Effects of high-fluoride dentifrice (5,000-ppm) on caries-related plaque and salivary variables

Delivery of Low-Diluted Toothpaste during Brushing Improves Enamel Acid Resistance

Toothpaste viscosity decreases rapidly when diluted with saliva during brushing, potentially causing premature washout of high-risk caries areas and reducing the uptake of dental fluoride ions. However, no reports have examined the acid resistance of enamel from the perspective of the toothpaste's physical properties. This study aimed to elucidate the impact of toothpaste dilution on the acid resistance of the enamel, using bovine enamel as the subject. Five diluted toothpaste groups were created: a control group without toothpaste, and 100% (1.00×), 67% (1.50×), 50% (2.00×), and 25% (4.00×) dilution groups. Acid resistance was evaluated through pH cycling after toothpaste application. The results revealed a significant increase in substantial defects, compared to 67% (1.50×) at dilutions of 50% (2.00×) or higher, accompanied by a decrease in Vickers hardness. Moreover, the mineral loss increased with dilution, and a significant difference was observed between 67% (1.50×) and 50% (2.00×) (p < 0.01). This study revealed that the acid resistance of the enamel decreased when the dilution of toothpaste during brushing exceeded 67% (1.5×). Therefore, delivering toothpaste with a lower dilution to high-risk caries areas, including interproximal spaces and adjacent surfaces, could maintain a higher concentration of active ingredients in the toothpaste, thereby enhancing its medical effects.

Dental innovations which will influence the oral health care of baby boomers

From the widespread use of smartphones and tablets to the multitude of applications available, older adults are showing an interest in utilizing technology to maintain their independence and to improve their quality of life. As technology continues to advance and be incorporated into many day-to-day activities, the baby boom generation will see these changes affecting the way they access and utilize dental services. Innovative toothbrushes and chemotherapeutics are continuing to be developed and utilized by many older adults. Within the dental office, older adults are seeing greater application of technology in every day dental procedures. These include the use of teledentistry, artificial intelligence (AI), innovative restorative materials, digitization of fixed and removable prosthodontics, cone beam computed tomography (CBCT) scans to guide dental implant placement and endodontic procedures. There is also new technology to aid in cancer detection and shielding during cancer treatment. Improved communication between the medical and dental fields has become increasingly necessary to facilitate effective patient care and a few innovative healthcare systems have begun to consolidate these services. Overall, the baby boom generation will continue to see dental innovations that will change the way they experience everyday life and dental services.

Salivary fluoride bioavailability after use of high-fluoride dentifrices with different compositions: A short-term randomized clinical trial

OBJECTIVE

The objective of the study was to evaluate the kinetics of salivary F bioavailability after the use of high-fluoride dentifrices with different compositions and their amount of total soluble fluoride (TSF).

METHODS

A short-term clinical randomized trial was performed in which 15 adult participants were randomly allocated into three groups: 5000 ppm F-dentifrice, 5000 ppm F-dentifrice + TCP (tri-calcium phosphate) and 1450 ppm F-dentifrice. Unstimulated saliva was collected at different times: baseline (before toothbrushing), immediately after brushing/water rinsing and at 5, 15 and 30 min and 1, 2, 4, 8 and 12 h after brushing. The TSF in dentifrices and saliva samples was analysed using an ion-specific electrode. For statistical analysis, the paired t-test and Kruskal-Wallis were used with Dunn's post-test with a 95% confidence interval.

RESULTS

There was no significant difference between the declared TSF and that found in 5000 ppm F-dentifrice and 1450 ppm F-dentifrice (p ≥ 0.13); however, in the 5000 ppm F-dentifrice + TCP, approximately 500 ppm less TSF was observed (p = 0.0024). The area under the curve (AUC, μg F/ml min-1 ) of both high-fluoride dentifrices (321.7 ± 84.0 and 223.6 ± 55.1 for the one without and with TCP, respectively) was higher than the conventional one (89.97 ± 15.6) attesting a higher F-bioavailability (p = 0.04). Furthermore, they were able to provide F-salivary levels higher than the baseline for up to 2 h, while this time was 1 h for the 1450 ppm F-dentifrice (p ≤ 0.003).

