Abstract

Diabetes mellitus (DM) represents a formidable global health challenge, with its prevalence escalating dramatically worldwide, particularly in low- and middle-income countries. This rise is acutely felt across the African continent, where millions remain undiagnosed and untreated, leading to heightened morbidity and premature mortality. Concurrently, oral diseases, often overlooked in national health agendas, present a substantial public health burden in Africa, exhibiting the highest global prevalence of severe periodontal disease. This paper comprehensively explores the intricate, bidirectional relationship between diabetes and its diverse oral complications, including periodontal disease, xerostomia, oral candidiasis, dental caries, and impaired wound healing. Detailed pathophysiological mechanisms, encompassing enhanced inflammatory responses, oxidative stress, immune dysregulation, and altered oral microbiota, are elucidated to provide a foundational understanding of disease progression. Furthermore, the report synthesizes the latest clinical trials and research breakthroughs, highlighting advancements in periodontal therapy, novel host modulation strategies, emerging salivary diagnostics, and the burgeoning field of oral microbiome research. A critical focus is placed on the unique challenges and promising interventions pertinent to the African context, addressing workforce shortages, policy deficiencies, and the imperative for culturally sensitive, community-based approaches. The paper concludes by advocating for integrated, interprofessional care models as essential for optimizing both oral and systemic health outcomes in individuals living with diabetes, underscoring that oral health is an indispensable component of comprehensive diabetes management.

1. Introduction

1.1. Global and African Burden of Diabetes and Oral Health

Diabetes mellitus (DM) has emerged as a rapidly intensifying global health crisis, imposing a substantial burden on healthcare systems and individual well-being. The worldwide prevalence of diabetes among adults aged 18 and above has more than doubled over the past three decades, surging from 6.8% in 1990 to an alarming 14.1% in 2022.¹ This escalating trend is particularly pronounced in low- and middle-income nations, where access to diagnosis and treatment often remains limited.

The impact of this global epidemic is acutely felt across the WHO African Region, which faces a disproportionately severe burden of diabetes. The prevalence of diabetes among adults aged 18 and above in this region has surged from 6.4% in 1990 to a staggering 10.5% by 2022, affecting an estimated 54 million individuals.¹ A critical concern is that over half of these individuals, exceeding 34 million people, remain undiagnosed and untreated, resulting in significant gaps in essential care.¹ This substantial treatment gap contributes directly to adverse health outcomes, including a higher rate of premature deaths from diabetes, with 58% of deaths occurring before the age of 70 in Africa, compared to a global average of 48%.¹

Concurrently, oral diseases represent a significant, yet frequently overlooked, public health challenge throughout Africa.² The WHO African Region records the highest global prevalence of severe periodontal disease, affecting 22.8% of individuals aged 15 and older.² Alongside this, the region experiences high rates of untreated dental caries, impacting 28.5% of those over 5 years old and 38.6% of children aged 1–9 years.² In 2019, oral diseases collectively affected an estimated 480 million people (43.7%) in the region, a burden projected to intensify with continued population growth.²

The co-occurrence of a rapidly increasing, largely undiagnosed diabetes burden and the highest global prevalence of severe oral diseases in Africa presents a compounding public health crisis. The high prevalence of undiagnosed and untreated diabetes means that many individuals are likely experiencing worsening complications without intervention. This situation suggests that the systemic neglect of oral health in national health agendas, as noted in various reports ², is not merely an oversight but a critical impediment to effective diabetes management and overall public health improvement. The lack of attention to oral health in policy frameworks contributes to exacerbated complications and higher rates of premature mortality observed in the region. Thus, addressing oral health is not simply about dental well-being; it is a fundamental component of mitigating the broader diabetes crisis in Africa.

1.2. The Bidirectional Relationship Between Diabetes and Oral Health

A robust and increasingly recognized bidirectional relationship exists between diabetes mellitus and oral health, particularly concerning periodontal diseases.³ This means that each condition can independently influence and mutually exacerbate the other, creating a complex interplay that affects overall systemic health.

In individuals with diabetes, particularly those with poor glycemic control, there is a significantly increased susceptibility to and severity of various oral problems, including gingivitis (early-stage gum disease) and periodontitis (advanced gum disease).⁶ The body’s inflammatory response to the bacteria found in dental plaque is notably heightened in diabetic individuals, leading to more severe tissue destruction, bone loss, and ultimately, potential tooth loss.⁸

Conversely, chronic oral diseases, especially periodontitis, can contribute to systemic inflammation throughout the body. This systemic inflammatory state can make blood sugar levels more challenging to control, potentially leading to the development or worsening of hyperglycemia, prediabetes, and overt type 2 diabetes.⁴ The inflammation associated with periodontal disease can decrease insulin sensitivity, thereby impairing glycemic regulation.¹⁰

The confirmed bidirectional relationship between diabetes and oral health indicates that oral health interventions are not merely supportive but are critical, integral components of comprehensive diabetes management. This understanding represents a significant shift in clinical thinking, elevating dental care to a primary therapeutic role. Evidence from various studies consistently demonstrates that effective periodontal treatment can lead to improvements in glycemic control, as indicated by reductions in glycosylated hemoglobin (HbA1c) levels.⁵ This direct impact means that neglecting oral health care in diabetic patients is not just neglecting their oral well-being; it actively undermines their systemic diabetes control. Therefore, integrating oral health into national health policies and non-communicable disease (NCD) programs ² is not just a recommendation for holistic care but an evidence-based strategy for more effective and potentially cost-efficient diabetes management, particularly vital in regions like Africa with limited resources and a high burden of both diseases.

2. Detailed Pathophysiology of Diabetes-Related Oral Complications

Diabetes mellitus contributes to a range of oral manifestations through complex systemic and local mechanisms. A thorough understanding of these pathophysiological pathways is essential for developing effective preventive strategies and targeted treatment modalities.

2.1. Periodontal Disease: Mechanisms of Susceptibility

Periodontal disease, characterized by infection and inflammation of the gums and the bone that support the teeth, is significantly more prevalent and severe in individuals with diabetes.⁶ This can lead to considerable discomfort, persistent bad breath, difficulties with chewing, and ultimately, tooth loss.⁶ The heightened susceptibility and accelerated progression of periodontitis in diabetic patients are attributed to a complex interplay of molecular and cellular mechanisms.

One primary mechanism involves an enhanced inflammatory response. Hyperglycemia, a hallmark of diabetes, directly induces a heightened inflammatory state within the periodontium.¹⁵ Studies have consistently shown that proinflammatory cytokines, such as interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6), are significantly elevated in the gingival tissue and crevicular fluid of diabetic periodontitis patients compared to systemically healthy individuals.¹⁶ Conversely, anti-inflammatory cytokines, including transforming growth factor-beta (TGF-β), IL-4, and IL-10, may exhibit decreased secretion, further exacerbating the inflammatory cascade.¹⁶ Adipokines, biologically active molecules secreted by adipose tissue, also play a crucial role. For instance, resistin, a proinflammatory adipokine, is found at higher levels in the serum and gingival crevicular fluid of periodontitis patients with type 2 diabetes, with these levels correlating positively with HbA1c values.¹⁶ In contrast, anti-inflammatory adiponectin levels are typically lower, while pro-inflammatory leptin levels are higher in these patients.¹⁶ This intricate molecular interplay of inflammatory mediators creates an environment highly conducive to tissue destruction.

