Modified toothpaste application using prepared toothpaste delivering technique increases interproximal fluoride toothpaste delivery.

OBJECTIVES: We devised a "prepared toothpaste delivering technique" (PTD technique), a modified the application of toothpaste method for using fluoride toothpaste more effectively. This study aimed to investigate the change in viscosity and fluoride intake into hydroxyapatite of a toothpaste, and deliverability of fluoride toothpaste to the interproximal site with the PTD technique using an interproximal model. METHODS: Eight toothpaste samples were prepared at the following concentrations: ×1.00, ×1.25, ×1.50, ×1.75, ×2.00, ×3.00, ×4.00, and ×5.00. Viscosity of the toothpaste was measured by a Type-B viscometer. Dissolution rate of toothpaste and fluoride uptake into the hydroxy apatite pellet were analyzed by a fluoride selective electrode. Application paste volume and delivery rate was measured using interproximal model and image analysis software during using a finger brush front (FBF), finger brush back (FBB), and toothbrush. RESULTS: As the dilution ratio increased, the viscosity of the toothpaste decreased sharply, F uptake decreased, and dissolution rate increased. F uptake was significantly reduced when the toothpaste was diluted more than 1.75 times. Therefore, in order to improve the effectiveness of the fluoride toothpaste, it is important to deliver the toothpaste to interproximal areas and pit clefts at low dilution. It was observed that PTD technique can be effectively implemented by the finger brush. CONCLUSIONS: The use of a FBF surface in the analysis of an acrylic interproximal model could aid in applying pressure while blocking the space of the groove and preventing outflow of the toothpaste. It was considered that the PTD technique would improve the effects of the fluoride toothpaste, especially in the interproximal site.

Fluoride Levels in Unstimulated Whole Saliva following Clinical Application of Different 5% NaF Varnishes.

The aim of this study was to evaluate the fluoride release from differently formulated 5% NaF varnishes into unstimulated whole saliva in vivo. The fluoride concentration in unstimulated whole saliva was determined after the application of 3 different 5% NaF varnishes (5% NaF, 5% NaF + tricalcium phosphate [TCP], and 5% NaF + amorphous calcium phosphate [ACP]) or a placebo. Fifteen subjects were recruited and enrolled following Institutional Review Board approval based upon the inclusion/exclusion criteria of this study. A cross-over study design was used for the application of either one of the 5% NaF varnishes or a placebo. Unstimulated whole saliva was collected at baseline and at 1, 4, 6, 26, and 50 h following application and analyzed for supernatant ionic fluoride and whole fluoride by microdiffusion. Linear mixed-effects models (5% significance level) were used to determine the effects of varnish and time on the salivary fluoride concentration. The highest amount of fluoride in saliva was found 1 h after application of the fluoride varnishes, with no significant differences among the treatment varnishes with respect to whole fluoride but with lower levels for 5% NaF + ACP in the saliva supernatant. Salivary fluoride levels at 4, 6, and 26 h decreased at each time point and were generally significantly higher for 5% NaF and 5% NaF + TCP. After 50 h, fluoride levels in saliva for all groups were at or below baseline levels. In conclusion, the formulation of other ingredients in fluoride varnishes can affect the fluoride concentration in saliva. The reasons for this phenomenon warrant further investigation since it might affect efficacy of the treatment. This trial is registered at ClinicalTrials.gov (NCT01629290).

Children's Menu Diversity: Influence on Fluoride Absorption and Excretion.

