Effect of organic versus inorganic fluoride on enamel microhardness: An in vitro study

Effects of topical fluoride on primary tooth enamel microhardness after diode laser treatment

Objectives

Tooth decay is controlled and prevented using fluorides. Specifically, a combination of laser irradiation and topical fluoride application can improve fluoride absorption. Although laser irradiation is recommended in traditional technology for caries prevention, little is known about the efficacy of caries-inhibiting laser diodes. Further, most studies have focused on permanent teeth. The objective of this study was to explore the effect of laser diode radiation mixed with topical fluoride on the enamel surface microhardness of primary teeth.

Material and method

The 60 primary teeth were divided into 60 plates. Baseline Vickers microhardness was established for each enamel surface. The samples were then divided into three groups. 4 % NaF varnish (group A) and 4 % NaF varnish using diode 2 and 3 W lasers (groups B and C, respectively). The final microhardness was measured and statistically evaluated using SPSS version 16. ANOVA was used to compare the means of the tested groups, which had a P-value of 0.05, indicating significance.

Result

The mean and standard deviation of microhardness for the different groups was tested. Group C (4 % NaF with a diode laser at 3 W) showed a higher average Vickers hardness (VHN) than Group B (4 % NaF with a diode laser at 2 W), whereas group A showed the lowest average VHN. There was a significant difference in microhardness between groups (P 0.05).

Conclusion

This study explored the effect of laser mixed with topical fluoride on enamel surface microhardness of primary teeth. The use of a diode laser (Quanta System, Italy) with a fluoride varnish applied to the enamel surface has a greater effect on the resistance of the enamel to caries.

Comparative evaluation of antibacterial efficacy of active oxygen containing versus other dentifrices against Streptococcus mutans count in children with early childhood caries: A clinico-microbiological study

Background

Fluoridated dentifrices have been used for the prevention of dental caries since ages. However, to avoid the risk of fluorosis, the use of newer nonfluoridated options in dentifrices has shown a great interest in reducing Streptococcus mutans (SM) in early childhood caries (ECC).

Aim

The study aimed to evaluate the antimicrobial efficacy of active oxygen (AO)-based dentifrice with amine fluoride (AF)-, sodium monofluorophosphate (SMP)-, herbal (HB)-, and tricalcium phosphate (TCP)-based dentifrices on SM count in children with ECC.

Materials and Methods

Two hundred and fifty children aged 3-6 years with def ≥4 were selected and randomly divided into five groups of 50 each, based on the type of dentifrices used; Group I: AO-based, Group II: TCP, Group III: SMP, Group IV: AF, and Group V: HB dentifrice, and were asked to brush twice daily for 15 days. The saliva samples were collected at baseline, and after 15 days, cultured for SM colonies count.

Results

Difference in colony-forming units (CFU)/ml between baseline and 15 days was highly significant in all the five groups (P < 0.001). Significant difference was observed in SM count after 15 days between Groups I and IV (P = 0.017), while nonsignificant differences were seen when compared with Groups II, III, and V (P = 0.975, 0.137, and 0.992).

Conclusions

All the dentifrices were efficacious in reducing SM count in children with ECC. Although AO dentifrice showed superior results when compared to SMP, TCP, and HB, it did not prove to be superior to AF.

Salivary fluoride concentration following toothbrushing with and without rinsing: a randomised controlled trial

Background

Caries prevalence has declined significantly since the introduction of fluoridated toothpaste. There have been several developments regarding specific active fluoride ingredients but not enough evidence to support one over the other. The purpose of this double-blind randomized controlled trial was to compare salivary fluoride concentrations of different fluoride formulations in the form of toothpaste with and without post-brushing water rinsing in adults.

