Apical Debris Extrusion with Conventional Rotary and Reciprocating Instruments

Introduction: The aim of the present study was to compare the amount of apical debris extrusion after preparation using hand files, reciprocating files, and full rotary nickel-titanium systems. Methods and Materials: One hundred extracted human mandibular molars with two separated canals in mesial root were divided into five groups and prepared using reciprocating systems (Reciproc and Safesider endodontic reamer files), full rotary systems (Mtwo and Neoniti A1 files) and hand instrumentation systems. Endodontic access was prepared and a #15 K-file was passed beyond the apex of the mesiobuccal canal by 1 mm to ensure the canal patency. All mesiobuccal canals were prepared 1 mm shorter than the anatomic apex. In each case, extruded debris was collected in an Eppendorf tube and weighed after desiccation. The mean weight of extruded material was calculated in each group. The analysis was carried out using the Kruskal–Wallis test followed by two tailed and Mann-Whitney U test at a significance level of 0.05. The Bonferroni correction was also applied to correct multiple comparisons. Results: There was a statistically significant difference between the reciprocal and other techniques in debris extrusion (P<0.05). The order of groups ranked in terms of debris extrusion from the lowest to highest was as follows: 1) Hand instrumentation group (with crown down technique), 2) Mtwo group, 3) Neoniti A1 group, 4) Safesider endodontic reamer group, and 5) Reciproc group. Conclusion: Based on this in vitro study, all systems have some apical debris extrusion; however, using the hand instrumentation system resulted in extrusion of significantly less debris compared to the Reciproc group. It seems that hand and rotary instrumentation systems are better than reciprocating instrumentation systems in terms of the amount of debris extrusion.Keywords: Endodontics; Root Canal Preparation; Rotary Instrumentatio

Difference between the Actual and Labeled Concentrations of Several Domestic Brands of Sodium Hypochlorite

Introduction: Sodium hypochlorite (NaOCl) is extensively used in root canal treatment and its efficacy depends on the concentration of free available chlorine (FAC). This study aimed to assess the chlorine content of 10 domestically manufactured household bleach products available in the Iranian market and evaluate the effect of temperature, time and daily bottle uncapping on FAC concentration and pH of these products. Methods and Materials: One-liter bottles of 10 available brands of household bleach (n=4 of each brand) were collected and randomly divided into four groups (n=10). Two groups were refrigerated at 4°C while the remaining two were stored at room temperature. One group of refrigerated and one group of room temperature samples were subjected to daily bottle uncapping followed by agitation and recapping for 3 months (six times a week to simulate weekly office work). The remaining bottles remained untouched and served as controls. The concentration of FAC in each sample was measured using the iodometric titration assay, and the pH was measured using a calibrated pH-meter at baseline and 1, 2 and 3 months. The results were analyzed using the one-way ANOVA and t-test. Results: The mean concentration of FAC in the solutions was 4.87±0.19% at baseline. The measured concentration of sodium hypochlorite was different from the labeled value. The concentration of FAC decreased over time in all samples; the greatest reduction occurred in room temperature samples subjected to daily uncapping while the smallest reduction occurred in refrigerated, capped bottles (19% and 1.9%, respectively). The pH of all products decreased over time. The mean reduction in pH was 1.1 for the samples stored at room temperature for 3 months and 0.8 for the refrigerated samples. Conclusion: This in vitro study showed that the expected concentration of sodium hypochlorite solution made of household bleach for endodontic purposes is different from its actual concentration.Keywords: Chlorine Compounds; Hydrogen-ion Concentration; Root Canal; Sodium Hypochlorite

Cytotoxicity of Various Endodontic Materials on Stem Cells of Human Apical Papilla

Introduction: This in vitro study assessed and compared the cytotoxicity of mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) cement, Biodentine (BD) and octacalcium phosphate (OCP) on stem cells of the human apical papilla (SCAP). Methods and Materials: SCAPs were isolated from two semi-impacted third molars. The cells were cultured in wells of an insert 24-well plate and were then incubated. The plates were then removed from the incubator and randomly divided into four experimental groups that were exposed to 1-mm discs of set MTA, CEM, BD or OCP, and one untreated control group. After 24, 48 and 168 h, the plates were removed from the incubator and 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) solution was added to each well. Data were analyzed at different time points using the repeated measures ANOVA followed by Bonferroni test and the level of significance was set at 0.05. Results: Cytotoxicity of the four materials was not significantly different from that of the control group at 24, 48 and 168 h (P>0.05). Two-by-two comparison revealed that cytotoxicity of MTA and CEM cement was significantly different from each other at 168 h (P<0.05) although the cytotoxicity of CEM was less than MTA. Cytotoxicity of OCP and MTA was also significantly different from each other at 48 h and OCP had more favorable biocompatibility than MTA (P<0.05). Conclusion: CEM, OCP, BD and MTA showed acceptable biocompatibility when exposed to SCAP. Over time, CEM showed the least cytotoxicity among the materials under study.Keywords: Biodentine; Calcium-Enriched Mixture; Cytotoxicity; Endodontic Biomaterials; Mineral Trioxide Aggregate; MTT Assay; Stem Cells of Apical Papill