AIM: The aim of this study is to determine the influence of children's menu diversity on the absorption and excretion of fluoride. MATERIALS AND METHODS: The experimental, longitudinal, quantitative study was carried out in a city without fluoridation in water supply. A total of 16 adult volunteers (>63.9 kg) participated in the study who, after a 12-hour fast, ingested two types of children's meals, whose quantity and diversity were determined after weighing the meals best consumed by children at a kindergarten in Campinas, Sao Paulo: Simple child meal (SCM; n = 8) and hearty child meal (HCM; n = 8). The fluoride gel residual after professional application (12,300 ppm, 30.75 mg F, pH = 4.65) was simulated 15 minutes after feeding. Saliva samples (in time intervals of 0, 15, 30, and 45 minutes and 1, 2, 3, 4, 6, and 12 hours after ingestion of the fluorine solution) and urine of the volunteers were analyzed at 24 hours. Fluoride concentrations were determined using a selective ion electrode. Data were analyzed by analysis of variance for repeated measurements (PROC MIXED)/Tukey-Kramer. RESULTS: The concentrations of fluoride in saliva at 0 and 15 minutes and after 6 hours were the same between groups (p > 0.05). From 30 minutes to 4 hours after ingestion, the SCM group showed a higher concentration of fluoride in the saliva, which has a higher absorption (p < 0.05). The fluoride concentration in the urine did not differ between groups at both collection times (p > 0.05), and for both, the fluoride concentration in the urine increased in the final measurement (p < 0.05). CONCLUSION: The children's menu diversity influenced the absorption of fluoride so that the topical application of fluoride should be performed in infants fed preferably after the fuller diet and following the established guidelines to ensure the safety of the procedure. CLINICAL SIGNIFICANCE: Knowledge of the influence of the children's menu diversity on fluoride metabolism after professional application is important so that the actions of fluoride therapy may be planned in a safer manner and be based on the reality of the universe of children.

Mechanism of Action of TiF4 on Dental Enamel Surface: SEM/EDX, KOH-Soluble F, and X-Ray Diffraction Analysis.

This in vitro study aimed to evaluate the action of TiF4 on sound and carious bovine and human enamel. Sound (S) and pre-demineralised (DE) bovine and human (primary and permanent) enamel samples were treated with TiF4 (pH 1.0) or NaF varnishes (pH 5.0), containing 0.95, 1.95, or 2.45% F for 12 h. The enamel surfaces were analysed using SEM-EDX (scanning electron microscopy/energy-dispersive X-ray spectroscopy) (n = 10, 5 S and 5 DE) and KOH-soluble fluoride was quantified (n = 20, 10 S and 10 DE). Hydroxyapatite powder produced by precipitation method was treated with the corresponding fluoride solutions for 1 min (n = 2). The formed compounds were detected using X-ray diffraction (XRD). All TiF4 varnishes produced a coating layer rich in Ti and F on all types of enamel surface, with micro-cracks in its extension. TiF4 (1.95 and 2.45% F) provided higher fluoride deposition than NaF, especially for bovine enamel (p < 0.0001). It also induced a higher fluoride deposition on DE samples compared to S samples (p < 0.0001), except for primary enamel. The Ti content was higher for bovine and human primary enamel than human permanent enamel, with some differences between S and DE. The XRD analysis showed that TiF4 induced the formation of new compounds such as CaF2, TiO2, and Ti(HPO4)2·H2O. In conclusion, TiF4 (>0.95% F) interacts better, when compared to NaF, with bovine and human primary enamel than with human permanent enamel. TiF4 provoked higher F deposition compared to NaF. Carious enamel showed higher F uptake than sound enamel by TiF4 application, while Ti uptake was dependent on the enamel condition and origin.

In vitro evaluation of surface properties of Pro Seal® and Opal® SealTM in preventing white spot lesions.

OBJECTIVES: To evaluate the surface properties of two commercially available sealants (Pro Seal® (PS) and Opal® SealTM (OS)) in terms of fluoride(F) release, biofilm formation of Streptococcus mutans and Lactobacillus and the ability to resist acid penetration. SETTING: University of Nebraska Medical Center. MATERIAL & METHODS: Discs of similar diameter and thickness were made from OS and PS. Discs were soaked in double-distilled water, and F released was measured with fluoride meter daily for 14 consecutive days, then at 21 and 28 days. Biofilm formation was evaluated with Streptococcus mutans and Lactobacilli grown on sealant discs using confocal microscopy. Extracted human teeth (n=8) with sealant-coated buccal surfaces and untreated lingual surfaces were exposed to 0.1M lactic acid(pH=4.5) to test the acid penetration. After 1-4 weeks of exposure, teeth were subjected to microhardness testing and SEM microscopy. RESULTS: PS released significantly higher levels of F than OS. PS showed more S. mutans adherence than OS, whereas Lactobacillus did not show any differences in adherence. Both sealants protected enamel surfaces, showing statistically significant difference in the depth of acid penetration compared to their unsealed control sides. CONCLUSION: F release was adequate to aid in remineralization, although clinically it would not likely aid in preventing demineralization as there was no prolonged release of F by both sealants tested. S. mutans adherence to OS surface was less compared to PS surface, which could be of relevance in biofilm formation and white spot lesions. Both sealants protected enamel surfaces from acid penetration.

