Evaluation of Attitude and Knowledge of Endodontic, Pedodontic and SBARD Residents in Saudi Arabia toward Regenerative Endodontics—A National Survey

Background and Objectives: There are no guidelines on the regenerative endodontic procedures that should be followed in dental treatment. Thus, it is essential to learn the knowledge, attitudes, and opinions about regenerative endodontics among dental practitioners, particularly endodontists, as they are the first providers of this type of dental treatment. Aim: This study aimed to assess the knowledge and attitudes among residents of the Saudi Board of Advanced Restorative Dentistry (SBARD) in Saudi Arabia. Methods & Materials: A questionnaire-based survey was conducted among 128 residents of endodontics, pedodontics, and the SBARD in Saudi Arabia. The questionnaire was distributed to participants using the available electronic measures such as emails and social media. The questionnaire was made by Google Forms, and responses were received directly in the excel sheet in the email. The data were exported as an excel file, coded, and analyzed, and the p-value < 0.05 was set as significant. Results: More than 50% (74 dentists) of the participants reported receiving continuing education in regenerative treatment, with a significant difference found among specialty (p = 0.023). No significant association was found between knowledge, gender, and type of postgraduate study. The vast majority (89.1%) of the participants believed regenerative endodontics should be incorporated into dentistry curricula. About two-thirds (78.2%) of the participants declared their ability to attend future training courses in a regenerative endodontic, whereas 10.9% did not, and 10.9% were unsure. Conclusions: The dental practitioners were enthusiastic and interested in regenerative and stem cell treatment. The results also suggested incorporating regenerative treatment into the dental curriculum and signaled the need for more continued training courses.


Introduction
Regenerative endodontics refers to creating and delivering a newly formed pulp to replace the diseased, missing, or traumatized pulp and surrounding structures with live tissue from the same origin [1]. Different regenerative endodontics procedures have been identified, such as revascularization, apexification, direct pulp capping, partial pulpotomy, apexogenesis, tissue engineering, and stem cell therapy. Several factors can affect successful treatment with regenerative endodontics. Some of these factors are: (i) disinfection of the canal to achieve a clean environment, (ii) apex diameter, and (iii) the patient's age [2]. Different types of medications and solutions are available as disinfectants. Apex diameter is another factor in the success of regenerative endodontic treatment. An open apex will allow the formation of new tissue by the migration of stem cells into the root canals.
A recent systematic review showed that the influence of the patient's age on the prognosis of vital pulp therapies (VPT) remains unclear [3]. Several of the reviewed studies included only young patients ranging from 9 to 17 years of age, up to 35 years, reflecting the rationale that the pulp of young patients possesses a higher capacity for recovery. Nevertheless, other studies involving a more comprehensive range of ages from 9 to 69 years did not report an impact of the patient's age on the outcome of VPT [3]. Revascularization/revitalization techniques aim to increase the length and thickness of the root while maintaining important pulpal characteristics. A tooth that has been successfully revascularized would not require extra treatment [4][5][6][7][8]. Additionally, regenerative endodontic procedures should not be performed on deciduous teeth because of the possibility of impairing the eruption of permanent teeth. Few studies stated some clinical considerations about regenerative endodontics, and no clear guidelines have been developed [9,10]. However, the European Society of Endodontology's (ESE) Position Statement on Revitalization Procedures and Clinical Considerations for a Regenerative Procedure, both of which were adopted from the American Association of Endodontists (AAE), are available. Such guidelines regarding regenerative endodontic procedures' ethical use and boundaries are essential for dentists, researchers, and the general population [11]. As a result, it is critical to understand dental practitioners' knowledge and attitudes about regenerative endodontics, particularly endodontists, who are the first to administer this type of dental treatment [12][13][14][15][16][17].
Endodontics is particularly concerned about advances in endodontic techniques and pedodontics that routinely deal with deciduous teeth where regenerative treatment is contraindicated. The residents of the Saudi board are postgraduate students who should be aware of new technologies developed in dentistry. Few studies have been conducted in this regard, and no study has been conducted in Saudi Arabia. This study aimed to assess the knowledge and attitudes among residents of the Saudi Board of Advanced Restorative Dentistry (SBARD) in Saudi Arabia.