Oxidative stress (OS) represents another critical factor in the pathogenesis of diabetic periodontitis. Hyperglycemia promotes the excessive production of Reactive Oxygen Species (ROS), leading to an imbalance between oxidants and antioxidants within periodontal tissues.¹⁵ This oxidative overload damages vital biomolecules such as proteins, lipids, and DNA, thereby accelerating periodontal tissue destruction. This overproduction of ROS occurs through multiple pathways, including the polyol, hexosamine, protein kinase C (PKC), and Advanced Glycation End Products (AGE)/Receptor for AGE (RAGE) pathways.¹⁶ The synergistic effect of ROS and the AGE/RAGE axes further contributes to exaggerated periodontal damage in diabetic individuals.¹⁶

Host immune factors are also profoundly affected by diabetes, impairing the body’s ability to effectively combat periodontal pathogens. Neutrophils, which are crucial components of innate immunity and form the first line of defense against periodontal bacteria, exhibit paradoxical behavior in diabetic periodontitis patients. While their numbers may be enhanced, their functional activities, including chemotaxis, phagocytosis, and bactericidal function, are impaired.⁷ This dysfunction can lead to increased intracellular killing and respiratory burst, which, paradoxically, exacerbates the severity of periodontitis by releasing excessive ROS and inflammatory mediators.¹⁶ Furthermore, diabetes can induce an imbalance in macrophage polarization, favoring the differentiation of pro-inflammatory M1 macrophages, which increases susceptibility and severity of periodontal disease, while reducing the number of anti-inflammatory M2 macrophages.¹⁶ An alteration in the Th17/Treg axis, a critical balance in adaptive immunity, also occurs, promoting the differentiation of initial CD4+ T cells into pro-inflammatory Th17 cells. The increased production of IL-17 from these Th17 cells can alter the pathogenicity of the periodontal microbiota, intensify inflammation, and lead to more severe periodontal bone loss.¹⁶

The composition of the oral microbiome is significantly influenced by systemic factors such as diabetes, which can increase the pathogenicity of the periodontal microbiota.¹⁵ Specific periodontal pathogens, including

Porphyromonas gingivalis and Tannerella forsythia, have been positively associated with type 2 diabetes and more severe periodontal disease.¹⁷ This dysbiosis contributes to the chronic inflammatory state.

Finally, diabetes directly contributes to alveolar bone resorption damage and epigenetic changes in periodontal tissue.¹⁰ The accumulation of AGEs can decrease the expression of osteoblast-related molecules and increase inflammation-related molecules, influencing bone metabolism.¹⁶ Epigenetic modifications, which alter gene expression without changing the underlying DNA sequence, may also play a role in promoting periodontitis in diabetic individuals.¹⁵

The intricate molecular and cellular pathophysiology underpinning diabetes-induced periodontal destruction reveals a systemic dysregulation encompassing immune cell dysfunction, metabolic pathway alterations (e.g., AGEs, ROS), and epigenetic modifications. This complex web of interactions creates a “perfect storm” for aggressive periodontal destruction in diabetic patients. This detailed understanding suggests that effective therapeutic strategies must extend beyond traditional mechanical debridement to include host modulation therapies that target these intricate systemic pathways, aiming to mitigate the fundamental biological changes that render the diabetic host more susceptible to severe periodontal disease.

2.2. Xerostomia (Dry Mouth): Etiology, Salivary Dysfunction, and Oral Health Impact

Xerostomia, commonly known as dry mouth, is a prevalent oral manifestation among diabetic patients, characterized by insufficient saliva production from the salivary glands to maintain oral moisture.⁶ Its estimated prevalence among individuals with diabetes ranges significantly, between 34% and 51%.⁷

The etiology of xerostomia in diabetes is multifactorial. It is often linked to polyuria (increased urination) and autonomic neuropathies that impair salivary gland function.⁷ Microvascular changes within the salivary glands and alterations in their basement membranes also contribute to reduced salivary flow.⁷ Critically, elevated blood glucose levels (hyperglycemia) directly contribute to the sensation of dry mouth, and certain medications prescribed for diabetes management can also induce xerostomia as a side effect.¹⁹ Kidney conditions, which can be a complication of long-term high blood glucose, may also lead to dry mouth.¹⁹

The symptoms of xerostomia extend beyond a mere dry sensation, often including mouth pain, a rough or dry tongue, and difficulties with eating, speaking, chewing, or swallowing.⁶ Patients may also experience sores or infections in the mouth, and an altered sense of taste.⁷ Other associated symptoms can include a sore throat, nasal dryness, and hoarseness.¹⁹

Saliva plays numerous crucial roles in maintaining oral health. It lubricates the oral cavity, facilitates the washing away of food debris, neutralizes acids produced by oral bacteria, provides essential minerals to teeth for remineralization, and actively combats microbes and their overgrowth that could lead to disease.¹⁹ The reduction in salivary flow and alterations in saliva composition due to xerostomia significantly impair these protective functions. This impairment creates an environment highly conducive to various oral problems, including increased susceptibility to dental caries, gingivitis, periodontitis, and oral thrush.⁶

Xerostomia functions as a central amplifying factor for a cascade of other oral complications in diabetic patients. Its presence not only causes considerable discomfort but fundamentally compromises the mouth’s natural defense mechanisms. This compromise directly accelerates the progression and severity of conditions such as dental caries, periodontal disease, and oral candidiasis. The direct causal link between reduced salivary protection and increased oral pathology underscores that managing xerostomia, whether through stringent glycemic control or symptomatic relief strategies like saliva stimulants, represents a critical upstream intervention that can significantly mitigate the risk and severity of multiple downstream oral health problems in individuals with diabetes.

2.3. Oral Candidiasis (Thrush): Fungal Overgrowth, Immune Compromise, and Species Diversity

Oral candidiasis, commonly known as oral thrush, is a fungal infection resulting from the overgrowth of Candida yeast, most frequently Candida albicans (C. albicans).⁶ Individuals with diabetes are particularly susceptible to developing oral thrush due to a combination of interconnected physiological factors.

A primary contributing factor is high blood sugar. Uncontrolled blood glucose levels create a sugar-rich environment within the oral cavity, which Candida species readily utilize as a nutrient source, thereby promoting their rapid proliferation.⁶ This hyperglycemic environment also enhances the production of hydrolytic enzymes by

Candida, such as secreted aspartyl proteinases (SAPs) and phospholipases (LPs). These enzymes are capable of degrading host tissues, including the basement membrane, extracellular matrix, and epithelial cell junctions, which not only enhances fungal invasion of the oral epithelium but also causes direct cytotoxicity and induces mucosal inflammation.²²

Furthermore, chronically elevated blood sugar can lead to a weakened immune system, making it more challenging for the body to mount an effective defense against fungal infections.²¹ Conditions often associated with diabetes, such as iron deficiency, can further compromise cellular immunity and antibody responses, contributing to a generalized reduction in immunity against infection.²² The presence of

dry mouth (xerostomia), as previously discussed, also disrupts the natural balance of microorganisms in the oral cavity, creating an even more favorable environment for Candida overgrowth.²¹

Symptoms of oral thrush typically include painful white patches on the tongue and inner cheeks, which may also appear on the roof of the mouth or gums.⁶ Patients often report redness, soreness, a burning sensation in the mouth, and difficulty swallowing or tasting.⁶ If left untreated, oral thrush can lead to severe complications, including the spread of the infection to other parts of the body, such as the bloodstream or upper gastrointestinal tract, potentially resulting in life-threatening systemic candidosis, particularly in immunocompromised patients.²¹

