INFLUENCE OF TWO AGENTS DESENSITIZING TOOTHPASTES IN HYDRAULIC CONDUCTANCE DENTIN
Abstract
The aim of the study was to determine the effects of agents toothpastes on the hydraulic conductance of dentin desensitizers "in vitro". We selected 60 third molars healthy humans, recently extracted without occlusal contact, of patients between 15-30 years, which were cleaned, disinfected (Tymol 0.1% per 24 hours) and preserved at T ° atmosphere solution for a maximum of 14 days. The crowns were sectioned perpendicular to the tooth axis under abundant refrigeration, obtaining a disc of 1 mm +/-0.1 mm. thickness for each Crown. Disks were separated into the following three groups of treatment, of 20 discs each, which were brushings (brush electrical Oral-B Pro health Power) for 2 minutes only by your face occlusal with; A: Colgate ® Sensitive Pro relief with technology Pro arginine (Colgate-Palmolive, USA), B: Sensodyne ® quick-relief (GlaxoSmitheKline, UK), and C: distilled water as a negative control. The data were statistically analyzed by Kruskall Wallis and Mann Whitney tests. The results expressed in μl*cm-2*min-1cm*H2O-1 as stockings, separated by group were; A: 0,00650 (±0. 00384), B: 0,00800(±0,00472), c:0 and 03649(±0,03042). You could be concluded with the study that two dentin desensitizers agents present significant decrease in hydraulic conductance in dentin. Statistically significant differences were found between the group control and Sensodyne ® fast relief (p = 0, 000) and between group control and Colgate ® Sensitive Pro relief (p = 0, 000). There was no difference between the two toothpastes (p = 0, 317).
Supplementary resource (1)
ResearchGate has not been able to resolve any citations for this publication.
Dentine hypersensitivity (DHS) remains a worldwide under-reported and under-managed problem, despite making some dental treatments more stressful than necessary and having a negative impact on the patient's quality of life. This article is designed to build dental professionals' confidence and remove any confusion regarding the diagnosis, prevention and treatment of sensitive teeth caused by dentine hypersensitivity in those patients known to be at risk. There is a need for simple guidelines, which can be readily applied in general practice. However, it is also obvious that one strategy cannot suit all patients. This review describes a DHS management scheme for dental professionals that is linked to management strategies targeted at three different groups of patient. These patient groups are: 1) patients with gingival recession; 2) treatment patients with toothwear lesions; and 3) patients with periodontal disease and those receiving periodontal treatment. The authors also acknowledge the role of industry as well as dental professionals in a continuing role in educating the public on the topic of sensitive teeth. It is therefore important that educational activities and materials for both dental professionals and consumers use common terminology in order to reduce the possibility for confusion.
This review article provides practical, evidence-based guidance on the management of dentine hypersensitivity for dental professionals covering diagnosis, prevention and treatment. Sensitivity associated with gingival recession, toothwear and periodontal disease and periodontal treatment are specifically addressed in the article.
The in vitro effects of two commercial sensitivity relief dentifrices, one containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride as sodium monofluorophosphate (MFP), and the other containing 8% strontium acetate and 1040 ppm fluoride as sodium fluoride, in occluding dentin tubules and reducing dentin fluid flow were compared in a blinded study using hydraulic conductance (Flodec).
Human dentin segments were cut from extracted molars, mounted on acrylic blocks, etched, and connected to a Flodec to measure hydraulic conductance. Segments were divided into two groups (n = 6) and treated for one minute with either the arginine/calcium carbonate dentifrice or the strontium acetate dentifrice. The blocks were rinsed, connected to the Flodec, and the conductance was measured. Blocks were rinsed again and incubated in phosphate-buffered saline (PBS) for at least two hours before the next treatment. The cycle was repeated for a total of three treatments (one using a fingertip and the next two using a toothbrush). After the third treatment, the blocks were incubated in PBS overnight and conductance was re-measured. The two groups were further divided into three sets of two segments each, which were challenged for one minute with either 6% citric acid, orange juice, or grapefruit juice.
The hydraulic conductance study showed that the dentifrice containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride provided a significantly higher percentage reduction in fluid flow immediately after fingertip application, as well as after two brushing cycles, compared to the dentifrice containing 8% strontium acetate and 1040 ppm fluoride. After various acid challenges, the percentage reduction in fluid flow of dentin treated with the arginine/calcium carbonate dentifrice remained significantly higher than that of the strontium acetate dentifrice. These results are highly consistent with the results from an independent clinical study which showed that the arginine/calcium carbonate dentifrice provided dentin hypersensitivity relief immediately after direct topical application with a fingertip and massage for one minute per sensitive tooth, whereas the strontium acetate dentifrice did not.
