Comparative evaluation of the effectiveness of desensitizing agents in dentine tubule occlusion using scanning electron microscopy

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.

Effects of Propolis-Based Herbal Toothpaste on Dentine Hypersensitivity

INTRODUCTION

The objective of this in vitro study was to compare the effectiveness of a propolis-based herbal toothpaste with 5% sodium fluoride varnishin obstructing human dentinal tubules; Scanning electron microscopy was utilised to obtain quantitative and qulitative data on tubular obstruction.

METHODS

Thirty-nine extracted human premolar teeth were collected. The cementum layer was removed using a water-cooled diamond bur and the smear layer using ethylenediaminetetraacetic acid (EDTA) 17%. Then, the samples were randomly divided into 3 groups (n = 13 each), as follows: group 1: dentin discs exposed to the propolis-based herbal toothpaste (Herbex); group 2: dentin discs exposed to 5% sodium fluoride varnish; and group 3: control. Then, all discs were observed and imaged in 4 non-overlapping fields by an electron microscope at 2000× magnification. The topography and number of open, closed, and semi-closed tubules were counted in all images. The data were analysed using Kruskal-Wallis test, Mann-Whitney U test, and Friedman test. The statistical analysis was performed with SPSS statistic 22.0 software, with a significance level of α = 0.05.

RESULTS

In pairwise comparisons of the groups considering the percentage of open, closed, and semi-closed tubules, the difference was not statistically significant between the 5% sodium fluoride varnish and propolis groups in the closed and semi-closed tubules, but it was statistically significant with the control group. Additionally, the percentage of open tubules in the propolis-based herbal toothpaste group was significantly lower than in the 5% sodium fluoride varnish and control group.

CONCLUSIONS

Both propolis-based herbal toothpaste and 5% sodium fluoride varnish is effective in blocking human dentin tubules to various extents.

Comparative Evaluation of the Effectiveness of Three Commercially Available Desensitizing Mouthwash on Dentinal Tubule Occlusion: An In Vitro Scanning Electron Microscopic Study

Aim

To compare and evaluate the effectiveness of three commercially available desensitizing mouthwashes on dentinal tubule occlusion in vitro using a scanning electron microscope (SEM).

Materials and Methods

Twenty-seven premolar maxillary teeth were collected and cleaned to remove debris and tissue using an ultrasonic scaler. Enamel was removed with the help of a high-speed plain cut tungsten carbide fissure bur under continuous water spray. Dentinal discs measuring 5 mm × 5 mm × 3 mm were prepared from the coronal region of the extracted teeth using a double-sided carborundum disc and straight micromotor handpiece. Using carborundum paper, the discs were polished and washed with distilled water. The discs were etched using 37% phosphoric acid to remove any smear layer that was caused by the grinding process and to simulate dentinal hypersensitivity by opening the dentinal tubules. The specimens were again washed and stored in distilled water until use. Samples were then randomly allocated into Group A: calcium sodium phosphosilicate mouthwash, Group B: potassium nitrate mouthwash, and Group C: dipotassium oxalate monohydrate mouthwash. The specimens were immersed in a test tube filled with the respective mouthwash and vigorously shaken for 60 s for simulating the natural mouth rinsing action. This procedure was repeated for 7 days, twice daily. To compare and assess the proportion of dentinal tubule occlusion, all the samples were processed and examined under an SEM.

Results

The efficacy of the mouthwash on the obliteration of dentinal tubules was compared using the Kruskal-Walis analysis of variance test followed by the post hoc Mann-Whitney U test for pairwise comparison. Group A showed completely occluded tubules in 5 (55.6) and mostly occluded tubules in 4 (44.4). Group B showed mostly occluded in 4 samples (44.4) and partially occluded in 5 samples (55.6) and Group C showed completely occluded tubules in 3 samples (33.3) and mostly occluded tubules in 6 samples (66.7). A P value of 0.05 or less is regarded as statistically significant. *P ≤ 0.05 is statistically significant. Between Group A and Group B as well as between Group B and Group C, there was a statistically significant difference. However, a statistically significant difference between Group A and Group C does not exist.

Conclusion

The calcium sodium phosphosilicate group was shown to have the most occlusion of the dentinal tubule, followed by dipotassium oxalate monohydrate and potassium nitrate group.

In vitro evaluation of remineralizing agents on dentinal tubule occlusion: A scanning electron microscopic study

Context

Over the years, numerous treatment modalities have been researched for the management of dentinal hypersensitivity. A recent remineralizing agent containing a phase of amorphous calcium phosphate combined with fluoride has shown the ability to rapidly convert into biomimetic hydroxyapatite. This potential can be utilized in occluding the dentinal tubules for the treatment of hypersensitivity.