While C. albicans remains the most frequently isolated pathogen, there is an observable increase in the incidence of non-albicans Candida (NAC) species, such as C. glabrata, C. parapsilosis, C. tropicalis, and C. krusei, being isolated from oral lesions and the bloodstream.²² This shift carries significant clinical implications, as

C. krusei is intrinsically resistant to fluconazole, a common antifungal agent, and C. glabrata is increasingly demonstrating fluconazole resistance, posing considerable challenges for effective antifungal treatment.²² Moreover,

in vivo studies have indicated that increased glucose concentration can decrease the activity of antifungal agents, further complicating treatment outcomes.²²

The diabetic oral environment not only supports Candida proliferation but actively enhances its virulence and reduces the efficacy of antifungal treatments, creating a complex challenge exacerbated by the rise of drug-resistant non-albicans Candida species. This situation indicates that while antifungal medications are necessary for managing active infections, stringent glycemic control emerges as a primary “antifungal” strategy. By normalizing blood glucose levels, the oral microenvironment becomes less conducive to Candida growth and virulence, and the effectiveness of antifungal agents may be improved. This highlights the systemic nature of oral candidiasis in diabetic patients and the imperative for a holistic management approach to combat both the infection and the development of antifungal resistance.

2.4. Dental Caries: Altered Oral Environment and Increased Susceptibility

Diabetic patients exhibit a significantly heightened susceptibility to the development of both new and recurrent dental caries, commonly known as tooth decay.⁷ This increased risk is primarily a direct consequence of several interconnected factors that profoundly alter the oral environment in individuals with uncontrolled diabetes.

A major contributing factor is the reduced salivary cleansing and buffering capacity resulting from xerostomia. As previously discussed, diminished salivary flow and altered saliva composition impair the mouth’s natural ability to wash away food debris and neutralize the acids produced by oral bacteria.⁷ Saliva’s crucial role in maintaining a healthy pH balance and physically clearing food particles is compromised, allowing acids to persist on tooth surfaces for longer durations, leading to demineralization and cavity formation.

Furthermore, elevated blood glucose levels in individuals with uncontrolled diabetes can lead to an increase in sugar (glucose) levels within the saliva itself.⁶ This provides an abundant and readily available substrate for cariogenic bacteria, which metabolize these sugars to produce acids. The constant availability of glucose fuels the metabolic activity of these bacteria, leading to a sustained acidic environment that is highly detrimental to tooth enamel.

The altered oral environment, characterized by increased sugar availability and reduced salivary protection, also promotes a shift in the oral microbiota. This shift favors the proliferation of acid-producing bacteria, such as mutans streptococci and lactobacilli, as well as various oral yeasts, all of which are well-known contributors to tooth decay.⁷ These microorganisms thrive in the sugar-rich, acidic conditions, forming more aggressive biofilms (plaque) that further accelerate the demineralization process.

Beyond superficial decay, chronic hyperglycemia can also lead to more severe dental complications. It may cause irreversible pulpitis, an inflammation of the dental pulp, which can eventually result in pulp necrosis (death of the pulp tissue).⁷ Moreover, studies have indicated that periapical lesions, including apical periodontitis and radiolucent lesions around the tooth root apex, are more commonly observed in diabetic individuals compared to their non-diabetic counterparts.⁷

Dental caries in diabetic patients is thus a direct consequence of systemic metabolic dysregulation manifesting locally in the oral cavity. The interplay of altered salivary function, increased salivary glucose, and a shift towards a more cariogenic microbial population creates a highly favorable environment for rampant decay. This complex relationship reinforces the fundamental concept that oral health serves as a direct mirror of systemic health. Effectively preventing caries in diabetic individuals therefore requires not only diligent oral hygiene practices but also, and critically, stringent glycemic control to normalize the oral milieu and restore its natural protective mechanisms.

2.5. Impaired Oral Wound Healing and Other Manifestations

Delayed healing of both soft and hard tissues is a well-documented and significant complication in diabetic patients, particularly following oral surgeries or in the context of oral injuries.⁷ This impairment can substantially prolong recovery periods and significantly elevate the risk of post-operative complications, including infection and compromised surgical outcomes.

Multiple factors contribute to the prolonged and often suboptimal wound healing observed in diabetic individuals. These include delayed vascularization and diminished blood flow, which lead to localized hypoxia (insufficient oxygen supply) at the wound site.⁷ Furthermore, there is a

reduction in innate immunity and a decreased production of essential growth factors necessary for tissue repair and regeneration.⁷ Psychological stress, often associated with chronic disease management, can also negatively impact healing processes.⁷

At a more intricate cellular and molecular level, diabetes profoundly inhibits keratinocyte proliferation and migration, which are crucial for re-epithelialization, the process by which new skin or mucosal cells cover a wound.²³ The inflammatory response at the wound site is also altered, with chronic hyperglycemia and oxidative stress preventing the optimal expansion of

mesengenic cells, a type of mesenchymal stem cell crucial for connective tissue and bone formation.²³ Diabetes also leads to an elevation of pro-inflammatory cytokines and an inhibition of mitogenic growth factors, often mediated through

epigenetic mechanisms that alter gene expression patterns critical for healing.²³ This means that the very cellular machinery responsible for repair is compromised at a fundamental level.

Beyond wound healing, diabetes is associated with several other distinct oral manifestations:

• Burning Mouth Syndrome (Glossodynia): Patients may experience a persistent burning sensation or dysesthesia in the oral cavity.⁵ This symptom is often attributed to poor glycemic control, metabolic alterations within the oral mucosa, angiopathy (disease of blood vessels),
  Candida infection, and peripheral neuropathy affecting oral nerves.⁵
• Taste Dysfunction: Altered taste sensation (dysgeusia) or elevated taste detection thresholds can occur, particularly in individuals with poorly controlled diabetes.⁵ This dysfunction can be related to salivary abnormalities and neuropathy, and it may inadvertently inhibit a patient’s ability to maintain a healthy diet, thereby contributing to further poor glucose regulation.⁵
• Oral Mucosa Alterations: Various changes in the oral mucosa can be associated with diabetes, including conditions such as coated and fissured tongue, geographic tongue, recurrent aphthous stomatitis (canker sores), and certain premalignant lesions like oral lichen planus.⁷

The profound impairment of oral wound healing in diabetic patients stems from a complex, multi-level cellular and molecular dysfunction, including epigenetic changes and stem cell impairment. This indicates that relying solely on traditional wound care approaches is often insufficient for optimal outcomes. The complexity of this impairment necessitates the exploration of advanced biomaterial and targeted biological interventions. For example, novel biomimetic hydrogel adhesives have shown promise in diabetic rat models by effectively protecting mucosal wounds, significantly shortening the inflammatory phase, and promoting healing.²⁴ Similarly, exogenous application of bioactive factors such as epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) is being explored to stimulate cellular regeneration.²⁴ These advancements represent a significant research frontier for improving post-surgical outcomes and managing chronic oral lesions in diabetic populations.

