Gaetano Isola

The skin, oral cavity, digestive and reproductive tracts of the human body harbor symbiotic and commensal microorganisms living harmoniously with the host. The oral cavity houses one of the most heterogeneous microbial communities found in the human organism, ranking second in terms of species diversity and complexity only to the gastrointestinal microbiota and including bacteria, archaea, fungi, and viruses. The accumulation of microbial plaque in the oral cavity may lead, in susceptible individuals, to a complex host-mediated inflammatory and immune response representing the primary etiological factor of periodontal damage that occurs in periodontitis. Periodontal disease is a chronic inflammatory condition affecting about 20-50% of people worldwide and manifesting clinically through the detection of gingival inflammation, clinical attachment loss (CAL), radiographic assessed resorption of alveolar bone, periodontal pockets, gingival bleeding upon probing, teeth mobility and their potential loss in advanced stages. This review will evaluate the changes characterizing the oral microbiota in healthy periodontal tissues and those affected by periodontal disease through the evidence present in the literature. An important focus will be placed on the immediate and future impact of these changes on the modulation of the dysbiotic oral microbiome and clinical management of periodontal disease.

BACKGROUND: The WHO Global Oral Health Action Plan has set an overarching global target of achieving a 10% reduction in the prevalence of oral conditions by 2030. Robust and up-to-date information on the global burden of oral conditions is paramount to monitor progress towards this target. The aim of this systematic data analysis was to produce global, WHO region, and country-level estimates of the prevalence of, and disability-adjusted life-years (DALYs) attributed to, untreated caries, severe periodontitis, edentulism, other oral disorders, lip and oral cavity cancer, and orofacial clefts from 1990 to 2021. METHODS: This report is based on the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021. Input data were extracted from epidemiological surveys, population-based registries, and vital statistics. Data were modelled with DisMod-MR 2.1, a Bayesian meta-regression modelling tool, to ensure consistency between prevalence, incidence, remission, and mortality estimates for oral conditions. DALYs were estimated as the aggregation of the years of life lost (YLLs) due to premature mortality and years lived with disability (YLDs). YLDs were calculated by multiplying prevalence estimates, the severity of the oral condition's sequelae (disability weight) and duration of the sequelae. Although all oral conditions lead to YLDs, only lip and oral cavity cancer and orofacial clefts lead to YLLs as well. 95% uncertainty intervals (UIs) were generated for every metric with the 25th and 975th ordered 1000 draw values of the posterior distribution. FINDINGS: The combined global age-standardised prevalence of the main oral conditions (untreated caries, severe periodontitis, edentulism, and other oral disorders) was 45 900 (95% UI 42 300 to 49 800) per 100 000 population in 2021, with 3·69 billion (3·40 to 4·00) people affected globally. Untreated dental caries of permanent teeth and severe periodontitis were the most common oral conditions, with a global age-standardised prevalence of 27 500 (24 000 to 32 000) per 100 000 population and 12 500 (10 500 to 14 500) per 100 000 population, respectively. Edentulism, severe periodontitis, and lip and oral cavity cancer caused the highest burden as demonstrated by their counts of DALYs and age-standardised DALY rates. Existing trends for 1990-2021 reveal relatively small changes (upward or downward) in prevalence and burden. Increasing counts of prevalent cases and DALYs were noted for all oral conditions but untreated caries of deciduous teeth (no percentage change in prevalence or DALYs) and orofacial clefts (-68·3% [-79·3 to -46·5] decrease in DALYs). There were decreases in both age-standardised prevalence and DALY rate for untreated caries of permanent teeth and edentulism, no change in both for untreated caries of deciduous teeth and severe periodontitis, an increase in the prevalence but no change in the DALY rate for lip and oral cavity cancer, and no change in the prevalence but a decrease in the DALY rate for orofacial clefts. By WHO region, the African and Eastern Mediterranean regions showed the largest increases in prevalent cases and DALYs for most oral conditions, while the European region showed the smallest increases or no change. The European region was the only region with decreasing age-standardised prevalence of untreated caries in both deciduous (-9·88%; -12·6 to -6·71) and permanent teeth (-5·94% (-8·38 to -3·62). The prevalence and DALY rate of severe periodontitis decreased in the African region, while the prevalence and DALY rate of edentulism decreased in the African region, South-East Asia region, and Western Pacific region. Furthermore, DALY rates of lip and oral cavity cancer decreased in the European region and the region of the Americas, while DALY rates of orofacial clefts decreased in all regions. INTERPRETATION: The minor changes in the burden of oral conditions over the past 30 years demonstrate that past and current efforts to control oral conditions have not been successful and that different approaches are needed. Many countries now face the double challenge of controlling the occurrence of new cases of oral conditions and addressing the huge unmet need for oral health care. FUNDING: Bill & Melinda Gates Foundation.

