Dentinal Tubule Occlusion Research Articles

Impact of Various Desensitizing Agents on Occlusion of Dentinal Tubules: A Scanning Electron Microscopic Study

The aim of the present study was to compare the capacity of three dissimilar commercially accessible desensitizing products for the occlusion of dentinal tubules using a scanning electron microscope (SEM). The nondiseased human mandibular premolar teeth, ninety in number, were amassed for this study. The blocks subsequently made were subjected to polishing using abrasive paper to facilitate dentinal surface exposure. The samples were randomly allocated to one of the following three groups: Group I, samples to be treated with Admira Protect; Group II, samples to be treated with MI paste, Group III, samples to be treated with Remin Pro. Photomicrograph of every sample was taken to evaluate the occlusion of the dentin tubule under 2000× magnification of the SEM. MI paste exhibited the greatest dentin tubular occlusion with a value of 2.746 ± 0.530 followed by Admira Protect (3.498 ± 0.202) and Remin Pro (4.594 ± 0.364) in that order. Amid the various desensitizing materials used, statistically significant differences (p <0.001) were noted. Within the confines of the limitations of the present research, following a comparative assessment of the three desensitizing materials used, it can be concluded that all of them were efficient in sealing off the dentin tubules in spite of differing chemical constitutions and techniques of application. When compared with the agents, Admira Protect and Remin Pro, MI paste exhibited the maximum occluding capacity of the dentinal tubules. A short, sharp shooting pain characterizes the frequent problem of dentin hypersensitivity (DH). Sealing off the open dentin tubules, thereby reducing dentinal permeability, is a known method in the treatment of DH. As several agents exist to reduce DH, the best commercially marketed product for decreasing this condition by occluding the tubules should be identified by the clinicians.

Effect of Novel Bioactive Glass-Containing Dentin Adhesive on the Permeability of Demineralized Dentin.

This study aimed to evaluate the effect of a novel bioactive glass (BAG)-containing dentin adhesive on the permeability of demineralized dentin. Bioactive glass (85% SiO2, 15% CaO) was fabricated using the sol-gel process, and two experimental dentin adhesives were prepared with 3 wt% silica (silica-containing dentin adhesive; SCA) or BAG (BAG-containing dentin adhesive; BCA). Micro-tensile bond strength (μTBS) test, fracture mode analysis, field-emission scanning electron microscopy (FE-SEM) analysis of adhesive and demineralized dentin, real-time dentinal fluid flow (DFF) rate measurement, and Raman confocal microscopy were performed to compare SCA and BCA. There was no difference in μTBS between the SCA and BCA (p > 0.05). Multiple precipitates were evident on the surface of the BCA, and partial occlusion of dentinal tubules was observed in FE-SEM of BCA-approximated dentin. The DFF rate was reduced by 50.10% after BCA approximation and increased by 6.54% after SCA approximation. Raman confocal spectroscopy revealed an increased intensity of the hydroxyapatite (HA) peak on the dentin surface after BCA application. The novel BAG-containing dentin adhesive showed the potential of both reducing dentin permeability and dentin remineralization.

Calcium-Doped Silica Nanoparticles Mixed with Phosphate-Doped Silica Nanoparticles for Rapid and Stable Occlusion of Dentin Tubules

Long-term occlusion of dentin tubules is a challenge due to the relatively easy removal of the inorganic or organic materials used to occlude them by abrasion or erosion of the treated surface. To overcome this problem, the current work aimed to develop a combination nanomaterial system to enable rapid and stable occlusion of dentin tubules. A large-sized calcium-doped silica nanomaterial (187 nm, Ca-DMSN-L) and a small-sized phosphate-doped silica nanomaterial (74 nm, P-DMSN-S) were fabricated and mixed (denoted as L + S; dendritic mesoporous silica nanomaterial denoted as DMSN). Rapid and dense occlusion of dentin tubules was achieved by the topical application of this combination nanomaterial paste to the dentin surface. Fast hydroxyapatite growth was induced by contact with artificial saliva over three repeated 1 min applications. The material occluding the dentin tubules demonstrated strong resistance to acid and abrasion. In comparison, a large-sized phosphate-doped silica nanomaterial (187 nm, P-DMSN-L) was also fabricated and mixed with Ca-DMSN-L to form the L + L material. It also achieved rapid occlusion but showed less resistance to acid and abrasion than the L + S material. The design of using large and small combo material (L + S) has considerable potential for the treatment of dentin hypersensitivity by rapidly causing occlusion of dentin tubules.