---

Table 1: Common Oral Manifestations of Diabetes and Their Pathophysiological Links

Oral Manifestation	Key Pathophysiological Mechanisms	Key Symptoms/Impact	Relevant Citations
Periodontal Disease	Enhanced inflammatory response (↑ IL-1β, TNF-α, IL-6; ↓ anti-inflammatory cytokines; ↑ resistin, ↓ adiponectin, ↑ leptin); Oxidative stress (↑ ROS, AGE/RAGE pathways); Impaired host immune factors (neutrophil dysfunction, M1 macrophage polarization, Th17/Treg imbalance); Oral microbiome dysbiosis; Alveolar bone resorption, epigenetic changes.	Pain, persistent bad breath, swollen/bleeding gums, chewing difficulties, loose teeth, tooth loss, alveolar bone loss.	6
Xerostomia (Dry Mouth)	Polyuria, autonomic neuropathies, microvascular changes in salivary glands, hyperglycemia, side effect of diabetes medications, kidney conditions.	Frequent dry feeling, mouth pain, rough/dry tongue, difficulty eating/speaking/swallowing, sores, infections, altered taste, sore throat, hoarseness.	6
Oral Candidiasis (Thrush)	High blood sugar (Candida thrives on glucose, ↑ hydrolytic enzymes like SAPs/LPs, ↓ antifungal activity); Weakened immune system; Dry mouth.	Painful white patches (tongue, cheeks), redness, soreness, burning sensation, difficulty swallowing/tasting. Potential for systemic spread.	6
Dental Caries	Reduced salivary cleansing/buffering capacity (due to xerostomia); Increased salivary carbohydrate levels; Shift in oral microbiota (↑ mutans streptococci, lactobacilli, oral yeasts); Chronic hyperglycemia leading to pulpitis/necrosis.	Tooth decay (new & recurrent), irreversible pulpitis, pulp necrosis, apical periodontitis, periapical lesions.	6
Impaired Oral Wound Healing	Delayed vascularization, diminished blood flow/hypoxia; Reduced innate immunity; Decreased growth factor production; Psychological stress; Inhibited keratinocyte proliferation/migration; Altered inflammation; Reduced connective tissue/bone formation; Epigenetic mechanisms; Impaired mesengenic cell expansion.	Prolonged healing time, increased risk of post-operative complications/infection.	7
Other Manifestations	Poor glycemic control, metabolic alterations, angiopathy, Candida infection, neuropathy.	Burning mouth syndrome (glossodynia), taste dysfunction, coated/fissured tongue, geographic tongue, recurrent aphthous stomatitis, oral lichen planus.	5

---

3. Latest Clinical Trials and Research Breakthroughs

Significant advancements in clinical research and scientific understanding continue to refine approaches to managing diabetes-related oral complications. These breakthroughs span therapeutic interventions, diagnostic tools, and a deeper appreciation of microbial interactions.

3.1. Impact of Periodontal Therapy on Glycemic Control

A compelling body of evidence from recent clinical trials and large-scale studies consistently demonstrates that periodontal therapy can significantly influence systemic glycemic control in individuals with diabetes. This reinforces the bidirectional relationship between oral and systemic health.

Meta-analyses of various clinical trials have suggested a modest but clinically meaningful reduction in glycosylated hemoglobin (HbA1c) levels following periodontal treatment.¹² A notable investigation in this area is the Diabetes and Periodontal Therapy Trial (DPTT), a phase-III, multicenter, randomized controlled trial (ClinicalTrials.gov identifier: NCT00997178). This trial was specifically designed to determine whether comprehensive periodontal treatment could reduce HbA1c in patients with type 2 diabetes and chronic periodontitis.¹² The intervention, consisting of scaling and root planing combined with an antibacterial mouth rinse, showed a clear tendency towards improved glycemic control.

More recent real-world evidence further supports these findings. A large-scale claims database study from Japan, published in 2024, found that periodontal therapy improved glycemic control, particularly in individuals with baseline HbA1c levels of 7.0% or higher, demonstrating a statistically significant reduction.¹³ An earlier study in 2008 also reported that scaling and root planing, with or without adjunctive doxycycline, led to reductions in HbA1c (0.9% for scaling and root planing alone, and 1.5% with doxycycline) and a significant decrease in systemic inflammatory markers such as IL-6.¹⁴ These consistent findings, from rigorous clinical trials to large observational studies, empirically validate the positive impact of periodontal interventions on diabetes management.

Beyond direct treatment, longitudinal studies have also revealed a protective effect. Recovery from chronic periodontal disease has been associated with a lower risk for developing incident diabetes.²⁵ This suggests that maintaining periodontal health is not only crucial for managing existing diabetes but also plays a role in preventing its onset. The convergence of these findings from various study designs and populations underscores that periodontal therapy is a clinically relevant intervention for improving glycemic control in diabetic patients, thereby highlighting the imperative for its integration into routine diabetes management protocols.

---

Table 2: Summary of Key Clinical Trials on Periodontal Therapy and Glycemic Control

Study Name/Identifier	Study Design	Participants	Intervention	Primary Outcome (e.g., HbA1c change)	Key Findings	URL/DOI
DPTT (Diabetes and Periodontal Therapy Trial)	Phase III, Multicenter, Randomized Single-Masked Clinical Trial	600 participants with T2DM and chronic periodontitis	Immediate periodontal treatment (scaling and root planing + antibacterial mouth rinse) vs. delayed treatment (6 months).	Change in HbA1c from baseline to 6 months.	Periodontal treatment showed a tendency towards improved glycemic control. Trial powered to detect 0.6% HbA1c difference.	12
Japanese Claims Database Study (2024)	Weighted Cohort Analysis	4279 insured persons with T2DM	Periodontal therapy vs. no dental visits.	Change in HbA1c levels within a year.	Periodontal therapy tended to improve glycemic control. Significant HbA1c reduction (-0.094%) in those with baseline HbA1c 7.0%-7.9% who received therapy.	13
Iwamoto et al. (2008)	Double-masked, Placebo-controlled Study	30 subjects with T2DM and periodontitis	Scaling and root planing (SRP) + placebo (N=15) vs. SRP + doxycycline (100 mg/day for 14 days) (N=15).	Serum levels of HbA1c and inflammatory biomarkers.	Reduction in HbA1c (0.9% for SRP, 1.5% for SRP+Doxy) and significant reduction in inflammatory markers (IL-6, etc.).	14
Longitudinal PD Status Study (2022)	Longitudinal Cohort Study	111,611 subjects	Change in periodontal disease (PD) status over time (PD-free, PD-recovered, PD-developed, PD-chronic).	Occurrence of incident diabetes.	Recovery from chronic PD associated with lower risk for incident diabetes (adjusted HR 0.930).	25

---

3.2. Novel Therapeutic Approaches

The complex pathophysiology of diabetes-related oral complications has spurred the development of innovative therapeutic strategies that move beyond traditional symptomatic treatments to address underlying systemic dysregulations.

One promising area is Host Modulation Therapy (HMT). Low-dose doxycycline (Periostat®, 20 mg b.i.d) is the only HMT approved by the U.S. Food and Drug Administration (FDA) specifically for the treatment of periodontal disease.⁷ A 2017 publication in

Scientific Reports provided clinical rationale for its efficacy and safety in diabetic patients, demonstrating that doxycycline not only ameliorated insulin resistance, fasting blood glucose, insulin levels, and lipid profiles, but also improved islet morphology and enhanced glucose-stimulated insulin secretion.⁷ This indicates a dual benefit, addressing both periodontal inflammation and systemic metabolic parameters.

