Guided Endodontics in Root Canals with Complex Access: Two Case Reports

Effectiveness of guided endodontics when accessing root canals containing fiberglass posts: an in vitro study

The present study aimed to compare the performance of a 3D-endodontic guide (EG) and a conventional technique on the access of root canals containing fiberglass posts. Thirty single-canal lower human premolars were endodontically treated, filled using the single-cone technique, and prepared for fiberglass post luting. The teeth were positioned in the alveoli of human mandibles and cone beam computed tomography (CBCT) examination was performed. The specimens were randomly distributed (n = 10) according to the root canal access technique: control group (GC)-no access; conventional access group (GCA)-root canal accessed with spherical diamond burs and ultrasonic inserts; and EG group (GEG)-root canal accessed with bone graft/anchorage drills and EG. At the end of the root canal access, new CBCT examination was performed to assess the root canal walls' thickness and the volume of dental tissue removed during the fiberglass post removal. The time required for the access was also recorded. The data were submitted to statistical analysis (Kruskal-Wallis and Mann-Whitney tests, α = 0.05). GCA promoted greater deviation than the GEG (p < 0.05) and resulted in greater removal of the root canal walls. The volume of dental tissue/fiberglass post removed, deviations promoted, and the time spent were significantly lower (p < 0.05 and p < 0.001, respectively) in GEG than in GCA. The use of the EG provided a lower volume of dental tissue removed, less deviation from the original root canal path, and less time for endodontic access when compared to conventional access technique.

Evaluating the concept of three-dimensional printing guided endodontics in the dog

Introduction

Guided endodontics represents an effective method for achieving safe and reliable endodontic surgery in human medicine. However, it is rarely employed in small animal dentistry. This study employed finite element analysis and three-dimensional (3D) printing techniques to explore the feasibility of guided endodontics in Beagle mandibular teeth.

Methods

The methodology included the processing of Computed Tomography (CT) data, the creation of mathematical and 3D printing templates of the root canal pathways, and the evaluation of dog 3D printing guided endodontics compared with classic root canal method using radiograph.

Results

In this experiment, the coordinates of the central point of pulp crown and apex point for each tooth were recorded. Based on the extension line of the central point of dental root canal orifice and the apex point, guided endodontic templates were designed on each root canal of 20 teeth in the Beagle mandible. Among them, the average relative deviation of guided endodontics and classic root canal method was 4.28%  ±  2.75%, and the mean angular deviation was 1.90  ±  0.25°.

Discussion

Our research indicated that dog 3D printing guided endodontics has accurate position, direction, and length, which may assist veterinary dentistry in root canal treatment in small animals.

Comparison of selective laser melting and stereolithography etching templates for guided endodontics

Background

With the increasing application of guided endodontics to treat complex root canal treatment, the entire process of root canal treatment has become more precise, reducing damage to tooth structure and improving success rates. However, due to the limitations of the operating space, the use of guided endodontic templates in posterior root canal treatment is less common. This study aims to compare the accuracy and reliability of selective laser melting (SLM) and traditional stereolithography etching (SLA) guided endodontic templates for posterior root canals, providing better treatment strategies for posterior root canal treatment.

Methods

The teeth were randomly assigned to either SLM or SLA group. Preoperative cone-beam computed tomography (CBCT) and a three-dimensional (3D) scanner were used to establish the 3D root canal system and the accurate occlusal models of the teeth. The virtual access to the canal access was designed using Mimics 19.0 and 3-Matic 11.0. The endodontic access was performed based on either SLM or SLA templates. The accuracy of endodontic preparation was measured in three-dimensions by calculating deviations from planned accesses. The template height and tooth substance loss rates in each group were measured.

Results

SLM-guided templates have a low average deviation at the entry point and apical portion of the bur of total posterior teeth (including premolars and molars) and individual molars (P < 0.05). Moreover, there was a significant difference in angular deviations and height of template in total posterior teeth and individual molars (P < 0.05). The mean substance loss rate of the SLA group was slightly greater than that of the SLM group, but the difference was not statistically (P > 0.05).

