Ultrasonics in endodontics: a review of the literature

During the past few decades endodontic treatment has benefited from the development of new techniques and equipment, which have improved outcome and predictability. Important attributes such as the operating microscope and ultrasonics (US) have found indispensable applications in a number of dental procedures in periodontology, to a much lesser extent in restorative dentistry, while being very prominently used in endodontics. US in endodontics has enhanced the quality of treatment and represents an important adjunct in the treatment of difficult cases. Since its introduction, US has become increasingly more useful in applications such as gaining access to canal openings, cleaning and shaping, obturation of root canals, removal of intracanal materials and obstructions, and endodontic surgery. This comprehensive review of the literature aims at presenting the numerous uses of US in clinical endodontics and emphasizes the broad applications in a modern-day endodontic practice.     

The importance of microleakage in endodontics: conclusions for the endodontic practice

There is a difference between the clinically and even radiographically determined success for endodontic therapy. One of the main reasons for reduced success rate is the poor quality of root canal treatment namely the presence of microleakage. Shortcomings created during preparation, including canal transportation and canal deformities resulted in reduced healing rate of treated cases. Curvatures or irregular shape can hamper the proper cleaning of the whole root canal even by the latest generation of instruments available on the market. More recently published papers have emphasized the increasing role of usage of chemical agents to complete debridement of the root canal system. Some authors suggested to replace the root canal instrumentation with using special kind of chemical agents more frequently. Does the introduction of non instrumentation technique or another kind of idea for cleaning and shaping of the root canal system can significantly change the treatment outcome of the root canal fillings in the future?     

Methodologies for assessment of apical and coronal leakage of endodontic filling materials: a critical review

Apical leakage continues to be a topic of great interest, because in spite of the advances in Endodontics, clinical failures still occur. Most failures are probably attributed to the proliferation of bacteria that remain viable after chemical-mechanical preparation and cause periapical tissue irritation. Coronal leakage has aroused researchers' interest over the last few years, since canals may be re-contaminated after loss of coronal sealing or fracture of the remaining tooth. In this review, the various methodologies used for assessing root canal sealing capacity are critically analyzed, as they are not standardized, which makes it difficult to compare the results obtained when different methodologies are used, even though the same substrate is being assessed.     

Digital and advanced imaging in endodontics: a review

This review provides an overview of digital radiography as it exists, including advanced imaging such as computed tomography (CT), cone beam volumetric imaging, and micro-CT as relevant to the practice of endodontics. An evidence-based approach to adoption of different imaging technologies is included to assist the practitioner with the selection process of imaging modalities. Commonly used imaging terminology is introduced, as well as the advantages and disadvantages of image processing. New image reconstruction techniques have been introduced that provide information three-dimensionally to the clinician for routine endodontic and surgical treatment planning. The age of three-dimensional imaging and image processing is here. Limitations and advantages of newly introduced imaging modalities are discussed briefly.     

Clinical implications of the smear layer in endodontics: a review

It has been recognized for many years that root canal instrumentation produces a smear layer that covers the surfaces of prepared canal walls. This layer contains inorganic and organic substances such as fragments of odontoblastic processes and necrotic debris. There is a lack of agreement regarding the effect of the smear layer on the quality of instrumentation and obturation, but the smear layer itself may be infected and may protect the bacteria within the dentinal tubules. Various methods have been used to remove the smear layer. Conflicting results have been obtained from numerous in vitro studies regarding the significance of the presence or the removal of the smear layer.     

Histopathological and microbiological findings associated with retrograde peri-implantitis of extra-radicular endodontic origin: a systematic and critical review

The aim of this study was to systematically review the aetiology, in particular histopathological and microbiological factors, of retrograde peri-implantitis of endodontic origin. The review is registered in the PROSPERO database (CRD42017063898). An electronic search for publications was performed in two databases, from their inception up to October 2018. Subsequently a hand search of the reference lists was conducted. Articles in English and other languages using Latin characters were included. Two independent reviewers selected the studies, extracted and synthesized the data, and assessed the quality. The methodology of the included articles was evaluated using the relevant Joanna Briggs Institute tools. Six studies fulfilled the eligibility criteria and were included in the systematic review. Histopathological examination in the component studies reflected that the presentation of retrograde peri-implantitis involves cyst formation or chronic inflammation. Bacteria found in these lesions included Porphyromonas gingivalis, Corynebacterium, Streptococcus, and Klebsiella pneumoniae. Two studies were judged as having a low possibility of bias and four were judged as having a moderate possibility of bias. This review determined that endodontic complications associated with adjacent teeth, residual infection at the extraction site due to previous apical periodontitis, or refractory apical periodontitis might be considered likely aetiological factors, although the evidence is limited.     

