Dentinal Tubule Occlusion Research Articles

Patency of opened dentinal tubules after treatment with Biomimetic materials

Objectives: To estimate the dentinal tubules occlusion potential of biomimetic materials as nano-hydroxyapatite and self-assembling peptides and to compare their results with a traditionally used sodium fluoride material.Materials and methods: Standardized forty dentin disks were obtained from extracted molars. They were treated with citric acid 6% for 2 min to simulate the hypersensitive dentin. Disks were classified into four equal groups (n=10); Control group without treatment; Sodium fluoride (Bifluorid 10, VOCO, Germany); self-assembling peptide (CurodontTM Protect, Credentis, Switzerland) or nanohydroxyapatite nHAp containing material (Remin Pro, VOCO, Germany). Fluoride varnish was applied twice during the test period (7 days) and the biomimetic desensitizing agents were left for 5 minutes/ once daily. Specimens were stored in artificial saliva during the seven days. Specimens were analyzed using scanning electron microscope (500X). Quantitative analysis of the surface area (µm2) of the patent dentinal tubules in the scanned images was done by using digimizer image analysis software (version 3.7.0.0). Statistical analysis was done using One way-ANOVA followed by Tuckey’s post hoc test for comparison (P≤ 0.05).Results: In the control group, the dentinal tubules were widely opened after being demineralized with the highest dentinal tubules mean surface area recorded (592.5±68.0 µm2). Sodium fluoride group revealed partially obliterated dentinal tubules with intratubular deposits leaving a mean surface area of 260.0± 53.3 µm2. Opened areas in the fluoride group are statistically equal to those in the self-assembling peptide group (203.5±99.3). In the nanohydroxyapatite group, almost complete sealing of the dentinal tubules was evident with the least mean surface area of the opened parts(35.0±5.3). The difference between the study groups was statistically significant. Conclusions: The desensitizing agents studied showed different abilities to change the dentin surface micromorphology, with partial or total occlusion of dentinal tubules. Nanohydroxyapatite containing agent is a promising biomimetic material for management of dentin hypersensitivity.

In Vitro Effect of Innovative Desensitizing Agents on Dentin Tubule Occlusion and Erosive Wear.

The purpose of this study was to evaluate the effects of four in-office desensitizing products on dentin tubule occlusion and erosive wear. Dentin hypersensitivity was simulated by EDTA application for five minutes. The specimens were randomly allocated into five groups (n=11), according to treatment: No treatment - Control (C), Duraphat (DUR), Desensibilize Nano P (NP), ClinPro XT Varnish (XTV), and ClinPro White Varnish (CWV). They were then submitted to erosive/abrasive cycling for five days. After EDTA, treatment, and cycling, the specimens were analyzed with an environmental scanning electron microscope (ESEM) to verify the number of opened dentin tubules (ODT) which were counted by using ImageJ software, and with a profilometer to determine the surface curvature/loss. ESEM data were analyzed with two-way repeated measure analysis of variance and Tukey tests. For the profilometer, data were analyzed with Kruskal-Wallis, Tukey, and Mann-Whitney tests. After treatment, all groups showed lower ODT than the control, without significant differences between them. After cycling, the only group that showed lower ODT than the control was group XTV; however, it did not significantly differ from the other groups. For the profilometric analysis, there were significant differences in SL between the experimental times after treatment and after cycling for all groups ( p<0.05). After cycling, no surface loss was detected in groups DUR and XTV, which presented a significantly different curvature than group NP and the control group, but not from group CWV. Surface loss was detected for the control and groups NP and CWV, without difference among them. All desensitizing agents tested presented promising results concerning the obliteration of dentin tubules immediately after treatment. XTV was the only desensitizer capable of preventing the reopening of the tubules after the erosive/abrasive challenges. XTV and DUR presented a protective effect against dentin erosive wear.

Nanogels of carboxymethyl chitosan and lysozyme encapsulated amorphous calcium phosphate to occlude dentinal tubules.

