A pilot study comparing the effectiveness of conventional
training and virtual reality simulation in the skills
acquisition of junior dental students
Frank Quinn1, Paul Keogh1, Ailbhe McDonald2 and David Hussey3
1Dublin Dental School and Hospital, Lincoln Place, Dublin 2, Republic of Ireland; 2Eastman Dental Institute for Oral Healthcare Sciences, 256 Grays InnRoad, London WC1X 8LD, UK; 3Royal Victoria Dental School and Hospital, Royal Victoria Hospital Group Trust, Grosvenor Road, Belfast BT12 6BP, UK
The use of virtual reality (VR) in the training of operative dentistry isa recent innovation and little research has been published on itsefficacy compared to conventional training methods. To evaluatepossible benefits, junior undergraduate dental students wererandomly assigned to one of three groups: group 1 as taughtby conventional means only; group 2 as trained by conventionalmeans combined with VR repetition and reinforcement (withaccess to a human instructor for operative advice); and group3 as trained by conventional means combined with VR repetitionand reinforcement, but without instructor evaluation/advice,which was only supplied via the VR-associated software. Atthe end of the research period, all groups executed two class1 preparations that were evaluated blindly by expert trainers,under traditional criteria (outline, retention, smoothness, depth,wall angulation and cavity margin index). Analyses of resultingscores indicated a lack of significant differences between thethree groups except for scores for the category of outlineform, for group 2, which produced significantly lower (i.e. better)scores than the conventionally trained group. A statisticalcomparison between scores from two expert examiners
indicated lack of agreement, despite identical written and visualcriteria being used for evaluation by both. Both examiners,however, generally showed similar trends in evaluation. An anon-ymous questionnaire suggested that students recognized thebenefits of VR training (e.g. ready access to assessment, erroridentification and how they can be corrected), but the majorityfelt that it would not replace conventional training methods(95%), although participants recognized the potential for devel-opment of VR systems in dentistry. The most common reasonscited for the preference of conventional training were excessivecritical feedback (55%), lack of personal contact (50%) andtechnical hardware difficulties (20%) associated with VR-basedtraining.
Key words: virtual reality; skill acquisition; self-directed and self-paced learning; real-time feedback; objective evaluation.
Blackwell Munksgaard, 2003Accepted for publication 6 March 2002
FOR many decades, mechanical simulation deviceshave been used in training exercises, such as inaerial and marine aviation. They have also been
employed for the rehearsal of reaction protocols in
hazardous or potentially hazardous situations, thereby
eliminating the risk of injury, loss of life or damage to
expensive equipment. The earliest widespread use of
this technology was in competitive or hazardous
arcade games, e.g. aerial combat and car racing.
Associated with the rapid increase in computing
speeds and miniaturization of components (1), the
application of virtual reality (VR) has increased dra-
matically, particularly due to the ubiquitous presence of
the home computer. In the healthcare area, VR has had
limited integration into the acquisition of surgical skills
(e.g. suturing and keyhole surgery) and planning of
individual surgical procedures, particularly implant,
craniofacial and neurosurgical procedures (2, 3). With
respect to skills acquisition, VR-based training has been
utilized for the repeated use of a standardized simu-
lated patient (4).
Dental students are expected to be competent at a
large array of procedures on certification; indeed, in
many countries, no further training is compulsorily
required. This is very different from medical graduates
who are required to undergo extensive postgraduation
vocational training. The large number of undergradu-
ate dental procedures, which must be mastered, have
traditionally been tested by practical examinations. The
subjective nature of these tests, and their associated
stress, has led to many dental faculties replacing them
with competence tests (5, 6), which are organized,
within certain limits, at the students convenience
and assessed under objective or semiobjective criteria
Eur J Dent Educ 2003; 7: 1319Printed in Denmark. All rights reserved
(7, 8). The use of standardized VR scenarios may be
beneficial in the preparation and reinforcement of
required procedures (9). There may be additional appli-
cations for postgraduate students, to revise operative
and fixed prosthodontic procedures, and continuing
dental education. Once assessment criteria have been
universally accepted within the faculty, VR prepara-
tions and evaluations may be used to standardize
teachers and improve conventional teaching.
