Comparative Evaluation of the Effect of 970 nm Diode Laser With or Without N Acetyl Cysteine on Post Operative Pain After Endodontic Treatment in Teeth With Symptomatic Apical Periodontiti

1. To assess the postoperative pain after Endodontic treatment of mandibular molars with symptomatic apical periodontitis using N acetyl cysteine as intracanal medicament
2. To assess the postoperative pain after Endodontic treatment of mandibular molars with symptomatic apical periodontitis using 970nm diode laser .
3. To assess the postoperative pain after Endodontic treatment of mandibular molars with symptomatic apical periodontitis using 970nm diode laser with N acetyl cysteine .
4. To compare the incidence of postoperative pain after endodontic treatment of mandibular molar with symptomatic apical periodontitis using N acetyl cysteine , 970nm diode laser , 970nm diode laser and N acetyl cysteine as intracanal medicament
5. MATERIALS AND METHODS: 7.1 TYPE OF STUDY: An in vivo study 7.2 SOURCE: The study will be performed on mandibular molar. Study is to be conducted in Dept. of Conservative Dentistry and Endodontics, BDCH, Davangere

7.3 Materials and Equipment

• 4 round bur ( Mani ,Japan ) Endo Z bur (Dentsply Sirona , India)
• 10, #15 K files of 21mm length (MANI) Protaper gold (DENTSPLY SIRONA) of 21mm length Disposable syringes (BD Glide) Side vented needle (neoendo) Beakers 0.9% Normal saline (INFUTEC NS) Airotor handpiece (Rotomax) Canalpro cl2i endomotor (Coltene ,India) Apex locater (j morita root zx) 17% EDTA solution (DENTAL AVENUE) 2.5% NaOCl solution (SDFCL) N acetyl cysteine (Sigma Aldrich , Merck KGaA, Darmstadt, Germany) Sirolaser blue (Sirolaser blue , Dentsply Maillefer, Ballaigues, Switzerland) Cavit (Cavit-G; 3 M ESPE, St Paul, MN) EQUIPMENT
• X ray PSP scanner (PSP -SOREDEX DIGORA Optime) 7.2 Method of collection of data (including sampling procedure, if any): Simple random

METHODOLOGY Mandibular block anesthesia performed using local anesthetics solution 1.8ml 2% lidocaine with 1:80000 epinephrine. The procedure started after lip numbness was achieved. Occlusal reduction will be done followed by straight-line access cavity and the procedure was completed under rubber dam isolation. The working length was determined using an electronic apex locator (J morita), and Endomotor (Canalpro cl2i ,Coltene ,India) , Protaper gold (Dentsply Maillefer, Ballaigues, Switzerland) was used according to the manufacturer's instructions for cleaning and shaping .

A size 10 K-file was used to maintain apical patency, 2 mL 2.5% sodium hypochlorite was used between in-and-out pecking motions, and After instrumentation, The needle was advanced to a depth of 2-3 mm short of WL and the canal will be irrigated with 3 mL of 2.5% NaOCl. Final irrigation will be done with 5 mL of 17% EDTA for 1 min followed by a final rinse with 5ml of saline.

Randomization After that, patients were randomly assigned to one of the three groups based on the post operative therapy

ROOT CANAL INSTRUMENTATION

The patients will be randomly divided into 3 groups containing teeth in each group namely:

GROUP I(n=20): N acetyl cysteine GROUP II(n=20) : 970 nm diode laser Group II(n=20): 970 nm diode laser + N acetyl cysteine

Group I :

After the canals are dried with paper point N acetyl cysteine paste was applied as intra-canal medicament , and the access cavity was sealed using a temporary restorative material

GROUP II:

The final irrigation was performed , after the canals were dried with paper-points. During the laser treatment, both the operator and patient wore protective eyewear. Laser irradiation was applied using a 970-nm diode laser (Sirolaser blue , Dentsply Maillefer, Ballaigues, Switzerland) coupled with a 200-μm optical fibre. The settings were as follows: output power of 1.5 W in the pulsed mode irradiation for 10 s, followed by a 10-s pause, which comprised one cycle. This cycle was applied four times to each root canal. The power used was 1.5 W with a low frequency of 15 Hz. The optical fibre tip (length of 25 mm) was inserted at the working length. The root canals were then slowly (at a speed of 2 mm/s) irradiated from the apical to coronal using a continuous circling movement touching the dentinal walls in one cycle for each power. and the access cavity was sealed using a temporary restorative material.

GROUP III:

The final irrigation was performed as in the control group, and the canals were dried with paper points. During the laser treatment, both the operator and patient wore protective eyewear. Laser irradiation was applied using a 970-nm diode laser (sirolaser blue Dentsply Maillefer, Ballaigues, Switzerland ) coupled with a 200-μm optical fibre .The settings were as follows: power of 1.5 W and in the pulsed mode , irradiation for 10 s, followed by a 10-s pause, which comprised one cycle. This cycle was applied four times to each root canal. The power used was 1.5 W with a low frequency of 15 Hz. The optical fibre tip (length of 25 mm) was inserted at the working length. The root canals were then slowly (at a speed of 2 mm/s) irradiated from the apical to coronal using a continuous circling movement touching the dentinal walls in one cycle for each power.

Following the irradiation procedure, N acetyl cysteine paste was applied as intra-canal medicament , and the access cavity was sealed using a temporary restorative material, as in the control group

Subsequently, a temporary restorative material (Cavit-G; 3 M ESPE, St Paul, MN) was used to seal the access cavity.

At the time of the first visit, all the patients were given a VAS to rate their PP. A second appointment was scheduled for 7 d later. All patients who met the final inclusion criteria were given a pain chart to be completed to record the incidence of pain (yes/no), level of posttreatment pain and duration of pain (days).

The following variables were recorded:

1. Age
2. Sex
3. Tooth number
4. Number of canals
5. Preoperative pain on the VAS 7. Preoperative and postoperative percussion pain levels (on the 7th day) on the VAS 8. Pain level on the 8 hr ,24 hr, 48hr , 72hr \& 7 day 11. Analgesic intake after the procedure

At the second appointment, the ICM was removed from the root canals with final irrigation and using an F3/F2 file. The root canals were then obturated using the cold lateral condensation method with gutta-percha cones and AH Plus sealer (Dentsply Maillefer, Ballaigues, Switzerland). The coronal restoration was finished using a resin composite (Filtek Z250, 3 M ESPE, St. Paul, MN).