Endodontic Space Research Articles

An in vitro evaluation of the degree of pulp tissue dissolution through different root canal irrigation protocols.

Aim:The aim of this study is to evaluate in vitro, using artificial lateral canals, the rate of dissolution of the pulp tissue through different protocols of canal irrigation.Materials and Methods:One hundred artificial canals provided with lateral canals have been used. Each lateral canal was filled with pulp tissue and calibrated to 0.002 mg. All canals were irrigated using five different protocols. Five groups have been used for the experiment: Group A, distilled water (control); Group B, preheated NaOCl; Group C, NaOCl heated inside the canal; Group D, NaOCl ultrasonically activated; and Group E, NaOCl heated inside the canal with ultrasonic activation. All samples were weighed through professional microbalance in three different phases: before insertion of the pulp tissue into the lateral canal, after insertion of the pulp tissue and, finally, after different protocols of irrigation. A statistical analysis with Kruskal–Wallis test and Mann–Whitney test was performed.Results:The partial dissolution of the pulp tissue inside the artificial lateral canal occurs only using the protocol with NaOCl heated inside the canal with ultrasonic activation. Other irrigation protocols are not able to dissolve the pulp tissue.Discussion and Conclusions:The main objective of endodontic therapy is the removal of damaged tissues and bacteria. Modern literature highlights that it is impossible to remove all the pulp tissues and bacteria from the whole endodontic space. Hence, to achieve excellence and get positive results in the short and long term, it is necessary to use techniques and technologies that may increase the degree of root canal detersion.

The Importance of the Magnification Use for the Additional Root Canals Localization at the Second Maxillary Molars

The aim of this study is to highlight the morphology of the second maxillary molars root canals and to draw a comparison between the data obtained with and without magnifying means. The study covered a total of 31 extracted human second maxillary molars. After being examined by a thorough physical exam and an X-ray examination, teeth were trepanned in the place of election. Thereby the access cavity was performed using: a) for the stage of pulp chamber ceiling penetration, a globular diamond bur for the turbine, b) for the stage of broadening access cavity, a cylindrical bur inactive in the head for the opposite-angle piece and c ) a Batt bur for the flaring and finishing stage.Afterwards, the sighting of the main root canals was performed using the endodontic probe or Miller file. Examination and sighting of the additional canals was made under magnification using the dental microscope. The molars with three canals had the highest prevalence of endodontic morphology of two upper molars (90.32%). But there were special cases with two channels morphology (6.45%) and four channels morphology (3.22%). After examining the endodontic space under the microscope, there have been identified and secondary canals, approximately 32.25% of molars examined presenting one or more secondary canals. The anatomy of the most frequent upper second molar was three roots with three root canals; the most common variation in morphology is the presence of an mesiobuccal additional canal (MB2). However, we can encounter an unusual number of canals. The importance of magnification, of the dental microscope in our study cannot be ignored because using only the latter we could highlight the real endodontic morphology of the two upper molars extracted examined, finding additional canals in 32.25% of the molars undergoing examination.

Current challenges in human tooth revitalization.

Tooth vitality and health are related to the presence of a living connective tissue, the dental pulp (DP), in the center of the dental organ. The DP contains the tooth immune defence system that is activated against invading oral cariogenic bacteria during the caries process and the tissue repair/regeneration machinery involved following microorganisms' eradication. However, penetration of oral bacteria into the DP often leads to complete tissue destruction and colonization of the endodontic space by microorganisms. Classical endodontic therapies consist of disinfecting then sealing the endodontic space with a gutta percha-based material. However, re-infections of the endodontic space by oral bacteria can occur, owing to the lack of tightness of the material. Recent findings suggest that regenerating a fully functional pulp tissue may be an ideal therapeutic solution to maintain a tooth defence system that will detect and help manage future injuries. The objective of this paper was to explain the different revascularization and regeneration strategies that have been proposed to reconstitute a living DP tissue and to discuss the main challenges that have to be resolved to improve these therapeutic strategies.

