Effect of the Simultaneous Working Length Control during Root Canal Preparation on Postoperative Pain

Effect of Laser Therapy on Postoperative Pain and Endodontic Retreatment: A Systematic Review and Meta-Analysis

BACKGROUND

Root canal re-treatment (RCR) cases are considered some of the most challenging cases in the field of endodontics, as they are mostly associated with various iatrogenic errors such as ledge formation, incomplete biomechanical preparation, file separation, and incomplete obturation. These iatrogenic errors lead to defective niches within root canals that may act as reservoirs for various viable microorganisms. Such residual microbial niches may cause postoperative pain even after thorough debridement and reshaping the canals, ultimately leading to a poor prognosis for the tooth. Nowadays, prevention of postoperative pain in re-treatment cases and prognosis are effectively managed by photobiomodulation therapy (PBMT).

METHOD

Relevant studies in the English language published before November 2022 were identified using electronic databases like PubMed, SCOPUS, and EBSCO to conduct bibliographic research. This systematic review is based on 3 studies that were found eligible as per the inclusion and exclusion criteria. This systematic review is in accordance with PRISMA guidelines.

RESULTS

The systematic review indicated a positive impact by significantly decreasing postoperative pain in RCR cases when treated with PBMT. The variation was statistically significant at 24 hours (P = .0002), 48 hours (P = .03), and 72 hours (P = .02). The mean difference at 24 hours was 0.65 (95% CI, 0.32-0.99), at 48 hours was 0.46 (95% CI, 0.05-0.87), and at 72 hours was 0.40 (95% CI, 0.07-0.74). There was no statistical heterogenicity at 24 hours (P > .05), but a medium heterogenicity was observed at 48 hours and 72 hours.

PRACTICAL IMPLICATION

PBMT or low-level laser therapy has shown superior results as compared to the conventional pharmacologic approach in postoperative pain management in RCR cases.

Effectiveness of mineral trioxide aggregate on postoperative pain in non-surgical endodontic treatment: a systematic review of randomized controlled trials

INTRODUCTION

Postoperative endodontic pain can negatively influence the quality of life of the patients. Mineral Trioxide Aggregate (MTA) has gained attention as a potential medicament in various endodontic procedures. MTA has been shown to have desirable properties such as biocompatibility, marginal adaptation, and sealing ability compared to other materials. Limited evidence is available about the effectiveness of MTA on the reduction of postoperative pain following endodontic treatment. This article aimed to compare the non-surgical post-endodontic pain-relieving effect of MTA compared with other materials.

METHODS

Indexed databases (PubMed/Medline, EMBASE, OVID, Scopus, and Cochrane) were independently searched for relevant manuscripts published up to and until June 2023. Randomized controlled trials (RCTs) with a focus on teeth with pulp pathologies, with or without radiolucency, requiring primary endodontic treatment were included. Risk of bias across individual studies was performed using the Cochrane risk of bias tool for interventions.

RESULTS

Out of the initial 169 articles searched, 9 RCTs met the selection criteria. The protocols were like all the studies, but the pain rating scales, filling material, and restoration materials varied. Out of the 9 included studies, in 4 studies MTA significantly reduced postoperative pain levels, 5 studies showed no difference between MTA and other materials, whereas 1 study reported an adverse effect of grey discoloration after MTA.

CONCLUSION

The findings of the present review indicate that MTA may reduce postoperative pain following non-surgical endodontic treatment. However, future standardized studies should be conducted to validate the results.

A Review of the research methods and progress of biocompatibility evaluation of root canal sealers

The function of root canal sealer was to achieve an appropriate three-dimensional filling effect by filling the root canal and some irregular lumen, thereby inhibiting the residual bacteria. There were many types of sealers, but research to find the most suitable ones was still ongoing. In recent years, researchers had continuously improved the performance of sealers by developing new sealers or adding active ingredients to the sealers. However, most sealers exhibit varying degrees of cytotoxicity and tissue responses, which affect clinical therapy efficacy. This review describes different technical approaches, and recent research progress in the biocompatibility evaluation of root canal sealers and provides brief insights into this field by summarising the performance studies of different root canal sealers.