This study aimed to develop of a rapid and effective method to occlude dentinal tubules using carboxymethyl chitosan and lysozyme (CMC/LYZ) nanogels with encapsulated amorphous calcium phosphate (ACP) based on the transformation of ACP to HAP. In this work, CMC/LYZ was used to stabilize ACP and form CMC/LYZ-ACP nanogels, and then the nanogel-encapsulated ACP was applied to exposed dentinal tubule surfaces. The morphology of the nanogels was examined by transmission electron microscopy (TEM). Distribution and quantity of elements in CMC/LYZ-ACP nanogels were determined by element mapping and energy dispersive X-Ray spectroscopy (EDX). Scanning electron microscopy (SEM) images, XRD measurements and nanoindentation were applied to check the efficacy of tubular occlusion. TEM revealed that CMC/LYZ-ACP nanogels were spherical dense gel particles with size approximately 50-500 nm. Element mapping and EDX indicated that C, N, O, Ca, P, and S in the microspheres are thoroughly represented. SEM images shows that the thickness of the coating layer was approximately 1-2 μm and the depth to which the mineralized substance enters the dentinal tubule was approximately 4-8 μm. XRD measurements and nanoindentation indicated that the occluding mineralized substance observed were similar to nature dentin. CMC can form spherical dense nanogels loaded with ACP under the participation of lysozyme. The CMC/LYZ-ACP nanogels could increase the dentinal tubule occluding effectiveness. These results indicated that finding and developing novel nanomaterials of CMC/LYZ-ACP would be an effective strategy for the treatment of dentin hypersensitivity.

Evaluation of the effects of Er:YAG laser, Nd:YAG laser, and two different desensitizers on dentin permeability: in vitro study.

The purpose of this in vitro study was to evaluate and compare the efficacy of erbium-doped yttrium aluminum garnet (Er:YAG) laser, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, PrevDent nano-hydroxyapatite toothpaste plus Repairing Serum Kit (PNH), and NUPRO Sensodyne Prophylaxis Paste with NovaMin (NPP) on dentin permeability reduction. Forty dentin discs obtained from bovine incisors were divided into four study groups: Er:YAG laser-treated (2940nm; 0.2W, 80mJ/pulse, 3Hz); Nd:YAG laser-treated (1064nm; 1W, 10Hz); PNH-treated; and NPP-treated groups. The quantitative changes in permeability of each dentin disc were measured using a computerized fluid filtration method (CFFM) before and after desensitizer treatments. The data were analyzed using the Wilcoxon, paired-samples t, Kruskal-Wallis, and Mann-Whitney U tests. The dentin surfaces and tubules were also morphologically detected by scanning electron microscopy (SEM). In all groups, dentin permeability was significantly reduced after the desensitizer and laser treatments (p < 0.05). Among the groups, we detected a significant difference in only when comparing the Er:YAG laser- and NPP-treated groups (p = 0.034). SEM analysis revealed physical changes in the dentin surface in all groups. This in vitro study shows that all tested desensitizers and laser treatments reduced dentin permeability. Also, surface changes, such as complete or partial occlusion or shrinkage of dentin tubules, were observed in all groups. Although the laser groups performed best, the PNH protocol can be considered as an alternative therapeutic product. In addition, clinical and laboratory studies should be performed for this product, and their efficacy should be assessed by combined therapy with lasers.

Dentinal tubule occluding capability of nano‐hydroxyapatite; The in‐vitro evaluation

In this in-vitro study, the effectiveness of experimental pure nano-hydroxyapatite (nHAP) and 1%, 2%, and 3% F¯ doped nano-HAp on dentine tubule occlusion was investigated. And also, the cytotoxicity of materials used in the experiment was evaluated. Nano-HAp types were synthesized by the precipitation method. Forty dentin specimens were randomly divided into five groups of; 1-no treatment (control), 2-specimens treated with 10% pure nano-HAp and 3, 4, 5 specimens treated with 1%, 2%, and 3% F- doped 10% nano-HAp, respectively. To evaluate the effectiveness of the materials used; pH, FTIR, and scanning electron microscopy evaluations were performed before and after degredation in simulated body fluid. To determine cytotoxicity of the materials, MTT assay was performed. Statistical evaluations were performed with F and t tests. All of the nano-HAp materials used in this study built up an effective covering layer on the dentin surfaces even with plugs in tubules. It was found that this layer had also a resistance to degradation. None of the evaluated nano-HAp types were have toxicity. Fluoride doping showed a positive effect on physical and chemical stability until a critical value of 1% F- . The all evaluated nano-HAp types may be effectively used in dentin hypersensitivity treatment. The formed nano-HAp layers were seem to resistant to hydrolic deletion. The pure and 1% F- doped nano-HAp showed the highest biocompatibility thus it was assessed that pure and 1% F- doped materials may be used as an active ingredient in dentin hypersensitivity agents.