Complex Apical Anatomy Revealed Following Endodontic Treatment of a Maxillary Molar Using the GentleWave System: A Case Report

Introduction: Primary root canal treatment success depends on a number of variables, including debridement and disinfection of the root canal system to remove all bacteria and diseased pulpal and dentinal tissues. Complex root canal anatomy, such as concealed isthmuses, apical deltas and lateral canals, hinder this objective, making instrumentation of these regions nearly impossible. Recent advancements within the endodontic space have focused on improved cleaning and disinfection techniques that will enhance cleaning and debridement, even in difficult to navigate anatomy within the apical third. Background: This case study explores the effectiveness of the GentleWave® Procedure in treating a maxillary second molar diagnosed with irreversible pulpitis and symptomatic apical periodontitis that also featured complex apical root canal anatomy that was undetected until obturation was completed. Methods: A minimally invasive endodontic protocol was utilized to maximize preservation of tooth structure. The tooth was conservatively accessed followed by minimal instrumentation to a size 25/04 for creation of a fluid path and to facilitate future placement of root canal obturation material. Multisonic Ultracleaning™ and debridement were accomplished with the GentleWave Procedure. After obturation with gutta-percha and sealer, a final radiograph revealed a clinically significant obturation with previously unseen lateral canals and an isthmus within the apical third. Results: The previously diagnosed symptomatic apical periodontitis had fully resolved by the three-week followup visit. This case report demonstrates a viable minimally invasive endodontic treatment for uncovering root canal systems with complex apical anatomy utilizing the GentleWave Procedure.

Shaping of the Root Canal System: A Multistep Technique

The aim of this scientific work is to illustrate the technique of shaping the root canal system using the multistep technique. Over time, various endodontic instrumentation techniques have been put forward, from the "step-back" technique (apical-coronal) to the "crown-down" technique (coronal-apical), the "double-flared" technique, and the most recent "single-length" technique. The multistep technique involves six steps, one of the main objectives of these being the safety of the use of mechanical instruments with a reduction in the risk that they fracture. This technique ("mixed") provides for the use of both manual instruments in stainless steel and mechanical instruments in nickel titanium (Ni-Ti). The multistep technique is based on a standardized, flexible, and clinical protocol, which can provide for a reduction in the number of endodontic passages and instruments used and, therefore, a simplification of the operating procedure depending on both the difficulty of the root canals and the competence of the operator. This technique is a technique for shaping the endodontic space that allows the set objectives of endodontic therapy to be reached in a predictable way with a reduced risk of iatrogenic complications.

Root Canal Irrigation: Chemical Agents and Plant Extracts Against Enterococcus faecalis.

Background:There are various microorganisms related to intra and extra-radicular infections and many of these are involved in persistent infections. Bacterial elimination from the root canal is achieved by means of the mechanical action of instruments and irrigation as well as the antibacterial effects of the irrigating solutions. Enterococcus faecalis can frequently be isolated from root canals in cases of failed root canal treatments. Antimicrobial agents have often been developed and optimized for their activity against endodontic bacteria. An ideal root canal irrigant should be biocompatible, because of its close contact with the periodontal tissues during endodontic treatment. Sodium hypoclorite (NaOCl) is one of the most widely recommended and used endodontic irrigants but it is highly toxic to periapical tissues.Objectives:To analyze the literature on the chemotherapeutic agent and plant extracts studied as root canal irrigants. In particularly, the study is focused on their effect on Enterococcus faecalis.Method:Literature search was performed electronically in PubMed (PubMed Central, MEDLINE) for articles published in English from 1982 to April 2015. The searched keywords were “endodontic irrigants” and “Enterococcus faecalis” and “essential oil” and “plant extracts”.Results:Many of the studied chemotherapeutic agents and plant extracts have shown promising results in vitro.Conclusion:Some of the considered phytotherapic substances, could be a potential alternative to NaOCl for the biomechanical treatment of the endodontic space.

Configuraţia canalelor laterale şi accesorii din zonele de furcaţie în cazul molarilor superiori – ipoteze legate de procesul de sigilare al acestor

The difficulty issuing assumptions sealing lateral canals is closely linked to the unpredictability constituting where the elements are placed in the lateral canal content (connective tissue, necrotic tissue, microbial germs, which can interfere with the sealant, influencing the quality of sealing). It is known that these lateral channels can not benefit from debridement and instrumentation, implying persistent organic content, which interferes with the sealing. The aim of this study is to highlight the lateral canals and accessory furcation on extracted teeth using dye impregnation methodology that is commonly used to identify internal anatomical configuration of the endodontic space. The study also aims to identify the pattern of lateral canals in addition to the establishment of theoretical models about the thereof process of sealing. Thus, imagines sealant flow patterns through lateral channels by applying Bernoulli’s principle and Darcy’s law.

New Technologies to Improve Root Canal Disinfection.

