Effects of desensitizing dentifrices on dentin tubule occlusion and resistance to erosive challenges

Background Many studies have demonstrated efficacy of casein phosphopeptide (CPP) containing products for dentin tubule occlusion for treatment of dentin sensitivity, but their effectiveness under dynamic erosive challenges remains to be elucidated. The purpose of the present study was to investigate the effectiveness of a desensitizing dentifrice containing CPP in occluding dentin tubules and resisting erosive challenges in comparison to that containing polyvinyl methyl ether/maleic acid (PVM/MA) copolymers. Methods A total of 33 dentin discs were prepared from coronal sections of human third molars and divided into 3 groups: a toothpaste containing CPP; a toothpaste containing PVM/MA and submicron silica; and a regular toothpaste (Controls). A soft-bristle toothbrush was used to brush the dentin discs with the dentifrices for 45 strokes in 30 s at a force of approximately 200 g. The brushing cycle was repeated after immersion of the dentin discs in artificial saliva overnight. The dentin discs were then challenged in orange juice for 10 min in an incubator rocking at 120 rpm. Three fields were randomly selected on each dentin disk surface to assess dentin tubule occlusions after each brushing cycle and after orange juice challenge with a 3D laser scanning microscope. Specimen cross sections were examined with a scanning electron microscope equipped with energy dispersive spectroscopy (SEM/EDS). Results After the first and second cycles of brushing, dentin tubules were occluded on average by 56.3% and 85.7% in CPP group, 66.2% and 88.1% in PVM/MA group, and 0.0 and 13.0% in the controls, respectively. There were no statistically significant differences in dentin tubule occlusions between the CPP and PVM/MA groups after two cycles of brushing (p>0.05). After dynamic erosive challenges with orange juice, 20.3% of the dentin tubules in the CPP group, 79.1% in the PVM/MA group and none in the control remained occluded (P<0.05). SEM/EDS imaging showed that dentin tubules were blocked with plugs containing dentifrice substances in CPP and PVM/MA groups after treatments, but none in the controls. Conclusions Desensitizing dentifrices containing CPP or PVM/MA could effectively occlude dentin tubules after two cycles of brushing. PVM/MA in combination with submicron silicon dioxide exhibited stronger resistance to dynamic erosive challenges by acidic beverages. Inorganic fillers that can enter dentin tubules and resist erosive challenges may be key for desensitizing dentifrices.

Hydroxyapatite, a potent agent to reduce dentin hypersensitivity; systematic review

Objective: This study reviews different modes of application of hydroxyapatite for treatment of dentin hypersensitivity via dentinal tubule occlusion. Methods: Literature search was performed using keywords, “hydroxyapatite and dentin hypersensitivity, hydroxyapatite and dentinal tubule occlusion, hydroxyapatite and dentin permeability, dentinal tubule occlusion” on Pubmed, Science Direct and Web of Science, which involved the results of previous 10 years (2009-2018). After screening, 16 studies were included in systematic review. Results: The results of in-vitro studies showed that application of hydroxyapatite caused dentinal tubule occlusion leading to reduction in dentin permeability and reduction in dentin hypersensitivity. Conclusion: Hydroxyapatite has the potential to reduce dentin hypersensitivity via dentinal tubule occlusion within 2-8 weeks. Keywords: Dentin hypersensitivity, Hydroxyapatite, Dentinal tubule occlusion. Continuous...

Novel Pastes Containing Polymeric Nanoparticles for Dentin Hypersensitivity Treatment: An In Vitro Study

Tubule occlusion and remineralization are considered the two main goals of dentin hypersensitivity treatment. The objective is to assess the ability of dentifrices containing zinc-doped polymeric nanoparticles (NPs) to enduringly occlude the dentinal tubules, reinforcing dentin’s mechanical properties. Fifteen dentin surfaces were acid-treated for dentinal tubule exposure and brushed with (1) distilled water, or with experimental pastes containing (2) 1% of zinc-doped NPs, (3) 5% of zinc-doped NPs, (4) 10% of zinc-doped NPs or (5) Sensodyne®. Topographical and nanomechanical analyses were performed on treated dentin surfaces and after a citric acid challenge. ANOVA and Student–Newman–Keuls tests were used (p < 0.05). The main results indicate that all pastes produced tubule occlusion (100%) and reinforced mechanical properties of intertubular dentin (complex modulus was above 75 GPa). After the citric acid challenge, only those pastes containing zinc-doped NPs were able to maintain tubular occlusion, as specimens treated with Sensodyne® have around 30% of tubules opened. Mechanical properties were maintained for dentin treated with Zn-doped NPs, but in the case of specimens treated with Sensodyne®, complex modulus values were reduced below 50 GPa. It may be concluded that zinc-doped NPs at the lowest tested concentration produced acid-resistant tubular occlusion and increased the mechanical properties of dentin.