Based on this in vitro hydraulic conductance study, the dentifrice containing 8.0% arginine, calcium carbonate, and 1450 ppm fluoride was significantly more effective in reducing fluid flow through dentin tubules as a result of occlusion than the dentifrice containing 8% strontium acetate and 1040 ppm fluoride. Further, the superior occlusion obtained with the arginine/calcium carbonate dentifrice was resistant to acid challenge.
Dentine hypersensitivity is a condition that is often present in individuals, leading them to seek dental treatment. It has been described as an acute, provoked pain that is not attributable to other dental problems. Its actual prevalence is unknown, but it is interpreted as very unpleasant by individuals. Several therapeutic alternatives are available to manage dentine hypersensitivity, involving both in-office treatment and home-use products. The aim of this literature review was to evaluate self-care products for managing dentine hypersensitivity. Among the products available, dentifrices and fluorides are the most studied self-care products, with positive effects. However, a high percentage of individuals is affected by the placebo effect. Among dentifrices, those containing potassium salts seem to be the most promising. Dental professionals need to understand the advantages and limitations of these therapies and use this knowledge in a positive approach that might help in decreasing dentine hypersensitivity among patients.
Dentine hypersensitivity occurs when patent dentinal tubules are subjected to external stimuli, with pain being reduced by products that occlude tubules. This study compared the efficacy of a recently developed arginine-containing dentifrice, two established strontium-based products, and a fluoride control to occlude tubules when subjected to acid challenge. Dentine specimens with patent tubules were divided into four groups that were treated with a slurry consisting of one of the pastes mixed with stimulated human saliva. Treated specimens were further subdivided and soaked in 0.3% citric acid for 10 s, 30 s, 2 min, 5 min or 10 min. Tubule occlusion on representative scanning electron microscopy images was scored by blind review. All three desensitizing pastes offered good tubule occlusion, which was maintained to varying degrees following acidic challenge. After immersion in acid for 10 and 30 s, the strontium acetate- and arginine-containing pastes almost fully occluded tubules, but only the strontium acetate paste retained this level of occlusion after immersion in acid for 2 min, with strong statistical evidence that this paste occluded more tubules than the other pastes after immersion in acid for 2 or 5 min. This suggests that strontium acetate pastes may be the most effective at reducing dentine hypersensitivity.
The influence of dentin permeability on transdentinal LED light propagation should be evaluated since this kind of phototherapy may further be clinically used to stimulate the metabolism of pulp cells, improving the healing of damaged pulps. This study evaluated the influence of the dentin permeability on the transdentinal LED light (630 nm) transmission. Forty-five 0.5-mm-thick dentin disks were prepared from the coronal dentin of extracted sound human molars. An initial measurement of transdentinal LED light transmission was carried out by illuminating the discs in the occlusal-to-pulpal direction onto a light power sensor to determine light attenuation. The discs were treated with EDTA for smear layer removal, subjected to analysis of hydraulic conductance, and a new measurement of transdentinal LED light transmission was taken. Spearman's correlation coefficient was used for analysis of data and showed a weak correlation between dentin permeability and light attenuation (coefficient = 0.19). This result indicates that higher or lower dentin permeability does not reflect the transdentinal propagation of LED light. Significantly greater transdentinal propagation of light was observed after treatment of dentin surface with EDTA (Wilcoxon test, p < 0.05). According to the experimental conditions of this in vitro study, it may be concluded that dentin permeability does not interfere in the transdentinal LED light transmission, and that smear layer removal facilitates this propagation.
Soares DGS, Ribeiro APD, Sacono NT, Coldebella CR, Hebling J, de Souza Costa CA. Transenamel and transdentinal cytotoxicity of carbamide peroxide bleaching gels on odontoblast-like MDPC-23 cells. International Endodontic Journal, 44, 116–125, 2011.
Aim To evaluate the transenamel and transdentinal cytotoxicity of bleaching gels based on carbamide peroxide (CP) on odontoblast-like cells after different contact times of the products with enamel.
Methodology Enamel/dentine discs were obtained from bovine incisors and placed in artificial pulp chambers. Bleaching gels containing 10% or 16% CP were applied for 8 h day−1 on the enamel side of the discs during periods of 1, 7 or 14 days. Deionized water and artificial saliva served as controls. The extracts (culture medium plus bleaching gel products that diffused through the discs) were collected and applied on previously cultured MDPC-23 cells for 1 h. Cell metabolism was evaluated by the MTT assay, and the data were analysed statistically by one-way anova and Tukey’s test (α = 0.05). Cell morphology was analysed by SEM.