Comparison and Evaluation of Effect of Low Level Laser Therapy (LLLT) with Intracanal Medicament on Periapical Healing

Photobiomodulation (PBM), also commonly referred to as low-level laser therapy (LLLT), uses light energy to elicit biological responses from the cell and normalize cell function. 40 persons with periapical lesions were selected and were assigned randomly into two groups.Group I - Conventional root canal therapy and low-level laser therapy. Group II - Conventional root canal therapy Root canal therapy was completed, and radiographs were obtained and assessed 3, 6, and 9 months postoperative. VAS pain scale was assessed postoperatively on 0, 7th, and 14th days respectively. An independent t-test was used for the evaluation of the data. No significant difference was noted for postoperative pain and PAI scale between both groups Significant difference was noted in the reduction of the periapical lesions for 3 and 9 months follow up, but was not significant for 6 months. The healing was better in Group I which received Low-level laser therapy with the conventional root canal treatment. Low-level laser therapy can be the newer additional treatment modality that can be applied to the periapical lesion for its faster healing.

Endodontic Flare-Ups: An Update

Root canal treatment deals with mechanical and chemical cleaning followed by obturation that promotes healing and repair of periradicular tissues. Flare-ups can occur in between or some days after endodontic therapy leading to unscheduled visit by the patient. This complication is characterized by severe pain and/ or swelling. There is a correlation between number of appointments, intracanal medicament used and flare-ups. However, there is no sure procedure that can avoid this complication. Therefore, this review article has discussed about causes and some procedures to prevent and treat flare-ups.

Post-operative Pain after Different Root Canal Irrigant Activation Methods in Patients with Acute Apical Periodontitis (Randomized Clinical Trial)

Objective To evaluate the degree of postoperative pain in patients with necrotic teeth with symptomatic apical periodontitis after applying ultrasonic irrigation or manual dynamic agitation. Methods Seventy-eight patients diagnosed with necrotic mandibular first molar with symptomatic apical periodontitis were randomly allocated into 1 of 3 separate groups (n=26); Manual Dynamic Agitation group, Ultra X group, or NaviTip group (control). After a single-visit root canal treatment and a specific method of agitation, depending on each group, the patients were given a questionnaire on which they would mark the degree of pain in a scale from 0 to 10 at 6, 12, 24, 48, 72 hours and 7 days post-operative. Data were statistically analyzed with a significance level of P ≤ 0.05. Results Final irrigation protocol including Ultrasonic agitation and NaviTip (control) groups showed significantly lower values of pain than the MDA group. There was a reduction in pain values by time in all groups. Conclusion There was significantly less pain associated with passive ultrasonic agitation and side vented needle (NaviTip) irrigation compared to Manual Dynamic Agitation.

Endodontic postoperative flare-up: An update

Endodontic treatment corresponds to a combined chemical and mechanical approach, followed by a three dimensional hermetic obturation, that eliminate the pulpal and periradiculare disease and boost healing and repair of periradiculare tissue. Despite the advances in the endodontic field, the inter-appointment flare up remains a true nightmare that encounters every dentist. This complication commences a few hours or days after root canal procedures and it is characterized by the development of pain and/or swelling, requiring an unscheduled appointment for emergency treatment. Different studies showed that flare-ups represent a multifactorial phenomenon including mechanical, chemical and microbial factors. In addition, a correlation was found between flare-up and age, gender, tooth type, presence of preoperative pain, tooth condition before treatment, irrigation techniques, number of visits as well as intracanal medication. Moreover, some medicine intake was proved to be efficient in controlling this postoperative pain. However, a clear procedure to avoid its occurrence is yet to be established. In this review, we summarize knowledge about the etiology of flare-up and its related factors. This could be effective in helping dentists to adapt some strategies to prevent it.

Effect of Different Treatment Regimen and Types of Endodontic Sealers on Pain and Periapical Radiographic Changes

INTRODUCTION: The study aims as a pilot study to evaluate the effect of different treatment regimen and different types of endodontic sealers on pain and periapical radiographic changes was studied. MATERIALS AND METHODS: Forty patients in need of an endodontic root canal treatment on anterior teeth were selected and divided into two groups (20 patients each), according to the endodontic treatment protocol (single or multiple visits). Then, each group was subdivided into two subgroups according to sealer used 10 each (AH Plus Jet resin sealer, Total Fill Bioceramic Sealer). To record pain intensity of the patients at different intervals: 1, 2, 3, 7 days, a visual analog scale was used. Furthermore, patients were recalled after 1, 3, 6, 9 months to evaluate periapical radiographic changes. RESULTS: Showed that as regard pain assessment both tested endodontic sealers, as well as single or multiple visits have no statistically significant difference between pain values of patients during all the observation period from immediately post-operative, after 4, 12, 24, 48, 72 h as well as after 7 days (p > 0.05). As regard lamina dura thickness, results showed that with both tested endodontic sealers as well as single or multiple visits, there was no statistically significant difference between lamina dura thickness of patients after 1 month, 3, 6 as well as after 9 months. CONCLUSIONS: Neither number of visits of endodontic treatment nor type of sealer used for obturation affects post-operative pain and thickness of lamina dura.

