Patients who need endodontic treatment are often burdened by two main concerns, the length of the procedure and pain (1). Endodontic treatment is often accompanied by negative connotations caused by the patient's unfounded perceptions. Many patients who have not experienced endodontic treatment would rather undergo a tooth extraction, however, of the patients who actually underwent endodontic treatment, only 17% described it as an extremely painful experience, and 96.3% agreed to the re-intervention (2, 3). The behaviour that is shaped by painful experience can be conditioned and unconditioned. Acute pain is an example of unconditioned behaviour, where the appearance of triggers causes a pain response, and the patient's reaction is not under the influence of environment. Chronic pain, because of its duration, increases the level of anxiety resulting in a conditioned behaviour (1).
Anxiety is a condition that manifests itself in excess difficulty and a sense of fear advancing to panic, accompanied by the psychomotor agitation and inner discomfort (4, 5). Etiological theories explain the emergence of phobic anxiety disorders with the process of imprinting emotional reactions in the critical period of maturation which is why there are difficulties to change them later (6). Dental anxiety is caused by a specific stressful situation in a dental office. Fear usually begins after traumatic experiences in childhood or by adopting phobic behaviour learned from parents (6, 7). Anxiety can be caused by the expectation of a threatening situation, perception of which involves the cognitive processes. One of the parameters that have a major impact on the cognitive processes is fear of dental pain, and also knowledge, feelings, and beliefs (3).
Dental fear is a reaction to a known danger because it occurs in people who have already had a number of negative dental experiences and who expect the bad experience to be repeated. The most intense form of the fear of dentist is dental phobia (4, 8).
Anxious patients are prone to seek treatment only in case of existing pain probably caused by the severe stage of the disease. Therefore, the anxious state of the patient in dental practice is intensified (9).
Psychological characteristics of people and the potentially negative experience overpower the objective state of the patient regarding the procedure (10). This creates a vicious circle of anxiety and pain, with a tendency of the two to increase (2, 3).
Pain which is present during dental procedures is, among other things, related to the emotional state of the patient. Other factors that influence the experience of pain are age, gender, oral health, frequency of dental visits, socio-economic status and the dentists’ way of dealing with the patient (11).
After determining the cause of pain and anxiety, it is up to the dentist to find the optimal way to control pain. This is achieved by a physiological and pharmacological approach and a combination of both (14).
Pain control is dependent on the identification of psychological needs, knowledge and skills for the proper conduction of dental surgery and postoperative care of the patient (1).
The purpose of this study was to compare the level of anxiety reported by patients and assessed by dentists. Also, the expected and actual pain during the treatment perceived by the patient and dentist were assessed. This could reveal some factors associated with exaggerated perception of pain in patients undergoing endodontic therapy.
SUBJECTS AND METHODS
The study was conducted in the Department of Endodontics and Restorative Dentistry, School of Dental Medicine, University of Zagreb, at Community Health Centre Zagreb-Centre (Runjaninova 4, 10000 Zagreb, Croatia).
Respondents, endodontic patients and therapists were informed in detail of the nature and course of the study, and they signed informed consent forms. The study was approved by the Ethics Committee of the School of Dental Medicine in Zagreb on 23rd of May 2013.
Subjects were approached in the waiting room where they completed the first part of the questionnaire. Of the total of 86 patients who were contacted, three of them refused to participate, and 17 questionnaires had to be excluded due to the incomplete information. The statistical analysis included 66 questionnaires.
The questionnaire was modelled on Corah’s Dental Anxiety Scale (CDAS), published in 1969, which proved to be a valuable and reliable indicator in clinical trials (5, 15). It was distributed to 30 students of the School of Dental Medicine for validation. The questionnaire consisted of two parts and was filled out before and after endodontic procedures. One part was intended for dentists and the other for patients.
The questionnaire for the patients before endodontic procedures contained questions on demographics (gender, age), the frequency of dental visits, the level of anxiety and expectations about the level of pain. The questionnaire for the patient after endodontic procedures evaluated the level of pain experienced by the patient and the patient's assessment of empathy of the dentist during the treatment.
