Psychological distress and anxiety compared amongst dental patients- results of a cross-sectional study in 1549 adults

Dental fear and anxiety are not commonly directed towards the dental practitioner but more towards the treatment and the possibility of pain. Research by Weiner and Sheehan [1] further differentiated the origins into exogenic and endogenic. The influence can be environmental and due to stigmatizing experiences (exogenic) or part of generalized anxiety (endogenic). Patients with dental fear are a challenge for the dentist and the dental staff and can cause more stress responses [2]. Studies have shown that 70% of the general population feels anxious before a dental examination, 20% of that group are classified as highly anxious, and 5% evade dental treatments fully [3]. Dental anxiety, causing the patient to evade treatment, is a failure of modern dentistry to develop towards minimal invasiveness. Even though pain can be reduced to a minimum with modern day anesthetics, it seems that the fear of pain overshadows the actual pain. Anxiety disorder is pervasive, as 25% of all general practitioners can diagnose symptoms among their patients [4]. When questioned, patients label dental anxiety as the second biggest trigger for psychological distress at 21%, just after public speaking at 27%. It is essential for a dentist to define which group of patients is likely to have dental anxiety. A study conducted on 73 subjects with dental phobia showed that 40% of this sample had a current Axis I diagnosis other than a simple phobia, with an anxiety disorder (20%) being the most common [5]. Mental disorders such as anxiety disorder or depressive disorder could be highly associated with dental fear. Patients with post-traumatic stress disorder are affected most commonly.

Earlier studies exposed women to have a higher affinity for developing anxiety towards dental treatment [6]. Hakeberg compared the results of a male and female Swedish population with the Dental Anxiety Scale. Results showed a significantly higher dental anxiety in women between the age of 20 and 39 years compared to younger and older age groups [7]. A similar study by Stouthard found women between the ages of 26 to 35 to be most prone towards dental anxiety [8]. These results were confirmed in by Enkling.

Furthermore, it was determined that patients with a developed dental anxiety demand higher attention before, during and after the dental treatment [9]. Most patients wished for the most accurate information about the dental treatment they received, a sympathetic dentist and a pain-free dental examination. This evidence emphasised the significance of identifying dental fear in patients and being able to adapt towards their demands. Age seems to be a recurring factor, as fear of dental treatment is not common above the age of 60 [10–12]. Recent studies determine younger age groups to show higher levels of dental fear than older age groups [13]. However, it was also found that 15 to 25-year-olds showed fewer signs of dental fear than older individuals [14].

Due to these results, our aim in this study was to determine if there is a correlation between psychological distress measured with the frequently used BSI-18 and dental anxiety investigated by DAS. Furthermore, we tried to find a relationship between psychological distress and dental anxiety to age groups and gender.

In different studies, throughout 3 years (2012–2015), approximately 2000 patients were asked to participate. Out of these, 1549 (77.5%) patients were included in our research. The data was collected independently in the research group for Medical Psychology and Medical Sociology in Dresden (Germany). DAS and BSI-18 questionnaires were handed out to dental patients before their routine treatments. Patients were also given a set of descriptive questions, collecting information about age and gender differences. The questionnaires were then examined in 2016 by our research group. All patients needed to be 18 years old and give written informed consent. Only patients providing written informed consent were included as study participants. All questionnaires were analyzed using IBM SPSS V23 to reveal significant similarities or differences. The mean total values were calculated and then analyzed using an independent sample t-test. Chi-squared tests were used to determine significance between questionnaire categories and sample characteristics. Cohens d respectively Cramers v were calculated as estimates of effect sizes. The coherence between dental anxiety and psychological distress were evaluated using Pearson correlations. P values equal or less than 0.05 were considered statistically significant. The research was conducted according to STROBE guidelines.

In total, 1549 patients completed the questionnaires. Fifty-six percent of the patients were female (865/1549 patients), and 51 % of patients were at or above the age of 46 (779/1525). The mean age was 45.68 years (SD 18.70, range 18–88 years).