Fluoride concentration in saliva and biofilm fluid following the application of three fluoride varnishes.

OBJECTIVE: Most of the commercially available fluoride varnishes (FV) have not been evaluated for their cariostatic properties. Consequently, the aim of this in vivo study was to investigate intra-oral fluoride retention and clearance patterns from three different FV. METHODS: Eighteen subjects (7-11 years) participated in a laboratory analyst-blinded, randomized, crossover study comparing the ability of 5% sodium fluoride varnishes (CavityShield-CS, Enamel Pro-EP, Vanish-V) to enhance fluoride concentrations in biofilm fluid, centrifuged and whole saliva over a period of 48h after a single FV application. RESULTS: Similar fluoride concentration×time patterns were noted for all investigated FV and studied variables, with the highest fluoride concentrations observed for the first biological sample collected after FV application (30min). Mean±SE (area under fluoride clearance curve) values were (µg F/g or ml×min): biofilm fluid - CS (472±191), EP (423±75),V (1264±279); centrifuged saliva - CS (42±7), EP (19±3),V (41±8); whole saliva - CS (68±11), EP (64±10),V (60±7).V delivered more fluoride to biofilm fluid than CS (p=0.0116) and EP (p=0.0065), which did not differ (p=0.27). For centrifuged saliva, CS and V were not significantly different (p=0.86), but resulted in higher fluoride retention than EP (p<0.0008). No significant differences among FV were observed for whole saliva (p=0.79). CONCLUSION: The present study has shown that FV vary in their ability to deliver fluoride intra-orally potentially related to formulation differences. To what extent the present findings relate to clinical efficacy remains, however, to be determined. CLINICAL SIGNIFICANCE: Clinical research that investigates fluoride release patterns into saliva and biofilm fluid from different FV products is insufficient. More research is needed to investigate different FV formulations for their efficacy in order to help clinicians make better evidence based treatment choices.

Urinary fluoride excretion after application of fluoride varnish and use of fluoride toothpaste in young children.

BACKGROUND: The efficacy and safety of combined use of topical fluoride products are essential issues that must be monitored. AIM: To assess urinary excretion of fluoride after application of two different dental varnishes containing 2.26% fluoride in 3- to 4-year-old children and to compare the levels with and without parallel use of fluoride toothpaste. DESIGN: Fifteen healthy children were enrolled to a randomized crossover trial that was performed in two parts: Part I with twice-daily tooth brushing with fluoride toothpaste and Part II with twice-daily brushing with a non-fluoride toothpaste. After a 1-week run-in period, 0.1 mL of the two fluoride varnishes (Duraphat and Profluorid Varnish) was topically applied in a randomized order. Baseline and experimental urine was collected during 6-h periods. The fluoride content was determined with an ion-sensitive electrode. RESULTS: There was a statistically significant increase in the 6-h fluoride excretion after application of both experimental varnishes, with and without parallel use of fluoride toothpaste (P < 0.01). When fluoridated toothpaste was used, the mean fluoride excretion was 0.20 mg/6 h after application of Duraphat and 0.29 mg/6 h after application of Profluorid Varnish (P = 0.18). CONCLUSIONS: Topical applications of 0.1 mL of fluoride varnish significantly increased the 6-h fluoride excretion. As some individuals displayed excretion levels exceeding the optimal fluoride exposure, a restricted use of fluoride toothpaste in connection with the varnish applications would decrease fluoride exposure.