Computing speeds and costs have remained a con-
straining factor for the widespread use of specialized
systems to relatively small consumer groups, such as
dental undergraduates. In the last 5 years, however, a
dental patient simulator has been developed and
marketed for the training of undergraduate dental
students. This simulator consists of a conventional
torso and movable head, with integral maxillary and
mandibular jaws, which carry conventional plastic
teeth. There is an operatory-type light, suction and a
bracket table, carrying an ultra-high speed handpiece
and air/water syringe. With these components, train-
ing in operative dentistry can be undertaken in a
manner identical to conventional methods.
The novel components are light emitting diodes on
both the head and the handpiece and a tracking camera
that monitors head and handpiece movements (Fig. 1).
There are two personal computers: one to collate track-
ing information and the second to integrate all data and
execute the associated VR software. Finally, there is a
video screen which presents real-time virtual images to
the operator (Fig. 2).
At the time of this project, the systems software
allowed several operative and fixed prosthodontic pro-
cedures. It is postulated that the use of these options
would be superior to conventional training, with plastic
teeth, as the individual layers of the natural tooth are
represented in the virtual tooth, including dentinal
carious lesions. Preparations may be viewed from
many angles and at varying magnification; these fea-
tures may improve student understanding and self-
assessment (10, 11). The image of the virtual mouth and
tooth provide real-time information feedback of the
actual preparation cut on the tooth analogue. The
operator-controlled magnification may improve visua-
lization of cavity detail (12).
The software has an integrated database of theoretical
information, ranging from conventional principles of
cavity preparation to the pathology of the carious
lesion. This database is continuously accessible during
training sessions. In addition, there is a glossary of
dental terms, with associated multimedia explanations.
A final, and perhaps most important, benefit of this
simulation unit is that the software will analyze the
preparation, on request, and provide detailed written
and two-dimensional graphic evaluation of the pre-
paration (Fig. 3). Alterations may then be made and
the preparation re-evaluated. This encourages self-
directed and deep learning and self-paced skills
Fig. 1. Operator, torso with handpiece and display of VR mouth.
Fig. 2. The real-time display with magnified virtual tooth pre-paration.
Fig. 3. VR-based analysis of cavity preparation, compared to presetideal parameters.
Quinn et al.
acquisition (11, 13, 14). It is postulated that thesebenefits will aid the different styles and rates of learning
(15). This self-direction and self-pacing has been advo-
cated by many authorities due to the overloaded nature
of modern dental curricula and the bulimic nature of
conventional teaching methods (16). This term refers to
the cramming of large amounts of theoretical informa-
tion, in excessive detail and regurgitating it for an all
or nothing assessment. All too often, the information
is then discarded and never reviewed again. This
approach favours shallow or poorly retained learning.
The system administrator/course coordinator can
control access to specific, appropriate lessons. This
is managed via a programmable user database and
unique passwords. Operator access to lessons may
be limited to specific groups or during a particular time
frame. The duration allowed per individual procedure
may also be limited, if so desired. The procedures, once
selected, present clinical details and radiograph(s) for
perusal by the student; they may then proceed to the
virtual mouth and operative procedures completed.
This integration of clinical information and procedures
is believed to lead to improved knowledge acquisition
Individual sessions for students may be stored for
later review, either by the student or by an instructor.
The review is in the form of a real-time video playback,
with fast forward and rewind functions. The recorded
sessions may act as a positive feedback to the student,
illustrating improved technique with individual prac-
tice. If desired, recorded sessions may be used as
evidence of competence in clinical practice.
The Dublin Dental School received four Dental
Simulation Units and, finding only anecdotal evidence
of the benefits of VR in operative training, a pilot
research project was undertaken to quantify the bene-
fits, if any.
Methods and materials
The second year dental undergraduate class, consisting
of 32 students, was randomly assigned (by lottery) to
one of three groups. All students were given the same
introductory lecture and demonstration on the design
and instrumentation of conventional class 1 cavity
preparation. All students received conventional opera-
tive practice in the undergraduate laboratory. All were
supplied with a millimetre graduated periodontal
probe, a mouth mirror and a sharp probe. All prepara-
tions were completed with the same ISO standard pear-
shaped tungsten carbide bur (245), used at ultra-high
speeds and with continual water spray.
