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1.
Background: The aim of this study was to evaluate the preventive effect in vitro of experimental gel containing iron and/or fluoride on the erosion of bovine enamel. Methods: To standardize the blocks (n = 80), specimens (4 × 4 mm) were previously selected to measure the initial microhardness. The blocks were randomly allocated into four groups of 20 samples each: C (control, placebo gel); F (fluoride gel, 1.23% NaF); Fe (iron gel, 10 mmol/L FeSO 4) and F + Fe (fluoride + iron gel). The gels were applied and removed after 1 minute. The blocks were then submitted to six alternating remineralization and demineralization cycles. The beverage Coca‐Cola ® (10 minutes, 30 mL) was used for demineralization, and artificial saliva (1 hour) for remineralization. The effect of erosion was measured by wear analysis (profilometry). Data were analysed by ANOVA and the Tukey test for individual comparisons (p <0.05). Results: The mean wear (± SD, μm) was C: 0.94 ± 0.22; F: 0.55 ± 0.12; Fe: 0.49 ± 0.11 and F + Fe: 0.55 ± 0.13. When the experimental gels were used, there was statistically significant reduction in enamel wear in comparison with the control (p <0.001). However, the experimental gels did not differ significantly among them. Conclusions: The gels containing iron with or without fluoride are capable of interfering with the dissolution dental enamel in the presence of erosive challenge. 相似文献
2.
ObjectiveThis study aimed to compare the effects 0.5% and 1% sodium, amine and stannous fluoride at different pH on enamel erosion in vitro. MethodsBovine enamel samples were submitted to a cyclic de- and remineralisation for 3 days. Each day, the samples were exposed for 120 min to pooled human saliva and subsequently treated with one of the fluoride solutions for 3 min: amine fluoride (AmF, 0.5% and 1% F −), sodium fluoride (NaF, 0.5% and 1% F −), each at pH 3.9 and 7.0, and stannous fluoride (SnF 2, 0.5% and 1% F −), at pH: 3.9. Additionally, two groups were treated with fluoride-free placebo solutions (pH: 3.9 and 7.0) and one group served as control (no fluoridation). Ten specimens each group were inserted in a so-called artificial mouth and eroded six times daily with hydrochloric acid (pH 2.6) for 90 s each intermitted by exposure to artificial saliva (1 h). After 3 days, enamel loss was analyzed profilometrically and evaluated statistically by ANOVA. ResultsOnly the acidic 0.5% and 1% SnF 2 and 1% AmF solutions were able to reduce erosive enamel loss significantly, while all other solutions and placebos did not differ significantly from the control. Between the acidic SnF 2 and the 1% AmF solutions no significant differences could be detected. ConclusionAt the same concentrations, acidic SnF 2 and AmF may be more effective than NaF to protect enamel against erosion. 相似文献
3.
The aim of this study was to compare the caries-preventive effect of a stabilized stannous fluoride/sodium fluoride dentifrice containing sodium hexametaphosphate with those of a regular, solely sodium fluoride-containing and amine fluoride-containing dentifrice on pre-demineralized bovine enamel specimens using a pH-cycling model. Bovine enamel specimens with two artificial lesions each were prepared. Baseline mineral loss of both lesions was analyzed using transversal microradiography (TMR). Eighty-five specimens with a mean (SD) baseline mineral loss of 3393 (683) vol% × µm were selected and randomly allocated to five groups ( n = 13/15). Treatments during pH-cycling (28 days and 2 × 20 min demineralization/day) were: brushing twice daily with slurries of AmF (1400 ppm F ?), NaF (1450 ppm F ?), SnF 2/NaF (1100 ppm F ?/350 ppm F ?), and fluoride-free (FF) dentifrices or they were immersed in distilled water and remained unbrushed (NB). Subsequently, from each specimen one lesion was covered with acid-resistant varnish, while the remaining lesion was demineralized for another 14 days. Differences in integrated mineral loss (?? Z) were calculated between values before and after pH-cycling (?? Z E1) as well as before pH-cycling and after second demineralization (?? Z E2) using TMR. Treatments AmF and NaF induced a significantly higher mineral gain (?? Z E1/?? Z E2) compared to treatments FF and NB ( p < 0.05; ANOVA test). Except for treatments AmF and NaF no significant differences in mineral loss between before and after pH-cycling could be observed ( p < 0.05; t test) [?? Z E1: AmF:1563 (767); NaF:1222 (1246); SnF 2/NaF:258 (1259); FF:?52 (1223); NB:?151 (834)]. Both dentifrices with either AmF or NaF promoted remineralization, whereas SnF 2/NaF dentifrice did not promote remineralization in a biofilm-free pH-cycling model. 相似文献
4.
