Postoperative pain after manual and mechanical glide path: a randomized clinical trial

The short-term postoperative pain and impact upon quality of life of pulpotomy and root canal treatment, in teeth with symptoms of irreversible pulpitis: A randomized controlled clinical trial

BACKGROUND

Few studies focus upon patient-reported outcomes in endodontics.

AIM

To determine whether full pulpotomy offers a less painful, improved health-related quality of life (HRQoL) compared with root canal treatment (RCT) in cases of irreversible pulpitis (IP) in the 7 days after the treatment.

METHODOLOGY

One hundred sixty-eight participants presenting with symptoms of IP were randomized to either pulpotomy (n = 86) or RCT (n = 82). Two participants were excluded, 61 participants underwent full pulpotomy with Biodentine (35.7%), 80 had RCT (46.8%), and 25 were randomized to have pulpotomy which progressed to RCT (PRCT) due to uncontrollable bleeding (14.6%). Clinical and radiographic assessments, using CBCT and periapical radiographs, were carried out preoperatively, for the evaluation of the results only CBCT images were used. Pain (VAS) and HRQoL (EQ 5D) assessments were carried out at baseline and Days 1, 3, 5 and 7 post-baseline. Analysis included descriptive and continuous variables, chi-squared, Fisher's exact, and two-sample t-tests.

RESULTS

In pulpotomy and RCT groups, VAS pain decreased significantly over the first week (p < .001). The magnitude of reduction was similar in RCT and pulpotomy (p = .804), RCT and PRCT (p = .179), pulpotomy vs. PRCT (p = .144) and in the comparison of combined RCT /PRCT groups (ORCT) with Pulpotomy (0.729). However, the overall level of VAS pain was significantly higher in the PRCT group than in the Pulpotomy (p = .045) and RCT group (p = .049). Using CBCT, significantly more radiolucencies were found in the PRCT group than in the pulpotomy group and overall teeth presenting with CBCT radiolucencies had significantly higher pain scores (p = .015), particularly at Days 1, 3 and 5. There were significant differences in many OHRQoL domains (Questions 1, 6, 11 and 12) between RCT and PRCT groups with higher frequencies of the impact of oral health problems at Day 0 and Day 7 in the PRCT group.

CONCLUSION

In the treatment of IP, pulpotomy is as effective as RCT in reducing post-operative pain, and improving QoL and HRQoL, teeth displaying uncontrollable bleeding and periapical radiolucencies detected using CBCT are associated with more intense postoperative pain and lower QoL.

Glide Path in Endodontics: A Literature Review of Current Knowledge

The introduction of nickel-titanium rotary instruments revolutionized shaping procedures as they were able to produce a well-tapered preparation while reducing operator fatigue. The major drawback of rotary instruments was the high risk of fracture due to bending and torsional stress. Thus, the creation of a glide path has been advocated and recommended by most rotary instrument manufacturers. The aim of the present review is to summarize existing knowledge on glide path preparation and identify areas where further research is needed. The primary goal is to provide a comprehensive overview of the techniques and instruments used in glide path preparation, highlighting their advantages and limitations. The secondary goal is to explore the effect of glide path creation on the overall success of endodontic treatment, particularly in terms of reducing procedural errors and improving treatment outcomes. An online search on PubMed, ScienceDirect, UCLA, and Scopus databases was conducted, and 116 articles were identified. Eligible articles were divided into nine categories based on what they researched and compared. The categories included centering ability and/or root canal transportation, cyclic fatigue resistance, glide path and shaping time, tortional stress resistance, apical extrusion of debris and/or bacteria, defects in dentine walls, file separation, postoperative pain assessment, and scouting ability and performance. Establishing a glide path reduces root canal transportation, especially with rotary methods. Reciprocating and heat-treated files offer higher fatigue resistance and shorter preparation time. Instruments with shorter pitch lengths have greater torsional strength. Preparation and coronal preflaring reduce apical debris and bacteria. Glide paths do not affect dentine microcracks, file separation, or defects but reduce immediate postoperative pain and improve cutting ability. Randomized trials are needed to assess their impact on treatment outcomes.

The effect of apical patency on postoperative pain following endodontic therapy: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to determine whether apical patency increases postoperative pain after endodontic therapy. This study explored the degree and incidence of postoperative pain during root canal therapy, as well as the number of required analgesic doses. We searched PubMed, Scopus, Embase, Web of Science, Cochrane Library, and gray literature from the date of database inception until May 2023. RevMan 5.4 software was used for data analysis. Twelve studies were considered eligible for meta-analysis. The mean pain scores on days 1 (mean difference [MD] = -1.69) and 2 (MD = -0.85) differed significantly between the apical patency and non-patency groups. The odds for pain after 24 h were significantly lower (OR 0.59) in the apical patency group than in the non-patency group. Furthermore, the mean number of required analgesic doses was not significantly different between the two groups. In conclusion, apical patency significantly alleviated postoperative pain (low-quality evidence) and reduced the incidence of pain (moderate evidence). However, high-quality randomized controlled trials are required to validate these findings.

Postoperative pain after single-visit root canal treatments in necrotic teeth comparing instruments' kinematics and apical instrumentation limits - a prospective randomized multicenter clinical trial

OBJECTIVES

This prospective randomized multicenter clinical trial (PRMCT) investigated postoperative pain after single-visit root canal treatments in teeth affected by pulp necrosis (PN), and asymptomatic apical periodontitis (AAP) (with apical radiolucent areas) or normal periradicular tissues (without apical radiolucent areas) comparing different instruments' kinematics and apical instrumentation limits.

METHODS

Before chemomechanical preparation, 240 patients/teeth were randomly distributed into four groups (n = 60) according to the instruments' kinematics (rotary or reciprocating) and apical instrumentation limits (with or without intentional foraminal enlargement [IFE]). After that, specimens were submitted to the same irrigation and obturation techniques, and the patients were referred to undergo the definitive restorations. No medication was prescribed, but the patients were instructed to take either paracetamol (750 mg every 6 h for three days) or ibuprofen (600 mg every 6 h for three days) in pain cases. Postoperative pain incidence and levels were assessed at 24-, 48-, and 72 h following treatment completion according to a verbal rating scale (VRS) following a score. The Kolmogorov-Smirnov test was applied to assess the normality of the data. Mann-Whitney U, Chi-square, Friedman's ANOVA, and Friedman's multiple 2 to 2 comparison tests were employed to identify potential significant statistical differences among the variables in the study groups (P < .05).