The group 1 students worked exclusively with con-
ventional phantom heads and teeth. These students had
continual access to an instructor, to provide feedback
and evaluation. Students performed repeated class 1
preparations for approximately 21 h.
Group 2 students also worked on conventional phan-
tom heads but, in addition, received 1 h of instruction
on the use of the dental simulation unit, and 4 h of
preparing multiple class 1 preparations on the lower
left first molar on the VR units. The students had real-
time feedback from the VR unit (Fig. 2) and had con-
tinual access to the same instructor (PK), but only for
technical instruction, real-time feedback and evalua-
tion. The students did not have access to preparation
evaluation options in the software. In addition to the
VR simulators exposure, the students had approxi-
mately 16 h of conventional phantom head teaching.
Group 3 students had identical conventional training
time as group 2, identical instruction in the use of the
dental simulation units and 4 h for preparation of multi-
ple class 1 preparations of the lower left first molar.
These students had access to the same instructor (PK),
but only for technical questions: feedback and prepara-
tion evaluation were provided by the units software.
The students also had access to the information data-
base and glossary. In addition to exposure to the VR
simulators, the students had approximately 16 h of
conventional phantom head teaching.
When all students had completed the allocated
operative time, all groups executed two class 1 cavities.
The individual teeth were coded anonymously and
submitted to two independent scorers. These two
experienced restorative academic trainers were not
informed of the nature of the project, but were supplied
with the ideal cavity dimensions and illustrations of
the desired cavity shape and dimensions on the lower
left first molar (17, 18).The scorers were requested to provide an ordinal
score (03 or 04) for the following aspects of the cavity
design: outline form, retention form, depth, smooth-
ness, cavosurface angulation (17) and cavity margin
index (19). The scores were qualitative, with 0 indicat-
ing an ideal preparation for that parameter, and 4 (or 3)
representing the aberrant performance.
The criteria for cavity evaluations were based on best
practice information (17, 18). These criteria, althoughsubjective, were intended to be as clear-cut as possible.
The criteria and scores are appended below:
Statistical analysesOn return of the scores, the code was broken and non-
parametric analyses (KruskalWallis/Wilcoxon Rank
Sum) of the data were undertaken with respect to the
Virtual reality in the training of operative dentistry
three groups. In addition, the agreement between the
two scorers was examined utilizing Kappa analyses.
Jump-in Software was employed for statistical analyses
(JMP IN, SAS Institute Inc).
A structured anonymous questionnaire was given to
groups 2 and 3, after they had completed all conventional
and VR exercises. This was designed to be non-directive
and to elucidate the subjective comparative opinions of
students who have been exposed to both conventional
operative training and the VR training units.
The results data were not normally distributed. Non-
parametric analyses failed to show statistically signi-
ficant differences between the three groups (Tables 1
and 2), except for the criterion outline form (p 0.037).The difference appears to be between groups 1 and 2
(Wilcoxon Rank Sum test).
Comparison between two expert examiners indicated
poor agreement. The best agreement was for cavity
smoothness, which gave a Kappa statistic of 0.156 and
the poorest was for cavity margin index, with the
Kappa statistic of 0.012. Nonetheless, both scorers failed
to show statistically significant difference for the eva-
luation criteria, except for outline form. One examiner
reported a relatively greater difference between the
three groups for this criterion, while the other exam-
iners scores fell just short of statistical significance at
the p 0.05 level. This disparity, combined with expo-
sure to conventional training by all groups, may have
masked differences between the three groups.
The anonymous questionnaire indicated that stu-
dents identified a relatively limited access to instruc-
tors, and an inconsistency in instructor evaluation, as
being unfavourable aspects of conventional training
(Table 3). Ninety-five percent of the individuals inexperimental groups 2 and 3 felt, however, that VR-
based training will not replace conventional training in
operative dentistry. The respondents selected technical
hardware difficulties, exce...