Another exciting development involves chemically-modified curcumins. A lead compound, chemically-modified curcumin 2.24 (CMC2.24), has shown significant promise as an adjunct to traditional local therapy. Its safety and efficacy have been demonstrated in vitro (in cell culture) and in vivo using various animal models, including mice, rats, rabbits, and dogs, for periodontal and other oral diseases.⁷ These host-modulation compounds represent a significant advancement, as they directly influence the host’s inflammatory and metabolic responses, offering a more targeted approach to managing the systemic components of oral disease in diabetic patients.

Regenerative medicine also holds potential for restoring damaged periodontal tissues in diabetic individuals. A case report highlighted the successful use of periodontal regenerative therapy with enamel matrix derivative in a 66-year-old man with generalized chronic periodontitis and type 2 diabetes, demonstrating improved periodontal conditions and a reduction in HbA1c levels.²⁷ This approach aims to rebuild the lost supporting structures of the teeth, offering a more definitive solution than merely halting disease progression.

Furthermore, gene therapy is an area of active research. While still largely experimental for oral complications, studies have explored its potential for type 1 diabetes, focusing on suppressing autoreactive T cells or replacing the insulin gene to normalize blood glucose levels.²⁸ More directly relevant to oral health, preliminary studies suggest that periodontal treatment can modulate the gene expression of endothelial progenitor cells in diabetic patients, leading to a notable reduction in immuno-inflammatory gene expression, specifically IL-6 and IL-8 transcripts.²⁹ This indicates a potential avenue for genetically targeted interventions to improve the inflammatory response in periodontal tissues.

The emergence of host modulation therapies, regenerative approaches, and gene-based interventions signifies a crucial shift towards targeted, molecular-level interventions. These therapies aim to address the underlying systemic dysregulations inherent in diabetic oral complications, moving beyond merely symptomatic treatment to fundamentally alter disease progression and promote true tissue regeneration.

3.3. Emerging Diagnostic Tools

The development of non-invasive and efficient diagnostic tools is crucial for early detection and continuous monitoring of diabetes and its oral complications, particularly in settings where traditional methods may be resource-intensive or inaccessible.

Salivary diagnostics represent a highly promising frontier in this regard. Saliva, a multifaceted biological fluid, contains a variety of molecular components, including proteins, enzymes, hormones, and metabolites, making it a dynamic indicator of both local oral and systemic health.³⁰ Studies have demonstrated that salivary glucose levels correlate well with blood glucose levels, indicating saliva’s potential for diagnosing and monitoring systemic conditions such as diabetes.³⁰

Recent research has focused on comparing the diagnostic effectiveness of various established inflammatory biomarkers for type 2 diabetes risk in both serum and saliva. A comprehensive review examined six such biomarkers: adiponectin, leptin, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and 1,5-anhydroglucitol (1,5-AG).³¹

For 1,5-Anhydroglucitol (1,5-AG), research has yielded consistent and promising results. Salivary 1,5-AG levels have been found to correlate positively with serum 1,5-AG and inversely with serum glucose and HbA1c.³¹ This consistency suggests that salivary 1,5-AG could potentially serve as a reliable biomarker for assessing type 2 diabetes risk and short-term glucose status, with implications for national screening programs.³¹ Similarly,

C-Reactive Protein (CRP), a sensitive biomarker of low-grade inflammation, has shown consistent correlations between salivary and serum concentrations.³⁰ Elevated salivary CRP levels have been observed in obese children and are associated with type 2 diabetes risk, indicating its potential as a non-invasive diagnostic marker.³¹

However, the utility of other biomarkers in saliva remains less consistent. While some studies suggest potential clinical relevance for salivary adiponectin, leptin, IL-6, and TNF-α, others report inconsistent findings, often attributed to heterogeneity in study design, participant characteristics, or methodological protocols.³¹

Despite the promising outlook, challenges persist in the widespread adoption of salivary diagnostics. The concentrations of molecular components in saliva are often exceptionally low, requiring highly sensitive analytical techniques.³¹ Furthermore, there is a critical need for standardization of saliva collection, processing, and analytical methods to reduce inconsistencies and errors across studies and facilitate their integration into routine clinical practice.³¹ Salivary diagnostics represent a non-invasive, cost-effective frontier for the early detection and monitoring of diabetes and its oral complications. This is particularly significant for widespread screening initiatives in resource-limited settings, where traditional blood-based diagnostics may be less feasible or accessible.

---

Table 3: Potential Salivary Biomarkers for Diabetes and Oral Health

Biomarker	Serum Findings	Saliva Findings	Consistency of Findings	Potential Clinical Utility/Challenges	Relevant Citations
Adiponectin	Low in overweight/obese, inversely correlated with visceral adiposity, associated with insulin resistance and T2DM.	Few studies; some positive correlation with plasma, but inconsistent on direct utility for metabolic syndrome prediction.	Inconsistent for direct salivary utility in T2DM risk prediction.	Non-invasive tool for diabetes risk, but more research needed for clinical utility and standardization.	31
Leptin	Elevated in obese, T2DM, metabolic syndrome patients.	Limited conclusive findings; some studies show higher in T2DM, others no difference in metabolic syndrome.	Inconsistent, potentially due to study heterogeneity.	Needs further exploration as a non-invasive biomarker, but not yet conclusive for metabolic syndrome prediction.	31
1,5-Anhydroglucitol (1,5-AG)	Decreased in T2DM due to glucosuria. Used for short-term glucose status.	Detectable; correlates with serum 1,5-AG, anti-correlates with serum glucose/HbA1c.	Consistent.	Promising for national screening programs for undiagnosed diabetes and predicting serum levels.	31
Interleukin-6 (IL-6)	Increased in T2DM patients; involved in dyslipidemia and hyperinsulinemia.	Highest in T2DM with periodontal disease; some correlation with serum.	Inconsistent, potentially overestimated by periodontitis.	Requires additional studies to confirm clinical utility.	31
C-Reactive Protein (CRP)	Elevated in T2DM; sensitive biomarker of low-grade inflammation.	Elevated in obese children; significant correlation with serum CRP.	Consistent.	Promising as a biomarker of T2DM risk.	30
Tumor Necrosis Factor-alpha (TNF-α)	Elevated in T2DM; associated with insulin resistance.	Some studies show higher in T2DM, others minimal differences.	Inconsistent.	More research needed to determine clinical utility.	31

---

3.4. Advances in Oral Microbiome Research and Probiotic Interventions

The oral cavity harbors a complex and dynamic microbial community, the composition of which is influenced by a multitude of factors, including host genetics, dietary habits, oral hygiene practices, medications, and systemic conditions like diabetes.¹⁸ Advances in culture-independent molecular methods have significantly broadened the understanding of these polymicrobial communities, revealing intricate networks of co-occurring microbes that contribute to oral health or disease.¹⁸

Recent research has explored the potential of modulating the oral microbiome as a therapeutic strategy, particularly through probiotic interventions. Oral probiotics, which introduce beneficial bacterial strains, can compete with periodontal pathogens in the formation of dental biofilm and are capable of modulating local and systemic immune responses.³²

Clinical studies have demonstrated the efficacy of probiotic therapy as an adjunct to conventional periodontal treatment in diabetic patients. For instance, probiotic administration has been shown to improve clinical periodontal parameters, such as bleeding on probing and probing depth, and to reduce the frequency of periodontopathogenic bacteria.³² Furthermore, these interventions have positively influenced oxidative stress markers and inflammatory cytokines (e.g., decreasing IL-8 and TNF-α while increasing IL-10).³² A double-blinded randomized controlled study specifically evaluated a combination of

Lactobacillus Reuteri strains in diabetic patients with gingivitis, finding it effective in reducing plaque index and bleeding on probing.³³

While the local oral health benefits of probiotics in diabetic patients with periodontal disease appear promising, the evidence regarding their direct impact on systemic glycemic control, as measured by HbA1c levels, remains uncertain and requires further investigation.³² Nevertheless, targeting the oral microbiome through probiotic interventions offers a novel, non-antibiotic strategy to manage periodontal disease in diabetic patients. This approach works by modulating local immunity and restoring microbial balance, providing an alternative or complementary method to traditional antimicrobial strategies. The continued elucidation of the oral microbiome’s role in systemic health holds significant promise for future therapeutic developments.