The questionnaire for the dentist before endodontic procedures contained information on gender, years of work in the dental practice, type of practice (health centre, private clinic or public dental office), education level (dentist, resident, resident or student). Dentists estimated the level of anxiety and the expected severity and the intensity of pain. The diagnosis was recorded for each patient (acute pulpitis, chronic pulpitis, acute apical periodontitis, chronic apical periodontitis, pulp necrosis, healthy pulp, etc.). After the endodontic treatment, the dentists reassessed the intensity and severity of the pain felt by the patient during surgery. The type of anaesthesia was recorded as well (intraligament, plexus, mandibular).
Statistical analysis of data
The level of significance was set at p <0.05, and all confidence intervals were given at the level of 95%. In all cases, two-tail tests of statistical significance were used. Exact Test and Monte Carlo Test of statistical significance were used. Normality of distribution was checked with the Shapiro-Wilks Test in the case of a sample of less than 30 or Kolmogorov-Smirnov test in the case of sample size larger than 30. As a measure of central tendency, the median and interquartile range in case of deviation from the normal distribution were used, or the mean and standard deviation for greater precision and sensitivity scale of 0-10. To test the difference between two independent groups for continuous numeric variables, such as differences in the intensity of pain in relation to gender, the Mann-Whitney U Test was used. To test the difference between more than two groups for continuous variables, such as differences in the intensity of pain with regard to diagnosis, the Kruskal-Wallis Test was used. When analysing the difference between the two dependent groups on continuous variables, such as differences in the expected intensity of pain and actual experienced pain, the t-test for paired samples was used. Correlation between two numerical variables was analysed using Spearman's Rho correlation coefficient. All statistical analyses were performed in SPSS 17.0 (SPSS Inc ., Chicago, IL, USA) .
Description of the sample of patients
Distribution of the sample by gender, age and frequency of dental visits is shown in Table 1.
Classifying patients according to diagnosis and type of anaesthesia
According to the diagnosis, 13 (19.7%) patients had acute pulpitis, 8 (12.1%) chronic pulpitis, 2 (3.0%), acute apical periodontitis, 15 (22.7%), chronic apical periodontitis, 17 (25.8) pulp necrosis, and 11 (16.7%) patients had other diagnoses.
According to the type of anaesthesia given, 18 (27.3%) of patients received plexus anaesthesia, 2 of them (3.0%) intraligamentary and 2 (3.0%) block anaesthesia. In the majority of patients, 44 (66.7%), the procedure was performed without anaesthesia.
Number of dentists by gender, length of practice, type of practice in which the procedure was performed and the level of academic education
With regard to gender, 21 (32.3%) dentists were male, and 44 (67.7%) female. The average length of practice was 3 years, which is connected with the fact that the procedures were performed by students in the highest percentage - 52 (78.8%). Others were performed by general dentists - 9 (13.6%), residents - 3 (4.5%), one by an intern and one by a professor.
Dental Anxiety Scale
Original results of this study, according to dental anxiety scale are shown in Table 2.
The difference in the intensity of pain during the procedure with regard to gender of patient and dentist, diagnosis, type of anaesthesia given, previous pain, frequency of dental visits
There was no statistically significant difference in the intensity of pain during the procedure with regard to gender, diagnosis, anaesthesia, pain experienced earlier, the frequency of dental visits and gender of dentists. Also, there was no statistically significant correlation between the intensity of pain with patient’s age (Spearman Rho = -0.172, P = 0.172), as well as the length of dentist’s practice (Spearman Rho = 0.123, P = 0.324).
Correlation of patient’s pain with dentist's behaviour
There was no statistically significant difference in the intensity of pain with regard to behaviour of dentists towards patients.
There was a statistically significant correlation between patients' assessments of dentist’s tenderness and estimated intensity of pain during the procedure (Spearman Rho = -0.500, P <0.001). The correlation is negative, which indicates that when the patient’s assessment of dentist’s tenderness is higher, the estimated intensity of pain is lower.
