Isolation with rubber dam: Knowledge, training and attitudes of final year dental students

Background/Aim. Good undergraduate education is necessary to overcome the
 reluctance of dentists to use the rubber dam. The aim was to assess dental
 students' knowledge, training skills, attitudes, and opinions concerning the
 use of the rubber dam in order to isolate an operation field. Methods. A
 34-item original questionnaire was distributed to 130 final year students.
 The questions were divided into four segments: general information; rubber
 dam-related knowledge and training skills; opinions and attitudes regarding
 the use of rubber dam; opinions on the intended future use of rubber dam.
 Results. All students confirmed that they had theoretical lessons about
 rubber dam and that the advantages of the rubber dam were pointed out.
 During practical courses, 34% of students observed rubber dam placement and
 10% of them placed the rubber dam on their own or with assistance. Most of
 the students (88%) did not feel capable of using the rubber dam on their
 own. Less than half of the students (38%) believed that adequate isolation
 of the operating field is possible without the rubber dam. Sixty-four
 percent of students considered that rubber dam was not uncomfortable for the
 patients. More than half of the students were willing to use the rubber dam
 in their future practice. Almost all of them planned to gain additional
 postgraduate training. Conclusion. Students have solid theoretical knowledge
 about the rubber dam, they are aware of its importance and have a positive
 attitude towards the rubber dam use. However, their practical training and
 skills are poor and insufficient for independent rubber dam use.


Students Introduction
The use of the rubber dam is universally acknowledged as an ideal method for performing dental treatments completely free of saliva and represents the crucial element for achieving an absolutely dry operating field. [1][2][3] It also provides retraction and protection of the soft tissues, better visibility and aseptic conditions of the operating field, reduction of infectious pathogens in the aerosol, and prevention of aspiration or ingestion of instruments or irrigants. [4][5][6][7] Dental practitioners are encouraged and required to use rubber dam in their daily practice, as rubber dam is considered an essential factor that significantly influences the success and durability of dental treatments. [8][9][10] Despite scientific evidence and official recommendations, 11,12 dentists seem reluctant to use the rubber dam, as many recent studies report fairly low overall rate of rubber dam usage. [13][14][15][16] The most common reasons reported for its underuse were inconvenience and difficulty in use, insufficient and inadequate training, prolonged time of treatment, cost of equipment, as well as the assumption that patients would not accept it. 6,13,14,17 Interestingly, these obstacles were usually cited by dentists who did not use rubber dam regularly. 13,18 Among irregular rubber dam users, the factors found to influence the decision to use rubber dam included the type of treatment, material selection, and region of the mouth requiring treatment. Endodontic treatments are most frequently performed under rubber dam. 14,17,19 Regarding restorative treatments, the rubber dam was more often used for composite than for amalgam restorations, for treatment of posterior than of anterior teeth, and in the lower compared to the upper jaw. 14,17,19 Qualifying school 13 and graduate training intensity 20 also affect a rubber dam use. It was shown that recently graduated and younger dentists used the rubber dam more frequently than their older colleagues. 21 Also, there was a clear discrepancy in what dentists are taught in dental schools and in the way they practice after graduation in terms of rubber dam use. 16 Even final year dental students believed that their use of rubber dam would decrease once they have left school and began working in independent practice. 22 Previous 6 studies reported students' insufficient theoretical knowledge about the importance of rubber dam, 23,24 and possible negative perceptions associated with the rubber dam use. 22,25 There is a general agreement that acquiring knowledge and skills for the proper use of rubber dam should be a fundamental part of education in dental schools. Giving students a good theoretical background and allowing them to acquire manual dexterity during the studies should give them the confidence to use rubber dam in the future. To the best of the authors' knowledge, there are no scientific data on the prevalence of rubber dam use among Serbian dentists, nor are there data on whether and how rubber dam is taught in dental schools. Therefore, the purpose of the present study was to assess knowledge and training skills, as well as attitudes and opinions towards the use of rubber dam among the final, fifth-year dental students attending the School of Dental Medicine, University of Belgrade, Serbia. The study protocol for this observational cross-section study was approved by the Ethics Committee. Students were allowed to decline participation in the study. All completed questionnaires were collected anonymously. Descriptive analyses of the data gathered from the questionnaires were performed using the statistical program IBM SPSS for Mac (Version 21.0 Chicago, IL, USA).

Results
Of 130 questionnaires distributed, 108 were adequately completed and returned and were included in the study (response rate of 83.08%).