RESULTS

Significant statistical differences were only observed among the groups considering tooth, periradicular status, and the occurrence of overfilling (sealer extrusion) (P < 0.00). Patients with teeth instrumented through rotary kinematics and without IFE experienced lower rates of postoperative pain; however, this difference was relevant only at 24 h (P < 0.05).

CONCLUSIONS

Postoperative pain was lower after using a rotary file system (Profile 04) inserted up to the apical constriction (AC). However, this finding was just statistically meaningful at 24 h.

TRIAL REGISTRATION

This PRMCT was approved by the Human Research Ethics Committee of the Paranaense University - UNIPAR, Francisco Beltrão, PR, Brazil (CAAE. 46,774,621.6.0000.0109) on 02/09/2021. It was registered at The Brazilian Registry of Clinical Trials - ReBEC (RBR-3r967t) on 01/06/2023, was performed according to the Principles of the Helsinki Declaration and is reported following the Consolidated Standards of Reporting Trials Statement.

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.

Evaluation of Pain Following the Use of Different Single-file Glide Path Systems: A Randomized Clinical Trial

INTRODUCTION

This study aimed to evaluate postoperative pain intensity following glide-path preparation using the ProGlider (PG) and WaveOne Gold Glider (WOGG) systems in asymptomatic teeth with necrotic pulp and periapical lesions.

METHODS

In this randomized clinical trial (ClinicalTrials.gov ID: NCT05955742) maxillary and mandibular molars with asymptomatic apical periodontitis of 78 patients (age, 18-65 years) were included. The patients were randomly divided into 3 groups: control (n = 26), PG (n = 26), and WOGG (n = 26). All the systems were used according to the manufacturer's instructions, and all the root canal treatments were completed by a single operator within 2 sessions. Postoperative pain was assessed using a numerical rating scale at 6, 12, 18, 24, 48, and 72 hours. Analgesics administered and abscess formation were also recorded. Statistical analyses were performed using the Mann-Whitney U, Bonferroni Dunn, Friedman, Chi-square, and Fisher exact tests.

RESULTS

The postoperative pain at 12 and 18 hours was lower in the WOGG group than in the other groups (P < .05). The postoperative pain scores at 6 and 24 hours were higher among women than among men (P < .05). The highest postoperative pain scores were observed at 6 hours (P < .05).

CONCLUSIONS

The WOGG glide-path file system was associated with less postoperative pain than the other systems. Abscess formation and analgesic use were higher in the PG group than in the other groups. Postoperative pain was greater in women than in men.

Association between single-nucleotide polymorphisms in serotonin receptor 2A and melatonin receptor 1A genes and pain after root canal treatment

AIM

This study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in the genes encoding 5-HTR2A (5-Hydroxytryptamine (serotonin) receptor 2A) and MTNR1A (melatonin receptor 1A) may contribute to postoperative pain perception after root canal treatment. We hypothesised that SNPs in HTR2A and MTNR1A genes were associated with postoperative pain after root canal treatment.

METHODOLOGY

This genetic cohort study enrolled patients with single-rooted teeth diagnosed with pulp necrosis and asymptomatic apical periodontitis before root canal treatment. Root canal treatment was performed in one session using a standardized protocol. Postoperative pain and tenderness were assessed using a visual analogue scale (recorded every day for 7 days and on the 14th and 30th days after root canal treatment). Genomic DNA was extracted from saliva and used to genotype the SNPs in HTR2A (rs4941573 and rs6313) and MTNR1A (rs6553010, rs6847693 and rs13140012) using real-time polymerase chain reaction. Genotypes were compared using univariate and multivariate Poisson regression with generalized estimating equations (p < .05).

RESULTS

In total, 108 patients were enrolled in this study. The SNPs rs6553010 (MTNR1A), rs4941573 and rs6313 (HTR2A) were associated with an increased risk of developing pain after root canal treatment (p < .05).

CONCLUSIONS

This study suggests that SNPs in HTR2A and MTNR1A influence pain response after root canal treatment.

Postoperative pain perception and associated risk factors in children after continuous rotation versus reciprocating kinematics: A randomised prospective clinical trial

To compare the postoperative pain of continuous rotation and reciprocating movements after pulpectomy of non-vital primary molars and determine associated risk factors. 146 children aged 4-8 years with one primary molar indicated for pulpectomy were randomly assigned to two equal groups: those instrumented with continuous rotation motion (Hyflex EDM Coltene/Whaledent) and reciprocating motion (Reciproc R25 (VDW)). A 4-point pain scale was used to assess postoperative pain frequencies, which were compared at different intervals using the Chi-square test. Postoperative pain risk factors were determined using logistic regression analysis. There was no statistically significant difference between the follow-ups. Gender, pulp status, and radiographic radiolucency increased the risk of postoperative pain incidence. Postoperative pain likelihood in children with chronic apical periodontitis was 8.72 times that of children with necrotic pulps. Postoperative pain after instrumentation with both kinematics was comparable. Postoperative pain incidence is increased by preoperative pulp condition, radiographic radiolucency, and gender.

Evaluation of the Impact of Different Instrumentation Techniques on the Incidence of Postoperative Pain in Patients Undergoing Root Canal Treatment

BACKGROUND

Postoperative pain is a common concern in root canal treatment, and the choice of instrumentation technique can significantly impact patient comfort. This study aimed to evaluate the impact of different instrumentation techniques on the incidence of postoperative pain in patients undergoing root canal treatment.

METHODS

A randomized controlled trial was conducted on 208 patients randomly assigned to four groups: step-back preparation, crown-down preparation, hybrid technique, and conventional instrumentation. Pain intensity was assessed using a verbal rating scale (VRS) at six, 12, 24, 48, and 72 hours postoperatively. Data were analyzed using appropriate statistical methods.

RESULTS

The mean pain scores and standard deviations (SDs) were calculated for each instrumentation technique at different time intervals. At six hours, the step-back preparation group reported a mean pain score of 2.3 (SD = 0.8), the crown-down preparation group had a score of 2.8 (SD = 0.9), the hybrid technique group had a score of 2.5 (SD = 0.7), and the conventional instrumentation group had a score of 3.1 (SD = 0.1). The differences in pain scores between the groups were statistically significant at all time intervals (p < 0.05).