An Eggshell-Based Toothpaste as a Cost-Effective Treatment of Dentin Hypersensitivity.

Objectives This study aimed to test the efficacy of two experimentally produced eggshell-based toothpastes on dentinal tubules occlusion. Materials and Methods Two experimental eggshell toothpastes, based on natural ingredients, with or without titanium dioxide nanoparticles (TNPs) were produced and coded “TNPs eggshell toothpaste [TNPsESTP]” or “eggshell toothpaste [ESTP],” respectively. Mid-coronal dentin discs, from 28 human extracted molar teeth, etched with 37% phosphoric acid for 60 seconds to simulate the hypersensitive dentin, were randomly divided into four groups—G1: no treatment (negative control), G2: ESTP treated, G3: TNPsESTP treated, and G4: Biorepair treated (positive control). All treated discs were brushed for 2 weeks and 1 month using a toothbrush simulator at 40 mm/s. Dentinal tubules occlusion was studied using a cross-polarization optical coherence tomography (CP-OCT) and scanning electron microscopy (SEM). Statistical Analysis Unpaired t -test was conducted using GraphPad software (San Diego, California, United States). Continuous variables were expressed as means ± standard deviation and p < 0.05 was considered statistically significant. Results From CP-OCT, a marked increase in surface reflectivity of dentin was observed after brushing with tested toothpastes. ESTP and NPsESTP showed higher or comparable grayscale values than Biorepair indicating increase in surface density of dentin. From SEM, at 2 weeks, ESTP showed comparable number of completely occluded dentinal tubules to Biorepair. TNPsESTP showed significantly lower numbers of CODT than Biorepair. At 1 month, the number of CODT was difficult to count for all treated groups. Both ESTP and TNPsESTP showed significantly higher numbers of partially occluded dentinal tubules than Biorepair. Conclusion ESTP or TNPsESTP could offer a cost-effective substitute for the treatment of dentin hypersensitivity.

Biomineralization of Dental Tissues Treated with Silver Diamine Fluoride

Silver diamine fluoride (SDF) is a dental biomaterial used to arrest dental caries. To better understand SDF’s mechanism of action, we examined the localization of silver within the tissues of SDF-treated teeth. Carious primary teeth fixed within 2 min of SDF application (SDF-minutes, n = 3), at 3 wk after SDF application in vivo (SDF-weeks, n = 4), and at 2 y after multiple SDF applications in vivo (SDF-multiple, n = 1) were investigated in this study. Carious primary teeth without SDF application (no-SDF, n = 3) served as controls. Mineral density and structural analyses were performed via micro–X-ray computed tomography and scanning electron microscopy. Elemental analyses were performed through X-ray fluorescence microprobe and energy-dispersive X-ray spectroscopic techniques. SDF-treated teeth revealed higher X-ray–attenuated surface and subsurface regions within carious lesions, and similar regions were not present in no-SDF teeth. Regions of higher mineral density correlated with regions of silver abundance in SDF-treated teeth. The SDF penetration depth was approximated to 0.5 ± 0.02 mm and 0.6 ± 0.05 mm (mean ± SD) for SDF-minutes and SDF-weeks specimens, respectively. A higher percentage of dentin tubular occlusion by silver or calcium phosphate particles was observed in primary teeth treated with SDF-weeks as compared with SDF-minutes. Elemental analysis also revealed zinc abundance in carious lesions and around the pulp chamber. SDF-weeks teeth had significantly increased tertiary dentin than SDF-minutes and no-SDF teeth. These results suggest that SDF treatment on primary teeth affected by caries promotes pathologic biomineralization by altering their physicochemical properties, occluding dentin tubules, and increasing tertiary dentin volume. These seemingly serendipitous effects collectively contribute to the cariostatic activity of SDF.

Evaluating the antibacterial effect of synthesized herbal toothpastes and their efficacy for dentine tubule occlusion: Scanning electron microscopy and energy-dispersive X-ray spectroscopy analysis.

