Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Dentin Permeability”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44Linked to original sources
PubMed2004

Diffusion of calcitonin through the wall of the root canal.

The aim of this study was to evaluate the in vitro diffusion of synthetic salmon calcitonin (CT), used as an intracanal medication, to the external root surface, with or without the presence of intact root cementum. Fifty-four human central incisors were used in the experiment, and were divided into two groups of 21 (test groups) and two groups of 6 teeth (control groups). After root canal preparation, 10 mul of calcitonin was inserted within the root canal chamber. The root was sealed and made externally impermeable. Specimens were then placed in tubes with saline solution buffered with phosphates and stored at 37 degrees C. The diffusion of calcitonin was measured after 1, 4 and 7 days. To count calcitonin present at the external media (PBS), ELISA test (an antigen-antibody reaction) was used. Results showed that there was calcitonin diffusion through dentin in all of the test samples. The absence of cementum increased the diffusion of calcitonin (p=0.05). The highest counts of CT were obtained on day 7 for groups with or without cementum - showing a direct relation between time and diffusion of the medication.

Animals↗
PubMedDate not supplied

Diffusion ability of endotoxin through dentinal tubules.

The aim of this study was to evaluate the ability of endotoxin to diffuse through dentinal tubules towards the cement and to observe the period of time needed for it to reach the external root surface. Thirty single-rooted human teeth had their crowns and apices removed in order to standardize the root length to 15 mm. Teeth were instrumented until #30 K-file and made externally impermeable with epoxy adhesive, leaving 10 mm of the exposed root (middle third). The specimens were placed in plastic vials and irradiated (60Co gamma-rays). Then, they were divided into 2 groups (n = 15): G1) Escherichia coli endotoxin was inoculated into the root canal of the specimens and 1 ml of pyrogen-free water was put in the tubes; G2) (control): pyrogen-free water was inoculated into the root canals and 1 ml of pyrogen-free water was put in each tube. After 30 min, 2 h, 6 h, 12 h, 24 h, 48 h, 72 h and 7 days, the water of the tubes was removed and replaced. The removed aliquot was tested for the presence of endotoxin. Considering that the endotoxin is a B-lymphocyte polyclonal activator, at each experimental period, B-lymphocyte culture was stimulated with a sample of water removed from each tube and antibody (IgM) production was detected by ELISA technique. The results of IgM production were higher in groups of 24 h, 48 h, 72 h and 7 days in relation to the other studied groups, with statistically significant differences (ANOVA and Tukey's test p < 0.05). Endotoxin was able to diffuse through the dentinal tubules towards the cement, reaching the external root surface after the period of 24 h.

Analysis of Variance↗
PubMedDate not supplied

Dentin penetrability evaluation of three different dyes in root-end cavities filled with mineral trioxide aggregate (MTA).

The purpose of this study was to evaluate the penetration of three dyes in MTA root-end fillings. In 30 single-rooted teeth, cavities for retrofilling were prepared with an ultrasound appliance and filled with MTA. The specimens were randomly assigned to three groups (n = 10) and immersed in the following solutions: 2% methylene blue (MET), 50% silver nitrate (NIT) and 0.2% rhodamine B (ROD). Two transversal slices (1 mm) of the retrofilling region were obtained and evaluated using the Image Tool 3.0 software to obtain a quantitative evaluation (in mm2) of the dye penetration around the retrofillings. Data were submitted to statistical analysis using Students t-test. The lowest degree of dye penetration was observed for the NIT group, in both slices (p < 0.05). Dye penetration was significantly larger in the ROD group when compared to the NIT group, in both slices (p < 0.05), and to the MET group, only in slice 1 (p < 0.05). Within the limitations of this study, it was concluded that the choice of dye could influence the penetration evaluation in root-end filling studies, and that the NIT had the lowest penetration capacity in the apical dentine.

Aluminum Compounds↗
PubMedDate not supplied

Effect of diode laser irradiation on the apical sealing of MTA retrofillings.

