Page 27 - RADC 2023

DEVELOPMENT
DPHC(D) Digital Intra-Oral Scanner Trial
Major Henry Walker
In March 2023, DPHC took delivery of 3Shape Trios 3 Digital Intra-Oral Scanners (DIOS), alongside 3D Printing and Milling capabilities, marking the largest digital transformation of military dental care since digital radiography was integrated in 2015. The initial deployment of DIOS within DPHC(D) was conceived as a 5-year
trial using the Tier 2 Practitioners of the Restorative Managed Clinical Network to lead the transformative change across 7 Dental Centres (DCs); Edinburgh, Catterick, Cosford, Larkhill, HMS Drake, Aldershot/ DCRD and Colchester.
For those not familiar with DIOS, the system consists of a laptop, an intra-oral camera with removable autoclavable scanner tips and calibration equipment as shown in Figure 1. The DIOS generates a 3D image dataset of the patient’s dentition by knitting together thousands of images as shown in Figure 2. The 3D image can be used chairside for patient assessment, diagnosis, treatment- planning, communication and improving the consent process. Alternatively, the dataset can be transferred via the system’s cloud to both our internal laboratory (housed at the DCRD) or to our external laboratory partner, Swift, for the construction of digital workups or dental prostheses.
DIOS use in civilian practice has grown exponentially, alongside digital prosthetic manufacturing processes, using 3D printing
Figure 1: the DIOS set up within a dental surgery
Figure 2: anonymised DIOS from the 3Shape Website
and milling technologies. Now, as an avid DIOS convert, I am fully aware of the benefits but will keep my praise succinct. Firstly, DIOS really enhances the communication between the patient and clinician as patients’ diagnoses can be discussed with the aid of
a 3D image of their mouth to enhance their understanding of their dental health. This
has the potential to improve ownership of their dental health as well as helping the consent process. A good example comes with the ability to overlay new scans onto
old to monitor changes, such as in cases of non-carious tooth surface loss. Additionally, the clinician can assess and treatment plan without the patient present which adds flexibility.
DIOS provides game changing accuracy with a recent systematic review finding
that 67% (16 of 24) of studies analysed showed DIOS to be more accurate, in microns, than conventional impressions (Chandran et al., 2019) and aligns with our own audit data which shows that 97% of scans produce models with no deficiencies in critical areas and no processing artefacts which prevent hand articulation of printed models. Additionally, DIOS reduces the risk of errors at the impression, model pouring and prostheses construction phases, particularly as most dental laboratories will now convert conventional impressions (and their inherent errors) into digital datasets to aid manufacture. Our own audit, of over 200 dental prostheses constructed digitally, found that 93.4% were fitted at first appointment, with 74% requiring no adjustments. I can attest to hearing gold crowns and cobalt- chrome partial dentures clicking into place in a geekily satisfying way.
Secondly, the efficiencies, both financial and in time saved, around dental laboratory work administration are significant. DCs
no longer pour, package, post and break models to the laboratory and there is only the return posting of the laboratory work
to contend with. The positive impression realised by DIOS ensures that the dentist “sees” what the technician “sees” and eliminates many of the classic debates about where fault lies; for instance, errors being due to sub-optimal impression quality versus sub-optimal model trimming or margination of prosthesis. The only limiting factor on laboratory work turnaround time is now the dental laboratories processing timelines
and the DC’s ability to see the patient for a
fit appointment. Early audit data shows that for a snapshot of 151 completed laboratory work cases, the median time from DIOS to
fit was 25 days, with 67% of the 151 cases being fitted in under 31 days. Furthermore, 25 of these cases were completed in 14
days or under. The key advantage is that a fit date can be predictably booked in at the impression appointment. The data supports the efficiencies we are observing in practice and for DPHC(D) as a globally dispersed organisation, the benefit to patients’ care is huge.
Thirdly, the efficiencies from interoperability of dental teams are game changing. 3D digital models of patients’ teeth can be shared immediately between colleagues to support restorative or orthodontic referrals, thus speeding up response times, streamlining patient care pathways and minimising
patient travel and subsistence costs. Within DPHC(D) DIOS application could be utilised at a Service Persons’ Initial Dental Inspection (IDI), to ensure a completely accurate
forensic record as well as a baseline record
of the patients’ dental health which can be referred to throughout their time in service. There is also growing evidence to support
the accuracy of diagnosing using DIOS (Angelone et al., 2023) which could be utilised within the IDI workflow of Project MOLAR/ MOL(AIR) dental practices.
DIOS within DPHC is not without its limitations. Presently, the units are not integrated with DMICP and this adds
layers of complexity to ensure that DIOS
data is recorded effectively in the patient records. The initial concept, although small
in scale, has been 6-years in the-making
and highlights the challenges involved with bringing new patient technologies into the Military (or any publicly funded) health care service. The real challenge is now to ensure that the benefits of DIOS are recognised by both DPHC and the single Services, so that support is gained for broader military role-out.
The future vision is for DIOS to be integrated into all DPHC DCs of four chairs
or more with the aspiration that all recruits will be scanned on joining the military and the dentist-monitoring of their dentition
aided by periodic scanning with objective measurements of deterioration. The US Army already deploy DIOS and 3D printing in the Role 2 land environment and undoubtedly the sS will seek to develop similar capabilities in both the Deployed Land and Afloat arenas.
Alginate tubs are full and gathering dust, model trimmers are seizing up... ”The King is dead....long live the King”.
References
Chandran, S., et al. (2019) ‘Digital Versus Conventional Impressions in Dentistry: A Systematic Review,’ Journal of Clinical and Diagnostic Research, 13(4), pp. 1-6.
Angelone, F., et al. (2023) ‘Diagnostic Applications of Intraoral Scanners: A Systematic Review,’ J. Imaging, 9(7), p. 134.
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