Dentin sealing and antibacterial effects of silver-doped bioactive glass/mesoporous silica nanocomposite: an in vitro study.

To synthesize a silver-doped bioactive glass/mesoporous silica nanoparticle (Ag-BGN@MSN), as well as to investigate its effects on dentinal tubule occlusion, microtensile bond strength (MTBS), and antibacterial activity. Ag-BGN@MSN was synthesized using a modified "quick alkali-mediated sol-gel" method. Demineralized tooth disc models were made and divided into four groups; the following treatments were then applied: group 1-no treatment, group 2-bioglass, group 3-MSN, group 4-Ag-BGN@MSN. Next, four discs were selected from each group and soaked into 6wt% citric acid to test acid-resistant stability. Dentinal tubule occlusion, as well as the occlusion ratio, was observed using field-emission scanning electron microscopy. The MTBS was also measured to evaluate the desensitizing effect of the treatments. Cytotoxicity was examined using the MTT assay. Antibacterial activity was detected against Lactobacillus casei, and ion dissolution was evaluated using inductively coupled plasma optical emission spectrometry. Ag-BGN@MSN effectively occluded the dentinal tubule and formed a membrane-like layer. After the acid challenge, Ag-BGN@MSN had the highest rate of dentinal tubule occlusion. There were no significant differences in MTBS among the four groups (P > 0.05). All concentrations of Ag-BGN@MSN used had a relative cell viability above 72%. Ag-BGN@MSN was successfully fabricated using a modified sol-gel method. The Ag-BGN@MSN biocomposite effectively occluded dentinal with acid-resistant stability, did not decrease bond strength in self-etch adhesive system, had low cytotoxicity, and antibacterial effect. Dentinal tubule sealing induced by Ag-BGN@MSN biocomposite with antibacterial effect is likely to increase long-term stability in DH.

Effects of different treatments on chemical and morphological features of eroded dentin.

To evaluate the treatment of eroded dentin (Sensodyne Repair & Protect™, Er:YAG laser and combinations). The occlusal surfaces of 25 third molars were sectioned 1.5mm in thickness. After an erosion cycle (5min in demineralizing solution + 3h in remineralizing solution; six cycles a day for 8days), the samples were divided into five groups (n = 5): (E) erosion - control; (ES) erosion + Sensodyne Repair & Protect (NovaMin); (EL) erosion + Er:YAG laser (40mJ, 10Hz, 0.4W, 50μs, 3.1J/cm2, 63W/cm2); (ELS) erosion + Er:YAG laser + Sensodyne; and (ESL) erosion + Sensodyne + Er:YAG laser. Following storage in ultrapure water (37°C/14days), the Ca/P ratio was evaluated by EDXRF and the morphology surfaces examined in SEM. The percentage of exposed dentin tubules was calculated. One-way analysis of variance and Tukey's test at 5% were used to treat the data. The Ca/P ratio was higher in E and ES groups. More exposed dentin tubules were found in E group and less exposed tubules were found in the ES group (p < 0.0001). When the toothpaste and laser were combined, the number of occluded dentin tubules was higher when laser was performed first (ELS). A positive effect was found when the laser and toothpaste were combined.

Dentinal tubule sealing effects of 532-nm diode-pumped solid-state laser, gallic acid/Fe3+ complex, and three commercial dentin desensitizers.