Effective irrigant delivery and agitation are prerequisites to promote root canal disinfection and debris removal and improve successful endodontic treatment. This paper presents an overview of the currently available technologies to improve the cleaning of the endodontic space and their debridement efficacy. A PubMed electronic search was conducted with appropriate key words to identify the relevant literature on this topic. After retrieving the full-text articles, all the articles were reviewed and the most appropriate were included in this review. Several different systems of mechanical activation of irrigants to improve endodontic disinfection were analysed: manual agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems activated by low-speed hand-pieces or by sonic or subsonic energy, use of ultrasonic or laser energy to mechanically activate the irrigants and apical negative pressure irrigation systems. Furthermore, this review aims to describe systems designed to improve the intracanal bacterial decontamination by a specific chemical action, such as ozone, direct laser action or light-activated disinfection. The ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard to which all other systems of mechanical agitation analyzed in this article were compared. From this overview, it is evident that the use of different irrigation systems can provide several advantages in the clinical endodontic outcome and that integration of new technologies, coupled with enhanced techniques and materials, may help everyday clinical practice.

Nuove tecnologie per il miglioramento della disinfezione canalare

ObjectivesThe aim of this study is to share with the reader the latest available technologies to improve the cleaning and debridement of the endodontic space and to give some hints to consider when integrating such new technologies into everyday clinical practice. Materials and methodsDifferent systems of mechanical activation of irrigants aimed at improving endodontic disinfection through a more effective removal of intracanal contents were analysed: manual mechanical agitation with gutta-percha cones, endodontic instruments or special brushes, vibrating systems, systems activated by low-speed handpieces or by sonic or subsonic energy, up to the use of laser to mechanically activate the irrigants and of apical negative pressure irrigation systems. Furthermore, systems aiming at improving the endocanalar bacterial decontamination through the use of chemicals were described, such as menozone, direct laser action, or light activated disinfection techniques Results and conclusionsThe ultrasonic activation of root canal irrigants and of sodium hypochlorite in particular still remains the gold standard by which all other systems of mechanical agitation analyzed in this dossier were judged.

STUDIUL INFILTRAŢIEI APICALE A OBTURAŢIILOR DE CANAL CU GUTAPERCĂ VERSUS RESILON

The purpose of the study is to assess the apical sealing ability of the endodontic space using two types of canal filling techniques: vertical compaction of warm gutta-percha and AhPlus sealer compared with Resilon and RealSeal SE. Two sets of extracted human teeth were prepared with rotary instruments, each 20 teeth being obturated by the two techniques: the classical and the adhesive root canal filling. The apical leakage of the root canal filling made with Resilon and RealSeal SE was higher than the one with gutta-percha and AhPlus. The difference was statistically significant.

Assessment of root canal enlargement using Mtwo and BioRace rotary files.

Objective. To evaluate root canal enlargement following mechanical shaping using 2 nickel titanium rotary systems. Material and Methods. Forty single-rooted teeth were immersed in resin and sectioned perpendicular to the long axis at 4, 8, and 12 mm from the apex. Digital capture of sections was performed before and after canal instrumentation using Mtwo and BioRace instruments. The area increase of endodontic space was calculated by subtraction. Results. The use of both instruments has allowed the removal of great amounts of dentin from the canal walls, even when the endodontic morphology is characterized by awkwardness to reach recesses. Conclusions. Both procedures seem to be valid and no differences were found between Mtwo and BioRaCe considering the amount of dentin removed at different distances from the apex.

IN VIVO ANALYSIS OF SOME KEY CHARACTERISTICS OF THE APICAL ZONE IN TEETH WITH CHRONIC APICAL PERIODONTITIS

Introduction: The pathogenesis of internal and external resorptive processes in the dental tissues and those of the periapical zone is not fully understood, but the main purpose, either in teeth with internal resorption or in teeth with periapical lesions, is decontamination of the endodontic space and subsequent three-dimensional obturation in order to isolate periapical and oral tissues and prevent reinfection. Purpose: The aim of this article is to analyze in vivo some key characteristics of the apical zone in teeth with chronic apical periodontitis. Material and Methods: To facilitate the clinical protocol after the radiographic analysis and assessment of patency, the working lengths of 153 root canals (n = 153) in 106 teeth were determined. The clinical widths of the apical narrowing were measured by using the last instrument (ISO 0.02 tapered file), which can move freely through the apical narrowing after electrometric determination of the working length (Raypex 5 /VDW, Germany/). Results and Discussion: Determination of working width and working length is important for realizing the first stage of decontamination – maximum instrumentation of the endodontic space and choice of a clinical protocol. The classification of root canals in a particular group according to the relative patency or lysed apical opening is important for the selection of obturation technique, which is essential for reducing the microleakage in the zone. Conclusion: Since the target of this work were teeth with CAP, in the majority of the cases with clinical findings of root canals with preexisting filling, radicular pins, obliteration, separated canal instruments, perforations at different levels, via falsa or thresholds, the access to the apical zone was not subjected to a closely observed instrumental clinical protocol. In the treatment of each case, however, the clinical principles of modern endodontic treatment were closely observed.

