Endodontic Access Cavity Research Articles

New insight into the role of electronic apex locators in detecting simulated horizontal root fractures: An In vitro study

Aim and Objectives: The aim of this study is to check the accuracy of two different electronic apex locators (EALs): Canal Pro and Root ZX – in locating simulated horizontal root fractures (HRFs). Materials and Methods: Forty-five recently extracted, single-rooted, human permanent teeth were selected for the study. Endodontic access cavity was prepared, and canal patency was checked using no. 10-K file. Horizontal fractures were simulated using 0.2-mm thick diamond disk in coronal, middle and/or apical third of root by operator one, until half of the canal was exposed circumferentially. Using both the apex locators, all the fractures were detected by the second operator to confirm the accuracy of EALs. The actual length of the fractures was then measured under ×2.5 magnification, and results were subjected to statistical analysis. Results: Results were analysed using the one-way analysis of variance and Tukey's post hoc test, and the differences between all the test samples were analysed. All the measurements were compared to the actual values separately. A statistically significant difference was determined at 95% confidence level (P ≤ 0.05). Conclusion: Investigated both the EAL are capable of detecting simulated HRF and that the Canal Pro showed a higher accuracy rate.

Comparative evaluation of apical extrusion of intracanal bacteria using four single-file NiTi instruments: An in vitro study

Introduction: A major objective in root canal treatment is to clean the root canal system. During the process, dentine chips, pulp tissue fragments, necrotic tissue, microorganisms, and intracanal irrigants may be extruded through the apical foramen. This in vitro study was conducted to evaluate the apical extrusion of Enterococcus faecalis with One Shape, F360, WaveOne, and Reciproc endodontic single-file systems. Materials and Methods: Seventy-five human single-rooted mandibular premolar teeth were selected. Endodontic access cavities were prepared. Pulp chamber was accessed, and a pure culture of E. faecalis was used to infect the root canals. Vials with rubber stoppers were selected as the test apparatus. Then, the samples were broadly divided into four main groups with a sample size of 15 teeth. Fifteen previously infected teeth were used as controls. All the root canals were instrumented with the size 25 instruments. A total volume of 2 ml of saline was used for each root canal as irrigant. After 24 h, colonies of bacteria were counted using classical bacterial counting technique as colony-forming units. Statistical Analysis: Data were analyzed statistically using Statistical Package for the Social Sciences, version – 21 (IBM Corp., NY) Software for Windows. Data were expressed in its mean and standard deviation. Results: The results indicated that all the four single-file systems tested caused a measurable apical extrusion of debris. Statistically, significant difference was observed between One Shape, F360, WaveOne, and Reciproc in terms of E. faecalis extrusion, P Conclusion: Within the limitations of the present study, it can be concluded that the reciprocating single-file systems extruded less amount of E. faecalis than compared to rotary single-file systems.

Decision criteria influencing the therapeutic approach to invasive cervical resorption: a case series.

Invasive cervical resorption (ICR) is a dental lesion starting in the cervical region and involving the loss of dental hard tissue as a result of odontoclastic action. Due to its localization and invasive pattern, this process represents a challenging clinical situation. When feasible, the major aim of an ICR treatment is to completely remove the pathologic tissue (specifically at the entry point of the lesion) and to seal the resulting defect, without compromising tooth rehabilitation. In this context, choosing how to access the resorptive lacuna is essential. Two main options have been described in the literature: an external approach, requiring the surgical exposure of the resorptive lacuna, and an internal approach, taking advantage of the endodontic access cavity. However, there are no guidelines that indicate which approach to choose for the treatment of an ICR. This article is based on four clinical cases. It aims to provide specific clinical and radiologic features that should be considered in order to take the most appropriate decision, when choosing between the internal and the external approaches. It is proposed to base the therapeutic strategy on the accessibility and the size of the portal of entry of the lesion. When the entry point is wide, its extension along the root must also be taken into account. Other important parameters are the circumferential and vertical extents of the lesion in the radicular dentin. Although it is not a determining factor, the pulpal involvement of the lesion can also be considered.

Computer-aided dynamic navigation: a novel method for guided endodontics.