The tubule occlusion of two newly developed herbal toothpastes was examined. They were prepared based on the mixture of pomegranate peel and Equisetum arvense extracts with strontium acetate. The antimicrobial activity of pomegranate peel and E. arvense were determined using minimum inhibitory concentration (MIC). Then, 30 mid-coronal dentin discs from the human third molars were etched for 30 s with the lemon juice (pH=2.4). The specimens divided into the three groups. While the control group had 6 specimens, Groups 1 and 2 were including 12 specimens. Group 1 brushed with toothpaste containing 10% strontium acetate and 5% hydroalcoholic extracts of pomegranate peel, and Group 2 brushed with 5% strontium acetate, 5% hydroalcoholic extracts of E. arvense, and 5% hydroalcoholic extracts of pomegranate peel. Brushing was simulated for 6months with 2N loading. Then, 50% of discs in each group were immersed in lemon juice for 1min. Moreover, specimens in control group were brushed with distilled water. Finally, all 30 discs were analyzed using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDXS). The occluded dentin tubules were counted and statistically evaluated. It was found that the number of open dentin tubules decreases significantly after brushing with both tested toothpastes compared with control group (p < .001). Moreover, a significant difference was observed between two toothpastes before and after acid immersion process (p < .001). The SEM micrographs confirmed the dentin tubule occlusion of both herbal dentifrices. Besides, EDXS analysis approved the strontium and silica presence on the dentin tubules for the toothpaste which was based on E. arvense.

The Amelogenin-Derived Peptide TVH-19 Promotes Dentinal Tubule Occlusion and Mineralization.

In this study, the amelogenin-derived peptide, TVH-19, which has been confirmed to promote mineralization, was evaluated to derive its potential to induce dentinal tubule occlusion. The binding capability of fluorescein isothiocyanate (FITC)-labeled TVH-19 to the demineralized dentin surface was analyzed by confocal laser scanning microscopy (CLSM). Additionally, the sealing function of the peptide was studied through the remineralization of demineralized dentin in vitro. The adsorption results showed that TVH-19 could bind to the hydroxyapatite and demineralized dentin surfaces, especially to periodontal dentin. Scanning electron microscopy analysis further revealed that TVH-19 created mineral precipitates. The plugging rate in the TVH-19 group was higher than that in the PBS group. Moreover, energy-dispersive X-ray spectroscopy (EDX) results indicated that the calcium/phosphorus (Ca/P) ratio of the new minerals induced by TVH-19 was close to that of the hydroxyapatite. Attenuated total internal reflection-Fourier transform infrared (ATR-FTIR) spectrometry and X-ray diffraction (XRD) results indicated that the hydroxyapatite crystals formed via remineralization elongated the axial growth and closely resembled the natural dentin components. These findings indicate that TVH-19 can effectively promote dentin sealing by binding to the periodontal dentin, promoting mineral deposition, and reducing the space between the dentin tubules.

Duration of dentin tubule occlusion by the calcium phosphate precipitation method: An in vivo study in beagle dogs.

The aim of the present study was to assess the duration of dentin tubule occlusion by the calcium phosphate precipitation (CPP) method in the vital teeth of beagle dogs. Vital teeth were treated using the CPP method, potassium oxalate, or a bonding agent (Liner bond II) after cavity preparation and acid etching. The dentin tubules of all groups, except for the bonding agent, opened more widely with time in the absence of plaque control. Dentin tubules treated with the CPP method were open and no precipitate remained in the absence of plaque control. Differences were observed in dentin tubule occlusion when plaque control was achieved by daily tooth brushing. The majority of dentin tubules were occluded with an apatitic precipitate seven days after the CPP method with plaque control. The present results demonstrated that the CPP method is useful with proper plaque control.

Study on Occluding Dentinal Tubules with a Nanosilver-Loaded Silica System In Vitro.

The effects of most clinical treatments for dentin hypersensitivity are not long-lasting. To overcome the defects, the mesoporous silica nanoparticles and silver nanoparticles entered the field of oral materials. This study aimed to synthesize a novel, low-cytotoxic dentin desensitizer and investigate its occlusion effects on dentinal tubules. The biphasic stratification approach, a chemical reduction method, and the Stöber method were used to synthesize silver nanoparticle-loaded and nonporous silica-encapsulated mesoporous silica (Ag-MSNs@nSiO2), which was a noncrystalline structure with an average size of approximately 128 nm and a silver content of 3.506%. Atomic absorption spectrometry and the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide cell viability assay showed that Ag-MSNs@nSiO2 slowly released silver ions and had nearly no cytotoxicity. An electron microscope was used to observe the blocking effects on the dentinal tubules of sensitive tooth disc models, which were randomly divided into the following four groups: a deionized water group, a 5.9 M silver nitrate solution group, an Ag-MSNs@nSiO2 group, and a Gluma desensitizer group. There were no significant differences in the relative area of open dentinal tubules between the Ag-MSNs@nSiO2 group and the Gluma desensitizer group (P > 0.05). Detection of protein structures showed that multilevel structures of bovine serum albumin in dentin tubules were significantly changed by silver ions from Ag-MSNs@nSiO2. These results suggest that nearly noncytotoxic Ag-MSNs@nSiO2 was successfully synthesized by a series of methods. Ag-MSNs@nSiO2 occluded dentin tubules immediately and effectively. Moreover, the blockage effects may be enhanced and maintained by continuous condensation of proteins in dentinal tubules.