ObjectivesSn 2+ has promising erosion-inhibiting properties in solutions, but little is known about respective effects in toothpastes. In addition, biopolymers might have protecting potential. Aim of this study was to investigate the effects of Sn 2+ in toothpastes and of a biopolymer (chitosan) added to a Sn 2+ formulation on erosion/abrasion. MethodsEnamel samples were subjected to cyclic erosion procedures (10 days; 0.50% citric acid, pH 2.5; 6× 2 min/day), and brushing (2× 15 s/day, load 200 g) during immersion in slurries (2 min). The toothpastes were NaF formulations (NaF/1, NaF/2, NaF/3) and Sn 2+ formulations (NaF/SnCl 2, AmF/SnF 2, AmF/NaF/SnCl 2) and AmF/NaF/SnCl 2 + 0.5% chitosan.Declared concentrations of active ingredients in toothpastes were 1400–1450 μg/g F − and 3280–3500 μg/g Sn 2+. Negative controls were erosion only and placebo, positive control was a SnF 2 gel. Tissue loss was quantified profilometrically, Sn on enamel surfaces was measured by energy dispersive X-ray spectroscopy. ResultsLoss values (μm) for erosion only and placebo were 14.4 ± 4.5 and 20.2 ± 3.8, respectively, and 4.6 ± 1.9 for the positive control ( p ≤ 0.001 each compared to erosion only). The other loss values were: NaF/1 16.5 ± 3.0, NaF/2 14.0 ± 2.7, NaF/3 12.6 ± 3.9, NaF/SnCl 2 14.7 ± 5.1, AmF/SnF 2 13.5 ± 4.8, AmF/NaF/SnCl 2 12.4 ± 4.2, AmF/NaF/SnCl 2 + chitosan 6.6 ± 3.5 (except NaF/1 all p ≤ 0.01 compared to placebo). AmF/NaF/SnCl 2/chitosan was more effective than all other toothpastes ( p ≤ 0.01 each). Sn on the enamel surface ranged between 1.3 ± 0.3 and 2.8 ± 0.04 wt.% with no obvious relationship with efficacy. ConclusionsThe NaF and Sn 2+ toothpastes without chitosan exhibited similar anti-erosion and abrasion-prevention effects. The experimental Sn 2+ formulation with chitosan revealed promising results similar to those of the positive control. Clinical significanceNaF toothpastes offer a degree of protection against erosion/abrasion, which is likely sufficient for most subjects with average acid exposures. For patients with initial erosive lesions, however, more effective toothpaste is desirable. The combination of Sn 2+ and a biopolymer appears promising in this context. 相似文献
5.
International Journal of Paediatric Dentistry 2011 Background. Caries in children younger than 72 months is called early childhood caries (ECC). Sixty‐six per cent of Chinese children younger than 5 years old have dental decay, and about 97% of them are untreated. Aims. This in vitro study was conducted to evaluate the remineralization effects of the casein phosphopeptide‐amorphous calcium phosphate (CPP‐ACP) crème on the artificial early enamel lesions of the primary teeth and to assess its caries‐prevention efficiency. Design. Enamel specimens with artificial early lesions were produced and were then randomly divided into Group A: distilled and deionized water, DDW, as negative control; Group B: CPP‐ACP crème, test group; Group C: 500 ppm NaF solution, as positive control. The enamel surface microhardness (SMH) was measured before, after demineralization, and 30 days after remineralization. The results were analysed with the SPSS 13.0 software package. The enamel specimens were analysed by the scanning electron microscope. Results. The CPP‐ACP crème increased SMH of the eroded enamel significantly more than 500 ppm NaF solution did. The morphology of the enamel was different in each group. Conclusions. The CPP‐ACP crème is effective in remineralizing early enamel lesions of the primary teeth, a little more effective than 500 ppm NaF and can be used for the prevention of ECC. 相似文献
6.