Accuracy of an Electronic Apex Locator in the Retreatment of Teeth Obturated with Plastic or Cross-linked Gutta-percha Carrier-based Materials: An Ex Vivo Study

IntroductionThis ex vivo study evaluated the accuracy of the Root ZX electronic apex locator (EAL) (J Morita Corp, Kyoto, Japan) in determining the working length during retreatment of canals sealed with 2 different carrier-based obturating materials (ProTaper Obturator [Dentsply Maillefer, Ballaigues, Switzerland] and GuttaCore [Dentsply Maillefer]) and also evaluated whether they influenced its accuracy differently. MethodsFifty extracted single-rooted human teeth with sound apices were selected for the study. We measured canals with the direct visual technique using a #10 K-file and shaped them with ProTaper Universal instruments (Dentsply Maillefer) up to this predetermined length. After instrumentation, we determined the canal length again using the visual technique (direct length [DL]). This value was considered the “reference point.” Specimens were then placed in a tooth holder (Pro-Train; Simit Dental, Mantova, Italy), and the canal length was electronically measured (electronic length 1 [EL1]). Specimens were then obturated with ProTaper Obturators (group 1, n = 25) and GuttaCore (group 2, n = 25). Seven days later, a new electronic length was determined (electronic length 2 [EL2]) during retreatment procedures in the presence of the obturating material. EL1 and EL2 values were compared with DL using the Bland and Altman method. The different influences of the tested materials on the accuracy of the EAL were calculated with repeated measures analysis of variance. ResultsBoth EL1 and EL2 values provided a statistically significant overestimation of the actual canal length (DL [P < .05]), with the EL2 values higher from DL. The 2 different materials did not influence the accuracy of the EAL differently (P = .486). ConclusionsThe measurements obtained with the EAL tested during orthograde retreatments can lead clinicians to overinstrumentation and consequent overfilling of the endodontic space.

PERIAPICAL RESORPTIVE PROCESSES IN CHRONIC APICAL PERIODONTITIS: AN OVERVIEW AND DISCUSSION OF THE LITERATURE

Introduction: Root resorption is a biological phenomenon, characterized by processes of cement and/or dentine depletion, resulting from the physiological or pathological activity of resorptive cells. Purpose: The aim of this article is to review of the literature on the peculiarities of the periapical resorptive processes. Conclusion: The absence of a physiological narrowing is challenging to the achievement of satisfactory early and late therapeutic results. It makes probable either the overpressing of necrotic, infected material when preparing the endodontic space or the overpressing of the sealer when sealing the root canal.

Repair of perforation with Mineral trioxide aggregate (MTA)

Root perforations may occur due to pathological processes or treatment consequences. Such perforations are severe complications and are associated with dramatically compromised endodontic treatment outcomes, especially when bacterial infection is allowed to establish and if the seal between the endodontic space and periradicular tissue is not provided. A new known material, mineral trioxide aggregate (MTA) promotes a favorable environment for regeneration and has been successfully used for various endodontic surgeries, apexification and perforation procedures. This case report describes the management of perforation which occurred in the critical region of tooth. Keywords: MTA, Perforation, Anterior tooth

Root canal obturation: experimental study on the thermafil system related to different irrigation protocols

The aim of this study was to stress the ability of a specific obturation technique (thermafil technique) to seal root canal system in presence or absence of smear layer. Sixteen monoradicular teeth, extracted for periodontal reasons, were collected for this study. All specimens were prepared with nickel-titanium rotary files, and then divided into two groups: for each group was applied a different kind of irrigation method, verifying the effectiveness in removing the smear layer, thus rendering the dentinal tubules more permeable for penetration of softened gutta-percha. Thermafil system was used to fill the root canals, and then all the specimens were observed under scanning electron microscope (SEM). The results showed that the Group which followed irrigation only with sodium hypochlorite exhibited significantly less gutta-percha tags when compared to the second Group, which was irrigated with sodium hypochlorite and EDTA. The thermafil systems have a very good quality of compression and fluency that permit to gain a good seal of endodontic space; furthermore it allows the penetration of gutta-percha with the formation of numerous of gutta-percha tags inside the dentinal tubules above all when smear layer is reduced or eliminated.

