Fluoride Concentration from Dental Sealants

Evaluation of Antibacterial Activity of a Bioactive Restorative Material Versus a Glass-Ionomer Cement on Streptococcus Mutans: In-Vitro Study

BACKGROUND

Dental caries management consists of both preventive and restorative approaches. Pediatric dentists can rely on many techniques and materials to restore decayed teeth, but a high failure rate is still observed, mainly due to secondary caries. New restorative bioactive materials combine the mechanical and aesthetic characteristics of resinous materials with the capability to remineralize and the antimicrobial properties of glass ionomers, thus counteracting the occurrence of secondary caries. The aim of this study was to assess the antimicrobial activity against Streptococcus mutans of a bioactive restorative material (ACTIVA™ BioActive-Restorative™-Pulpdent©) and a glass ionomer cement with silver particles added (Ketac™ Silver-3M©), using agar diffusion assay.

METHODS

Each material was formed into disks of 4 mm in diameter, and four discs of each material were placed on nine agar plates. The analysis was repeated seven times.

RESULTS

Both materials showed statistically significant growth inhibition properties against S. mutans (p < 0.05). The difference in the effectiveness of the two materials was not statistically significant.

CONCLUSION

Both ACTIVA™ and Ketac™ Silver can be recommended since both are similarly effective against S. mutans. However ACTIVA™, given its bioactivity and better aesthetics and mechanical properties compared to GICs, may provide better clinical performance.

An Analytical Protocol for the Differentiation and the Potentiometric Determination of Fluorine-Containing Fractions in Bovine Milk

Free fluoride ions are effective in combating caries in children, and their supplementation in milk has been widely used worldwide for this purpose. Furthermore, it is known that ionic fluoride added to milk is distributed among its components, but little is known about their quantitative relationships. This is likely due to the absence of an analytical protocol aimed at differentiating and quantifying the most important forms of fluorine present in milk. For the first time, a comprehensive protocol made up of six potentiometric methods devoted to quantifying the most important fractions of fluorine in milk (i.e., the free inorganic fluoride, the inorganic bonded fluorine, the caseins-bonded fluorine, the whey-bonded fluorine, the lipid-bonded fluorine, and the total fluorine) has been developed and tested on real samples. Four of the six methods of the procedure are original, and all have been validated in terms of limit of detection and quantification, precision, and trueness. The data obtained show that 9% of all fluorine was in ionic form, while 66.3% of total fluorine was bound to proteins and lipids, therefore unavailable for human absorption. Beyond applications in dental research, this protocol could be extended also to other foods, or used in environmental monitoring.

Fluoride Release of Fresh and Aged Glass Ionomer Cements after Recharging with High-Fluoride Dentifrice

Objective

This study aimed to evaluate F release from GICs before and after recharging with F-dentifrices and after aging process.

Methods

Fifteen specimens of GICs (conventional, resin modified, and high viscosity) and composite resin were stored individually in a polystyrene tube containing 2 ml of deionized water (DW), with water replacement every 24 hours. After 15 days, the specimens were treated with a dentifrice suspension (1 : 3 by volume) containing 0 μg F/g (n = 5), 1,100 μg F/g (n = 5), or 5,000 μg F/g (n = 5). After 3 min, the specimens were rinsed and replaced in new tubes with 2 ml of DW. This procedure was performed 2x/day for 2 days. The readings were taken on days 1, 5, 10, and 15 before and after the treatments. A second experiment was performed, using the same specimens of the previous study that were submitted to an aging process (specimens were kept in 2 ml of DW, remaining at 37°C for 36 weeks). Readings using specific electrode for F detection were taken on days 1, 5, 10, and 15 after treatment of the samples as described above. Data were analyzed by ANOVA and Tukey's test with α fixed at 5%.

Results

It was observed that the highest release of F for all the GICs occurred on the first day after the treatments, especially when using a high-fluoride dentifrice, with decreasing release over time. Also, although aged GICs still recharge with F treatments, the amount of F released was lower than fresh materials.

Conclusion

GICs present a high F recharge and release capacity, especially in the first 24 hours and after the treatment with a high-fluoride dentifrice, even after material aging.

Effectiveness of Resin-Based Sealants with and without Fluoride Placed in a High Caries Risk Population: Multicentric 2-Year Randomized Clinical Trial

A split-mouth randomized clinical trial was carried out to assess the effectiveness of sealants in preventing carious ICDAS (International Caries Detection and Assessment System) 3–6 lesions within a 2-year follow-up. We evaluated the effectiveness of 2 types of resin-based sealants, with and without fluoride, their retention rates, and the caries risk factors related to their outcomes. The study included 663 tooth pairs in 400 children (aged 5–15 years) considered to be at high individual caries risk (ICR) and presenting permanent molars free of caries or affected by ICDAS 1–2 lesions. In the first randomization, molars were either randomized to the treatment group receiving a dental sealant or the control group (nontreatment), and in the second randomization the sealant material to be used in the intervention group was selected. Uni- and multivariate Cox proportional hazard models were employed. At the 2-year follow-up, 483 tooth pairs were assessed: sealed molars had 83% (adjusted HR = 0.17; 95% CI: 0.15–0.20) less risk of developing ICDAS 3–6 lesions than molars without sealant. The magnitude of the protective effect was lower among teeth with ICDAS 1–2 lesions or with occlusal deep fissures than without. If the total retention rate of sealants was 70% at 2 years, sealant loss was not associated with the risk of caries (HR = 1.29, 95% CI: 0.92–1.79, p = 0.14). Sealants allow the prevention of new ICDAS 3–6 lesions or progression of noncavitated carious lesions in children at high ICR, and the effect of the sealant was similar regardless of whether it contained fluoride or not.

Effect of Fluoridated Sealants on Adjacent Tooth Surfaces: A 30-mo Randomized Clinical Trial

A double-blind randomized clinical trial was performed in 6- to 7-yr-old schoolchildren to evaluate, in a 30-mo period, whether the caries increment on the distal surface of the second primary molars adjacent to permanent first molars sealed with fluoride release compounds would be lower with respect to those adjacent to permanent first molars sealed with a nonfluoridated sealant. In sum, 2,776 subjects were enrolled and randomly divided into 3 groups receiving sealants on sound first molars: high-viscosity glass ionomer cement (GIC group); resin-based sealant with fluoride (fluoride-RB group); and a resin-based sealant without fluoride (RB group). Caries (D1 - D3 level) was recorded on the distal surface of the second primary molar, considered the unit of analysis including only sound surfaces at the baseline. At baseline, no differences in caries prevalence were recorded in the 3 groups regarding the considered surfaces. At follow-up, the prevalence of an affected unit of analysis was statistically lower (p = .03) in the GIC and fluoride-RB groups (p = .04). In the GIC group, fewer new caries were observed in the unit of analysis respect to the other 2 groups. Incidence rate ratios (IRRs) were 0.70 (95% confidence interval: 0.50, 0.86; p < .01) for GIC vs. RB and 0.79 (95% confidence interval: 0.67, 0.89; p = .005) for fluoride-RB vs. RB [Corrected]. Caries incidence was significantly associated with low socioeconomic status (IRR = 1.18; 95% confidence interval: 1.10, 1.42; p = .05). Dental sealant high-viscosity GIC and fluoride-RB demonstrated protection against dental caries, and there was evidence that these materials afforded additional protection for the tooth nearest to the sealed tooth (clinical trial registration NCT01588210).