Guided Endodontics: Three-Dimensional Planning and Template-Aided Preparation of Endodontic Access Cavities

Summary

Guided endodontics describes a template-aided approach for access cavity preparation. The procedure requires cone-beam computed tomography and a surface scan to produce a template. An incorporated sleeve guides the drill to the target point. This allows the preparation of minimally invasive endodontic access cavities in calcified teeth.

Abstract

Pulp canal obliterations (PCO) are often a consequence of dental trauma, such as luxation injuries. Even though dentin apposition is a sign of vital pulp, pulpitis or apical periodontitis may develop in the long term. Root canal treatment of teeth with severe PCO and pulpal or periapical pathosis is challenging for general practitioners and even for well-equipped endodontic specialists. To ensure detection of the calcified root canal and avoid excessive loss of tooth structure or root perforation, static navigation using templates ("Guided Endodontics") was introduced a few years ago. The general workflow includes three-dimensional imaging using cone-beam computed tomography (CBCT), a digital surface scan, and superimposition of both in a planning software. This is followed by virtual planning of the access cavity and the design of a template that will guide the drill to the desired target point. To do this, a true-to-scale virtual image of the drill must be placed in a way that the tip of the drill reaches the orifice of the calcified root canal. Once the template has been fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM) or a 3D printer, guided preparation of the access cavity can be performed clinically. For research purposes, a postoperative CBCT image can be used to quantify the accuracy of the access cavity performed. This work aims to present the technique of static guided endodontics from imaging to clinical implementation.

Introduction

Pulp canal obliterations (PCO) are signs of vital pulp, and are often observed after dental trauma¹ or as a response to stimuli like caries, restorative procedures², or vital pulp therapy³. When no clinical or radiographic signs of pathology are present, root canal treatment is not indicated. In the long term, however, the remaining pulp tissue can develop a pathosis⁴. In cases where clinical or radiographic signs of pulpal or apical pathology are present, non-surgical root canal treatment would be the treatment of choice for tooth preservation.

Protocol

Approval or consent to perform this study was not required since the use of patients' data is not applicable. In this study, DICOM data from a maxillary model consisting of extracted, de-identified human teeth are used. Teeth were extracted due to reasons not related to this study.

1. Virtual access cavity planning

1. Start the digital planning program.
2. Right-click on Expert to choose the advanced mode.
3. Right-click on N.......

Discussion

The introduction of template-aided access cavity preparations in endodontics has brought immense progress to non-surgical endodontic treatment in teeth with PCO. Conventional access cavity preparation can be very time consuming⁵ and is prone to error in cases with severe PCO. In vitro studies and clinical case reports demonstrate the feasibility of the guided endodontics approach, generating satisfying results in terms of root canal detection and an overall low deviation between the plann.......

Materials

Name	Company	Catalog Number	Comments
Accuitomo 170	Morita Manufacturing	NA	CBCT machine
coDiagnostiX	Dental Wings Inc	Version 10.4	Planning software, which is mainly intended for implant surgery. Endodontic access cavities can be planned by adding the utlized bur to the implant database
Endoseal drill	Atec Dental GmbH	NA	Carbide bur, which is used for the guided access cavity preparation
StecoGuide Endo-Sleeve	steco-system-technik	REF M.27.28.D100L5	Sleeves, which are inserted into the fabricated template
TRIOS 3	3Shape A/S	NA	Surface scanner
P30	Straumann	NA	3D Printer
P pro Surgical Guide Clear	Straumann	NA	Light-curing resin for the additive manufacturing