CONCLUSION

The choice of instrumentation technique significantly influenced the incidence of postoperative pain in root canal treatment. The step-back preparation technique was associated with lower pain intensity than the crown-down preparation, hybrid technique, and conventional instrumentation. These findings highlight the importance of considering the instrumentation technique to optimize patient comfort during and after root canal treatment.

Incidence and Intensity of Pain Following Endodontic Treatment by Different Instrumentation Techniques in Teeth With Periapical Lesion

AIM AND OBJECTIVES

 This study was carried out to compare the effectiveness of hand and rotary instrumentation techniques on postoperative pain in asymptomatic necrotic premolars with periapical lesions and instrumented by a modified step-back technique using a K file, crown down by continuous rotary motion technique using ProTaper Universal (Dentsply Mailefer, Ballaigues, Switzerland), and with the reciprocation technique using WaveOne (Dentsply Sirona, Charlotte, NC, USA).

MATERIALS AND METHODS

 For this study, 66 premolars with single roots and canals were chosen. The procedure was completed in a single visit. Following access opening, the working length was initially determined using an apex locator and then confirmed after inserting K file #10 by radiograph. The canal was cleaned and shaped using a grouping system. After the master apical preparation, the canal was dried by paper point and obturated with gutta-percha and AH plus sealer, an epoxide-amine resin pulp canal sealer. In order to confirm the obturation, a radiograph was taken. After that, a permanent restoration material was used to seal the access cavity. Following that, patients to whom the visual analog scale (VAS) had already been explained were contacted by phone at six, 12, 24, and 48 hours.

RESULTS

 In this study, compared to a stainless steel instrumentation technique, WaveOne instrumentation caused more noticeable pain. The results of the current study showed that, on average, postoperative pain scores decreased over the course of the 12 to 48-hour period, reaching a minimum or a maximum at 48 hours (p<0.01).

CONCLUSION

 Postoperative pain was produced by all instrumentation methods used in the study. In comparison to ProTaper and WaveOne, instrumentation using the modified step-back technique with K files caused less pain, especially over the course of a 24-hour period.

Pain Relief Effects and Safety of Transitional Therapy in the Treatment of Posterior Teeth of Pregnant Women with Symptomatic Irreversible Pulpitis and Symptomatic Apical Periodontitis

Purpose

To assess the pain relief effects and safety of transitional therapy (TT) in the treatment of posterior teeth of pregnant women with symptomatic irreversible pulpitis and symptomatic apical periodontitis.

Methods

A prospective cohort clinical study was conducted in the Department of Stomatology at Shenzhen Maternity & Child Healthcare Hospital, China, from January 2017 to December 2019. We enrolled 62 pregnant women with acute dental pain caused by posterior teeth with symptomatic irreversible pulpitis or symptomatic apical periodontitis. Among the 62 participants, 34 received TT, and 28 chose nontreatment during pregnancy. We evaluated the pain relief with the verbal numerical rating scale (VNRS) scores of pain perception in the clinical study, as well as the anti-bacterial medicament filling conditions of canals of in vitro models. Moreover, we investigated the safety outcomes, such as gestational age, neonatal head circumstance, birth weight, and body length.

Results

The VNRS scores of the participants treated with TT were significantly lower than those of the nontreatment group 2 days after treatment (P<0.001). TT treated pregnant women experienced significantly more pain decreases in VNRS scores than their counterparts(P<0.05). The optimal anti-bacterial medicament filling conditions of canals of in vitro models by TT method were comparable with those of canals instrumented with traditional RCT method. Moreover, no significant differences of safety outcomes were observed between pregnant women of these two groups.

Conclusion

The transitional therapy is efficient in alleviating acute dental pain of posterior teeth of pregnant women with symptomatic irreversible pulpitis and symptomatic apical periodontitis, and maintaining painless chains throughout pregnancy with no adverse effects on neonatal birth outcomes.

Patient discomfort levels during instrumentation procedure using nickel-titanium files with different kinetic movements

This study evaluated the perceived vibration, noise and discomfort levels associated with two nickel-titanium file systems with different kinetics; reciprocating motion (REC) using WaveOne Gold and continuous rotation motion (CON) using ProTaper NEXT. Forty roots with two canals from maxillary premolar and molar of 40 patients were included. Root canals were instrumented using each system for each canal. Patients were surveyed about the vibration, noise and discomfort experienced using visual analogue scale, and their preference. The responses were statistically analysed using Wilcoxon Signed-Rank test, Mann-Whitney U test and Spearman's rank correlation test at the 95% of significance level. The vibration, noise and discomfort experienced were significantly greater in REC than CON (P < 0.05). In REC, male subjects reported significantly higher vibration than female (P < 0.05). Majority respondents (72.5%) preferred the CON method. The perceived vibration, noise and discomfort were less apparent from the CON than the REC.

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.

Comparison of Apical Extrusion of Bacteria After Glide Path Preparation Between Manual K File, One G Rotary, and WaveOne Gold Glider Reciprocation Preparations

Objective:

To compare the amount of apically extruded bacteria between hand-filed preparations, rotary and reciprocation glide path preparations in curved canals of extracted teeth infected with Enterococcus faecalis.

Methods:

Forty mandibular first molar teeth were decoronated, fitted into rubber stoppers and fixed onto glass vials. The mesiobuccal canals from mandibular first molar teeth were infected with Enterococcus faecalis, then randomly assigned to one of five groups for glide path preparation: manual stainless-steel file (K-files), rotary file (One G), reciprocating file (WaveOne Gold Glider) and two control groups. After glide path preparation, 0.01 mL of saline was taken from the experimental vials. The solution was plated on tryptic soy agar and colonies of bacteria were counted as colony-forming units. The results were analysed statistically using Kruskal-Wallis and post hoc Mann-Whitney U tests.

Results:

The manual K-file group was associated with significantly more bacteria extrusion compared to the rotary and reciprocating groups (P<0.05). However, no significant difference occurred between rotary and reciprocation instruments.

Conclusion:

All instrumentation techniques resulted in a measurable amount of apical extrusion of bacteria. Manual K-files extruded the highest quantity of bacteria compared to One G rotary file and WaveOne Gold Glider reciprocation file during glide path preparation.