Assessment of the Influence of Meal Type on Fluoride Absorption due to Ingestion of professionally Applied Gels.

AIMS: The aim of this study is to assess the influence of eating, prior to application of professionally used gels, on the rate of fluoride absorption due to the ingestion of 1.23% acidulated phosphate fluoride (APF). MATERIALS AND METHODS: After fasting for 12 hours, 16 adult volunteers (> 65 kg) ingested two types of meal: Breakfast (n = 8) and Lunch (n = 8). Accidental ingestion of fluoride gel used in molding trays was simulated (12,300 ppm; 61.5 mg F; pH = 4.65) 15 minutes after eating. After ingestion of the fluoride solution, 3 mL of venous blood were collected at the following times: Zero (before ingestion) and 15, 30, 45 minutes, 1, 2, and 3 hours. Fluoride concentrations in blood plasma were determined using an ion selective electrode. RESULTS: With the exception of time 0 (p > 0.05), the average blood plasma concentration of the breakfast group (BG) (0.34 ± 0.04 mg/L) was higher than that of the lunch group (LG) (0.24 ± 0.03 mg/L), with the moment of peak concentration being 2 hours after ingestion for both groups (BG = 0.4 mg/L; LG = 0.28 mg/L). CONCLUSION: Results reinforce the idea that eating before undergoing professional application of fluoride is a factor of extreme importance regarding its safety, and that the time following a patient's heaviest meal should be the time of choice for planning clinical care. CLINICAL SIGNIFICANCE: Our results should be considered when planning collective action that involves the application of the gel on children in a school environment, thus ensuring the procedure's safety.

The effect of fluoride varnishes on caries lesions: an in vitro investigation.

OBJECTIVES: The purpose of this study was to investigate the effect of five commercially available fluoride varnishes (FV) on caries lesions. MATERIALS AND METHODS: Ninety bovine enamel specimens were assigned to five varnish groups (n = 18). Early caries lesions were created in the specimens and characterized using Vickers surface microhardness number (VHN). FV was applied to each group of specimens. Immediately afterwards, 7.5 ml of artificial saliva (AS) were pipetted over each group of specimens, collected and renewed every 15 min for 6 h. AS samples were analyzed for fluoride using an ion-specific electrode. Enamel fluoride uptake (EFU) was determined using the acid etch technique. Each group was then subjected to a pH cycling regimen for 5 days after which VHN was determined again. One-way analysis of variance (ANOVA) was used for data analysis. RESULTS: FVs differed in their rehardening capability (highest mean value was for Enamel Pro = 32.3 ± 5.8 and lowest mean value was for Vanish = 18.9 ± 11.3). No significant difference in EFU was found among groups. Total fluoride release over 6 h was in the order of MI Varnish (303 µg/ml) > Enamel Pro (217 µg/ml) > Flor-Opal (153 µg/ml) > PreviDent(84 µg/ml) > Vanish(28 µg/ml). CONCLUSIONS: ΔVHN and fluoride release characteristics differ among FV products. These differences may be attributed to the different compositions and physical properties of the tested FV. CLINICAL RELEVANCE: Fundamental, comparable research on FV and how different formulations affect early caries lesion rehardening, fluoride release into saliva, and uptake by teeth is scarce.

Fluoride Varnishes--Is There a Correlation Between Fluoride Release and Deposition on Enamel?

