The Link Between Dental and Heart Diseases: A Potential New Treatment For Periodontitis

With an aging population and high rates of cardiovascular disease, research into the causes and possible treatments is of utmost importance. There are various causes of heart related conditions, including poor diet, obesity and diabetes, just to name a few, but over the years, researchers have discovered a link between heart related conditions and poor dental health _[1]. This interlink is supported by research in older people in the UK and USA, which shows that predispositions such as the factors listed above are highly associated with poor dental health _[1]. Findings indicate that poor oral health, including tooth loss and dry mouth, is associated with all-cause mortality _[1]. More specifically, medical reviews have shown that there is robust evidence to support the link between chronic periodontitis and atherosclerotic heart disease, with possible causes of this being periodontal pathogens, vascular endothelial damage and atherogenesis _[2].

Periodontitis is a type of severe gum disease characterised by red, swollen and bleeding gums, which originates in the gingival tissue _[3]. Whilst this disease has multiple causes, the main culprit is the complex biofilm that grows on the teeth in dental plaque _[2]. The complex dental biofilm is made up of an initial layer which homes bacteria including Streptococcus and Actinomyces followed by gradual deposition of other microbes, resulting in a microenvironment with reduced oxygen, thus allowing colonisation of anaerobes such as Fusobacterium, which is considered a “bridging” species in the development of gum disease _[3].  The shift to anaerobic conditions and further colonization by other anaerobes commences the progression of gingivitis to periodontitis, which triggers the host immune response, leading to the symptoms associated with this disease, including swelling and redness _[3]. Periodontitis therapy mainly targets improving gingival health but due to poor patient compliance, non-surgical subgingival scaling is commonly compromised, so researchers are keen on investigating an efficient local drug administrative approach, including the use of hydrogels _[4].

Dong et al. studied the effectiveness of gelatin-oxidized dextran hydrogel loaded with calcium peroxide and penicillin (CP-P hydrogel) in treating the symptoms caused by periodontitis _[4]. One part of the study aimed to assess the antibacterial activity of the composite hydrogel on the Gram-negative anaerobic periodontal pathogen Porphyromonas gingivalis by measuring the optical density medium inoculated with the bacterium; incubation of the bacterium was done in a Whitley A35 Workstation _[4]. Another aspect of the study included injecting the hydrogel into the periodontal pocket to achieve gradual release of the antibiotics and oxygen to promote antibacterial activity and lower bacterial resistance to antibiotic drugs _[4]. Against P. gingivalis, the hydrogel was found to bacteriostatic effects _[4]. Through injection into the periodontal pocket, the hydrogel had excellent mechanical properties, lowered swelling and had sufficient biocompatibility, and by injecting into this pocket, the drug was able to target the anaerobic environment, subsequently making it a less favourable setting for anaerobic growth _[4]. All in all, this means that the microbial growth associated with periodontitis will be reduced, supporting the use of CP-P hydrogel as a therapeutic treatment _[4]. 

Research of this kind gives promise to a new successful treatment of periodontal disease, and in turn heart disease, due to the strong association between them. Hopefully, scientists will continue this research and reduce mortality of patients and the burden on healthcare services.

References

1. Kotronia E, Brown H, Papacosta AO, Lennon LT, Weyant RJ, Whincup PH, et al. Oral health and all-cause, cardiovascular disease, and respiratory mortality in older people in the UK and USA. Scientific Reports [Internet]. 2021 Aug 12;11(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8361186/
2. Dietrich T, Webb I, Stenhouse L, Pattni A, Ready D, Wanyonyi KL, et al. Evidence summary: the relationship between oral and cardiovascular disease. British Dental Journal. 2017 Mar;222(5):381–5.
3. Mehrotra N, Singh S. Periodontitis. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK541126/
4. Dong S, Mei Y, Zhang Y, Bu W, Zhang Y, Sun C, et al. A Novel Therapeutic Calcium Peroxide Loaded Injectable Bio-adhesive Hydrogel Against Periodontitis. International Dental Journal. 2024 Aug 1.