To investigate the novel use of computer-aided dynamic navigation for guided endodontics. Dental casts were fabricated from sets of extracted human teeth. A cone beam computed tomography (CBCT) scan of each cast, with a molded thermoplastic stent and a radiographic marker attached, was obtained and imported into the planning software of a dynamic navigation implant surgery system. Simulating implant surgery but for guided endodontics, the drilling entry point, angle, pathway, and depth of virtual implants were planned for 29 selected teeth. The radiographic marker was replaced with a jaw tag and mounted in a phantom head. A drill tag was attached to the drill handpiece. Following calibration, guided by the stereoscopic motion-tracking camera via the tags and images on a computer monitor providing real-time dynamic plus visual intraoperative feedback, the handpiece was aligned accordingly and endodontic access cavity preparation carried out. Successful root canal location was confirmed using periapical radiographs and CBCT. Conservative access cavities were achieved and all the expected canals were successfully located in 26 teeth (n = 29). Due to tracking difficulties, only one canal was located in two maxillary second molars; in a maxillary first molar, only two canals were located and the access preparation for the third canal was misaligned and off-target. The results of this study demonstrate the potential of using computer-aided dynamic navigation technology in guided endodontics in clinical practice.

Ex vivo microbial leakage analysis of polytetrafluoroethylene tape and cotton pellet as endodontic access cavity spacers.

Background:The endodontic spacers are placed between the endodontic appointments or after completion of the endodontic therapy, and until the placement of a definitive restoration.Aims:The aim of this study was to evaluate the sealing ability of polytetrafluoroethylene (PTFE) access spacer against microbial leakage and to compare it with that of a cotton pellet.Materials and Methods:Fifty-two extracted human single-rooted premolars were divided into two experimental groups (n = 20) according to the endodontic spacer; cotton pellet or PTFE tape, and two control groups (n = 6). Following standardized access cavity, cleaning, and shaping procedures, the access cavities received a standardized thickness of the spacer material followed by a Cavit restoration in all the teeth except for the positive controls, which were left empty. Negative controls had the root surfaces completely sealed with nail polish. A dual-chamber microbial leakage model was used with Enterococcus faecalis as the test strain. At days 7 and 30, samples of the lower chambers' solution were obtained and subjected to the quantitative real-time polymerase chain reaction (qPCR) analysis to quantify bacterial levels. Furthermore, broth turbidity in the lower chambers was recorded weekly. The Mann–Whitney U test and Wilcoxon test were used to compare E. faecalis counts between and within groups, respectively.Results:At days 7 and 14, the experimental groups leaked similarly as determined by broth turbidity. However, at days 21 and 30, a significantly higher number of cotton pellet samples exhibited microbial leakage. Analysis by qPCR revealed higher levels of E. faecalis counts in cotton pellet samples compared with PTFE samples. This difference was statistically significant at day 7, but not at day 30.Conclusions:PTFE spacer showed improved sealing ability compared with the commonly used cotton pellet and may serve as an alternative endodontic access cavity spacer.

Presentation of gaps around endodontic access cavity restoration by phase contrast-enhanced micro-CT.

To evaluate the feasibility of synchrotron-based phase-contrast (PC) μCT for visualization of the gaps and differentiation between the gaps, restorative, and endodontic materials at the tooth-restoration interface. Standardized access cavities were prepared in human maxillary molars and subjected to materials, simulating endodontic treatment: (1) saline irrigation; (2) NaOCl and 17% EDTA irrigation; (3) same as group 2, followed by application of Ca(OH)2; and (4) same as group 2, followed by application of root canal sealer. The access cavities were cleaned and restored using an etch-and-rinse adhesive and a composite material in multilayering technique. The samples were thermocycled (1000cycles, 5-55°C). Synchrotron-based μCT imaging was performed obtaining absorption and PC μCT images before and after the immersion of the samples into 50% AgNO3. PC μCT images were compared to absorption μCT and conventional optical microscopy images. PC μCT of unstained samples enabled the best visualization of gaps and differentiation of restorative and endodontic materials, contaminating the cavity surface. PC μCT revealed that AgNO3 staining leads to an overestimation of gap size due to anterograde and retrograde AgNO3 infiltration into dentinal tubules and underestimation of large gaps due to lack of AgNO3 penetration. Synchrotron PC μCT imaging enables better visualization of gap and differentiation of materials at the tooth-restoration interface. μCT imaging with AgNO3 staining has shown certain over- and underestimations. Future research should be aimed at incorporating PC μCT imaging of unstained samples for the validation of results obtained with other methods. Contamination of cavity walls with an endodontic sealer or Ca(OH)2 leads to increased gap formation at the tooth-restoration interface.

