Background

Over the past few years, digital technologies have significantly contributed to clinical procedures and laboratory methodologies in dentistry. The introduction of intraoral scanners and advanced fabrication processes such as computer-aided design and manufacturing (CAD/CAM) technologies and 3D printing has enabled the substitution of conventional metal frameworks [1]. Compared to conventional dental technology (CDT), digital dental technology (DDT) has increased the time efficiency of laboratory fabrication [2, 3]. The digital workflow has demonstrated better clinical efficiency when considering impression time, patient preference, and time efficiency [3]. Most British and Irish dental technicians reported using some form of CAD/CAM technology in their workflow [4]. Global digitalization has changed the dental industry and the working content of dental technicians in Taiwan. A previous study investigating the acceptance of CAD/CAM among Taiwanese dental technicians reclaimed that CAD/CAM was the future of the dental industry and would likely replace most of the manufacturing processes currently undertaken by dental technicians. [5]

Few studies have focused on occupational diseases or injuries of dental technicians in dental laboratories. Previous studies reported that dental technicians exposed to sandblasting have a higher risk of pneumoconiosis [6] and also have an increased risk of developing hand eczema owing to frequent exposure to uncured (meth)acrylates and handwashing [7]. A high prevalence of work-related musculoskeletal disorders [8] and the infection risk of dental impressions [9] have also been reported.

Dental technicians are an important part of dental teams; they are licensed dental auxiliaries in many countries, including Taiwan [10]. However, compared to dentists or dental hygienists/therapists, few studies have investigated the occupational health issues of dental technicians [11]. In the UK, a study revealed that even though dental technicians showed a high level of job satisfaction, < 50% of them felt adequately valued as individuals in the dental team and as a professional group [12]. Another common issue of occupational health is burnout, which is a prolonged response to chronic emotional and interpersonal stressors in a job [13]. It is common among individuals with people-centered occupations [14]. A previous study in Taiwan showed a moderate burnout level among dentists and a high burnout level among dental assistants in the context of national health insurance. The most stressful event for dental staff was identified to be “managing medical disputes or lawsuits” [15]. Likewise, some studies have revealed that managing anxious or difficult patients is associated with burnout in dental staff [16, 17]. Moreover, previous studies in medical settings have shown that burnout and job satisfaction are both associated with turnover intention [18,19,20,21,22].

In Taiwan, dental technicians predominantly work in laboratories, and their burnout levels may differ from those of other dental team members. Furthermore, the industry’s trend toward digitalization may impact their working contents and occupational health; however, to our knowledge, no study has explored these issues. The purpose of this study was twofold: (1) to explore the working characteristics and DDT experiences of dental technicians, and their association with job satisfaction, and (2) explore the factors associated with turnover intention among Taiwanese dental technicians.

Methods

Study design and participants

The Dental Technicians Association was not able to provide the member list due to the Personal Data Protection Act. A randomized sampling approach was impossible; therefore, two nonrandomized sampling approaches were adopted in this study. This cross-sectional study was first conducted on May 25, 2019, at the conference venue of the Taiwan Association of Dental Technology. When the attendees who visited the stall were confirmed by the researchers as licensed and practicing dental technicians, the researcher informed them of the study's purpose and the dental technicians who agreed to participate chose to complete the questionnaire on paper or online. This study did not provide rewards for participation; for improving their willingness to complete the questionnaire, we allowed the participants the choice of anonymity. A convenience sample was collected at the conference venue, and the link to the online survey was provided to the participants to invite individuals unable to attend the conference by the snowballing method. After the conference, there were further inquiries from potential volunteers about participation in the online survey; therefore, the online data was collected till September 21, 2019.

The online survey was set up in a way that the participants were required to type their email addresses, each email could only complete the questionnaire once to avoid duplicate responses, and any other possible duplicates were contacted via email. The inclusion criteria were dental technicians who had passed the national examination, with their current job in a dental laboratory, and were responsible for dental technology for at least one year. A total of 221 completed questionnaires were received on paper, and the remaining 127 were submitted online. After excluding the duplicates and respondents with seniority of < 1 year, 341 valid questionnaires were included in this study (217 papers and 124 online).

Ethical approval and consent to participate

The research protocol was approved by the Institutional Review Board of Kaohsiung Medical University Hospital (KMUIRB) (KMUHIRB-E[I]-20190094). All methods were carried out in accordance with relevant guidelines and regulations. The use of altered informed consent was approved by the ethics review board due to the anonymous and online nature of the study design.

Instruments

The structured questionnaire included demographic characteristics (such as sex, age, and education), working characteristics (such as geographical area of workplace, job position, working hours, salary, and seniority), experiences of DDT use (such as work content, job duties, types of DDT used, and number of DDTs learned), DDT acceptance, occupational burnout, job satisfaction, and turnover intention.