Setting
This study obtained ethical approval from the ethics committee of the Faculty of Dentistry, Najran University, with an ethical approval code (2020/02/0049), 18 May 2020. This questionnaire-based survey was conducted among 128 residents of endodontics, pedodontics, and the SBARD in Saudi Arabia. The data were collected from June to October 2020 with a closed-ended electronic questionnaire to solve the questions of this study. The questionnaire was adopted from previous studies [18][19][20], and no changes have been made to the questions.

Sample Size Determination
The sample size calculation was determined using GPower software (version 3.1) Franz Faul, Universitat Kiel, (Kiel, Germany), using the x 2 test, to determine that an appropriate sample size for the current study objective would be confirmed with a small to medium effect of size 0.3. Further comparison would be detected reliably, employing the goodness-of-fit test as a statistical test, and an, A priori type of power analysis: compute the required sample size given α, power and effect size with a conventional alpha level of 0.05, and a degree of freedom of 3 with 0.82 power. The obtained sample size was 127 participants.

Questionnaire
The questionnaire consisted of four parts; the first part consisted of questions related to characteristics of the participants, including gender, specialty, type of postgraduate study, level of training, location of postgraduate study, and practice hours per week. The postgraduate studies were of two types, either SBARD residents or master's students, and the level of training was divided into four levels. Master's degree students had only level I (R1) and level II (R2) training, whereas SBARD residents had four levels of training, from level I (R1) to level IV (R4) training. The second part of the questionnaire consisted of six questions relating to the participants' knowledge about regenerative endodontics. The third part consisted of 10 questions relating to the participants' attitudes toward some issues regarding treatment with regenerative endodontics. The final part consisted of four questions relating to the participants' agreeability toward practicing and recommending dental treatment with regenerative endodontics. The other three questions were about the possibility of facing cases in clinical practices for which regenerative treatment is indicated.

Administration of the Questionnaire
The electronic questionnaire was distributed to participants using electronic measures such as emails and social media. Responses to questions were received via the website where the questionnaire was created (Google Scholar). The inclusion criteria included Saudi dentists who were SBARD residents or master's degree holders in endodontics or pedodontics. The summary of the study aims and a protection of privacy was provided at the beginning of the questionnaire, and the respondents were to click a button of acceptance to participate in the study.

Statistical Analysis
The data were exported as an excel file, coded, and analyzed using the SPSS software program version 25 IBM, Stanford University (California, USA). A p-value < 0.05 was set as significant. The statistical test used was Pearson's chi-square used for contingency tables.

Characteristics of the Sample
There were 128 complete responses received from study participants, and the majority (62.5%) were males. Of the participants, 35.9% were residents of the endodontic department, 35.9% of participants were residents of the pedodontic department, and 28.1% of participants were residents of the SBARD. Most postgraduate students were board graduates, totaling 110 participants (85.9%), and 18 (14.1%) had master's degrees. About a third of the participants (32%) were in R4 (level 4) of the training, and a slightly lesser number were in R3 (level 3), followed by the number of residents in R2 (level 2) and R1 (level 1). About half of the participants (51.6%) studied in the central region, followed by 32.8% in the western region and only 3.1% in the northern region. Regarding the practiced hours per week, most participants (74.2%) claimed that they practiced more than 20 h per week, whereas 25.8% reported less than 20 h per week. More details about the characteristics of the sample are presented in Table 1.

