Comparison of Fluoride Ion Release from Fluoride Gel in Various Solvents

Concentration of Fluoride in Saliva After Fluoride Gel Application: A Randomised Clinical Trial

OBJECTIVE

The aim of this randomised clinical trial (RCT) was to assess the concentration of fluoride ions in saliva after applying fluoride gel and to examine the extent to which rinsing the mouth with water affects the content of fluoride ions in saliva as opposed to no rinsing after brushing teeth with gel.

METHODS

This single-blind RCT was conducted amongst a group of students (N = 103) and consisted of a questionnaire, clinical examination, saliva collection, and laboratory analysis. After saliva samples were collected, the students brushed their teeth for 2 minutes with Elmex Gelée (Colgate-Palmolive). Next, saliva was collected after 15 and 60 minutes from Group A (spitting out saliva after brushing) and from Group B (spitting out and rinsing with water after brushing). Statistical analysis was performed using a t test to compare the means between the groups.

RESULTS

Fifteen minutes after brushing, the level of fluoride increased in Group A about 15-fold to 15.33 ± 14.73 ppm and in Group B about 6-fold to 6.19 ± 5.97 ppm (P < .001). After 60 minutes, in Group A it decreased to 1.68 ± 0.83 ppm and in Group B to 0.60 ± 0.37 ppm (P < .001).

CONCLUSIONS

The use of fluoride gel in the absence of mouth rinsing produced significantly higher level and a concentration of fluoride in saliva. A post-gel brushing without rinsing might be suitable for patients at high risk for caries. Hence fruther research on the effect of a mouth rinse after use of fluoride gels is eesential to confirm our findings, and to promulgate evidence-based recommendations.

Nanofluorapatite Hydrogels in the Treatment of Dentin Hypersensitivity: A Study of Physiochemical Properties and Fluoride Release

The aim of this work was to prepare a new hydrogel based on nanohydroxyapatite (nFAP, 10% w/w) and fluorides (4% w/w), both of which are used as sources of fluoride ions in the treatment of dentin hypersensitivity, and to characterize its physicochemical properties. The release of fluoride ions from 3 gels (G-F, G-F-nFAP, and G-nFAP gel) was controlled in Fusayama–Meyer artificial saliva at pH 4.5, 6.6, and 8.0. The properties of the formulations were determined by an analysis of viscosity, a shear rate test, a swelling study, and gel aging. Various methods, i.e., FT-IR spectroscopy, UV-VIS spectroscopy, and thermogravimetric, electrochemical, and rheological analysis, were used for the experiment. The profiles of fluoride release indicate that the amount of fluoride ions released increases with a decrease in the pH value. The low pH value facilitated water absorption by the hydrogel, which was also confirmed by the swelling test, and it promoted the exchange of ions with the surrounding environment. Under conditions similar to physiological conditions (at pH 6.6), the amounts of fluorides released into artificial saliva were approximately 250 µg/cm2 and 300 µg/cm2 for the G-F-nFAP hydrogel and G-F hydrogel, respectively. The aging study and properties of the gels showed a loosening of the gel network structure. The Casson rheological model was used to assess the rheological properties of the non-Newtonian fluids. Hydrogels consisting of nanohydroxyapatite and sodium fluoride are promising biomaterials in the prevention and management of the dentin hypersensitivity.

Dual Action Nitric Oxide and Fluoride Ion-Releasing Hydrogels for Combating Dental Caries

Demineralization and breakdown of tooth enamel are characterized by a condition called dental caries or tooth decay, which is caused by two main factors: (1) highly acidic food intake without proper oral hygiene and (2) overactive oral bacteria generating acidic metabolic byproducts. Fluoride treatments have been shown to help rebuild the hydroxyapatite structures that make up 98% of enamel but do not tackle the bacterial overload that continues to threaten future demineralization. Herein, we have created a dual-function Pluronic F127-alginate hydrogel with nitric oxide (NO)- and fluoride-releasing capabilities for the two-pronged treatment of dental caries. Analysis of the hydrogels demonstrated porous, shear-thinning behaviors with tunable mechanical properties. Varying the weight percent of the NO donor S-nitrosoglutathione (GSNO) within the hydrogel enabled physiologically actionable NO release over 4 h, with the fabricated gels demonstrating storage stability over 21 days. This NO-releasing capability resulted in a 97.59% reduction of viable Streptococcus mutans in the planktonic state over 4 h and reduced the preformed biofilm mass by 48.8% after 24 h. Delivery of fluoride ions was confirmed by a fluoride-sensitive electrode, with release levels resulting in the significant prevention of demineralization of hydroxyapatite discs after treatment with an acidic demineralization solution. Exposure to human gingival fibroblasts and human osteoblasts showed cytocompatibility of the hydrogel, demonstrating the potential for the successful treatment of dental caries in patients.

Direct Induced Effects of Standard and Modified Radiotherapy Protocol on Surface Structure of Hard Dental Tissue

Introduction

Radiotherapy is used to treat neo plasmatic lesions and the common side effects of this process are pain, swelling and sensitivity of mucous membranes in domain of radiation, reduced salivation, caries, and periodontal disease and, in total, low life quality. The purpose of this research was to estimate the outcome of direct irradiation on physical and surface characteristics of hard dental tissues.

Materials and methods

Twenty, caries free third molars were involved in the research. Prior to different submission protocols, tooth halves were randomly assigned to subject and control groups by using a draw method. The first group (n=20) was submitted to conventional irradiation protocol (2 Gy for 35 days), second group (n=20) was submitted to one powerful, exploratory dose of 70 Gy. Each sample served as its own control. Radiation was performed with a linear accelerator radiotherapy unit. The surface microhardness and roughness were measured at the beginning (initially), and upon completion of irradiation procedure. The average change in microhardness and roughness after different treatments was compared by t-test for independent samples. Normality was tested by the Shapiro-Wilk test.

Results

Significant differences were found after the standard radiation protocol and the exploratory dose of 70 Gy, with decreased mean microhardness and increased mean roughness (p<0.001) of both hard dental tissues. Enamel and dentin surface microhardness and roughness did not vary notably with regards to different irradiation protocols.

Conclusion

Head and neck conventional irradiation protocol leads to possible breakdown of enamel and dentin with reduced microhardness and increased surface roughness regardless of used irradiation protocol.