The endodontic line: A clinical approach

Summary The shaping using instruments in nickel titanium and the obturation made with thermoplastic materials represent the current trends for what concerns shaping and canal filling. To this protocol is added the use of high title NaOCl and EDTA solution. Endodontic treatments are currently based on changes in the shape and contents of what is known as the endodontic space: it is difficult to distinguish the point, or, better, the so called passage plan between “in” and “out”. This article is focused on the management of the endodontic line. Endodontic anatomy is complex and only rarely formed by one canal with a unique foramen. However, our current treatments are based on techniques in which the shaping is focused on a single port of exit. With these recent methods it is better to bring the wound at the end of the endodontic space by identifying this space using electronic apex locators. The authors believe that it is not convenient to let the repairing mechanisms occur inside the endodontic space.

Evaluation of root canal obturation using gas permeability method

Introduction. Prognosis of root canal treatment is highly dependent on the quality of endodontic space obturation. The main task of successful root canal treatment is to achieve adequate reparation processes in the apical periodontium. The aim of this study was to evaluate the quality of root canal obturation using the method of gas (argon) penetration through three different endodontic materials. Material and Methods. Thirty recently extracted human single-rooted teeth after root canal instrumentation were divided into three identical groups and obturated with three different endodontic materials: group I - GuttaFlow (RSA, Germany), group II - AH Plus (DeTray, Germany), group III - Acroseal (Septodont, France). The quality of root canal obturation was evaluated using the method of gas permeability. Results. The best results were obtained with GuttaFlow. The average penetration rate of argon was 186.7 seconds. Slightly higher gas porosity had AH Plus, 179.9 seconds, while the highest gas permeability was observed after the application of Acroseal, 178.5 seconds. However, there was no statistically significant difference in gas penetration among these endodontic materials (p&gt;0.05). Conclusion. All three endodontic materials showed gas permeability in a given time interval. The best quality of obturation was achieved with GuttaFlow, while the lowest quality was obtained with Acroseal.

Otturazione del sistema dei canali radicolari con guttaperca termoplasticizzata: principi, materiali e tecniche

Objectives As described and shown by Schilder, the success of the endodontic treatment depends on the ability of the operator to shape the main canal and to cleanse and fill the whole endodontic space three-dimensionally; since after shaping and cleaning it is very difficult, if not impossible, to reach the complete sterilization of the canal, the filling is still a conclusive phase for the success of the whole treatment. Today, the only technique that allows to get a reliable and predictable seal of all the “exit doors” of the canal is based on the use of warm gutta-percha vertically compacted. Materials and methods Thanks to technological evolution, currently a complete range of tools is available to the clinician, suitable to different variations of compaction of the thermoplastic gutta-percha. The article considers the technique of filling described by Schilder, analyzing its biological motivations and mechanics, deepening the knowledge of the physical features of gutta-percha and clinically describing in details the most feasible methods, such as the continuous wave of condensation, devoleped by Steve Buchanan, and the thermo-hydraulic condensation described by Joseph Nahmyas. Results and conclusions The vertical gutta-percha obturation technique is based on the assumption that the root canal system, once cleaned, can be effectively sealed in all its ramifications provided that we succeed in giving a correct “shape of resistance” to the main canal. Assimilating the guidelines outlined in this article and understanding the importance of an adequate three-dimensional filling of the root canal system in relation to the established biological principles of modern Endodontics will let us achieve consistently excellent root canal treatments and produce satisfactory results for both the clinician and the patient.

Adhesion to Intraradicular Dentin: A Review

Luting fiber posts to intraradicular dentin remains an unpredictable goal due to various clinical factors influencing the clinical procedure. Primarily differences can be found between bonding to coronal or to intraradicular dentin due to the different histological characteristics of the substrates, the high C-factor of the endodontic space, the presence of smear layer due to the post preparation technique, incompatibility between some adhesive systems and resin-based cements, and finally the limited access of the post space that may lead the clinician to different mistakes. Thus this article critically evaluates all aspects that may jeopardize the adhesion of luted fiber posts within the endodontic space, suggesting the use of standardized techniques that improve immediate adhesion and stabilize the adhesive interface over time. The review of the data currently available in peer-reviewed journals suggests that a strict following of a step-by-step clinical standardized technique allows the clinician to minimize bond failure and obtain a clinically reliable durable bond.