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Dentine Discs (dentine + disc)

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Medical Sciences100%

Selected Abstracts

Influence of the pulpal components on human dentine permeability in vitro

INTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2005
P. Puapichartdumrong
Abstract Aim, To examine the influence of the retained pulpal components on permeability of human dentine by monitoring drug diffusion. Methodology, Twelve intact dentine discs were prepared from freshly extracted human third molars. The dentine surface on the enamel side was etched with 10% polyacrylic acid for 30 s. The drug diffusion test was carried out before and after removal of the retained pulpal components. Each dentine disc was inserted between two plastic chambers; enamel- and pulpal-side chambers, which were filled with 0.05 mol L,1 naproxen sodium (NA) and phosphate-buffered saline (PBS), respectively. After 10 min, the solution on the pulpal-side chamber was collected to determine the concentration of NA using a spectrophotometer. To remove the retained pulpal components and residual NA, the pulp chamber of each disc was washed out with PBS and placed in an ultrasonic cleaner. After removal of these components and the residual NA, the drug diffusion test was repeated. The inner surface of the pulp chamber was observed using scanning electron microscopy (SEM) before and after the removal of the retained pulpal components. Results, The amount of NA that diffused through dentine into the pulp was significantly higher after the pulp chamber was washed out with PBS (paired t -test, P < 0.05). SEM observation demonstrated the presence of the retained pulpal components, odontoblastic layer and some parts of subodontoblastic zone, covering the surface of predentine. These components were removed after the pulp chamber was washed out with PBS followed by cleaning in an ultrasonic cleaner. Conclusions, The presence of retained pulpal components had a significant influence on drug diffusion through dentine discs. [source]

Bond strength of AH Plus and Epiphany sealers on root dentine irradiated with 980 nm diode laser

INTERNATIONAL ENDODONTIC JOURNAL, Issue 9 2008
E. Alfredo
Abstract Aim, To evaluate the bond strength of AH Plus and Epiphany sealers to human root canal dentine irradiated with a 980 nm diode laser at different power and frequency parameters, using the push-out test. Methodology, Sixty canine roots were sectioned below the cementoenamel junction to provide 4-mm-thick dentine discs that had their root canals prepared with a tapered bur and irrigated with sodium hypochlorite, ethylenediaminetetraacetic acid and distilled water. The specimens were assigned to five groups (n = 12): one control (no laser) and four experimental groups that were submitted to 980 nm diode laser irradiation at different power (1.5 and 3.0 W) and frequency (continuous wave and 100 Hz) parameters. Half of specimens in each group had their canals filled with AH Plus sealer and half with Epiphany. The push-out test was performed and data (MPa) were analysed statistically by anova and Tukey's test (P < 0.05). The specimens were split longitudinally and examined under SEM to assess the failure modes after sealer displacement. Results, The specimens irradiated with the diode laser and filled with AH Plus had significantly higher bond strength values (8.69 ± 2.44) than those irradiated and filled with Epiphany (3.28 ± 1.58) and the nonirradiated controls (3.86 ± 0.60). The specimens filled with Epiphany did not differ significantly to each other or to the control (1.75 ± 0.69). There was a predominance of adhesive failures at Epiphany,dentine interface (77%) and mixed failures at AH Plus,dentine interface (67%). Conclusions, The 980 nm diode laser irradiation of root canal dentine increased the bond strength of AH Plus sealer, but did not affect the adhesion of Epiphany sealer. [source]