DDT acceptance

The DDT acceptance scale consisted of 13 items that were developed by the authors, based on literature review, and a few in-service dental technicians (Fig. 1). The scale included seven items related to the advantages of using DDT, three related to disadvantages, and three regarding future trends. The items were answered using a 5-point Likert scale ranging from 1 (strongly disagree) to 5 (strongly agree), and a sum score range of 13–65 indicated that DDT acceptance was obtained. Internal consistency for the scale in this sample was acceptable (Cronbach’s α = 0.77).

Fig. 1
figure 1

Attitudes of the participants toward DDT. #items regarding disadvantages, reverse scored when a sum is calculated. &items regarding future trends. The items without any symbol refer to advantages

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Occupational burnout

Occupational burnout was measured using the Occupational Burnout Inventory (OBI) developed by Yeh et al. [23]. The present study adopted the subscales related to personal burnout, work burnout, and over-commitment, each containing five items. The subscales of personal and work burnout were modified by Yeh et al. [23] from the Chinese version of the Copenhagen Burnout Inventory [24]. The over-commitment subscale was modified by Yeh et al. [23] from the Chinese version of the Effort-Reward Imbalance Model Questionnaire. The response scale ranged from 0 (never) to 4 (always), and the sum scores of each subscale were multiplied by 5; therefore, a full score ranging from 0 to 100 was obtained. The Cronbach’s α of the subscales ranged from 0.84 to 0.90.

Job satisfaction

Job satisfaction was measured using five items adopted in a study by Judge et al. [26]; those items were taken from the Brayfield-Rothe [25] measure of job satisfaction [25, 26]. The five items taken by Judge et al. [26] were as follows: “I feel fairly well satisfied with my present job”; “Most days I am enthusiastic about my work”; “Each day of work seems like it will never end” (reverse scored); “I find real enjoyment in my work”; and “I consider my job rather unpleasant” (reverse scored). The response scale ranged from 0 (strongly disagree) to 10 (strongly agree), and the sum score ranged from 0 to 50 [26]. In this study, the items were translated into Chinese by a bilingual translator, and the Cronbach’s α was 0.88.

Turnover intentions

Turnover intentions were measured as described by Blau and Lunz [27], and participants were asked to indicate their agreement with the following items: “I intend to leave the organization” and “I think about leaving the dental technician profession.” The items were rated on a four-point scale (1 = strongly disagree, 4 = strongly agree) [27].

Data analysis

All data were analyzed using the IBM Statistical Package for Social Sciences for Windows version 20.0 (SPSS Inc., Armonk, New York, USA). A significance level of 0.05 was used for all statistical analyses. Differences among sociodemographic characteristics, workplace characteristics, and DDT experiences in job satisfaction were assessed using an independent sample t-test or one-way analysis of variance (ANOVA) when the scores were normally distributed; similar comparisons in terms of turnover intentions were assessed using Chi-square test. The correlations between the DDT acceptance, burnout, job satisfaction, and turnover intentions were assessed using Pearson’s correlation coefficients. Stepwise multiple linear regression analysis was conducted to determine the predictors of job satisfaction among dental technicians. Regarding determinants of turnover intentions, the two items were divided into binary variables (agree or disagree) for further analysis using logistic regression models.

Results

Sample characteristics, working characteristics, and turnover intentions

In this study, most participants were male (n = 213, 63.6%) and most were aged between 20 and 29 years (n = 233, 68.5%); the mean age was 29.11 years (SD = 6.76). Most of the participants reported that their highest educational level was junior college (n = 201, 59.3%), followed by college or higher level (n = 117, 34.5%); most reported the geographical area of workplace to be Taichung (n = 97, 28.6%), followed by Taipei metro area (n = 93, 27.4%) and Kaohsiung (n = 86, 25.4%). Regarding work characteristics, most participants were employees (n = 315, 94.3%) who worked 40–59 h per week (n = 280, 83.6%). Most participants had work experience of < 10 years (n = 297, 87.1%), with a mean of 6.38 years (SD = 6.22), and an income of < 40,000 NT dollars per month (n = 275, 81.7%). Regarding turnover intentions, 71.7% (n = 241) of participants reported that they did not have the intention to leave the profession, and 67.1% (n = 226) reported that they disagreed with the intention to leave the organization (Table 1).

Table 1 Sample characteristics, work characteristics, and turnover intentions of the participants (n = 341)
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Work contents and DDT-related experiences

Regarding work contents, fixed partial dentures were the most frequent (61.3%), followed by removable dentures (32.6%), and digital fixed partial dentures (27.0%). Most participants reported that their job duties were CDT (70.4%), while others were responsible for DDT or both. CAD/CAM was the most popular DDT (62.8%), and only 85 participants (24.9%) reported that they had no experience in using any type of DDT (Table 2).