ObjectivesTo investigate the effect of a single application of highly concentrated SnF 2 and NaF solutions and a NaF/CaF 2 varnish on human enamel subjected to hydrochloric acid erosion and tooth brush abrasion. MethodsForty enamel samples were prepared from human third molars and NaF (9500 ppm, pH 8.0), SnF 2 (9500 ppm, pH 2.6) solutions; Bifluorid10 ® varnish (42,500 ppm, NaF 5%, CaF 2 5%) and deionized water (control) was applied to the enamel. Following this three, six and nine cycles of erosion [1 cycle = erosion (0.01 M HCl, pH 2.2, 2 min) + artificial saliva (1 h, pH 7.0)] and erosion-abrasion [1 cycle = erosion (0.01 M HCl, pH 2.2, 2 min) + artificial saliva (1 h, pH 7.0) + abrasion (120 linear strokes in artificial saliva from Tepe medium soft brushes 200 g loading)] were carried out. The fluoride treated enamel was analysed using Knoop microhardness, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). ResultsFor erosion alone, there was significantly less microhardness reduction in the Bifluorid10 ® group after three and six cycles of erosion ( P < 0.05), however no other groups showed statistically different hardness ( P > 0.05). The EDS analysis showed that only the Bifluorid10 ® group had any detectable fluorine following erosion and erosion-abrasion (0.1 wt.% and 0.2 wt.% fluorine respectively). The surface fluorine was found to have been removed after erosion and erosion-abrasion for all other surface treatments. Although precipitates were observed after application of the surface treatments, following erosion-abrasion, no visible surface effects from any fluoride preparation remained. ConclusionsEnamel surface precipitates from application NaF, SnF 2 solutions appear to not be able to provide protection against gastric erosion and tooth brush abrasion. The NaF/CaF 2 varnish provided limited protection against erosion but the role for such varnishes in gastric erosion and tooth brush abrasion remains uncertain. 相似文献
7.
International Journal of Paediatric Dentistry 2011; 22: 11–16 Objective. Previous in vitro study has shown that TiF 4 varnish might reduce enamel erosion. No data regarding the effect of this experimental varnish on enamel erosion plus abrasion, however, are available so far. Thus, this in vitro study aimed to analyse the effect of TiF 4 compared with NaF varnishes and solutions, to protect against enamel erosion with or without abrasion. Methods. Enamel specimens were pre‐treated with experimental‐TiF 4 (2.45% F), experimental‐NaF (2.45% F), NaF‐Duraphat (2.26% F), and placebo varnishes; NaF (2.26% F) and TiF 4 (2.45% F) solutions. Controls remained untreated. The erosive challenge was performed using a soft drink (pH 2.6) 4 × 90 s/day (ERO) and the toothbrushing abrasion (ERO+ABR) 2 × 10 s/day, for 5 days. Between the challenges, the specimens were exposed to artificial saliva. Enamel loss was measured profilometrically (μm). Results. Kruskal–Wallis/Dunn tests showed that all fluoridated varnishes (TiF 4–ERO:0.53 ± 0.20, ERO+ABR:0.65 ± 0.19/NaF‐ERO:0.94 ± 0.18, ERO+ABR:1.74 ± 0.37/Duraphat‐ERO:1.00 ± 0.37, ERO+ABR:1.72 ± 0.58) were able to significantly reduce enamel loss when compared with placebo varnish (ERO:3.45 ± 0.41/ERO+ABR:3.20 ± 0.66) ( P < 0.0001). Placebo varnish, control (ERO:2.68 ± 0.53/ERO+ABR:3.01 ± 0.34), and fluoridated (NaF‐ERO:2.84 ± 0.09/ERO+ABR:2.40 ± 0.21/TiF 4‐ERO:3.55 ± 0.59/ERO+ABR:4.10 ± 0.38) solutions did not significantly differ from each other. Conclusion. Based on the results, it can be concluded that the TiF 4 varnish seems to be a promising treatment to reduce enamel loss under mild erosive and abrasive conditions in vitro. 相似文献
8.