A Potassium Based Fluorine Containing Bioactive Glass for Use as a Desensitizing Toothpaste.

Potassium releasing bioactive glasses (BAGs) may offer improved relief for dentine hypersensitivity compared to conventional sodium containing BAGs by releasing K+ ions for nerve desensitization and occluding dentinal tubules to prevent fluid flow within dentinal tubules. Potassium oxide was substituted for sodium oxide on a molar basis in a fluoride containing BAG used in toothpastes for treating dentine hypersensitivity. The BAG powders were then immersed in an artificial saliva at pH 7 and tris buffer and the pH rise and ion release behavior were characterized by ICP-OES and ISE. The potassium and sodium containing BAGs were characterized by XRD, DSC, FTIR and NMR. Both BAGs presented amorphous diffraction patterns and the glass transition temperature of the potassium glass was higher than that of the sodium glass. The 31P MAS-NMR spectra indicated a peak at 2.7 ppm corresponding to apatite and a small peak at −103 ppm indicated crystallization to fluorapatite. Both BAGs dissolved and formed apatite at similar rates, although the dissolution of the potassium glass was slightly slower and it released less fluoride as a result of partial nanocrystallization to fluorapatite upon quenching. The potassium release from the potassium ions could potentially result in nerve deactivation when used in toothpastes.

Avian Eggshell Slurry as a Dentin Desensitizing Agent: An In Vitro Assessment Using Two Techniques

This study aims to evaluate the efficacy of avian eggshell slurry as a desensitizing agent compared to casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) containing Tooth Mousse. Eggshell powder was prepared and characterized using a scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). Forty dentin disks were immersed in 6% citric acid for 2 min to simulate hypersensitive dentin (baseline). Disks were then divided into two groups (n = 20) according to treatment received: eggshell slurry and commercially available Tooth Mousse desensitizing agent. Each group was further divided into two subgroups (n = 10). In subgroup 1, dentin discs were immersed in artificial saliva for four weeks whereas, in subgroup 2, discs underwent acid challenge. Environmental scanning electron microscope (ESEM) analysis and hydraulic conductance test were utilized to calculate dentinal tubules occlusion and reduction of dentin permeability percentages, respectively. Statistical analysis was performed using SPSS 22.0 at a significance level p ≤ 0.05. After application of desensitizing agents, the eggshell slurry group showed a significantly higher percentage of dentinal tubules occlusion compared to the Tooth Mousse group, whereas no significant difference existed in the percentage reduction of dentin permeability between both groups. After both immersion protocols, the eggshell slurry significantly occluded more dentinal tubules compared to Tooth Mousse. On the contrary, results of percentage reduction of dentin permeability revealed no significant difference between both subgroups after acid challenge. After artificial saliva immersion, Tooth Mousse showed a significantly higher percentage reduction of dentin permeability compared to the eggshell slurry. Avian eggshell slurry can effectively occlude open dentinal tubules compared to commercially available Tooth Mousse desensitizing agent. Avian eggshell slurry can be considered a promising material for the treatment of dentin hypersensitivity. How to cite this article: El Tahlawy AA, Saba DA, Bakir NG. Avian Eggshell Slurry as a Dentin Desensitizing Agent: An In Vitro Assessment Using Two Techniques. J Contemp Dent Pract 2021;22(5):532-537.

Evaluation The Efficiency of Nano Seashell, Sodium Fluoride And A Commercially Available Toothpaste On Dentinal Tubules Occlusion After Acid Attack Using Scanning Electron Microscope: In vitro Study.