The purpose of this study was to compare dentinal tubule sealing effects of a 532-nm diode-pumped solid-state (DPSS) laser, gallic acid/Fe3+ complex, and three commercially available dentin desensitizers. Human premolars (n = 44) extracted for orthodontics had standardized cervical cavities prepared, etched (37% phosphoric acid) and randomly assigned to either a control (n = 4), or one of five treatment groups (n = 8/group). Desensitizing treatments were either a 532-nm DPSS laser, gallic acid/Fe3+ complex, oxalate-based Super Seal™ (SS), DIO™ Enamel Coating Pen Pro Tooth (Dio), or adhesive-type Hybrid Coat™ (HC). Dentinal fluid flow (DFF) was monitored continuously in real time during the application of each desensitizing agent, by using a nanoliter-scaled fluid flow-measuring device. Following treatment, morphological changes on dentinal surfaces and within tubules were observed by scanning electron microscopy (SEM). DFF rates were significantly reduced after treatment in all experimental groups (P < 0.05), except SS (P > 0.05). The gallic acid/Fe3+ complex reduced DFF rates the most, and significantly (P < 0.05) more than the three commercial dentin desensitizers. There were no significant differences in DFF reduction rates between the gallic acid/Fe3+ complex and the DPSS laser groups (P > 0.05). There were no significant differences in DFF reduction rates among the three commercial dentin desensitizers (P > 0.05). SEM examination of treated dentin showed that the degree of occlusion of dentinal tubules correlated closely with the corresponding reduction in DFF rates. The gallic acid/Fe3+ complex and 532-nm DPSS laser were superior to other desensitizing methods in occluding dentinal tubules and reducing DFF rates.

8DSS peptide induced effective dentinal tubule occlusion in vitro

ObjectiveEight repetitive nucleotide sequences of aspartate–serine–serine (8DSS) derived from dentin phosphoprotein (DPP) has been proved to be a good remineralization agency. In this study, 8DSS peptide was employed to induce dentinal tubule occlusion. MethodsDentin samples were acid-etched, and then the samples were coated with 8DSS solution. The binding capacity of 8DSS to acid-etched dentin was tested by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Subsequently, the 8DSS-treated dentin samples were immersed in artificial saliva for 1, 2 and 4 weeks. After 4 weeks, the remineralized dentin was treated with 6wt% citric acid (pH 1.5) solution for 1min. Dentin permeability measurement and scanning electron microscopy (SEM) were carried out after different periods. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were used to identify the mineral phase of the regenerated minerals. ResultsThe results showed that 8DSS had a good binding capacity to the acid-etched dentin, and significantly reduced the dentin permeability by inducing minerals deposited within the dentinal tubules. After 4 weeks, all the dentinal tubules were occluded by large bulk of regenerated minerals, which largely decreased the diameters of the tubules. The regenerated minerals deposited with a deep depth within the dentinal tubules, ensuring an effective occlusion even after an acid challenge. The results of XRD and EDS confirmed that the regenerated minerals were mainly hydroxyapatite (HA). Significance8DSS peptide induced strong dentinal tubule occlusion. 8DSS have a great potential to be used in the treatment of dentin hypersensitivity in the future.

Application of electrophoretic deposition to occlude dentinal tubules in vitro

ObjectivesThis study aims to apply electrophoretic deposition (EPD) for occlusion of dentinal tubules in vitro and investigate its effect on tubule occlusion and shear bond strength (SBS). MethodsCharged mesoporous silica nanoparticles (MSNs) were synthesized and characterized through field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), dynamic light scattering (DLS), and Fourier transform infrared (FT-IR) spectroscopy analyses. Thirty-nine sensitive dentin specimens were modeled and assigned randomly to three groups with different treatments (n = 13 each): group 1, immersion in the MSN suspension; and groups 2 and 3, anodic EPD with the specimen on the negative and positive electrode respectively. The effect of dentinal tubule occlusion was evaluated by dentin permeability test (n = 10 each) and FESEM examination (n = 3 each). Moreover, 18 specimens were grouped (n = 6 each) and treated in the same method. A resin stick was bonded onto each of the specimen using a self-etch adhesive (single bond universal) for SBS testing. ResultsNegatively-charged MSNs were synthesized and characterized as small and well-dispersed particles. After the EPD treatment (group 3), the dentinal tubules were effectively occluded by MSNs, which infiltrated into the tubules at a depth of approximately 7–8 μm and tightly associated with the tubular inwalls. SBS was not significantly different among the three groups (P > 0.05). ConclusionsSynthesized MSNs were deposited into dentinal tubules by EPD treatment without compromising dentin bond strength. Clinical significanceApplication of EPD is a new approach for occlusion of dentinal tubules and exhibits potential in the study of dentin hypersensitivity.