Aims

The present study aims to compare the effectiveness of biomimetic hydroxyapatite-based tooth mousse and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) tooth mousse as desensitizing agents on dentinal tubule occlusion.

Materials and Methods

The in vitro study design involved 30 prepared dentin specimens that were divided into three groups: Group A: negative control, Group B: CPP-ACP tooth mousse (GC tooth mousse™), and Group C: fluoride-doped amorphous calcium phosphate (F-ACP) tooth mousse (Curasept Biosmalto Denti Sensibili Tooth Mousse). The specimens were observed under a scanning electron microscope (SEM) and an attached energy-dispersive X-ray (EDX) spectroscopy apparatus after 1 week.

Statistical Analysis

The data were analyzed using Kruskal-Wallis test and post hoc Mann-Whitney test for intragroup and intergroup analysis, respectively.

Results

The SEM analysis of the F-ACP group showed statistically greater percentage of tubule occlusion (40.21%) compared to the CPP-ACP group (38.15%). EDX analysis of both F-ACP and CPP-ACP groups revealed calcium, phosphorus, carbon, oxygen, and silica with an additional fluoride element in the F-ACP group.

Conclusions

In the present study, both remineralizing agents were able to occlude the dentinal tubules. Among the two, the F-ACP tooth mousse showed greater tubule occlusion, and therefore, appears promising as an upcoming remineralizing agent in the management of dentinal hypersensitivity.

Effects of Arginine-calcium carbonate pretreatment on the remineralizing and bonding performance of phosphorylated dentin

OBJECTIVES

To evaluate the effects of Arginine-calcium carbonate (Arg-CaCO₃) paste treatment of phosphorylated dentin on remineralizing and bonding performance during direct and indirect restorations under pulpal pressure.

METHODS

Under simulated pulpal pressure, dentin of healthy third molars were abraded and acid etched for 15s, then randomly divided into 4 groups: negative control group; Arg-CaCO₃ group (1min); 2.5% Sodium trimetaphosphate (STMP) group (3min); S-A group, 2.5% STMP + Arg-CaCO₃. After 24h, remineralization and dentin tubular occlusion were assessed by Attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), Micro-Raman spectroscopy, Vickers hardness, Field-emission scanning electron microscope (FESEM) and Energy X-ray dispersive spectrometer (EDS). The liquid environment was the simulated body fluid (SBF) permeated from dentin tubules due to pulpal pressure. Stick specimens prepared with self-etch dentin adhesive were tested for microtensile bond strength (μTBS) and interfacial silver nanoleakage on both immediate direct restoration and indirect restoration with a 7-day temporary period. Data were analyzed by the Kruskal-Wallis test, Mann-Whitney test, Welch ANOVA or one-way ANOVA and Tukey post hoc test (p < 0.05).

RESULTS

The pretreatment of 2.5% STMP with Arg-CaCO₃ significantly increased relative mineral content by ATR-FTIR, Raman and FESEM-EDS, simultaneously enhancing dentin tubular occlusion (%) and mechanical property to the most considerable extent. Furthermore, the pretreatment significantly promoted the μTBS of indirect restoration and reduced nanoleakage after 7 days.

CONCLUSIONS

The application of Arg-CaCO₃ paste on phosphorylated dentin could improve intra- and extra-tubular mineralization and the stability of adhesion interface.

CLINICAL RELEVANCE

Without exceeding the amount of conventional tooth preparation, combining 2.5% STMP with Arg-CaCO₃ paste before the self-etch bonding system might be a promising clinical strategy to relieve dentin hypersensitivity and strengthen bonding performance efficiently and conveniently.

Comparative evaluation of diode laser alone and in combination with desensitizing toothpaste in occlusion of dentinal tubules - A SEM study

Background

In regular dental practice, dentinal hypersensitivity is a common oral condition affecting the adult population. Although a variety of treatment procedures are available, there is no single method that proved to be potent in eliminating dentine hypersensitivity and providing patients with complete relief. Hence the present study performed to estimate the occlusion of dentinal tubules using a diode laser alone and in combination with various desensitizing toothpaste, using the scanning electron microscope.

