TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

Objective

This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h) with a 4% TiF₄ varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva) for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM). Enamel and dentin data were analyzed using ANOVA/Tukey’s and Kruskal-Wallis/Dunn tests, respectively (p<0.05).

Results

The TiF₄ (mean±s.d: 1.5±1.1 µm) and NaF (2.1±1.7 µm) varnishes significantly reduced enamel wear progression compared to the placebo varnish (3.9±1.1 µm) and control (4.5±0.9 µm). The same differences were found for dentin in the presence and absence of the DOM, respectively: TiF₄ (average: 0.97/1.87 µm), NaF (1.03/2.13 µm), placebo varnish (3.53/4.47 µm) and control (3.53/4.36 µm).

Conclusion

The TiF₄ and NaF varnishes were equally effective in reducing the progression of tooth erosion in vitro.     

Effect of natural gel product on bovine dentin erosion in vitro

Objective

To evaluate the efficacy of Neem (Azadirachta indica) experimental gel for the prevention of erosive wear on bovine dentin, in vitro.

Material and Methods

One hundred dentin blocks were allocated into 5 experimental groups (20 samples each): C (control group, without gel); CG (control group, only base gel); F (fluoride gel, 1.23% NaF; pH 4.1, Dentsply; Brazil); N (Neem gel, 10% neem extract; pH 4.1, manipulation); NF (Neem+fluoride gel, 10% Neem extract and 1.23% NaF; pH 4.1, manipulation). The blocks were stored in artificial saliva for 24 hours. After this, they were submitted to six alternating re- and demineralization cycles. The blocks were analyzed for wear (profilometry). The results were submitted to statistical analysis by ANOVA and Tukey tests (P<0.05).

Results

The mean wear (±SD, µm) was shown as follows in groups: C (13.09±0.99), CG (10.60±1.99), F (10.90±1.44), N (12.68±1.13) and NF (10.84±1.65). All gels showed some preventive action when compared with control group. However, significant differences were found only between Neem+fluoride gel and fluoride gel.

Conclusion

A single application of a neem-containing fluoride gel reduced dentin erosion, thus it is a possible alternative in reducing dental wear. Further research should investigate the action mechanism and the synergism between them.     

Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

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 TiF₄ 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% TiF₄ varnish (0.95% F, pH 1.0); 3.10% TiF₄ varnish (1.90% F, pH 1.0); 3.10% and 4% TiF₄ 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

TiF₄ varnishes released larger amounts of fluoride than NaF varnishes during the first 1/2 h, regardless of their concentration; 4% TiF₄ 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% TiF₄ -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 TiF₄ varnish on tooth surface.     

Effect of experimental mouthrinses containing the combination of NaF and TiF4 on enamel erosive wear in vitro

Objective

This study analysed the anti-erosive effect of experimental solutions containing TiF₄ and NaF.

Methods

Bovine enamel samples (n = 15) were treated with: (1) commercial solution with SnCl₂/NaF (Erosion Protection^®); (2) experimental solution with 0.0815% TiF₄; (3) 0.105% NaF; (4) 0.042% NaF + 0.049% TiF₄; (5) 0.063% NaF + 0.036% TiF₄ or (6) control. The samples were submitted to pH cycles and daily fluoride applications for seven days. The enamel wear was measured using a contact profilometer and analysed by ANOVA (p < 0.05).

Results

The best anti-erosive effect was found for experimental solution with 0.0815% TiF₄ (99% reduction in enamel wear), followed by SnCl₂/NaF (78%) and 0.049% TiF₄ + 0.042% NaF solution (41%).

Conclusions

The experimental solution containing a specific combination of TiF₄ + NaF has the ability to partially reduce enamel erosion.     

Iron supplementation reduces the erosive potential of a cola drink on enamel and dentin in situ

Iron has been suggested to reduce the erosive potential of cola drinks in vitro.

Objective

The aim of this study was to evaluate in situ the effect of ferrous sulfate supplementation on the inhibition of the erosion caused by a cola drink.

Material and Methods

Ten adult volunteers participated in a crossover protocol conducted in two phases of 5 days, separated by a washout period of 7 days. In each phase, they wore palatal devices containing two human enamel and two human dentin blocks. The volunteers immersed the devices for 5 min in 150 mL of cola drink (Coca-Cola^TM, pH 2.6), containing ferrous sulfate (10 mmol/L) or not (control), 4 times per day. The effect of ferrous sulfate on the inhibition of erosion was evaluated by profilometry (wear). Data were analyzed by paired t tests (p<0.05).