“COMPARATIVE EVALUATION OF EFFECT ON DENTINAL TUBULE OCCLUSION BY THREE DIFFERENT DESENSITIZING DENTIFICES: A SEM STUDY”

Introduction: Dentine hypersensitivity (DH) occurs on exposed dentine and is dependent on the patency of dentinal tubules. This study compared the effectiveness of toothpaste containing Strontium Chloride, Novamine, Pro-Arginine in occluding dentine tubules along with comparision of those. Materials and Method: 45 freshly extracted teeth were randomly divided (15 each) into 3 groups: Group 1 15 Teeth treated with toothpaste containing Strontium Chloride. Group 2 15 Teeth treated with toothpaste containing Novamine Group 3 15 Teeth treated with toothpaste containing Pro-Arginine. Each specimen was brushed with the dentifrice slurries and examined under SCM. Result: The mean of occluded dentinal tubules on the dentin surface after brushing with three dentifrices were significant among them Pro-arginine group showed maximum occlusion. Conclusion: The present in vitro SEM study results revealed that: All the experimental agents– Strontium chloride, novamin, Pro- Argenine were effective in occluding dentinal tubules & the percentage (%) of occluded tubules was found to be highest for Pro- Argenine as compared to the other groups. Keywords: SCM, DH

Sequential Application of Calcium Phosphate and ε-Polylysine Show Antibacterial and Dentin Tubule Occluding Effects In Vitro

In this study, ε-polylysine and calcium phosphate precipitation (CPP) methods were employed to induce antibacterial effects and dentin tubule occlusion. Antibacterial effects of ε-polylysine were evaluated with broth dilution assay against P. gingivalis. CPP solution from MCPM, DCPD, and TTCP was prepared. Four concentrations of ε-polylysine(ε-PL) solutions (0.125%, 0.25%, 0.5%, 1%) were prepared. Dentin discs were prepared from recently extracted human third molars. Dentin discs were incubated with P. gingivalis (ATCC 33277) bacterial suspension (ca. 105 bacteria) containing Brain Heart Infusion medium supplemented with 0.1 g/mL Vitamin K, 0.5 mg/mL hemin, 0.4 g/mL L-cysteine in anaerobic jars (37 °C) for 7 days to allow for biofilm formation. P. g–infected dentin specimens were randomly divided into four groups: CPP + 0.125% ε-PL, CPP + 0.25% ε-PL, CPP + 0.5% ε-PL, CPP + 1% ε-PL. On each dentin specimen, CPP solution was applied followed by polylysine solution with microbrush and immersed in artificial saliva. Precipitate formation, antibacterial effects, and occlusion of dentinal tubules were characterized in vitro over up to 72 h using scanning electron microscopy. ε-PL showed 34.97% to 61.19% growth inhibition levels against P. gingivalis(P. g) after 24 h of incubation. On P. g-infected dentin specimens, DCPD + 0.25% ε-PL, and DCPD + 0.5% ε-PL groups showed complete bacterial inhibition and 78.6% and 98.1% dentin tubule occlusion, respectively (p < 0.001). The longitudinal analysis on fractured dentin samples in DCPD and TTCP groups revealed deeply penetrated hydroxyapatite-like crystal formations in dentinal tubules after 72 h of incubation in artificial saliva.

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.

Comparative Study of Technologies for Tubule Occlusion and Treatment of Dentin Hypersensitivity

This study aimed to evaluate the occluding/remineralization performance and resistance to acid attacks of the mineralization layer formed by a tooth-desensitizing gel containing amorphous calcium magnesium phosphate (ACMP) particles and compare it to six other desensitizing products available on the market. Similar comprehensive studies are few and there is especially a lack of studies that are up to date. A dentin-disc model was used for in vitro evaluation of the desensitizing toothpastes/gels. Application of the products was performed twice daily for seven days. One set of specimens were evaluated using scanning electron microscopy (SEM) directly after the final treatment and another set was evaluated after an acid challenge, exposing specimens to 2 wt% citric acid. The ACMP desensitizing gel was the only product resulting in complete occlusion by the formation of mineralized material on the dentin surface and inside the tubules. Particle deposition was dominant after treatment with the other desensitizing products, with little or no mineralization, resulting in partial occlusion only. Sensodyne Repair & Protect and Oral-B Pro-Expert showed the highest resistance toward acid attacks. Material inside the tubules remained relatively unaffected by acid attacks in all specimens. The results in this study indicated a great variability among the occluding agents in terms of occlusion and acid resistance of the mineralization layer. The high degree of occlusion and intra-tubular mineralization that could mitigate the effect of acid solubilization indicate that the ACMP desensitizing gel may be a superior option for the treatment of dentin hypersensitivity.

COMPARATIVE EVALUATION OF THE EFFECTIVENESS OF DESENSITIZING DENTIFRICE AND DENTAL LASER ON DENTINAL TUBULE OCCLUSION- AN INVTRO –SEM STUDY

Background: the present study aims to evaluate whether fluoro calcium phospho silicate (Biomin or Elzenes) or in combination with Diode laser has better dentinal tubule occlusion and can be suggested as a effective treatment modality for patients with dentinal hypersensitivity. The objectives of the study were -to evaluate effectiveness of Fluoro calcium phospho silicate on dentinal tubules occlusion, to evaluate effectiveness of Fluoro calcium phospho silicate and laser and to compare its effect with Fluoro calcium phosphosilicate alone and laser on dentinal tubule occlusion, and to evaluate the effectiveness of laser on dentinal tubule occlusion. In study setting, SEM analysis was done at Sophisticated test and instrumentation centre, Cochin University of Science and Technology (CUSAT), Kerala. 120 Dentine specimens were obtained from sound premolars extracted for orthodontic purpose from the patients of age group 13 to 40 years. All the teeth were stored in 0. 2% thymol at room temperature. In our study, Fluoro calcium phospho silicate (Biomin) showed an average results of 70.37% completely occluded tubules and 23.48% of partially occluded tubules compared to 2.68% and 28.43% in the control group. Conclusion: In our invitro study the treated groups the specimens brushed with combination group (Biomin and Laser) showed the highest percentage of tubule occlusion followed by Biomin alone and then Laser. Hence from the results, it can be stated that combination of Biomin and laser can be considered as the best effective method in office treatment modality for dentinal hypersensitivity because of its ability to occlude more tubules.. Keywords: Diode laser, Biomin or Elzenes