الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 172 |  |  |
| | | from | 172 | | |
Abstract
The aim of the current study was to evaluate the effect of newly introduced irrigants of Herbal sources namely Chitosan and Curcumin regarding their Histological reaction, immunohistochemical reaction for their effect on TNFα, Anti- microbial activity with and without Gamma Radiation activation, Effect on dentin properties (Fracture resistance, Micro-hardness and Surface structure) and their Effect on the Post-operative pain.
For the histological reaction twelve male Sprague Dawley rats were used for the in-vivo experiments. They were treated according to the ethical guidelines for regulations of animal experiments of the Faculty of Dentistry, Ain Shams University. Subcutaneous tissue reactions to the irrigating solutions (Chitosan solution, Curcumin solution, 0.9% sterile saline and NaOCL [5.25%]) using a tuberculin syringe was done where 0.1mL of each root canal irrigant was injected subcutaneously into four circles and a needle of an empty syringe was introduced in the fifth circle, but no irrigant was injected (Control group). Evaluations were made 48 hours and 14 days after injection. In each examination period, six animals from experimental groups were sacrificed by cervical dislocation. The excised tissues samples were embedded in paraffin blocks and stained with Hematoxylin and Eosin with at least four microscopic fields that were containing connective tissue. The selected sections were then used to analyze the total number of infiltrating inflammatory cells for each treatment group after 48 hours and after 14 days.
Following deparafinization and rehydration of paraffin embedded sections, the sections were stained using rabbit polyclonal anti- tumor necrotizing factor alpha (Anti-TNFα) antibody. For the immune-stained sections, at least four microscopic fields showing the highest immune-positivity in each positive section were selected, and then they were evaluated and analyzed for the percentage of the TNF- α immune-positivity in the subcutaneous tissues.
For the antimicrobial effect; Fifty-three freshly extracted single-rooted human teeth with straight canals were selected, cleaned and the crowns were sectioned and the root lengths were standardized to approximately 16 mm. After root canal instrumentation they were contaminated by placing them in a suspension containing E.faecalis, E.coli and Candida albicans and incubated at 37 ℃ for 24 hours. After contamination for 21 days the roots were randomly divided into 6 groups with 8 roots each and biomechanical preparation was done up to size 50K files using the tested irrigants (NaOCl 5%, Chitosan, Chitosan that is Gamma irradiated, Curcumin and Curcumin irradiated with Gamma radiation). After the biomechanical preparation with the use of the irrigants microbiological sampling was done. The visible colonies were counted in every plate to determine the total colony forming unit (CFU) per ml of sample.
For the effect on Fracture resistance: Twenty four intact and healthy single-rooted human teeth were included in the study. The root specimens were then randomly distributed into three groups (n = 8) according to the irrigation solution used (Chitosan, Curcumin and Sodium hypochlorite 5%).The teeth were sectioned at the cement-enamel junction. After instrumentation the roots were embedded in acrylic resin using plastic cylinder. Specimens were placed on the lower plate of the universal testing machine and a compressive loading was applied vertically to the coronal surfaces of roots until fracture occurred. The load at which fracture occurred was recorded and expressed in Newtons(N).
For the Micro-hardness: Sixteen human non-carious single-rooted teeth were used in the study. De-coronation of all teeth transversally at cement-enamel junction to obtain 12 mm-length roots. After instrumentation each root was longitudinally sectioned in a bucco-lingual direction using automatic cutting machine. 24 samples without any surface defects were selected. The specimens were randomly divided into three test groups (n =8) according to the irrigant used (Chitosan, Curcumin and Sodium hypochlorite 5%). Each sectioned root was equally divided into three thirds representing coronal, middle and apical third. The dentin micro-hardness values of all samples were measured with Vickers micro-hardness.
For the Surface structure: Twenty four formed permanent human single rooted teeth were selected. All selected specimens were de-coronated at the cemento-enamel junction to establish a standardized tooth length of 12 ±1 mm. All specimens were then randomly divided into three groups (n= 8) according to final irrigating solution used (Chitosan irrigant 5ml/3min, Curcumin irrigant 5ml/3min and 5% NaOCl 5ml/3min). All roots were then sectioned longitudinally by using the precision cutter the Isomet 4000 in bucco-lingual direction. The coded specimens were measured using a caliper to determine the length from cementoenamel junction to the root apex to mark coronal, middle, and apical thirds. The specimens were then placed in a vacuum chamber for gold sputtering. Examination under SEM at X1500 magnification and digital photomicrographs were taken at the center of each third to visualize the dentin surface after application of final irrigants for the presence/absence of smear layer and visualization of the entrance to dentinal tubules. The cleaning of root canal walls were evaluated individually by two previously calibrated examiners who were blind to the irrigation regimens employed for each group. The four scores were (Score I: dentinal tubules completely opened, Score II: more than 50% of dentinal tubules opened, Score III: less than 50% of dentinal tubules opened and Score IV: all of the dentinal tubules covered with smear layer).
The effects of Chitosan and Curcumin as the final irrigation solutions in endodontic treatment on postoperative pain were evaluated. Twenty patients were randomly assigned to the two groups. Their age ranged from 18-55years. All root canal treatments were completed in a single session. After the irrigation protocol was completed using NaOCl, the final irrigation solutions were applied with a 30-gauge side-vented needle, 1 mm shorter than the working length, using the tested irrigants (Chitosan irrigating solution and Curcumin irrigating solution. Postoperative pain was evaluated using the visual analog scale (VAS). Postoperative pain was recorded on the 1st, 2nd, 3rd and 7th day.
The results of this study showed that Curcumin is considered to have an anti-inflammatory charactaristics. Curcumin and Chitosan showed the least tissue reaction thus can be considered biocompatible irrigants. Curcumin and chitosan showed antibacterial effect similar to that of NaOCl when activated by Gamma radiation while when used without activation the NaOCl showed the most antimicrobial effect. Regarding the effect on the mechanical properties it has been shown that they didn’t affect the fracture resistance. They also showed less effect on the Micro-hardness values of the root Dentin in comparison with the NaOCl with the chitosan showing the least effect on the Micro-hardness. The chitosan as an irrigating solution showed better removal of the smear layer and opening of the dentinal tubules followed by Curcumin while NaOCl effect was the least. Regarding the post-operative pain both newly introduced herbal irrigant didn’t show post-operative pain in most of the cases. Curcumin and chitosan as irrigating solutions show promising results regarding their biocompatibility and their effect on dentin properties yet NaOCl has proven to be having better antimicrobial activity unless they were activated by radiation where exposure of curcumin and chitosan solutions to gamma radiation increased their anti-microbial activity. Regarding the post- operative pain it has been shown that curcumin and chitosan have positive impact and decreased the post-operative pain.
Recommendations:
It’s recommended to use Chitosan and Curcumin as final irrigating solutions to help decrease the post-operative pain and help in removing the smear layer and opening of the dentinal tubules.