Results

The mean wear (±se) was significantly reduced in the presence of ferrous sulfate, both for enamel (control: 5.8±1.0 µm; ferrous sulfate: 2.8±0.6 µm) and dentin (control: 4.8±0.8 µm; ferrous sulfate: 1.7±0.7 µm).

Conclusions

The supplementation of cola drinks with ferrous sulfate can be a good alternative for the reduction of their erosive potential. Additional studies should be done to test if lower ferrous sulfate concentrations can also have a protective effect as well as the combination of ferrous sulfate with other ions.     

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

Abstract

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 × 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; 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.     

Resin-based materials to control human dentin permeability under erosive conditions in vitro: A hydraulic conductance,confocal microscopy and FTIR study

ObjectivesTo characterize the behavior of three different polymeric agents before and after an erosive challenge on dentin permeability, to analyze their degradation in both conditions, and to analyze their degree of conversion (DC).MethodsThe permeability of human dentin disks (1.0 ± 0.2 mm) was measured with smear layer, after its removal, after treatment (LpTreat) with Gluma Desensitizer, PRG Barrier Coat (PBC) or Icon infiltrant (n = 11/group) and after exposure to citric acid (LpEro) (6%, pH 2.1, 1 min). The specimens were analyzed under a Laser Scanning Confocal Microscope (n = 2/group) and the products’ DC were calculated. Data were subjected to 2-way repeated measures ANOVA and post-hoc Bonferroni (permeability analysis), to paired t-test (for specimens treated with Icon) and to t-test (DC analysis) (α < 0.05).ResultsIcon showed the lowest LpTreat and LpEro values, while PBC and Gluma did not differ from each other under these conditions. Icon and PBC showed LpEro similar to a dentin with smear layer. Under the Laser Scanning Confocal Microscope, more deposits were noticeable on dentin after treating with PBC. Gluma presented the deepest penetration in dentin. The DC of PBC was the highest.SignificanceIcon caused the highest reduction on permeability values, followed by PBC and Gluma. PBC generated more deposits covering dentin and seemed to be more efficient after an erosive challenge. The association of a polymeric resin with inorganic ion-releasing fillers seem to be a great strategy to manage dentin hypersensitivity under erosive conditions.     

牙本质磷蛋白诱导矿化作用的研究

目的：探讨牙本质磷蛋白（dentin phosphoprotein,DPP)诱导矿化的作用。方法：在体外矿化系统中利用入DPP与EAH－Sepharose 4B凝胶颗粒结合进行诱导矿化实验，通过扫描电镜观察生成物的形貌变化，X线衍射及等离子发射光谱分析生成物的组分和结构。结果：结合有人DPP的凝胶颗粒表面有矿化物形成，该矿化物钙磷比约为1．33，其X线衍射结果与羟基磷灰石更为相似。结论：人DPP与一定的支持物紧密结合后具有诱导矿化的作用。     

Effect of Proanthocyanidin-enriched extracts on the inhibition of wear and degradation of dentin demineralized organic matrix

ObjectivesThe aim of this study was to evaluate the effect of Cranberry and Grape seed-enriched extract gels in inhibiting wear and degradation of demineralized organic matrix (DOM).Design225 dentin specimens obtained from bovine incisors were randomly allocated into 5 groups (n = 45): 10% Grape seed extract gel (GSE), 10% Cranberry extract gel (CE), 0.012% Chlorhexidine gel (CX), 1.23% NaF gel (F), and no active compound gel (P, placebo). Before the treatments, samples were demineralized by immersion in 0.87 M citric acid, pH 2.3 (36 h). Then, the studied gels were applied once over dentin for 1 min. Next, the samples were immersed in artificial saliva containing collagenase obtained from Clostridium histolyticum for 5 days. The response variable for dentin wear was depth of dentin loss measured by profilometry and for collagen degradation was hydroxyproline determination. Data were analyzed by ANOVA followed by Tukey's test and Pearson Correlation Test (p < 0.05).ResultsGrape seed extract significantly reduced dentin wear compared to the other groups (p < 0.05). Cranberry extract and Chlorhexidine did not differ statistically and were able to reduce wear when compared to NaF and placebo treatments. The hydroxyproline analysis showed that there was no significant difference among groups for all treatments (p < 0.05). Correlation analysis showed a significant correlation between the amount of degraded DOM evaluated by profilometry and the determination of hydroxyproline.ConclusionCranberry extract was able to reduce the dentin wear and collagen degradation, likely due to the proanthocyanidin content and its action. Therefore, Cranberry could be suggested as an interesting natural-based agent to prevent dentin erosion.     

Effect of fluoride gels supplemented with sodium trimetaphosphate on enamel erosion and abrasion: In vitro study

Objective

This in vitro study aims to evaluate the effect of low fluoride (F) gel associate sodium trimetaphosphate (TMP) on erosion with or without abrasion.