Methods

The study included 120 participants who were randomly assigned to one of 12 groups (10 participants/group). The toothpaste formulas investigated included (1) fluoride-free (0 ppmF); (2) sodium fluoride (1450 ppmF); (3) sodium monofluorophosphate (1450 ppmF); (4) sodium fluoride and monofluorophosphate combined (1450 ppmF); (5) stannous fluoride and sodium fluoride combined (1450 ppmF); and (6) amine fluoride (1400 ppmF). Block randomisation was used to assign each participant to one of the 12 groups. Participants brushed with 1.0 g of one of the six different toothpaste formulations either with or without post-brushing water rinsing. Saliva was collected at six different times (baseline and at 1, 15, 30, 60, and 90 min/s post-brushing). Samples were analysed using a fluoride ion-specific sensitive electrode connected to an ion analyser.

Results

The demographic characteristics of the participants were not significantly different among the groups (P > 0.05). Time, toothpaste formulation, and post-brushing rinsing routines had significant effects on saliva fluoride retention (P < 0.05). Amine fluoride-containing toothpaste was the only formula that showed statistically significantly higher concentrations of salivary fluoride at 90 min in both the rinsing and non-rinsing groups. Sodium monofluorophosphate toothpaste did not result in a significant difference compared to the control group at any time point, in both rinsing and non-rinsing groups.

Conclusions

Based on the results from this study, no rinsing after toothbrushing in adults can be recommended when sodium monofluorophosphate containing toothpaste formula is used. It also concludes that amine fluoride resulted in a significantly higher saliva fluoride concentration at 90 min in both the rinsing and non-rinsing groups compared to other fluoride toothpaste formulations.

Registry: Protocol Registration and Results System (ClinicalTrials.gov).

Clinical trial registration number: NCT02740803 (15/04/2016).

Effect of Fluoride Varnish and Dentifrices and Its Combination on Deciduous Enamel Demineralization: An In vitro Study

Introduction:

Dental caries remains the most important dental health problem in developing countries. Application of varnish on tooth surfaces is shown to promote the uptake of firmly bound fluoride by enamel, which is considered important. Along with the incorporation of fluoride into the crystalline lattice, there is formation of calcium fluoride compounds on enamel.

Methodology:

Seventy deciduous canines were covered with nail polish. A window measuring 4 mm × 4 mm was left on their buccal surface, These were randomly assigned to seven groups (n = 6): S: sound enamel not subjected to any regimen or treatment; N: negative control, subjected to the pH-cycling regimen without any treatment; D1 and D2: subjected to the pH-cycling regimen and treated two times daily with 1100 and 500 ppm F dentifrice, respectively; VF: fluoride varnish (subjected to F-varnish before and in the middle of the pH-cycling regimen); and VF + D1 and VF + D2. After a period of 10 days, sectioning of teeth was done, and enamel demineralization was measured.

Results:

The combination of dentifrice and varnish (groups VF + D1 and VF + D2) significantly reduced demineralization compared with the N group at all distances evaluated (P < 0.05), but the combination did not differ from the dentifrice groups at most distances from the surface (P > 0.05).

Conclusion:

The results of this study suggest that the combination of F-varnish with dentifrices containing 500 or 1100 ppm F is not more effective in reducing demineralization in primary teeth than the isolated effect of dentifrice containing 1100 ppm.

Genotoxicity of non-alcoholic mouth rinses: A micronucleus and nuclear abnormalities study with fluorescent microscopy

AIM

The aim of the present study was to evaluate the genotoxicity of non-alcoholic mouth rinses on buccal epithelial cells using a micronucleus test.

METHODS

A total of 105 patients were selected and randomly divided into five groups. Four different mouth rinses and normal saline were given for 2 weeks' duration, and cytological smears were collected before and after exposure. These smears were subjected to micronucleus (MN) and other nuclear abnormalities (ONA) tests using acridine orange stain, and their frequencies were obtained in 500 buccal epithelial cells. The statistical analysis included mean, χ² -test, analysis of variance, and post-hoc analysis by Bonferroni test.