Influence of the pulpal components on human dentine permeability in vitro

INTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2005
P. Puapichartdumrong
Abstract Aim, To examine the influence of the retained pulpal components on permeability of human dentine by monitoring drug diffusion. Methodology, Twelve intact dentine discs were prepared from freshly extracted human third molars. The dentine surface on the enamel side was etched with 10% polyacrylic acid for 30 s. The drug diffusion test was carried out before and after removal of the retained pulpal components. Each dentine disc was inserted between two plastic chambers; enamel- and pulpal-side chambers, which were filled with 0.05 mol L,1 naproxen sodium (NA) and phosphate-buffered saline (PBS), respectively. After 10 min, the solution on the pulpal-side chamber was collected to determine the concentration of NA using a spectrophotometer. To remove the retained pulpal components and residual NA, the pulp chamber of each disc was washed out with PBS and placed in an ultrasonic cleaner. After removal of these components and the residual NA, the drug diffusion test was repeated. The inner surface of the pulp chamber was observed using scanning electron microscopy (SEM) before and after the removal of the retained pulpal components. Results, The amount of NA that diffused through dentine into the pulp was significantly higher after the pulp chamber was washed out with PBS (paired t -test, P < 0.05). SEM observation demonstrated the presence of the retained pulpal components, odontoblastic layer and some parts of subodontoblastic zone, covering the surface of predentine. These components were removed after the pulp chamber was washed out with PBS followed by cleaning in an ultrasonic cleaner. Conclusions, The presence of retained pulpal components had a significant influence on drug diffusion through dentine discs. [source]

Effect of conditioning films and a novel anti-adherent agent on bacterial adherence to dentine

INTERNATIONAL ENDODONTIC JOURNAL, Issue 4 2001
A. Maglad
Aim,Adherence of bacteria to dentine is a prerequisite to infection of the root canal system, yet adherence of root canal bacteria to dentine is poorly understood. The aim of this study was to evaluate the effect of conditioning films and anti-adherent compounds on bacterial adherence to dentine. Methodology,Freshly extracted molar teeth were prepared and sectioned to give 225 discs of predetermined dimensions. The discs were allocated to two groups. Group 1 (n = 189) was divided into three subgroups (n = 63) and coated with one of three conditioning agents (artificial saliva, serum, or distilled water) prior to bacterial inoculation. Group 2 discs (n = 36) were treated with either a novel anti-adherent agent (PC1036, Biocompatibles) (n = 18) or distilled water (n = 18) prior to conditioning with artificial saliva. Monospecies bacterial biofilms were generated on the dentine discs by incubating them in brain heart infusion broth (37 gL,1) containing Streptococcus intermedius (Si), Enterococcus faecalis (Ef) or Lactobacillus fermentum (Lf) (originally isolated from infected root canals). The number of bacteria adhering to the discs in each of the groups was determined using standard serial dilution protocols. Additional discs were prepared under all conditions for scanning electron microscopy. Where appropriate, statistical analysis by one way anova, post hoc Bonferroni, and independent t -test were used. Results,Si adhered significantly better to dentine when conditioned with serum compared with artificial saliva (P = 0.005) or distilled water (P = 0.009). Conversely, Ef adhered significantly better to the control discs (distilled water) compared with serum conditioned discs (P = 0.016). The conditioning films had no effect on the adherence of Lf, which adhered to the dentine discs significantly less (P = 0.001) than either Si or Ef. The anti-adherent coating significantly reduced the number of Si adhering to the dentine compared with the control (P = 0.012). Conclusion,Given the importance of adherence in root canal infection it is conceivable that an anti-adherent compound, could be used to prevent bacterial recontamination of cavities or the root canal system. [source]

Effectiveness of propolis and calcium hydroxide as a short-term intracanal medicament against Enterococcus faecalis: A laboratory study

AUSTRALIAN ENDODONTIC JOURNAL, Issue 2 2009
Lama Awawdeh bds
Abstract The aim of this study was to investigate the antimicrobial activity of propolis-based intracanal medicament against Enterococcus faecalis using infected dentine models, and to compare its antimicrobial efficacy with that of the non-setting calcium hydroxide paste when used as a short-term medication for 1 and 2 days. A total of 50 dentine discs of 7-mm length was obtained from extracted human teeth. Five dentine discs were kept sterile to serve as a negative control. The remaining 45 were contaminated with E. faecalis and divided into two groups (n = 20) in addition to five discs that served as a positive control. The discs were treated as follow: 20 discs were filled with propolis, while the other 20 discs were filled with non-setting calcium hydroxide. Microbiological sampling was performed utilising sterile paper point, headstrom file and disc immersion. Results showed that propolis was significantly more effective than non-setting calcium hydroxide against E. faecalis after short-term application, which made comparison from this prospect unlevelled. The most effective microbiological sampling technique was abrading the lumen with headstrom file. Propolis is very effective as intracanal medicament in rapidly eliminating E. faecalis ex vivo. [source]