion: An in situ/ex vivo study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of fluoride varnish supplemented with sodium trimetaphosphate on enamel erosion and abrasion

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Control of white spot lesion adjacent to orthodontic bracket with use of fluoride varnish or chlorhexidine gel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of NaF and TiF4 varnish and solution on bovine dentin erosion plus abrasion in vitro

Objectives. This in vitro study aimed to analyze the effect of TiF4 compared to NaF varnishes and solutions, to protect against dentin erosion associated with abrasion. Materials and methods. Bovine dentin specimens were pre-treated with NaF-Duraphat (2.26% F), NaF/CaF2-Duofluorid (5.63% F), experimental-NaF (2.45% F), experimental-TiF4 (2.45% F) and placebo varnishes; NaF (2.26% F) and TiF4 (2.45% F) solutions. Controls remained untreated. The erosive pH cycling was performed using a soft drink (pH 2.6) 4 x 90 s/day and the toothbrushing-abrasion 2 x 10 s/day, in vitro for 5 days. Between the challenges, the specimens were exposed to artificial saliva. Dentin tissue loss was measured profilometrically (mu m). Results. ANOVA/Tukey's test showed that all fluoridated varnishes (Duraphat, 7.5 +/- 1.1; Duofluorid, 6.8 +/- 1.1; NaF, 7.2 +/- 1.9; TiF4, 6.5 +/- 1.0) were able to significantly reduce dentin tissue loss (40.7% reduction compared to control) when compared to placebo varnish (11.2 +/- 1.3), control (11.8 +/- 1.7) and fluoridated (NaF, 9.9 +/- 1.8; TiF4, 10.3 +/- 2.1) solutions (p < 0.0001), which in turn did not significantly differ from each other. Conclusion. All fluoridated varnishes, but not the solutions, had a similar performance and a good potential to reduce dentin tissue loss under mild erosive and abrasive conditions in vitro. Risk patients for erosion and abrasion, especially those with exposed dentin, should benefit from this clinical preventive measure. Further research has to confirm this promising result in the clinical situation.

In situ effect of sodium fluoride or titanium tetrafluoride varnish and solution on carious demineralization of enamel

This study evaluated the effect of titanium tetrafluoride (TiF4) formulations on enamel carious demineralization in situ. Thirteen subjects took part in this cross-over, split-mouth, double-blind study performed in three phases of 14 d each. In each subject, two sound and two predemineralized specimens of bovine enamel were worn intra-orally and plaque accumulation was allowed. One sound and one predemineralized specimen in each subject was treated once with sodium fluoride (NaF) varnish or solution (Treatment A); TiF4 varnish or solution (Treatment B); or placebo varnish or no treatment (Treatment C). The initially sound enamel specimens were exposed to severe cariogenic challenge (20% sucrose, eight times daily for 5 min each time), whereas the predemineralized specimens were not. Eleven subjects were able to finish all experimental phases. The enamel alterations were quantified by surface hardness and transversal microradiography. Demineralization of previously sound enamel was reduced by all test formulations except for the NaF solution, while both TiF4 formulations were as effective as NaF varnish. For the predemineralized specimens, enamel surface hardness was increased only by TiF4 formulations, while subsurface mineral remineralization could not be seen in any group. Within the experimental protocol, TiF4 was able to decrease enamel demineralization to a similar degree as NaF varnish under severe cariogenic challenges, while only TiF4 formulations remineralized the enamel surface.

Caries-preventive effectiveness of fluoride varnish as adjunct to oral health promotion and supervised tooth brushing in preschool children: a double-blind randomized controlled trial.

OBJECTIVES To evaluate the effect of biannual fluoride varnish applications in preschool children as an adjunct to school-based oral health promotion and supervised tooth brushing with 1000ppm fluoride toothpaste. METHODS 424 preschool children, 2-5 year of age, from 10 different pre schools in Athens were invited to this double-blind randomized controlled trial and 328 children completed the 2-year programme. All children received oral health education with hygiene instructions twice yearly and attended supervised tooth brushing once daily. The test group was treated with fluoride varnish (0.9% diflurosilane) biannually while the control group had placebo applications. The primary endpoints were caries prevalence and increment; secondary outcomes were gingival health, mutans streptococci growth and salivary buffer capacity. RESULTS The groups were balanced at baseline and no significant differences in caries prevalence or increment were displayed between the groups after 1 and 2 years, respectively. There was a reduced number of new pre-cavitated enamel lesions during the second year of the study (p=0.05) but the decrease was not statistically significant. The secondary endpoints were unaffected by the varnish treatments. CONCLUSIONS Under the present conditions, biannual fluoride varnish applications in preschool children did not show significant caries-preventive benefits when provided as an adjunct to school-based supervised tooth brushing with 1000ppm fluoride toothpaste. CLINICAL SIGNIFICANCE In community based, caries prevention programmes, for high caries risk preschool children, a fluoride varnish may add little to caries prevention, when 1000ppm fluoride toothpaste is used daily.

Die Gesamtorganisation der jüdischen Gemeinden Preußens : kritische Beleuchtung d. Grundprinzipien des Rosin'schen Gesetzentwurfes

Referat ... von M. Lerner

Dr. David Rosin, geboren am 27. Mai 1823, gestorben am 31. December 1894 : ein Nachruf

von David Kaufmann

Prof. Dr. H. Rosin [Illustration] : (Porträt)

Scan von Monochrom-Mikroform

Papers on paint and varnish and the materials used in their manufacture,

"In the present work the author brings up to date the series of technical papers which he has prepared as circulars of the Educational bureau of the Paint and varnish manufacturers association of the United States, since January 1919."--Pref.