Materials and methods

This in-vitro study consisted of five groups wherein cervical cavities were prepared on the extracted teeth followed by the application of 17% EDTA. The cavities were then treated with Novamin toothpaste, pro-arginine toothpaste, diode laser, and in combinations respectively. Then SEM analysis was done and the results obtained were statistically analyzed using tukey's multiple post hoc analysis for intra and inter group comparisons.

Results

The groups which were treated with a combination of diode laser and the desensitizing agent showed statistically significant (P < 0.05) better dentinal tubule occlusion than other groups.

Conclusion

The use of a diode laser has an added benefit in treating dentinal tubule occlusion when compared to desensitizing kinds of toothpaste.

Three-dimensional visualization of dentine occlusion based on FIB-SEM tomography

The occlusion of dentinal tubules has become a rapid and effective method for treating dentin hypersensitivity. Accurate evaluation of dentin occlusion is critical to illustrate the efficacy of oral care products and to optimize dental therapy in the clinics, which is limited by the conventional two-dimensional (2-D) characterization methods. Here, we demonstrate the visualization of the dentin occlusion via three-dimensional (3-D) characterization using a focused ion beam-scanning electron microscopy (FIB-SEM) tomography. Using the "Slice and View" approach, the material used for occluding dentin tubules is imaged with a very high-resolution voxel (10 nm × 10 nm × 20 nm) from 2-D SEM images and then reconstructed into a 3-D volume, which presents the mode of action of toothpaste for treating dentin hypersensitivity. Meanwhile, quantitative analysis of the depth of occlusion is successfully obtained. This work validates the feasibility of FIB-SEM tomography in the analysis of dentin occlusion within the complicated networks of dentine tubules at the nanoscale, and provides a novel approach to facilitate the research and development of oral care products.

Strontium Carbonate and Strontium-Substituted Calcium Carbonate Nanoparticles Form Protective Deposits on Dentin Surface and Enhance Human Dental Pulp Stem Cells Mineralization

Strontium acetate is applied for dental hypersensitivity treatment; however, the use of strontium carbonates for this purpose has not been described. The use of Sr-carbonate nanoparticles takes advantage of both the benefits of strontium on dentin mineralization and the abrasive properties of carbonates. Here in, we aimed to synthesize strontium carbonate and strontium-substituted calcium carbonate nanoparticles and test them as potential compounds in active dentifrices for treating dental hypersensitivity. For this, SrCO₃, Sr_0.5Ca_0.5CO₃, and CaCO₃ nanoparticles were precipitated using Na₂CO₃, SrCl₂, and/or CaCl₂ as precursors. Their morphology and crystallinity were evaluated by electron microscopy (SEM) and X-ray diffraction, respectively. The nanoparticles were added to a poly (vinyl alcohol) gel and used to brush dentin surfaces isolated from human third molars. Dentin chemical composition before and after brushing was investigated by infrared spectroscopy (FTIR) and X-ray dispersive energy spectroscopy. Dentin tubule morphology, obliteration, and resistance of the coatings to acid attack were investigated by SEM and EDS. The cytotoxicity and ability of the particles to trigger the mineralization of hDPSCs in vitro were studied. Dentin brushed with the nanoparticles was coated by a mineral layer that was also able to penetrate the tubules, while CaCO₃ remained as individual particles on the surface. FTIR bands related to carbonate groups were intensified after brushing with either SrCO₃ or Sr_0.5Ca_0.5CO₃. The shift of the phosphate-related FTIR band to a lower wavenumber indicated that strontium replaced calcium on the dentin structure after treatment. The coating promoted by SrCO₃ or Sr_0.5Ca_0.5CO₃ resisted the acid attack, while calcium and phosphorus were removed from the top of the dentin surface. The nanoparticles were not toxic to hDPSCs and elicited mineralization of the cells, as revealed by increased mineral nodule formation and enhanced expression of COL1, ALP, and RUNX2. Adding Sr_0.5Ca_0.5CO₃ as an active ingredient in dentifrices formulations may be commercially advantageous since this compound combines the well-known abrasive properties of calcium carbonate with the mineralization ability of strontium, while the final cost remains between the cost of CaCO₃ and SrCO₃. The novel Sr_0.5Ca_0.5CO₃ nanoparticles might emerge as an alternative for the treatment of dental hypersensitivity.

In vitro evaluation of Sensi-IP®: A soluble and mineralizing sensitivity solution

OBJECTIVES

Sensi-IP®OG (SIP-OG) and Sensi-IP®FF (SIP-FF) are soluble bioactive glasses developed to treat dentin hypersensitivity and promote remineralization. Evaluation of their therapeutic potential to reduce dentin hypersensitivity and recover enamel strength was evaluated using standardized in vitro assessments based on simulated use.

