Influence of motivation and a new digitized training program on undergraduate dental students during preclinical scaling training

The main proceeding of an efficacious cause-related periodontal therapy is the subgingival removal of biofilms and/or hard deposits (mineralized biofilms) [1, 2]. The treatment effect is consistent, irrespective of the choice of instrument (sonic/ultrasonic vs. hand) or mode of delivery (full-mouth vs. quadrant) [3]. Dental students need intensive training in manual skills on manikin heads under clinical conditions before working in real clinical conditions [4‐6]. Efforts have been made to improve the efficiency and precision of complex procedures in medicine. With the help of virtual planning visualization, the complex anatomy of the human body is easier to understand [7]. Correspondingly, it seems that conventional techniques have begun to move into the research background. However, until now, these techniques have remained predominant in routine practice [8]. Therefore, it is not surprising that the European Federation of Periodontology (EFP) recommends in their clinical practice guidelines [1] the proper way for a basic dental program to perform conventional scaling and prophylactic procedures. The challenge is to correctly and effectively apply suitable instruments and to positively support the learning process by motivating and strengthening personal drive [9]. Although artificial models do not simulate a perfect realistic situation, training is an important step in reducing treatment time and improving results [10]. In previous studies from our dental school (University of Kiel), the learning curves of scaling with Gracey curettes (GRA) and power-driven instruments using manikin heads with a conventional training program (CTP) [10] or with the help of a self-developed systematic digitized and interactive training program (DTP) [11] have been assessed. We assume that new digital interactions might have an effect on the motivation and self-assessment of the participants. Both studies on the two training concepts are based on the same current state of evidence regarding the choice of hand instruments. However, the investigation of CTP published nearly 20 years ago concerned power-driven instruments (Periopolisher System, Hawe Neos Dental, Bioggio, Schweiz) and not a sonic scaler, as is used in the DTP study. These instruments were common in scaler systems but are no longer marketed today. Thus, we were not able to directly compare both training concepts with regard to effectiveness and motivational effects.

The aim of the study was to evaluate the training effect of CTP and DTP with regard to scaling with either a sonic scaler (AIR) or GRA. Furthermore, the participants of both training concepts assessed themselves with regard to their subgingival scaling effort, treatment time, handling, root surface roughness/destruction and effectiveness.

Forty-nine participating students were without randomization assigned, (1) in their 7th semester in the autumn of 2018 to the CTP group, while the students present in the spring of 2019 were assigned to the DTP group. In the DTP group, one student refused to take part in the study (n = 30). In the CTP group, one student failed to finish the training phase (no data at the test visit because of breaks during the preclinical course) (n = 19).

Data for all the participants regarding age, gender, handedness, regularity of playing computer games/consoles and previous dental/technical or medical education were retrieved pseudonymously.

In the present study, we found that the DTP participants were 5–10% more efficient and needed less time for RCE-b with both groups of instruments than were CTP participants. Additionally, we identified two predictors of successful cleaning: DTP (p = 0.017) and pre-education in medicine/dentistry (p = 0.05). In contrast, regular computer/console play (p = 0.025) worsened the cleaning performance of our undergraduate students.

However, both training groups were similarly efficient for RCE-d, i.e., 78–88% (Table 2). A possible reason for the higher effectiveness for RCE-b but not for RCE-d would be the tactile dedication of hard deposits. Hence, systematic work is of less importance than for the removal of biofilms. In particular, curettes allow tactile control [13]. In addition to standardized working parameters [14], the efficacy of biofilm removal depends on experience [10, 12]. Another unusual significant difference for RCE-b was found at the tooth level, as the CTP group was more effective in the molar region with GRA than the DTP group (RCE-b: 79.82 (20.85)% versus 72.08 (23.35)%, p = 0.001). Furthermore, against current knowledge [15], GRA leads to better cleaning efficacy in molars in both training groups. An explanation could be that only the outer root surfaces but not the furcation area of the involved molars were assessed in the current study. Hence, accessibility for both types of instruments was equally good [16].

The total training phase took the same amount of time, but the training with DTP needed less supervision time by fewer supervisors (DTP in the ratio 1:10 versus CTP in the ratio 1:4), which was one goal of developing DTP.

In general, the effectiveness of subgingival scaling depends not only on the type of instrument and the anatomical conditions (e.g., tooth type) but also on the students’ skills in handling the instruments. Other studies have considered differences in the participant's experience and relate them to the success of treatment [17, 18]. High motivation seems to be a further prerequisite for improved performance. For example, the study by König, Ruhling [19] showed that motivated groups achieve on average approximately 25% higher cleaning performance when removing simulated deposits than groups that were less motivated during training. The authors showed that students who had received very comprehensive support were much more realistic about their own effectiveness. In contrast, the less motivated group overestimated their own results by more than 20% [19]. In the current study, a similar effect of motivation by DTP can be assumed, whereby the benefit is essentially lower in total and more specifically distributed for the two different groups of instruments (Table 2).