Postoperative pain after endodontic treatment of necrotic teeth with large intentional foraminal enlargement

Objectives

To evaluate postoperative pain after endodontic treatment of necrotic teeth using large intentional foraminal enlargement (LIFE).

Materials and Methods

The sample included 60 asymptomatic necrotic teeth (with or without chronic apical periodontitis), and a periodontal probing depth of 3 mm, previously accessed and referred to perform endodontic treatment. After previous procedures, the position and approximate size of the apical foramen (AF) were determined by using an apex locator and K flexo-files, respectively. The chemomechanical preparation was performed with Profile 04 files 2 mm beyond the AF to achieve the LIFE, using 2.5 mL of 2.5% NaOCl at each file change. The filling was performed by Tagger's hybrid technique and EndoFill sealer. Phone calls were made to all the patients at 24, 48 and 72 hours after treatment, to classify postoperative pain. Statistical analysis was performed by different tests with a significance level of 5%.

Results

Age, gender, periradicular status and tooth type did not influence postoperative pain (p > 0.05). Only 1 patient (1.66%) reported severe pain after 72 hours. Moderate pain was reported by 7, 4 and 3 patients after 24, 48 and 72 hours, respectively (p = 0.0001). However, paired analyses showed a statistically significant difference only between 24 and 72 hours (p = 0.04). Sealer extrusion did not influence the postoperative pain (p > 0.05).

Conclusions

Acute or moderate postoperative pain was uncommon after endodontic treatment of necrotic teeth with LIFE.

Trial Registration

The Brazilian Clinical Trials Registry Identifier: RBR-3r967t

Apical debris extrusion of full-sequenced rotary systems in narrow ribbon-shaped canals

The apically extruded debris caused by TruNatomy System (TRN), RACE EVO system (RE) and VDW Rotate (VR) systems in mandibular anterior teeth with ribbon-shaped root canals were compared. The root canals (n = 20 in each group) were irrigated with NaOCl 2.5%, and the extruded debris was collected at pre-weighted Eppendorf tubes. The amount of apically extruded debris (mg) and the treatment time (s) were recorded. Tukey pairwise comparisons were performed to compare groups with a 95% confidence level. VR had significantly less debris extrusion values and treatment time than RE and TRN (P < 0.05). Although no difference was observed between RE and TRN in terms of apically extruded debris (P > 0.05), a significant difference in favour of RE was observed in terms of treatment time (P < 0.05). All the instruments extruded debris at varying weights.

Glide path enlargement of curved molar canals using HyFlex EDM glide path file versus PathFile: a comparative study of preparation time and postoperative pain

Background

This randomized clinical trial aimed to compare the preparation time and severity of postoperative pain between HyFlex Electric Discharge Machine (EDM) glide path file (GPF) and PathFile.

Methods

Eighty patients whose molar teeth had at least one severely curved canal were treated by the same specialist. After access cavity preparation, the patients were randomly assigned to receive glide path enlargement with either HyFlex EDM GPF or PathFile. ProTaper Next X1 and X2 files were used to prepare the canals. The time of preparation was assessed and the severity of postoperative pain over the next 7 days was recorded. The preparation time and the postoperative pain scores were compared using the Linear Mixed Models (P ≤ 0.05).

Results

Glide path enlargement time was significantly shorter with HyFlex EDM GPF (27.828 ± 2.345 s) than with PathFile (48.942 ± 2.864 s) (P < 0.001). The highest postoperative pain score was recorded on the first day and the pain decreased over time in both groups. HyFlex EDM GPF group patients reported significantly less postoperative pain than PathFile group patients overall (P < 0.001).

Conclusions

Postoperative pain and glide path preparation time could be reduced by using HyFlex EDM GPF system.

Trial registration PKUSSNCT, PKUSSNCT-17B12, Registered 24 October 2017.

Comparison of the Torsional Resistance of 4 Different Glide Path Instruments

INTRODUCTION

The present study aimed to compare the torsional strength of the initial files of the Mtwo (VDW, Munich, Germany) and novel Rotate systems (VDW, Munich, Germany) with the ProGlider (Dentsply Sirona, Ballaigues, Switzerland) and R-Pilot (VDW) glide path instruments.

METHODS

The Mtwo (10/.04), ProGlider (16/.02), R-Pilot (12.5/.04), and Rotate (15/.04) glide path files were compared regarding their torsional strength, which was tested using a specially designed test device (N = 20). The data obtained were statistically analyzed at 5% significance level using 1-way analysis of variance and the post hoc Tukey test. The fragment surfaces and separated instruments were examined with ×50, ×100, and ×1000 magnification under a scanning electron microscope.

RESULTS

The R-Pilot group showed the highest torsional strength value among all groups (P < .05), whereas there was no significant difference between the torsional strength values of the Mtwo and ProGlider groups (P > .05). The Rotate group had the lowest torsional strength among all groups (P < .05). The Mtwo group showed the lowest angle of rotation among all groups (P < .05).

CONCLUSIONS

Although the R-Pilot glide path file exhibited the highest torsional strength in all groups, Rotate showed the highest angle of rotation. Differences in torsional resistance of the instruments may be associated with their manufacturing methods and design features.

Effect of intracanal cryotherapy on postendodontic pain: a systematic review and meta-analysis of randomized controlled trials

This systematic review aimed to qualitatively and quantitatively evaluate the effectiveness of cryotherapy in the reduction of postendodontic pain. The review question was, "What will be the success rate of cryotherapy technique among human patients with postendodontic pain?". The review protocol was framed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Six studies were included in the review, and quantification of five studies was performed through a meta-analysis. In the forest plot representation of the studies comparing the control and cryotherapy groups in terms of the success rate in the management of postendodontic pain, the combined risk ratio (RR) was 0.80 (95% CI: 0.56 to 1.13) with a P value of 0.20. Based on the quantitative analysis, it can be suggested that intracanal cryotherapy does not play a significant role in reducing postendodontic pain.

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.

Effects of different glide path techniques on the amount of extruded debris and preparation times during root canal preparation

Background. This study purposed to compare the effect of new single glide path files on extruded apical debris and total preparation times during root canal preparation with the WaveOne Gold system.

