ENDO, 01/2020

Historically the idea of possible links between dental infections and systemic diseases, as expressed by the medical profession, impacted clinical dentistry and millions of patients well over 100 years ago. However, a small core of dental professionals strove to retain teeth by scientifically refuting the concepts of focal infection and elective localisation; and slowly the conflagrations of these theories began to be reduced to but a few smoking embers. However, over the years these embers have continued to smoulder, and this once-thought-dead controversy has been revived, fanned by the winds of questionable science, charlatanism and the use of social media platforms to misinform both the profession and the public. This presentation will highlight a brief history of this dilemma, along with current thought from a realistic perspective. Keywords: dental infection, focal infection, social media, systemic disease and infection

Classifications in medicine/dentistry are required so that clinicians can properly diagnose and then adequately treat their patients. However, they are also important for scientists to study the prevalence and the etiopathogenesis of diseases, as well as their prognosis, course and treatment. This brief review is based on the four consensus reports (Chapple et al, 20181, Papapanou et al, 20182, Jepsen et al, 20183, Berglundh et al, 20184) and the introduction (Caton et al 20185) presenting the results of the World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions. The consensus conference was jointly organised by the American Academy of Periodontology and the European Federation of Periodontology and conducted in November 2017 in Chicago. It was attended by 110 experts from all over the world. The results were published in the Journal of Periodontology and the Journal of Clinical Periodontology in June 2018. Keywords: classification, dental implant, peri-implant disease, periodontal disease, periodontology

Objective: In recent years attention has been given to the presence of the middle mesial canal (MMC) in mandibular molars. This attention has caused a proliferation of case reports and even some systematic reviews. However, little attention has been paid to the actual presence of a 'separate canal', as opposed to the presence of an anastomosis that is patent or partially calcified that allows the penetration of an instrument. Furthermore, due to the complexity of this anatomical entity, even less has been addressed regarding the thorough management of this challenge and its potential impact on procedural outcomes. The aim of this review was to address the latter issues in an attempt to clarify and provide clinical directives. Materials and methods: Case reports and series published on MMCs were included and relevant data was extracted. They were analysed and interpreted to address the aim of the review. Other pertinent published data regarding true MMCs versus anastomoses were also reviewed. Results: Published case reports and series were majorly on true MMCs. However, evidence showed that the majority of MMCs were anastomoses. The clinical importance of managing anastomoses is emphasised. This paper also identifies areas that require more research and evidence regarding the management of MMCs. Keywords: anatomical irregularities, mandibular molars, middle mesial canals, procedural outcomes

Cone beam computed tomography (CBCT) is a significant tool in the diagnosis and treatment planning of challenges under the scope of endodontics and in assessing outcomes in particularly complicated cases, although the vast majority of published studies focus on periapical healing following nonsurgical root canal procedural, surgical outcomes and resorptive repair. However, one of the true indications for the use of CBCT is the diagnosis and management of dentoalveolar trauma, especially root fractures. While there is controversy on the ability of CBCT to clearly identify vertical fractures, few studies address the use of CBCT focusing on the nature of horizontal tooth trauma, and in particular its outcome. Keywords: cone beam computed tomography, CBCT, coronal luxation horizontal root fracture, long-term outcomes, osseous healing, pulpal diagnosis, radicular repair

Objectives: The present randomised clinical study aimed to evaluate the effect of OneShape and ProTaper Next rotary systems on the removal of endotoxins from root canals of teeth with asymptomatic necrotic pulp. Materials and methods: 30 patients were randomly allocated into two groups (n = 15) according to the type of rotary system used in the mechanical preparation: group OneShape (OS) or group ProTaper Next (PN). Samples were collected before and after mechanical preparation and the quantification of endotoxins was conducted using the human enzyme-linked immunosorbent assay (ELISA) kit. Statistical analyses were performed using the Mann-Whitney U test to compare the two groups, and the Wilcoxon signed rank test to study the changes after treatment within each group. The significance level was set at P ≤ 0.05. Results: The group OS showed a statistically significant reduction in the endotoxin levels after treatment (P < 0.001, effect size = 0.880). In the PN group there was a statistically significant reduction in endotoxin levels after treatment (P < 0.001, effect size = 0.931). In the OS group a statistically significant median percentage reduction in endotoxin levels was observed compared with the group PN (P < 0.05). Conclusions: ProTaper Next was more effective than OneShape in reducing endotoxins from root canals of teeth with asymptomatic necrotic pulp. Keywords: multi-file system, necrotic, OneShape, ProTaper Next, root canal, single-file system

Objective: Restoration of fractured root canal-treated maxillary incisors based on recent advances in adhesive dentistry and minimal invasive principles, which are topics of great importance. In particular, the aim of the present study was to evaluate the fracture resistance of a corono-radicular direct composite restoration compared with fibre post composite restorations and direct conventional composite restorations. Materials and methods: A total of 45 freshly extracted sound maxillary central incisors were used in the study. The teeth were randomly divided into three groups of 15 each. The groups were: group I (CDC), conventional direct composite postendodontic restoration; group II (FPC), fibre post placement and direct composite postendodontic restoration; group III (CRC), corono-radicular composite postendodontic restoration. The fracture resistance was measured using a universal testing machine and a 130 degrees angle of loading. Results: One-way ANOVA depicted a significant difference (P = 0.028) among the three groups with the mean fracture load of group CRC being the highest, at 1045.2 ± 355.7 N. The FPC group had the significantly least fracture resistance load, with 426.7 ± 245.3 N. Conclusions: Within the parameters of this study, the corono-radicular composite restorations had significantly higher fracture resistance than conventional direct composite and fibre post restorations when 50% of the crown structure was lost in fractured root canal-treated maxillary incisors. Keywords: coronal restoration, glass fibre post, monoblock effect, monolithic restoration, root canal treated teeth

The endodontic management of enamel mineralisation defects, such as amelogenesis imperfecta, may be challenging because the root canal configuration of affected teeth is often abnormal. This report of two cases illustrates the difficulties of cleaning, shaping and obturating the root canal system of teeth with amelogenesis imperfecta. Keywords: amelogenesis imperfecta, hypomineralisation, pulpal anomalies, root canal anatomy

With the advent of three-dimensional (3D) printing, there has been an enhanced focus on the creation of models in dental education. These models range all the way from simple teeth for predoctoral educational programmes to more sophisticated models that can be used in both continuing educational settings and in postgraduate/graduate specialty programmes. In this article, the development of a model to teach the decompression technique is described along with a case report that demonstrates the application of this procedure. Keywords: 3D-printed model, CBCT, cyst, decompression, educational model, guided endodontics, minimally invasive