7.1 Need for the study :

·      One of the most important aspects of endodontic treatment is pain management. According to a systematic review, the frequency of endodontic postoperative pain is between 3% and 58% of patients. 

• Post-operative pain is usually attributed to mechanical, chemical and microbial causes, of which microbes are conceivably the prime aetiologic agents. Although chemomechanical treatment is efficient in reducing intracanal bacterial load, the bacteria may survive and remain in inaccessible parts of the root canal system.^[1]
• Disinfection of the three-dimensional tubular root canal network is one of the prime objectives of root canal treatment. The use of mechanical instrumentation alone cannot sufficiently debride and clean this complex tubular network.^[2]
• Considering the weaknesses of common irrigants in root canal treatment, in recent years, new methods such as lasers have been introduced to effectively disinfect the root canal system.^[2]
• It is conceivable that irrigant delivery methods which provide continuous replenishment of root canal irrigant may be more efficient. Recent studies have also shown better efficacy of continuous ultrasonic irrigation as compared to syringe irrigation.^[1]
• Combination therapy using various medicaments or irrigation solutions together with lasers has been reported to be more effective for canal disinfection.Among different types of the lasers, the diode laser is the most desirable type, due to the properties such as high penetration depth into the dentinal tubules and proper antibacterial effect.^[2]
• However, there appears to be no study assessing and comparing the effect of irrigant activation using continuous ultrasonic irrigation device, laser agitated irrigation (LAI) and laser irradiation using diode laser on post-operative pain. This randomized controlled trial was, therefore, designed to compare the post-operative pain after the use of continuous ultrasonic irrigation, laser agitated irrigation and laser irradiation using diode laser. The null hypothesis tested was that there is no significant difference in post-operative pain with the use of any of the above mentioned irrigation protocols.

7.2  Review of Literature :

1.     M Middha et al^[1] (2017) Carried out a study to evaluate the effect of contiuous ultrasonic irrigation on post-operative pain in mandibular molars with non-vital pulps. 70 patients were randomly allocated to one of two groups, continuous ultrasonic irrigation (CUI) (n=35) and syringe irrigation (SI) (n=35). The CUI group received irrigant activation using Proultra Piezoflow ultrasonic needle as the final irrigation protocol, while in the SI group, the final irrigation  was performed using 27 gauge needle. Post operative pain using a visual analogue scale  and analgesic intake were recorded every day for 7 days. The study revealed that there was significant decrease in pain in the CUI group after 24 hours.

2.     Dina A. Morsy^[5] et al (2018) Carried out a study aimed to investigate the ability of the diode laser (DL) to decrease postoperative pain and achieve root canal sterility. In this study, 56 patients were randomly divided into two groups (n=28). All patients were treated with two vists of conventional root canal treatment with ProTaper Universal. The DL group: root canals were irradiated with 200μm fiber optic at both visits; the control group (Endo): the DL fiber was placed in root canal with no activation. Bacterial samples were collected from all cases at each step of the treatment. Pain levels were evaluated using numerical rating scale preoperatively, and after 6, 12, 24, 48 hours and 7 days. The results revealed  statistically significant lower pain levels in DL group compared with the Endo group at all time intervals. 

3.     PR Attiguppe^[3] et al (2018) Carried out a study to compare the efficacy of latest advancements in disinfection techniques using diode laser namely direct laser irradiation, photodynamic therapy and laser activated irrigation using sodium hypochlorite. Sixty freshly extracted primary teeth either single or multi-rooted teeth with two third of their root length intact were collected. Instrumentation was completed to size 30 H-file. Teeth were randomly divided into Group 1- Direct Laser- irradiation, Group 2 - Photodynamic therapy; Group 3- Laser activated irrigation with 2.5% NaOCl. The tooth specimens were inoculated with Enterococcus faecalis. The bacterial colonies were counted preoperatively. Laser irradiation was performed for all groups in accordance to the groups each tooth belonged to. Postoperatively the bacterial colonies were counted. One-way Analysis was applied to compare bacterial count at baseline and post-test between three groups. Tukey’s post-hoc test was applied for pairwise comparison between groups. Paired t-test was applied to compare the mean baseline bacterial count with post-test mean bacterial count. Statistically significant difference between results of Group 1 and Group 2 and also between Group 1 and Group 3 was found (p-value≤ 0.001). They also concluded that disinfection strategies using diode laser by techniques gives promising results.