Endodontic and Surgical Management of Iatrogenic Root Injury Caused by Orthodontic Miniscrew Placement: A Case Report

One of the potential serious complications, associated with the inter-radicular placement of an orthodontic miniscrew, is root injury. This article reports the endodontic and surgical treatments of an iatrogenic root perforation in a mandibular first molar caused by the placement of an orthodontic miniscrew anchorage. The 24-month follow-up showed a successful treatment outcome.Keywords: Dental Root; Orthodontic Anchorage; Orthodontic Complication

Effect of Photobiomodulation on Pain Following Single Visit Non-surgical Root Canal Treatment of Molar Teeth with Symptomatic Irreversible Pulpitis

Objective: To assess the effect of Photobiomodulation (PBM) on post-endodontic pain of mandibular molar teeth with symptomatic irreversible pulpitis. Material and Methods: In this clinical trial, mandibular molars with symptomatic irreversible pulpitis underwent primary endodontic treatment in 90 systemically healthy patients. After root canal treatment, the patients were randomly divided into two groups of PBM with diode laser at 940 nm wavelength and 200 mW output power and placebo (mock PBM therapy). Level of pain was recorded at 6, 12, 24, 48, and 72 hours postoperatively using a visual analog scale (VAS). The data were analyzed using the Mann-Whitney test and the Kruskal-Wallis test. Results: The results showed that post-endodontic pain at all time points was significantly lower in the PBM group compared with the placebo group. The pain score in the PBM group was significantly lower than the placebo group (p<0.05). However, this difference was not significant at 48 h (p=0.18) and 72 h (p=0.12) postoperatively. Also, the results showed that the mean pain score in males and females in the PBM group was significantly lower than in males and females in the placebo group. Conclusion: Photobiomodulation can effectively decrease post-endodontic pain in mandibular molar teeth with symptomatic irreversible pulpitis

Comparison of Postoperative Pain after Root Canal Preparation with Two Reciprocating and Rotary Single-File Systems: A Randomized Clinical Trial

Introduction: Root canal preparation techniques may cause postoperative pain. The aim of the present study was to compare the intensity of postoperative pain after endodontic treatment using hand files, single file rotary (OneShape), and single file reciprocating (Reciproc) systems. Methods and Materials: In this single-blind, parallel-grouped randomized clinical trial a total of 150 healthy patients aged between 20 to 50 years old were diagnosed with symptomatic irreversible pulpitis of one maxillary or mandibular molars. The teeth were randomly assigned to three groups according to the root canal instrumentation technique: hand files (control), OneShape and Reciproc. Treatment was performed in a single visit by an endodontist. The severity of the postoperative pain was assessed by the visual analogue scale (VAS) after 6, 12, 24, 48 and 72 h. Data were analyzed using the Kruskal-Wallis and Mann-Whitney U tests. Results: The patients in control group reported significantly higher mean postoperative pain intensity at 12, 24, 48, and 72 h compared to the patients in the two other groups (P<0.05). There was no significant difference in mean intensity of postoperative pain between Reciproc and OneShape at 5 time points (P>0.05). Conclusion: The instrumentation kinematics (single-file reciprocating or single-file rotary) had no impact on intensity of postoperative pain.Keywords: Endodontic Treatment; Nickel-Titanium Instruments; Postoperative Pai

Canal transportation caused by one single-file and two multiple-file rotary systems: A comparative study using cone-beam computed tomography