The decision of which instrument for subgingival scaling should be used has to be placed in the hands of the operator. The choice should be based upon the experience, skills and preference. However, to make the decision, a realistic self-assessment is of major importance. Expectations of success and willingness to perform well are relevant factors among the many aspects of performance motivation [20]. An operator who does not expect to be successful is not motivated to perform well. From the point of view of learning psychology, performance motivation depends on intrinsic and extrinsic factors [1]. Intrinsic motivation seems to be particularly important for learning. It leads to more intensive information processing, which depends on systematic knowledge, conceptual understanding and the recognition of superordinate relationships. In addition to the mentioned goal of reducing the necessary effort for teaching, another goal of DTP was to strengthen the motivation of undergraduate students. Self-assessment of one's own performance and feedback from the instructors appear to be essential components of a formative learning process and the basis for further development. As described above, all the participants were asked to use a questionnaire to assess how they felt when working with GRA and AIR or how efficiently they thought they were working. We showed that the participants of the more self-reliant DTP group more often assessed their effectiveness and time requirements more realistically than did the other participants. However, the participants in the CTP group preferred AIR for higher effectiveness.

Previously, we found that the learning curve for RCE-b was steeper with AIR than with GRA in DTP [11]. Without training, only 27% of all the students reached a cleaning performance of at least 70% when using AIRs (GRA: 40%). We have already observed a similar phenomenon in previous studies [10, 12]. A possible explanation might be the prior knowledge of using a universal curette and inexperience in using powered equipment. Furthermore, this could also justify why the CTP group preferred the AIR rather than the DTP group, which also judged the mechanical instrument to be more effective and less tiring (Table 4). At the end of the training phase by DTP, 30% removed at least 70% of simulated biofilm with GRA compared to the participants in the CTP group. When using AIR, this difference was approximately 42%. Interestingly, for RCE-d, an almost similar percentage of participants of 80–90% removed hard deposits with an efficacy of ≥ 70%. Therefore, it should be mentioned that (1) hard subgingival deposits are always easier to detect as biofilms and (2) it is important to learn tactility for scaling.

In addition, the CTP group stated before the evaluation that they considered using AIR less tiring than the DTP group. After using both types of instruments, the DTP group assessed themselves in the same way as the CTP group (statistically no differences for GRA/AIR). However, the CTP participants overestimated their own effectiveness, as they worked significantly less efficiently with both instruments (p ≤ 0.01) than the DTP group. Additionally, the CTP group was slower but estimated the required time analogously to the DTP group (GRA p = 0.067 and AIR p = 0.028). This estimation can possibly be explained by the fact that the CTP group is not as proficient in the use of GRA as the DTP group. Hence, it can be concluded that using AIR is less tiring and has a lower learning curve. Participants in the DTP group recognized that the use of AIRs takes more time when used correctly and can be perceived as tiring (and noisy) over this period of time. In addition, the self-assessment in DTP might be better, as the participants could rely less on support from supervisors and hence had to help themselves or help each other more often.

The most important limitation of our simulation is that the results cannot be transferred to a clinical setting directly [17]. RCE can only be assessed in an in vitro setup with simulated biofilms and hard deposits on artificial teeth. Corresponding to our earlier study regarding the learning curve by DTP [11], DTP seems to be helpful for inexperienced users. Our study evaluated DTP versus CTP in routine teaching. We did not focus on the best possible effectiveness of scaling by undergraduate students or measuring side effects such as root destruction [21].

However, the effect of digital media on training in dentistry should not be overestimated. Both an innovative teaching concept and the ability to realistically self-assess performance play important roles in the learning process, similar to other factors (general stress in studies, different teaching methods, etc.) [19]. Overall, the additional effort for digitizing teaching (e.g., higher costly technical equipment, time to organize) pays off in terms of both effectiveness and time expenditure by higher motivation of the students and lower supervision key.

Within the limits of the study, it can be concluded that DTP is helpful in training subgingival scaling in undergraduate dental students. The DTP participants assessed themselves more realistically, and they cleaned significantly better overall than did the CTP group. A further improvement and even a permanent increase in motivation might be achieved by a direct digital feedback system or with, e.g., personalized digital animation, which must be evaluated in future studies.