Effectiveness of Personalized Oral Hygiene Advice Delivered by Artificial Intelligence or Dental Professionals Versus Standard Oral Hygiene Advice on Oral and Systemic Health in Community-based Type II Diabetes Patients: A Randomized Controlled Trial

Diabetes is a systemic condition characterized by elevated blood glucose levels and is associated with multiple long-term complications. This systemic disease is mutually linked to inflammatory gum diseases through circulating inflammatory mediators. Controlling inflammatory gum diseases improves blood glucose levels and reduces long-term complications. While maintaining good oral hygiene through home care is essential for managing inflammatory gum diseases, close supervision of patients' home care is labor-intensive and expensive. Artificial intelligence (AI) has been used to provide personalized advice on the adequacy of patients' home care (oral hygiene). We hypothesize that the use of AI can improve home care, thereby enhancing both gum health and systemic health, compared to the absence of AI in chronic disease healthcare.

Diabetes is a serious public health problem and accounts for 9% of all deaths worldwide. According to the World Health Organization (WHO), by 2030, the number of diabetics will increase to at least 366 million worldwide. In Europe, the diabetic population is estimated at 66 million, a number that will rise to 89 million by 2045. However, these figures are not as dramatic as in America and many other low- and middle-income countries. Diabetes has become a major public health problem in China, increasing rapidly in last decades. About 90% of diabetes patients have type 2 diabetes mellitus (T2DM ), which causes a range of health complications, such as eye, mouth, and skin infections, cardiovascular diseases, blindness, and kidney failure, and can lead to lower limb amputation, reducing patients' quality of life and imposing a burden on them, their families, and the wider society. The main predisposing factors for T2DM are the existence of prediabetes, obesity, age ≥ 45 years, a family history of T2DM in first-degree relatives, a lack of physical exercise, the onset of gestational diabetes or the birth of a new-born weighing > 4 kg, the presence of non-alcoholic fatty liver disease, and smoking.

Prevention of T2DM is a major challenge worldwide, as both its prevalence and incidence are increasing rapidly. The main symptoms of T2DM are typical and common to all types; they include polyuria, polydipsia, polyphagia, dry mouth and/or dry skin, excessive fatigue, blurred vision, and trauma, such as cuts and bruises that are slow to heal.

Chronic oral diseases are significantly more common and more severe in diabetic patients. In addition to gingival infection and periodontal inflammation, there may be complications of implants, caries, dry mouth, bacterial and fungal infections, oral malodour, and slow healing of wounds from dental treatments. In addition, the Candida species are seen more often in people with diabetes than in healthy people. Periodontitis is the main and most important complication of T2DM, with a prevalence of 7 in 10 adults having some type of periodontal disease, and almost half of this population having moderate or severe periodontitis. Age, sex, education level, family income, smoking, oral hygiene-related behaviours, T2DM, and other comorbidities, such as some autoimmune diseases, have been identified as important potential risk factors for periodontitis in many studies.

The findings of the studies also show that T2DM is associated with an increased risk of tooth loss because of periodontal disease, possibly through the mechanism of inflammation: directly due to an inflammatory response of the gums and indirectly due to the creation of a substrate resulting from reduced saliva production secondary to medication. In particular, periodontal disease is caused by changes in collagen metabolism-and consequently, in periodontal fibers-and by the presence of microbial plaque and poor hygiene in most diabetics, resulting in resorption of the gums, the underlying connective tissue, and the jawbones, leading to loss of teeth.

There has been growing interest in an alternative pathway known as the enteral route. Recent research has demonstrated the interconnectedness of the oral cavity and gastrointestinal tract, highlighting their mutual influence, particularly in terms of microbiological aspects. The discovery that even healthy individuals harbour habitual oral microbes in their feces has contradicted the traditional belief that multiple barriers were responsible for maintaining the segregation of oral and gut microbiota. One possible explanation is the transfer of oral bacteria and their by-products from the mouth to the digestive tract through swallowing. Upon reaching the gut, these bacteria may induce inflammation, disrupt the gut microbiota, and generate metabolites that facilitate pathological processes. Studies have revealed the presence of circadian rhythms in both oral and gut microbiota in humans, which suggests that, in addition to dietary choices, the timing of food consumption could also impact the composition of oral and gut microbiota.