Comparison of Micro-Leakage around Temporary Restorative Materials Placed in Complex Endodontic Access Cavities: An In-Vitro Study.

To compare mean micro-leakage around 3 types of temporary restorative materials in-vitro, when placed adjacent to permanent restorations (amalgam) in complex endodontic access cavities. Randomized controlled trial. Dental Clinics, Dental Laboratory and Research Laboratory at The Aga Khan University Hospital, Karachi, from January to June 2014. After random allocation of 60 teeth into 3 experimental groups, each group had conventional class II cavities prepared and amalgam placed. After 14 days, endodontic access cavities were made in these teeth, followed by placement of Cavit, IRM and CLIP(depth of 4 mm each). After thermo-cycling and immersion in 0.5% methylene blue dye, the teeth were sectioned mesio-distally and observed under stereoscopic microscope (magnification x4) along 2 interfaces 'a' and 'b' (tooth-temporary restoration and temporary restoration-primary restoration), respectively. Depth of dye penetration was measured in millimeters. IRM was leakiest at interface 'a', cavit had highest dye penetration at interface 'b', while CLIP exhibited least micro-leakage at 'a' and 'b'. The mean dye penetration for Cavit was 0.80 ± 0.23 mm at 'a', and 2.24 ± 0.48 mm at 'b'. For IRM, it was 1.82 ± 0.09 mm at 'a', and 0.44 ± 0.13 mm at 'b'. For CLIP, the mean dye penetration was 0.43 ± 0.05 mm at 'a', and 0.32 ± 0.12 mm at 'b'. The difference in dye penetration observed between the 3 groups at both interfaces was statistically significant. In a complex access cavity made adjacent to a pre-existing amalgam restoration, CLIP exhibits the least micro-leakage, followed by IRM and Cavit.

Comparison of root canal length measurement methods in primary teeth

Objectives: The purpose of this study was to evaluate the accuracy of conventional radiography, intraoral digital radiovisiography and electronic apex locator in determining the working length of root canals in primary teeth (in-vivo) and to compare the results with scanning electron microscopy measurements (ex-vivo). Materials and Methods: This study was conducted on 50 primary molar teeth. Standard endodontic access cavity preparations were prepared and the actual length was calculated by calibrated investigators. Working lengths were determined by using conventional radiography, RVG and apex locator in a total of 116 root canals. After the extraction of the teeth, each canal length was determined by using SEM. Data were analysed statistically by using Oneway Anova, Tukey HDS, Student t test and Bonferroni tests. Results: The mean root length measurements with conventional radiography were significantly higher than apex locator, RVG and SEM. The accuracy of apex locator and RVG were higher than conventional radiography in determining the working length in primary teeth. Conclusions: The electronic apex locators provide an acceptable level of accuracy in determining root canal length in primary teeth. Clinical Relevance: The purpose of this study was to evaluate the accuracy of conventional radiography, intraoral digital radiovisiography and electronic apex locator in determining the working length of root canals in primary teeth and,to compare the results with scanning electron microscopy measurements.

Evaluation of relationship between endodontic access cavity types and secondary mesiobuccal canal detection

BackgroundThe aim of this study was to evaluate the relationship between Endodontic Access Cavity (EAC) types with MB2 canal detection ratio in the upper first molars.MethodsA total of 60 roots of extracted human maxillary first molars were selected. All teeth were prepared with Point EAC (PEAC), Conservative EAC (CEAC) and Traditional EAC (TEAC) respectively. After each group were completed, extra canal was searched. Preoperative and postoperative tooth weigh was calculated using precise scale. McNemar’s chi-square test and a paired test significant difference were used for statistical analyses.ResultsThe EAC types statistically were changed of tooth tissue loss quantity (p = 0.000). MB2 detection rate of CEAC (%53,3) and TEAC (%60) are higher than statistically that of PEAC (%31.6) (p < 0.05). 8 teeth MB2 canal was detected only with the CBCT images.ConclusionsIn upper molars, CEAC seems reasonable in terms of detected the MB2 canal and removed hard tissue.