Predicting postoperative pain following root canal treatment by using artificial neural network evaluation

This study aimed to evaluate the accuracy of back propagation (BP) artificial neural network model for predicting postoperative pain following root canal treatment (RCT). The BP neural network model was developed using MATLAB 7.0 neural network toolbox, and the functional projective relationship was established between the 13 parameters (including the personal, inflammatory reaction, operative procedure factors) and postoperative pain of the patient after RCT. This neural network model was trained and tested based on data from 300 patients who underwent RCT. Among these cases, 210, 45 and 45 were allocated as the training, data validation and test samples, respectively, to assess the accuracy of prediction. In this present study, the accuracy of this BP neural network model was 95.60% for the prediction of postoperative pain following RCT. To conclude, the BP network model could be used to predict postoperative pain following RCT and showed clinical feasibility and application value.

Comparison of the Effects of a Bioceramic and Conventional Resin-Based Sealers on Postoperative Pain after Nonsurgical Root Canal Treatment: A Randomized Controlled Clinical Study

Background: This clinical trial aimed to compare the effects of bioceramic sealer and resin-based sealer on the incidence and intensity of postoperative pain. Methods: Patients with anterior teeth or premolars requiring root canal treatment were assigned to group 1 (n = 51). Those with molars requiring treatment were assigned to group 2 (n = 57). In groups 1En and 2En, root canals were obturated with Endoseal MTA using the single-cone technique. In groups 1AH and 2AH, the sealer used was AH Plus with the continuous wave technique. On the day of canal filling, each patient was instructed to indicate their pain intensity over the 7 day postoperative period, at rest and, while biting, using a visual analog scale. Results: There was no significant difference in the incidence or intensity of postoperative pain between the Endoseal MTA and AH Plus groups during the 7 day postoperative period (p > 0.05). Less time was needed to seal the root canals with Endoseal MTA, especially in group 2 (p < 0.05). Conclusions: Endoseal MTA and AH Plus had similar effects on the incidence and intensity of postoperative pain. The obturation time was shorter when using Endoseal MTA compared to AH Plus.

Association between polymorphisms in catechol-O-methyl transferase, opioid receptor Mu 1 and serotonin receptor genes with postoperative pain following root canal treatment

AIM

To evaluate the effect of single nucleotide polymorphisms in the COMT, OPRM1, 5HT1A, 5HT2A and 5HTR3B genes on the intensity of postoperative pain following root canal treatment.

METHODOLOGY

Ninety-five patients with mandibular and maxillary molar teeth diagnosed with symptomatic apical periodontitis and a level of preoperative pain greater than 50 on a 100 mm visual analogue scale (VAS) were included. Salivary DNA was collected from the participants and stored in Eppendorf tubes at -80 °C. Preoperative percussion pain values were recorded before the root canal treatment procedures. After completion of root canal treatment, the participants were given instructions to record their postoperative pain intensity levels at 24, 48 and 72 h, 5 days and 1 week after treatment, using the VAS. A second visit for the patients after seven days was planned to record their intensity levels of percussion pain on VAS. The percussion test was performed by tapping on the occlusal surface of the tooth with a blunt instrument. A QIAamp DNA Mini Kit was used to isolate DNA from saliva, and SNP Genotyping Analysis software version 1 was used to analyse the genotypes by calculating FAM and HEX signals. The Kruskal-Wallis and Mann-Whitney U-tests were used to evaluate pain intensity values amongst the genotypes, alleles, haplotypes and allele combinations. Nominal data (gender, intake and tooth number) were analysed using a Chi-square test. Bonferroni correction was performed. Thus, the significance level was set at 1.6% (P = 0.016), 2.5% (P = 0.025) and 1.25% (P = 0.0125) for genotype, allele and haplotype comparisons, respectively.