METHODS

To assess dentin occlusion a visual occlusion methodology was employed. Dentin discs were subjected to twice-daily simulated brushing (for 5 days) using 0.67 g of toothpaste for 10 s. Simple prototype toothpastes containing SIP-OG and SIP-FF were compared to commercially available controls: Colgate® Sensitive Pro-Relief (CPR) and Sensodyne® Repair and Protect with NovaMin® (SRP). Samples were stored in artificial saliva between treatments. All samples were assessed at baseline and subsequent to each treatment and were scored on a 5-point categorical scale for occlusion. For enamel surface effects, test articles of SIP-OG, SIP-FF, and SIP-FF with NaF were compared to a positive (with NaF) and a negative (no NaF) control paste. Enamel samples were subjected to a pH cycling regime, providing exposure to the toothpaste slurry (i.e., 2 parts deionized water to 1 part toothpaste), mineralizing solution, and demineralizing solution over 5 days of simulated use. Samples were stored overnight in mineralizing solution. Samples were evaluated for fluoride uptake and changes to surface microhardness.

RESULTS

Visual occlusion scores (1 fully occluded to 5 unoccluded) were 2.6, 3.8, 4.4 and 4.0 after 1 day of simulated use for SIP-OG, SIP-FF with NaF, Colgate® Sensitive Pro-Relief and Sensodyne® Repair and Protect, respectively, decreasing to 1.0, 1.8, 3.1 and 3.9 after 5 days of application. SIP-OG provided superior occlusion at the significance level of p ≤ 0.05 at 1, 2, 3, 4, and 5 days. SIP-FF with NaF provided superior occlusion at the significance level of p ≤ 0.05 at 2, 4, and 5 days. Fluoride uptake ranged from 9.0 μg/cm² for SIP-OG to 12.4 μg/cm² for SIP-FF with NaF. Surface microhardness after acid cycling allowed recovery of 59 % of surface microhardness after treatment with SIP-OG or SIP-FF with NaF. SIP-OG achieved significant surface microhardness recovery versus SIP-FF alone, a NaF control paste, and a fluoride free control paste at the significance level of p ≤ 0.05. SIP-FF with NaF achieved surface microhardness recovery versus SIP-FF alone, a NaF control paste, and a fluoride free control paste at the significance level of p ≤ 0.05.

CONCLUSIONS

Superior occlusion of dentin tubules was observed with both novel additives compared to commercially available toothpastes. A build-up effect with increasing occlusion was noted with repeated application for both novel additives and ascribed to mineralization effects, as supported by surface microhardness recovery on initial enamel lesions.

Efficacy of a calcium-phosphate/fluoride varnish and ionomeric sealant on cervical dentin hypersensitivity: A randomized, double-blind, placebo-controlled clinical study

BACKGROUND

Dentin hypersensitivity (DH) is a common problem in the population that can have a significant impact on the quality of life of those who suffer from the condition.

OBJECTIVES

Compare the efficacy of two treatments for DH: Ca/PO₄ ^- /F^- varnish (Clinpro White Varnish) and ionomeric sealant (IS) (Clinpro XT Varnish) with a placebo.

METHODS

Participants (121) with at least one tooth with visual analogue scale (VAS) score of 4 and above were randomly and blindly allocated to the groups. Treatments were performed by a trained researcher. DH was evaluated by another blind researcher after the treatment and after 1 week, 4 weeks, 3 months and 6 months. After 4 weeks, placebo received the DH treatment with IS; thus, the participants were not assessed after 3 and 6 months. Primary outcome was DH reduction after 4 weeks. Differences in VAS scores in the other time intervals and entire values of VAS were considered secondary outcomes. Comparisons were made among the groups (α = 0.05).

RESULTS

IS showed the highest VAS value difference between baseline and 4 weeks (mean ± SD: 3.7 ± 2.2), differing significantly from placebo (2.3 ± 1.7) and Ca/PO4/F^- varnish (2.6 ± 2.0). Ca/PO4^- /F^- varnish did not differ from placebo. In all time intervals, VAS values of all groups were significantly lower than the baseline value, without differences among groups. For the long-term differences in VAS values (3 and 6 months), the IS exhibited significantly higher values than Ca/PO4^- /F^- varnish.

CONCLUSIONS

The IS was the most efficacious product for reducing DH, whereas Ca/PO4^- /F^- varnish did not differ from placebo. Registered in ClinicalTrials.gov (NCT04591444).