Results There was no significant difference (P > 0.05) between the controls and the groups bleached with 10% CP gel. In the groups bleached with 16% CP gel, however, cell metabolism decreased significantly (P < 0.05) by 40.32%, 30.16% and 26.61% at 1, 7 and 14 days, respectively. There was no significant difference (P > 0.05) between 1, 7 or 14 applications of the gels for either of the CP concentrations.
Conclusion Regardless of the number of applications on an enamel surface, the 10% CP bleaching gel did not cause transenamel and transdentinal cytotoxicity to the MDPC-23 cell cultures. However, diffusion of products from the 16% CP gel through enamel and dentine and cytopathic effects to the pulp cells occurred even after a single application of this product on enamel.
It has been demonstrated that chlorhexidine digluconate (CHX) is capable of eliminating bacteria that may remain lodged in dentin after mechanical caries removal. In addition, the use of CHX on acid-etched dentin before adhesive system application delays the resin-dentin interface degradation, maintaining the integrity of the adhesive restorations. Despite these advantages of using CHX in restorative dentistry, when applied on dentin, this chemical agent may diffuse across dentinal tubules to cause toxic effects to the pulp cells. The aim of this study was to evaluate the transdentinal cytotoxic effects caused by different concentrations of CHX gels applied on acid-conditioned dentin substrate. Dentin discs (0.2-mm and 0.5-mm thick) were cut from human third molars and mounted in artificial pulp chambers. Odontoblast-like MDPC-23 cells (50,000 cells/cm(2)) were seeded on the pulpal side of the discs, and the carbon polymer gel (natrosol) with different CHX concentrations (0.12, 0.2, 1, and 2%), 35% phosphoric acid, or pure natrosol were applied on the occlusal side of the discs, forming six treatment groups (n = 10 discs/thickness). The dentin discs in the control group (n = 10 discs/thickness) did not receive any treatment. In each group, cell metabolism was analyzed by the methyltetrazolium assay (n = 8/thickness), and cell morphology was assessed by scanning electron microscopy (n = 2/thickness). Statistical analysis showed that CHX gels had a dose-dependent toxic effect on the odontoblast-like cells. Cell metabolism decreased by 12.8, 14.6, 18.3, 26, 13.7, and 10.5% for the 0.5-mm-thick dentin discs and 23, 26.3, 28.1, 34.5, 22.5, and 19.4% for the 0.2-mm-thick dentin discs treated with 0.12% CHX, 0.2% CHX, 1% CHX, 2% CHX, H(3)PO(4), and pure natrosol, respectively. According to the experimental conditions of the current investigation, it may be concluded that the application of natrosol gel with different concentrations of CHX on acid-conditioned dentin causes mild transdentinal cytotoxic effects to the MDPC-23 cells in a dose-dependent manner. Dentin acted as a biological barrier against CHX diffusion, and this effect was directly related to dentin thickness.
To evaluated the transdentinal diffusion and subsequent cytotoxicity of self-etching adhesives on odontoblast-like cells.
Sixty dentin disks (0.4-mm thick) were produced from human molars and divided into six groups (n = 10). The dentin disks were placed in in vitro pulp chambers where MDPC-23 cells were planted on 0.28 cm(2) of exposed dentin on the pulpal side. The adhesives Clearfil SE Bond (CSE), Clearfil Protect Bond (CPB), Adper Prompt (PR), and Xeno III (XE) were applied on the occlusal side. Single Bond (SB) was used as positive and phosphate buffer solution (PBS) as negative control. The cytotoxicity was measured by MTT assay and cell characteristics were assessed by SEM. The transdentinal diffusion was qualified by GC/MS.
Kruskal-Wallis and Mann-Whitney tests demonstrated a significant difference among the adhesives and PBS. Cellular viability reduction promoted by the self-etching systems was lower than that of SB (53.1%), except for CSE. Cell metabolism was reduced in 47.8%, 42.1%, 28.0%, and 46.5% for CSE, CPB, PR, and XE, respectively. HEMA was identified as the main diffused component.
Components from all investigated self-etching adhesive systems were able to diffuse through the dentin resulting in significant reduction of the cellular metabolism.
A technique is described which permits measurements of the ease with which fluid permeates dentin. This value, the hydraulic conductance of dentin, increased as surface area increases and/or as dentin thickness decreases. It increased 32-fold when dentin was acid etched due to removal of surface debris occluding the tubules.
The resistance to fluid movement through dentine was analysed in terms of 3 resistances placed in series: (1) surface resistance due to the presence of debris occluding dentinal tubules, (2) an intratubular resistance due to mineralized nodules and internal irregularities within the tubules, (3) a pulpal resistance due to the presence of odontoblast processes and cell bodies within the tubule. Surface resistance accounted for 86 per cent of the total resistance. In addition, the resistance to fluid movement varied with the direction of pressure application being lowest in the enamel to pulp direction.