Effectiveness for dentin hypersensitivity treatment of non-carious cervical lesions: a meta-analysis.

The aim of this review is to conduct a systematic review and meta-analysis comparing the effectiveness of in-home or in-office treatments for dentin hypersensitivity. An electronic search without restriction on dates or languages was performed in four electronic databases until March 2017. In addition, hand-searches in regular journals and in the gray literature were also conducted. To develop the search strategy, clinical questions were formulated using the PICOS method. Eligibility criteria included randomized clinical trials (RCTs) that compared the effectiveness of different agents for the treatment of dentin hypersensitivity through chemical occlusion, physical occlusion, nerve desensitization, or photobiomodulation (low-level light therapy). This systematic review was registered in PROSPERO under number CRD42016039394. Twenty-five RCTs (16 parallel; 9 split-mouth), published from 1992 to 2016, were included. The results of the meta-analysis showed that in-office subgroups treated with chemical or physical occlusion of dentin tubules and nerve desensitization had a statistically significant difference from placebo, with P < 0.00001, P < 0.00001, and P = 0.02, respectively. For in-home treatments, the results of the meta-analysis showed that only those subgroups treated with chemical occlusion of dentin tubules and nerve desensitization exhibited a statistically significant difference from placebo, with P < 0.00001 and P = 0.03, respectively. The results of pairwise meta-analysis suggest that among in-office treatments, dentinal tubule occlusion (whether chemical or physical) and nerve desensitization provide the best outcomes for treatment of dentin hypersensitivity. For in-home treatments, only chemical occlusion of dentin tubules and nerve desensitization showed a greater treatment efficacy than placebo and the difference was statistically significant.

Evaluation of dentinal tubule occlusion using a desensitizing toothpaste and mouthwash for a period of 60 days: Scanning electron microscopy analysis

Introduction: This study aims to evaluate the dentinal tubule occlusion using a desensitizing toothpaste, mouthwash, and their combination for a period of 60 days under scanning electron microscope (SEM). Materials and Methods: A total of 120 extracted premolars were collected, cleaned of gross debris, and sectioned labiolingually to obtain 60 mesial and distal surfaces. Smear layer was removed by etching the blocks in 6% citric acid for 2 min and rinsed in distilled water. The specimens were divided into four groups with a control group, mouthwash, toothpaste, and their combination groups brushed twice daily for 60 days. The sections were viewed under SEM to detect the percentage of tubule occlusion. Groups were analyzed using the Chi-square test. Results: The toothpaste group showed better tubule occlusion followed by the combination and mouthwash group (P > 0.05), but there was no statistically significant difference between all the three groups. All the groups showed complete tubule occlusion on the 28th, 45th, and 60th day. Conclusions: The dentin tubule occlusion was in the order: toothpaste group > combination group > mouthwash group. Maximum dentine tubule occlusion was found by the 28th day in all the groups.

Effectiveness of Clinpro XT in Reducing Dentin Permeability and its Resistance to Acid Challenges.

To evaluate the efficacy of Clinpro XT in reducing dentin permeability and the stability of this effect after different acid challenges. Sixty-five roots of extracted human third molars were used. From each tooth, one dentin specimen was prepared and connected to a fluid filtration system to measure the dentin permeability after each of the following steps: sample preparation; treatment with 37% phosphoric acid; application of Clinpro XT; three acid challenges. Specimens were randomly assigned to 5 groups (n = 13) according to the acidic solution applied: Coca-Cola, natural lemon juice, wine vinegar, white wine and Red Bull energy drink. An additional 10 third molars were used to evaluate the degree of occlusion of the dentinal tubules and the surface roughness. Clinpro XT statistically significantly reduced dentin permeability after just a single application. No statistically significant increase in dentin permeability could be detected after three consecutive challenges. The application of Clinpro XT promotes the occlusion of dentinal tubules and reduces the surface roughness. The Clinpro XT is effective in reducing dentin permeability. This effect persists even after acid challenges.