RESULTS

There was no significant difference amongst the genotypes and alleles in terms of pre- and postoperative pain intensity. There was no significant difference amongst the haplotypes formed for the COMT gene in terms of pain intensity. Additionally, there was no significant association between the allelic combination formed for 5HT1A + 5HT2A genes and the intensity of postoperative pain.

CONCLUSION

The findings indicate that none of the evaluated SNPs for COMT, OPRM1, 5HT1A, 5HT2A and 5HTR3B genes were associated with the intensity of postoperative pain.

Comparing the incidence of postoperative pain after root canal filling with warm vertical obturation with resin-based sealer and sealer-based obturation with calcium silicate-based sealer: a prospective clinical trial

OBJECTIVE

This prospective clinical study compares postoperative pain after single-visit, non-surgical root canal treatment of teeth with irreversible pulpitis using two different root canal filling techniques.

MATERIAL AND METHODS

All cases were treated by endodontic residents with a standardized protocol (minimum apical size 35) and filled with one of the two techniques: warm vertical compaction technique (WVT) with gutta percha and epoxy resin-based sealer (AH Plus Jet Root Canal Sealer, Dentsply Maillefer, York, PA, USA) or sealer-based filling technique (SBT) with single cone gutta percha and calcium silicate-based sealer (EndoSequence BC Sealer, Brasseler, Savannah, GA, USA). Surveys were given to participating patients to record pain intensity on a numeric rating scale (NRS, 0-10) at 4, 24, and 48 h postoperatively. Statistical significance was set at 0.05 level.

RESULTS

One hundred ninety-four surveys were distributed over eighteen months. Ninety-two patients returned the survey (41 WVT and 51 SBT), of which 38% were asymptomatic irreversible pulpitis cases. The NRS values reduced over time for both techniques. No statistical difference was found between the two groups at the three time points assessed (p > 0.05). Postoperative pain was related to age, gender, presence of preoperative pain, and sealer extrusion (p < 0.05), however not related to preoperative periapical symptoms (percussion/palpation), dental arch, root type, and experience of the provider (p > 0.05).

CONCLUSIONS

The intensity of postoperative pain for the two obturation techniques was equivalent at evaluated time points.

CLINICAL RELEVANCE

The obturation technique does not influence postoperative pain. After endodontic treatment of symptomatic irreversible pulpitis teeth, the pain subsides in 48 h regardless of the technique.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04462731.

Postoperative Pain After the use of Sodium Hypochlorite gel and Solution Forms: A Randomized Clinical Study

OBJECTIVE

The present study aimed to compare the effect of sodium hypochlorite (NaOCl) gel and solution forms on postoperative pain level.

METHODS

Fifty-two patients were divided into two groups according to the root canal irrigation solution. In the NaOCl solution group, the root canals were irrigated with 2 mL of 5.25% NaOCl between each pecking motion. In the NaOCl gel group, 5.25% NaOCl gel was used according to the manufacturer's instructions. The root canal treatments were completed and the participants were given instructions to record postoperative pain levels on 24, 48, and 72 hours and 1 week after treatment using VAS.

RESULTS

Intergroup analyses revealed that the NaOCl gel group resulted in significantly less postoperative pain than the NaOCl solution group on day 1.

CONCLUSION

It can be concluded that using NaOCl gel during root canal preparation results in less postoperative on day 1 when compared with the NaOCl solution.

Effect of calcium hydroxide alone or in combination with ibuprofen and ciprofloxacin on postoperative pain and periapical prostaglandin E2 level: A randomized clinical study

AIM

The aim of the present study was to compare pure Ca(OH)2, Ca(OH)2 + ibuprofen and Ca(OH)2 + ciprofloxacin in terms of postoperative pain and prostaglandin E2 (PGE2) level in previously treated teeth with periapical lesions.

MATERIALS AND METHODS

Sixty-six patients were randomly assigned into 3 groups according to the intracanal medication (Ca(OH)2, Ca(OH)2 + ibuprofen and Ca(OH)2 + ciprofloxacin). After removing gutta-percha from the root canals, the PGE2 sample collection was obtained by introducing three sterile paper points into the root canals through the root apex (2 mm). Selected intracanal medicament was placed into the root canal and the participants were told to record postoperative pain levels at 24, 48, and 72 h and on 1 week after treatment using visual analog scale (VAS). At the second appointment, the medicaments were removed and second sampling was performed using the same method. The PGE2 levels measured by enzyme-linked immunosorbent assay kits, and the data were statistically analyzed.