Objectives: To evaluate the efficiency and stability of Nano seashell, Sodium Fluoride and Signal Complete 8 in treatment of dentine hypersensitivity. Methods: Forty freshly extracted premolar teeth were collected, disinfected, and sliced into 1.0± 0.1mm thickness. The dentin discs were randomly divided into two main groups of 20 discs each. Group 1(n=20): Dentin discs subjected to treatment not followed by acid challenge. Group 2 (n=20): Dentin discs subjected to treatment followed by acid challenge. Each group was further subdivided into 4 subgroups of 5 discs each according to the treatment used; Subgroup A (Control group): discs received no treatment; Subgroup B: discs treated with Sodium Fluoride paste; Subgroup C: discs treated with Nano Seashell paste; Subgroup D: discs treated with Signal Complete 8 toothpaste. Evaluation of dentinal tubules obliteration was done under scanning electron microscope. Results: There was a significant change in the diameter of tubules and percentage of occlusion for group 1. Group 2 (subjected to acid challenge after treatment) has shown high stability for subgroup B (Sodium Fluoride), followed by subgroup D (Signal Complete 8) then subgroup C (Nano seashell paste). Conclusion: Nano seashell and Sodium Fluoride caused significant increase of occluded dentinal tubules than Signal complete 8 but the mineral deposits formed by Sodium Fluoride showed higher resistance to acidic environment than those formed by Nano seashell.

In situ evaluation of desensitizing toothpastes for protecting against erosive tooth wear and its characterization

This five-phase, single-blind, crossover in situ trial evaluated the effects of desensitizing or anti-erosive toothpastes on dentin erosive wear and tubule occlusion. Some characteristics such as relative dentin abrasivity (RDA), viscosity (V), cytotoxicity, and fluoride and calcium (Ca) availability of the toothpastes were also tested. Samples were positioned on removable intraoral appliances from 15 volunteers (n=4), according to the groups, C-control (0 ppm fluoride), F-sodium monofluorophosphate (MFP), A-MFP and arginine+calcium carbonate, CSP-calcium sodium phosphosilicate, and CS-MFP and calcium silicate+sodium phosphate. Erosion-abrasion cycling was performed (1% citric acid, 2min, 6×/day; toothbrushing, 5s, 2×/day). Surface loss (SL) was evaluated by optical profilometry. Environmental scanning electron microscopy images (ESEM) counted the number of open dentin tubules (ODTs). Data were statistically analyzed (α=0.05). There were no significant differences in SL among groups (p=0.468). The ODT for CSP, CS, and A groups were significantly lower than the control. CSP and CS presented significantly less ODT than F, but they did not significantly differ from A. F and CS were more abrasive than all the other toothpastes; CSP was more abrasive than A, and C was the least abrasive. CSP presented higher V (p<0.05). All toothpastes presented lower cell viability than the control without toothpaste exposure. F and A presented significantly higher values of F- (p<0.05). All fluoride toothpastes had similar amount of Ca, differing from the control (p<0.05). Although the toothpastes caused similar degree of erosive wear, CSP and CS were able to occlude the dentin tubules. Desensitizing toothpastes containing calcium, sodium, phosphate, and silicate could be a suitable option for treating dentin hypersensitivity.

Melatonin-doped polymeric nanoparticles reinforce and remineralize radicular dentin: Morpho-histological, chemical and biomechanical studies

ObjectivesTo investigate the effectiveness of novel polymeric nanoparticles (NPs) doped with melatonin (ML) in reducing dentin permeability and facilitating dentin remineralization after endodontic treatment. MethodsThe effect of undoped NPs and ML-doped NPs (ML-NPs) was tested in radicular dentin, at 24 h and 6 m. A control group without NPs was included. ML liberation was measured. Radicular dentin was assessed for fluid filtration. Dentin remineralization was analyzed by scanning electron microscopy, AFM, Young’s modulus (Ei), Nano DMA-tan delta, and Raman analysis. ResultsML release ranged from 1.85 mg/mL at 24 h to 0.033 mg/mL at 28 d. Both undoped NPs and ML-NPs treated dentin exhibited the lowest microleakage, but samples treated with ML-NPs exhibited hermetically sealed dentinal tubules and extended mineral deposits onto dentin. ML-NPs promoted higher and durable Ei, and functional remineralization at root dentin, generating differences between the values of tan delta among groups and creating zones of stress concentration. Undoped-NPs produced closure of some tubules and porosities at the expense of a relative mineral amorphization. Chemical remineralization based on mineral and organic assessments was higher in samples treated with ML-NPs. When using undoped NPs, precipitation of minerals occurred; however, radicular dentin was not mechanically reinforced but weakened over time. SignificanceApplication of ML-NPs in endodontically treated teeth, previous to the canal filling step, is encouraged due to occlusion of dentinal tubules and the reinforcement of the radicular dentin structure.