Sala de aula invertida para o ensino do conteúdo abertura coronária em Endodontia

O objetivo deste estudo foi avaliar a sala de aula invertida como estratégia de ensino-aprendizagem para o conteúdo abertura coronária. O material didático para estudo prévio individual pelos estudantes foi disponibilizado online por meio de um software/aplicativo para desktop e dispositivos móveis contendo textos, imagens e vídeos demonstrativos. Nas aulas presenciais, o estudo prévio foi avaliado por um teste individual e em grupos houve discussão das respostas individuais monitorada pelo professor. Em seguida, foi apresentado um caso-problema, acompanhado de questões a serem resolvidas. Houve discussão das respostas até o entendimento e solução do problema apresentado. Vídeos com a sequência dos procedimentos para abertura coronária de elementos dentários simulados foram projetados antes e durante a execução da prática laboratorial. Por meio das respostas dos questionários de expectativa e de avaliação do método, 92,8% concordaram ser um método adequado para o aprendizado do tema proposto, apesar da maioria (64,2%) reconhecer que teriam dificuldades para o domínio do conteúdo. Após a atividade laboratorial, 100% dos estudantes estavam satisfeitos e confirmaram que o método contribuiu para o seu aprendizado. Além disso, 92,8% concordaram que a estratégia de ensino superou as expectativas e que estavam motivados para outras experiências. Os dados da autoavaliação de aquisição de competências pré e pós sala de aula invertida comprovaram que houve aprendizado significativo pelos estudantes e todos foram considerados habilitados baseados nos dados após a observação das habilidades pelo professor. Concluiu-se que a estratégia da sala de aula invertida foi adequada para o estudo do conteúdo abertura coronária.

The Effects of Endodontic Access Cavity Preparation Design on the Fracture Strength of Endodontically Treated Teeth: Traditional Versus Conservative Preparation

IntroductionThe aim of this study was to compare the fracture strengths of mandibular molar teeth prepared using traditional endodontic cavity (TEC) and conservative endodontic cavity (CEC) methods and restored using SDR (Dentsply Caulk, Milford, DE) and EverX Posterior (GC Dental, Tokyo, Japan) base composite materials. MethodsA hundred mandibular first molar teeth were randomly divided into 5 groups. In group 1 (the control group), samples were kept intact. In group 2, TECs were prepared, and the samples were restored with EverX Posterior and composite resin. In group 3, CECs were prepared, and the samples were restored with EverX Posterior and composite resin. In group 4, TECs were prepared, and the samples were restored with SDR and composite resin. In group 5, CECs were prepared, and the samples were restored with SDR and composite resin. This load was applied on the samples at 1-mm/min speed using a 6-mm round-head tip until fracture. The forces resulting in fracture were recorded in newton units. The data were analyzed using Kruskal-Wallis and Pearson correlation tests at a 5% significance level. ResultsThe fracture strengths of the samples in the control group were significantly higher than the experimental groups (P < .05). There was no statistically significant difference in the endodontic access cavities prepared used the TEC and CEC methods and restored using the same composite base material (P > .05). ConclusionsCEC preparation did not increase the fracture strength of teeth with class II cavities compared with TEC preparation. The fracture strength of teeth restored with the SDR bulk-fill composite was higher than that of teeth restored with EverX Posterior.

Stress distribution in a tooth treated through minimally invasive access compared to one treated through traditional access: A finite element analysis study.

Introduction:The purpose of this study was to compare the stress distributions in the teeth treated through minimally invasive access (MIA) designs to those of the teeth treated through traditional straight-line access and their relationship to the final restoration using three-dimensional finite element analysis (FEA).Materials and Methods:Four FEA models of an extracted mandibular first molar were constructed. An intact model served as the control, whereas the other three were prepared with either an MIA or traditional straight-line access. Simulated composite access fillings with or without a simulated gold crown were applied to the models, followed by application of an occlusal load of 100 N. Von Mises stresses in the teeth were then calculated and analyzed.Results:Stress values within the dentin for baseline, MIA with composite filling, MIA with composite filling and crown, and traditional access with composite filling and crown were 10.14 MPa, 6.98 MPa, 11.79 MPa, and 16.81 MPa, respectively. Higher stress values indicate that the tooth is more prone to fracture.Conclusions:A traditional endodontic access cavity may render a tooth more susceptible to fracture compared with an MIA design.