RESULTS

Micronucleated cells (P < .00) and MN (P < .00) were higher in individuals exposed to chlorhexidine (CHX), followed by chlorine dioxide (ClO₂ ), potassium nitrate (KNO₃ ), and sodium fluoride (NaF), amine fluoride (AmF), and normal saline. ONA were greater (P < .00) in individuals exposed to CHX, followed by ClO₂ , AmF, KNO₃ , and NaF and normal saline. Overall, the results showed that genotoxic damage was greater in the case of CHX, followed by ClO₂ , KNO₃ , and NaF, AmF, and normal saline.

CONCLUSION

Chronic exposure to mouth rinses can cause genotoxic damage to buccal epithelial cells. Long-term injudicious and inadvertent use of mouth rinses should be discouraged.

Effects of nicomethanol hydrofluoride on dental enamel and synthetic apatites: a role for anti-caries protection

Aim

To analyse the anti-caries properties of nicomethanol hydrofluoride (NH) and the benefit of its combination with siliglycol, a coating agent.

Methods

Fluoride (F) uptake by dental enamel and synthetic apatite treated with NH was measured in vitro and compared to treatment with mineral fluorides. The addition of siliglycol was also tested. The effect of NH (as a mouthwash) on salivary pH was also investigated in healthy human subjects and compared to the effect of a placebo and of nicomethanol alone.

Results

In vitro experiments showed a greater and faster F uptake on dental enamel or synthetic apatite treated with NH compared to sodium fluoride. F uptake was improved further by the addition of siliglycol. In healthy human subjects, pH reduction was strongly inhibited 5 min after two mouthrinses with NH. This effect was less pronounced but still statistically significant at 15 and 30 min (p < 0.05).

Conclusions

NH was able to promote the fixation of F ions and strengthen the dental structure. Its combination with siliglycol further improved F uptake by the tooth and the control/inhibition of dental biofilm development.

In Vitro Evaluation of Enamel Microhardness after Application of Two Types of Fluoride Varnish

INTRODUCTION

Use of fluoride compounds is one of the most effective ways of preventing decay and among these varnishes have high acceptance among different fluoride products.

AIM

Hence, the aim of this research was to evaluate the micro-hardness of tooth enamel after the usage of two different commercial products of fluoride varnish.

MATERIALS AND METHODS

This in vitro experimental study was performed on 51 extracted premolar teeth. The teeth were divided randomly into three 17-membered groups. The first group received Duraflor varnish, the second group received Ariadent Iranian varnish while the third group received no treatment. Micro hardness of tooth enamel was measured utilizing Vickers method before and after the use of fluoride varnish. ANOVA, Tukey, and Wilcoxon statistical tests were utilized for statistical analysis of data.

RESULTS

The comparison of mean change in micro hardness before and after the use of fluoride showed that increase in micro hardness in Duraflor varnish and Ariadent varnish group was significant when compared to control group (p<0.05) but no significant statistical difference was observed in terms of mean of micro hardness after intervention between two groups of Duraflor varnish and Ariadent varnish (p>0.05).

CONCLUSION

According to the findings, the use of fluoride significantly increased the enamel micro hardness which did not show a significant difference between two groups of Duraflor varnish and Ariadent varnish.

Remineralization ability of sodium fluoride on the microhardness of enamel, dentin, and dentinoenamel junction: An in vitro study

Aim:

Dental tissues such as enamel, dentinoenamel junction (DEJ), dentin, and root dentin can react differently to demineralization and remineralization. The aim of this study was to evaluate the remineralization ability of sodium fluoride on the microhardness of enamel, dentin, and dentinoenamel junction.

Materials and Methods:

Ten extracted third molar teeth were sectioned mesiodistally to form control and test groups. For the test group, initial demineralization was done with acetic acid for 24 h followed by remineralization for 28 days by application of sodium fluoride (226 ppm) for 2 min twice a day. Vickers microhardness test was done to control and test groups at different sites after initial demineralization and on the 3^rd, 5^th, 7^th, 14^th, and 28^th day of remineralization.

