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.

Influence of concentration, irrigation method, and root canal third on intratubular penetration of sodium hypochlorite - a broad statistical analysis.

Background: The permanence of microorganisms in the root canal system represents the main cause of endodontic failure. Considering the impossibility of effective action of the endodontic files in ramifications of the main canal and mainly inside the dentinal tubules, a better understanding of the irrigation dynamics to enhance endodontic prognosis is essential. Objective: To evaluate the depth of intratubular penetration values of sodium hypochlorite (NaOCl) (dependent variable) by comparing different concentrations, methods of irrigation, and root canal thirds (independent variables) and to investigate the existence of interactions among them, capable of influencing the dependent variable. Material and Methods: 40 roots from extracted human maxillary central incisors were stained and instrumented according to four irrigation protocols (n. 10): conventional irrigation (CI) at each use or change of instrument, and final irrigation with 5ml of 2.5% or 5.25% NaOCl, with or without passive ultrasonic irrigation (PUI), respectivelly. Measurements based on stereomicroscopic images were obtained, and the data were subjected to statistical analysis (p< 0.05). Results: The highest depth values of intratubular penetration of NaOCl were observed in the cervical third, at 5.25%, and by PUI. When only two independent variables were analyzed in association, the highest penetration depth values of NaOCl were obtained at 5.25%, regardless of irrigation method, at 5,25%, in the cervical third, and; in the cervical third, despite of irrigation method. Considering the three independent variables simultaneously, the highest depth values of intratubular penetration of NaOCl were observed in the cervical third, at 5.25%, no matter the irrigation method. The interaction between the independent variables on the penetration depth values of NaOCl was only confirmed considering the irrigation method and root canal third. Conclusions: Intratubular penetration of NaOCl was influenced by the three independent variables individually and when the irrigation method and root canal third were considered simultaneously. Key words:Dentinal tubules, Depth, Disinfection, Irrigation, Root canal system, Sodium hypochlorite.

Clinical determination of anatomical diameter in different dental groups correlating them with gender, age, tooth/canal and pulpoperiradicular diagnosis: an observational clinical study.

The aim of this observational clinical study (OCS) was to determine the clinical anatomical diameter (CAD) in several dental groups, thus correlating them with gender, age, tooth/canal and pulpoperiradicular diagnosis. Three-hundred fifty-nine teeth/584 vital or necrotic root canals from patients of both genders and different ages composed the sample. After performing the necessary previous procedures, K-Flexofiles were used to determine the CAD. Then, the gender and age of the patients, as well as the pulpoperiradicular diagnosis of the teeth were tabulated to conduct the statistical analysis (p < 0.05). Of the 359 teeth/584 root canals evaluated, 208/342 were from women (mean age 38.85 ± 13.42 years) and 151/242 were from men (mean age 45.41 ± 14.90 years). Statistically significant differences between the CAD means of root canals from women and men were not identified (p = 0.411). The analysis of the correlation between the CAD and age also showed a total independence (p = 0.271). Teeth with pulp necrosis and asymptomatic apical periodontitis diagnosed radiographically (TPNAAPDR) had a significantly larger CAD mean than teeth with pulp necrosis and no asymptomatic apical periodontitis diagnosed radiographically (TPNNAAPDR) and teeth with vital pulp and normal apical tissues (TVPNAT) (p = 0.0297); and the last two did not differ statistically (p > 0.05). The largest CAD mean was observed in single canals of maxillary central incisors. The lowest values of this variable were identified in the mesiobuccal and mesial canals of maxillary and mandibular first molars, respectively. The CAD of the root canals was influenced only by the root canal/tooth and pulpoperiradicular diagnosis.

Analysis of obtaining apical patency indexes during endodontic treatments considering gender, age, pulpoperiradicular diagnosis and canal/tooth-A clinical study.

This study aimed to perform an analysis of obtaining apical patency indexes during endodontic treatments considering gender, age, pulpoperiradicular diagnosis and canal/tooth (n. 639/383). Following previous clinical procedures, a thin K-File (No. 20, 15, 10 or 08) was used to achieve apical patency. These specific data and some demographic and clinical information were submitted to the statistical analysis (p < 0.05). Significant statistical differences were not identified considering gender (p = 0.156) and age (p = 0.793). However, in 14.6% of the canals of vital teeth and 14.1% of the canals of necrotic teeth without periapical lesions, apical patency could not be achieved, which occurred in only 7% of the canals of necrotic teeth with periradicular disease (p = 0.009). Considering canal/tooth, apical patency was more challenging to obtain in canals of posterior teeth (p = 0.000). The pulpoperiapical diagnosis and canal/tooth significantly influenced the obtaining of apical patency.

