Comparison of the Postoperative Pain Following Endodontic Irrigation Using 1.3% Versus 5.25% Sodium Hypochlorite in Mandibular Molars with Necrotic Pulps

Endodontic irrigation


I N T R O D U C T I O N A R T I C L E I N F O A B S T R A C T
experienced after root canal treatment, can stem from various factors throughout the treatment process.These factors encompass pre-treatment considerations, such as the initial condition of the tooth and surrounding tissues, as well as intra-treatment variables, including the number of visits required for treatment completion and the speci c techniques employed during the procedure [11,12].Additionally, post-treatment factors, such as the type of irrigant and intracanal medication utilized, along with the method of root canal instrumentation and lling, can also in uence the likelihood and severity of post-endodontic pain [13].One of the commonly used agents in endodontic procedures is sodium hypochlorite (NaOCl), renowned for its e cacy in dissolving organic matter and its potent antimicrobial properties.Despite its widespread use over seven decades, it is crucial to note that NaOCl, particularly at higher concentrations, has the potential to irritate the surrounding tissues, leading to periradicular tissue irritation [14].Complications arising from the extrusion of sodium hypochlorite during endodontic procedures have been linked to increased pain levels, especially in cases involving necrotic teeth.Therefore, while NaOCl remains a valuable tool in endodontic practice, careful attention to its concentration and proper application techniques is imperative to mitigate the risk of associated pain and complications [15].The investigation contrasts postoperative discomfort after 24 hours following endodontic rinsing utilizing 1.3% versus 5.25% sodium hypochlorite in mandibular molars with necrotic pulps, aiming to address a local gap in information.Root canalassociated pain is a major concern for patients and dentists, with no agreed-upon pain control method.This study aims to identify the most effective treatment for postoperative endodontic pain by comparing both groups simultaneously.The study was aimed to compare the postendodontic pain scores between 1.3% and 5.25% NaOCl irrigants in necrotic lower permanent molars.

M E T H O D S
mandibular molars with nonvital pulps, individuals of either gender, mature teeth with a closed apex, and ages ranging from 18 to 60 years.Conversely, exclusion criteria comprised non-consenting individuals, patients with a history of allergy to any medications, retreatment cases, and patients who were taking medications for pain.Additionally, individuals with a history of respiratory, cardiovascular, or neurological disorders, as well as primary teeth, were excluded from the study.The study was carried out after obtaining ethical approval from the hospital concerned.Patients undergoing root canal treatment at the dental Department, LUMHS, who met the inclusion criteria, were recruited.During patient's initial c appointment, the study's aim, along with its potential risks and bene ts, was thoroughly explained, and informed consent was obtained.Additionally, a brief demographic history was collected from each patient.Subsequently, patients were randomly assigned to either group A (undergoing endodontic irrigation with 1.3% sodium hypochlorite) or group B (undergoing endodontic irrigation with 5.25% sodium hypochlorite) using sealed opaque envelopes.Root canal treatments were performed across two sessions.During the initial session, each tooth received anesthesia using 1.8 ml of 2% lignocaine hydrochloride (Medicaine inj 1:100,000, Huons Co., LTD) administered via the inferior alveolar nerve block technique.Following access preparation, rubber dam isolation was applied to each tooth.Subsequently, the pulp chamber was lled with 3 mL of irrigant.Canal patency was then established, and an initial glide path was created using #10 and #15 K-les (Mani K-les).After canal preparation, the working length was established utilizing an apex locator (Woodpecker Woodpex III) and con rmed radiographically to be 0.5mm occlusally to radiographic apex.The root canal was prepared using a NiTi rotary system (M3-Pro Gold) and a torque-controlled endodontic motor (Tangshan Umg M e d i c a l I n s t r u m e n t C o ., L t d ) , a d h e r i n g t o t h e manufacturer's guidelines.Canal shaping commenced with the Sx instrument, shaping the coronal two-thirds initially, followed by shaping the apical third with instruments S1, S2, F1, F2, or F3.Before each instrument change, apical patency was ensured with a size 10 K-le.Syringe irrigation with 3 mL of irrigant occurred between instruments, maintaining needle penetration 3mm shorter than the canal's working length.Once preparation reached the master apical instrument, adjusted by a rubber stopper, a nal ush with 5 mL of saline was executed.Paper points were utilized to dry the canals, and a dry cotton pellet was placed in the pulp chamber, restored with temporary restorative material (Cavit).During the second visit, following the removal of temporary lling and placement of a rubber dam, the root canals underwent irrigation with the same solution used during the initial visit.Subsequently,