The relation between oral health and diabetes management has long been under-appreciated. People with diabetes have a 2-3-fold greater risk for periodontitis compared to people without diabetes, but also a higher incidence of caries due to dry mouth. The progression and severity of periodontitis are also greater in people with poorly controlled diabetes. According to the American Academy of Periodontology, 50% of diabetics up to the age of 35 suffer from periodontal disease, a figure that rises to 80% at the age of 45-54 years, compared to 60% in the healthy population. A growing body of data indicates that oral inflammation has an impact on general diseases.

It was reported that over 85% Chinese adults suffered from periodontal disease. A previous review considered the relationship between periodontitis and T2DM as bidirectional, with diabetes leading to increased risk for periodontitis, and periodontal inflammation negatively affecting glycaemic control. A number of studies revealed correlations of periodontal diseases with impaired fasting glucose, impaired glucose tolerance and HbA1c level. Poor oral hygiene is the most important cause of periodontal disease. Self-reported measures of oral hygiene have been associated with periodontal disease.

Unfortunately, the majority of diabetic patients are unaware of the connection between diabetes and their oral health. There is a need for educational programs for diabetic patients that emphasize this relationship, explain the unpleasant effects of poor oral health on the patient's glycaemic control, and recommend behaviours that promote good oral health, but also overall wellbeing and a better quality of life.

It has been suggested that oral hygiene education and oral health behaviour change may have a positive impact on periodontal condition and systemic inflammatory status. Oral hygiene instruction (OHI) ais regarded as an important treatment procedure for dental patients. Despite growing evidence on the benefit of non-surgical periodontal treatment (NSPT) in improving periodontal inflammation, facilitating glycaemic control, and reducing metabolic and proinflammatory markers in diabetic patients, data in the effectiveness of OHI in diabetic patients with remain scarce.

The American Academy of Periodontology treatment guidelines stress that periodontal health should be achieved in the least invasive and most cost-effective manner. This is often accomplished through NSPT, including OHI, scaling and root planning of the root surface to remove plaque, calculus and bacterial toxins from deep periodontal pockets. Adjunctive therapy, such as antimicrobial therapy and host modulation are incorporated into the treatment regimen as required on a case-by-case basis. Intervention trials have suggested that there was an improvement in glycaemic control in people with diabetes following non-surgical periodontal therapy.

Nowadays, artificial intelligence (AI) can readily assist in the self-detection of diseases, including gum disease, allowing older adults to identify diseases early and prevent further complications. The use of AI-based mHealth has become increasingly effective in promoting periodontal health by adopting simple, AI-driven self-tests using smartphones. Another systematic review done by our team found that AI-based mHealth for oral hygiene and gum disease monitoring showed clinical effectiveness across different clinical scenarios. Our team has already launched an AI system for the detection of gum disease using smartphone intraoral photography, in which the system can detect colour changes of gum inflammation in specific sites in intraoral photography and diagnose as three simple situations (severe, mild and no inflammation). Our AI system have high sensitivity 92% to identify disease from sites that have gingivitis, and high specificity 94% to identify healthy tissue from sites that have no gingivitis using professional intraoral photography. Moreover, we have tested that the accuracy of colour captured by a smartphone is comparable to that captured by a professional single-lens reflective camera. Our team already have applied our AI-powered smartphone photography among 38 older adults in 5 day-care centres of Hong Kong to test their gum health. The result is promising with accuracy of 96% sensitivity and 82% specificity. The present study will apply AI technology on disease detection and giving personalized OHI closely to the patients to maintain periodontal health and consequently diabetic control.

Inclusion criteria

• Subjects who are >18 years of age and able to give informed consent.
• Subjects who are mentally and cognitively healthy.
• Subjects who are with T2DM state with impaired HbA1c > 6.4%, or impaired fasting plasma glucose level > 6.9 mmol/L or impaired plasma glucose level after 2h OGTT > 11.0 mmol/L.
• Subjects who can speak, read, or understand Cantonese to complete the questionnaire.
• Subjects who can practice oral hygiene procedure (regular tooth brushing and interdental cleansing/flossing/brushing) daily on their own independently.

Exclusion criteria

• Subjects who have mental illness, or similar problems that unable to complete the satisfaction questionnaire.
• Subjects who cannot perform oral hygiene procedure (regular tooth brushing and interdental cleansing/flossing/brushing) by any condition of oral cavity such as tumor or maxillomandibular fixation.