Project Summary:

            Standard root canal preparation with mechanical instrumentation alone is not able to completely eradicate biofilms, smear layer and/or microrganisms lodged in complex areas such as lateral canals, accessory canals, isthumi and ramifications present within the root. So, chemical irrigation is deemed necessary for complete disinfection of root canals. Chlorhexidine (CHX) has been used as final irrigant as it exerts a prolonged antimicrobial effect (substantivity), which may prevent bacterial recolonization with no effect on organic or inorganic tissues. Sodium Hypochlorite has also been used but it dissolves only organic tissue with no effect on inorganic tissue. EDTA (Ethylene diamine tetracetic acid), a chelating agent  removes inorganic component of smear layer and is usually used after irrigation with sodium hypochlorite for complete smear layer removal.  Thus to simplify irrigation protocols and to achieve disinfection and smear layer removal simultaneously (one single step), new combinational products have been introduced as the final irrigants after NaOCl: MTAD and QMix (both Dentsply Tulsa Dental Specialties, Tulsa, OK). So aim of the study is to compare periapical healing outcome after the use of newer irrigant (QMix) with CHX and EDTA as final irrigants after single visit root canal treatment in necrotic multirooted teeth with periapical lesions.

Although several studies in the literature have used QMix irrigation solution, there have been very few in vivo studies, with most of the studies being laboratory studies.

 108 asymptomatic patients with necrotic, mature permanent mandibular molar teeth with periapical lesion will be recruited over the period of 6 months. Root canal procedure with standardized protocols will be performed after taking the informed consent from patients. The patients will be divided into 3 groups, where 5ml of QMix, Chlorhexidine or EDTA will be used as a final irrigant, using a randomized block design. Teeth will then be obturated and restored with composite restoration. Patients will be followed up for clinical and radiographic (PAI score) healing evaluation at every 3months till 12months. Data analysis will be done after 12month followup.         

(a) Rationale of the study supported by cited literature: To evaluate healing of 

                                 periapical lesions following use of final irrigants   

            (b) Hypothesis: To compare the difference in healing after use of different final   

                                               irrigant solutions

            (c) Research questions.:  a) Is there any difference in healing after use of final  

                      irrigants (QMix, Chlorhexidine, EDTA) in single visit root canal treatment?

                     b) Difference in Post operative pain after use final irrigant

Methodology:

              The current study will include patients reporting to the outpatient department of dentistry at AIIMS Rajkot.

Inclusion criteria:

1.     Systemically healthy individuals with age range between 18�’69 years will be included

2.     Necrotic, mature permanent mandibular molar teeth with periapical lesion having periapical index (PAI) score of >2 and <5 will be included.  

3.     Asymptomatic nonvital teeth with a negative response to electrical and cold tests and a negative response to percussion and palpation tests will be included.

4.     Teeth without fractures, cracks, or apical resorption will be included.

Exclusion criteria:

1.     Patients with history of drugs antibiotics usage within the previous week.

2.     Patients with a history of susceptibility or adverse reactions to any drugs or materials that will be used in the study.

3.     Presence of calcified root canals or severe periodontal problems in the tooth in question

4.     Teeth with open apex

5.     Pregnant or breastfeeding women.

Sample Size:

·       According to previous study, 12 months after the canal treatment there was a 2.08 ± 0.30 decrease in the PAI score of the NaOCl group.

•       With current use of QMix irrigation solution, we expect decrease in the PAI score of at least 10% at the end of 12 months. We calculated a minimum sample size of 30 patients per group due to a possible decrease of >0.20 units (10% of 2.08) in the Qmix group, which would be significant with 80% power and 5% error level.

•       To compensate for the expected attrition in the patient pool over the period of time, a decision was made to enroll at least 36 subjects in each group.

Root canal procedure:

After obtaining the informed consent, intraoral periapical radiograph will be obtained using digital imaging system RVG (Woodpecker software). The patients will be divided into 3 groups, where QMix, Chlorhexidine and EDTA will be used as a final irrigant, using a randomised block design of 30  patients per block. EDTA group will be used as control group These randomisation blocks will be prepared on computer by a biostatistician. During treatment, the dental practitioner will use the irrigation solution according to the order defined in the randomisation block. For blinding purposes, sealed numbered syringes containing the final irrigation solutions will be covered with identical tape, prepared, and packaged by a dental nurse not involved in the study so that the syringe contents were not visible and could not be distinguished A dental assistant will give solution to the dentist according to the patient’s group number.

The concerned tooth will be anaesthetised with 2 millilitres (ml) of lignocaine hydrochloride containing 1:200000 adrenaline and isolated under dental dam. The endodontic access cavity will be opened with a sterile diamond round bur. After locating the canals,  #10 K-file (MANI,Japan)  will be used to scout the the canal. The working length will be determined using an electronic apex locator (RootZx Mini; J Morita, Japan) and will be confirmed radiographically. Biomechanical preparation will be done by Protaper Gold (Sx-F3) rotary instruments alongwith copious irrigation of 5.25% sodium hypochlorite to remove the dead necrotic debris. Final irrigation will be done with 5ml of either Qmix, Chlorhexidine or EDTA solution as per blinding protocol and will be activated using manual or sonic activation. The root canals will be dried using sterile paper points and will be obturated with a single cone technique using gutta-percha (Dentsply, Sirona) suitable for master apical file and a root canal paste (AH Plus, Dentsply, Sirona) with epoxy resin content. After obturation, root canal filling will be checked by radiography. Permanent restorations of the teeth were made with composite material (3M Espe, Turkey),

Followup:

Patient will be recalled every 3 months for evaluation of periapical healing till 12 months. Both clinical and radiographic evaluation will be done.