Page 10 - MDJ Volume 47 Number 2 ( Jul-Dec 2024)

Babu Osman, et al.: Oral microbiome in the elderly
in dental caries, challenging the previous focus on types: Type 1 diabetes (caused by autoimmune beta cell
Streptococcus mutans. The oral microbiota’s diversity destruction), Type 2 diabetes (characterised by insulin
influences the balance between health and disease, resistance and beta cell dysfunction), specific types of
linked to various oral and non-oral conditions. [10,11] NGS diabetes due to other causes (such as monogenic diabetes
enables detailed analysis of microbiome diversity and syndromes, diseases of the exocrine pancreas, or drug-
metagenomic activity, offering a deeper understanding of induced diabetes), and gestational diabetes (which occurs
the complex interactions within the oral microbiome. [12] during pregnancy). [24]

DM results from insulin production and action deficiencies,
[6]
trends of dental carIes In the elderly causing hyperglycaemia and metabolic abnormalities.
Dental caries in the elderly is influenced by multiple Risk factors include age, genetics, diet, physical activity and
risk factors, such as loss of periodontal attachment, smoking. Oral manifestations of DM include periodontal
past caries experience, high cariogenic bacterial load, disease, dry mouth, root caries, oral candidiasis, pulp
[25]
low socio-economic status, lack of awareness, diet, low necrosis, periodontal abscess and delayed wound healing.
salivary flow rate, increased salivary glucose level and
medical conditions and medications. [2,13,14] Periodontal rIsk factors for dental carIes In the elderly
disease or physiological gingival recession exposes the Periodontal disease and root caries
root surfaces of teeth, making them susceptible to root Periodontal disease can lead to gingival recession,
caries. [15-17] The dentine on the root surface demineralises exposing root surfaces to caries. Diabetes, particularly
[26]
faster than enamel due to its higher pH threshold for uncontrolled, is a common risk factor for both caries and
demineralisation. [18,19] periodontal diseases. There is a noted interplay between
[27]
Research by Kassebaum et al. indicates three peaks of periodontal disease and root caries, but evidence on the
caries development over a lifetime, with the third peak prevalence and risk factors remains limited.
occurring around age 70, marked by the appearance of
root caries. A systematic review and meta-analysis Systemic diseases
[20]
found an annual root caries incidence of 18.25% and Inflammatory oral diseases are linked to cardiovascular
[28]
[5]
an increment of 0.45 root decayed filled surfaces. A diseases and Type 2 DM (T2DM). Conditions such as
study in Bogotá, Colombia, found high rates of coronal arthritis or sarcopenia can impair oral hygiene, increasing
and root caries in geriatric institutions, associated with plaque formation and caries risk. Polypharmacy in older
individual risk factors. With increasing life expectancy adults reduces salivary flow, further increasing caries
[1]
and the retention of natural teeth, root caries is becoming susceptibility. [29,30] Diabetics, especially those with high
a significant public health issue. [21] levels of S. mutans and lactobacilli, are at higher risk of
[7]
dental caries. Studies show that improved oral health can
Caries development involves bacteria breaking down sugar enhance glycaemic control in diabetics. [9]
into organic acids, which demineralises the root surface
by removing calcium and phosphate ions. While enamel
demineralisation occurs at a pH of 5.5, root surfaces, Saliva
including cementum and dentine, begin to demineralise Diabetic elderly often have lower salivary pH and flow
at a higher pH of 6.4. High quantities of pathogenic rates, which are crucial for caries prevention. Several
[22]
bacteria and carbohydrate fermentation can disrupt the studies reported the effects of DM on the properties
[31,32]
balance between demineralisation and remineralisation, of saliva. Hyposalivation, common in older adults,
leading to caries. [23] lowers saliva’s buffering capacity, enhancing the
growth of cariogenic bacteria such as S. mutans and
Despite the prevalence of root caries in the elderly, Lactobacillus spp. [33-37]
systematic reviews reveal that less than one-third of
[4]
studies report on root caries status. More research is Fluoride
needed to understand the prevalence and specifics of root Fluoride treatments are effective in preventing dental
caries in older adults to develop effective prevention and caries. Recent studies show that silver diamine fluoride
[38]
treatment strategies. (SDF) and high-fluoride toothpaste are effective for
treating root caries in the elderly. Sodium fluoride
[39]
varnish, SDF solution and acidulated phosphate fluoride
dIabetes MellItus and dental carIes
gel are all effective in preventing root caries. [40-42]
Diabetes is a chronic condition that significantly impacts
[6]
global healthcare. The International Diabetes Federation
reported a global diabetes prevalence of 9% (463 million oral MIcrobIoMe and dental carIes
adults) in 2019, primarily due to population ageing. The gut microbiota is known to be associated with health
[43]
According to Sun et al. (2021), DM is classified into four and disease in humans. Alterations in this microbiota

36 Malaysian Dental Journal ¦ Volume 47 ¦ Issue 2 ¦ July-December 2024
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