Aim: This ex-vivo study aimed to compare canal transportation in mesio-buccal canal of mandibular first molars prepared with Mtwo and Revo-S multi-file and Neoniti single-file nickel–titanium (Ni–Ti) rotary systems using cone-beam computed tomography (CBCT). Methodology: CBCT scans were obtained from 60 extracted mandibular first molars and the teeth were randomly divided into three groups. Mesio-buccal canal of mesial root was prepared with Revo-S, Neoniti or Mtwo rotary systems according to the instructions of the manufacturers. Post-operative CBCT scans were also obtained. A single operator performed canal preparations while another operator blinded to the group allocation of teeth did the measurements. Data were analyzed using SPSS 20. The mean and standard deviation (SD) of the amount of canal transportation were calculated and compared between the groups using the Friedman test (P ≤ 0.05). Results: No significant difference was noted in canal transportation among the groups in the middle and apical third (P > 0.05). The rotary single-file instrument caused significantly greater canal transportation in the coronal third. Conclusion: No significant difference exists among different rotary systems in the amount of canal transportation caused in the middle and apical third of the mesio-buccal canal in mandibular first molars. Although all rotary files caused some degrees of canal transportation, the rotary single-file instrument caused significantly greater canal transportation than the multiple-file sequences in the coronal third. Riassunto: Obiettivi: Questo studio ex-vivo ha lo scopo di confrontare il trasporto canalare nel canale mesio-buccale di primi molari mandibolari preparati con i sistemi rotanti in nichel-titanio (Ni-Ti) Mtwo e Revo-S ed il sistema mono-strumento Neoniti, utilizzando la tomografia computerizzata a raggio conico (CBCT). Materiali e metodi: Le scansioni CBCT sono state ottenute in 60 primi molari mandibolari estratti e i denti sono stati suddivisi in tre gruppi. Il canale mesio-buccale della radice mesiale è stato preparato con sistemi rotanti Mtwo, Revo-S o Neoniti seguendo le istruzioni del produttore. Sono state quindi ottenute scansioni CBCT post-strumentazione. Un singolo operatore ha eseguito le preparazioni dei canali mentre un altro operatore ha effettuato le misurazioni. I dati sono stati analizzati utilizzando SPSS 20. La media e la deviazione standard (SD) della quantità di trasporto canalare sono stati calcolati e confrontati tra i gruppi usando il test Friedman (P ≤ 0.05). Risultati: Nessuna differenza significativa è stata osservata tra i gruppi nel trasporto dei canali nel terzo medio e apicale (P > 0.05), ma la tecnica mono-strumento ha causato un trasporto più significativo del canale nel terzo coronale. Conclusioni: Nessuna differenza significativa è stata riscontrata tra i diversi sistemi rotanti nella quantità di trasporto canalare nel terzo medio e apicale nel canale mesio-buccale di primi molari mandibolari. Anche se tutti i file rotanti hanno causato un certo grado di trasporto del canale, la tecnica mono-strumento rotante ha causato un trasporto del canale nel terzo coronale significativamente maggiore rispetto alle sequenze di file multipli. Keywords: Canal transportation, Nickel–titanium, Rotary files, CBCT, Parole chiave: Trasporto canalare, Nichel-titanio, Strumenti rotanti CBC

Applications of guided endodontics: A review article

Background and Aims: Guided endodontics is a new technique that is now evolving. It is used in many treatments, especially in access cavity preparation and locating root canals in teeth with pulp canal obliteration (PCO), microsurgical endodontics, and fiber post removal in retreatments. In addition, this technique is independent of operator experience, requires less treatment time for the patient, and is more precise and safer than conventional endodontics. This technique involves the use of cone beam computed tomography imaging (CBCT), tooth surface scanning, and special software to provide guidance for performing endodontic treatment in a fast, safe, and minimally invasive manner. This review article aims to introduce guided endodontics and to describe its technique, advantages, and limitations

Comparison of Bacterial Leakage between 3 Different Root Canal Obturation Techniques in Oval Shaped Canals

Introduction: The purpose of this study was to evaluate the sealing ability of 3 obturation techniques in oval-shaped canals by bacterial leakage assessment. Methods: Sixty mandibular incisors with oval canals were selected after providing buccolingual and mesiodistal radiographs. The teeth were sectioned at a 10 mm distance from the apex. After instrumentation, the teeth were divided into 3 groups and the canals in the three groups were obturated with lateral condensation (G1), warm vertical condensation (G2) and thermoplasticized injectable gutta percha (G3). The teeth were exposed to human saliva. Observing the turbidity of the BHI broth for a period of 63 days the number of days required for the complete contamination of root canals was recorded. The data were analyzed using descriptive statistical methods and Kruskal-Wallis test with SPSS statistical software. Results: Warm vertical condensation (G2) needed a significantly greater average time for leakage than the two other methods. No significant differences were found between lateral condensations and thermoplasticized injectable G.P techniques. Conclusion: warm vertical condensation provides a better seal against bacterial leakage than lateral condensation and obtura II method in obturating oval-canals

Mitochondrial DNA Copy Number Variations and Serum Pepsinogen Levels for Risk Assessment in Gastric Cancer

International audienceBackground: Variations in mtDNA-CN of PBLs, as a potential biomarker for GC screening has currently been subject to controversy. Herein, we have assessed its efficiency in GC screening, in parallel and in combination with sPG I/II ratio, as an established indicator of gastric atrophy. Methods: The study population included GC (n = 53) and non-GC (n = 207) dyspeptic patients. The non-GC group was histologically categorized into CG (n = 104) and NM (n = 103) subgroups. The MtDNA-CN of PBLs was measured by quantitative real-time PCR. The sPG I and II levels and anti-H. pylori serum IgG were measured by ELISA. Results: The mtDNA-CN was found significantly higher in GC vs. non-GC (OR = 3.0; 95% CI = 1.4, 6.4) subjects. Conversely, GC patients had significantly lower sPG I/II ratio than the non-GC (OR = 3.2; CI = 1.4, 7.2) subjects. The combination of these two biomarkers yielded a dramatic amplification of the odds of GC risk in double-positive (high mtDNA-CN-low sPGI/II) subjects, in reference to double-negatives (low mtDNA-CN-high sPGI/II), when assessed against non-GC (OR = 27.1; CI = 5.0, 147.3), CG (OR = 13.1; CI = 2.4, 72.6), or NM (OR = 49.5; CI = 7.9, 311.6) groups. Conclusion: The combination of these two biomarkers, namely mtDNA-CN in PBLs and serum PG I/II ratio, drastically enhanced the efficiency of GC risk assessment, which calls for further validations