Objective This in vitro study assessed the anti-erosive effect of experimental mouthrinses containing TiF 4 and NaF on dentin erosive loss. Material and Methods Bovine dentin specimens were randomly allocated into the groups (n=15): 1) SnCl 2/NaF/AmF (Erosion Protection ®/GABA, pH 4.5, positive control); 2) experimental solution with 0.0815% TiF 4 (pH 2.5); 3) 0.105% NaF (pH 4.5); 4) 0.042% NaF+0.049% TiF 4 (pH 4.4); 5) 0.063% NaF+0.036% TiF 4 (pH 4.5); 6) no treatment (negative control). Each specimen was cyclically demineralized (Sprite Zero, pH 2.6, 4x90 s/day) and exposed to artificial saliva between the erosive challenges for 7 days. The treatment with the fluoride solutions was done 2x60 s/day, immediately after the first and the last erosive challenges of the day. Dentin erosive loss was measured by profilometry (μm). The data were analyzed using Kruskal Wallis/Dunn tests (p<0.05). Results Mouthrinses containing TiF 4 or Sn/F were able to show some protective effect against dentin erosive loss compared to negative control. The best anti-erosive effect was found for experimental solution containing 0.0815% TiF 4 (100% reduction in dentin loss), followed by 0.042% NaF+0.049% TiF 4 (58.3%), SnCl 2/NaF/AmF (52%) and 0.063% NaF+0.036% TiF 4 (40%). NaF solution (13.3%) did not significantly differ from control. Conclusion The daily application of experimental mouthrinse containing TiF 4 and NaF has the ability to reduce dentin erosion, as well as Erosion Protection ® and TiF 4 alone. 相似文献
9.
Abstract Objectives. This in vitro study aimed to analyze the effect of TiF 4 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/CaF 2-Duofluorid (5.63% F), experimental-NaF (2.45% F), experimental-TiF 4 (2.45% F) and placebo varnishes; NaF (2.26% F) and TiF 4 (2.45% F) solutions. Controls remained untreated. The erosive pH cycling was performed using a soft drink (pH 2.6) 4 × 90 s/day and the toothbrushing-abrasion 2 × 10 s/day, in vitro for 5 days. Between the challenges, the specimens were exposed to artificial saliva. Dentin tissue loss was measured profilometrically (μm). 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; TiF 4, 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; TiF 4, 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. 相似文献
10.
Objectives It is well known that Sn 2+ is a notable anti-erosive agent. There are indications that biopolymers such as chitosan can enhance the effect of Sn 2+, at least in vitro. However, little information exists about their anti-erosive/anti-abrasive in situ effects. In the present in situ study, the efficacy of Sn 2+-containing toothpastes in the presence or absence of chitosan was tested. Methods Ten subjects participated in the randomised crossover study, wearing mandibular appliances with human enamel specimens. Specimens were extraorally demineralised (7 days, 0.5 % citric acid, pH?2.6; 6?×?2 min/day) and intraorally exposed to toothpaste suspensions (2?×?2 min/day). Within the suspension immersion time, one half of the specimens were additionally brushed intraorally with a powered toothbrush (5 s, 2.5 N). Tested preparations were a placebo toothpaste (negative control), two experimental toothpastes (F/Sn = 1,400 ppm?F ?, 3,500 ppm Sn 2+; F/Sn/chitosan = 1,400 ppm?F ?, 3,500 ppm Sn 2+, 0.5 % chitosan) and an SnF 2-containing gel (positive control, GelKam = 3,000 ppm Sn 2+, 1,000 ppm?F ?). Substance loss was quantified profilometrically (μm). Results In the placebo group, tissue loss was 11.2?±?4.6 (immersion in suspension) and 17.7?±?4.7 (immersion in suspension?+?brushing). Immersion in each Sn 2+-containing suspension significantly reduced tissue loss ( p?≤?0.01); after immersion in suspension?+?brushing, only the treatments with GelKam (5.4?±?5.5) and with F/Sn/chitosan (9.6?±?5.6) significantly reduced loss [both p?≤?0.05 compared to placebo; F/Sn 12.8?±?6.4 (not significant)] Conclusion Chitosan enhanced the efficacy of the Sn 2+-containing toothpaste as an anti-erosive/anti-abrasive agent. Clinical relevance The use of Sn 2+- and chitosan-containing toothpaste is a good option for symptomatic therapy in patients with regular acid impacts. 相似文献
11.