RESULTS

All the tested Ca(OH)₂ pastes were found to be significantly effective in lowering the preoperative PGE2 levels. However, intergroup analyses revealed that the Ca(OH)2 + ciprofloxacin group had the highest effectiveness in lowering PGE2 with a significant difference when compared with the pure Ca(OH)2 group. There was no statistically significant difference among the groups in terms of pre- and post-operative pain levels.

CONCLUSION

The Ca(OH)2 + ciprofloxacin medication is more effective than the pure Ca(OH)2 medication in lowering periapical PGE2 level. However, addition of ibuprofen or ciprofloxacin to the Ca(OH)2 paste does not provide extra benefit in terms of post-operative pain relief.

Effect of Bioactive Glass-Based Root Canal Sealer on the Incidence of Postoperative Pain after Root Canal Obturation

The purpose of this study is to evaluate the effect of a bioactive glass-based root canal sealer, Nishika Canal Sealer BG (CS-BG), on the incidence of postoperative pain (PP) after root canal obturation (RCO). Eleven dentists performed pulpectomy or infected root canal treatments for 555 teeth. During RCO, CS-BG was used. After RCO, the rate of PP and the factors affecting PP (pain during RCO and pain immediately after RCO) were analyzed. PP was observed in eight teeth (1.5%), and within 7 days after RCO, there were no teeth with pain. In these teeth with PP, there was a significant difference in the occurrence of pain during RCO, but not in the occurrence of pain immediately after RCO, when compared with pulpectomy and infected root canal treatment. These clinical results show that CS-BG has an excellent biocompatibility, and can suppress the distress of patients during RCO.

Effect of intracanal cryotherapy application on postoperative endodontic pain: a systematic review and metaanalysis

OBJECTIVES

To assess the influence of intracanal cryotherapy application on postoperative pain after endodontic treatment.

MATERIALS AND METHODS

A systematic review (SR) was conducted in seven databases. Articles that were published up to 04 February 2020 were included and randomized clinical trials that used a cold saline solution for final irrigation to manage postoperative endodontic pain were compared with those that used a saline solution at room temperature. Metaanalysis was performed to assess postoperative pain after 6, 24, 48, and 72 h using a random effects model, a confidence interval of 95%, and heterogeneity tested by the I² index. The certainty of evidence was rated using GRADE.

RESULTS

Qualitative and quantitative analysis included eight and six studies, respectively. Individuals treated with cryotherapy presented lower means of postendodontic pain than the controls, 6 and 24 h after endodontic treatment (MD - 1.30 [- 2.32, - 0.28] p = 0.01 and SMD - 0.68 [ - 1.21, - 0.16] p = 0.01, respectively, with very low certainty of evidence). After 48 and 72 h, both groups demonstrated similar means of postendodontic pain (MD - 0.06 [- 0.18, 0.07] p = 0.38 and SMD - 0.54 [- 1.18, - 0.11] p = 0.10, with high and low certainty of evidence, respectively).

CONCLUSIONS

Based on the limited quality evidence, intracanal cryotherapy application reduced postoperative endodontic pain after 6 and 24 h. New clinical trials are needed to support the result of this review.

CLINICAL SIGNIFICANCE

This SR provides information about the use of intracanal cryotherapy in clinical practice, guides clinicians to make evidence-based decisions and suggests recommendations for further high-quality studies.

Postoperative pain after root canal filling with different endodontic sealers: a randomized clinical trial

The aim of this randomized clinical trial was to compare the occurrence and intensity of postoperative pain and analgesic intake after root canal treatment, using different root canal sealers. Sixty single-rooted teeth diagnosed with asymptomatic necrosis and apical periodontitis were randomly assigned to 3 experimental groups (n=20), according to the root canal sealer: AH Plus, Endofill or MTA Fillapex. Endodontic treatment was performed in two sessions, and calcium hydroxide was used as the intracanal dressing. Patients were instructed to record pain intensity as none, slight, moderate and severe. Scores from 1 to 4 were attributed to each level of pain after 24 h, 48 h and 7 days. The need for analgesic intake was also recorded. Differences in the incidence of postoperative pain and the need for an analgesic were analyzed using the chi-square test. Differences in pain intensity after treatment were analyzed using the ordinal (linear) chi-square test. No significant differences were detected among the groups in terms of either incidence or intensity of postoperative pain, or need for analgesic intake, at any timepoint (p>0.05). No pain was reported after 7 days. AH Plus, Endofill and MTA Fillapex used for filling root canals resulted in the same rate of postoperative pain and need for analgesic medication.