PURPOSE: Fluoride uptake of enamel after application of fluoride varnishes was compared with fluoride release into artificial saliva. The hypothesis was that fluoride uptake is higher for products exhibiting faster fluoride release. MATERIALS AND METHODS: Fluoride varnishes, i.e. Fluor Protector S, Duraphat, MI Varnish, Clinpro White Varnish, Profluorid Varnish and Enamel Pro Varnish were applied on bovine enamel specimens. Subsequently, specimens were incubated in artificial saliva. After removal of the varnishes, surface bound fluoride was extracted with potassium hydroxide and measured with an ion-selective electrode. Structurally bound fluoride was etched from the same specimens with perchloric acid. Fluoride release of varnish films into artificial saliva was measured for comparison. RESULTS: After 4 h in artificial saliva, the highest total enamel fluoride uptake of 47.9 µg F·cm-² was found with Fluor Protector S, followed by Enamel Pro Varnish with 22.1 µg F·cm-². The other products ranged between 12-16 µg F·cm-². This was several times higher than the negative control. Fluoride uptake did not correlate with release into artificial saliva. During the first 4 h, Duraphat released the lowest and MI Varnish the highest amount of fluoride with 7.7 and 249 µg F·cm-², respectively. The fluoride uptake of these two products was not statistically different. CONCLUSION: Enamel fluoride uptake cannot be predicted from the fluoride release rate of a product. Hence, based on the results of this study, fluoride release into artificial saliva is no measure for the efficacy of a fluoride varnish.

Laboratory investigations into the potential anticaries efficacy of fluoride varnishes.

PURPOSE: The purpose of this study was to investigate the potential anticaries efficacy of fluoride varnishes (FVs) by studying their ability to reharden and deliver fluoride to carious lesions and to release fluoride into saliva. METHODS: Enamel carious lesions were created and allocated to 24 groups (11 FVs with two FV incubation times and two control groups) based on Knoop microhardness test values. FVs were applied to lesions, which were incubated in artificial saliva for two or six hours, with saliva being renewed hourly. FV was removed and lesions were remineralized in artificial saliva for 22 hours. Microhardness was measured and enamel fluoride uptake (EFU) was determined. Saliva samples (six-hour groups) were analyzed to determine fluoride release characteristics. Data were analyzed using analysis of variance. RESULTS: FVs differed considerably in their ability to reharden and deliver fluoride to carious lesions and in their fluoride release characteristics. Little consistency was found between investigated study variables for virtually all tested FVs. For example, a particular FV showed the highest EFU and fluoride release values but the lowest rehardening value. A longer FV contact time led to increased EFU for five of the 11 FVs. Some FVs delivered more fluoride to lesions in two hours than others did in six hours. CONCLUSION: Fluoride varnishes differ greatly in their in vitro anticaries efficacy.

Ion release from calcium and fluoride containing dental varnishes.

BACKGROUND: A range of dental varnishes have been commercialized recently that contain calcium and inorganic phosphate in addition to fluoride. The aim of this study was to analyse the fluoride, calcium and inorganic phosphate ion release from: (1) MI Varnish containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP); (2) Clinpro White containing functionalized tricalcium phosphate (fTCP); (3) Enamel Pro containing amorphous calcium phosphate; (4) Bifluorid 5 containing calcium fluoride; and (5) Duraphat (no added calcium control). METHODS: The varnishes were applied to a standardized surface area of polyvinyl chloride (n = 7 per group) and immersed in 25 g of distilled deionized water which was changed at 1, 4, 24, 72 and 168 hours. The ion release was determined by ion chromatography and expressed as µmol (cumulative) per gram of varnish. RESULTS: All varnishes released measurable fluoride and calcium, however only MI Varnish and Enamel Pro released significant levels of inorganic phosphate. At 24 hours the order of cumulative fluoride release was: 1>3>4>2=5 with 1 significantly higher (p < 0.05) than the rest. At 72 and 168 hours, the cumulative calcium release was: 1>4>3>2=5 with 1 significantly higher (p < 0.05) than the rest. CONCLUSIONS: MI Varnish containing CPP-ACP had the highest release of calcium and fluoride ions.

Enhanced penetration of fluoride particles into bovine enamel by combining dielectrophoresis with AC electroosmosis.