Evaluation of the effects of different remineralisation agents on initial enamel lesions by scanning electron microscope and energy-distributed X-ray analysis

BACKGROUND

This study compared the ability of four remineralization agents to restore demineralised enamel lesions in permanent human incisors.

METHODS

In total, 40 teeth were included in the study. Two samples were obtained from each tooth. The 80 samples were divided into 10 groups (n = 8 per group). The right halves of the teeth were controls solely subjected to demineralisation and stored in artificial saliva for the duration of the experiment. The left halves of the teeth were remineralised using a 5% NaF-containing fluoride varnish (GC MI varnish; GC Corp.), a toothpaste containing casein phosphopeptide and amorphous calcium (GC tooth mousse; GC Corp.), a water-soluble remineralisation paste containing fluoride, hydroxyapatite, xylitol (Remin Pro; Voco), and ROCS remineralising gel containing Ca, magnesium(Mg) and phosphate (P). After 21 days of remineralisation, scanning electron microscopy and energy-dispersive X-ray (EDX) assessments were performed, and the results were analysed using one-way analysis of variance.

RESULTS

EDX analysis showed that the ROCS medical remineralising gel had the lowest Ca/P ratio among the groups (P = .04). Compared with the control groups, the Remin Pro and ROCS medical remineralising gel treatments produced significantly higher Ca/P ratios (P = .014 and P = .025). These results were statistically significant, and P-value <.05 was accepted for statistical significance.

CONCLUSIONS

The group treated with a fluoride-free, xylitol-containing ROCS medical remineralising gel had the lowest Ca/P ratio. Compared with the control groups, Remin Pro and ROCS remineralising gel appeared effective for repairing initial enamel lesions.

Treatment of Gingival Recession: When and How?

Gingival recession is a common finding in daily clinical practice. Several issues may be associated with the apical shift of the gingival margin such as dentine hypersensitivity, root caries, non-carious cervical lesions (NCCLs), and compromised aesthetics. The first step in an effective management and prevention program is to identify susceptibility factors and modifiable conditions associated with gingival recession. Non-surgical treatment options for gingival recession defects include establishment of optimal plaque control, removal of overhanging subgingival restorations, behaviour change interventions, and use of desensitising agents. In cases where a surgical approach is indicated, coronally advanced flap and tunnelling procedures combined with a connective tissue graft are considered the most predictable treatment options for single and multiple recession defects. If there is a contraindication for harvesting a connective tissue graft from the palate or the patient wants to avoid a donor site surgery, adjunctive use of acellular dermal matrices, collagen matrices, and/or enamel matrix derivatives can be a valuable treatment alternative. For gingival recession defects associated with NCCLs a combined restorative-surgical approach can provide favourable clinical outcomes. If a patient refuses a surgical intervention or there are other contraindications for an invasive approach, gingival conditions should be maintained with preventive measures. This paper gives a concise review on when and how to treat gingival recession defects.

Effect of natural primer associated to bioactive glass-ceramic on adhesive/dentin interface

OBJECTIVES

This study evaluated the effect of propolis associated with Biosilicate on the bond strength (BS) and gelatinolytic activity at the adhesive/dentin interface.

METHODS

Occlusal cavities were prepared in 320 human molars. Half of them were submitted to cariogenic challenge. All the teeth were separated into eight groups (n = 20): Control - Adhesive System (Single Bond Universal, 3 MESPE); CHX - 0.12 % Chlorhexidine; Bio - 10 % Biosilicate; P16 - Propolis with low levels of polyphenols; P45 - Propolis with high levels of polyphenols; CHX Bio - CHX + Bio; P16 Bio - P16+Bio; P45 Bio - P45+Bio. The adhesive was applied (self-etch mode) after treatments. Restorations (Filtek Z350, 3 MESPE) were performed and samples sectioned into sticks, separated and stored in distilled water at 37 °C for 24 h, 6 months and 1 year. Microtensile BS (0.5 mm/min) was tested and analyzed (2-way ANOVA, Bonferroni's Test, p < .05 and Weibull analysis). Fracture patterns (VH-M100, Keyence) and adhesive interfaces (SEM, EVO-MA10, ZEISS and TEM, JEM-1010, JEOL) were observed; and biodegradation and in situ zymography performed.

