Use of contemporary technologies and new materials in undergraduate Endodontics teaching

Background This study aims to analyze the use of contemporary technologies and materials in undergraduate endodontic teaching in Spain. Material and Methods The survey was sent to the undergraduate endodontic programme leads in the 23 Spanish dental schools. The survey asked about the use of magnification, ultrasonic devices, electronic apex locator, rotary instruments, root-filling techniques, and bioceramic cements in the teaching of endodontics. Results The response rate was 91%, and the final number of schools included in the study was twenty. Only two schools (10%) used magnification (loupes or operative microscope). Five schools (25%) used ultrasonic devices to prepare the access cavity, and four (20%) to activate the irrigation solution. In 14 dental schools (70%) no type of ultrasonic instrument was used. Electronic apex locators in working length determination was used in 19 schools (95%). All schools used rotary instrumentation in the teaching of endodontics, and 45% of schools used reciprocating instruments. Five schools (25%) used warm vertical compaction technique, four (20%) single cone gutta-percha technique, and four (20%) thermoplastic injection techniques. No school used carrier-based gutta-percha. Bioceramic cements were used in 19 of the schools (95%). Conclusions Spanish dental schools have incorporated some of the new endodontic technologies and materials, including the electronic apex locator, rotary instruments, and the new bioceramic cements; however, the modern root filling techniques, magnification, and ultrasonic instruments are not yet used in most dental schools. Key words:Bioceramic materials, dental schools, endodontic curriculum, magnification, online survey, rotary instrumentation, ultrasonic devices.


Introduction
Graduate in dental schools must acquire the knowledge and skills necessary to perform endodontic procedures with an adequate level of competence (1). Technical standards of endodontic treatment are associated with quality and quantity of undergraduate education in Endodontology (2,3). For this reason, it is very important that new technologies and new materials are incorporated into undergraduate teaching of endodontics. Only in this way will it be guaranteed that the graduate has the necessary skills to be able to perform endodontic treatments complying with the required standards. The European Society of Endodontology (1) and the Association for Dental Education (4,5) recommended the use of contemporary technologies and new materials in endodontic undergraduate teaching. The incorporation into endodontic clinical practice of electronic apex locators, ultrasound, rotary instruments, magnification and continuous heat wave obturation techniques, and new bioceramic materials, has led to a substantial improvement in endodontic technique, better treatment outcomes, and greater comfort for the endodontist and patients. In Spain, the endodontic teaching in each one of the 23 existing dental schools, 12 in public universities and 11 Conclusions: Spanish dental schools have incorporated some of the new endodontic technologies and materials, including the electronic apex locator, rotary instruments, and the new bioceramic cements; however, the modern root filling techniques, magnification, and ultrasonic instruments are not yet used in most dental schools.  in private universities, is carried out according to the curriculum approved by the University and supervised by the National Agency for Quality Assessment and Accreditation (ANECA). However, there is no data on actual use of contemporary techniques and new endodontic materials in Spanish dental schools. The objective of this study was to analyze by means of a survey, the current use of contemporary technologies and new materials in the undergraduate endodontic teaching in Spain.

Material and Methods
An online survey was used, including multiple-choice questions, with more than one answer selected when appropriate. The topics included in the questions were the following (Table 1): 1) Use of magnification, 2) Use of ultrasonic instruments, 3) Use of electronic apex locators, 4) Use of rotary systems in root canal instrumentation, 5) Use of filling techniques, other than lateral compaction, for root canal filling, and 6) Use of advanced endodontic materials such as MTA or Biodentine. The contact details of the professors in charge of teaching endodontics in each dental school were obtained online, from school web pages, and through personal contacts. All the undergraduate endodontic program lea-e385 ders were sent an email explaining the objective of the study, together with a link to answer the survey through Google. The survey opened on December 23, 2019, the same day the first email with the link was sent. A reminder email was sent 1 week after initial contact. The data was obtained directly from Google, which generated it maintaining anonymity. Using the Excel program, simple descriptive statistics were generated for each item in the survey.

