In this study, the new 2018 periodontitis classification and validated questionnaires were used to determine the relationship among dental fear, SRP pain and periodontal status.
The previous 1999 periodontitis classification was used extensively, but its major drawbacks were substantial overlap and lack of clear pathobiology-based distinction [22]. Whereas, the new classification provides an assessment of periodontitis on the basis of stages and grades [22]. Participants of this study had no systemic disease and smoking history, and the follow-up visits were set as 6 months following therapy. In this case, we did not include grading into the population assessment.
Dental fear should be studied with regard to the situation to which it pertains, the reactions it evokes, and its duration [13]. This study used DAS, DFS and S-DAI to evaluate dental fear from various aspects. DFS reflects dental fear informatively, which assists clinicians in obtaining a better understanding of the patient’s fear, while DAS measures dental fear in a more general manner [36]. Meanwhile S-DAI focuses on psychometric grounds [30], with nearly half of its items representing the emotional reactions of patients with respect to dental treatment [13, 36]. Santuchi et al reported significantly lower dental fear levels at the first attendances as suggested by DAS, but no statistical significance on DFS [14]. Thus, researchers draw different conclusions towards the same issue based on their analyses of different scales. In the current study, the scores obtained from DAS and S-DAI were significantly decreased at the subsequent visits 6 months in most scales, but changes in DAS and S-DAI scores were not significant in stage I and II. Even though there was a discrepancy in the statistical significance of each scale, the combination of three dental fear scales was consistently decreased at the subsequent visit 6 months later, and the mean values of all the scales also declined. In this case, this study established a combination of three scales for analysis, which could enhance the accuracy of the results.
Notably, the present study demonstrated correlations between periodontitis stages and dental fear. Periodontal status was an important factor affecting dental fear, since worse periodontal status were found to contribute to higher dental fear level [13]. Guentsch et al suggested that patients with higher dental fear levels experienced more bleeding on probing (BoP), which had negative effects on periodontal health [37]. Levin et al proved that periodontal clinical parameters, including plaque index, radiographic bone loss and probing depth were correlated with DAS [8]. Bell et al reported that dental fear was associated with bleeding gums as a sign of gingivitis [38]. Notwithstanding, controversial opinions still exist. Delgado-Angulo et al concluded that dental fear was not related to the number of teeth with PD≧4mm[21], meanwhile Eitner et al stipulated that anxiety was not associated with periodontal status[39]. These differences in dental fear levels may be attributed to the high variability of periodontal parameters, so the new classification is perfectly habilitated to avoid the uncertainty due to indicators.
Pain is an ‘unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described by the patient in terms of such damage’ [40]. As a major component of dental fear, fear of pain associated with dental treatment was identified [41]. SRP is often associated with pain and discomfort, albeit the occurrence of pain is variable and dramatically different among patients [20]. The VAS scores representing the pain perceived during periodontal procedures range from approximately 20-80mm [42, 43]. In this study, the VAS during SRP was 24.79±14.61, which was significantly associated with dental fear. Tickle et al discovered that subjects with dental fear were 2.3 times more likely to experience pain after dental treatment [44]. Fardal et al and Staunton et al drew a similar conclusion on various aspects of focus [45,46]. Based on these facts, Schirme et al suggested that periodontal treatment should encourage healthcare professionals to design health and comfort treatment strategies that will cope with the dental fear of patients and reduce discomfort during dental treatment [20]. On the other hand, Kyle et al and Eli et al reported that patients reported less pain during treatment than they predicted [47,48]. Therefore, evaluation of dental fear and pain levels is crucial for a successful periodontal treatment.
In the present study, a statistically significant correlation was identified among dental fear, pain and periodontal status. The dental fear levels were all reduced across every stage of periodontitis patient, especially in stage III and IV, which highlighted the necessity of treatment intervention. Santuchi et al reported that periodontal status was improved and experiences of fear were reduced during SRP, which was similar to our study [14]. Fardal et al reported that anxiety levels decreased with the progress of the periodontal therapy [49]. Consequently, clinicians should notice the level of dental fear and break the ‘vicious cycle’ in periodontitis patients [11,12].
The proportion of patients with periodontitis stage III (35.48%) and IV(41.94%)in high dental fear group was significantly increased compared to those in low dental fear group (stage III 21.34%, stage IV 19.10%). Despite the fact that the dental fear level of patients were reduced at the 6 months return visit, the dental fear values were still high, especially in stage III and IV. Stage I and II were considered to initial and moderate periodontitis, while stage III and IV were severe and advanced periodontitis [50]. This was in accordance with the findings in other studies demonstrating that patients with severe periodontitis had poorer oral health, worse functional limitation, physical pain, and psychological incapacity domain scores, in comparison to those with mild and moderate periodontitis [51]. Based on the results of our study, clinician should pay more attention to dental fear in stage III and IV periodontitis patients.
This is the first study in the literature to measure the periodontal status based on periodontitis stages, aiming to evaluate the relationship between dental fear and pain. It is worth mentioning that our study comprises several limitations. For starters, the population size of the current study was relatively small although statistically sufficient. Secondly, lack of inter-rater reliability restricted the precision of the current study. Finally, grading assessment in the future study should incorporate a clinical evaluation of new periodontitis classification.