Expected and actual pain
There were significant differences in the intensity of expected pain and the actual pain during the procedure (t-test = 3.540, P = 0.001). Patients’ expectations of pain intensity were higher than the intensity of actual pain they felt during the procedure.
There was no statistically significant difference in the expected intensity of the pain and the actual intensity with regard to patient's gender, patient's age, the frequency of dental visits, the pain in the past week, gender of dentist and length of dental practice.
There was no statistically significant difference in the pain that the dentist expected before the treatment and the perception of pain during the procedure.
Relationship between dental anxiety with the expected and actual pain
There was a statistically significant correlation between the overall level of anxiety and expected pain intensity (Spearman Rho = 0.401, P = 0.001). The correlation was positive, which indicates that the increase in anxiety increases the expected intensity of the pain. Dental anxiety in total was not statistically significantly associated with the actual intensity of pain (Spearman Rho = 0.080, P = 0.524).
The difference in the patients’ pain and pain perception of dentists
There was no statistically significant difference between the patient's expected pain and the dentist's assessment of the patient’s expected pain. Also, there was no statistically significant difference in the actual patient's pain and dentist's perception of the actual pain, which indicates how well dentists assess the intensity of patient's pain. Although the mean value of the expected patient's pain is higher than the mean value of the dentist’s expected pain, the difference was not great enough to be statistically significant (Figure 1).
Correlation between the patient's level of anxiety and the dentist's assessment of the level of anxiety
There was a statistically significant correlation between the patient's level of anxiety and dentist's assessment of the level of anxiety, considering both the overall anxiety (Spearman Rho = 0.460, P <0.001), and with respect to all three particles of the dental anxiety scale. Maximum correlation between dentist's assessment of patient's anxiety and patient's own assessment was assessed by the following particle “What do you think you will feel while sitting in the dental chair and waiting for the dentist to prepare the instruments for work? (Spearman Rho = 0.480, P <0.001).
Over the past decade, dentistry has made great progress in the development of technology, materials and infection control, which led to an increase in awareness of oral health. However, dental anxiety remained a problem for many patients (6). Successful implementation of endodontic treatment in patients with high levels of anxiety and fear is a significant problem in everyday dental practice (16, 17). Earlier studies have demonstrated a close correlation between the level of pain and dental anxiety (13, 18) which was confirmed in this study. In order to facilitate recognition of such state, and thus establish better relations and more efficient methods of therapy, behaviour patterns and characteristics of anxious patients were described (7, 15). This primarily refers to the difficulty in communication, prolonged therapy to avoid appointments and occurrence of postoperative pain (19). Poor oral health status and dissatisfaction with the aesthetic appearance of teeth (which leads to a lack of confidence, and thus more anxiety), defensive attitude towards the dentist, discontent and criticism of the intervention provided, crying, aggressive behaviour, sleep and eating disorders, and taking various drugs were also established in those patients (16). It has been shown that the demographic indicators have a role in the development of dental anxiety. On average, one out of six adults suffers from various forms of fear and anxiety (16). Generally, it can be said that the level of anxiety decreases with age. It is greatest in adolescents, in most cases it is the result of distorted views of dentistry due to their own bad experiences in childhood and influences of the negative attitude of parents, friends and the media (14). Also, younger patients show the least satisfaction with the provided procedure (20). Studies have shown that the average age at which reduction of fear begins is 40 years for both men and women (21). This may be explained by the increased tolerance of frequent exposure to stressful situations over a prolonged period, and life experience that shapes the behavioural characteristics of the individual (15). There were differences with regard to gender which suggest that the highest prevalence of anxiety is among women between 26 and 35 years of age, although in this population frequent dental visits were observed (5, 16, 20). This study also observed an increased total score of anxiety in women, although there was no statistically significant difference. Research that specifically deals with dental fear in women showed an increase in heart rate up to 24 hours in advance. Also, this group showed a seemingly small number of fillings (because of the smaller number of teeth) and a higher incidence of caries compared to women without dental fear (12). The frequency of dental visits is significantly reduced in anxious patients. In addition, they tend to use subterfuges to avoid the scheduled date (5, 12). This has also been proven in our study, in which it was shown that patients who visit the dentist once every few years were more anxious compared to those who visit it annually. Time spent in the waiting room is a factor which proportionally increases the level of anxiety and stress response of individuals who manifested a significant increase in blood pressure and cortisol. Before the procedure anxious patients show an increase in blood pressure, heart rate being increased by an average of 4 beats per minute (16, 22-24). Once he/she sits in the dental chair, the patient is exposed to new triggers of fear. They can be systematically displayed as "4S rule", and have to draw attention of the dentist during the operation (16). These are:
Sights - visual experience (needles)
Sounds - Sounds (micromotor, turbine)
Sensations - feel (vibration)
Smells - smells (different dental materials)
This study showed a statistically significant correlation between the patient's level of anxiety and the dentist’s recognition of the same. The largest correlation of dentist's assessment of anxiety was estimated by the question “What do you think you will feel while sitting in the dental chair and waiting for the dentist to prepare the instruments for work?