4. Addressing Oral Health Disparities in the African Context

The intersection of a rising diabetes burden and persistent oral health challenges creates significant disparities across the African continent. Understanding these unique challenges and the innovative interventions being explored is crucial for developing effective public health strategies.

4.1. Prevalence and Unique Challenges in Africa

Oral diseases continue to pose a substantial public health challenge in Africa, frequently being overlooked in national health agendas and universal health coverage frameworks.² As previously noted, the WHO African Region bears the highest global prevalence of severe periodontitis.² This high burden of oral disease exists in a context where diabetes prevalence is surging, with over half of affected individuals remaining undiagnosed and untreated.¹ This confluence of untreated systemic disease and prevalent oral pathology creates a complex health crisis.

Several unique challenges exacerbate these disparities:

• Workforce Shortages and Maldistribution: Africa faces a severe scarcity of oral health professionals. The dentist-to-population ratio in the WHO African Region is remarkably low, at just 0.44 per 10,000 population, significantly below international recommendations.² This shortage is compounded by an uneven distribution, with most dentists concentrated in urban centers, leaving vast rural communities underserved.² The “brain drain,” where trained professionals migrate abroad for better opportunities, further depletes the existing workforce.²
• Systemic Neglect and Policy Deficiencies: Oral health is often marginalized in the national health strategies of many African countries.² Public sector oral health services are frequently limited to emergency care and extractions, rather than comprehensive preventive or restorative treatments.² There is a pronounced lack of clear policies and strategic plans specifically aimed at improving oral healthcare systems.² This disconnect between oral and general health services is particularly problematic given that oral diseases share common risk factors with major non-communicable diseases (NCDs) like diabetes.²
• Educational Barriers and Financial Constraints: Limited training and capacity-building opportunities for healthcare professionals mean the workforce may not be adequately equipped to address the growing burden of oral diseases.² Furthermore, insufficient funding hinders the development of national oral health programs, restricts resource provision, and delays critical interventions. Reliance on external donors can lead to fragmented programs that are not fully aligned with local priorities, and inefficient resource allocation further undermines the potential for scaling up interventions.²
• Inadequate Infrastructure and Data Systems: Many African countries lack the necessary infrastructure and equipment for comprehensive oral health surveillance. Weak health information systems complicate data collection and analysis, making it difficult to identify trends, allocate resources effectively, and inform evidence-based policy development.² Logistical challenges, such as unreliable transportation, also disrupt the consistent delivery of essential oral health supplies to remote areas.²
• Limited Health Literacy: Studies, such as one conducted in Accra, Ghana, reveal that oral health knowledge and practices are significantly limited among patients with diabetes.³⁵ This lack of awareness about the interrelationship between diabetes and oral health contributes to minimal dental treatment utilization, often only in response to acute pain.³⁵

The confluence of a high disease burden, critical workforce shortages, systemic policy neglect, and limited health literacy creates a complex and reinforcing health crisis in Africa. Oral health disparities are deeply intertwined with broader health system weaknesses and socioeconomic factors. This situation indicates that solutions must be multi-pronged, addressing not only the immediate clinical needs but also the underlying systemic and community-level determinants of health.

4.2. Promising Interventions and Community-Based Strategies in African Settings

Despite the formidable challenges, various promising interventions and innovative community-based strategies are being explored and implemented across Africa to address oral health disparities in the context of diabetes. These approaches prioritize context-specific solutions and aim to strengthen health systems from the ground up.

A key strategy involves expanding dental education and promoting task-shifting. Strengthening dental education programs is crucial for increasing the overall number of oral health professionals. Concurrently, promoting task-shifting to mid-level workers, such as dental therapists and hygienists, can significantly help address workforce shortages and expand access to care, particularly in underserved regions.² Mozambique’s localized training initiatives, for example, have successfully enhanced the capacity of dental therapists and assistants.²

Mobile dental units have emerged as an accessible and cost-efficient alternative for delivering both curative and preventive oral healthcare, especially in remote and rural areas.² These units also serve as valuable training platforms for dental students, contributing to workforce development. Economic evaluations suggest that dental therapy-led models for mobile units could further reduce costs, making them a sustainable solution.²

Crucially, there is a growing emphasis on integrating oral health into national policies and non-communicable disease (NCD) programs.² This integration is essential to ensure dedicated funding, address rural-urban workforce disparities, and improve primary oral healthcare infrastructure, aligning with broader primary healthcare objectives and universal health coverage (UHC) frameworks.² The Africa Centers for Disease Control and Prevention (Africa CDC) has a pivotal role in advocating for this integration and providing technical assistance to member states.²

Community-based approaches and health literacy initiatives are vital for promoting preventive oral health. These include launching community programs that raise awareness about oral hygiene, healthy diets, and the importance of regular dental check-ups, often utilizing mobile dental health clinics where feasible.² Public health campaigns tailored to local social and cultural contexts can empower individuals to prioritize oral health.² For instance, a community-based strategy in Western Kenya, “Chamas for Change,” integrates preventive oral healthcare into broader maternal and child health programs, prioritizing community involvement, cultural sensitivity, and regular screenings.³⁷ This model demonstrates how culturally resonant, integrated approaches can address multiple health disparities simultaneously. Similarly, the South African diabetes prevention program (SA-DPP) pilot study highlights the effectiveness of community-based screenings for type 2 diabetes, emphasizing localized approaches.³⁸

Other promising interventions include leveraging Community-Led Monitoring (CLM) programs, particularly through Global Fund initiatives, to empower communities to monitor their oral health needs and advocate for better access to care.²

School-based programs are also being promoted to encourage children to adopt good oral health practices early on, integrating oral health education into existing school health curricula.²

Cross-border collaboration and knowledge sharing among African Union member states, facilitated by organizations like the Africa CDC, can foster collective learning and harmonize oral health strategies.² Finally,

resource mobilization and local production of essential oral health supplies are critical to improve availability and affordability on the continent.²

Specific examples of effective interventions in Sub-Saharan Africa include the provision of glucose machines with training, family support coupled with culturally tailored education, and direct periodontal treatment, all of which have shown notable improvements in adherence and reductions in HbA1c levels.³⁹ Telemedicine also presents a viable avenue to contribute to patient education and self-management of diabetes and its oral complications, particularly in geographically dispersed populations.⁴ These innovative, context-specific, and integrated community-based models, coupled with strategic policy shifts and workforce development, are essential for overcoming the unique oral health disparities in Africa and achieving broader health equity.