Table 2 Work contents and DDT-related experiences
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DDT acceptance, burnout, job satisfaction, and turnover intentions

Figure 1 shows the participant's responses to DDT acceptance. Overall, the participants were willing to learn DDT, had positive attitudes toward DDT efficiency, and negative attitudes toward cost and price. The average sum score of the DDT acceptance scale was 43.10 (SD = 5.958), ranging from 25 to 57. The average job satisfaction was 26.09 (SD = 7.617), ranging from 0 to 47. The average scores of personal burnout, work burnout, and over-commitment were 51.13 (SD = 21.628), 46.56 (SD = 21.550), and 39.41 (SD = 19.473), respectively, with scores ranging from 0 to 100.

The Pearson correlation matrix showed that DDT acceptance (r = 0.198, p < 0.001), personal burnout (r = − 0.595, p < 0.001), and work-related burnout (r = − 0.638, p < 0.001) were significantly correlated with job satisfaction (Table 6). Moreover, DDT acceptance (r = − 0.185, p = 0.001), personal burnout (r = 0.495, p < 0.001), work-related burnout (r = 0.531, p < 0.001), and job satisfaction (r = − 0.623, p < 0.001) were significantly correlated with the intention to leave the organization. Furthermore, DDT acceptance (r = − 0.226, p < 0.001), personal burnout (r = 0.390, p < 0.001), work-related burnout (r = 0.431, p < 0.001), over-commitment (r = 0.178, p = 0.001), and job satisfaction (r = − 0.468, p < 0.001) were significantly correlated with the intention to leave the profession.

Predictors of job satisfaction

An independent sample t-test revealed that sex (t = − 0.125, p = 0.901) and seniority (t = − 0.852, p = 0.395) had no significant effect on job satisfaction; however, employers showed a significantly higher job satisfaction than employees (t = 3.342, p = 0.001). One-way ANOVA showed that age group (F2, 334 = 0.049, p = 0.953), highest educational level (F2, 333 = 0.678, p = 0.508), income (F4, 329 = 0.982, p = 0.418), geographical area of workplace (F4, 331 = 1.064, p = 0.374), and job duties (F2, 335 = 1.678, p = 0.188) had no significant effect on job satisfaction; however, dental technicians with fewer working hours per week had higher job satisfaction (F3, 328 = 4.576, p = 0.004) (Table 7).

Significant univariate variables were further analyzed using stepwise multiple regression, which showed no collinearity among the variables (VIF = 3.867, CI = 18.889). The model revealed that higher work burnout decreased job satisfaction (β = − 0.650, p < 0.001), while higher DDT acceptance (β = 0.174, p < 0.001) and position as an employer (β = 0.147, p < 0.001) increased job satisfaction (Table 3).

Table 3 Predictors of job satisfaction among dental technicians
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Determinants of turnover intentions

With regard to the intent to leave the organization, the chi-square test revealed that only geographical area (χ2 = 10.358, p = 0.035) showed a significant difference; the other variables were non-significant (Table 8). Regarding the intention to leave the dental technician profession, highest educational level (χ2 = 9.334, p = 0.009) and geographical area of workplace (χ2 = 18.431, p = 0.001) showed significant differences, and the other variables were non-significant (Table 9).

Significant univariate variables were further analyzed to explore predictors of turnover intention based on the results of the binary logistic regression models (Tables 4 and 5). The results showed that geographical area of workplace had a variable effect on both types of turnover intention. Moreover, individuals with higher job satisfaction were negatively related to turnover intentions, whereas those who had higher work burnout were positively related to turnover intentions. Furthermore, participants with educational level of junior college showed lower intention to leave the profession (Table 5).

Table 4 Determinants of turnover intention among dental technicians—Intention to leave organization
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Table 5 Determinants of turnover intention among dental technicians—Intention to leave profession
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Discussion

Taiwan's dental medical division system commenced later than other developed countries, and the process of division of labor is controversial. Traditionally, the training of dental technicians is a Master-Apprentice system. Since the implementation of the "Physicians Act" in 1975 (which included dentists in the standard), some dental mold technicians are still engaged in medical practices such as filling or treatment, which formed the "secret doctor" controversy. The first official dental technology educational institution was established in 1981. After being questioned and opposed by dental physician groups at that time, and under the long-term wrestling and running-in of various interest groups, dental technicians were finally positioned as "not allowed to engage in any intraoral care work;" the "Dental Technicians Act" was passed in 2009, which included the management of dental technicians with different training backgrounds. The special historical context has caused today's dental technicians to be a relatively closed-off and self-protected group of professionals that are not easily referred by patients or the general public [28].