General Information
All students (100%) reported that they were attending all practical courses regularly.
Regarding theoretical classes, 44 of the students (41%) were regular attendants, while the rest of them (64 students, 59%) attended theoretical courses irregularly.

Knowledge and Practical Skills
All students that regularly attended theoretical courses (44 students) reported that they have been taught about rubber dam in classes and that the advantages of the rubber dam over relative isolation with cotton rolls and saliva ejectors were pointed out. Twenty-one of them (48%) considered that the topic has been covered in detail, 18 students (41%) reported that it was covered superficially, while 5 of them (11%) claimed that the topic was only mentioned. Figure 1 shows the distribution of responses regarding the subjects that had theoretical lessons about rubber dam that were obtained only from the students that regularly attended theoretical courses.
During practical courses, 37 students (34%) observed rubber dam placement, and 11 students (10%) placed the rubber dam on their own or with teacher's assistance. Nine students placed rubber dam only once, while two students placed rubber dam two times in different practical courses. In total, rubber dam has been placed 14 times -five times in restorative dentistry, five times in pediatric dentistry and four times in endodontics.
Ninety-five students (88%) answered that theoretical and practical training obtained during studies is not sufficient for them to use the rubber dam on their own. Half of them (56 students, 52%) have searched for more information about the rubber dam, mainly on the Internet.

Opinions and Attitudes
The overview of the responses to "yes/no" questions related to the students' opinion and attitude towards the use of the rubber dam is presented in Table 1.
The majority of students (55%) thought that rubber dam use would decrease the duration time of the treatment, while others thought it would increase (28%) or have no influence (17%) on the duration of the treatment. 8 When asked to express their opinion on the benefit of rubber dam use, 64% considered it beneficial for dental interventions in both upper and lower jaw, while the remaining students (36%) thought it was more beneficial for interventions in the lower jaw. Sixty-two percent of students agreed that it is equally important for the treatment of anterior and posterior teeth, whereas 38% thought it was more useful for posterior teeth. Half of the students (50%) reported that the rubber dam was useful for both composite and amalgam restorations, while 42% considered it useful only for composite restorations. Figure 2 shows the students' opinion about the most difficult step during the rubber dam application.

Opinions on the Intended Future Use
The majority of students (64%) reported that they were willing to use the rubber dam in their future practice and 27% would decide whether to use the rubber dam or not, depending on the type of the operative procedure or the situation they encounter (Figure 3), and 9% of the students did not plan to use it at all. Almost all of them (84%) planned to gain additional postgraduate training in different ways ( Figure 4).