Results
Of the 23 dental schools that were asked to collaborate in the study, 21 responded to the survey (91.3%). Given that one of the schools was excluded because it had not completed its dental degree studies and was not yet teaching endodontics, the final number of schools that were included in the study was twenty. Respect the use of magnification in pre-clinical and clinical endodontic training (Q1) ( Table 2), no type of magnification was used in 18 schools (90%), using loupes and operative microscope in 2 of the schools (10%). The second question (Q2) referred to the use of ultrasound devices during preclinical and clinical practices. In 70% of the schools (n = 14), no type of ultrasonic instrument was used. However, in 5 of the schools (25%) ultrasound was used to prepare the access cavity, and in 4 (20%) to activate the irrigation solution. Only 1 of the schools used ultrasonic in root canal instrumentation.
The use of electronic apex locators in working length determination was the target of the third question (Q3). Nineteen of the schools (95%) used both the radiographic technique and electronic apex locator in working The questions raised in the present study are based on the survey previously conducted in the UK (11). Taking into account the response rate (91%), similar to that obtained in other surveys conducted in Europe (7)(8)(9), the data provided by the present survey are consistent. Learning endodontic treatment is essential in endodontic training. That is why the largest percentage of time in endodontic studies is dedicated to root canal treatment (11). Determining the working length is a very important phase of root canal treatment, and the electronic apex locator has been widely introduced into everyday clinical practice. The use of electronic apex locators in working length determination is the gold standard technique. The results of the present survey show that, as in the UK (11), electronic apex locators are used in working length determination in all Spanish dental schools. However, other modern technologies do not appear to have yet been fully incorporated into endodontic teaching. So it is with magnification. Survey results show that only 10% of dental schools use magnification in the practical teaching of endodontics. By contrast, in the UK 80% of dental schools have incorporated the use of magnification (11). A possible explanation for the delay in incorporating magnification into endodontic teaching could be the high economic cost of operating microscopes and the lack of staff training (12). Another of the new technologies that seems not to have been incorporated into the teaching of endodontics, at the undergraduate level, is ultrasonic devices. Currently, the use of ultrasound is widely introduced in the endodontic clinic for the preparation of the access cavity and the agitation of the irrigating solution during root canal e387 instrumentation. Nevertheless, almost three quarters (70%) of Spanish dental schools do not use ultrasonic instruments in the teaching of endodontics. Only 25% of schools use ultrasonic instruments in endodontic training to prepare the access cavity, and 20% in irrigant solution agitation. In contrast, data from the survey conducted in the UK show that ultrasonic instruments are employed in 53% of schools for access cavity preparation, and in 80% of schools for different procedures during clinical practices (11). Regarding root canal filling, the results show that cold lateral compaction is, still today, the root-filling technique taught in all Spanish dental schools. On the contrary, cold lateral compaction was used exclusively in 47% of the dental schools in the UK (11). Few dental schools use the warm vertical compaction technique (25%), the thermoplastic injection technique (25%) or the single cone gutta-percha technique (20%). These three techniques are used in the UK by 33%, 13%, and 27% of the schools, respectively (11). It is striking that despite the enormous commercial support for carrier-based gutta-percha systems, none of the Spanish dental schools use it. In contrast, in the UK 27% of schools used carrier-based gutta-percha systems in endodontic teaching (11). The responses to the last question in the survey demonstrate that the use of calcium silicate endodontic cements is fully incorporated into undergraduate endodontic clinical training in Spain. Majority of English dental schools also are teaching and recommending the application of calcium silicate cements (11). Of the six new technologies and materials analyzed in this survey, modern root filling techniques, magnification and ultrasonic instruments are not being adequately taught in Spanish dental schools. Undoubtedly, one of the reasons may be the high cost that these three new technologies and materials entail. In fact, most of the dental schools that did include these technologies in undergraduate endodontic teaching were private universities.
Another reason that could explain the little incorporation of some modern technologies to the teaching of endodontics in Spanish dental schools, could be the training of the teachers who teach endodontics, as well as the motivation and interest they have (13). The teaching of endodontics should be supervised by instructors with specialized training in endodontics (1). In the first survey conducted in the UK in 1997, none of the schools had supervising staff with advanced training in endodontics (6). However, in the recent survey carried out in the UK (11), most of dental schools employed general dental practitioners with special interest in endodontics, endodontists or a combination of both for endodontics teaching. The specialty of endodontics is not recognized in Spain, so the professors who teach in dental schools are general dental practitioners with a special interest in endodontics.

Conclusions
Spanish dental schools have incorporated some of the new endodontic technologies and materials, including the electronic apex locator, rotary instruments, and the new bioceramic cements; however, the modern root filling techniques, magnification, and ultrasonic instruments are not yet used in most dental schools.