The Stability of Dentin Surface Biobarrier Consisting of Mesoporous Delivery System on Dentinal Tubule Occlusion and Streptococcus Mutans Biofilm Inhibition.

BackgroundThe dentin exposure always leads to dentin hypersensitivity and/or caries. Given the dentin’s tubular structure and low mineralization degree, reestablishing an effective biobarrier to stably protect dentin remains significantly challenging. This study reports a versatile dentin surface biobarrier consisting of a mesoporous silica-based epigallocatechin-3-gallate (EGCG)/nanohydroxyapatite delivery system and evaluates its stability on the dentinal tubule occlusion and the Streptococcus mutans (S. mutans) biofilm inhibition.Materials and MethodsThe mesoporous delivery system was fabricated and characterized. Sensitive dentin discs were prepared and randomly allocated to three groups: 1, control group; 2, casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) group; and 3, the mesoporous delivery system group. The dentin permeability, dentinal tubule occlusion, acid and abrasion resistance, and S. mutans biofilm inhibition were determined for 1 week and 1 month. The in vitro release profiles of EGCG, Ca, and P were also monitored.ResultsThe mesoporous delivery system held the ability to sustainably release EGCG, Ca, and P and could persistently occlude dentinal tubules with acid and abrasion resistance, reduce the dentin permeability, and inhibit the S. mutans biofilm formation for up to 1 month compared with the two other groups. The system provided prolonged stability to combat oral adverse challenges and served as an effective surface biobarrier to protect the exposed dentin.ConclusionThe establishment of the dentin surface biobarrier consisting of a mesoporous delivery system indicates a promising strategy for the prevention and the management of dentin hypersensitivity and caries after enamel loss.

Nanotechnology: A New Strategy to Treat Dental Hypersensitivity

Dental Hypersensitivity is the most commonly encountered dental problems associated with short, sharp painrising from exposed dentine in response to stimuli such as tactile, osmotic and chemical. Hypersensitivitymay present on several teeth, in one area of the mouth, or on one specific tooth. DHS should be differentiatedfrom another tooth sensitivity which may elicit from other clinical conditions such as dental caries,microleakage, cracked tooth or fractured restorations. Several treatment strategies such as desensitizationof nerve endings, masking of dentin tubules, occlusion of dentin tubules, and iontophoresis, are prevalentin clinical practices. Stannous ions, most commonly used in toothpastes as stannous fluoride, have beendemonstrated to occlude dentine tubules in vitro. SnF2 toothpaste formulations have been used for severaldecades and are widely accepted as an effective DH treatment. Recently advanced nanotechnology has takena wide leap in improving the various measures in the treatment of hypersensitivity by its nano particles.Nano structures have superior hardness, elasticity and flexural strength leading to its better application.Biomimetic particles desensitizing effect of nanocrystals which is caused by the progressive closure of thetubular openings of the dentine with plugs. These advancements have progressed the growth in the treatmentof Dental Hypersensitivity and have evoked a great amount of attention for improving disease prevention.

Effect of a whitlockite glass-ceramic on the occlusion of dentinal tubules for dentin hypersensitivity treatment

A hipersensibilidade dentinária (HD) é caracterizada pela dor curta e aguda em resposta a estímulos externos, podendo ser tratada pela oclusão dos túbulos dentinários. Neste estudo, vidro original e uma vitrocerâmica do sistema 3CaO.P2O5-SiO2-MgO contendo whitlockita (fase de fosfato tricálcico substituído com Mg) foram avaliados quanto à eficácia no tratamento da HD. Um vidro bioativo com composição 52,75.(3CaO.P2O5)–30SiO2–17,25MgO (%p) foi tratado termicamente a 700°C e 775°C por 4 h. Terceiros molares humanos foram desmineralizados e distribuídos aleatoriamente em grupos: NT - controle negativo (sem tratamento), BG - controle positivo (tratado com Bioglass®45S5), GL - tratamento com vidro original e WGC - tratamento com whitlockita. Em seguida, amostras de dentina foram imersas em saliva artificial e armazenadas por 7 dias a 37ºC. Os biomateriais foram avaliados por Difração de Raios X (XRD) e Microscopia Eletrônica de Varredura (MEV). As amostras de dentina foram analisadas por MEV e ATR-FTIR, para identificar e quantificar variações composicionais na superfície dentinária. Foi identificada whitlockita como fase cristalina do GC, e sua presença leva à formação de partículas arredondadas, conforme mostrado por imagens de MEV. A análise de ATR-FTIR confirmou a formação de apatita na superfície de amostras BG, GL e WGC, o que foi corroborado pela oclusão dos túbulos dentinários, conforme imagens em MEV. As intensidades dos picos de infravermelho foram comparadas estatisticamente. Em relação à reatividade superficial pela análise semiquantitativa de FTIR, o GC demonstrou similaridade com o Bioglass®45S5 indicando que este material é promissor no tratamento de HD.