Fluoride deposition into the pores of enamel is necessary at high concentrations to reduce enamel demineralization and with a high degree of penetration to account for loss by ingestion. Current diffusion and electrochemical methods are inadequate for effectively transporting fluoride greater than 20 µm into enamel. The study explores the coupling of dielectrophoresis (DEP) and AC electroosmosis (ACEO) to selectively concentrate fluoride particles from fluoride gel excipients and enhance their penetration into enamel. By measuring the frequency response of approximately 10-µm-sized sodium fluoride particles in an aqueous gel media, appropriate frequencies for positive DEP, negative DEP, and ACEO are identified. An assembly composed of two cross-planar interdigitated electrode (IDE) arrays with open slots is driven successively by fields at appropriate frequencies to drive fluoride particles through the slots of the IDE and into the enamel pores using a combination of DEP and ACEO methods. Fluoride uptake and penetration of 1.23% acidulated phosphate fluoride gel into bovine tooth enamel at various depths is measured using wavelength dispersive spectrometry to compare deposition by diffusion, DEP, and DEP plus ACEO. Fluoride levels in all DEP groups were significantly higher than diffusion groups at depths 10 and 20 µm. The highest fluoride concentrations at 10, 20, 50, and 100 µm depths occur under deposition conditions combining DEP with ACEO. Fluoride levels at 50 µm were equivalent to long-term prophylactic exposure. These methods may potentially benefit populations at high risk for development of caries and periodontal disease, including underserved children and disparate groups.

The in vivo efficacy of Fluorinex topical fluoridation treatment.

OBJECTIVE: This randomized, single-controlled study was performed to validate in vivo the efficacy of single Fluorinex treatment by examining fluoride incorporation into enamel using electron microscopy. METHOD AND MATERIALS: Twenty healthy participants referred for routine dental treatment which also required extractions of at least two teeth as part of their treatment plan were included in this study. For each participant, one randomly selected tooth was extracted and sent for blind electron microscopic fluoride assay (control, C). Next, following a single Fluorinex treatment, the second (test, T) tooth was extracted and sent for the same assay. Intra-individual and intergroup fluoride content comparisons were performed, between control and test teeth. RESULTS: Highly significant intra-individual and intergroup differences were found between the treated and untreated teeth. Fluoride atomic percent (at%) and weight percent (wt%) estimated least squares means of untreated group were found to be 0.56 and 0.48, and in the treated group 17.35 and 14.35. This increase in fluoride at% [16.78 ± 2.3 (SE)], was also significant statistically (P < .0001); likewise, the increase in fluoride wt % [13.86 ± 1.97 (SE)] was similarly significant (P < .0001). The system was well tolerated by the participants with minimal transitional mild side effects. CONCLUSION: In vivo fluoride application using the active Fluorinex system resulted in a significant increase of fluoride content in the enamel of adult permanent teeth compared to untreated internal controls.

Short term serum pharmacokinetics of diammine silver fluoride after oral application.

BACKGROUND: There is growing interest in the use of diammine silver fluoride (DSF) as a topical agent to treat dentin hypersensitivity and dental caries as gauged by increasing published research from many parts of the world. While DSF has been available in various formulations for many years, most of its pharmacokinetic aspects within the therapeutic concentration range have never been fully characterized. METHODS: This preliminary study determined the applied doses (3 teeth treated), maximum serum concentrations, and time to maximum serum concentration for fluoride and silver in 6 adults over 4 h. Fluoride was determined using the indirect diffusion method with a fluoride selective electrode, and silver was determined using inductively coupled plasma-mass spectrometry. The mean amount of DSF solution applied to the 3 teeth was 7.57 mg (6.04 µL). RESULTS: Over the 4 hour observation period, the mean maximum serum concentrations were 1.86 µmol/L for fluoride and 206 nmol/L for silver. These maximums were reached 3.0 h and 2.5 h for fluoride and silver, respectively. CONCLUSIONS: Fluoride exposure was below the U.S. Environmental Protection Agency (EPA) oral reference dose. Silver exposure exceeded the EPA oral reference dose for cumulative daily exposure over a lifetime, but for occasional use was well below concentrations associated with toxicity. This preliminary study suggests that serum concentrations of fluoride and silver after topical application of DSF should pose little toxicity risk when used in adults. CLINICAL TRIALS REGISTRATION: NCT01664871.

Diode laser irradiation and fluoride uptake in human teeth.