Design

Enamel blocks (4 mm × 4 mm) selected through surface hardness (SH) is divided into five groups (n = 12): gel without F and TMP (placebo), gel containing 4500 ppm F (4500), gel containing 4500 ppm F plus TMP5% (4500 TMP5%), gel containing 9000 ppm F (9000), and gel containing 12,300 ppm F (acid gel). Those groups were additionally subdivided into conditions of erosion (Ero) and of erosion plus abrasion (Ero/Abra). The blocks have undergone a single application of gel on the first day of the study. The erosion challenge was produced by Sprite Zero^® for five minutes four times a day and abrasion was carried out by machine brushing for 15 s. After the challenges, the surface hardness (%SH), wear and cross-sectional hardness (ΔKHN) were analyzed. The data were analyzed using a 2-way ANOVA test followed by a Student-Newman–Keuls (p < 0.05).

Results

Lower values of %SH, wear and ΔKHN were observed for erosion challenge (p < 0.001). The %SH was lower in groups treated with fluoride gels, differing in the placebo (p < 0.05). With addition of TMP to the gel 4500, enamel wear was lower when compared with another groups (p < 0.05).

Conclusion

In vitro conditions, the 4500 5%TMP gel showed greatest effect against erosion and erosion/abrasion.     

Effects of dentin tubule occlusion by dentifrice containing a PVM/MA bioadhesive copolymer in a silica base

Objective

To study the effectiveness of a dentifrice containing polymethyl vinyl ether-maleic acid (PVM/MA) copolymer in a silica base in occluding dentin tubules for treatment of dentin sensitivity.

Methods

Thirty-two human dentin discs were divided into two groups and brushed in the morning for 30 s each to study the dentifrices with and without PVM/MA copolymer. Dentin tubule occlusion and dentin permeability were evaluated with a focus variation three dimensional vertical scanning microscope (IFM) and electrochemical impedance spectroscopy (EIS). After second brushing for 30 s in the afternoon the dentin discs were immersed in saliva for 16 h and then subjected to erosion using orange juice for 10 min. The effects of saliva and orange juice on tubule occlusion used in the study of dentifrices were further evaluated with IFM.

Results

On average 97.7% of the dentin tubules were occluded after brushing in the PVM/MA group, as compared to 13.3% in the control group (p < 0.0001). EIS showed that the impedance of the dentin disc increased after treatment with PVM/MA but not in the control group (p < 0.05). After 16 h of storage in saliva and 10 min of erosion by orange juice, 86% of the dentin tubules remained occluded in the PVM/MA treated dentifrice. The sizes of the tubule openings were increased after orange juice erosion in the control group but not in the PVM/MA group.

Conclusion

Dentifrice containing PVM/MA copolymer in a silica base effectively occluded dentin tubules. The intra-tubular plugs were resistant to saliva and orange juice challenges.     

The erosion-inhibiting effect of TiF4, SnF2, and NaF solutions on pellicle-covered enamel in vitro

Objective. The aim of this study was to compare the protective effect of TiF₄, SnF₂, 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 TiF₄, SnF₂, 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, TiF₄ reduced enamel loss by 100% after 2 min and by 24% after 8 min of acid exposure. The corresponding values for SnF₂ 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. TiF₄ gave the best protection against acid attack. SnF₂ provided significant protection only after 2 min of acid exposure, while NaF had no significant protective effect.     

Effect of a single application of TiF4 and NaF varnishes and solutions on dentin erosion in vitro

Objectives

This in vitro study aimed to analyse the effect of a single application of TiF₄ and NaF varnishes and solutions to protect against dentin erosion.

Methods

Bovine root dentin samples were pre-treated with NaF-Duraphat varnish (2.26%F, pH 4.5), NaF/CaF₂-Duofluorid varnish (5.63%F, pH 8.0), NaF-experimental varnish (2.45%F, pH 4.5), TiF₄-experimental varnish (2.45%F, pH 1.2), NaF solution (2.26%F, pH 4.5), TiF₄ solution (2.45%F, pH 1.2) and placebo varnish (pH 5.0, no-F varnish control). Controls remained untreated. Ten samples in each group were then subjected to an erosive demineralisation (Sprite Zero, 4× 90 s/day) and remineralisation (artificial saliva, between the erosive cycles) cycling for 5 days. Dentin loss was measured profilometrically after pre-treatment and after 1, 3 and 5 days of de-remineralisation cycling. The data were statistically analysed by two-way ANOVA and Bonferroni's post hoc test (p < 0.05).