Dentine Tubule Occlusion by Novel Bioactive Glass-Based Toothpastes.

There are numerous over-the-counter (OTC) and professionally applied (in-office) products and techniques currently available for the treatment of dentine hypersensitivity (DH), but more recently, the use of bioactive glasses in toothpaste formulations have been advocated as a possible solution to managing DH. Aim. The aim of the present study, therefore, was to compare several bioactive glass formulations to investigate their effectiveness in an established in vitro model. Materials and Methods. A 45S5 glass was synthesized in the laboratory together with several other glass formulations: (1) a mixed glass (fluoride and chloride), (2) BioMinF, (3) a chloride glass, and (4) an amorphous chloride glass. The glass powders were formulated into five different toothpaste formulations. Dentine discs were sectioned from extracted human teeth and prepared for the investigation by removing the cutting debris (smear layer) following sectioning using a 6% citric acid solution for 2 minutes. Each disc was halved to provide test and control halves for comparison following the brushing of the five toothpaste formulations onto the test halves for each toothpaste group. Following the toothpaste application, the test discs were immersed in either artificial saliva or exposed to an acid challenge. Results. The dentine samples were analyzed using scanning electron microscopy (SEM), and observation of the SEM images indicated that there was good surface coverage following artificial saliva immersion. Furthermore, although the acid challenge removed the hydroxyapatite layer on the dentine surface for most of the samples, except for the amorphous chloride glass, there was evidence of tubular occlusion in the dentine tubules. Conclusions. The conclusions from the study would suggest that the inclusion of bioactive glass into a toothpaste formulation may be an effective approach to treat DH.

Comparative Evaluation of Dentinal Tubule Occlusion Ability of Three Commercially Available Desensitizing Dentifrices: An in vitro Scanning Electron Microscope Study

Comparative Evaluation of Dentinal Tubule Occlusion Ability of Three Commercially Available Desensitizing Dentifrices: An in vitro Scanning Electron Microscope Study

Effect of tetracalcium phosphate/monetite toothpaste on dentin remineralization and tubule occlusion in vitro

ObjectivesTo investigate the tubule occlusion and remineralization potential of a novel toothpaste with active tetracalcium phosphate/monetite mixtures under de/remineralization cycling. MethodsDentin de/remineralization cycling protocol consisted of demineralization in 1% citric acid at pH 4.6 with following remineralization with toothpastes and soaking in artificial saliva. Effectiveness of toothpastes to promote remineralization was evaluated by measurement of microhardness recovery, analysis of surface roughness, thickness of coating and scanning electron microscopy. ResultsThe novel tetracalcium phosphate/monetite dentifrice had comparable remineralization potential as commercial calcium silicate/phosphate (SENSODYNE®) and magnesium aluminum silicate (Colgate®) toothpastes and significantly higher than control saliva (p<0.02). Surface roughness was significantly lower after treatment with prepared and SENSODYNE® dentifirice (p<0.05). The coatings on dentin surfaces was significantly thicker after applying toothpastes as compared to negative control (p<0.001). ConclusionsThe new fluoride toothpaste formulation with bioactive tetracalcium phosphate/monetite calcium phosphate mixture effectively occluded dentin tubules and showed good dentin remineralization potential under de/remineralization cycling. It could replace professional powder preparation based on this mixture. It was demonstrated that prepared dentifrice had comparable properties with commercial fluoride calcium silicate/phosphate or magnesium aluminum silicate dentifrices.

Human Dentinal Tubules alterations after desensitizing Dentifrices use: An ex vivo study

Objective: Evaluated the effects of desensitizing dentifrices on dentinal tubule occlusion in human teeth thought qualitative and quantitative analysis.