Endodontic Irrigation Group
Table 2 shows the comparison of pre-and post-operative pain scores between the two endodontic irrigation groups comprising a total of 60 participants.For pre-operative pain scores, the mean Visual Analog Scale (VAS) score for the 1.3% NaOCl group was 3.16 ± 0.64, while for the 5.25% NaOCl group, it was 3.40 ± 0.49.The difference in pre-operative pain scores was not statistically signi cant (p=0.123) between the two groups.However, for postoperative pain scores, the mean VAS score for the 1.3% NaOCl group was 1.33 ± 0.47, signi cantly lower than the 1.63 ± 0.66 observed in the 5.25% NaOCl group (p=0.036).Table 3 shows the comparison of Post-Operative Pain (VAS) scores between types of irrigation, strati ed by age group.For participants aged 18-35 years, the mean post-operative pain score was signi cantly lower in the 1.3% NaOCl group (1.15 ± 0.37) compared to the 5.25% NaOCl group (2.00 ± 0.65), with a p-value less than 0.001.However, for participants aged 36-60 years, while the mean postoperative pain score was lower in the 1.3% NaOCl group (1.63 ± 0.50) compared to the 5.25% NaOCl group (1.26 ± 0.45), this difference was not statistically signi cant (p=0.091).4 presents the comparison of Post-Operative Pain (VAS) scores between types of irrigation, strati ed by gender.For male participants, the mean post-operative pain score was signi cantly lower in the 1.3% NaOCl group (1.00 ± 0.01) compared to the 5.25% NaOCl group (1.75 ± 0.45), with a p-value less than 0.001.However, for female participants, while the mean post-operative pain score was slightly higher in the 1.3% NaOCl group (1.43 ± 0.50) compared to the 5.25% NaOCl group (1.55 ± 0.78), this difference was not statistically signi cant (p=0.62).Based on our ndings, it can be concluded that endodontic irrigation with 1.3% NaOCl was more effective in reducing post-operative pain compared to irrigation with 5.25% NaOCl.

C O N C L U S I O N S
All authors have read and agreed to the published version of the manuscript.

A u t h o r s C o n t r i b u t i o n
Conceptualization: MM Methodology: MM, ER, SP Formal analysis: MM Writing, review and editing: PM, AMNQ, AGS