Results

After pre-treatment, TiF₄ solution significantly induced surface loss (1.08 ± 0.53 μm). Only Duraphat reduced the dentin loss overtime, but it did not significantly differ from placebo varnish (at 3rd and 5th days) and TiF₄ varnish (at 3rd day).

Conclusions

Duraphat varnish seems to be the best option to partially reduce dentin erosion. However, the maintenance of the effects of this treatment after successive erosive challenges is limited.     

不同旋转器械对基牙牙本质表面粗糙度及显微形貌的影响

目的评价不同旋转器械对基牙牙本质表面粗糙度及显微形貌的影响,为临床牙体预备过程中旋转器械的选择使用提供参考。方法选择54颗离体牙,均分为3组,使用不同的预备方式对唇面进行预备。A组：标准金刚砂车针预备;B组：标准金刚砂车针预备,极细粒度金刚砂车针修整;C组：标准金刚砂车针预备,钨钢车针修整。之后用粗糙度仪测定牙本质表面粗糙度（Ra、Rq和Rz）,并进行扫描电镜观察,对其结果进行统计学处理。结果 3种预备方式后的牙本质表面粗糙度Ra存在显著差异（P〈0.05）;粗糙度由大到小依次为：A组〉B组〉C组。结论不同旋转器械切磨牙本质所得表面粗糙度不同,使用极细粒度金刚砂车针和钨钢车针修整可获得较为光滑的牙体预备体表面。     

The effect of an experimental 4% Tif4 varnish compared to NaF varnishes and 4% TiF4 solution on dental erosion in vitro

This in vitro study assessed the effect of an experimental 4% TiF(4) varnish compared to commercial NaF and NaF/CaF(2) varnishes and 4% TiF(4) solution on enamel erosion. For this, 72 bovine enamel specimens were randomly allocated to the following treatments: NaF varnish(2.26% F), NaF/CaF(2) varnish (5.63% F), 4% TiF(4) varnish (2.45% F), F-free placebo varnish, 4% TiF(4 )solution (2.45% F) and control (not treated). The varnishes were applied in a thin layer and removed after 6 h. The solution was applied to the enamel surface for 1 min. Then, the specimens were alternately de- and remineralized (6 times/day) in an artificial mouth for 5 days at 37 degrees C. Demineralization was performed with the beverage Sprite (1 min, 3 ml/min) and remineralization with artificial saliva (day: 59 min, 0.5 ml/min; during the night: 0.1 ml/min). The mean daily increment of erosion and the cumulative erosion data were tested using ANOVA and ANCOVA, respectively, followed by Tukey's test (alpha = 0.05). The mean daily erosion increments and cumulative erosion (micrometers) were significantly less for the TiF(4) varnish (0.30 +/- 0.11/0.65 +/- 0.75) than for the NaF varnish (0.58 +/- 0.11/1.47 +/- 1.07) or the NaF/CaF(2) varnish (0.62 +/- 0.10/1.68 +/- 1.17), which in turn showed significantly less erosion than the placebo varnish (0.78 +/- 0.12/2.05 +/- 1.43), TiF(4) solution (0.86 +/- 0.11/ 2.05 +/- 1.49) and control (0.77 +/- 0.16/2.06 +/- 1.49). In conclusion, the TiF(4) varnish seems to be a promising treatment to reduce enamel loss under mild erosive conditions.     

Protective effect of the in situ pellicle on dentin erosion - an ex vivo pilot study

AIM: The acquired pellicle is well known as an anti-erosive proteinaceous layer on enamel, but its protective properties on dentin have not been investigated in detail until now. The aim of the present ex vivo study was to evaluate the erosive effects on pellicle coated dentin. METHODS: Bovine dentin slabs were exposed to the oral cavity of one subject for 120 min for in situ pellicle formation. Subsequently, the slabs were incubated with HCl (pH 2.3) in vitro for 5 min and erosive calcium-release was measured photometrically. In addition, the acid treated specimens were evaluated by transmission electron microscopy (TEM). Pellicle free samples served as controls. RESULTS: Calcium erosion from the pellicle coated dentin slabs amounted to 23.5+/-2.9 microg Ca/min (pellicle free samples: 32.2+/-4.2 microg Ca/min). The difference was statistically significant (p < or = 0.05). In pellicle coated as well as in uncoated dentin samples, TEM-evaluation showed a demineralised dentinal surface layer which thickness ranged between 3 and 6 microm. The pellicle itself was partially dissolved but not removed by hydrochloric acid treatment. CONCLUSION: The protective properties of the acquired pellicle against an erosive challenge of the dentinal surface are limited. The dentinal pellicle functions like an ion permeable network rather than a barrier.