INTRODUCTION-

The goal of endodontic treatment is to create a sterile, bacteria-free environment inside the tooth as well as the periapical tissue to prevent or treat chronic periapical lesions. Post-operative pain is a common occurrence after endodontic therapy and irrigation plays an important role in disinfecting the root canal and removing bacteria in complex root canal systems. Optimal  endodontic access cavities have demonstrated better outcomes in terms of maintaining tooth integrity while still allowing sufficient access for cleaning and shaping the root canal system. 

Conventional needle irrigation is shown to be the most commonly employed irrigation with sodium hypochlorite but it fails to deliver intricate parts such as fins and ramifications of the root canal system. Irrigation activation modality which has gained recent trend is laser- activated irrigation where Er: YAG, Er, Cr: YSGG, Nd: YAG lasers have been studied extensively as irrigant modality for intracanal bacterial reduction. Diode Laser has been highly acceptable because of its high antibacterial effect and can aid in better irrigation in root canal treatment where conservation access has been performed. A combination of smear layer removal, bacterial reduction, reduced apical leakage are advantages of the laser and make it viable for endodontic treatment.

Sample Size Determination

The sample size to be  determined based on pilot study results using G*Power version 3.1 for Windows. 

Eligibility Criteria 

a. Inclusion Criteria

Systemically healthy patients (ASA–1) under the age group of 18- 65 years with a preoperative pain score ranging more than 5 cm on the VAS scale eliciting pain requiring primary root canal treatment in pulpal necrosis in mandibular molars are only considered.

b.Exclusion Criteria

Teeth with crown or root fracture, periapical cyst, resorption defects, calcifications, aberrant anatomy, sinus opening, sealer extrusion and previous evidence of endodontic treatment

 Setting and Location

The study participants will be recruited from the pool of patients who reported for treatment in the postgraduate section of the endodontics department of the college.

-Randomization

The randomization process to be carried out by a third person who will have  no participation in conducting the study. 

Treatment Procedure

Optimised  preparation of the access cavity to be made with the help of an Endo access bur 1. The canals will be initially scouted using ISO No.8 stainless steel K- file. Working length determination is done using an apex locator using an ISO No.10 stainless steel K-file.

Microbial analysis

Sample (S1) is to be collected after patency with a paper point placed in the canals for 60secs and sample (S2) is to be collected after disinfection protocol is followed using laser and PUI using paper points for 60secs. The samples will be placed in transport medium for further microbiological analysis using PCR. 

The bacterial species to be identified in PCR are 1. Prevotella intermedia ( B. P. F. A. Gomes et al) 2. Enterococcus faecalis(R Gnana Seelan et al) 3. Treponema denticola (J. F. Siqueira Jr et al) 

Irrigation Protocols

As mentioned above on page irrigation protocol will be Followed by the activation of irrigants,  canals obturation with 6% gutta- percha  using AH Plus / bioceramic sealer. The time of completion of the procedure and the postoperative pain scores of 4,  6, 12, 24, 48 & 72 h will be noted. 

Outcome measures

The primary outcome is the reduction of bacterial load will be assessed by the PCR and by level of postoperative pain at 4,  6, 12, 24, 48 & 72 h using the 10 cm VAS scale which will be recorded on a pain diary consisting of the hour and time of assessment.