Anti-erosive effect of rinsing before or after toothbrushing with a Fluoride/Stannous Ions solution: an in situ investigation

Protecting primary teeth from dental erosion through bioactive glass

OBJECTIVES

The present study aimed to evaluate the effectiveness of bioactive glass (BAG) in preventing dental erosion in primary teeth.

METHODS

Enamel and dentin specimens (2 × 2 × 2 mm) were obtained from extracted primary teeth, which were randomly divided into the following groups based on the pretreatments (n = 12): DW (deionized water), NaF (2 % sodium fluoride), 2BAG (2 % BAG), 4BAG (4 % BAG), 6BAG (6 % BAG), and 8BAG (8 % BAG). The specimens were immersed in the respective solutions for 2 min and subjected to in vitro erosive challenges (4 × 5 min/d) for 5 d. The erosive enamel loss (EEL), erosive dentin loss (EDL), and the thickness of the demineralized organic matrix (DOM) were measured using a contact profilometer. The surface microhardness (SMH) was measured, and the percentage of SMH loss (%SMHL) was calculated. The surface morphology and mineral composition were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), respectively.

RESULTS

After the erosive challenges, the EEL, EDL, and%SMHL of the 2BAG, 4BAG, 6BAG, and 8BAG groups significantly reduced, with the greatest reduction was observed in the 6BAG (EEL: 6.5 ± 0.2 μm;%SMHL in enamel: 12.8 ± 2.6; EDL: 7.9 ± 0.3 μm; %SMHL in dentin: 22.1 ± 2.7) and 8BAG groups (EEL: 6.4 ± 0.4 μm;%SMHL in enamel: 11.0 ± 1.9; EDL: 7.8 ± 0.5 μm; %SMHL in dentin: 22.0 ± 2.5) (P < 0.05). With increasing BAG concentrations, the number of surface deposits containing Ca, P, and Si increased.

CONCLUSIONS

6BAG was the most effective for preventing dental erosion in primary teeth and showed a particularly strong potential for dentin erosion prevention.

CLINICAL SIGNIFICANCE

Bioactive glass, especially at a 6 % concentration, has proven effective in reducing erosive tooth wear and surface microhardness loss while also protecting demineralized organic matrix in primary dentin.

Toothpaste containing TiF4 and chitosan against erosive tooth wear in situ

OBJECTIVE

This study compared the protective effect of an experimental TiF4/Chitosan toothpaste with a commercial toothpaste on the prevention of erosive tooth wear (ETW) in situ.

METHODS

Fifteen subjects took part in this crossover and double-blind study, in which they wore a palatal appliance containing 4 bovine enamel and 4 dentin in 3 phases (5 days each). Half of the samples were subjected to erosive challenges (90 s in 0.1 % citric acid, pH 2.5, 4 times/day), and the other half to erosive plus abrasive challenges (15 s plus 45 s of contact, 2 times/day). The phases corresponded to the application of the different toothpastes: 1) TiF4 (1400 ppm F-) plus Chitosan, 2) Elmex®, Erosion Protection (1400 ppm F-, Chitosan), and 3) Placebo (negative control). Tooth wear was measured using contact profilometry (μm) and submitted to two-way RM ANOVA/Tukey test (p < 0.05).

RESULTS

No significant differences were detected between the experimental and commercial toothpastes, regardless of the challenge on both tissues. Both significantly reduce ETW compared to negative control (p < 0.0006). Tooth wear was increased by brushing only on eroded enamel (p < 0.01), but not on dentin (p = 0.6085). TiF4/Chitosan [erosion 2.98 ± 1.12 μm vs. erosion and abrasion 3.12 ± 1.33 μm] and Elmex® toothpastes [erosion 2.35 ± 0.93 μm vs. erosion and abrasion 2.98 ± 1.0 μm] minimized the impact of brushing compared to placebo on enamel [erosion 4.62 ± 1.48 μm vs. erosion and abrasion 5.15 ± 1.50 μm].

CONCLUSIONS

TiF4 plus chitosan toothpastes showed to be effective in minimizing the ETW as the commercial toothpaste is in situ.

CLINICAL RELEVANCE

The experimental toothpaste has similar effect against ETW compared to the commercial toothpaste. Considering the increased ETW prevalence worldwide, this result supports clinical trials and a possible application of this experimental anti-erosive toothpaste in the future.

Should We Wait to Brush Our Teeth? A Scoping Review Regarding Dental Caries and Erosive Tooth Wear

BACKGROUND

Tooth brushing is a universal recommendation. However, the recommendations related to the time of its execution are conflicting, especially when dealing with patients at risk of erosive tooth wear (ETW) or dental caries.

SUMMARY

Our objective was to summarize the evidence on the timing of brushing with fluoridated toothpaste in relation to ETW and cariogenic dietary challenges. We conducted a scoping review following the PRISMA-ScR checklist, using three databases searching for in vivo, in situ, or in vitro studies involving human teeth exposed to either a cariogenic or an erosive challenge. Only models including human saliva and fluoride were assessed. Data selection, extraction, and risk of bias analysis were done in duplicate and independently. From 1,545 identified studies, 17 (16 related to ETW and 1 to dental caries) were included. Most evidence (n = 10) supported that brushing with a fluoride-containing product does not increase ETW, independent of the moment of brushing. Delaying tooth brushing up to 1 h (n = 4) or individualized recommendations based on the patient's problem (n = 2) were less frequent. Only one study reported that brushing pre- or post-meal does not affect Streptococcus mutans counts. Most data were in situ (n = 13), and the overall study quality was judged as sufficient/low risk of bias.

