Effect of Three Mechanical Systems on Removal of Endotoxins From Necrotic Teeth

Overview

The patients will be randomly assigned into two equal groups Group : OneShape Group: ProtaperNext Endodontics procedure steps: Patient will be anesthetized by using infiltration local anesthesia or nerve block according to the tooth location in mandibular or maxillary arch respectively. All caries will be removed, then isolation using rubber dam, the crown and surrounding structures will be disinfected with 30% H2O2( hydrogen peroxide) for 30 seconds, followed by 2.5% NaOCl for the same period of time and then inactivated with 5% sodium thiosulphate. 2- For the access cavity preparation, a sterile/apyrogenic high-speed diamond bur will be used in conjunction with manual irrigation with sterile saline. Before entering the pulp chamber, the access cavity will be disinfected according to the protocol described above. 2- Root canal length will be determined, by preoperative radiograph then (S1) will be taken by introducing a sterile/apyrogenic paper point #15/ 20 (5paper points) into the full length of the canal and left there for 1 minute. Then, the sample will be placed in an apyrogenic glass and stored in -20°. Then canal length will be confirmed by apex locator. 3- Cleaning and shaping will be done using either One shape or Protaper next rotary instruments in crown down preparation technique with the use of in an endodontic motor according to the manufacturer instructions, the canals will be thoroughly irrigated using 3ml of 2.5% Sodium hypochlorite between every subsequent instrument. Lab procedures to identify microorganisms

The patients will be randomly assigned into two equal groups Group : OneShape Group: ProtaperNext Endodontics procedure steps: Patient will be anesthetized by using infiltration local anesthesia or nerve block according to the tooth location in mandibular or maxillary arch respectively. All caries will be removed, then isolation using rubber dam, the crown and surrounding structures will be disinfected with 30% H2O2( hydrogen peroxide) for 30 seconds, followed by 2.5% NaOCl for the same period of time and then inactivated with 5% sodium thiosulphate. 2- For the access cavity preparation, a sterile/apyrogenic high-speed diamond bur will be used in conjunction with manual irrigation with sterile saline. Before entering the pulp chamber, the access cavity will be disinfected according to the protocol described above. 2- Root canal length will be determined, by preoperative radiograph then (S1) will be taken by introducing a sterile/apyrogenic paper point #15/ 20 (5paper points) into the full length of the canal and left there for 1 minute. Then, the sample will be placed in an apyrogenic glass and stored in -20°. Then canal length will be confirmed by apex locator. 3- Cleaning and shaping will be done using either One shape or Protaper next rotary instruments in crown down preparation technique with the use of in an endodontic motor according to the manufacturer instructions, the canals will be thoroughly irrigated using 3ml of 2.5% Sodium hypochlorite between every subsequent instrument. 4-After root canal preparation, NaOCl will be inactivated with 5 mL of sterile 5% sodium thiosulphate for 1 minute, which then will be removed with 5 mL of sterile/apyrogenic saline solution., which then will be removed with 5 mL of sterile/apyrogenic saline solution. second endotoxin sample (S2) will be taken from the root canals. (5 paper point size of the master cone). 5- After completion of instrumentation and irrigation, obturation will be done using size 30/ 0.4 taper gutta-percha cones and auxiliaries as needed using the modified single cone technique. Determination of Endotoxin Concentration Human endotoxin (ET) ELISA Kit will be used to measure endotoxin concentrations in the root canals before and after chemomechanical procedures.