Apical sealing is essential for the success of paraendodontic surgery, so any procedure that may favor an adequate sealing of the apical remainder should be performed. The purpose of this study was to evaluate the influence of diode laser irradiation on the apical sealing of root-end cavities with MTA retrofillings. Root canals in twenty extracted human teeth were shaped with K-files and filled with gutta-percha. The apexes were cut off and root-end preparations were performed. The roots were divided randomly in 2 groups. Group 1 (ten specimens) was retrofilled with MTA. Group 2 was irradiated with diode laser, with 1 W for 20 seconds, on the apical surface and root end cavity before retrofilling with MTA. The specimens had their external surfaces impermeabilized with cyanoacrylate, except for the apical surface, and were then immersed in 1% rhodamine B dye for 72 h and placed in plaster stone. After that, the specimens were submitted to longitudinal abrasion until half of the root remained. The linear dye leakage was observed in these mid-roots between the root canal wall and retrofilling. The linear dye leakage was measured with Image Lab software, and the results were statistically analyzed with Student's t test. There were no statistically significant differences between the two groups (p > 0.05). The diode laser irradiation did not improve the apical sealing of MTA retrofillings under the conditions of this in vitro study.

Aluminum Compounds↗
PubMed1992

Root dentin morphology after different modes of citric acid and tetracycline hydrochloride conditioning.

The purpose of this study was to assess the effect of citric acid and tetracycline HCl application to dentin surfaces by a "passive dripping" or an "active burnishing" technique. Twenty dentin blocks were prepared from freshly extracted non-diseased human impacted third molars. The blocks were root planed and randomly assigned to two groups for treatment with either citric acid or tetracycline HCl. The duration of treatment was 30, 60, 120, or 240 seconds. Control blocks were treated with distilled water. After treatment the blocks were processed for observation and measurements in the scanning electron microscope (SEM). Application of either of the acid solutions resulted in removal of the smear layer. Measurements indicated a time dependent increase in the mean dentinal tubule orifice diameter ranging from 1.05 microns in control specimens to 3.18 microns after 4 minutes treatment (citric acid group). The increase in tubule diameter was significantly greater (P less than or equal to 0.01) for both citric acid treatment modalities than tetracycline HCl treatment. There was also a time dependent increase in the depth of penetration as measured by a trumpeting of the tubule profiles, and this penetration was significantly greater (P less than or equal to 0.01) after citric acid treatments. Passive or active application of the acids did not seem to have any major impact on the measurements or on the surface morphology. It was concluded that citric acid causes more extensive changes than tetracycline HCl and that the mode of application of the agent is probably not critical.

Acid Etching, Dental↗
PubMed2000

A comparative scanning electron microscopic study on the characteristics of demineralized dentin root surface using different tetracycline HCl concentrations and application times.

BACKGROUND: The use of demineralizing agents has been reported to enhance the degree of connective tissue attachment to denuded roots. Of the agents used, tetracycline HCI has received the most attention. METHODS: The purpose of this study was to evaluate and compare the SEM surface morphology of human root dentin following various concentrations and application times of tetracycline HCl. The surface characteristics were compared and the width of dentin tubule orifices were measured and analyzed. Twelve human teeth were collected and stored in distilled water after soft tissue removal using hand instruments. The apical third of each root was removed and remaining mid-root region was sectioned longitudinally through the root canal following removal of its cementum with a fine diamond bur. A total of 48 dentin specimens were randomly divided into 8 groups for conditioning at different tetracycline HCl concentrations, at 0, 10, 25, 50, 75, 100, 125, and 150 mg/ml. Application times for each group were 1, 3, and 5 minutes. Immediately following treatment procedures, the specimens were rinsed, fixed in GTA-PBF, dehydrated, and prepared for SEM. Each specimen was examined at 2 magnification values, representative fields photographed, and data tested by one-way ANOVA and paired t test statistical analysis. RESULTS: Our results indicate that the use of tetracycline HCl solution between 50 mg/ml and 150 mg/ml showed a statistically significant opening of dentin tubules. All tetracycline HCl groups at 1, 3, and 5 minutes show smear layer removal from the dentin surface. CONCLUSIONS: Dentin demineralization is not time dependent at all concentrations of tetracycline HCI.

Anti-Bacterial Agents↗
PubMed1990

[Bacterial penetration of bovine dentinal tubules. 1].