---

Table 4: Oral Health Challenges and Promising Interventions in Africa

Category	Specific Challenges	Promising Interventions	Relevant Citations
Workforce	Severe shortages (dentist-to-population ratio 0.44:10,000), maldistribution (urban concentration), “brain drain.”	Expanding dental education, task-shifting to mid-level workers (therapists, hygienists), localized training initiatives.	2
Policy & Governance	Systemic neglect of oral health in national agendas, limited public sector services (emergency/extractions), lack of clear policies.	Integrating oral health into national policies & NCD programs, Africa CDC advocacy/technical assistance.	2
Access & Infrastructure	Inadequate infrastructure for surveillance, weak health information systems, logistical challenges (transportation), limited pediatric services.	Mobile dental units, leveraging Community-Led Monitoring (CLM), school-based programs, cross-border collaboration.	2
Health Literacy & Awareness	Limited oral health knowledge among patients with diabetes, minimal dental treatment utilization (pain-driven).	Community-based approaches, culturally tailored health literacy campaigns, telemedicine for education/self-management.	4
Financial & Resources	Insufficient funding, fragmented programs due to donor reliance, inefficient resource allocation.	Resource mobilization, local production of essential oral health supplies.	2

---

5. Guidelines and Recommendations for Integrated Diabetes and Oral Health Care

The growing understanding of the bidirectional relationship between diabetes and oral health has led major international health organizations to issue comprehensive guidelines emphasizing the critical need for integrated care. These recommendations underscore that oral health is not merely an adjunct but an indispensable component of holistic diabetes management.

5.1. Perspectives from the American Diabetes Association (ADA) and International Diabetes Federation (IDF)

Both the American Diabetes Association (ADA) and the International Diabetes Federation (IDF) consistently advocate for proactive oral hygiene and professional dental care as integral components of diabetes management. Their guidelines reflect a global consensus on the importance of addressing oral health to improve overall well-being in individuals with diabetes.

The American Diabetes Association (ADA) highlights that individuals with diabetes are at a significantly higher risk for developing gum diseases such as gingivitis and periodontitis.⁸ This heightened risk is attributed to the amplified inflammatory response of the body to bacterial plaque when diabetes is not well-managed, which can lead to the destruction of supporting tissues around the teeth.⁸ Furthermore, dry mouth, a common oral condition in diabetic patients, can impede the natural cleansing action of saliva, allowing food debris, sugar, acids, and bacteria to accumulate more readily.⁸ To mitigate these risks, the ADA recommends several key steps for patients:

• Daily Oral Hygiene: Brushing teeth twice a day for two minutes with fluoride toothpaste is essential. The toothbrush should be angled at 45 degrees to the gums, using gentle back-and-forth motions to thoroughly clean all tooth surfaces. Soft bristles are advised to prevent enamel wear.⁸ Daily flossing is equally crucial to remove plaque and food particles from between teeth and along the gum line, thereby preventing tooth decay and gum disease.⁸ Interdental devices can be considered as an alternative for those who find traditional flossing challenging.⁸
• Regular Dental Visits: Patients should visit their dentist for routine check-ups at least twice a year. Depending on the health of their gums, more frequent cleanings, potentially every three months, may be recommended.⁸
• Proactive Engagement with Dental Professionals: The ADA advises patients to seek dentists who are knowledgeable about the specific oral health needs of individuals with diabetes.⁸ Patients are encouraged to be transparent with their dentist about their diabetes management status, as this information is crucial for guiding dental treatments and predicting treatment responses.⁸ Maintaining a normal eating and medication schedule prior to dental appointments is also recommended.⁸ Furthermore, patients should be proactive during their appointments, asking about gum health, any bleeding observed, and additional steps they can take for better oral care.⁸ A significant observation highlighted by the ADA is that dentists can play a vital role in identifying undiagnosed type 2 diabetes, with studies suggesting that nearly 1 in 5 individuals with severe gum disease may have undiagnosed diabetes, thus enabling referrals for screening.⁸

The International Diabetes Federation (IDF) similarly emphasizes that a healthy mouth is an integral part of overall well-being for people living with diabetes.¹¹ The IDF notes that high glucose levels contribute to oral health problems by fostering the growth of harmful bacteria, leading to delayed healing of oral wounds, and increasing susceptibility to oral thrush.¹¹ The IDF’s recommendations for patient care include:

• Annual Dental Visits: Regular annual dental visits are recommended to facilitate the early detection of gum disease symptoms, such as bleeding and swelling.¹¹
• Consistent Oral Hygiene: A thorough and consistent oral hygiene routine is paramount for preventing diabetes-related oral health complications. This routine should involve brushing teeth twice daily and cleaning between teeth at least once a day using dental floss, a special brush, or a wooden/plastic pick recommended by a dental professional. Floss holders, floss threaders, or water flossers are also suitable alternatives.¹¹
• Glycemic Control and Healthy Lifestyle: Effectively managing glucose levels is crucial, as this significantly reduces the risk of bacterial buildup that causes oral health complications.¹¹ Maintaining healthy lifestyle habits, including a balanced diet low in sugar and rich in fruits, vegetables, and whole grains, and engaging in regular physical activity, are also highly important.¹¹
• Smoking Cessation: Smoking is strongly linked to gum disease and other diabetes-related complications, further exacerbating oral health problems. Therefore, the IDF strongly advises smoking cessation for individuals with diabetes.¹¹

The consistent advocacy from both the ADA and IDF for proactive, routine oral hygiene and professional dental care as integral, not supplementary, components of diabetes management highlights a global consensus on the profound bidirectional link between oral and systemic health. This unified stance reinforces the scientific understanding that effective oral care is a fundamental pillar in achieving optimal diabetes control and improving the overall quality of life for affected individuals.

5.2. The Imperative of Interprofessional Collaboration

Effective management of diabetes and its associated oral complications necessitates a fundamental paradigm shift towards truly integrated, patient-centered, interprofessional care models. This approach moves beyond traditional siloed medical and dental practices to foster synergistic collaboration among healthcare providers.

The International Diabetes Federation (IDF) and the World Dental Federation (FDI) have jointly recognized this imperative, collaborating to develop formal recommendations on oral health and diabetes care.¹⁰ Their work underscores the critical need for improved communication and coordinated efforts between medical and dental professionals.¹⁰ A comprehensive care approach ensures that a patient’s oral health is well-managed while simultaneously enhancing the understanding of the intricate interplay between diabetes and oral health, thereby providing individuals with diabetes the holistic support necessary for their overall health and well-being.¹¹

The importance of this collaborative model is repeatedly emphasized in research. Proper and mutual referral between medical and dental practitioners is considered essential for optimal patient outcomes.⁵ Clinical trials, such as the Diabetes and Periodontal Therapy Trial (DPTT), exemplify this collaboration, with dental and medical researchers working together to recruit, treat, and monitor participants with both chronic diseases to assess the impact of treating one condition on the other.¹² Furthermore, case reports demonstrate that successful management of both periodontal and diabetic conditions often relies on close collaboration between the dentist and physician.²⁷

Studies conducted in African contexts further highlight the need for such integrated efforts. Research in Accra, Ghana, revealed limited oral health knowledge among diabetic patients and minimal dental utilization, suggesting that collaborative efforts for in-service education and training for both oral health and medical professionals would be highly beneficial.³⁵ Such initiatives would improve both the oral and general healthcare needs of Ghanaians with diabetes and enhance their oral health-related quality of life.³⁵

The recurring emphasis on interprofessional collaboration in various contexts indicates that the current healthcare system often lacks sufficient integration between medical and dental disciplines. This points to a need for systemic changes in how care is delivered, including policy and educational reforms that actively foster this collaboration. By breaking down professional silos and promoting a unified approach to patient care, healthcare providers can collectively achieve better patient outcomes, reduce the burden of diabetes-related complications, and significantly improve the quality of life for individuals living with these interconnected chronic conditions.