Methods. Thirty-six extracted human lower molar teeth with mesiobuccal canal curvature angles of 25‒35° were randomly splited to three groups. In group 1, the glide path was created with WaveOne Gold Glider (WGG) file at working length (WL); in group 2, the glide path was created with ProGlider file (PG); in group 3, the glide path was not performed. In all the groups, the root canals were shaped with WaveOne Gold Primary (WOG) reciprocating files at WL. Apically extruded debris during instrumentation was picked up into pre-weighed Eppendorf tubes. The weight of the dry extruded debris was calculated by subtracting the pre- and post-instrumentation weights of the tubes in each group. The total time elapsed during the canal preparation was calculated with a chronometer. The data were analyzed using one-way ANOVA and post hoc Tukey tests.

Results. The WGG/WOG group extruded significantly fewer debris than the WOG and PG/WOG groups (P<0.05). There was no significant difference between the WOG and PG/WOG groups (P>0.05). The WGG/WOG and PG/WOG groups were significantly faster than the WOG group.

Conclusion. The amount of debris extruded apically significantly diminished when conventional WGG was implemented before using WOG. The total preparation time significantly diminished when the WOG file was used in combination with reciprocating and rotary glide path preparation techniques.

Comparative Evaluation of Quality of Obturation and Its Effect on Postoperative Pain between Pediatric Hand and Rotary Files: A Double-blinded Randomized Controlled Trial

Background

One of the cardinal points to be considered during endodontic procedures in children is the measure of postoperative pain.

Aim and objective

To evaluate the quality of obturation and its effect on postoperative pain with three file systems in primary mandibular molars during 1 week follow-up.

Materials and methods

The study was conducted as a double-blinded randomized controlled trial. The participants between 6 years and 9 years old requiring a pulpectomy were recruited for the trial. Forty-five primary mandibular molars were randomly allocated into 15 teeth each in Hand K-files; Kedo-SH and Kedo-SG Blue groups. Wong Baker's FACES Pain Rating Scale was used for assessing the postoperative pain in the children for 1 week. Pearson's Chi-square test, Kruskal-Wallis test, and Mann-Whitney U test were used for analyzing the data statistically.

Results

Optimal fillings were observed more in the Kedo-SG Blue group (80.0%) compared to the other two groups (p < 0.017). On intergroup analysis, the Kedo-SG Blue group reported less postoperative pain compared to Kedo-SH group on day 1 while on day 7 no postoperative pain was experienced in either of the groups. Less postoperative pain was reported by the children in whom the canals were optimally filled compared to overfilling and underfilling.

Conclusion

Kedo-SG Blue resulted in less postoperative pain when compared to Kedo-SH and hand K-files, whereas optimally filled children experienced less postoperative pain compared to overfilling and underfilling.

Clinical significance

A felicitous pediatric dental practice includes appropriate assessment and management of postoperative pain in children. Hence, the present study is important in highlighting the affiliation of postoperative pain with quality of obturation following an endodontic intervention in children.

How to cite this article

Jeevanandan G, Govindaraju L, Subramanian EMG, et al. Comparative Evaluation of Quality of Obturation and Its Effect on Postoperative Pain between Pediatric Hand and Rotary Files: A Double-blinded Randomized Controlled Trial. Int J Clin Pediatr Dent 2021;14(1):88-96.

Advancement of Mechanical Properties of Nickel-Titanium Rotary Endodontic Instruments by Spring Machining on the File Shaft

Nickel-titanium (NiTi) endodontic rotary instruments are used extensively in root canal procedures by both general dentists and specialists. However, their vulnerability to fracture is the major reason for clinicians' concern regarding their use. The objective of this study was to investigate the potential effects of spring machining of the file shaft on the fatigue and torsional resistances of NiTi rotary instruments. Three types of NiTi rotary systems with (S) and without (NS) spring machining were used in this study (n = 15 each): a spring file (SPR; #25/.06, SPR-S, SPR-NS), a ProTaper Next X2 (PTN; #25/variable taper, PTN-S, PTN-NS), and a ProTaper Gold F2 (PTG; #25/variable taper, PTG-S, PTG-NS). Spring machining was adjusted on the 6 mm of each file system's shaft via a laser cutting process. The number of rotation cycles until fracture (i.e., cyclic fatigue resistance), ultimate torsional strength, the distortion angle, and the toughness of each subgroup were estimated with specially designed devices. The results were analyzed using a paired t-test at a significance level of 95%. NiTi rotary instruments with spring machining exhibited a higher cyclic fatigue resistance than instruments without spring machining. The groups with spring machining exhibited a higher toughness and larger distortion angle than the groups without it (p < 0.05). In conclusion, spring machining on the shank of NiTi instruments may provide a stress-bearing area and attenuate the torsional and cyclic fatigue of NiTi rotary instruments.

The top risk factors for endodontic flare-up: a Monte Carlo simulation

OBJECTIVES

The aim of this study was to analyze the strength of risk factors related to endodontic flare-ups and rank them in order of their importance MATERIALS AND METHODS: A systematic literature search of PubMed, Cochrane Central Register of Controlled Trials, Scopus, and ISI Web of Knowledge, and grey literature was conducted up to November 2019. One hundred ninety-eight publications were identified. Twelve records fulfilled the eligibility criteria, and eight significant risk factors for flare-up, namely, "Periapical lesion," "multiple-visit treatment," "preoperative pain," "necrotic teeth," "female gender," "retreatment," "percussion pain," and "analgesics," were selected to construct the simulation model. The final data pool was established by the integration of data of common risk factors in the included articles. Monte Carlo method was used to analyze of combined numerical data, for simulation of the risk factor impacts. Ten thousand iterations were generated in the simulation model.

RESULTS

The results of the simulation revealed that the risk estimates of the factors had varying ranges of influence and probability on the flare-up risk. "Periapical lesion" was found to be the most sensitive risk factor, following by "preoperative pain" which was ranked the second place. The third-ranked risk factor was "multiple-visit treatment." The least sensitive risk factors for endodontic flare-up were "retreatment," "female gender," "necrotic teeth," and "analgesics."

CONCLUSIONS

The present study provides better comprehension on the importance of risk factors for flare-up based on their risk estimates.

CLINICAL RELEVANCE

A Monte Carlo simulation was adopted to identify the most influential risk factors for endodontic flare-up with a ranking, which can be used to provide meaningful predictions and further insights into clinicians' perception of flare-up risk.