Incidence of fracture of ProDesign Logic system instruments: A cross-sectional retrospective study.

The aim of the present study was to analyze the incidence of fracture of ProDesign Logic system instruments in endodontic treatments performed by a specialist, in addition to identifying the dental group, arch, and the root canal thirds in which the fractures occurred more frequently. Digital radiographs and medical records were initially analyzed and resulted in the selection of 561 teeth (1302 canals) treated between 2018 and 2020, using the ProDesign Logic system instruments. These data were reassessed to determine the occurrence of fractures and identify the dental group and root canal thirds in which they occurred. Then, the data were statistically analyzed using the Fisher's Exact Test (p < 0.05). The general fracture rates were 8.5 and 3.69%, considering the number of teeth and canals treated, respectively. Mandibular first molars were the teeth most associated with the occurrence of fractures (19.1%). When the arches were compared, there was no statistical difference regarding the number of fractures in the different root canal thirds (p = 0.307). However, they were more frequent in the apical third in both arches (p = 0.000). The incidence of fracture of ProDesign Logic system instruments was relatively high and occurred more frequently in the apical third of molars.

Postoperative pain after endodontic treatment of necrotic teeth submitted to large apical preparation using oscillatory kinematics.

BACKGROUND: Regardless of the technique applied for chemomechanical preparation, postoperative pain is a very relevant matter in endodontics. Objective: To evaluate postoperative pain after endodontic treatment of necrotic teeth submitted to large apical preparation (LAP) using oscillatory kinematics. MATERIAL AND METHODS: The sample included 60 asymptomatic necrotic teeth with or without apical radiolucency, and with normal periodontal status, referred for endodontic treatment. Following initial procedures, the position and approximate size of the apical constriction were determined by using an apex locator and K Flexofiles, respectively. The chemomechanical preparation was conducted using oscillatory kinematics and 2.5ml of 2.5% NaOCl at each file change to achieve LAP, and the filling was done with Tagger's hybrid technique and EndoFill sealer. Phone calls were made to all the patients at 24, 48 and 72 hours after treatment to request their classification of postoperative pain, and data were submitted to statistical analysis. RESULTS: Only 3 patients (5%) reported severe pain after 72 hours. Moderate pain was reported by 17, 9 and 1 patient after 24, 48 and 72 hours, respectively (P = 0.000). However, paired analyses showed a statistically significant difference only between 24 and 72 hours (P = 0.001), and 48 and 72 hours (P = 0.014). Age and tooth type did not influence the postoperative pain, regardless of time (P> 0.05). After 72 hours, women experienced significantly more pain than men (P = 0.012), and teeth without periradicular lesion were more sensitive that teeth with perirradicular lesion (P = 0.027). CONCLUSIONS: Acute or moderate postoperative pain was uncommon after endodontic treatment of necrotic teeth submitted to LAP using oscillatory kinematics. Key words:Endodontic treatment, oscillatory kinematics, postoperative pain, pulp necrosis.

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.

Instrumentação foraminal: repercussões locais e sistêmicas / Foraminal enlargement: Local and systemic repercussions

Introdução: A infecção endodôntica pode alcançar a saída foraminal e, inclusive, ir além dela. Logo, a determinação da constrição apical como o limite ideal para instrumentação e obturação tem sido questionada. A instrumentação foraminal intencional é realizada com o intuito de diminuir o contingente microbiano a níveis mais favoráveis ao reparo. Entretanto, repercussões locais e sistêmicas estão associadas à sua execução. Objetivo: Realizar uma revisão crítica da literatura sobre repercussões locais e sistêmicas relativas à instrumentação foraminal intencional. Métodos: Em março de 2018, uma busca eletrônica realizada na base de dados PUBMED utilizando os termos "foraminal enlargement" OR "foraminal widening" OR "apical limit" AND "endodontics" identificou 74 artigos científicos. Esses artigos, a análise de suas referências bibliográficas e a utilização de mais 5 artigos base resultaram nos 111 estudos consultados para a realização dessa pesquisa. Resultados: A ampliação foraminal intencional nem sempre pode ser praticada em virtude de razões anatômicas e morfológicas. Quanto maior a ampliação do forame apical, maior a possibilidade de extravasamento de substâncias e/ou materiais utilizados para a realização do tratamento endodôntico. A instrumentação foraminal intencional parece ser contraindicada em pacientes que fazem ou fizeram uso de bisfosfonatos recentemente, com distúrbios de coagulação e/ou sob uso crônico de anticoagulantes e com alto risco de bacteremia. Conclusões: Os impactos da instrumentação foraminal intencional sobre o sucesso do tratamento endodôntico devem ser investigados. Contudo, os delineamentos metodológicos dos estudos clínicos devem ser cuidadosos, principalmente no tocante às condições sistêmicas dos pacientes que farão parte do universo amostral (AU).