D I S C U S S I O N
The observation of frequent postoperative pain after root canal treatment can be attributed to a combination of mechanical manipulation, chemical irritation, and residual infection, particularly in teeth with nonvital pulps.Addressing these factors through careful technique, appropriate medication, and thorough disinfection can help minimize postoperative discomfort and improve patient outcomes following root canal treatment [16].It is deemed essential by clinicians to focus on effective pain management during both endodontic procedures and the post-operative period.Our study's average age in group A was 33.76 ± 4.06 years and in group B was 32.10 ± 5.84 years with a statistically insigni cant difference (p = 0.352).Regarding gender distribution, in group A, 23.3% were males and 76.7% were females, whereas in group B, 40.0% were males and 60.0% were females.Nonetheless, these gender differences were also statistically non-signi cant (p = 0.165).The observations made in this study parallel those reported by Mostafa et al., in their research, out of 308 patients, 178 were females and 130 were males, spanning an age range of 25 to 45 years, with an average age of 31.88 ± 5.821 years [17].This study sought to evaluate and compare the levels of post-endodontic pain using two different concentrations of NaOCl, speci cally 1.3% and 5.25%, in necrotic lower molars.Results showed a signi cantly lower average Post-Endodontic Pain (VAS) score of 1.33 ± 0.47 in the 1.3% NaOCl group compared to 1.63 ± 0.66 in the 5.25% NaOCl group, with a p-value of 0.036.These ndings suggest that using 1.3% NaOCl for irrigation during root canal treatment may offer superior post-operative pain management compared to using 5.25% NaOCl.A study by Mostafa et al., was conducted in Egypt, involving 308 patients, each presenting with both asymptomatic and symptomatic molars [17].They were randomly assigned into two equal groups, utilizing the permuted-block method, based on NaOCl concentration: 1.3% or 5.25% (n = 154).The study ndings suggested that the utilization of 1.3% NaOCl resulted in diminished intensity and frequency of post-endodontic pain when compared to 5.25% NaOCl in mandibular molars with nonvital pulps treated through a two-visit root canal approach.The study by Farzaneh S et al., in Iran, involving 122 patients with irreversible pulpitis in mandibular molars, compared the effects of 2.5% and 5.25% NaOCl during root canal treatment [18].Results showed signi cantly lower post-endodontic pain in patients treated with 5.25% NaOCl during the rst 72 hours (P = 0.021).Additionally, these patients required fewer analgesics (P = 0.001).This suggests that using 5.25% NaOCl may reduce early postendodontic pain in one-visit root canal treatment for mandibular molars with irreversible pulpitis.In this study, there was a signi cant difference in the average Post-Endodontic Pain (VAS) scores between the 18-35 years age group (p < 0.001) for the two irrigation groups, whereas no signi cant difference was observed in the 36-60 years age group (p = 0.091).However, it's worth noting that several previous studies have reported no association between age and postoperative pain [18,19].Our results showed that in males, 5.25% NaOCl was more effective than 1.3%, indicating sexual dimorphism for our outcome variable.Notably, within each group, females consistently reported higher mean post-endodontic pain levels than males.These ndings echo previous research, which has presented con icting evidence regarding the impact of gender on postoperative pain.Some studies, such as that conducted by Mostafa et al., suggest that females are more prone to experiencing heightened pain levels [17].However, contrary to this, Middha et al., found no correlation between gender and post-endodontic pain following endodontic treatment.Acknowledging the limitations inherent in our study, such as its small sample size and single-c enter design, it is important to note that our study exclusively enrolled patients with non-vital pulps [20].Expanding the scope to include a more diverse patient population could enhance the generalizability of our ndings.Thus, we recommend future large-scale studies to thoroughly investigate the effects of various irritant concentrations on both short-and long-term outcomes.

Table 1 :
Distribution of Gender and Age in Both Groups the canals were re-prepared using identical instrument sizes as in the rst visit.For canal lling, a modi ed single cone technique was employed, utilizing Gutta purcha cones matched in size (ProTaper Universal E-Dental Mart) and a non-eugenol calcium hydroxide polymeric root canal sealer (Sealapex Kerr Endodontics).This was followed by temporary cavity lling.Patients were then assessed for postoperative pain at 24 hours.Preoperative pain was assessed using a Visual Analog Scale (VAS) ranging from 0 (no pain) to 10 (unbearable pain).The collected data, encompassing both quantitative and qualitative variables, were recorded in the Performa.SPSS version 20.0 was utilized for the statistical analysis.Mean and standard deviation (SD) were computed for quantitative variables such as age and VAS pain scores in both groups.For qualitative variables like gender and severity of pain, frequency and percentage calculations were performed.Normality was con rmed using the Shapiro-Wilk test, thus allowing for the application of parametric tests.The independent t-test was employed to compare the score of postoperative pain between both groups.Effect modi ers were managed through strati cation of age, gender, and duration of root canal treatment to assess their impact on the outcome variables.Post-strati cation Chi-square test and independent t-test were conducted, with a signi cance level set at p ≤ 0.05.

Table 2 :
Comparison of Pre and Post-Operative Pain Score between Irrigation Groups (n=60) *Independent test

Table 3 :
Comparison of Post-Operative Pain (VAS) Score between Types of Irrigation Strati ed by Age Group *Independent t testTable

Table 4 :
Comparison of Post-Operative Pain (VAS) Score between Types of Irrigation Strati ed by Genders *Independent t test