RESULTS

P16 presented the highest BS values on sound dentin after 6 months. In caries-affected dentin (CAD), the association of treatments promoted the highest BS after 24 h. Sound dentin obtained significantly higher Weibull modulus than CAD. SEM displayed resin tags in P16, P45 and association of treatments. TEM showed good interaction between adhesive and dentin. According to the in situ zymography and biodegradation assay all natural primers reduced the gelatinolytic activity. P45 presented the lowest biodegradation and enzymatic activity.

CONCLUSIONS

Propolis and the association of treatments promoted the highest bond strength results and preserved the dentin. All the experimental groups exhibited low gelatinolytic activity.

CLINICAL SIGNIFICANCE

Propolis and the association of treatments with Biosilicate could preserve the dentin substrate and improve the longevity of composite restorations.

Involvement of substance P, osteopontin and satellite glial cells on photobiomodulation-induced antinociceptive effect in an experimental model of dentin hypersensitivity

The aim of this work was to investigate the involvement of substance P (SP), osteopontin (OPN), and satellite glial cells (SGC) on photobiomodulation-induced (PBM) antinociceptive effect in an experimental model of dentin hypersensitivity (DH). Rats ingested isotonic drink (ID, pH 2.87) for 45 consecutive days and after this period received PBM irradiation at λ660 nm or λ808 nm (1 J, 3.5 J/cm², 100 mW, 10 s, 0.028 cm², continuous wave, 3 consecutive daily sessions), and were evaluated for nociceptive behavior 24, 48, 72 h, and 14 days after laser treatments. ID ingestion induced an increase on thermal sensitivity of DH characteristics in rats that was completely reversed by PBM treatment at both 660 and 808 nm. Immunohistochemical analysis revealed increased SP expression at both dentin-pulp complex (DPC) and trigeminal ganglia (TG) of DH-rats which did not occur in PBM groups by PBM treatment. Also, the increase of glial fibrillary acidic protein (GFAP) observed in the TG of DH-rats was also reversed by PBM treatment. Finally, PBM at both 660 and 808 nm increased OPN expression in the dentin-pulp complex of DH-rats after 14 days of PBM treatment. All in all, this data demonstrates that PBM reverses nociception in a DH experimental model by inhibiting neurogenic inflammation and inducing a regenerative response.

Bioactive glass versus Arginine dentifrices on the reduction of dentin permeability and acid tolerance

Objectives

To compare the efficacy of calcium sodium phosphosilicate (CSPS) and arginine dentifrices on dentin permeability and acid tolerance.

Material and Methods

Sixty dentin discs were randomly assigned into 3 groups, then brushed for 1 min with CSPS, arginine, or fluoride (control) dentifrices. To test acid tolerance, each disc was soaked in 6% citric acid for 1 min. Dentin permeability was measured before, following brushing, and acid challenge. Ten discs per group were similarly treated and evaluated for tubule occlusion following a single dentifrice application, while other five discs per group were employed in an acid tolerance assay.

Results

The percentage reduction in dentin permeability was 39.26%, 32.27%, and 21.71% in the arginine, CSPS, and control groups, respectively. The differences in dentin permeability reduction between the arginine and CSPS groups following brushing and acid challenge were not significant (p = 0.398 and p = 0.211, respectively). The arginine dentifrice demonstrated a significant reduction in permeability compared with the control (p = 0.011). In addition, the occlusion exhibited by the arginine and CSPS dentifrices was more resistant to acid challenge compared with that of the control (p < 0.001). From SEM analysis, dentinal tubule occlusion was observed after a single application in all groups. Some open dentinal tubules were detected in the test groups, while almost all of the orifices were open in the fluoride group following acid challenge.

Conclusions

There is no significant difference between arginine and CSPS dentifrices in reducing dentin permeability following a single application and acid challenge. Following acid challenge, the reduced permeability generated by arginine and CSPS was more stable compared with the fluoride dentifrice.

Evidence-Based Studies and Perspectives of the Use of Brazilian Green and Red Propolis in Dentistry

This review analyzes the evidence and perspectives of dental use of the green and red propolis produced in Brazil by Apis mellifera L. Multiple applications of propolis were found considering its antibacterial, antifungal, anti-inflammatory, immunomodulatory, antiviral, and healing properties. Its therapeutic effects are mainly due to the presence of alcohols, aldehydes, aliphatic acids, aliphatic esters, amino acids, aromatic acids, aromatic esters, flavonoids, hydrocarbyl esters, ethers, fatty acids, ketones, terpenes, steroids, and sugars. Propolis has been mainly used in dentistry in the composition of dentifrices and mouthwashes. Studies have also demonstrated promising use against dentin hypersensitivity, root canal treatment, Candida albicans, and other microorganisms. Overall review of the literature presented here demonstrated that both Brazilian green and red propolis are effective for the problems of multiple etiologies that affect the oral cavity in different dental specialties.