Today, the new generation of dental technicians in Taiwan are trained through the formal education channel, and school education has replaced the traditional Master-Apprentice system. Many participants in this study showed similar characteristics, such as graduation from junior college, younger age, lower seniority, and scarcity of employers, possibly because the participants were mostly graduates of formal dental technology training institutions and were attending seminars for continuing education credits. The results of the study also demonstrated that those with a professional degree had a lower intention to leave the profession than those with a high school vocational education (traditional Master-Apprentice system). Some traditional apprentice dental technicians were trained on-the-job for university degrees in non-dental fields (that is, oral hygiene), in order to qualify for the national examination. This might explain why university degrees did not have statistically significant influence on the analysis of the intention to leave the profession.

There were 2094 dental technicians and 1068 laboratories in Taiwan at the time of this study [10]. These numbers indicated that in addition to those employed by dental care institutions, many dental laboratories were solely run by the responsible person without any employees. In addition, the participants' reluctance to let their employers discover that they had assisted in inviting their colleagues to participate in this study might also be a reason for the small number of employers in this study sample. In the early days of Taiwan's dental technology industry, it was mostly family-run, Master-Apprentice system inheritance, and workshop-style. In the face of the reduction of patient visits and medical insurance costs, dental technicians adopted the business model of smaller profits and quicker turnover and coordinated with the dentists’ schedule, which often led to excessive working hours [29]. In this sample, 81.7% of participants reported a maximum monthly salary of 40,000 NT dollars, indicating that most earned a yearly income lower than the median of all employees and in the third decile of all health professionals in 2019 [30]. Further investigation focusing on the type of payment and its potential effects on dental technicians are encouraged.

In addition, most participants (95.5%) reported excessive weekly working hours, which was higher than most of the Organization for Economic Co-operation and Development countries in 2019 [31], as well as the average weekly working hours of health professionals in Taiwan [32]. Working overtime is an occupational health issue that has recently emerged in East Asian countries and has also attracted serious attention in Taiwan [33,34,35]. Long working hours have been found to adversely affect many risk factors of overwork-related diseases such as cardiovascular and cerebrovascular diseases [36]. The current study revealed that dental technicians are working overtime, highlighting the need for the development of policies or strategies to improve working conditions and prevent overwork-related diseases [35].

Similar to previous studies [2, 3], we observed that most participants agreed that DDTs increased the time efficiency and competitiveness of the digital workflow. However, fewer (33.8%) participants agreed that DDTs might increase their income, and more participants agreed that DDT tools and materials are expensive (Fig. 1). Although CDTs were reported as the main job duties, they only represented the current job scope. Young dental technicians frequently changed jobs, and in recent years, dental technology institutions and universities have incorporated digital dental technology into their curriculum. The digitalization of dental technology was found to be widespread in Taiwan, with most participants (75.1%) having learned at least one type of DDT; CAD/CAM was the most frequent type. Participants viewed DDT positively and accepted its advantages, which possibly improved their job satisfaction.

Compared to the norms of occupational burnout [23], dental technicians in this study showed higher personal and work burnout, along with lower over-commitment. Furthermore, their job satisfaction was moderate and lower than the high job satisfaction reported in a previous study among UK dental technicians [12]. Among Taiwanese dental technicians, 32.9% and 28.2% reported the intention to leave the organization and profession, respectively. The main predictors of turnover intentions in this study were identified as geographical area of workplace, work burnout, and job satisfaction; these results were consistent with those of previous studies in healthcare [18,19,20,21,22, 37]. The introduction of new machines such as CAD/CAM and oral scanners has led to automated production and shortened the working hours of technicians. In recent years, some dental technology institutions have shown a trend of medium-sized or large-scale development [28]. To the best of our knowledge, many participants in this study came from two large dental laboratories in Taoyuan and Taichung, which might explain the regional differences in turnover intentions presented in this study. Since some dental laboratories have begun to undertake overseas orders in recent years [28], globalization may increase cross-national business orders and change the business strategies of dental laboratories. Further studies related to the business model and organizational commitment are recommended [38, 39].

There are several limitations in this study. First, most participants were young, junior, and employees, and a potential sample bias could have existed. Second, owing to the adopted sampling and surveying method, this study could not calculate the response rate. Third, different collection method (hard-copy vs. online) may lead to different response quality. Fourth, the cross-sectional design could not lead to causal inference; the percentage of job position as employer was small, and it may have led to bias in multivariate analysis. Therefore, further investigations using randomized sampling to obtain more representative samples are warranted.

Conclusions

The present study revealed that most of the young dental technicians were working overtime with lower salary and had moderate job satisfaction. Several of them reported high burnout and turnover intentions. Although the DDT acceptance appeared to increased job satisfaction, the influence was limited. As Taiwan's dental care becomes increasingly specialized, it is crucial to maintain the concept of "teamwork" and retain good and professional dental technicians. Strategies for improving the work environment and occupational health of dental technicians should thus be the focus of future studies.