4.     Shaktawat AP^[2] et al (2018) carried out a study in which the aim was to evaluate and compare the antimicrobial efficiency of different irrigating solutions against Enterococcus faecalis with or without the use of 980 nm diode laser in infected root canals. A total of 100 freshly extracted human singlerooted teeth were divided into three experimental groups (n = 30) and one control group (n = 10). Experimental group was subdivided into two subgroups A and B (n = 15), whereas control group was subdivided into positive and negative controls (n = 5). After access cavity preparation, the root canals were prepared using ProTaper rotary instruments. A volume of 5 ml of 5.25% sodium hypochlorite and 17% Ethylenediaminetetraacetic acid, 1.2 ml of 2% chlorhexidine gluconate, and 2 ml of neem solution was used for irrigation in Group I, II, and III, respectively. E. faecalis (ATCC 29212) was inoculated into each canal of experimental groups and incubated for 2 weeks under aerobic conditions at 37°C. In all the subgroups B, laser irradiation was performed, whereas, in subgroup A, no laser irradiation was done. In negative control, E. faecalis was not inoculated in samples, but in positive control, E. faecalis inoculation and incubation procedure was followed. With circumferential filing using #40 reamer, dentinal chips were collected using sterile paper points, vortexed in sterile saline, was then applied to UTI Hicrome agar culture plates and incubated at 37°C for 48 h. The cfu/ml for each plate was calculated using a bacterial colony counter. The data obtained were subjected to statistical analysis using SPSS software version 20.0.The study showed that the least number of bacterial cfu/ml was observed in Group IB. The order of bacterial colony count (cfu/ml) was observed as Group IB

5.     Raghad Hmud^[4] et al (2010)They did a study to see if diode laser endodontic treatments such as disinfection or the generation of cavitations cause deleterious thermal changes in radicular dentin.This study assessed thermal changes in the root canal and on the root surface when using 940 and 980 nm lasers at settings of 4 W/10 Hz and 2.5 W/25 Hz, respectively, delivered into 2000-mm fibers to generate cavitations in water. The root surface temperature in the apical third was recorded, as was the water temperature in coronal, middle, and apical third regions, by using thermocouples placed inside the canal. Lasing was undertaken with either rest periods or rinsing between 5-second laser exposures. They concluded that diode laser parameters that induce cavitation do not result in adverse thermal changes in radicular dentin.

7.3 Aim of Study :

To Evaluate and Compare the post operative pain in symptomatic non vital teeth with the use continuous ultrasonic irrigation, laser activated irrigation and laser irradiation using diode laser.

7.3  Objectives of the Study :

1      To evaluate the post-operative pain in patients with continuous ultrasonic irrigation with 3% NaOCl  irrigant followed by chlorhexidine final flush.

2      To evaluate the post-operative pain in patients with Laser Activated Irrigation (LAI) using Diode laser and 3% NaOCl as the canal disinfection procedure followed by chlorhexidine final flush.

3      To evaluate the post-operative pain in patients with laser irradiation using Diode Laser (DL) as canal disinfection procedure followed by chlorhexidine final flush.

4      To compare the incidence of post-operative pain in patients treated with continuous ultrasonic irrigation, LAI and laser irradiation using DL.

Materials and Methods :

8.1   Source of data :

·      Type of study : Randomized controlled clinical trial

·      In-vitro/in-vivo/survey : In-vivo study

·      Source from where the cases, patients, subjects or study material will be selected :

Patients will be selected from the Department of Conservative Dentistry and Endodontics, Dr. D. Y. Patil Dental College and Hospital, Pimpri, Pune according to inclusion and exclusion criteria.

·      Name and place where the study will be conducted :

Department of Conservative Dentistry and Endodontics,

Dr. D. Y. Patil Dental College and Hospital, Pimpri, Pune.

8.2  Method of data collection :

·      Sampling technique used: Convenient sampling

·      Sample size : 63

·      Size of each group : 21

Group I : Ultrasonic activated irrigation with 3% NaOCl 

Group II : Laser activated irrigation using 3%NaOCl using diode laser

Group III : Laser irradiation using diode laser after 3% NaOCl irrigation.

Patients will be selected on the basis of following criteria :

1.     Inclusion Criteria : 

a)     Patients of 18 years and above.

b)    Patients  with symptomatic necrosed teeth of singled rooted teeth needing a primary endodontic treatment having periapical radiolucency not more than 2mm.

2.     Exclusion Criteria :

a)     Patients with systematic diseases or allergic reactions

b)    Patients who are on medication.

c)     Previous root canal treatment

d)    Swelling or sinus tract

e)     Severe periodontal disease

f)     The presence of periodontal pockets more than 3 mm in the corresponding tooth

g)    Periapical radiolucency of not more than 2mm

h)    Teeth having calcified root 

i)      Teeth with immature apex

For clinical studies, it is important to state that prior to starting the research work, written informed consent will be taken from the respective authorities, hospitals, patients/subjects, parents/caretakers.