However, one should not ignore the stress level of the dentist. One study found a higher heart rate and blood pressure of the dentist who conducted the procedure on anxious patients (5). Negative feedback causes tense situations for both the patient and the dentist.
The success in performance of any complex procedure is reduced under stress. Due to the complexity of endodontic treatment, it is likely that the level of stress that the patient transmits reflects on the quality of the dentist’s performance (3). Key factors that lead to a pleasant environment are pain prevention, positive interaction, words of encouragement and a sense of control over the situation (25).
As for the preference of patients with respect to the gender of the dentist, studies have shown no difference in reports of pain, despite the stereotypes about women who are gentle and compassionate. This has been confirmed by our study. Personality and skills of the dentist proved to be more important factors than gender (9, 20). Interestingly, the patients reported experiencing less pain when procedures were performed by dental students. In a study in which the patients’ satisfaction with the treatment was compared with regard to the type of clinics they were treated in private practices overcame public services (20). The last two hypotheses could not be compared in this study because the majority of procedures were performed by students, 52 (78.8%) at the School of Dental Medicine, University of Zagreb.
Despite the relatively common occurrence of dental anxiety, it is surprising that dentists show a lack of understanding and lack of knowledge about the psychological approach that would lead to a reduction of fear (5). Not so long ago, dentists could afford to ignore this problem and these patients represented only an aggravating circumstance of the work. Today, due to legal regulation and the threat of lawsuits, dentists must pay particular attention to anxious patients and develop communication techniques with patients (26).
Many earlier studies on pain in endodontics have tried to correlate with postoperative pain factors such as one-visit endodontic treatment, various materials for filling the root canal, different ways of performing the procedure, the use of analgesics, anaesthetics, antibiotics, and preoperative pain. However, few researches have been directly focused on the experience of patients (2).
Dentists’ awareness about anxious patients is essential for establishing good communication and proper psychological approach. Apart from various questionnaires and scales to assess pain, the dentist can identify such patients by already mentioned characteristics or simple question of how the patient feels. If there is no anxiety, this issue will not cause it (7, 27). Psychological approaches such as behavioural therapy and hypnotherapy represent a higher level of pain control, after which the patients showed a statistically significant reduction of fear, measured with Dental Anxiety Scale (DAS). However, these methods require care and a systematic commitment to the patient, factors the implementation of which is questionable in dentists’ daily work (28). Future research should be focused on finding the optimal method of accessing patient anxiety and individual ways of reducing pain. This primarily involves educating dentists and expanding profession beyond science and clinical work.
In order to reduce fear and get the most accurate information about main difficulties and maintain cooperation with the patient during treatment, the clinician should establish and maintain control of the situation, gain the confidence of the patient, get his attention and sympathy, and treat the patient with respect. Since the level of dental anxiety is associated with increased intensity of expected pain, a vicious cycle of pain and anxiety may be terminated by giving positive information to the patient before and during endodontic procedures. The patients will base their predictions on actual facts and will become aware that there are effective methods of pain control and that pain in endodontics is not inevitable. Managing these components can significantly reduce the perception of pain and raise the threshold of reactions, thus facilitating the process.