Objective. The aim of this study was to compare the protective effect of TiF 4, SnF 2, and NaF treatment on the development of erosion-like lesions in pellicle-covered human enamel. Material and Methods. Twelve human molars were each divided into 5 specimens, 4 of which were immersed in saliva for 2 h. Three pellicle-covered specimens from each tooth were treated with a TiF 4, SnF 2, or NaF solution (all 0.5 M F) for 2 min. Control specimens, one with and one without pellicle, were included. Immersion in acid (0.01 M HCl) was carried out stepwise (2+2+2+2 min). The etching depths (in µm) were measured using white light interferometry. Results. Compared with the control with pellicle, TiF 4 reduced enamel loss by 100% after 2 min and by 24% after 8 min of acid exposure. The corresponding values for SnF 2 were 45% and 14%. NaF provided no significant protection of the surface. The pellicle-covered specimens showed reduced lesion depths after 6 and 8 min compared to the controls without pellicle. Conclusions. TiF 4 gave the best protection against acid attack. SnF 2 provided significant protection only after 2 min of acid exposure, while NaF had no significant protective effect. 相似文献
12.
ObjectiveThe purpose of this in situ study was to evaluate different dentifrices on enamel after bleaching under normal and hyposalivatory conditions. Materials and methodsTwenty-four participants were assigned of which 12 had normal and 12 had low salivary flow. The study was conducted in 6 in situ experimental phases of 24 h duration: placebo, NaF, SnF2, F/Sn/Chitosan, F/Arginine, and F/Bioactive Glass. The specimens were previously bleached in vitro. Microhardness (SMH), roughness (Ra), and color analyses (CIELAB and ΔE00) were performed at baseline (T1), after bleaching (T2) and after in situ phase (T3). Scanning electron microscopy (SEM) and the elemental levels (wt%) of Ca, P, and Na and the proportion between Ca and P were determined using an energy-dispersive X-ray spectrometer (EDS) in T3. The SMH and Ra were analyzed by mixed models for repeated measures and Tukey Kramer. The color and Na% were analyzed by split-plot ANOVA and Tukey test. The EDS were analyzed by Mann’s Whitney nonparametric, Friedman, and Nemenyi tests (p<0.05). ResultsThe dentifrices placebo and NaF in the low flow presented lower SMH and higher Ra in T3 and lower Ca% compared to the same dentifrices in normal flow. For normal flow, SnF2 resulted in greater SMH. For low flow, SnF2, F/Sn/Chitosan, and F/Bioactive Glass resulted in higher SMH in T3 and did not differ from T1. F/Bioactive Glass showed lower Ra among the dentifrices evaluated for both salivary flows, whereas SnF2 showed the highest. F/Bioactive Glass showed a statistically significant difference from placebo for Ca%, P%, Na%. For ΔE*ab and ΔE00 (T1×T3), no differences were found for the dentifrices and salivary flows. ConclusionThe low salivary flow had less capacity for remineralization of bleached enamel compared to normal flow. Overall, the dentifrice with bioactive glass had the best performance in bleached enamel under low and normal salivary flow condition. Clinical relevanceIt is recommended to use a bioactive glass-based dentifrice after bleaching to promote tooth enamel recovery for patients with or without impaired salivary flow. 相似文献
13.
Fluoride varnishes play an important role in the prevention of dental caries,
promoting the inhibition of demineralization and the increase of
remineralization. Objective This study aimed to analyze the amount of fluoride released into water and
artificial saliva from experimental TiF 4 and NaF varnishes, with
different concentrations, for 12 h. Material and Methods Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of
deionized water and artificial saliva in polystyrene bottles. The acrylic blocks
were divided in seven groups (n=10): 1.55% TiF 4 varnish (0.95% F, pH
1.0); 3.10% TiF 4 varnish (1.90% F, pH 1.0); 3.10% and 4% TiF 4
varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF
varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no
treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h
of exposure. The analysis was performed using an ion-specific electrode coupled to
a potentiometer. Two-way ANOVA and Bonferroni''s test were applied for the
statistical analysis (p<0.05). Results TiF 4 varnishes released larger amounts of fluoride than NaF varnishes
during the first 1/2 h, regardless of their concentration; 4% TiF 4
varnish released more fluoride than NaF varnishes for the first 6 h. The peak of
fluoride release occurred at 3 h. There was a better dose-response relationship
among the varnishes exposed to water than to artificial saliva. Conclusions The 3.10% and 4% TiF 4 -based varnishes have greater ability to release
fluoride into water and artificial saliva compared to NaF varnish; however, more
studies must be conducted to elucidate the mechanism of action of TiF 4
varnish on tooth surface. 相似文献
14.