Glide Path with Reciprocating Driven Pathfinding Instrument: Performance and Fracture Rate

INTRODUCTION

This study assessed the number of mesial and distal canals of mandibular molars in which the R-Pilot pathfinding reciprocating instrument reached the working length (WL) during macro glide path procedure. Fracture and deformation rates were also evaluated.

METHODS

One hundred fifty-six root canals of 52 teeth were scouted to the length of the apical foramen. Then the R-Pilot instrument was positioned at the canal orifice and activated. The instrument was moved by using a pecking motion and light apical pressure. This procedure was repeated in an attempt to reach the WL. The type of fracture and/or instrument deformation was assessed by scanning electron microscopy, whereas the roots with fractured instruments were scanned through micro-computed tomography. The percentage frequency distribution of fractures, deformations, and root canals in which the R-Pilot reached the WL were recorded and statistically compared by using the Pearson's χ² test with α = 5%.

RESULTS

R-Pilot instruments reached the WL in 139 root canals (89.10%), and χ² test showed a significant difference between the observed frequencies and the expected frequencies (χ² = 95.41, P = .000). The observed frequencies of fractures (2.56%) and deformations (1.92%) were also significantly lower than the expected (fracture: χ² = 140.41, P = .000; deformation: χ² = 144.23, P = .000). Fractures occurred mostly at the apical and curved parts of the root canals.

CONCLUSIONS

R-Pilot reached the WL in 89.10% of the root canals of mandibular molars with fracture and deformation rates of 2.56% and 1.92%, respectively.

Apically extruded debris produced during glide path preparation using R-Pilot, WaveOne Gold Glider and ProGlider in curved root canals

The present study aimed to compare the apically extruded debris produced during glide path preparation using R-Pilot (RP), WaveOne Gold Glider (WGG) and ProGlider (PG) with the subsequent preparation using Reciproc Blue in curved root canals. Mesial roots of mandibular molars with angle of curvature between 25° and 35° were selected (n = 20). The Myers and Montgomery method was used to collect and assess apically extruded debris. The glide path was prepared either manually with K-file, ProGlider, R-Pilot or WaveOne Gold Glider. Manual preparation group produced the highest amount of apically extruded debris (P < 0.05), while all groups caused debris extrusion. There were no significant differences among the extruded debris caused by RP, PG and WGG groups (P > 0.05). Apically extruded debris produced by engine-driven reciprocational or continuous rotational single file glide path instruments was similar, whereas manual glide path preparation was associated with the greatest amount of extruded debris.

Effect of occlusal reduction on postendodontic pain: A systematic review and meta-analysis of randomised clinical trials

The purpose of this systematic review was to assess the effect of occlusal reduction on post-operative pain following root canal treatment and was performed in accordance with the PRISMA statement being registered in the PROSPERO database (CRD42018089941). Two reviewers independently conducted a systematic literature search in the PubMed (MEDLINE), Dentistry & Oral Sciences Source and the Cochrane Library databases. Seven studies were included, of which three were used to perform meta-analysis for 6 days post-operative and the rest for qualitative synthesis. Three studies were assessed as low risk of bias, three as some concern, and one as high risk of bias. Occlusal reduction diminishes the post-operative pain (SMD -1.10 (95%CI -2.06, -0.15) I2  = 96.9%) at 6 days for teeth diagnosed as irreversible pulpitis, and, overall, likely reduces post-operative pain for patients presenting with irreversible pulpitis and/or symptomatic apical periodontitis. Future high-quality clinical trials are needed to better understand the role of occlusal reduction.

Influence of glide path kinematics during endodontic treatment on the occurrence and intensity of intraoperative and postoperative pain: a systematic review of randomized clinical trials

BACKGROUND

Preliminary canal enlargement (glide path preparation) may play a significant role in the development of pain. The aim of this systematic review of randomized clinical trials was to assess the influence of glide path kinematics during endodontic treatment on the occurrence and intensity of intraoperative and postoperative pain.

METHODS

A search was performed in June 2019 in six electronic databases (PubMed, Scopus, LILACS, SciELO, Embase and Web of Science) and two grey literature databases (OpenGrey and OpenThesis). The bibliographic references of the eligible articles were also hand-searched. The included clinical studies assessed the occurrence and intensity of intraoperative and/or postoperative pain after root canal preparation without glide path preparation (WGP) or with glide path preparation using manual (M-GP), continuous rotary (CR-GP), or reciprocating (R-GP) instruments. The primary outcome was the occurrence and intensity of intraoperative and postoperative pain, while analgesic consumption was the secondary outcome. The full texts of the eligible studies were analyzed by two reviewers who performed calibration exercises to verify the risk of bias and quality of the individual studies using the Joanna Briggs Institute Critical Appraisal tool.

RESULTS

From 1283 identified articles, only six studies were included in the qualitative analysis of the results, with a total sample of 884 patients/teeth. Three studies presented a high risk of bias, while three studies presented a moderate risk. Two studies reported that CR-GP causes lower pain levels than M-GP and WGP, and three studies showed no differences between CR-GP and R-GP. Regarding analgesic consumption, two studies found no differences among glide path kinematics, and one study reported lower consumption for CR-GP than for M-GP. Because of the limited number of studies and methodological differences, no statistical analyses were performed for the glide path kinematics comparisons.

CONCLUSIONS

Compelling evidence indicating a significantly different occurrence and intensity of pain among glide path kinematics is lacking. The systematic review protocol was registered in the PROSPERO database [CRD42020139989].

Buckling Resistance of Various Nickel-Titanium Glide Path Preparation Instruments in Dynamic or Static Mode

INTRODUCTION

The aim of this study was to compare the buckling resistance of nickel-titanium (NiTi) instruments for glide path preparation depending on the test mode (static vs dynamic).

METHODS

The conventional PathFile (PF; Dentsply Sirona, Ballaigues, Switzerland) and heat-treated ProGlider (PG, Dentsply Sirona) and WaveOne Gold Glider (WG, Dentsply Sirona) were evaluated. The instrument tips were placed in a small dimple prepared in an aluminum cube in a customized device. The file was then pushed in the axial direction at a 1.0-mm/s crosshead speed with rotation (dynamic mode) or without rotation (static mode). The dynamic mode of WG used its dedicated reciprocating rotation, whereas the others were rotated continuously at 300 rpm. The axial load and lateral buckling displacement were simultaneously measured. Data were analyzed statistically using 2-way analysis of variance (P = .05).

