Oral health status and diabetes type 2 control have a two-way relationship, and both of them effect on quality of life. This study aimed to investigate the effectiveness of oral health educational intervention on self-care behaviors, and quality of life of type 2 diabetic patients using the health belief model (HBM).In this quasi-experimental study, 120-diabetic patients, participated (60 in each intervention and control group) in Shiraz, Iran, between August 2024 and March 2025. Data were collected through HBM based researcher made questionnaire, Geriatric Oral Health Assessment Index, and clinical examination based on DMFT and CPITN indices, before and three months after the intervention. Four 60-minutes educational sessions were conducted for intervention group, using interactive educational methods. Data were analyzed by SPSS 27 at significance level of < 0.05, using independent sample t-test, paired sample t-test, and Cohen's d as effect size coefficient.The mean ages of the control and intervention groups were 53.75 ± 7.55 and 56.07 ± 7.17 years respectively. After the intervention, except for perceived barriers which decreased significantly (P < 0.001), and DMFT and CPITN which did not change, mean scores of all other study variables were increased significantly in intervention group (P < 0.001). The intervention had large effect sizes on perceived susceptibility, benefits and Quality of life, while effect sizes for knowledge, perceived severity and barriers and oral hygiene behaviors were at moderate level.The educational interventions based on the behavioral change models, especially HBM can be effective in improving the self-care behaviors and quality of life of of patients with diabetes.
Type 2 diabetes (T2D) is a progressive and multifactorial metabolic disorder characterized by chronic hyperglycemia resulting from impaired insulin secretion, insulin resistance, or both. It is one of the most prevalent non-communicable diseases (NCDs) globally and is associated with significant morbidity, mortality, and economic burden. As of 2017, more than 462 million people were living with T2D worldwide, representing approximately 6.8% of the global population. The burden of this disease continues to rise, particularly in low- and middle-income countries. According to the 2022 report by Iran's Non-Communicable Diseases Research Center, the national prevalence of diabetes was estimated at 14.2%, with a slightly higher rate among women (14.7%) than men (13.5%).
T2D is associated with a wide array of long-term complications that affect multiple organ systems, including the cardiovascular, renal, ocular, and nervous systems. These complications not only reduce life expectancy but also significantly impair patients' quality of life. Although no definitive cure exists for diabetes, effective management is achievable through sustained self-care practices, including adherence to a balanced diet, regular physical activity, consistent blood glucose monitoring, and appropriate pharmacologic interventions.
Among the less frequently emphasized but clinically significant complications of T2D are oral health disorders, particularly periodontal disease and dental caries. There is a well-established bidirectional relationship between diabetes and periodontal health: poor glycemic control can exacerbate periodontal inflammation, and conversely, untreated periodontal disease can impair glycemic regulation, creating a self-perpetuating cycle. Despite this interrelationship, oral health often remains a neglected aspect of diabetes management. Many individuals with diabetes experience poor oral health-related quality of life (OHRQoL), characterized by pain, tooth loss, mastication difficulties, and psychosocial distress.
Oral health and systemic health are intrinsically linked. A growing body of literature supports the association between oral infections and systemic diseases such as cardiovascular disorders, chronic kidney disease, and adverse pregnancy outcomes. In individuals with diabetes, OHRQoL is influenced by factors such as the severity of oral conditions, duration of diabetes, and access to preventive care. However, studies suggest that limited awareness and suboptimal attitudes toward oral health are common in this population. For instance, in an Iranian study, Goodarzi et al. (2019) identified poor knowledge and negative attitudes as significant predictors of inadequate oral hygiene behaviors among patients with diabetes.
To improve oral health outcomes in people with diabetes, targeted health education interventions grounded in behavioral science are essential. Evidence supports the effectiveness of theory-based interventions in promoting health behavior change and addressing perceived barriers. Among these, the Health Belief Model (HBM) is one of the most widely applied frameworks for understanding and influencing health behaviors, including those related to oral hygiene. The HBM posits that individuals are more likely to engage in health-promoting behaviors if they perceive themselves to be susceptible to a condition (perceived susceptibility), understand the severity of its consequences (perceived severity), recognize the benefits of preventive actions (perceived benefits), believe that obstacles can be overcome (perceived barriers), and have confidence in their ability to take action (self-efficacy).
While numerous studies have utilized the HBM to enhance oral health behaviors in the general population, there is a paucity of research focusing specifically on individuals with T2D. Considering the high prevalence of T2D and the critical role of oral self-care in preventing complications in this group, the present study aimed to evaluate the effectiveness of an oral health educational intervention based on the Health Belief Model in improving self-care behaviors and oral health-related quality of life among middle-aged and older adults with type 2 diabetes. Beyond prior HBM-based oral health interventions in type 2 diabetes that often focused either on psychosocial constructs or on selected clinical indicators, the present study integrates HBM constructs, OHRQoL, and objective indices (DMFT, CPITN) within the same population, offering a more comprehensive evaluation to inform both clinical and community strategies.
Despite these valuable contributions, prior studies on oral health promotion in people with type 2 diabetes have several limitations. Many relied primarily on self-reported outcomes without integrating both psychosocial and clinical indices, making it difficult to capture the full impact of interventions. Furthermore, most interventions were short-term and did not consider the irreversible nature of dental indicators such as DMFT or the role of environmental factors like access to dental services. Additionally, existing HBM-based studies in diabetes populations often addressed either specific constructs or selected behavioral outcomes, rather than providing a comprehensive framework that connects beliefs, behaviors, and objective oral health outcomes. These gaps highlight the need for more integrative and theoretically grounded interventions, as addressed in the present study.