Taurodontism: a review of the condition and endodontic treatment challenges

Taurodontism can be defined as a change in tooth shape caused by the failure of Hertwig's epithelial sheath diaphragm to invaginate at the proper horizontal level. An enlarged pulp chamber, apical displacement of the pulpal floor, and no constriction at the level of the cementoenamel junction are the characteristic features. Although permanent molar teeth are most commonly affected, this change can also be seen in both the permanent and deciduous dentition, unilaterally or bilaterally, and in any combination of teeth or quadrants. Whilst it appears most frequently as an isolated anomaly, its association with several syndromes and abnormalities has also been reported. The literature on taurodontism in the context of endodontics up to March 2007 was reviewed using PubMed, MEDLINE and Cumulative Index to Nursing & Allied Health Literature. Despite the clinical challenges in endodontic therapy, taurodontism has received little attention from clinicians. In performing root canal treatment on such teeth, one should appreciate the complexity of the root canal system, canal obliteration and configuration, and the potential for additional root canal systems. Careful exploration of the grooves between all orifices particularly with magnification, use of ultrasonic irrigation; and a modified filling technique are of particular use.     

牙周来源的牙周牙髓联合病变和牙周牙髓共存病变患牙牙周治疗时机的系统评价

目的 评估牙周来源的牙周牙髓联合病变以及真正联合病变（牙周病变和牙髓病变共存）患牙的牙周治疗时机,从而指导临床治疗。方法 在PubMed、EMbase、Cochrane、Web of Science、CNKI、CBM、万方数据库中搜索1980年至2017年3月间关于牙周牙髓联合病变治疗的相关文章,并对其进行分析。结果 最终纳入2篇随机对照研究、2篇前瞻性病例系列研究和8篇病例报告。所有研究病例均采用根管治疗和牙周非手术治疗或牙周手术治疗,且根管治疗是综合治疗的第一步;观察指标包括牙周探诊深度及附着丧失等。结论 对于牙周来源的牙周牙髓联合病变和真正的联合病变患牙,牙髓治疗和牙周非手术治疗间可能不需要观察期,但此结论还需大样本前瞻性随机对照临床研究来验证。     

Ledge formation: review of a great challenge in endodontics

Failure to grasp the rationale behind cleaning and shaping concepts can increase the occurrence of needless complications, such as ledges. A ledge is created when the working length can no longer be negotiated and the original pathway of the canal has been lost. Extension of the access cavity to provide unobstructed access to the root canals, precurving and not forcing instruments, using NiTi files, using passive step-back and balanced force techniques, and instrumenting the canal to its full length will all help to prevent ledge formation. Initial negotiation and bypassing the ledge can be achieved using a small file with a distinct curve at the tip, whereas a slight rotation motion of the file combined with a 'picking' motion can often help advance the instrument. A review of the literature and a discussion of the options for prevention, recognition and managing the ledge are presented.     

Ultrasonics in endodontic surgery: a review of the literature

Currently, although ultrasonics (US) is used in dentistry for therapeutic and diagnostic applications as well as for cleaning of instruments before sterilization, its main use is for scaling and root planing of teeth and in root canal therapy, both for orthograde and retrograde therapy. Both in conventional and surgical treatments, US in endodontics has enhanced quality of clinical procedures and represents an important adjunct in the treatment of difficult cases. More precisely it has become increasingly more useful in applications such as gaining access to canal openings, cleaning and shaping, obturation of root canals, removal of intracanal materials and obstructions, and endodontic surgery. This review of the literature aims at presenting the numerous advantages of US in surgical endodontics and emphasizes its application in a modern-day endodontic practice.     

Clinical applications of glass ionomers in endodontics: a review

Glass ionomer cements (GICs) are biocompatible and have capacities to release fluoride and to bond to dentine, and thus are appropriate for use in endodontics. This paper reviews the composition and properties of different GICs, including their biocompatibility and antibacterial activity, their applications as intraorifice barriers and root canal sealers, and their use in the repair of root perforations, root‐end fillings and temporary coronal restorations.     

Modern endodontic surgery concepts and practice: a review

Endodontic surgery has now evolved into endodontic microsurgery. By using state-of-the-art equipment, instruments and materials that match biological concepts with clinical practice, we believe that microsurgical approaches produce predictable outcomes in the healing of lesions of endodontic origin. In this review we attempted to provide the most current concepts, techniques, instruments and materials with the aim of demonstrating how far we have come. Our ultimate goal is to assertively teach the future generation of graduate students and also train our colleagues to incorporate these techniques and concepts into everyday practice.     

The flare-up phenomenon in endodontics: a clinical perspective and review

The acute endodontic cellulitis exacerbation, which can be potentially fatal, is a definitive entity in endodontic flare-ups. Aerobic microbes, particularly streptococci, are the predominant causative microbes isolated. There was a noticeable absence of obligate anaerobes. This is significant for the selection of an antibiotic for therapy. Treatment parameters were presented. An endodontic cellulitis exacerbation is most unlikely with obligate anaerobes. An endodontic flare-up perspective was attempted with some clinical parameters. The proponents of routine one-visit endodontic treatment with prophylactic drugs to prevent cellulitis exacerbations do not appear to offer any advantage to the more traditional approaches to endodontic treatment of the patient, which may be more beneficial.     