Effect of calcium hydroxide mixed with lidocaine hydrochloride on postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis: a preliminary randomized controlled prospective clinical trial

OBJECTIVES

To investigate the effect of calcium hydroxide mixed with lidocaine HCl on postoperative spontaneous pain.

MATERIALS AND METHODS

Sixty patients having irreversible pulpitis and symptomatic apical periodontitis with a preoperative spontaneous pain and percussion pain which was more than 50 on a visual analogue scale (100 mm VAS) were included in this study. After the preparation of the root canals, the patients were randomly distributed into two groups according to the calcium hydroxide vehicle, control group (mixed with saline) and calcium hydroxide mixed with lidocaine HCl (n = 30). Postoperative spontaneous pain scores were recorded by a VAS every day for a week. Data were analysed using one-way analysis of variance, chi-squared test and Mann-Whitney U tests (p = 0.05).

RESULTS

The calcium hydroxide mixed with lidocaine HCl group resulted in significantly less pain compared with the calcium hydroxide mixed with saline group during days 1 to 4 (p < 0.05). There were no significant differences between the groups in terms of postoperative percussion pain levels (p > 0.05).

CONCLUSION

Within the limitations of this study, it can be concluded that the calcium hydroxide mixed with lidocaine HCl can be beneficial in reducing postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis.

CLINICAL RELEVANCE

The calcium hydroxide mixed with lidocaine HCl can be beneficial in reducing postoperative pain in teeth with irreversible pulpitis and symptomatic apical periodontitis.

CLINICAL REGISTRATION NUMBER

TCTR20181121003.

Efficacy of low-level laser therapy in pain management after root canal treatment or retreatment: a systematic review

The aim of this study was to assess the effectiveness of low-level laser therapy (LLLT) for pain management after root canal treatment or retreatment. An electronic search for randomized controlled trials was conducted prior to November 2018, through PubMed, EMBASE, the Cochrane library (CENTRAL), and Web of Science. After filtering, seven articles were included, five related to root canal therapy (RCT) and two related to root canal retreatment (RCR). Six of the included studies presented a moderate risk of bias and a one low risk of bias, based on the Cochrane tool of risk of bias evaluation. The laser treatment included diode laser and indium-gallium-aluminum laser. LLLT was compared with placebo, blank, and ibuprofen treatment. Clinical outcome variables included the prevalence of pain, pain intensity, and need for analgesics after treatment. Three studies showed LLLT could reduce the prevalence of pain significantly after RCT or RCR. Although the effect of LLLT on pain intensity varied at different observation time points and among different studies, most of them found patients had lower pain intensity in the LLLT group. Of the three studies that assessed the need for analgesics after treatment, two studies showed significant benefits. Based on the current evidence, the use of LLLT for pain control in postendodontic therapy may be promising. However, solid conclusions should not be drawn definitely, given that more high-quality randomized controlled trials are required to further evaluate the efficacy of LLLT for pain management after RCT and RCR.

Effect of intracanal cryotherapy on the fracture resistance of endodontically treated teeth

OBJECTIVE

The aim of this study is to evaluate the effect of intracanal cryotherapy on the fracture resistance of endodontically treated teeth.

MATERIALS AND METHODS

Sixty single-rooted maxillary lateral incisor teeth with single root canals were selected and randomly divided into two groups (n = 30). The specimens were immersed in distilled water, which was heated to 37 °C during the procedures. The root canals were chemomechanically prepared up to the apical size of 50 and assigned to either the control group or the cryotherapy group. The specimens in the cryotherapy group were irrigated with 20 mL sterile cold (2.5 °C) saline solution, which was delivered with an EndoVac system for 5 min, whereas the specimens in the control group received a sterile saline solution at room temperature. The fracture resistance of the specimens was then tested with a universal testing machine. The data was analyzed using the independent sample t test with a 5% significance threshold.

RESULTS

The fracture strength of the specimens in the intracanal cryotherapy group was significantly lower than that of the control group (p< .05).

CONCLUSIONS

Application of intracanal cryotherapy as a final irrigant reduced the vertical fracture resistance of prepared roots when compared to the control group.