Effect of sodium hexametaphosphate and quercetin, associated or not with fluoride, on dentin erosion in vitro

Effects of quercetin on mineralized dental tissues: A scoping review

OBJECTIVE

This scoping review (SR) aimed to investigate the impact of quercetin on mineralized dental tissues intended to be used in preventive and restorative dentistry.

METHODS

This SR was conducted following the PRISMA-ScR statement. A comprehensive search was performed across databases for articles published up to March 2024. Eligible studies included in vitro and in situ studies and evaluating the potential therapeutic effects of quercetin on dental enamel and dentin. Data were extracted, and synthesis of study findings was conducted.

RESULTS

Out of the 2322 records screened, 22 studies were included in the review. Quercetin, in solution or into dental materials increased the bond strength to enamel and dentin. Additionally, quercetin also enhanced the bond strength of enamel after bleaching. Co-administration of quercetin with fluoride prevented erosive wear and inhibited the proteolytic activity in dentin more effectively than either agent alone. Hardness and modulus of elasticity was higher in dentin treated with quercetin compared to placebo. Reduction of nanoleakage at the composite-dentin interface was reduced in the presence of quercetin as a solution or incorporated into dental adhesives.

CONCLUSIONS

Quercetin exhibits promising therapeutic effects on mineralized dental tissues, including remineralization and enhancement of bond strength. It shows potential as a multifunctional agent for improving the longevity and effectiveness of dental biomaterials, as well as in preventing erosion and dental caries. However, as these conclusions are largely drawn from lab-based (in vitro) studies, further research, including clinical trials, is needed to fully explore its therapeutic potential and applications in dentistry.

Low-fluoride gels supplemented with nano-sized sodium trimetaphosphate reduce dentin erosive wear in vitro

OBJECTIVE

The study assessed the effect of low-fluoride gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMP) on dentin erosive wear in vitro.

DESIGN

Bovine dentin blocks (n = 154) were selected by surface microhardness and randomly allocated into seven groups (n = 22/group), according to the gels: Placebo; 4500 ppm F (4500F); 9000 ppm F (9000F); 5% TMP microparticulate plus 4500F (5TMPm+4500F); 2.5% TMP nanoparticulate plus 4500 F (2.5TMPn+4500F); 5% TMP nanoparticulate plus 4500F (5TMPn+4500F); and 12,300 ppm F acid gel (APF). All blocks were treated only once for 60 s and cyclically eroded (ERO, citric acid, 4 × 90 s/day) or eroded and brushed (4 × 15 s/day, five strokes/s, ERO+ABR) over five days (each subgroup n = 11). Dentin wear and integrated hardness loss in depth (ΔKHN) were determined, and the data were submitted to two-way ANOVA, followed by Tukey's test, and Spearman's correlation (p < 0.05).

RESULTS

For ERO, all gels containing 4500F supplemented with TMP significantly reduced dentin wear compared with their counterpart without TMP, reaching values similar to 9000F. For ERO+ABR, 5TMPn+ 4500F gel led to significantly lower wear than all its counterparts, reaching values similar to 9000F and APF. As for ΔKHN, all gels containing TMP promoted superior protective effects compared with 4500F, reaching values similar to 9000F and APF under both challenges. A positive correlation between dentin wear and mineral content in depth was verified.

CONCLUSIONS

Gels containing 4500F supplemented with TMP significantly reduced dentin erosive wear compared with pure 4500F, with additional benefit from the use of nanoparticles.