Relationship between dental occlusion and brain activity: A narrative review

ObjectivesOcclusal function stimulates different areas of the cerebral cortex. The purpose of this narrative review was to identify the relationship between occlusion and brain activity so as to provide theoretical support to enable future studies on the subject.Study selection, data, and sourcesRelevant case-control studies, clinical trials, and systematic reviews available in English were retrieved from the following databases: MEDLINE, PubMed, ScienceDirect, Wiley Online Library, and Biblioteca Virtual en Salud (BVS). Of the 53 articles obtained, 12 were included.ConclusionThe sensorimotor cortex is affected by changes in occlusion. It is speculated that occlusion could play an important role in the development of diseases, from anxiety and stress to Alzheimer’s disease and senile dementia. Further investigations into the interactions between occlusion and brain function are needed to elucidate the parts of the brain that are affected when occlusion is disturbed and to determine whether brain function is altered.Clinical significanceDentists must consider that alterations in the occlusal pattern during mastication can lead to changes in the activation of different brain regions related to memory, learning, anticipatory pain, and anxiety. This suggests that mastication maintains the integrity of certain brain areas and that it may be a key factor in the onset of neurodegenerative diseases.     

Regenerative endodontics: a review of current status and a call for action

Millions of teeth are saved each year by root canal therapy. Although current treatment modalities offer high levels of success for many conditions, an ideal form of therapy might consist of regenerative approaches in which diseased or necrotic pulp tissues are removed and replaced with healthy pulp tissue to revitalize teeth. Researchers are working toward this objective. Regenerative endodontics is the creation and delivery of tissues to replace diseased, missing, and traumatized pulp. This review provides an overview of regenerative endodontics and its goals, and describes possible techniques that will allow regenerative endodontics to become a reality. These potential approaches include root-canal revascularization, postnatal (adult) stem cell therapy, pulp implant, scaffold implant, three-dimensional cell printing, injectable scaffolds, and gene therapy. These regenerative endodontic techniques will possibly involve some combination of disinfection or debridement of infected root canal systems with apical enlargement to permit revascularization and use of adult stem cells, scaffolds, and growth factors. Although the challenges of introducing endodontic tissue engineering therapies are substantial, the potential benefits to patients and the profession are equally ground breaking. Patient demand is staggering both in scope and cost, because tissue engineering therapy offers the possibility of restoring natural function instead of surgical placement of an artificial prosthesis. By providing an overview of the methodological issues required to develop potential regenerative endodontic therapies, we hope to present a call for action to develop these therapies for clinical use.     

Discolouration potential of endodontic procedures and materials: a review

Ahmed HMA, Abbott PV. Discolouration potential of endodontic procedures and materials: a review. International Endodontic Journal,?45, 883-897, 2012. ABSTRACT: Advances in endodontic materials and techniques are at the forefront of endodontic research. Despite continuous improvements, tooth discolouration, especially in anterior teeth, is considered an undesirable consequence following endodontic treatment as it creates a range of aesthetic problems. This article aims to discuss the intrinsic and internalized tooth discolouration caused by endodontic procedures, and to address the discolouration potential of materials used during root canal treatment, including root canal irrigants, intra-canal medicaments, endodontic and post-endodontic filling materials. In addition, the discolouration patterns caused by combined endodontic and nonendodontic aetiological factors are discussed. The recommended guidelines that should be followed by dental practitioners to prevent and manage tooth discolouration are also outlined.     

The outcome of endodontic resurgery: a systematic review

AIM: The aim of this paper is to establish an outcome standard for the assessment of healing radiographically after resurgery of persistent periradicular lesions by systematically reviewing the results from published studies. METHODOLOGY: The systematic review process requires the definition of predetermined criteria delineating the inclusion parameters of studies reviewed. Of 42 papers that were reviewed, eight qualified for inclusion. A weighted-average was calculated from the results taken from the eight eligible, peer-reviewed studies, published between 1970 and 1997. RESULTS: Three hundred and thirty patients out of 2375 (14%) from the included studies underwent resurgery for failure of healing as determined radiographically. Of this population, 35.7% healed successfully after resurgery, 26.3% healed with uncertain results and 38% did not heal at the one-year follow-up. CONCLUSIONS: Although there is nearly equal distribution of results between all categories, a 35.7% rate of healing as assessed radiographically is essentially equivalent to the 38% failure rate. This paper will allow an evaluation of current research results to establish an outcome standard and enable techniques and filling materials to be evaluated and compared. Furthermore, the outcome standard can assist in defining demographic and aetiological factors that contribute to the potential outcome of resurgery cases.