Knowledge
More than 50% of the participants reported that they had received continuing education in regenerative treatment, with a significant difference by specialty (p = 0.023), whereas no significant difference was found according to gender and type of postgraduate study. The majority of participants (86.7%) reported that they had never used umbilical cord or any other type of stem cells, with no significant difference according to the study variables (gender, specialty, type of postgraduate study). About one-third of the participants (38.3%) reported using some regenerative endodontic procedures in their dental practice, and 61.7% reported not using any. There was a significant difference according to specialty (p = 0.006), but no significant difference was found according to gender and type of postgraduate study. Half of the participants reported positively to the question related to the healing of non-surgical or root canal treatment, whereas 9.4% had negative answers, and 39.8% did not know. Significant differences in responses were seen according to specialty, with a p value < 0.05. Similarly, half of the participants chose "all of the above" for the most valuable regenerative treatment options, with no differences between the study variables. For the optimal treatment of necrotic immature teeth, significant differences were found between the participants according to specialty and type of postgraduate study, but there was no significant difference according to gender (Table 2). The vast majority (89.1%) of the participants believed that regenerative endodontics should be incorporated into dentistry. No significant differences were found according to the study variables. About 65% of participants thought positively that a stem cell bank would be helpful, with significant differences according to specialty (p = 0.007). Nearly half of the participants (51.6%) thought that it will take 0 to 10 years for stem cells to be used in dentistry. A significant difference was also seen according to specialty (p = 0.007). One-third of participants thought that dentists need 11 to 20 years to implant new teeth using the regenerative stem cell method. Additionally, a significant difference was found according to specialty (p = 0.002). Most residents (61.7%) reported that higher cost was the biggest obstacle to patients accepting stem cell and regenerative treatment. There was a significant difference in gender concerning this question (p = 0.020). More than half of the participants (58.6%) believed that regenerative treatment would be better than an implant, 35.9% were unsure, and 5.5% reported that it would not be better. A significant difference was found according to specialty (p = 0.042). Most residents (89.1%) reported that regenerative endodontic procedures should be tested on animals before clinical application to patients. There were no significant differences according to the study variables. When the residents were asked about their assessment of regenerative treatment, about half (52.3%) reported that they did not know whether the treatment would be successful, 43% reported that the treatment would be successful, and 4.7% chose that it would be unsuccessful. A significant difference was found according to gender (p = 0.001) and specialty (p < 0.001). No significant differences were found between participants when asked if professional associations should regulate the use of regenerative endodontic treatment and stem cells. More than 45% of participants believed that the cost of regenerative treatment should be more than the current conventional treatment, 23.4% thought it should be the same, and 7.8% thought that it should be less. A significant difference was found according to specialty (p = 0.026) ( Table 3).

Attitude
About two thirds (78.2%) of the participants were willing to attend future training courses in regenerative endodontics, 10.9% were not, and 10.9 were unsure. No significant differences were found according to the study variables. Similarly, no significant differences were found between the participants concerning saving teeth and dental tissue for future use in regenerative endodontic treatment, but a significant difference (p = 0.005) was found according to gender concerning collecting dental tissues for a stem cell bank. Concerning the reason that would make the residents recommend regenerative treatment for their patients, half of the participants reported that they would recommend regenerative treatment if it was the most effective treatment, one-third (33.6%) of participants would recommend it if it was safe and reliable, 11.7% would recommend it if it was the most cost-effective, and 2.3% reported that they would never recommend regenerative treatment for their patients. No significant differences were found among all the study variables (Table 4).