Consent is required, since the study is a randomized controlled clinical trial.

a)    Enlist the materials/instruments/armamentarium to be used in the study 

Materials used :

1)    Lignocaine 1:200000 adrenaline (Lignox^TM, Warren, Mumbai, India)

2)    Normal Saline (autoclaved)  (Braxter^TM)

3)    EDTA (RC Help, PRIME^TM dental products Pvt Ltd)

4)    3% NaOCl  (PRIME^TMdental products Pvt Ltd), 

5)    Chlorhexidine liquid, (DentaClor^®)

6)    Paper points (Dentsply^TM)

7)    AH – Plus sealer (PRIME^TM  Dental Product, Mumbai, India)

8)    Gutta Percha cones (DiaDent),

9)    Etching gel ( Restorite Etching Gel, PRIME^TM  dental products Pvt Ltd)

10) Bonding agent (3M ESPE Adper^TM  Single Bond 2), 

11) Composite  resin (3M ESPE Filtek^TM Z350 XT Universal Restorative),  

Instruments used :

1)    Mouth mirror (GDC^®)

2)    Probe (GDC^®)

3)    Tweezer (GDC^®)

4)    Stainless steel Kidney tray

5)    Syringe  (Dispovan^TM)

6)    NSK Air rotor Handpiece (NSK^TM, Japan)

7)    Round diamond point (BR 40: Mani, Inc., Tochigi, Japan)

8)    Non-end cutting bur (Diaburs^TM, PRIME^TM Dental Products, Mumbai, India) 

9)    Endodontic explorer – DG16 (Dentsply^TM Maillefer, Ballaigues, Switzerland)

10)  Stainless steel K  and H files (#10, #15) (Mani^TM, Inc., Tochigi, Japan).

11) ProTaper Next Rotary Files (Dentsply, Sirona, USA) 

12) Gates Glidden drills # 2 and # 3 (Mani^TM, Inc., Tochigi, Japan).

13) Lentulospiral # 40 (Mani^TM, Inc., Tochigi, Japan).

14) Spreaders # 15 - # 40 (Mani^TM, Inc., Tochigi, Japan).

15) GP Cutter (GDC^®)

16) Burner

17) Ball burnisher (GDC^®)

18) Disposable Applicator brush (3M- ESPE), 

19) Composite resin restorative Instruments (GDC^®),

Equipments used :

1)    Dental Dam Kit (HYGENIC, H02778) ,

2)    Endodontic Rotary motor (X-Smart Endodontic Rotary Motor (Complete Kit) Dentsply Sirona,USA)

3)    RVG machine (Kodak 5100)  

4)    Diode laser (Epic X, BIOLASE)

5)    Ultrasonic irrigation tips (Satelec Sonofile K-File Ultrasonic Tips, Dentsply Sirona,USA)

METHOD :

·      63 patients requiring root canal treatment reporting to the Department of Conservative and Endodontics at Dr. D.Y. Patil Dental College and Hospital will be selected as per the inclusion and exclusion criteria mentioned.

·      Each subject will be made aware of the procedure and a written consent form will be taken from each subject to participate in the study.

First Visit:

• At the first visit, all patients will record their pain level preoperatively using a numerical rating scale (NRS). 
• The teeth will be locally anaesthetized with lignocaine with 1:200000 adrenaline (Lignox^TM, Warren, Mumbai, India)
• The teeth will be properly isolated with rubber dam with Dental Dam Kit (HYGENIC, H02778) .
• An access cavity preparation will be performed. 
• Patency of the root canal will be obtained using stainless steel hand k- files size #10 or #15 (MANI, Tochigi, Japan). 
• Working length will be determined using an electronic apex locator then confirmed with intraoral periapical radiograph.
•  Mechanical preparation will be performed with the ProTaper Next rotary files for all the cases. 
• 3% sodium hypochlorite will be  used for irrigation and recapitulation will be done between each file and the next using a 26-gauge needle.
• According to the randomization and sequence generation, the patients will be allocated into three groups (n = 11 per group).

Group I: Continuous Ultrasonic Irrigation group:

§  In the CUI group, the needle will be operated using Satelec P5 Piezoelectric Ultrasonic Unit (Acteon, Mount Laurel, NJ, USA) at power setting of 5. 

§  The stopper on the PiezoFlow needle will be set 1 mm short of binding in the canals, but no more than 75% of the working length.