The penetration by bacteria through dentinal tubules was studied using a device that included portion of bovine anterior teeth. Strains of 4 genera, Streptococcus mutans, Lactobacillus casei, Staphylococcus aureus and Escherichia coli, were used for the experiment, and the effects of acid etching of dentin on the penetration of bacteria through the dentin was examined. The time required for penetration through dentinal tubules of acid-etched samples was shorter than that of unetched samples. The minimum time required for half the samples to become positive for bacterial penetration through dentin MPT50 was 4 hours for all strains chosen when the acid-etched dentin was the target. In non-acid etched samples, the MPT50 varied among the genera and ranged from 20 hours to 48 hours; the speed of penetration was Sta. aureus = L. casei greater than Str. mutans greater than E. coli. Observation under the scanning electron microscope indicated that the smeared layer was completely coated on the surface of the prepared cavity, and when bacterial penetration occurred, a portion of the smear layer on the dentin disappeared. In longitudinal sections, the penetration by the bacteria into the tubules was visible. From these results, it is suggested that the smeared layer have an important effects on bacterial penetration through these tubules.

Acid Etching, Dental↗
PubMed1998

Efficacy of self-etching primers containing carboxylic acid monomers on the adhesion between composite resin and dentin.

A study was conducted to examine the efficacy of carboxylic acid monomers as self-etching primers by measuring the tensile bond strengths between composite resin and dentin. Several kinds of carboxylic acid monomers, such as o-(N-methacryloyl amino)benzoic acid (o-MABA), m-(N-methacryloyl amino)benzoic acid (m-MABA), p-(N-methacryloyl amino)benzoic acid (p-MABA), 4-methacryloxy phthalic acid (4-MPA), 2-(N-methacryloyl amino) terephthalic acid (2-MATPA), and 5-(N-methacryloyl) amino)isophthalic acid (5-MAIPA), were prepared. 4-methacryloxyethyl trimellitic anhydride (4-META) was also used as a component of the self-etching primer. The DMSO solutions of these monomers were used as self-etching primers. The tensile bond strengths between composite resin and dentin were measured after 24 h immersion in water at 37 degrees C. When DMSO was used as a self-etching primer, the bond strengths were below 5 MPa. Among the monocarboxylic acid monomers, m-MABA gave the highest mean bond strength at 60 s application, and 5MAIPA gave the highest mean bond strength at 30 s application among the dicarboxylic acid monomers, although the differences among the values were not always significant. The smear layer was partially dissolved by treatment with the self-etching primer.

Acid Etching, Dental↗
PubMed1990

Dye penetration of the smear layer and fluoride application to the dentin surface.

A smear layer is formed after cavity or root canal preparation. The aim of the present study was to reinforce the dental surface in order to prevent the invasion of foreign irritants, by treating the smear layer with fluoride. Dentinal samples whose surfaces had been washed with water after the formation of a smear layer, and corresponding samples without washing, were examined by the dye penetration test, and the results were compared. Although there was no significant difference between the two groups of samples, dye penetration was suppressed by about 30% in washed samples, whereas the suppression was 20% in unwashed samples. When washed samples were treated with 1.0% SnF2, 10.0% SnF2, 7.5% Na2PO2F, 15% Na2PO2F, APF, 10 mM In(NO3)3, 100 mM TiF3, 50 mM TiF3, or 10 mM TiF3, samples washed after treatment with 1.0% SnF2 showed a dye penetration suppression of about 60% as a whole, in comparison with samples having no smear layer. Hardly any suppression of dye penetration was observed after treatment with other fluorides.

Acid Etching, Dental↗
PubMed1994

Effect of smear layer removal agent and/or fluoride on the surface of dentin.

A study was conducted to observe the effectiveness of an EDTA-based agent, Tubulicid Red, and a polyacrylic acid-based agent, Dentin Conditioner, for removal of the smear layer from a prepared dentin surface, with or without a fluoride dentin reinforcing agent, using the dye penetration test and scanning electron microscopy (SEM). Bovine mandibular first and second incisors were used. After removal of the enamel, the smear layer on the dentin surface was treated with 38% H3PO4, Tubulicid Red, Dentin Conditioner, 1% NaF, 1% SnF2, Tubulicid Red (including 1% SnF2), Dentin Conditioner (including 1% NaF) and Dentin Conditioner (including 1% SnF2). In the dye penetration test, Dentin Conditioner (including 1% SnF2) was the most effective agent for preventing dye penetration. SEM evaluation of the dentin surface after treatment with the smear layer removal agents and/or fluorides showed that the smear layer was removed by H3PO4 and Dentin Conditioner. However, dentinal plugs remained after treatment with Dentin Conditioner alone. The other agents left some layers on the dentin surface.