Comparison of the effectiveness of three different desensitizing toothpastes in reducing dentin hypersensitivity: A 4-week clinical study

Aim:

To compare the effectiveness of three different desensitizing toothpastes containing potassium salt, natural ingredients, and 8% arginine in reducing dentin hypersensitivity (DH).

Materials and Methods:

A 4-week study was conducted on 45 adult patients suffering from hypersensitivity associated with cervical abrasion of two or more teeth anterior to the molars. Patients were divided into three toothpaste groups as follows: Group I: potassium salt, Group II: herbal desensitizing paste containing natural ingredients, and Group III: 8% arginine. Using tactile stimulus and air stimulus, the sensitivity scores were recorded using Visual Analog Scale (VAS) at baseline, immediately after application, after 1 week, after 2 weeks, and after 4 weeks.

Statistical Analysis:

One-way ANOVA test and post hoc Tukey's test were used, and P ≤ 0.05 was considered statistically significant.

Results:

Group III showed significantly better reduction in DH at all time intervals when compared with Group I. Group III was significantly better than Group II at 1, 2, and 4 weeks.

Conclusion:

Desensitizing toothpaste containing 8% arginine was found to be the most effective in the reduction of DH after a single application up to a period of 4 weeks followed by herbal desensitizing toothpaste and potassium salt-containing toothpaste.

Associative Protocol for Dentin Hypersensitivity Using Nd:YAG Laser and Desensitizing Agent in Teeth with Molar-Incisor Hypomineralization

Objective: The aim of this article was to describe and discuss a clinical case in which the Nd:YAG laser and a desensitizing agent were associated in a protocol for dentin hypersensitivity (DH) in teeth with molar-incisor hypomineralization (MIH). Background data: DH is a common condition among the population, being one of the main reasons for patients to seek for a dental treatment. MIH can be considered a condition that induces DH. Methods: The patient was referred for evaluation, complaining of hypersensitivity during eating or drinking cold foods. Clinical evaluation revealed the presence of MIH on the first lower molars. Aiming to treat DH, two strategies for dentin desensitization were associated: the use of a high-power laser (Nd:YAG laser, 1.064 nm; Lares Research), with a 300 μm quartz optical fiber, 1 W of power, 100 mJ of energy, 10 Hz of repetition rate, and 85 J/cm² of energy density, followed by the application of two layers of a desensitizing agent (Gluma Desensitizer). Results: DH was evaluated immediately, after 1 week and after 1 month of the treatment. Clinical outcomes were satisfactory, confirming the efficacy and considerable durability of the protocol used for the reduction of DH originated from MIH. Conclusions: The association of Nd:YAG laser and a desensitizing agent for controlling DH was effective, showing to be an interesting protocol.

Influence of the Extended Use of Desensitizing Toothpastes on Dentin Bonding, Microhardness and Roughness

The aim of this study was to evaluate the influence of an extended use of desensitizing toothpastes (DTs) on dentin bonding, microhardness and roughness. One hundred and twenty bovine incisor teeth were randomly divided into four groups: G1, distilled water (WATER); G2, Colgate Total 12 (CT12); G3, Colgate Sensitive Pro-Relief (CSPR); and G4, Sensodyne Repair ?αμπ; Protect (SRP). Dentin surfaces were etched with 17% EDTA and 2 years of simulated tooth brushing (20,000 cycles) was performed on their surfaces. Knoop microhardness, surface roughness and scanning electron microscopy (SEM) were performed before and after the simulated tooth brushing. For microshear bonding test, a 2-step self-etching adhesive system (Clearfil SE Bond) was used and 0.8 mm diameter composite resin (Filtek Z350 XT) cylinders were built. Microshear test was performed with an orthodontic wire and with a crosshead speed of 0.5 mm/min. The data were analyzed for: 1) bond strength (one-way ANOVA), 2) microhardness intra-group (Student's test) and inter-group (one-way ANOVA/Tukey's test) comparisons, 3) roughness intra-group (Student's test/Wilcoxon's test) and inter-group (Kruskal-Wallis/Student-Newman-Keuls test) comparisons. The extended use of both dentifrices (conventional and for sensitive teeth) did not affect the bond strength and produced a significant increase in microhardness and roughness of the dentin, except for the microhardness of the SRP group. The simulated tooth brushing technique with water produced an increase in roughness, without reducing significantly the dentin microhardness.