AIM: To evaluate chemically the effects of diode laser on fluoride uptake before and after laser irradiation of enamel surfaces. METHODS: Crowns of 20 sound human teeth were halved and a 3 x 3 mm acid-resistant varnish uncovered window left for: A) no treatment; B) fluoride (Elmex gel); C) diode (fluoride + diode laser); D) diode (diode laser + fluoride). The dental surfaces were analysed using a fluoride ion-selective electrode, in order to evaluate the fluoride treatment in combination with a diode laser. Also, to investigate laser-induced compositional changes (contents in F(-)) in enamel before/after laser irradiation and topical fluoride application. RESULTS: The mean ± SD of fluoride uptake of teeth of group A was 1.55 ± 0.89 mg/l. Mean fluoride uptake increased sevenfold after fluoride gel treatment: 10.51 ± 3.38 mg/l for group B, up to 15 times after gel and laser treatment: 23.62 ± 3.58 mg/l for group C and was 22.7 ± 4.60 mg/l for group D (diode laser before fluoride application). The Kruskal Wallis test indicated a statistically significant effect of fluoride uptake for all three treatments (p<0.001). The Student-Newman-Keuls multiple comparison test indicated a statistically significant increase of fluoride uptake before and after all treatments, and also a statistically significant difference for laser treatment versus fluoride gel. However, there was no statistically significance difference between laser groups. CONCLUSIONS: There is an enhanced capability of lasers to increase fluoride uptake of enamel and providing protection to enamel surface from acid attack.

Comparison of effects of diode laser and CO2 laser on human teeth and their usefulness in topical fluoridation.

Various authors have reported more effective fluoridation from the use of lasers combined with topical fluoride than from conventional topical fluoridation. Besides the beneficial effect of lasers in reducing the acid solubility of an enamel surface, they can also increase the uptake of fluoride. The study objectives were to compare the action of CO(2) and GaAlAs diode lasers on dental enamel and their effects on pulp temperature and enamel fluoride uptake. Different groups of selected enamel surfaces were treated with amine fluoride and irradiated with CO(2) laser at an energy power of 1 or 2 W or with diode laser at 5 or 7 W for 15 s each and compared to enamel surfaces without treatment or topical fluoridated. Samples were examined by means of environmental scanning electron microscopy (ESEM). Surfaces of all enamel samples were then acid-etched, measuring the amount of fluoride deposited on the enamel by using a selective ion electrode. Other enamel surfaces selected under the same conditions were irradiated as described above, measuring the increase in pulp temperature with a thermocouple wire. Fluorination with CO(2) laser at 1 W and diode laser at 7 W produced a significantly greater fluoride uptake on enamel (89 ± 18 mg/l) and (77 ± 17 mg/l) versus topical fluoridation alone (58 ± 7 mg/l) and no treatment (20 ± 1 mg/l). Diode laser at 5 W produced a lesser alteration of the enamel surface compared to CO(2) laser at 1 W, but greater pulp safety was provided by CO(2) laser (ΔT° 1.60° ± 0.5) than by diode laser (ΔT° 3.16° ± 0.6). Diode laser at 7 W and CO(2) laser at 2 W both caused alterations on enamel surfaces, but great pulp safety was again obtained with CO(2) (ΔT° 4.44° ± 0.60) than with diode (ΔT° 5.25° ± 0.55). Our study demonstrates that CO(2) and diode laser irradiation of the enamel surface can both increase fluoride uptake; however, laser energy parameters must be carefully controlled in order to limit increases in pulpal temperature and alterations to the enamel surface.

Effect of fluorides from various restorative materials on remineralization of adjacent tooth: an in vitro study.

