Polyphenols and Brazilian red propolis incorporated into a total-etching adhesive system help in maintaining bonding durability

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.

Effect of propolis added to single-bottle adhesives on water permeation through the hybrid layer

Water treeing and water droplets are observed within adhesive layers and on the hybridized surface after bonding sound dentin using single-bottle etch-and-rinse adhesives, indicating permeability of the hybrid layer to water. The aim of this study was to assess the efficacy of dentin sealing by adhesives containing propolis by quantifying the area of water transudation from dentinal tubules after dentin hybridization. Brazilian red propolis was added to experimental adhesive and Single Bond (3M/ESPE) adhesive; experimental adhesive and Single Bond without propolis were used as controls. Under simulated pulp pressure, two layers of adhesive were applied to etched human dentin discs. Three minutes after light-curing, the hybridized dentin surface was replicated, and epoxy resin replicas were created to obtain scanning electron microscope images. Data were evaluated using ANOVA and Tukey's test. Single Bond containing propolis significantly decreased water permeation through the hybrid layer compared with the control group. Three minutes after polymerization, the experimental adhesive without propolis had formed a permeable hybrid layer. The addition of Brazilian red propolis significantly reduced surface water on hybridized dentin in a concentration-dependent manner. Two-step etch-and-rinse adhesives containing propolis were effective in reducing water permeation through the hybridized dentin surface.

The in vitro assessment of rheological properties and dentin remineralization of saliva substitutes containing propolis and aloe vera extracts

Saliva substitutes with enhanced dentin remineralization properties were expected to help manage caries progression in patients with xerostomia. This in vitro study examined the rheological properties and remineralization action of experimental saliva substitutes containing propolis extract and aloe vera extract on demineralized dentin. Four experimental saliva substitutes were formulated with varying concentrations of propolis extract (P) and aloe vera extract (A) were prepared. A commercial saliva substitute (Biotene Oral Rinse) was used as a commercial comparison. The rheological properties and viscosity of these materials were measured using a strain-controlled rheometer (n = 3). The remineralizing actions of saliva substitutes on demineralized dentin after 2 weeks were determined using ATR-FTIR and SEM-EDX (n = 8). The results were expressed as a percentage increase in the mineral-to-matrix ratio. Biotene demonstrated a significantly higher viscosity (13.5 mPa·s) than experimental saliva substitutes (p<0.05). The addition of extracts increased the viscosity of the saliva substitutes from 4.7 mPa·s to 5.2 mPa·s. All formulations showed minimal shear thinning behavior, which was the viscoelastic properties of natural saliva. The formulation containing 5 wt% of propolis exhibited the highest increase in the median mineral-to-matrix ratio (25.48%). The SEM-EDX analysis revealed substantial mineral precipitation in demineralized dentin, especially in formulations with 5 wt% or 2.5 wt% of propolis. The effect of the aloe vera extract was minimal. The addition of propolis and aloe vera extracts increased the viscosity of saliva substitutes. the addition of propolis for 2.5 or 5 wt% to saliva substitutes increased mineral apatite precipitation and tubule occlusion. To conclude, the saliva substitute containing propolis extract demonstrated superior remineralizing actions compared with those containing only aloe vera extract.

The comparative evaluation of the effects of quercetin, α-tocopherol, and chlorhexidine dentin pretreatments on the durability of universal adhesives

OBJECTIVE

The aim of this study was to evaluate and compare the effects of chlorhexidine, quercetin, and α-tocopherol on the shear bond strength of universal adhesives in the short (24h) and long term (6 months).

MATERIAL AND METHODS

Ninety-six extracted sound molars were collected and divided randomly into four groups: control (no treatment), 2% chlorhexidine, 10% α-tocopherol, and 1% quercetin. The solutions were prepared and applied to the teeth for 60 s, followed by application of All-Bond universal adhesive and composite build-up. Half of the specimens in each group (n = 12) were tested for shear bond strength (SBS) after 24 h of storage and the other half were kept in distilled water for 6 months and then tested for shear bond strength. The shear bond strength test was performed and the failure modes were determined using a stereomicroscope. The data were analyzed using two-way analysis of variance and Tukey's post hoc tests with p ˂ .05 as the significance level.