Does the Orifice-directed Dentin Conservation Access Design Debride Pulp Chamber and Mesial Root Canal Systems of Mandibular Molars Similar to a Traditional Access Design?

IntroductionDespite the increasing reports on mechanical aspects of contracted endodontic access cavities (CECs), we believe that the biological aspects (debridement) have not been adequately investigated. This study examined if 1 type of CEC (orifice-directed dentin conservation [DDC] access) was able to debride the pulp chamber, root canals, and isthmus of mesial roots of mandibular molars similar to a traditional endodontic access cavity (TEC). MethodsMandibular molars (N = 32) were selected and divided randomly into 2 experimental groups (n = 12) after micro–computed tomographic scanning (group 1: TEC and group 2: DDC) and histologic controls (n = 8). After instrumentation to a size 30/0.06 taper using 3% sodium hypochlorite as irrigant, specimens were processed for histologic evaluation, and the remaining pulp tissue (RPT) was measured from the pulp chamber, root canal, and isthmus at all root thirds. Data were analyzed using 1-way analysis of variance, Kruskal-Wallis, and appropriate post hoc tests (P = .05). ResultsThe RPT in the pulp chamber was significantly higher in DDC compared with TEC (P < .05). Comparing the root thirds in each group, there was no significant difference in the RPT within the root canals or the isthmus (P > .05). The RPT within the root canals and isthmus was not significantly different between the 2 access cavity designs at any root third (P > .05). ConclusionsDebridement of the pulp chamber was significantly compromised in DDC. The type of access cavity did not influence the amount of RPT in the root canals and isthmus.

Effect of access design on intracoronal bleaching of endodontically treated teeth: An ex vivo study.

To determine the effect of access design on intracoronal bleaching with 35% carbamide peroxide on discolored teeth. Forty-two intact maxillary central incisors were selected, sectioned and artificially stained using whole blood. Color measurements were performed with a spectrophotometer: before staining (T1), after staining (T2), at 7 (T3), and 14 (T4)days postbleaching. After T1, specimens were stratified and divided randomly into two groups according to access design (N=20): G1: contracted endodontic cavity (CEC) access performed with a #848-010M bur and G2: traditional endodontic cavity (TEC) access done with a #1157bur. Canals were obturated, a cervical barrier was placed and 35% carbamide peroxide was sealed in the chamber for 7days and replaced at 7days for an additional 7days. Data were collected based on CIELAB-CIE1976 (L* a* b* ) system. Repeated measures SNK anova was used to evaluate the effects of access design and time on color change (ΔE* ) and luminosity (L* ) (α<0.05). For CEC, L* was significantly different at all times points (P<.05). For TEC, L* values were significantly different at all time points (P<.05) except for T0 and T4, which were similar (P>.05). There was no statistical difference for ΔE* between CEC and TEC designs at any time point (P>.05). In general, teeth accessed with CEC or TEC designs showed statistically similar bleaching when using 35% carbamide peroxide. However, lightness values were only reestablished with bleaching through a TEC access design. Despite the current trend to conserve tooth structure when performing endodontic access cavities, the use of conservative access designs for bleaching discolored maxillary central incisors affected the acceptability threshold when compared with a traditional access design. These smaller accesses might not be an alternative treatment option when internal bleaching in the esthetic zone is anticipated.

A comparative clinical study to evaluate the effectof premedication with Ibuprofen, Tramadol and combination of Ibuprofen and Acetaminophen on success of Inferior Alveolar Nerve Block in patients with Asymptomatic Irreversible Pulpitis.

Introduction: Aim of this study was to evaluate the effective of premedication and to determine the difference between non steroidal anti- inflammatory drugs and centrally acting opioids like tramadol on success rate of inferior alveolar nerve block in patients with asymptomatic irreversible pulpitis.Methods: This double blind clinical study was conducted on 60 patients with asymptomatic irreversible pulpitis in first or second mandibular molar with normal periapical radiographic findings. Three medications i.e., ibuprofen (600mg), tramadol (50 mg) and combination of ibuprofen (400 mg) + acetaminophen (325) were compared and lactose powder capsules were taken as placebo. All patients received IANB and teeth were examined with a cold pulp test using endofrost. Then, endodontic access cavity preparation was initiated. In case of pain during treatment, patients were asked to rate their pain on the visual analog scale.Results: The tramadol group showed significantly higher success rates but ibuprofen and combination of ibuprofen and acetaminophen groups were not significant with placebo (p&gt;05). No Significant differences were there regarding sex of the patients.Conclusion: Premedication with tramadol increased the success rate of IANB.Bangladesh Journal of Medical Science Vol.16(3) 2017 p.370-374