Conclusions

SLM-guided endodontics provides a more predictable and precise location of root canal orifice for the treatment of posterior teeth.

Expert consensus on digital guided therapy for endodontic diseases

Digital guided therapy (DGT) has been advocated as a contemporary computer-aided technique for treating endodontic diseases in recent decades. The concept of DGT for endodontic diseases is categorized into static guided endodontics (SGE), necessitating a meticulously designed template, and dynamic guided endodontics (DGE), which utilizes an optical triangulation tracking system. Based on cone-beam computed tomography (CBCT) images superimposed with or without oral scan (OS) data, a virtual template is crafted through software and subsequently translated into a 3-dimensional (3D) printing for SGE, while the system guides the drilling path with a real-time navigation in DGE. DGT was reported to resolve a series of challenging endodontic cases, including teeth with pulp obliteration, teeth with anatomical abnormalities, teeth requiring retreatment, posterior teeth needing endodontic microsurgery, and tooth autotransplantation. Case reports and basic researches all demonstrate that DGT stand as a precise, time-saving, and minimally invasive approach in contrast to conventional freehand method. This expert consensus mainly introduces the case selection, general workflow, evaluation, and impact factor of DGT, which could provide an alternative working strategy in endodontic treatment.

Application of an Endodontic Static Guide in Fiber Post Removal from a Compromised Tooth

Removing a fiber post from a root canal that requires endodontic retreatment is often very challenging. Conventional freehand techniques for removing fiber posts are time-consuming, sometimes result in iatrogenic errors, and heavily rely on the practitioner's experience. The endodontic static guide can be an alternative method. While the use of an endodontic 3D-printed static guide for fiber post removal has been reported as highly successful, it can also cause complications. Skipping any critical steps during the guide construction or its clinical application can lead to errors. This case report presents the saving of a compromised tooth with a fractured fiber post and a periapical lesion around the apex through the use of an endodontic static guide for fiber post removal. This study describes possible sources of error that may happen during construction and clinical use of the guide.

Effectiveness of guided endodontics in locating calcified root canals: a systematic review

OBJECTIVES

The aim of this study is to answer the question: "Is guided endodontics an effective technique for locating calcified canals?".

METHODS

A systematic search was carried out by two independent authors in PubMed, Web of Science, Scopus, and Scielo databases. According to the PIOS criteria, observational studies, ex vivo studies, clinical case reports, and case series were included. The quality of evidence of observational studies, case reports, and case series were assessed using the respective Joanna Briggs Institute critical appraisal tool, and a previous personalized tool was used to assess the quality of the ex vivo studies.

RESULTS

Forty-five studies were included. Of them, 21 were clinical case reports, 11 case series, 12 ex vivo studies, and 1 cohort study. Of the 45 studies analyzed, 43 reported that guided endodontics is an effective and precise technique to access the permeable portion of calcified canals. Only 2 studies report accidents or failures related to the use of endodontic guides.

CONCLUSIONS

Guided endodontics allows conservative access, minimizes accidents, and is effective in locating calcified canals; however, it is a technique that still presents limitations.

CLINICAL RELEVANCE

Guided endodontics has been proposed as a simple and effective technique for the treatment of calcified canals. The expansion of this technique requires knowing its benefits and limitations to ensure success and avoid accidents.

Guided Endodontics: A Literature Review

The main objective of this paper is to perform an updated literature review of guided endodontics based on the available up-to-date scientific literature to identify and describe the technique, its benefits, and its limitations. Four electronic databases (PubMed, Scopus, Science Direct, and Web of Science) were used to perform a literature search from 1 January 2017 to 13 May 2022. After discarding duplicates, out of 1047 results, a total of 29 articles were eligible for review. Guided endodontics is a novel technique that is currently evolving. It is applied in multiple treatments, especially in accessing and locating root canals in teeth with pulp canal obliteration, microsurgical endodontics, and removing glass fiber posts in endodontic retreatments. In addition, it is independent of an operator's experience, requires less treatment time for the patient, and is more accurate and safer than conventional endodontics.