Statistical Analysis Used:

Data were analyzed with one-way analysis of variance and post hoc test with a significance level of P < 0.001 with SPSS (21) software.

Results:

Microhardness values in the demineralization group were significantly lower than controls (P < 0.001). Evaluation of remineralization samples showed that microhardness similar to control values were achieved at the 3^rd day in root predentin and on the 5^th day in coronal dentin and coronal predentin. On the 7^th day, remineralization coronal predentin was significantly higher than the control (P < 0.001). On the 14^th day, DEJ axial zone and root dentin were similar to control and coronal dentin was significantly higher than the control (P < 0.001). Enamel was similar to control on the 28^th day. Microhardness of DEJ-cusp tip and DEJ-center of the fissure was significantly lower than control even at the 28^th day (P < 0.001).

Conclusion:

Long-term repeated application of sodium fluoride (226 ppm) can improve the microhardness of demineralized dental tissues on enamel, dentin, and DEJ-axial zone, except in the DEJ-cusp tip and DEJ-center of fissure.

Comparative evaluation and effect of organic and inorganic fluoride dentifrices on enamel microhardness: An in vitro study

Aim:

To compare and evaluate the microhardness of enamel surface after the application of organic fluoride and inorganic fluoride dentifrices.

Materials and Methods:

Twenty freshly extracted premolars were collected and decoronation of all the teeth was done at cementoenamel junction. The crowns were sectioned mesiodistally into two halves with the help of diamond disc, and then the subsequent forty samples kept in 1% citric acid for the demineralization and divided into two groups by simple randomization, that is, Group A (inorganic sodium fluoride dentifrice) and Group B (organic amine fluoride dentifrice). They were treated using same protocol for 3 min, daily twice for 7 days. Those samples preserved in artificial saliva in between treatment. The enamel surface microhardness evaluated using Vickers hardness test at base level, after demineralization, as well as after remineralization. Statistical analysis of surface microhardness obtained at different stages done by Student's t-test and P < 0.05 was considered statistically significant.

Results:

The samples which were treated with sodium fluoride (Group A) could not restore the mean microhardness after treatment to that of preoperative level whereas amine fluoride (Group B) treated samples showed a statistically significant increase in mean surface microhardness from baseline.

Conclusion:

Organic fluoride (amine fluoride) remineralization was more effective in restoring enamel microhardness than inorganic fluoride (sodium fluoride) remineralization.

Effect of carbon dioxide laser irradiation on enamel surface microhardness around orthodontic brackets

INTRODUCTION

In this study, we aimed to determine the effect of carbon dioxide laser irradiation on enamel surface microhardness.

METHODS

In this single-blind interventional clinical trial, 16 patients needing at least 2 premolars extracted for orthodontic purposes participated. In each subject, 1 premolar was treated with the carbon dioxide laser (beam diameter, 0.2 mm; power, 0.7 W); the other was exposed to a visible guiding light as the control. A t-loop was ligated to the bonded brackets to increase caries risk. After at least 2 months, the teeth were extracted, and the surface microhardness was measured. Scanning electron microscope evaluation was performed on 1 sample from each group. Normal distribution of the data was assessed by the Kolmogorov-Smirnov and Shapiro-Wilks tests. Mean microhardness values of the 2 groups were compared using paired t tests.

RESULTS

The data had normal distributions. Means and standard deviations of the microhardness in the laser-treated and control groups were 301.81 ± 94.29 and 183.9 ± 72.08 Vickers hardness numbers, respectively; this was different significantly (P <0.001). Scanning electron microscopy showed the enamel surface melting in the laser-treated specimens.

CONCLUSIONS

Carbon dioxide laser treatment results in higher enamel surface microhardness around orthodontic brackets. Patients at high risk of caries might benefit from this intervention. Exact control of the laser irradiation parameters is recommended.