Evaluation of Dentinal Changes Following Application of Three Different Desensitizing Agents

The aim of this in vitro study was to evaluate the effect of three desensitizing tooth pastes on the dentinal tubule occlusion. Thirty dentin discs having a thickness of 3 mm were obtained by cutting human teeth. The discs were submersed in citric acid for 30 seconds to open the dentin tubules. Then the discs were cut in two halves. In each group 10 halves were kept in 0.9% NaCl solution) and the other 10 halves were exposed to the action of one of the tested desensitizing toothpastes. The dentin samples were placed in the machine designed to simulate tooth brushing. Three commercial desensitizing toothpastes were chosen to be applied on dentin surface. The morphology of dentin samples and the level of tubule occlusion was scored using scanning electron microscope. All the three desensitizing toothpastes demonstrated significant effects on dentinal tubule occlusion. The tooth paste containing arginine and calcium carbonate as active ingredients showed the highest degree of tubule occlusion, followed by the dentifrice containing strontium acetate and sodium fluoride.

Development of Epigallocatechin-3-gallate-Encapsulated Nanohydroxyapatite/Mesoporous Silica for Therapeutic Management of Dentin Surface.

In dental clinic, unsatisfactory management of the dentin surface after dentin exposure often leads to the occurrence of dentin hypersensitivity and caries. Current approaches can occlude the tubules on the dentin surface to relieve dentin hypersensitivity; however, the blocked tubules are generally weak in combating daily tooth erosion and abrasion. Moreover, cariogenic bacteria, such as Streptococcus mutans, produce biofilm on the dentin surface, causing caries and compromising the tubules' sealing efficacy. To overcome this problem, the present study focused on establishing a versatile biomaterial, epigallocatechin-3-gallate-encapsulated nanohydroxyapatite/mesoporous silica nanoparticle (EGCG@nHAp@MSN), for therapeutic management of the dentin surface. The effectiveness of the biomaterial on dentinal tubule occlusion, including resistances against acid and abrasion, was evaluated by field-emission scanning electron microscopy (FESEM) and dentin permeability measurement. The inhibitory capability of the biomaterial on S. mutans biofilm formation was investigated by confocal laser scanning microscopy (CLSM), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony forming units (CFU) counts, and FESEM. Results demonstrated for the first time that the use of EGCG@nHAp@MSN on the dentin surface was capable of effectively occluding dentinal tubules, reducing dentin permeability, and achieving favorable acid- and abrasion-resistant stability. Furthermore, EGCG@nHAp@MSN held the capability to continuously release EGCG, Ca, and P, and significantly inhibit the formation and growth of S. mutans biofilm on the dentin surface. Thus, the development of EGCG@nHAp@MSN bridges the gap between multifunctional concept and dental clinical practice and is promising in providing dentists a therapeutic strategy for the management of the dentin surface to counter dentin hypersensitivity and caries.

Re-crystallization of silica-based calcium phosphate glass prepared by sol–gel technique

Abstract Bioactive glass (BG) is a potential material for treating dentin hypersensitivity owing to its high solubility. In this study, we synthesized 80S-BG bioactive glass samples using a sol–gel technique and mixed with various hardening agents. The obtained material could be used in human dentinal dentinal tubule occlusions. X-ray diffraction (XRD), scanning electronic microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) measurements were employed to investigate the physiochemical properties and dentinal dentinal tubule occlusion efficiency by mixing the 80S bioactive glass (80S-BG) with various hardening agents. The major crystallite phase obtained on mixing 80S-BG with phosphoric acid (PA) was Ca(H 2 PO 4 ) 2 ·H 2 O. The mixture of 80S-BG powders and 20, 30, or 40 wt% PA acted as a hardening agent and achieved a dentinal tubule penetration depth of 30.7–62.6 µm. 80S-BG on mixing with suitable PA agents exhibited a short reaction time and good operability, making it feasible for use in occluding dentinal tubules. 80S-BG mixed with hardening agents exhibited a greater potential for treating dentin hypersensitivity as compared to the 80S-BG not mixed with any hardening agents.