Introduction: endodontic infection can reach and even go beyond the apical foramen. Therefore, determining apical constriction as the ideal limit for instrumentation and obturation has been questioned. Intentional foraminal enlargement is performed for the purpose of reducing the microbial contingent to levels more favorable to repair. However, local and systemic repercussions have been associated with this approach. Objectives: to critically review the literature on local and systemic repercussions relative to intentional foraminal enlargement. Methods: in March 2018, an electronic search performed on the PUBMED database using the terms "foraminal enlargement" OR "foraminal widening" OR "apical limit" AND "endodontics" identified 74 scientific articles. These articles, analysis of their references and use of another 5 base articles resulted in the 115 studies used for performing this research. Results: intentional foraminal enlargement cannot always be performed due to the anatomical and morphological conditions. The greater the apical foramen enlargement, the greater the possibility of extrusion of substances and/or materials used to perform endodontic treatment. Intentional foraminal enlargement seems to be contraindicated in patients who are taking or have recently used bisphosphonates, those with coagulation disorders and/ or under chronic use of anticoagulants and at high risk for bacteremia. Conclusions: the impacts of intentional foraminal enlargement on the success of endodontic treatment should be investigated. However, the methodological procedures of clinical studies should be carefully designed, especially taking into consideration the systemic conditions of patients who will be part of the sample (AU).

Smear layer removal by passive ultrasonic irrigation and 2 new mechanical methods for activation of the chelating solution.

OBJECTIVES: The aim of this study was to compare smear layer removal by conventional application (CA), passive ultrasonic irrigation (PUI), EasyClean (EC), and XP-Endo Finisher (XPF), using 17% ethylenediaminetetraacetic acid (EDTA) after chemomechanical preparation, as evaluated with scanning electron microscopy (SEM). MATERIALS AND METHODS: Forty-five single-rooted human mandibular premolars were selected for this study. After chemomechanical preparation, the teeth were randomly divided into 5 groups according to the protocol for smear layer removal, as follows: G1 (control): CA of distilled water; G2 (CA): CA of 17% EDTA; G3 (PUI): 17% EDTA activated by PUI; G4 (EC): 17% EDTA activated by EC; and G5 (XPF): 17% EDTA activated by XPF. SEM images (×1,000) were obtained from each root third and scored by 3 examiners. Data were evaluated using the Kruskal-Wallis and Dunn tests (p < 0.05). RESULTS: In the apical third, there were no statistically significant differences among the groups (p > 0.05). In the cervical and middle thirds, the experimental groups performed better than the control group (p < 0.05); however, G2 presented better results than G3, G4, and G5 (p < 0.05), which showed no differences among one another (p > 0.05). CONCLUSIONS: No irrigation method was able to completely remove the smear layer, especially in the apical third. Using CA for the chelating solution performed better than any form of activation.

Correlation among Root Canal Configuration, Quality of Filling, and Its Sealability.

OBJECTIVE: This study aimed to evaluate the existence of possible correlations among root canal configuration, quality of filling, and its sealability. MATERIALS AND METHODS: Sixty human mandibular central incisors were selected for this study. The teeth were prepared with the Profile 04 system up to instrument 35/0.04 and irrigated with 2.5 mL of 2.5% sodium hypochlorite at each instrument change. Root canal filling was performed by the lateral compaction technique, using gutta-percha and an epoxy resin-based sealer (AH Plus) labeled with 0.1% Rhodamine B dye. Afterward, the specimens were submitted to fluid filtration tests to assess the sealability of the filling. Cross-sections were obtained at -3, -6, and -8 mm from the root apex and submitted to a metallographic treatment to determine the root canal configuration and the percentage of gutta-percha filled areas. The data were statistically analyzed by the Grubbs test. Pairs of correlations were analyzed by applying the Spearman test at a level of significance of 5%. RESULTS: No correlation was observed among the analyzed variables as follows: root canal configuration versus filling quality (Spearman's rho = 0.031); filling quality versus sealability (Spearman's rho = 0.219); and root canal configuration versus sealability (Spearman's rho = 0.184). CONCLUSION: The root canal configuration did not affect the quality of the filling and its sealability.