Discussion
Although teaching students about the rubber dam has been part of dental school training for decades, there is worldwide scientific evidence showing its limited use among dental professionals. 13,14,20,[26][27][28] The most important measure proposed to overcome the reluctance of dentists to use the rubber dam is better undergraduate education and training. 15 Investigations among dental students, using questionnaires as a research instrument, are often conducted as a helpful tool to identify their knowledge and perceptions of the rubber dam, as well as to reveal potential problems in the educational process. [22][23][24][25]29 In the present study, all students that regularly attended theoretical courses confirmed that during lectures they have learned about the rubber dam and its advantages. Apart from restorative dentistry and endodontics, attention to rubber dam was given also in pediatric dentistry lessons, indicating the necessity of using the rubber dam in pediatric patients as 9 well. However, more than half of the participants have never observed or performed rubber dam placement during clinical training. This discrepancy between what is taught and how clinical procedures are being performed may be confusing for the future dentists.
Considering almost complete lack of practical training, it is not surprising that almost 90% of students did not believe that they were capable of using the rubber dam on their own.
All of the mentioned facts could explain the rubber dam underuse in independent practice after graduation from dental school.
Various results could be found in the literature with regards to the students' use of rubber dam on adult patients. In Saudi Arabia, dental students used rubber dam almost always, 29 while in Ireland and the UK the majority of students used rubber dam occasionally. 22 When it comes to pediatric patients, more consistent findings were reported -the rubber dam was used rarely or never. 22,25,29 Interestingly, in the present study almost equal number of students placed rubber dam during restorative dentistry, endodontics, and pediatric dentistry practical courses.
One of the segments that should be covered in dental schools is the legal aspect of rubber dam placement. In case when rubber dam isolation is not performed and an endodontic instrument is inhaled by the patient, a medicolegal aspect of negligence is impossible to defend. 30 Patient safety during dental treatment is essential from the practitioner's as well as the patient's point of view. Although it does not happen very often, there are some reports of inhalation and ingestion of endodontic instruments during root canal treatment performed without rubber dam isolation. 31,32 The present study shows that, despite little experience with the rubber dam, all students seemed to be certain about the necessity of acquiring knowledge and skills for rubber dam use during studies. They were convinced that rubber dam isolation has advantages compared to cotton rolls and saliva ejectors and that the success of endodontic treatment depends on rubber dam use. However, around 40% of students still believed that adequate isolation of the operating field for either restorative or endodontic procedures is possible without the use of the rubber dam. These results support earlier findings, but it should be noted that significant differences existed between the schools when more than one school was investigated. 22,23,25,29 Furthermore, various factors, such as clinical procedure, choice of material being placed, and the jaw in which treatment is performed, were found to influence the use of rubber dam. 14,17,19,22,25 In this study, more than half of the participants believed that rubber dam was beneficial for both upper and lower jaw, anterior and posterior teeth, and composite and amalgam restorations.
Considering that one of the frequent reasons mentioned for rubber dam underuse is its difficult application, around 70% of the students did not think it was a difficult and complicated procedure, nor that it was more difficult than other procedures they regularly perform. This is in contrast to the results of other studies, 22,23,25,29 probably because the students that participated in the present study observed the procedure, but did not perform rubber dam placement by themselves. Consequently, the vast majority of students were not sure concerning the most difficult step during rubber dam placement. The second most frequent response was clamp placement, similar to a previous study that reported clamp selection and its adaptation as the most complicated step for students. 25 Conversely, in another research, most students were confident regarding which clamp to use, but the most cited difficulty in rubber dam appliance was tight contacts. 23 Moreover, students had divided opinion on whether assistance was required for rubber dam placement. In another study students generally believed that assistance was not necessary for rubber dam application, 25 while Imbery et al. reported that students particularly struggled with rubber dam placement when they were working alone and that they preferred if the assistant was available. 24 It is students' 23,25,29 and dentists' 6,13,14,17 common belief that patients have negative attitude towards rubber dam. In the present study, around 65% of students considered that application of the rubber dam did not make dental procedures less comfortable for the patients, which is in line with the results reported by Mala et al. 22 When patients were asked, the majority of them had a positive experience with the rubber dam and preferred it to be used at their next appointment. [33][34][35] Rubber dam was acceptable even to pediatric dental patients. 36 The students involved in the present research were not particularly worried about the time needed for rubber dam application. Less than 30% of students thought that placing rubber dam would increase the time of treatment, which is opposite to the opinions of the students from another research. 25 It was proved that it takes only 4 to 5 minutes 23,33,34 for students to apply the rubber dam and even less time for the dentists. Probably, calculating the time that would subsequently be saved throughout the procedure performed with the rubber dam, most of the students in this research considered that the overall time of the procedure would be shorter.
The financial aspect, i.e. the fact that cost of the equipment and treatment cost increase, is one of the widely discussed factors that might influence the rubber dam use. 6,13,14,17 However, it is obvious that a technique with clear infection control has benefits, and medico-legal implications should not be excluded from use for reasons of cost. 14 This was confirmed by a study where no respondent referred to cost as a reason for not using the rubber dam. 17 While most of the students in this study thought that rubber dam purchase does not require significant financial resources, it could be assumed that finances would have a more significant impact on their attitude once they start working in the independent private practice.
Even though only a small number of students used rubber dam during their studies, the encouraging fact is that around 60% of them plan to use it regularly in their future work, suggesting their positive attitude and commitment to its use. As expected, 14,17,19 22,25 among those who intend to use rubber dam only for certain clinical procedures, endodontic treatment would be the one that, in their opinion, requires rubber dam application. Another anticipated situation that could potentially urge them to use the rubber dam is when it is difficult to maintain the operative filed dry with cotton rolls and saliva ejectors.
Nevertheless, final year dental students that participated in this study did not feel that they were sufficiently trained to use rubber dam on their own in the future, as almost all of them plan to gain additional postgraduate training, mainly through scientific meetings and workshops and from more experienced colleagues.
Based on the results of this study it could be concluded that students have solid theoretical knowledge about the rubber dam, they are aware of its importance and have a positive attitude and enthusiasm towards rubber dam use. On the other hand, their practical training and skills are poor and seem to be insufficient for independent rubber dam use. It is necessary to dedicate more attention to the rubber dam isolation technique throughout undergraduate practical courses so that after graduating dental students can implement acquired knowledge and skills in their practice. To avoid confusion among students, teachers in dental schools should be consistent and eliminate the discrepancy between how they perform dental procedures in the clinic and what they teach in the classroom.