CONCLUSION

Both high-fluoride dentifrices similarly increased the salivary-F bioavailability in comparison with 1450 ppm F-dentifrice, despite the lower TSF presented by the dentifrice containing TCP.

Comparison of interproximal delivery and flow characteristics by dentifrice dilution and application of prepared toothpaste delivery technique

In home care, the toothpaste technique, which can enhance the caries-preventive effect without changing the amount of dentifrice and fluoride ion concentration, is of great significance. This study aimed to construct a model and experimental system that reproduces the interdental part and to clarify the relationship between the change in dentifrice viscosity due to dilution and washout in the high-risk approximal area of caries. Additionally, the effectiveness of the toothpaste technique and appropriate devices for delivering dentifrice to the interdental area at a low dilution were investigated. Diluted toothpaste samples were prepared (: ×1.00, ×1.25, ×1.50, ×1.75, ×2.00, ×3.00, and ×4.00). An acrylic interproximal model was created for this experiment. The flow characteristics and viscosity by dentifrice dilution were measured. In the case of low dilution of 57% (1.75×) or more, it was shown that the dentifrice in the high-risk area may be washed out early because of the decrease in viscosity, and the caries-preventive effect may be reduced. It was also suggested that to keep the dentifrice in the interdental area for 120 s at the end of brushing, a dilution must be devised to a concentration of at least 50% (2.00×). The prepared toothpaste delivery (PTD) method of delivering dentifrice to the interdental area while maintaining it at a low dilution is an effective toothpaste technique in terms of dentifrice dilution and viscosity. The use of finger brushes in the PTD method could increase the efficiency of dentifrice delivery.

Comparative Evaluation of Chair-Side Saliva Tests According to Current Dental Status in Adult Patient

Background: this cross-sectional study evaluated the correlation of commercial chair-side saliva tests with caries status in adults. Methods: teeth in 87 adults (20–40 years old) were clinically examined for carious lesions according to International Caries Detection and Assessment System (ICDAS) criteria. The Decayed-Missing-Filling-Tooth (DMFT) and Decayed-Missing-Filling-Surface (DMFS) indexes at D1 (lesions 1–6 according to ICDAS criteria) and D3 (lesions 4–6 according to ICDAS criteria threshold and the number of active lesions, according to the Lesion Activity Assessment (LAA)) criteria were measured. The saliva parameters measured by chair-side tests were stimulated and non-stimulated saliva flow rate, saliva consistency, saliva pH, saliva buffer capacity, and lactic acid production. The statistical analyses performed were Student t-test and Mann–Whitney U test at a = 0.05 significant level. Results: the low resting saliva pH was related to a high value of DMFT (D1) index (p = 0.007). Conclusions: among the saliva parameters measured, the values of low resting pH are associated with increased DMFT at threshold D1. None of the chair-side available saliva tests evaluated can accurately underline the tooth carious status.

Dose-Response Effect of Fluoride Dentifrices on De-/Remineralization of Root Dentine in situ

The present study aimed to evaluate the effect of fluoride (F) dentifrice with different F concentrations on root dentine de-/remineralization. Ten healthy volunteers took part in this randomized, double-blinded, cross-over, and split-mouth in situ experimental study. During 4 phases of 7 days, they wore a palatal appliance containing 4 bovine dentine blocks (2 sound and 2 with caries) of 4 × 4 × 2 mm. Treatments were performed with silica-based dentifrices containing 0, 700, 1,300, and 5,000 µg F/g (F as NaF). To provide a cariogenic challenge, a 20% sucrose solution was dripped 3 and 8 times daily on the carious-like and sound blocks, respectively. After each experimental phase, the percentage of surface hardness loss (%SHL) or recovery (%SHR) was calculated and the fluoride concentration in the biofilm was determined. The statistical analysis was performed using ANOVA and the Tukey post hoc test with p at 5%. The relationship between variables was analyzed by linear regression. The results showed a lower %SHL when 5,000 µg F/g dentifrice was used but without a statistically significant difference from the conventional one (1,300 µg F/g). Regarding remineralization and F in biofilms, the high-fluoride dentifrice was expressively superior in mineral replacement on the surface and in the F concentration in the biofilms, respectively, compared to the other 3 products (p < 0.05). Also, a significant linear fit between mineral loss/gain, F in biofilms, and fluoride concentration in the dentifrices could be observed. In conclusion, a dose-response F effect was observed, and the high-fluoride dentifrice was effective in enhancing root dentine remineralization in this short-term in situ study.