RESULTS

The buckling resistance in the dynamic mode was higher than in the static mode for PG and WG (P < .05), whereas PF was not influenced by test modes (P > .05). In the dynamic mode, the PG required the highest buckling load followed by PF and WG (P < .05). In the static mode, the WG showed the lowest load (P < .05). The dynamic mode showed significantly more upper level lateral buckling displacement than in the static mode (P < .05).

CONCLUSIONS

When the glide path preparation instruments moved in the dynamic mode as in clinical situations, the buckling resistance of the heat-treated NiTi glide path instruments was higher than in the static condition. The heat-treated instruments may have better buckling resistance than the conventional NiTi instrument in clinical situations.

Influence of Negotiation, Glide Path, and Preflaring Procedures on Root Canal Shaping-Terminology, Basic Concepts, and a Systematic Review

INTRODUCTION

Negotiation, glide path, and preflaring are essential steps in root canal shaping procedures. This report aimed to discuss the terminology, basic concepts, and clinical considerations of negotiation, glide path, and preflaring procedures and the influence of these steps on root canal shaping.

METHODS

This systematic review was undertaken following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The protocol has been registered with the International Prospective Register of Systematic Reviews (number CRD42019127021). A comprehensive literature search was performed by 2 independent reviewers using a selected search strategy in 2 electronic databases (PubMed and Scopus) until January 28, 2019. A further search was performed manually in endodontic journals. Studies investigating or comparing at least 1 shaping property resulting from root canal instrumentation with a glide path or preflaring in human extracted teeth or clinical studies were included.

RESULTS

The literature shows that the definition of glide path and preflaring procedures remains controversial, which requires an elaboration in the American Association of Endodontists' Glossary of Endodontic Terms. After the removal of irrelevant and duplicated articles, 98 articles were included. The impact of glide path preparation and preflaring on working length determination, apical file size determination, canal transportation, separation of endodontic files, shaping time, dentinal microcrack formation, and extrusion of debris was discussed. Because of heterogeneity among the included studies, quantitative synthesis was not performed for most of the parameters.

CONCLUSIONS

An evidence-based guideline is needed to define and correlate the basic concepts and current applications of each step of contemporary advancements in root canal instruments. Glide path preparation reduces the risk of debris extrusion, has no influence on the incidence of dentinal crack formation, and improves the preservation of the original canal anatomy. The creation of a glide path may have no impact on Reciproc files (VDW, Munich, Germany) in reaching the full working length. Preflaring increases the accuracy of working length determination. Further randomized clinical trials are required to evaluate the effect of a glide path and preflaring on root canal treatment outcomes.

Comparison of postoperative pain intensity after using reciprocating and continuous rotary glide path systems: a randomized clinical trial

Objectives

The aim of this study was to compare postoperative pain intensity after root canal treatment with One G (OG) vs. R-Pilot (RP) files used for glide path preparation.

Materials and Methods

Ninety-three single-canaled mandibular premolar teeth with asymptomatic non-vital pulp were randomly assigned into 3 groups (n = 31): OG, RP, or without glide path (WGP). After creating the glide path, the root canals were prepared using sequential Mtwo rotary files to size 30/0.05. One endodontic specialist carried out single-visit endodontic treatment. The patients were asked to rate the severity of postoperative pain on a visual analogue scale at 24, 48, and 72 hours after the visit. They were also asked to record their intake of prescribed analgesics taken. The data were analyzed using the χ², Friedman, Kruskal-Wallis, and Mann-Whitney U tests.

Results

In all 3 groups, postoperative pain decreased significantly at each time interval (p < 0.05). At 24 hours, the OG group had less postoperative pain than the WGP group (p < 0.05). However, no significant difference was found between the RP group and the others. No statistically significant difference was found among the WGP, OG, and RP groups in postoperative pain intensity at 48 or 72 hours or in analgesic tablet intake at the 3 assessed time intervals.

Conclusions

The OG group had less postoperative pain than the WGP group in the first 24 hours. The OG and RP systems were similar regarding postoperative pain intensity and analgesic intake.

Effective Establishment of Glide-Path to Reduce Torsional Stress during Nickel-Titanium Rotary Instrumentation

This study compared the torque generation during canal shaping with a nickel-titanium endodontic instrument according to the extent of glide-path establishment. Seventy-five simulated S-shaped canal blocks were divided into five groups (n = 15) according to the number of repetitive insertions to the working length using a One G glide-path instrument: groups with 5, 10, 15, and 20 insertions as well as group Z without glide-path establishment. When the tip of the One G file reached the working length, the file was moved back and forth repetitively at the working length for the designated number of times for each group. The instrumentation procedure with HyFlex EDM had 15 pecking strokes. During instrumentation, the generated torque was transmitted to a customized data acquisition module and collected using customized software. Data were computed to determine the maximum torque and total stress. The maximum screw-in forces were statistically analyzed using one-way analysis of variance and Tukey’s post hoc comparison test with a significance level of 95%. While the maximum stress did not have significant differences among the five groups (p > 0.05), groups with more than 10 repetitive insertions generated lower total stress during instrumentation than did the group with 5 insertions and group Z (p < 0.05). Under the limitations of this study, repetitive insertions of glide-path establishment files at the working length reduced stress generation during the shaping using nickel-titanium instruments.

In vivo evaluation of painful symptomatology after endodontic treatment with or without the use of photodynamic therapy

Context:

Postoperative pain control after endodontic treatment is important to maintain patient comfort.

Aim:

The aim of this prospective clinical study was to evaluate the postoperative symptomatology of endodontic treatments performed in a single session, with or without photodynamic therapy (PDT), using Reciproc #40 file in necrotic unirradicular anterior teeth.

Materials and Methods:

In a prospective clinical study, 40 teeth indicated for endodontic treatment were treated by a single endodontist according to a preestablished protocol. The teeth were randomly divided into two groups (n = 20): control group (CG) and laser group (LG). After 24 h, 72 h, and 1 week of endodontic treatment, patients' pain symptomatology was evaluated through a Visual Analog Scale (VAS) ranging from 0 to 10, in which 0 corresponds to no pain and 10 indicates extreme pain. In both workgroups, similar protocols were used for instrumentation with the Reciproc system (R40), irrigation with 2.5% sodium hypochlorite, and filling by the gutta-percha plastification technique, in which the CG did not use PDT, and the LG used PDT after the instrumentation sequence. After the visit, the patients were given a prescription for ibuprofen 400 mg to be taken every 6 h if they experienced pain.