Background: Matrix metalloproteinase (MMP) inhibitors reduce dentine erosion. This in vitro study evaluated the effect of the supplementation of soft drinks with green tea extract, a natural inhibitor of MMPs, on their erosive potential against dentine. Methods: For each drink tested (Coca‐Cola?, Kuat? guarana, Sprite? and light Coca‐Cola?), 40 dentine specimens were divided into two subgroups differing with respect to supplementation with green tea extract at 1.2% (OM24 ®, 100% Camellia sinensis leaf extract, containing 30 ± 3% of catechin; Omnimedica, Switzerland) or not (control). Specimens were subjected to four pH cycles, alternating de‐ and remineralization in one day. For each cycle, samples were immersed in pure or supplemented drink (10 minutes, 30 mL per block) and in artificial saliva (60 minutes, 30 mL per block) at 37 °C, under agitation. Dentine alterations were determined by profilometry (μm). Data were analysed by two‐way ANOVA and Bonferroni’s test (p < 0.05). Results: A significant difference was observed among the drinks tested with Sprite? leading to the highest surface loss and light Coca‐Cola? to the lowest. Supplementation with green tea extract reduced the surface loss by 15% to 40% but the difference was significant for Coca‐Cola? only. Conclusions: Supplementation of soft drinks with green tea extract might be a viable alternative to reduce their erosive potential against dentine. 相似文献
15.
The aim of this study was to evaluate the effect of professional flossing with NaF and SnF 2 gels on caries development on approximal tooth surfaces. Two-hundred-and-eighty 13-year-old schoolchildren were divided into 3 groups: (1) NaF ( n = 97), (2) SnF 2 ( n = 85), and (3) placebo gel group ( n = 98). The investigation was carried out double-blind. The children were treated 4 times a year for 3 years with 1% NaF gel, 1% SnF 2 gel, or placebo gel. The treatment was carried out by dental nurses and the time required per visit was approximately 10 min. After 3 years, the mean approximal caries increment, including initial caries lesions, was 2.8 in the NaF, 2.4 in the SnF 2, and 4.0 in the placebo gel group ( P < 0.05 for SnF 2 vs placebo); a reduction compared to the placebo of 30% and 39% in the NaF and SnF 2 groups, respectively. Thus, professional flossing with NaF or SnF 2 gel carried out 4 times a year may be considered as an interesting caries-preventing method for large-scale application in schoolchildren. 相似文献
16.
The objective of this study was to evaluate the effect of the addition of stannous fluoride (SnF 2) and sodium fluoride (NaF) to luting cements on the retention of provisional crowns. Provisional crowns were fabricated using methyl methacrylate and bis-acryl composite resin for 32 chamfer prepared molars. For control group A, crowns were cemented with Freegenol and RelyX Temp NE non-eugenol cements. For test group B, crowns were cemented using the above cements with the addition of SnF 2. For test group C, crowns were cemented using the above cements with the addition of NaF. The specimens were thermocycled and retention test was conducted after 7 days. The addition of SnF 2 significantly increased the retentive strength of both the cements in the range of 27–48 %, whereas addition of NaF decreased the retentive strength of both the cements in the range of 14–23 %. SnF 2 can be mixed with non-eugenol luting cements to improve the retention of both methyl methacrylate and bis-acryl composite crowns. The different effects of NaF and SnF 2 on retention indicate that it may be useful to have two different types of provisional luting cements for short-term and long-term cementation, as appropriate. 相似文献
17.
ObjectivesVarious 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. MethodsBovine enamel blocks were subjected to short-term acidic exposure by immersion in citric acid 0.05 M (pH 2.5) for 15 s, 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 2 h. Enamel remineralization was measured by superficial hardness test (% superficial hardness change). The data were tested using ANOVA and Tukey's test ( p < 0.05). ResultsAll 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). ConclusionsBesides the variety of artificial saliva for erosion in vitro protocols, all the formulations tested were able to partially remineralize initial erosive lesions. 相似文献
18.
