Periodontitis is a chronic oral disease caused by the corrosion of dental tissues by pathogenic microorganisms that form periodontal pockets and are absorbed by the alveolar bone, eventually leading to tooth loss. Epidemiological studies have shown that the incidence of periodontitis is increasing and that the elderly account for a relatively high proportion of the population with periodontitis[1,2]. Anxiety and depression are adverse emotions such as tension and fear that occur in patients with periodontitis during treatment and are prevalent in patients of all ages, mainly manifested as fear and avoidance of dental treatment. The unpleasant emotional experience directly affects patients' ability to face diseases. In addition, adverse emotions can aggravate the stress reactions of patients, leading to the aggravation of their original condition and affecting their oral health. Increasingly aggravating oral diseases cause patients to fall into a vicious cycle of depression, anxiety, and avoidance. Therefore, it is important to clarify the current state of depression and anxiety in patients with periodontitis and the factors that may lead to adverse psychological emotions in patients[3-5]. To date, many clinical studies have mainly focused on the treatment of patients with periodontitis and anxiety and depression, whereas related studies on factors that may lead to anxiety and depression in patients with periodontitis are rare. In view of this, this study focused on observing the status of anxiety and depression in patients with periodontitis and analyzing the risk factors that may lead to anxiety and depression in these patients, in order to improve their negative psychology and overall health.

Oral cavity-related diseases not only affect the function of oral organs, but also affect the whole-body health of patients and their psychological development. With the development of the "biological-psychological-social medicine" model in clinical medicine, clinical treatment is increasingly not only for the diagnosis and treatment of the disease itself, but also for holistic medical treatment[14-16].

The results of this study showed that among the 100 included patients with periodontitis, 38 (38.00%) developed depression according to the SDS score, and the average SDS score was (68.52 ± 5.85) points. According to the SAS, there were 40 patients with anxiety, and the incidence rate was 40.00%; the average score of the SAS was (72.15 ± 4.15) points, indicating that anxiety and depression were common in patients with periodontitis. The related mechanisms of clinical anxiety and depressive negative emotions affecting periodontitis are relatively complex and mainly manifest in two aspects. The first is pituitary-adrenal axis dysfunction, neuroendocrine changes, and increased secretion of glucocorticoids in patients with periodontitis combined with anxiety and depression, as well as the inhibition of the immune response of the body and increased susceptibility of the body to pathogenic bacteria of periodontitis. Second, the life attitudes of patients with periodontitis and anxiety and depression are mainly pessimistic. Gingival swelling, bleeding, and even loss in patients with periodontitis are likely to increase their negative emotions, thus forming a vicious circle that is a negative factor for both negative emotions and disease control[17-19]. Therefore, it is necessary to explore factors that may lead to anxiety and depression in patients with periodontitis.

The results of this study showed that compared with the non-occurrence group, the occurrence group had relatively high ages (≥ 60 years old), hope level (low level), education level (high school or below), disease perception (poor), and sleep disorder (yes). The negative coping dimension score of the SCSQ and DFS score in the occurrence group were higher, while the score of positive coping dimension of the SCSQ was lower. The results of multiple logistics regression analysis showed the influencing factors leading to anxiety and depression in patients with periodontitis were as follows: (1) Age: Elderly patients with periodontitis have a relatively low quality of life, and such patients bear a heavy burden of worry about the prognosis of the disease, that they will impose a burden on their children and loved ones and affect the quality of life of themselves and their families. Consequently, patients experience severe negative emotions related to anxiety and depression[20]; (2) Hope level: The lower the hope level, the more negative and pessimistic patients would be when facing the stressors, unable to face the disease squarely, unwilling or rejecting cooperative treatment, lacking confidence in disease recovery, feeling helpless when facing the disease, and trapped in negative emotions such as anxiety and depression for a long time, which are not conducive to disease diagnosis and treatment[21]; (3) Education level: For patients with low education level, the knowledge level is relatively low, the learning ability is not high, and the understanding of the disease cognition is not thorough. In addition, the erroneous understanding of the disease leads to the occurrence or even aggravation of anxiety and depression in patients[22]; (4) Disease perception: Patients with poor disease perception have no correct cognition of the occurrence, development, and prognosis of the disease and have incomplete disease understanding, which leads to patients not fully comprehending disease diagnosis and treatment and unable to make a reasonable judgment on the prognosis. Patients had a stronger sense of abnormal experiences of the disease and were excessively concerned about its negative effects. Consequently, anxiety and depression are more prominent in these patients[23]; (5) Sleep disorder: In patients with sleep disorder, the body immunity will decrease, the inflammatory pathways will be activated, and the inflammatory reaction will be aggravated. The increasingly aggravated inflammatory reaction leads to the aggravation of the psychological burden on patients and causes them to worry more about the treatment effect and development of the disease after treatment. In addition, negative emotions, such as anxiety and depression, act on the body and affect sleep quality, thus forming a negative cycle that is not conducive to the recovery of the patient's condition[24]; (6) Coping styles: There were two kinds of coping styles: negative and positive. A positive coping style can weaken the psychological burden and promote disease recovery, whereas a negative coping style strengthens the psychological burden and delays disease recovery. The reason that patients with periodontitis mostly adopted a negative coping style was related to persistent toothache and bad breath, which led to an inferiority complex. Second, fear of operating instruments during oral treatment, high treatment costs, and uncomfortable treatment experiences were also related. Moreover, anxiety and depression resulting from negative coping styles gradually increase and persist over time[25]; and (7) Dental fear: The treatment cycle of periodontitis is long, and during the treatment process, patients experience severe discomfort. Therefore, patients with periodontitis generally experience dental fear, which leads to poor compliance in patients receiving the diagnosis and treatment. Whether patients still have phenomena such as delayed treatment and a prolonged treatment cycle, which will cause unsatisfactory diagnosis and treatment effects, is more likely to aggravate patients' rejection psychology, and negative emotions of anxiety and depression are generated and gradually strengthened[26].

However, due to the limited number of samples included and the retrospective nature of this study, there are limitations with regard to the inclusion of relevant indicators, and the credibility of the study needs to be verified by expanding the sample size in the future.

In summary, age, hope level, education level, disease perception, sleep disorders, coping style, and dental fear were all associated with anxiety and depression in patients with periodontitis.