Use of phosphorylated PAMAM and carboxyled PAMAM to induce dentin biomimetic remineralization and dentinal tubule occlusion.

It is crucial to emphasize the biomineralization therapeutic method to repair etched dentin in clinic. Non-collagenous proteins (NCPs) play critical role in the biomineralization of dentine. In this paper, we synthesized the phosphate-terminated polyamidoamine dendrimer (PAMAM-PO3H2) by one-step modification successfully and examined by Fourier-transform infrared spectroscopy (FTIR) and 1H-nuclear Magnetic Resonance (1H-NMR) to characterize the structure of PAMAM-PO3H2. PAMAM-PO3H2 and carboxylterminated dendrimers (PAMAM-COOH) were applied as the dual biomimetic analogs of NCPs. Through the characterization of FT-IR, field emission scanning electron microscope (FE-SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), the surfaces of human dentin were covered with regenerated crystals and the dentinal tubules were occluded by PAMAM-PO3H2 and PAMAM-COOH. In summary, the combination of PAMAM-PO3H2 and PAMAM-COOH may be another feasible therapeutic method for the treatment of dentin caries and dentin hypersensitivity.

In Vitro Evaluation of Desensitizing Agents Containing Bioactive Scaffolds of Nanofibers on Dentin Remineralization.

This study evaluated the effect of the incorporation of bioactive nanofibers in desensitizing agents on dentin permeability. Sixty disks of dentin were randomly distributed in four groups (n = 15). Distribution was based on the desensitizing agents, fluoride varnish and self-etching adhesive, and the presence of nanofibers: C (self-etching adhesive Clearfil SE Bond), CN (Clearfil SE Bond with 1% nanofiber), D (Duraphat varnish), and DN (Duraphat varnish with 1% nanofiber). Dentin permeability was determined using hydraulic conductivity. For a qualitative analysis, confocal laser microscopy and scanning electron microscopy were performed. The C group showed the lowest hydraulic conductance (Lp%) (89.33), while the DN group showed the highest Lp% (116.06). No statistical significance was observed in the Lp% values in all groups after the treatment and 6% citric acid challenge (p > 0.239). In the images, the CN group presented a higher superficial and intratubular deposition. In addition, this group presented a more homogeneous dentin surface and wide occlusion of dentinal tubules than the other treatments. Despite there being no statistical differences among the treatments employed, the images showed that the CN group presented a higher surface and intratubular deposition compared to the other treatments, even after the acid challenge.

Interaction of storage medium and silver diamine fluoride on demineralized dentin.

ObjectiveThe effects of saliva on demineralized dentin and silver diamine fluoride (SDF) were investigated in vitro.MethodsDentin samples stored in deionized water (DIW), buffer solution (BS), basal medium mucin (BMM), and unstimulated whole saliva (UWS) were demineralized for 3 days and immersed in the same storage media. SDF as a 38 mass% solution was applied to the dentin samples for 3 minutes after they had been replaced in their respective medium. Surfaces were analyzed by scanning electron microscopy, energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD).ResultsScanning electron microscopy showed various surface deposits and coatings, including occlusion of dentinal tubules. DIW resulted in the thinnest coating, whereas BMM resulted in the thickest. EDX and XPS showed the formation of metallic silver and silver compounds in all four media, with the greatest formation in BS. XRD indicated that the main product was silver chloride except in DIW. Sulphur was found in BMM and UWS. EDX and XPS detected fluoride and XRD detected calcium fluoride and fluorohydroxyapatite in BS, BMM, and UWS.ConclusionThe interaction between SDF and demineralized dentin was dependent upon the storage medium. BMM provided an outcome most similar to human saliva.