§  A syringe containing 15 mL of 3% NaOCl will be attached to the Piezoflow activation needle and the inactive needle will be inserted in the canal, and irrigant flow will be started before the activation. 

§  During activation, the needle will be moved up and down passively in the canal, while maintaining the insertion depth to the stopper setting. 

Group II: Laser Activated Irrigation group:

§  The root canal  will be filled with 3% NaOCl before the laser fiber be placed in its starting position 2 mm short of the anatomical apex.

§  Root canals  will be initially irrigated with 3% NaOCl and will be activated with diode laser  of 940 nm will be used at a panel setting of 4 W/10 Hz,  from the terminal end of a 200-µm diameter plain-ended endodontic fiber for a 5 second period.   

§  The fiber will be held in a fixed position, this will be followed by activation during which it will slowly be dragged at a speed of approximately 2 mm/ sec in a way that the irrigant in the canal will be activated from the apical to the coronal portion, in a helicoidal movement touching the canal walls. The irrigation activation protocol will be of 5 sec of activation followed by a 10 sec pause, which will be performed four times for each tooth. 

§  This will be done to ensure equal diffusion of light inside the root canal lumen. 

Group III: Laser irradiation with diode laser group: 

§  The root canals will be irradiated with 940 nm diode laser coupled with optical fiber 200 μm with setting 1.2-watt power, in pulsed mode. 

§  The irradiation protocol will be of 5 sec irradiation followed by a 10 sec pause, which constituted one lasing cycle. 

§  The lasing cycle will be performed four times for each tooth. 

§  The tip was positioned 1 mm short of the apex. 

§  This will be followed by activation during which it will slowly be dragged at a speed of approximately 2 mm/ sec in a way that the root canals were irradiated from the apical to the coronal portion, in a helicoidal movement touching the canal walls. 

§  This will be done to ensure equal diffusion of light inside the root canal lumen. 

• 17% EDTA  will be used at the end of the procedure to remove the smear layer, followed by irrigation with saline.

·      At the end of the first visit, all patients will be instructed to record pain level on the VAS pain scale chart after 24, 48 hours and after 7 days. 

·      The patients will be instructed to submit the pain scale charts after the 7th day.

·      Rescue medication will be given if the patient complains of pain, such as Combiflam^® or Paracetamol tablets (Dolo^®-500) of the recommended doses. In case of severe pain, Keterol^TM DT will be prescribed. 

Second visit:

• In the second visit, one week later; the canals of all the three groups will be re accessed under rubber dam. 
• Canals will be irrigated with 17% EDTA followed by saline solution.
• A final flush of chlorhexidine will be performed.
• Each root canal will be obturated .
• All the teeth will be restored with IRM as a temporary filling. 

8.3  Duration of study : December 2019 to March 2021.

8.4 Method of data analysis :  One-way ANOVA

                                                   Paired t test

8.5 Does the study require any investigation or intervention to be made on patients, any human or animals?

                  YES

If Yes, briefly describe.

Routine root canal treatment will be performed on patients with the application of ultrasonically activated irrigation system, LAI and laser irradiation by using diode laser.

List of References :

[1] Middha M , Sangwan P , Tewari S , Duhan J . Effect of continuous ultrasonic irrigation on postoperative pain in mandibular molars with nonvital pulps: a randomized clinical trial: International Endodontic Journal; 2017; 50(6):522-530.

[2] Shaktawat AS , Verma KG , Goyal V , Jasuja P, Sukhija SJ , Mathur A. Antimicrobial efficacy of 980 nm diode laser on Enterococcus feacalis in conjunction with various irrigation regimes in infected root canals: An in vitro study; Journal of Indian Society of Pedodontics and Preventive Dentistry; 2018; 36(4):347-351.

[3] Attiguppe PR , Tewani KK , Naik SV , Yavagal CM , Nadig B. Comparative Evaluation of Different Modes of Laser Assisted Endodontics in Primary Teeth: An In vitro Study; Journal of Clinical and Diagnostic Research; 2018; 11(4):ZC124-ZC127.

[4] Hmud R , Kahler WA , Walsh LJ. Temperature changes accompanying near infrared diode laser endodontic treatment of wet canals; Journal of Endodontics; 2010; 36(5):908-11.

[5] Morsy DA , Negm M , Diab A , Ahmed G . Postoperative pain and antibacterial effect of 980nm diode laser versus conventional endodontic treatment in necrotic teeth with chronic periapical lesions: A randomized control trial: F1000Research; 2018; 15;7:1795