Incidence of periodontal compromise in teeth indicated for undergoing endodontic treatment: A clinical study.

OBJECTIVE: The aim of this study was to evaluate the periodontal status of teeth indicated for undergoing endodontic treatment. MATERIALS AND METHODS: Two hundred and nine teeth were evaluated using probing depth tests at three vestibular and three palatine/lingual sites before the patients underwent treatment. Teeth that presented up to 3-mm probing depth were considered as healthy. Those that presented at least one site with probing depth >3 mm were considered periodontally compromised. The data were statistically analyzed by means of applying the Chi-square test, with a level of significance of 5%. RESULTS: Of the total of 209 teeth evaluated, 40 (19.10%) presented periodontal compromise. There was statistically significant difference related to the compromised teeth of patients of the female gender (22.80%) compared with teeth of patients of the male gender (12.30%) (P < 0.05). CONCLUSIONS: Fewer than 20% of the teeth evaluated presented a periodontal compromise. Patients of the female gender presented a higher number of periodontally compromised teeth than patients of the male gender.

Residual smear layer after root canal instrumentation by using Niti, M-Wire and CM-Wire instruments: A scanning electron microscopy analysis.

OBJECTIVE: The purpose of this study was to compare the amount of residual smear layer after root canal instrumentation by using Ni-Ti, M-Wire, and CM-Wire instruments. MATERIALS AND METHODS: Seventy-two mandibular incisors were randomly divided into six groups according to the system used: WaveOne (WO), Reciproc (RP), Unicone (UC), ProTaper Next (PN), Mtwo (MT), and HyFlex (HF). Afterward, the specimens were cleaved in the mesiodistal and buccolingual direction for analysis by scanning electron microscopy. RESULTS: Considering both directions and root canal thirds, there was no difference between HF, MT, and PN. RP, UC, and WO presented a significant difference between the directions, and the cervical third showed a significantly smaller quantity of residual smear layer compared with the apical third. When the systems were compared among them, there was a significant difference only between RP and WO. CONCLUSIONS: Residual smear layer observed after instrumentation with the different systems was similar, except for quantities between the reciprocating systems.

Postoperative Pain after Endodontic Retreatment Using Rotary or Reciprocating Instruments: A Randomized Clinical Trial.

INTRODUCTION: The aim of this randomized clinical trial was to evaluate the influence of rotary or reciprocating retreatment techniques on the incidence, intensity, duration of postoperative pain, and medication intake. METHODS: After power analysis calculations, 65 patients who needed endodontic retreatment were randomly assigned to 1 of 2 groups according to the instrumentation system used: Mtwo (VDW, Munich, Germany) or Reciproc (VDW). Retreatments were performed in a single visit by an endodontic specialist. Participants were asked to rate the incidence and intensity of the postoperative pain on a verbal rating scale 24, 48, and 72 hours after treatment. Patients were also asked to record the number of prescribed analgesic medication tablets (ibuprofen 400 mg) taken. A logistic regression analysis was used to assess both the incidence and duration of pain. Differences in the intensity of pain were analyzed using the ordinal (linear) chi-square test, and the Mann-Whitney U test was used to assess differences in the intake of analgesic medication between groups. RESULTS: No statistically significant difference was found among the 2 groups in relation to postoperative pain or analgesic medication intake at the 3 time points assessed (P > .05). Multivariate analysis showed a significantly higher incidence of pain after 24 hours when preoperative pain was present and a significantly longer duration of pain for men than women independently of the retreatment technique used. CONCLUSIONS: The reciprocating system and the continuous rotary system were found to be equivalent regarding the incidence, intensity, duration of postoperative pain, and intake of analgesic medication.

The Impact of Apical Patency in the Success of Endodontic Treatment of Necrotic Teeth with Apical Periodontitis: A Brief Review.

Accumulation of soft tissue or dentinal remnants in the apical region is a common event that can cause blockage of root canals. This event can be avoided if apical patency is performed during the root canal shaping procedures. However, there is no consensus on the role of apical patency in relation to the success of endodontic treatment of necrotic teeth with apical periodontitis. Therefore, the purpose of this paper was to conduct a brief review on the role of apical patency in guaranteeing the success of endodontic treatments of necrotic teeth with apical periodontitis considering two other key points; the root canal anatomy and microbiology.