A pilot study comparing the effectiveness of conventional training and virtual reality simulation in the skills acquisition of junior dental students

  • Published on

  • View

  • Download


  • 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

    and retention.

    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...


View more >