The aim of the study was to evaluate the extent of surface zone remineralization and the effect of fluoride at the inter-proximal adjacent tooth surface, using restorative materials FusionAlloy, Ketac-Fil and Heliomolar. Ninety extracted molar teeth were used of which 45 were placed in artificial caries for 10 weeks. The remaining 45 teeth were filled with the respective restorative materials, mounted with the artificial carious teeth in proximal contact with plaster and placed in artificial saliva for a period of 28 days. Finally, sectioning of artificially carious teeth was done mesio-distally and observed under the optical microscope and scanning electron microscope. Comparison among the groups was done by one-way analysis of variance [ANOVA] and Fischer's F test. Intercomparison between the groups was done by using Dunnett's t-test. Results obtained from transmitted electron microscopic and scanning electron microscopic observations were almost similar with the Ketac-Fil and Heliomolar showing better results in surface zone remineralization compared to FusionAlloy. Also, Ketac-Fil is a good material in releasing fluoride to remineralize enamel when compared to Heliomolar and FusionAlloy. Thus, it can be used mainly in class II cavity restorations of primary and permanent dentitions due to the potential ability of fluoride containing glass ionomer cements and composite resins to remineralize incipient carious lesions on adjacent teeth.

Comparison of in vitro fluoride uptake from whitening toothpastes and a conventional toothpaste in demineralised enamel.

Studies on the compatibility of abrasives and fluoride compounds deal exclusively with fluoride uptake and remineralization after storing the enamel specimens in a toothpaste-saliva mixture. The influence of brushing on the fluoride uptake when highly abrasive toothpastes are used has hardly been investigated so far. The aim of the present study was to investigate fluoride uptake in initially demineralised dental enamel after storage in, or brushing with, whitening toothpaste slurries, compared to a conventional toothpaste. For this purpose two widely available whitening toothpastes with ionically bound fluoride (sodium fluoride NaF), two with covalently-bound fluoride toothpastes (sodium monofluorophosphate, NaMFP) and a conventional amine fluoride toothpaste (AmF) were compared. The fluoride uptake after use of the AmF toothpaste was shown to be statistically significantly higher than that after application of the NaF toothpastes, which in turn was statistically significantly higher than the uptake resulting from NaMFP application. The fluoride uptake was slightly higher when the enamel samples were brushed with NaF toothpaste, rather than just stored in the respective toothpaste slurry. Brushing with highly abrasive toothpastes did not negatively influence fluoride uptake in demineralised dental enamel. The ionic form of the fluoride in toothpastes appears to be critical for increased fluoride uptake. The acidic components of the AmF toothpaste improved fluoride uptake compared to alkaline NaF toothpastes.

Evaluation of salivary fluoride retention from a new high fluoride mouthrinse.

OBJECTIVES: To evaluate salivary fluoride retention from a new high fluoride daily use mouthrinse over a 120 min period. METHODS: Sixteen subjects completed a randomised single-blind, four-treatment cross-over trial. Sensodyne® Pronamel® mouthrinse (A) contained 450 ppm fluoride; reference products were Colgate® Fluorigard® (B), Listerine® Total Care (C) and Listerine Softmint Sensation (D) containing 225, 100 and 0 ppm fluoride respectively. Salivary fluoride retention was monitored ex vivo after a single supervised use of test product (10 mL, 60 s). Samples were collected at 0, 1, 3, 5, 15, 30, 60 and 120 min post-rinse, generating fluoride clearance curves from which the area under the curve (AUC) was calculated. Differences in salivary fluoride concentrations for each product were analysed using ANCOVA at each time point using a 5% significance level, as well as lnAUC for the periods 0-120, 0-1, 1-15, 15-60 and 60-120 min. Pairwise comparisons between all treatment groups were performed. RESULTS: Salivary fluoride levels for A-C peaked immediately following use. Fluoride levels were statistically significantly higher for A versus B-D (p≤ 0.004), linear dose responses were apparent. AUC(0-120) was statistically significantly greater for A than for B (p = 0.035), C (p< 0.0001) and D (p< 0.0001). Post-hoc comparisons of lnAUC for the remaining time domains showed fluoride retention from A was statistically significantly greater versus B-D (p< 0.0001). CONCLUSIONS: Single-use treatment with the new mouthrinse containing 450 ppm fluoride resulted in statistically significantly higher salivary fluoride levels throughout the 120 min test period. Total fluoride retention (AUC(0-120)) was also statistically significantly greater versus comparator rinse treatments.