Discussion
Regenerative treatment in dentistry has opened the door toward saving vitality and thus extending the lifetime of teeth. Learning the knowledge, opinions, and attitudes of dentists (general practitioners or specialists) is a significant key factor for further guidelines and recommendations regarding regenerative treatment in daily dental practice [11,12]. Endodontists and pedodontists seem to be the first practitioners who would deal with such treatment. This survey aimed to investigate the knowledge and attitudes regarding regenerative endodontic procedures among dental specialists who are most involved in endodontic treatment. This is the first study in Saudi Arabia regarding this issue, to the best of our knowledge.
Most of the participants were on the Board for postgraduate specialty. This may relate to the fact that this type of postgraduate study is preferred in the Saudi dental society, although it is more complicated than a master's degree or an advanced restorative board. The location of graduation was more frequently in central and western regions, which may correlate to the distribution of graduate educational centers. About two-thirds of participants reported more than 20 h per week of practice. This is consistent with the type of postgraduate study in which practice and rotation shifts are more demanding than in master's or in board studies. More than half of the participants had taken a continuing education course in regenerative treatment. This result is close to that found by Utneja et al. [20], in which 50.6% of the Indian participants had continuing education. However, this percentage of the current study is higher than that reported by Ez-Abadi et al. [21] and Shah et al. [22], who reported 24.8% and 37% continuing education among Iranian and another group of Indian participants, respectively. These results might be due to the higher availability and accessibility of continuing education in Saudi Arabia than in the other countries. Using the umbilical cord or other types of stem cells was found among 13.3% of participants. This result is similar to that found in a survey conducted in the USA by Epelman et al. [23] in 2009, but it is lower than the results found among the Iranian sample in 2017 [20]. Using some regenerative treatment in dental practice was reported by only 38.3% of participants, with the bulk of these using membranes, scaffolds, or bioactive materials. This result is close to that reported by Ez-Abadi et al. [21] and Deborah et al. [24], but lower than that reported by Epelman et al. [23] and Shah et al. [22]. The majority (65%) of the endodontics and pedodontics SBARD and residents were unaware of prior regenerative endodontic procedures but concerned about their outcomes. According to half of the participants, the regenerative endodontic procedure might be employed in various applications, including peri-radicular bone repair, ongoing root growth in immature teeth, pulp tissue rejuvenation during a root canal, and tooth re-implantation. Similar results were seen in a study conducted among Indian populations [24]. The majority of participants (49%) considered tribiotic paste the optimal treatment for necrotic immature teeth. This is in agreement with a study conducted among south African populations [25]. The administration of calcium hydroxide, followed by MTA apical plugs and backfilling with obturation material, is considered the best treatment for necrotic immature teeth by 17.2% of the participants. This reveals that the residents are untrained in sophisticated regenerative endodontic methods. There is a need for continued training and continuing education programs, from the simplest blood clot revascularization method to the most complex treatment, which involves creating tissue-engineered dental pulp constructs in the laboratory and implanting them into cleaned and shaped root canals related to all treatments that accomplish pulp-dentin regeneration.
Most participants thought regenerative treatment should be incorporated into the undergraduate curriculum and dental education. This is similar to the previous study, suggesting the need to review the current curriculum and include new technologies and methods in learning and practicing [20]. The higher cost of regenerative treatment and stem cells was the biggest obstacle to patients accepting such treatment, as reported by 61.7% of participants, higher than the findings reported by Chitroda et al. [26] and Epelman et al. [23]. The higher cost of such treatment might be due to the more expensive types of equipment and the hard work needed. With the progress of new technology, this cost may decrease significantly. Most of the significant differences between participants' responses were found concerning their specialty. This may relate to the different quantity of study material in Board and master's programs, or it might be due to the difference in number from each type. A high percentage of knowledge about regenerative treatment and stem cells may be partially due to the media, hearing about it from friends, or reading about it in academic journals.
On the other hand, this reflects the participants' positive attitude toward attending continuing courses about regenerative treatment and their willingness to save teeth and dental tissue for stem cell banks. Further research may be conducted to evaluate the dental practitioner's understanding of the numerous methods, changes, and newer materials available for regenerative endodontic operations. A survey of endodontics and pedodontics residents and instructors in various geographic regions would aid in the development of a better understanding of worldwide knowledge and attitude regarding regenerative endodontics.

Limitations
Some limitations should be noted in the current study, however. First, electronic-based research relied on readily available electronic measurements, potentially reducing the number of participants. Second, no details about the educational center were taken that would reflect differences in curricula and educational methods. The third limitation is the respondent's bias. Further studies are recommended among larger samples from different educational centers.

Conclusions
We conclude that most of the participants had good knowledge and awareness regarding regenerative endodontics, and their attitude was positive toward applying this technique in dentistry. Most of the participants agreed with the importance of including educational material about regenerative endodontics in the curriculum. A significant difference in the level of knowledge was found among different specialties. Institutional Review Board Statement: The study was conducted in accordance with the Declaration of Helsinki and approved by the ethical committee of the College of Dentistry, Najran University, with an ethical approval number 2020/02/0049, 18 May 2020.
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study. Written informed consent has been obtained from the participants to publish this paper.
Data Availability Statement: Any data used in the current article can be provided upon request from the corresponding author.