Acid Etching, Dental↗
PubMed1990

Adsorption of 2-hydroxyethyl methacrylate on dentin from aqueous solution.

The adsorption of 2-hydroxyethyl methacrylate (HEMA) on bovine dentin from aqueous solution was examined to clarify the priming effects of HEMA on dentin bonding. HEMA adsorption was characterized by: (1) slow attainment of equilibrium at higher concentrations (after 72 h); (2) a linear isotherm with a maximum possible adsorption, where an abrupt horizontal plateau occurred; (3) the large adsorption of ca. 2.5% by weight at the plateau; and (4) a vertical initial slope of the isotherm. The morphological difference between dentin powder surfaces before and after adsorption could not be determined. After heating, however, dentin powder which adsorbed HEMA was more resistant to demineralization with 6N HCl than the powder which did not adsorb. SEM examinations demonstrated that there was a demineralization-resistant dentin layer in tooth which adsorbed HEMA. The results indicated that HEMA infiltrated into intertubular dentin during adsorption.

Adsorption↗
PubMed1996

Endodontic disease: development and treatment.

Endodontic disease requires the involvement of micro-organisms. Microbial contamination of the pulp-dentine complex occurs in a number of different ways. The loss of integrity of teeth and the penetration of the pulp-dentine complex by a mixed microbial flora characterises the disease processes which can lead to pulpal and periradicular inflammation and infection. Endodontology is that part of dental science which deals with the biology of the pulp-dentine complex in health and disease, an understanding of which is a prerequisite to the provision of sound conservative care. The principles of endodontic treatment require the control of micro-organisms and potential nutrients by the microbial decontamination of teeth, the denaturing of protein and the sealing of dentine to prevent recolonisation.

Dental Pulp Diseases↗
PubMed2001

Pulp-dentin biology in restorative dentistry. Part 1: normal structure and physiology.

Considerable knowledge has accumulated over the years on the structure and function of the dental pulp and dentin. Some of this knowledge has important clinical implications. This review, which is the first of seven articles, will be limited to those parts of the normal structure and physiology of the pulp and dentin that have been shown to result in, or are likely lead to, tissue reactions associated with the clinical treatment of these tissues. Although certain normal structures will be highlighted in some detail, a basic knowledge of pulpal and dentinal development and structure is a prerequisite for an understanding of this text.

Biology↗
PubMedDate not supplied

Remineralization across the resin-dentin interface: in vivo evaluation with nanoindentation measurements, EDS, and SEM.

OBJECTIVE: The purpose of this study was to evaluate the in vivo remineralization of the possible non-resin infiltrated hybridoid layer between the hybrid layer and the subjacent dentin substrate using nanoindentation, energy dispersive x-ray spectroscopy microanalyses (EDS), and scanning electron microscopy (SEM) technologies. METHOD AND MATERIALS: Twenty Class V cavities were placed in healthy adult monkey teeth. Each cavity was total etched with 37% phosphoric acid for 60 seconds, rinsed, and air dispersed, and SA-Primer was applied to the collagen layer. Cavities were divided into two groups: In group 1, Protect Liner (low-viscosity resin) and Clearfil AP-X (resin composite) were placed per manufacturer's directions, and no bonding agent was placed on the acid-etched interface. In group 2, Clearfil Photobond (bonding agent) was applied, and Protect Liner and Clearfil AP-X were placed as in group 1. Teeth were observed at 7 days (control) and 6 months by nanoindentation, EDS, and SEM. RESULTS: Six-month data showed an increased nanohardness in areas 5 pm adjacent to the demineralized or partially demineralized dentin interface. Following treatment with a conventional adhesive system on the acid-etched interface (group 2), there were increased nanohardness and calcium EDS measurements in the substrate just below the resin-dentin impregnated layer. CONCLUSION: Our 6-month in vivo nanoindentation and EDS data demonstrate that the non-resin infiltrated zone becomes remineralized following adhesive resin treatment.

Acid Etching, Dental↗