KEY MESSAGES

Although the available evidence lacked robust clinical studies, tooth brushing using fluoridated products immediately after an erosive challenge does not increase the risk of ETW and can be recommended, which is in line with recommendations for dental caries prevention. Furthermore, we suggest updating the international guidelines to promote individualized recommendations based on risk factors to prevent either ETW or dental caries.

Topical Agents for Nonrestorative Management of Dental Erosion: A Narrative Review

A nonrestorative approach to the management of dental erosion is the foremost option: controlling dental erosion. The objectives of this study are to provide an overview and to summarise the effects and properties of topical anti-erosive agents as a nonrestorative treatment of dental erosion. A literature search was conducted on five databases of peer-reviewed literature—Cochrane Library, EMBASE, PubMed, Scopus and Web of Science—to recruit articles published between 1 January 2000 and 31 December 2021. The literature search identified 812 studies; 95 studies were included. Topical anti-erosive agents can be broadly categorised as fluorides, calcium phosphate-based agents, organic compounds and other anti-erosive agents. In the presence of saliva, fluorides promote the formation of fluorapatite on teeth through remineralisation. Calcium phosphate-based agents supply the necessary minerals that are lost due to the acid challenge of erosion. Some organic compounds and other anti-erosive agents prevent or control dental erosion by forming a protective layer on the tooth surface, by modifying salivary pellicle or by inhibiting the proteolytic activity of dentine collagenases. Topical anti-erosive agents are promising in managing dental erosion. However, current evidence shows inconsistent or limited results for supporting the use of these agents in clinical settings.

The protective effect of the experimental TiF4 and chitosan toothpaste on erosive tooth wear in vitro

This study evaluated the protective effect of TiF₄ and chitosan toothpaste on erosive tooth wear (ETW) in vitro. Enamel and dentin samples were randomly assigned to toothpastes (n = 12): (G1) TiF₄ (1400 ppm F⁻), (G2) 0.5% chitosan (75% deacetylation, 500 mPas), (G3) TiF₄ (1400 ppm F⁻) plus 0.5% chitosan (75% deacetylation, 500 mPas), (G4) Placebo, (G5) Erosion Protection (Elmex-GABA, 1400 ppm F⁻). Twelve samples were only eroded. All samples were submitted to erosive pH cycles and G1 to G5 to abrasive challenges using toothpastes’ slurries plus 45 s of treatment, for 7 days. The final profile was overlaid to the baseline one for the ETW calculation (µm). The data were subjected to Kruskal–Wallis/Dunn tests. TiF₄ toothpastes, regardless of the presence of chitosan, were able to significantly reduce ETW compared to placebo, while chitosan alone was similar to placebo for both tissues. The toothpastes containing TiF₄ were even superior to the commercial Elmex toothpaste on enamel, while they were similar on dentin; both were also significantly different from placebo for both tissues. TiF₄ and Elmex toothpastes minimized the impact of brushing on eroded surface. In conclusion, TiF₄ toothpastes, regardless the presence of chitosan, showed to be effective in minimizing ETW in vitro.

Obliterating potential of active products for dentin hypersensitivity treatment under an erosive challenge

OBJECTIVES

To compare the effect of 5 desensitizing agents on the hydraulic conductance (Lp) of dentin and to analyze its surface under a Laser Scanning Confocal Microscope (LSCM) before and after an erosive challenge.

METHODS

Lp was analyzed in the following sequence: in the presence of smear layer (pMin), after a 15-second acid etching (pMax), after treatment with a desensitizing agent (pTreat) and after a 1-minute erosive challenge (6% citric acid - pEro). Fifty 1.0 ± 0.2 mm-thick dentin disks were prepared from sound human third molars and were randomly distributed into 5 groups (n = 10): FG-Fluoride gel (control), SA-Sensiactive, PR-Sensitive Pro-Relief, NP-Desensibilize Nano-P and EV-Enamel Pro Varnish. Data were analyzed by two-way ANOVA and Tukey tests (α<0.05). Additional specimens were analyzed under a Laser Scanning Confocal Microscope (LSCM) and by Energy Dispersive X-ray Spectroscopy (EDS).

RESULTS

All materials reduced the Lp in some extent, except for FG and EV. After the erosive challenge, SA was the only material effectively able to keep the same Lp of the post-treatment phase, while the other products showed lower resistance upon an erosive challenge. Under the LSCM, the SA and NP materials were more effective to obliterate the opened dentin tubules and demonstrated higher resistance upon an erosive challenge. The EDS analysis evidenced levels of Ca, O, P, Si, Na and S.

CONCLUSIONS

Product containing potassium oxalate was the most effective in reducing Lp of dentin samples before and after an erosive challenge. Under a LSCM, products containing potassium oxalate or hydroxyapatite crystals seemed to be occluding the dentin tubules after an erosive challenge.