Over the last few decades, studies on the oral microbiome have increased awareness that the balance between the host and the microbial species that coexist in it is essential for oral health at all stages of life. However, this balance is extremely difficult to maintain, and many factors can disrupt it: general eating habits, sugar consumption, tobacco smoking, oral hygiene, and use of antibiotics and other antimicrobials. It is now known that alterations in the oral microbiota are responsible for developing and promoting many oral diseases, including periodontal disease. In this context, diet is an area for further investigation as it has been observed that the intake of particular foods, such as farmed animal meat, dairy products, refined vegetable oils, and processed cereals, affects the composition of the microbiota, leading to an increased representation of acid-producing and acid-tolerant organisms and periodontal pathogens. However, little is known about the influence of diet on the oral microbiome and the creation of a suitable microenvironment for the development of periodontal disease. The aim of the present study is to evaluate current knowledge on the role of diet in the oral dysbiosis underlying periodontal disease.

BACKGROUND AND OBJECTIVE: Vitamin D has been considered to possess anti-inflammatory and antimicrobial activity, which may be a link for the known interaction of periodontitis (CP) and coronary heart disease (CHD). This study investigated the association between serum vitamin D levels and periodontitis in patients with CP and with CHD. Furthermore, the objective was to determine whether periodontitis and CHD had an impact on serum vitamin D levels. MATERIAL AND METHODS: Using a cross-sectional design, a total of 46 patients with CP, 45 patients with CHD, 45 patients with both CP and CHD, and 43 healthy patients were enrolled in the present study. RESULTS: Patients in the CP (17.4 ± 5.2 ng/mL) and in the CP + CHD (16.5 ± 5.6 ng/mL) group presented a significantly lower mean serum level of 25(OH)vitamin D compared to patients in the CHD (24.6 ± 3.7 ng/mL) and healthy control groups (29.9 ± 5.4 ng/mL) (P < .001). 25(OH)vitamin D levels were positively correlated with the number of teeth and negatively with C-reactive protein (CRP) and all periodontal parameters (P < .001). In all patients, there was a proportional increase of 25(OH)vitamin D levels with a progressive increase in number of teeth (P-trend <.001) while there were a proportional decrease in 25(OH)vitamin D levels with a progressive increase in clinical attachment level (CAL, P-trend = .001), probing depth (PD, P-trend = .006), and bleeding sites (BOP, P-trend <.001) levels. CONCLUSION: Patients with CP and CP + CHD presented significantly lower serum levels of vitamin D compared to CHD and healthy controls. Moreover, the presence of CP negatively influenced serum vitamin D levels.

During recent years, considerable progress has been made in understanding the etiopathogenesis of periodontitis in its various forms and their interactions with the host. Furthermore, a number of reports have highlighted the importance of oral health and disease in systemic conditions, especially cardiovascular diseases and diabetes. In this regard, research has attempted to explain the role of periodontitis in promoting alteration in distant sites and organs. Recently, DNA sequencing studies have revealed how oral infections can occur in distant sites such as the colon, reproductive tissues, metabolic diseases, and atheromas. The objective of this review is to describe and update the emerging evidence and knowledge regarding the association between periodontitis and systemic disease and to analyse the evidence that has reported periodontitis as a risk factor for the development of various forms of systemic diseases in order to provide a better understanding of the possible shared etiopathogenetic pathways between periodontitis and the different forms of systemic diseases.