Cone beam computed tomography in implant dentistry: recommendations for clinical use

Abstract

Background: In implant dentistry, three-dimensional (3D) imaging can be realised by dental cone beam computed tomography (CBCT), offering volumetric data on jaw bones and teeth with relatively low radiation doses and costs. The latter may explain why the market has been steadily growing since the first dental CBCT system appeared two decades ago. More than 85 different CBCT devices are currently available and this exponential growth has created a gap between scientific evidence and existing CBCT machines. Indeed, research for one CBCT machine cannot be automatically applied to other systems.

Methods: Supported by a narrative review, recommendations for justified and optimized CBCT imaging in oral implant dentistry are provided.

Results: The huge range in dose and diagnostic image quality requires further optimization and justification prior to clinical use. Yet, indications in implant dentistry may go beyond diagnostics. In fact, the inherent 3D datasets may further allow surgical planning and transfer to surgery via 3D printing or navigation. Nonetheless, effective radiation doses of distinct dental CBCT machines and protocols may largely vary with equivalent doses ranging between 2 to 200 panoramic radiographs, even for similar indications. Likewise, such variation is also noticed for diagnostic image quality, which reveals a massive variability amongst CBCT technologies and exposure protocols. For anatomical model making, the so-called segmentation accuracy may reach up to 200 μm, but considering wide variations in machine performance, larger inaccuracies may apply. This also holds true for linear measures, with accuracies of 200 μm being feasible, while sometimes fivefold inaccuracy levels may be reached. Diagnostic image quality may also be dramatically hampered by patient factors, such as motion and metal artefacts. Apart from radiodiagnostic possibilities, CBCT may offer a huge therapeutic potential, related to surgical guides and further prosthetic rehabilitation. Those additional opportunities may surely clarify part of the success of using CBCT for presurgical implant planning and its transfer to surgery and prosthetic solutions.

Conclusions: Hence, dental CBCT could be justified for presurgical diagnosis, preoperative planning and peroperative transfer for oral implant rehabilitation, whilst striving for optimisation of CBCT based machine-dependent, patient-specific and indication-oriented variables.

Keywords: Cone beam computed tomography; Dental implants; Guidelines; Presurgical planning; Radiation dose; Virtual patient.

Fig. 1

Availability of peer-reviewed articles on the use of CBCT is dentistry and more specifically in the pre- and postsurgical phases of implant dentistry (PubMed output up till November 30 2016). Roughly, every fourth article published on CBCT is related to the use of CBCT in implant dentistry, with two out of three on the presurgical use of CBCT, with a vast majority on the application of CBCT for presurgical planning and transfer to implant placement

Fig. 2

Availability of peer-reviewed articles on the use of CBCT dentistry in implant dentistry, focused on studies performed on human subjects (PubMed output up till November 30 2016). The articles are then divided in three main areas of application: Presurgical and postsurgical imaging and image quality (IQ) and dose evaluation. A Venn diagram was used to highlight the intersections of these research areas

Fig. 3

Flowchart of the decision path that clinicians need to follow to find the optimal acquisition set-up of CBCT images in daily practice

Fig. 4

Variation in radiation doses of dental CBCT in relation to dose ranges of other orofacial imaging modalities and natural background radiation

Fig. 5

Dose optimization strategy algorithm/flowchart (adapted from [17])

Fig. 6

Exponential growth in publishing scientific papers in relation to dental applications, since its first appearance in 1998, with a fourth of the studies on CBCT in implant dentistry, following the same growth tendency (pubmed output up to 2016)

Fig. 7

Double mental foramen visible via volumetric imaging of the jaw bone, presenting a risk for nerve damage, if left undetected

Fig. 8

Implant in the mandible showing some beam hardening artefact, and in addition a position at the roof of the incisive canal, causing neurosensory disturbances