A conventional (Minimax), two single-particle high-Cu (Summalloy and Aristaloy CR), and two dispersed-phase (Cluster and Phasealloy) amalgam alloys were each admixed with 0.5 wt% of CuF 2, InF 3, SnF 2, and CaF 2, and evaluated for F −, Cu, and Sn release, as well as for corrosion resistance, microstructure, and compressive strength. Over a 43-week interval, only Cluster revealed somewhat of a sustained F − release in artificial saliva. A ranking for F − release was Cluster (highest), Summalloy, Phasealloy, Minimax, and Aristaloy CR. The effectiveness of the F − compounds in releasing F − followed CuF 2 (highest), SnF 2, InF 3 (1.0%), InF 3, and CaF 2. Amalgams with admixed CuF 2 released both the most Cu and increased Sn. For three amalgams, CaF 2 admixtures also increased the Cu release. Constant-potential coulometry distinguished among the different fluoride amalgams. Only Minimax revealed a significant reduction in compressive strength with two admixtures. Microstructural analysis revealed an increased pore distribution around the Ag-Cu dispersed particles, and it was assumed that the F − particles were contained within the pores, since SEM, EDS with a low element detector, and ESCA were all unable to detect the F − particles. 相似文献
19.
Abstract Objective. Application of SnCl 2/AmF/NaF containing mouth rinse showed good protection against erosion. The aim of the study was to evaluate if this is due to the amount of KOH-soluble fluoride (KOHsF) formed or its resistance under erosive conditions. Methods. One hundred and fifty bovine enamel samples were allocated to five groups (n = 30) and were once eroded in 0.05 mol/l citric acid (5 min). Samples were stored in artificial saliva for 4 days. Samples of two groups (erosive-SnCl 2 + erosive-NaF) were eroded 6 × for 5 min. The remaining samples were stored in aqua dest deionised water. Each day the samples were treated twice for 2 min with 1 ml SnCl 2/AmF/NaF-solution (erosive-SnCl 2;neutral-SnCl 2/AmF/NaF) or NaF-solution (erosive-NaF;neutral-NaF). The fifth group remained untreated (control). On day 5, 10 samples of each group were used for determination of KOHsF (series 1). The remaining samples were again eroded (erosive-SnCl 2 + erosive-NaF) or stored in artificial saliva (neutral-SnCl 2 + neutral-NaF). KOHsF of another 10 samples of each group was measured (series 2). The last 10 samples of each group were also treated as described above and the amount of KOHsF was measured (series 3). Results. In each series 1–3 KOHsF in group erosive-SnCl 2/AmF/NaF were significantly higher. No significant loss of KOHsF between the series 1–3 was observed (except for control). Conclusion. SnCl 2/AmF/NaF containing mouth rinse revealed a better formation of KOH-soluble fluoride as the NaF-solution, although the applied fluoride compound has no influence on the stability of the KOHsF under erosive conditions, leading to the conclusion that the resistance of KOHsF is not responsible for the difference in the protection against dental erosion. 相似文献
20.
The addition of tin to mouth rinses is, at least in vitro, a promising strategy for symptomatic therapy of dental erosion.
The aim of this study was to evaluate the in situ efficacy of an experimental tin-containing fluoride solution on erosive
tissue loss in human enamel and dentine. The study was a three-cell (7 days each) crossover design involving eight healthy
participants. Samples were mounted on buccal shields of mandibular mouth appliances, which were worn for 24 h except during
meals and drinks. Specimens were demineralised extraorally with 0.05 M citric acid (pH 2.3) for 6 × 5 min daily and were treated
with test solutions intraorally once per day for 30 s after the first demineralisation. Three solutions were used: placebo
(negative control), a commercially available tin- and fluoride-containing (SnF 2) mouth rinse (positive control, 409 ppm Sn 2+, 250 ppm F −, pH 4.2) and an experimental solution (pH 4.5) containing 1,900 ppm Sn 2+ (SnCl 2) and 1,000 ppm F − (AmF/NaF). Tissue loss (micrometre) was determined profilometrically. In enamel, tissue loss was 54.8 ± 8.6 in the placebo,
24.5 ± 14.4 in the positive control and 9.7 ± 4.1 in the experimental solution group. The respective values for dentine were
48.5 ± 13.0 in the placebo, 32.8 ± 9.6 in the positive control and 26.2 ± 6.7 in the experimental solution group. The experimental
solution was notably effective for enamel but was less effective for dentine. The positive control solution was less effective
than the experimental solution; its effects for enamel and dentine were similar. 相似文献
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