Results:

The results of the study, analyzing the VAS, did not show any difference in pain symptoms between the groups at 24 h, 72 h, and 1 week (P > 0.05).

Conclusions:

It was concluded that there was no statistical difference between the groups.

Mechanical Properties of Orifice Preflaring Nickel-titanium Rotary Instrument Heat Treated Using T-Wire Technology

INTRODUCTION

This study examined whether the use of T-Wire heat treatment enhanced the resistance to torsional force, cyclic fatigue, and bending stiffness of orifice preflaring nickel-titanium instruments.

METHODS

Ninety heat-treated OneFlare (OFT; Micro-Mega, Besançon, France) and conventional OneFlare (OFC, Micro-Mega) nickel-titanium files of size #25/.09 with identical geometries were selected (n = 15 per group for each test). Torsional resistance was evaluated through the measurement of ultimate torsional strength, distortion angle, and toughness during rotational loading. Cyclic fatigue resistance was evaluated through measurement of the number of cycles to failure for each instrument. Stiffness was evaluated by observation of the bending moment on attaining a 45° bend. Independent t tests were performed for statistical analysis. After torsional and cyclic fatigue tests, all fractured fragments were examined under a field emission scanning electron microscope to observe characteristics of the fractured surfaces.

RESULTS

OFT showed better cyclic fatigue resistance and lower bending stiffness than OFC (P < .05); however, OFT and OFC did not differ significantly in terms of torsional resistance. The fractured cross-sectional surfaces had characteristics typical of cyclic fatigue and torsional fractures.

CONCLUSIONS

The OFT instruments made using T-Wire heat treatment had better cyclic fatigue resistance and lower bending stiffness with no decline in torsional strength.

Effects of Various Cryotherapy Applications on Postoperative Pain in Molar Teeth with Symptomatic Apical Periodontitis: A Preliminary Randomized Prospective Clinical Trial

INTRODUCTION

The purpose of the study was to evaluate the effects of intracanal, intraoral, and extraoral cryotherapy on postoperative pain in molar teeth with symptomatic apical periodontitis.

METHODS

A total of 100 patients were randomly distributed into 4 groups: control (without cryotherapy application), intracanal cryotherapy application, intraoral cryotherapy application, and extraoral cryotherapy application. The postoperative pain of the patients was recorded at the first, third, fifth, and seventh days. The data were statistically analyzed by using linear regression, χ², one-way analysis of variance, Tukey post hoc, and Kruskal-Wallis H tests (P = .05).

RESULTS

There were no statistically significant differences among the groups in terms of demographic data (P > .05). The preoperative pain levels and preoperative visual analogue scale (VAS) scores of pain on percussion were similar among the groups (P > .05). The linear regression analysis demonstrated that group variable had the most significant effect on postoperative pain at day 1 (P < .001) among the other variables (group, age, gender, tooth number, preoperative pain levels, and VAS scores of pain on percussion). When compared with the control group, all the cryotherapy groups exhibited less percussion pain and less postoperative pain at the first, third, fifth, and seventh days (P < .05).

CONCLUSIONS

Within the study limitations, all the cryotherapy applications (intracanal, intraoral, and extraoral) resulted in lower postoperative pain levels and lower VAS scores of pain on percussion versus those of the control group.

Comparison of apical extrusion of intracanal bacteria by various glide-path establishing systems: an in vitro study

OBJECTIVES

This study compared the amount of apically extruded bacteria during the glide-path preparation by using multi-file and single-file glide-path establishing nickel-titanium (NiTi) rotary systems.

MATERIALS AND METHODS

Sixty mandibular first molar teeth were used to prepare the test apparatus. They were decoronated, blocked into glass vials, sterilized in ethylene oxide gas, infected with a pure culture of Enterococcus faecalis, randomly assigned to 5 experimental groups, and then prepared using manual stainless-steel files (group KF) and glide-path establishing NiTi rotary files (group PF with PathFiles, group GF with G-Files, group PG with ProGlider, and group OG with One G). At the end of canal preparation, 0.01 mL NaCl solution was taken from the experimental vials. The suspension was plated on brain heart infusion agar and colonies of bacteria were counted, and the results were given as number of colony-forming units (CFU).

RESULTS

The manual instrumentation technique tested in group KF extruded the highest number of bacteria compared to the other 4 groups (p < 0.05). The 4 groups using rotary glide-path establishing instruments extruded similar amounts of bacteria.

CONCLUSIONS

All glide-path establishment instrument systems tested caused a measurable apical extrusion of bacteria. The manual glide-path preparation showed the highest number of bacteria extruded compared to the other NiTi glide-path establishing instruments.

Cyclic fatigue resistance of R-Pilot, HyFlex EDM and PathFile nickel-titanium glide path files in artificial canals with double (S-shaped) curvature

AIM

To examine the cyclic fatigue resistances of R-Pilot, HyFlex EDM and PathFile NiTi glide path files in S-shaped artificial canals.

METHODOLOGY

Twenty R-Pilot (12.5/.04), 20 HyFlex EDM (10/.05) and 20 PathFile (19/.02) single-file glide path files were included. Sixty files (n: 20/each) were subjected to static cyclic fatigue testing using double-curved canals until fracture occurred (TF). The number of cycles to fracture (NCF) was calculated by multiplying the rpm value by the TF. The length of the fractured fragment (FL) was determined by a digital microcaliper. Six samples of fractured files (n: 2/each) were examined by SEM to determine the fracture mode. The NCF and the FL data were analysed using one-way anova, post hoc Tamhane and Kruskal-Wallis tests using SPPS 21 software. The significance level was set at 5%.

RESULTS

In the double-curved canal, all the files fractured first in the apical curvature and then in the coronal curvature. The NCF values revealed that the R-Pilot had the greatest cyclic fatigue resistance, followed by the HyFlex EDM and PathFile in both the apical and coronal curvatures (P < 0.05).

CONCLUSIONS

R-Pilot NiTi glide path files, used in a reciprocating motion, had the greatest cyclic fatigue resistance amongst the tested NiTi glide path files in an artificial S-shaped canal.