Enhancing the inhibition of dental erosion and abrasion with quercetin-encapsulated hollow mesoporous silica nanocomposites

Introduction: Dental erosion and abrasion pose significant clinical challenges, often leading to exposed dentinal tubules and dentine demineralization. The aim of this study was to analyse the efficacy of quercetin-encapsulated hollow mesoporous silica nanocomposites (Q@HMSNs) on the prevention of dentine erosion and abrasion. Method: Q@HMSNs were synthesized, characterized, and evaluated for their biocompatibility. A total of 130 dentine specimens (2 mm × 2 mm × 2 mm) were prepared and randomly distributed into 5 treatment groups (n = 26): DW (deionized water, negative control), NaF (12.3 mg/mL sodium fluoride, positive control), Q (300 μg/mL quercetin), HMSN (5.0 mg/mL HMSNs), and Q@HMSN (5.0 mg/mL Q@HMSNs). All groups were submitted to in vitro erosive (4 cycles/d) and abrasive (2 cycles/d) challenges for 7 days. The specimens in the DW, NaF, and Q groups were immersed in the respective solutions for 2 min, while treatment was performed for 30 s in the HMSN and Q@HMSN groups. Subsequently, the specimens were subjected to additional daily erosion/abrasion cycles for another 7 days. The effects of the materials on dentinal tubule occlusion and demineralized organic matrix (DOM) preservation were examined by scanning electron microscopy (SEM). The penetration depth of rhodamine B fluorescein into the etched dentine was assessed using confocal laser scanning microscopy (CLSM). The erosive dentine loss (EDL) and release of type I collagen telopeptide (ICTP) were measured. The data were analysed by one-way analysis of variance (ANOVA) with post hoc Tukey's test (α = 0.05). Results: Q@HMSNs were successfully synthesized and showed minimal toxicity to human dental pulp stem cells (HDPSCs) and gingival fibroblasts (HGFs). Q@HMSNs effectively occluded the dentinal tubules, resulting in a thicker DOM in the Q@HMSN group. The CLSM images showed more superficial penetration in the HMSN and Q@HMSN groups than in the quercetin, NaF, and DW groups. The Q@HMSN group exhibited a significantly lower EDL and reduced ICTP levels compared to the other groups (p < 0.05). Conclusion: Q@HMSNs hold promise for inhibiting dentine erosion and abrasion by promoting tubule occlusion and DOM preservation.

Effects of the application timing of anti-erosive agents on dentin erosion

This in vitro study aimed to evaluate the effects of the application timing of anti-erosive agents on dentin erosion. Eighty dentin specimens with dimensions of 2 × 2 × 2 mm were prepared and randomly divided into 4 groups based on the treatment solutions: 1.23 × 104 μg/ml sodium fluoride (NaF), 120 μg/ml chlorhexidine (CHX), 300 μg/ml quercetin (QUE), and deionized water (DW, negative control). The specimens in each group were further divided into 2 subgroups according to the application timing of the treatment solutions (n = 10): before the erosive challenges (PRE) and after the erosive challenges (POST). All specimens were submitted to 4 daily erosive challenges for 5 d. For each erosive challenge, the specimens in the subgroup PRE were treated with the respective solutions for 2 min and then immersed in cola drinks for 5 min, while the specimens in the subgroup POST were immersed in cola drinks for 5 min followed by treatment with the respective solutions for 2 min. The erosive dentin loss (EDL) was measured using a contact profilometer, and the surface morphology of the dentin specimens was evaluated by scanning electron microscopy at the end of the experiment. The data were statistically analyzed using two-way analysis of variance (ANOVA) and Bonferroni's test (α = 0.05). Significantly less EDL was observed in the groups NaF, CHX, and QUE than in the group DW (all P < 0.001). Significantly lower EDL was observed in the groups CHX and QUE than in the group NaF (P = 0.001 and P < 0.001, respectively). For CHX, subgroup POST exhibited significantly less EDL than subgroup PRE (P < 0.001). Regarding QUE, subgroup PRE showed significantly less EDL than subgroup POST (P < 0.001). Furthermore, a relatively greater number of obliterated dentinal tubules was visible in the subgroup POST rather than in the subgroup PRE of the group CHX, while in the group QUE, narrower dentinal tubules were observed in the subgroup PRE than those in subgroup POST. In conclusion, CHX and QUE showed the best performance in controlling dentin erosion. CHX was more effective in reducing EDL when applied after erosive challenges, whereas QUE worked more effectively when used before erosive attacks. The application timing should be considered when evaluating the effects of anti-erosive agents because it may determine their effectiveness.