RESULTS

The results of the two-way analysis of variance test showed that there was no significant difference in immediate SBS, and after 6 months, α-tocopherol had the lowest SBS in comparison to the control and CHX subgroups (p < .05). The t-test showed that the shear bond strength in the α-tocopherol and quercetin groups was significantly decreased after 6 months.

CONCLUSION

It can be concluded that the solutions used in this study had no adverse effect on immediate SBS. After 6 months, the CHX could preserve SBS in comparison to other groups.

Shiri MH, Sohrabniya F. Comparative evaluation of the postbleaching application of sodium ascorbate, alpha-tocopherol, and quercetin on shear bond strength of composite resin to enamel

OBJECTIVE

This study aimed to evaluate and compare the impacts of the postbleaching application of sodium ascorbate, alpha-tocopherol, and quercetin on the shear bond strength (SBS) of composite resin.

MATERIAL AND METHODS

60 extracted intact maxillary first premolars were collected and were randomly divided into five experimental groups as follows (n=12): Group A (negative control): no bleaching, Group B (positive control): bleaching with 40% hydrogen peroxide (HP), Group C: HP±10% sodium ascorbate for 10min, Group D: HP±10% alpha-tocopherol for 10min, and Group E: HP±1% quercetin for 10min. Composite bonding was done immediately after bleaching for Groups B-E and without any treatment for Group A. After being stored in distilled water at room temperature for 24h, all specimens were tested for SBS in the universal testing machine. One-way analysis of variance and Tukey's post-hoc test were used to analyze the SBS values of all groups.

RESULTS

The results showed that the bonding of composite to the unbleached group exhibited the highest mean value of SBS (22.68±2.91MPa). Among the antioxidant-treated groups, the highest SBS value was detected in quercetin-treated specimens (15.45±1.58MPa), which was significantly different from the positive control group (p<.05).

CONCLUSION

It could be concluded that 10% quercetin applied for 10min increased the bond strength to bleached enamel, but it was not able to reverse it completely.

Propolis in Oral Healthcare: Antibacterial Activity of a Composite Resin Enriched With Brazilian Red Propolis

The aim of this study was to obtain a Brazilian red propolis (BRP) enriched composite resin and to perform the characterization of its antibacterial activity, mechanical, and physical-chemical properties. Brazilian red propolis ethyl acetate extract (EABRP) was characterized by LC-ESI-Orbitrap-FTMS, UPLC-DAD, antibacterial activity, total flavonoids content, and radical scavenging capacity. BRP was incorporated to a commercial composite resin (RC) to obtain BRP enriched composite at 0.1, 0.15 and 0.25% (RP10, RP15 and RP25, respectively). The antibacterial activity RPs was evaluated against Streptococcus mutans by contact direct test and expressed by antibacterial ratio. The RPs were characterized as its cytotoxicity against 3T3 fibroblasts, flexural strength (FS), Knoop microhardness (KHN), post-cure depth (CD), degree of conversion (DC%), water sorption (Wsp), water solubility (Wsl), average roughness (Ra), and thermal analysis. Were identified 50 chemical compounds from BRP extract by LC-ESI-Orbitrap-FTMS. EABRP was bacteriostatic and bactericide at 125 and 500 μg/ml, respectively. The RP25 exhibited antibacterial ratio of 90.76% after 1 h of direct contact with S. mutans (p < 0.0001) while RC no showed significative antibacterial activity (p = 0.1865), both compared with cell control group. RPs and RC no showed cytotoxicity. RPs exhibited CD from 2.74 to 4.48 mm, DC% from 80.70 to 83.96%, Wsp from 17.15 to 21.67 μg/mm³, Wsl from 3.66 to 4.20 μg/mm³, Ra from 14.48 to 20.76 nm. RPs showed thermal resistance between 448–455°C. The results support that propolis can be used on development of modified composite resins that show antibacterial activity and that have compatible mechanical and physical-chemical properties to the indicate for composite resins.