Assessment of the accuracy of a fifth generation apex locator (in vitro study)

Background: The use of electronic apex locators for working length determination eliminates many of the problems associated with the radiographic measurements (interference of anatomical structures, errors in projection such as elongation or shortening, and lack of three-dimensional representation). Its most important advantage over radiography is that it measures the length of the root canal to the apical constriction, not to the radiographic apex. The aim of this study was to assess the accuracy of a new fifth generation apex locator (Joypex 5) in recording the apical constriction and comparing it with a third generation apex locator (Root ZX) in vitro. Materials and method: Twenty four single-rooted sound human premolars, extracted for the purpose of orthodontic treatment and with fully-formed roots, were used in this study. Endodontic access cavity was prepared in each tooth and canal patency up to the apical foramen was checked with a #15 stainless steel K-file. No root canal preparation was performed. Root canal length measurement was done directly and electronically using two apex locators (Joypex 5 and Root ZX). Direct measurement of the root canal length was done by introducing a #15 K-file inside the root canal until its tip was just visible at the apical foramen, then removed from the root canal and its length was measured (in mm) and subtracted by 0.5 mm. For electronic measurement, the teeth were fixed in a sponge soaked in saline and the root canals were also filled with saline. The lip electrode was attached to the sponge and the apex locators were used according to the manufacturers' instructions. The file holder was clipped to the metal shaft of a #15 K-file and the file was then inserted inside the root canal and advanced until the display reading on the LCD of the apex locator was 0.5. The file was then removed from the root canal and its length was measured (in mm). The differences between the readings of each apex locator and the actual length of each canal were computed, and the results were analyzed statistically by paired t-test using SPSS Version 13. Results: The results of this study showed that the Joypex 5 apex locator showed a lower mean difference than the Root ZX apex locator as compared with the actual length, which was statistically significant (p<0.05). Concerning the accuracy of the two apex locators, Joypex 5 apex locator recorded the apical constriction exactly in 67%, while the Root ZX apex locator in only 25%. Within ±0.5 mm from the actual length, the accuracy of the Joypex 5 and the Root ZX were 83% and 67%, respectively. Within ±1 mm from the actual length, the accuracy of the Joypex 5 and the Root ZX were 100% and 96%, respectively. Conclusion: The Joypex 5 apex locator which is a fifth generation apex locator was more accurate in recording the apical constriction as compared with the Root ZX apex locator which is a third generation apex locator.

The effect of cusp capping with composite resin on fracture resistance of premolars with prepared endodontic access cavities: An in vitro study

Introduction: The purpose of this study was to evaluate the effect of remaining dentinal wall thickness and the effect of remaining cusp height of endodontically treated premolars when restored with composite resin. Materials and Methods: Ninety premolars were divided into 4 test groups (n = 20) and 2 control groups (n = 5). In all groups, except the negative control group (sound teeth), standardized endodontic access cavities were prepared, pulp extirpated, mesioocclusodistal (MOD) cavities prepared and access sealed with Light Cure Glass Ionomer Cement (LC GIC). Test groups were divided as:- Cusp reduction for Groups I and II- 2.5 mm and for Groups III and IV- 1.5 mm. Dentinal wall thickness for Groups I and III- 1-1.5 mm and Groups II and IV- 2-3 mm. The groups were further subdivided into Subgroup A, restored with P60 and Subgroup B, restored with Herculite Precis. Positive control- only access cavity with no cusp reduction and restoration. Fracture resistance was assessed using Universal Testing Machine (UTM). Results: Highest fracture resistance was demonstrated by Group VI and least by Group V. Groups VI, II and I, showed statistically insignificant difference for both the composites (P > 0.05). Groups III and IV showed statistically significant difference only for Subgroup B. Conclusion: When the cusp reduction was 2.5 mm, dentinal wall thickness had no effect on the fracture resistance, for both the composites. When the cusp reduction was 1.5 mm and the remaining dentinal thickness was 1-1.5 mm, Herculite Precis showed inferior results to P60.