6. Conclusion

Diabetes mellitus and oral health are intricately linked through a complex bidirectional relationship, where each condition significantly influences the other. The global rise in diabetes prevalence, particularly pronounced and often undiagnosed in the African region, exacerbates the burden of oral diseases, which already present a substantial public health challenge on the continent. This interconnectedness creates a compounding health crisis, leading to higher rates of complications and premature mortality.

Detailed pathophysiological investigations reveal that hyperglycemia in diabetes drives a multifaceted cascade of events contributing to oral complications. These include an exaggerated inflammatory response, heightened oxidative stress, impaired immune cell function, and dysbiosis of the oral microbiome, all of which accelerate periodontal tissue destruction. Xerostomia acts as a central amplifying factor, compromising natural oral defenses and increasing susceptibility to dental caries and candidiasis. Furthermore, the diabetic oral environment not only promotes fungal overgrowth but also enhances Candida virulence and reduces antifungal efficacy, posing significant treatment challenges, especially with the emergence of drug-resistant strains. Impaired oral wound healing, stemming from profound cellular and molecular dysfunctions, further complicates dental care for diabetic patients.

Recent clinical trials and research breakthroughs offer promising avenues for improved management. Evidence consistently demonstrates that periodontal therapy can significantly improve glycemic control, underscoring its role as an integral component of diabetes management. Novel therapeutic approaches, such as host modulation therapies (e.g., low-dose doxycycline, chemically-modified curcumins) and regenerative techniques, are shifting treatment paradigms towards targeted, molecular-level interventions. Emerging salivary diagnostics provide a non-invasive, cost-effective tool for early detection and monitoring, holding particular promise for widespread screening. Advances in oral microbiome research and probiotic interventions also offer new strategies for managing periodontal disease by modulating local immunity and microbial balance

Works cited

1. Diabetes – WHO | Regional Office for Africa, accessed June 29, 2025, https://www.afro.who.int/health-topics/diabetes
2. Strengthening health systems to tackle oral diseases in Africa: Africa centers for disease control and prevention’s role – PubMed Central, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC11798923/
3. Diabetes and Oral Health: Summary of Current Scientific Evidence for Why Transdisciplinary Collaboration Is Needed – Frontiers, accessed June 29, 2025, https://www.frontiersin.org/journals/dental-medicine/articles/10.3389/fdmed.2021.709831/full
4. Oral Health Education in Patients with Diabetes: A Systematic Review – PMC, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC11083353/
5. Oral Health and Diabetes – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/33651538/
6. Diabetes and Oral Health Causes, Symptoms, Treatment, accessed June 29, 2025, https://www.nidcr.nih.gov/health-info/diabetes
7. Oral manifestations in patients with diabetes mellitus – PMC, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC6748880/
8. Oral Health and Diabetes | ADA – American Diabetes Association, accessed June 29, 2025, https://diabetes.org/health-wellness/keeping-your-mouth-healthy
9. Diabetes and dental health | MouthHealthy – Oral Health Information from the ADA, accessed June 29, 2025, https://www.mouthhealthy.org/all-topics-a-z/diabetes
10. Oral health – International Diabetes Federation, accessed June 29, 2025, https://idf.org/media/uploads/2023/05/attachments-52.pdf
11. Diabetes & Oral Health | International Diabetes Federation, accessed June 29, 2025, https://idf.org/about-diabetes/diabetes-complications/diabetes-and-oral-health/
12. a multicenter randomized single-masked clinical trial testing the effect of nonsurgical periodontal therapy on glycosylated hemoglobin (HbA1c) levels in subjects with type 2 diabetes and chronic periodontitis – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/24080100/
13. Effect of periodontal therapy on glycaemic control in type 2 diabetes – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/38171535/
14. Effects of periodontal therapy on glycemic control and inflammatory markers – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/18454655/
15. www.frontiersin.org, accessed June 29, 2025, https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2023.1192625/full#:~:text=The%20plausible%20pathogenic%20mechanisms%20of,damage%3B%20and%20(6)%20epigenetic
16. Diabetes mellitus promotes susceptibility to periodontitis—novel …, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC10469003/
17. Diabetes and periodontal disease: a case-control study – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/15857077/
18. The oral microbiome: Role of key organisms and complex networks in oral health and disease – PubMed Central, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC8457218/
19. Dry mouth and diabetes: Link, symptoms, and treatment – MedicalNewsToday, accessed June 29, 2025, https://www.medicalnewstoday.com/articles/dry-mouth-and-diabetes
20. Diabetes and Dry Mouth (Xerostomia): Symptoms, Causes, Treatment – Cleveland Clinic, accessed June 29, 2025, https://my.clevelandclinic.org/health/symptoms/22495-diabetes-and-dry-mouth
21. Diabetes and Oral Thrush: Symptoms, Causes, and Treatment Options – Smile Arizona Dentistry, accessed June 29, 2025, https://www.smilearizonadentistry.com/blog/diabetes-and-oral-thrush
22. Oral Candidosis: Pathophysiology and Best Practice for Diagnosis …, accessed June 29, 2025, https://www.mdpi.com/2309-608X/7/7/555
23. Diabetic Wound Healing in Soft and Hard Oral Tissues – PMC, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC8554709/
24. Acceleration of Oral Wound Healing under Diabetes Mellitus Conditions Using Bioadhesive Hydrogel – PMC, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC9837818/
25. Recovery from chronic periodontal disease is associated with lower risk for incident diabetes – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/35734903/
26. Diabetes, periodontal disease, and novel therapeutic approaches …, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/40099283/
27. Periodontal Regenerative Therapy in Patient with Chronic Periodontitis and Type 2 Diabetes Mellitus: A Case Report – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/27320299/
28. Gene therapy in diabetes – PMC – PubMed Central, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC3047781/
29. Periodontal treatment modulates gene expression of endothelial progenitor cells in diabetic patients – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/28836285/
30. Evaluation of Salivary Diagnostics: Applications, Benefits … – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/39958008/
31. The Clinical Utility of Salivary Biomarkers in the Identification of Type …, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC7553598/
32. Effectiveness of Probiotic Therapy in the Management of PeriodontalDisease in Diabetic Patients: A Scoping Review – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/38018184/
33. Oral probiotics in the management of gingivitis in diabetic patients: a double blinded randomized controlled study – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/28691473/
34. Disparities in Access to Oral Health Care – PMC – PubMed Central, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC7125002/
35. perceptions among adults with diabetes and oral/health care providers in Ghana – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/25300150/
36. Strengthening health systems to tackle oral diseases in Africa: Africa centers for disease control and prevention’s role – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/39916711/
37. Reducing maternal and child oral health disparities in Sub-Saharan …, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/39005710/
38. Findings from Community-Based Screenings for Type 2 Diabetes Mellitus in at Risk Communities in Cape Town, South Africa: A Pilot Study – PMC – PubMed Central, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC7215538/
39. Diabetes self-care intervention strategies and their effectiveness in Sub-Saharan Africa: A systematic review, accessed June 29, 2025, https://pmc.ncbi.nlm.nih.gov/articles/PMC11478876/
40. Oral Health Education in Patients with Diabetes: A Systematic Review – PubMed, accessed June 29, 2025, https://pubmed.ncbi.nlm.nih.gov/38727455/