Comparing the categories of the Dental Anxiety Scale to patients at or above and below the age of 46 showed no statistical significance. These findings were strongly in contrast to those of similar studies [10, 12, 21–24] showing a decrease in the prevalence of dental anxiety in older populations compared to younger populations. An explanation could be the classification into only two age groups and a generalization of the words “young” and “old”. A flaw of the Dental Anxiety Scale is the non-inclusion of local anesthetics and a strong influence of a patients judgment of the treatment. Patients are most afraid of the pain and bodily harm done by the injection [25], even though 40% of younger age groups prefer a treatment with anesthesia [26]. The Modified Dental Anxiety Scale (MDAS), modeled on the original anxiety scale by Corah, includes an additional question about anesthetics [10]. Findings for the sample groups showed a connection between age groups and dental anxiety using the MDAS [21].

The Brief Symptom Inventory-18 was used to compare the same age groups. Findings indicated a higher presence of depression and anxiety in younger than in older patients. Increased experience, emotional control, and immunity to stressful experiences are possible factors supporting these results [27]. The older patient might be not working anymore and therefore can recover and prepare better for stressful experiences. There are, however, indications that symptoms of anxiety and depression begin to increase again [28]. Therefore, it is important not to assume an older patient to not be at risk for anxiety and depression symptoms. These results further emphasize the need for a comfortable and reliable dental anxiety screening method.

When comparing dental anxiety and the Global Severity Index with the gender of our sample, female patients were more susceptible to psychological distress regarding a dental treatment than male patients. This was a confirmation of earlier studies [4]. Women have a higher chance of developing dental anxiety than male patients as we expected [29]. An explanation for this might be higher levels of neuroticism in women than men and it being correlated to anxiety [30–32].

Correlations between psychological distress and dental anxiety might be an indicator that patients with a generally higher level of psychological symptoms (depression, somatisation, anxiety) are at a higher risk for the development of specific anxieties such as dental fear. A similar study, comparing 212 patients with psychosomatic service with 95 healthy controls, confirmed these results [33]. The large sample size of this study was favorable in comparison to similar studies. Also, the use of a general population and not just patients with an existing diagnosis of anxiety allowed a non-biased view towards the results. However only patients voluntarily visiting a dentist were interviewed. Patients with a diagnosable dental anxiety and an aversion to dental visits could not be examined.

The BSI-18 and the DAS are scientifically reliable questionnaires and are frequently used for large sample sizes, as in this study. To improve the individual judgment of the patient’s well-being, the more detailed BSI with 53 items or even the SCL-90R with 90 items could be applied in a subsequent study. There are also several factors for which the Dental Anxiety Scale is often criticised, such as the answering scheme not being consistent across the questionnaire and, most importantly, not including a question about local anaesthetics. The Modified Dental Anxiety Scale, validated by Humphris, Morrison and Lindsay in 1995 [34], improved these flaws and can be an interesting alternative to Corah’s DAS.

All questionnaires were completed by the judgment of the patients themselves. It is therefore possible that some patients did not answer the questions truthfully and might have reduced the severity of their answers to avoid being singled out as a patient with dental anxiety. The treatment the patients were expecting after their survey was not captured on any questionnaire. Patients with acute pain might already be psychologically weakened, expecting more pain and therefore fearing the treatment more than someone waiting for a routine dental check-up.

Patients suffering from dental anxiety are restricted in their daily routine. Most of the time, these patients will only choose to make a dental appointment if the pain becomes too unbearable. If the dentist is unaware of the patient’s anxiety, the encounter can deteriorate. This should not be the experience first experience of an individual fearing dental treatment. Screening using the Dental Anxiety Scale is fast and easy and can prepare the dentist to handle the patient. This would, however, require that the dentist has been professionally prepared to treat a patient who fears his surroundings. Improvements can be made in preparing students during their training or given as a mandatory lecture. With the help of specialized practitioners and a fully prepared dentist, it may be possible to reduce dental anxiety in susceptible individuals.

Using a large sample of dental patients the results of the study showed strong associations between dental anxiety and psychological distress (somatization, depression, anxiety). Patients below the age of 46 and women report more psychological distress. Additionally, women described more dental anxiety compared to male patients.