Evaluation of conventional, protaper hand and protaper rotary instrumentation system for apical extrusion of debris, irrigants and bacteria- An in vitro randomized trial

BackgroundEndodontic instrumentation carries the risk of over extrusion of debris and bacteria. The technique used and the type of instrumentation influences this risk.AimThe purpose of this study was to evaluate and compare the K-file, ProTaper hand and ProTaper rotary instrumentation systems for the amount of apically extruded debris, irrigant solution and intracanal bacteria.DesignExperimental single blinded randomized type of in vitro study with sample of 30 single rooted teeth. Endodontic access cavities were prepared and the root canals were filled with the suspension of E. faecalis. Myers and Montogomery Model was used to collect apically extruded debris and irrigant. Canals were prepared using K files, Hand protapers and Protaper rotary files.Statistical analysisNon Parametric test like Kruskal-Wallis and Mann-Whitney U test were applied to determine the significant differences among the group.ResultsTests revealed statistically significant difference between the amount of debris and number of bacteria extruded by the ProTaper hand and the K-files. No statistically significant difference was observed between the amounts of irrigant extruded by the ProTaper hand and the K-file system. Statistically significant differences were observed between the amounts of bacteria and irrigant extruded by the ProTaper rotary and the Protaper hand. No statistically significant difference was observed between the amounts of debris extruded by the ProTaper hand and the K-file system.ConclusionsAmount of apical extrusion of irrigant solution, bacteria and debris are significantly greater with K File instruments and least with Protaper rotary instruments. Key words:Protaper, rotary, periapical extrusion.

Determination of root canal configuration and the prevalence of “C-shaped” canals in mandibular second molar in central and South Gujarat population: An in vitro study

Aims: The aim of the present study was to determine the canal configuration and the prevalence of “C-shaped” canals in mandibular second molar in Central and South Gujarat population. Materials and Methods: A total of 122 mandibular second molar teeth were collected and stored in 10% formalin. Identification of these teeth as mandibular second molar was confirmed by two independent observers. An endodontic access cavity was then prepared in each tooth. Then, they were injected with India ink and demineralized, they were made clear and transparent with methyl salicylate. Then, anatomy of their canals was studied. Results: Out of 122 mandibular second molars, prevalence of “C-shaped” canals was 10.65% (13 teeth). These configurations were seen mostly in single-rooted mandibular second molars. Out of five categories of “C-shape,” predominantly found category was (C1) – 46.15%. Conclusion: Hard tissue of mandibular second molar contains dental pulp which can take a variety of configurations and shapes. The great differences reported among studies with regards to anatomy of the mandibular second molars and prevalence of “C-shaped” canals may be attributable to study methods and racial differences.

Apical Extrusion of Intracanal Bacteria with Single File and Multifile Rotary Instrumentation Systems.

Aims and Objectives:Instrumentation techniques may cause extrusion of microorganisms and their products into the periapical region resulting inflammation and treatment failure. The aim of this ex vivo study was comparing the apical bacterial extrusion in canals prepared with single file versus multiple file rotary systems.Materials and Methods:Ninety-two human single-rooted mandibular first premolars were used. Endodontic access cavities were prepared, and root canals were contaminated with an Enterococcus faecalis (E. faecalis) suspension. The samples were incubated at 37°C for 30 days; the contaminated teeth were divided into four groups of 20 specimens each (1: Reciproc, 2: Mtwo, 3: Neoniti A1, 4: Safesider). Six teeth were not infected and each were prepared with one of the above instruments were considered as negative and six teeth which had been previously infected, were used as positive control groups. Extruded bacteria from the apical foramen during instrumentation were collected into vials containing 0.9% NaCl. The microbial samples were taken from the vials and incubated in brain heart agar medium for 24 h. The resulting bacterial titer, in colony-forming units per mL, was determined. The data entered into SPSS 18 software and were analyzed by Kruskal–Wallis and Mann–Whitney U-tests at 0.05 significance level.Results:Mtwo multifile system showed significantly less bacterial extrusion than Safesider (P = 0.015) and Neoniti A1 (P = 0.042) but did not show significant difference with Reciproc system (P = 0.25).Conclusions:All instrumentation systems extruded bacteria beyond the apical foramen. However, this study showed that Mtwo multifile rotary system extruded fewer bacteria.