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.

Effect of high-fluoride dentifrice and bracket bonding composite material on enamel demineralization in situ

OBJECTIVE

This in situ study evaluated the effect of high-fluoride dentifrice (5000 μg F^-/g) and fluoride-containing bonding composite resin on enamel demineralization adjacent to orthodontic brackets.

METHODS

Ten volunteers wore palatal appliances containing bovine enamel blocks with metallic brackets bonded with fluoride-free or fluoride-containing composite resin. During three phases of 14 days each, three dentifrices with different fluoride concentrations (0, 1100, and 5000 μg F^-/g) were tested. The cariogenic challenge consisted of 20% sucrose solution dripped 8x/day onto the dental blocks. At the end of each phase, biofilm formed was collected for fluoride analysis. Cross section hardness was performed in enamel blocks, and the lesion area was calculated. Data were analyzed by two-way ANOVA followed by Tukey post hoc test (α = 5%).

RESULTS

The only signicant factor for all the variables under study was the dentifrice. Smaller lesion area and higher fluoride concentration on biofilm were found in 5000 μg F^-/g group, irrespective of bonding composite resin (p < 0.001). Neither bracket-bonding composite resin nor the interaction between the factors was statistically significant (p > 0.05) for all the variables.

CONCLUSION

High-fluoride dentifrice is effective in reducing demineralization on enamel adjacent to orthodontic brackets, while the fluoride-containing bonding composite resin does not influence it.

CLINICAL SIGNIFICANCE

Since high-fluoride dentifrice was able to reduce demineralization adjacent to brackets, it can be an option to caries management in orthodontics patients.

Oral microflora in preschool children attending a fluoride varnish program: a cross-sectional study

Background

To compare the oral microflora in preschool children attending a fluoride varnish program with a reference group receiving a standard oral health program without fluoride varnish applications. A second aim was to relate the microbial composition to the caries prevalence.

Methods

Five hundred seven 3-year-old children were enrolled from a cohort of 3403 preschool children taking part in a community based oral health project. Two hundred sixty-three of them had attended caries-preventive program with semi-annual applications of a fluoride varnish since the age of 1 year (test group) while 237 had received standard preventive care (reference group). Oral samples were collected with a sterile swab and analysed with checkerboard DNA-DNA hybridization using 12 pre-determined bacterial probes. Caries and background data were collected from clinical examinations and questionnaires.

Results

Gram-positive streptococci (S. intermedius, S. salivarius, S. oralis) were most frequently detected and displayed the highest counts in both groups. There were no significant differences between the groups concerning prevalence of any of the selected bacterial strains except for S. oralis that occurred less frequently in the reference group. In children with caries, V. parvula were significantly more common (p < 0.05) while strains of Lactobacillus, Bifidobacterium and Neisseria were more prevalent among the caries-free children (p < 0.05).

Conclusions

A 2-year community program with semi-annual fluoride varnish applications did not seem to significantly influence the oral microflora in preschool children.

Trial registration

www.controlled-trials.com (ISRCTN35086887) 20131216 ‘retrospectively registered’.

Evaluation of Chair-Side Assays in High Microbiological Caries-Risk Subjects

The aim of this study was to evaluate the commercial chair-side assays Saliva-Check Mutans and ClinproTM Cario L-PopTM in high microbiological caries-risk dental students compared with conventional semi-quantitative colony counting culture-based technique as the reference method. Saliva samples from 93 subjects of both sexes aged 18-26 years were seeded (Köhler and Bratthall method) on plates containing SB-20M culture medium method and 12 subjects with high caries risk were selected. These 12 individuals were subjected to determination of caries risk using two commercial rapid detection chair-side assays (Saliva-Check Mutans and ClinproTM Cario L-PopTM) according to the manufacturers' instructions. The results were analyzed by the Kappa correlation test using SAS statistical software. There was a perfect agreement (Kappa=1) among the three caries risk evaluation methods - chair-side assays and semi-quantitative CFU count (control) - in all subjects. The results suggest that the commercial chair-side assays evaluated in this study may be practical and useful to identify high microbiological caries-risk subjects.