Mechanical and aesthetics compatibility of Brazilian red propolis micellar nanocomposite as a cavity cleaning agent

BACKGROUND

Propolis is a natural substance produced by bees and is known to have antimicrobial activity. Our aim was to evaluate the antimicrobial effect of micellar nanocomposites loaded with an ethyl acetate extract of Brazilian red propolis as a cavity cleaning agent and its influence on the color and microtensile bond strength (μTBS) of the dentin/resin interface.

METHODS

An ultra-performance liquid chromatography coupled with a diode array detector (UPLC-DAD) assay was used to determine the flavonoids and isoflavones present in an ethyl acetate extract of Brazilian red propolis (EARP) and micellar nanocomposites loaded with EARP (MNRP). The antimicrobial activity of EARP and MNRP was tested against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. One of the following experimental treatments was applied to etched dentin (phosphoric acid, 15 s): 5 μL of MNRP (RP3, 0.3%; RP6, 0.6%; or RP1, 1.0% w/v), placebo, and 2% chlorhexidine digluconate. Single Bond adhesive (3 M/ESPE) was applied and a 4-mm-thick resin crown (Z350XT, 3 M/ESPE) was built up. After 24 h, the teeth were sectioned into sticks for the μTBS test and scanning electron microscopy. Spectrophotometry according to the CIE L*a*b* chromatic space was used to evaluate the color. Data were analyzed using one-way ANOVA and the Tukey test or Kruskal-Wallis test and the same test for pairwise comparisons between the means (P < 0.05).

RESULTS

The UPLC-DAD assay identified the flavonoids liquiritigenin, pinobanksin, pinocembrin, and isoliquiritigenin and the isoflavonoids daidzein, formononetin, and biochanin A in the EARP and micellar nanocomposites. EARP and MNRP presented antimicrobial activity against the cariogenic bacteria Streptococcus mutans and Lactobacillus acidophilus, and for Candida albicans. ΔE values varied from 2.31 to 3.67 (P = 0.457). The mean μTBS for RP1 was significantly lower than for the other groups (P < 0.001). Dentin treated with RP1 showed the shortest resin tags followed by RP6 and RP3.

CONCLUSIONS

The EARP and (MNRP) showed antimicrobial activity for the main agents causing dental caries (Streptococcus mutans and Lactobacillus acidophilus) and for Candida albicans. MNRP at concentrations of 0.3 and 0.6% used as a cavity cleaner do not compromise the aesthetics or μTBS of the dentin/resin interface.

Non-surgical management of tooth hypersensitivity

Tooth sensitivity is a common complaint of patients in dental practices. Studies have demonstrated dentinal hypersensitivity to affect 10-30% of the population. There are various potential causes of tooth sensitivity and a variety of available treatment options. This narrative review will discuss the possible aetiology of this condition, as well as the treatment modalities available. A tailor-made treatment plan that starts with the most non-invasive treatment options and escalates only when those options have proven insufficient in alleviating symptoms should be provided for each patient. Only after all non- and less-invasive methods have failed to reduce the symptoms should more invasive treatment options, such as root-coverage, be considered.

Ability of three desensitizing agents in dentinal tubule obliteration and durability: An in vitro study

Aim:

The purpose of this study was to evaluate the effectiveness of three desensitizing agents on dentinal tubule obliteration and their durability in use on the dentinal tubules.

Materials and Methods:

Sixty specimens were obtained from 30 extracted sound human maxillary first premolars. Each tooth was mesiodistally sectioned to obtain 30 buccal and 30 lingual surfaces, and enamel was removed in order to simulate hypersensitive dentin. Specimens were divided into four groups with 15 specimens each. Group 1 samples were immersed in artificial saliva, Group 2 samples were coated with Vivasens, Group 3 samples were coated with VOCO Admira Protect, and Group 4 samples were coated with Neo Active Apatite suspension. These specimens were examined under scanning electron microscope (SEM) to find out the occluding ability of the respective products. The specimens were brushed to find out their durability for 1 week and 1 month and were examined under SEM.

Statistical Analysis:

The results were statistically analyzed by analysis of variance (ANOVA) and Tukey's test.

Results:

Group 1 differed significantly from the Vivasens, Admira, and Neo Active Apatite groups at 5% level of significance (P < 0.05). The Vivasens group differed significantly from the Admira and Neo Active Apatite groups at 5% level of significance (P < 0.05).

Conclusion:

The Ormocer-based Admira Protect showed the best results.