**5. Periodontal therapy and cardiovascular risk**

Non-surgical treatment of periodontitis refers to subgingival instrumentation of periodontally affected teeth and addresses the polymicrobial aetiologic factor from the subgingival areas. Full-mouth subgingival instrumentation performed within 24 hours has been proposed to prevent the dissemination of bacteria from non-instrumented pockets to the previously treated areas [62]. It is also worth mentioning that in severe generalized periodontitis, due to the mobilization of a huge mass of bacteria from the periodontal pockets, the full-mouth instrumentation could trigger an acute systemic inflammatory response associated with transient endothelial dysfunction [63]. Delivering subgingival instrumentation conventionally in several short sessions could overcome the systemic response and the theoretical short-term risk of developing a vascular event [64].

Data from observational studies observed no effect or just a minimal elevated risk of "*invasive dental treatment"* [65, 66] in augmenting the ischaemic cardiovascular risk. The report concluding that the "*invasive dental treatment"* had no effect in increasing the risk of myocardial infarction was based on the *Taiwanese National Health Insurance Research Database* and included more than 110,000 myocardial infarction patients and 290,000 ischaemic stroke patients over a period of 14 years. However, a modest risk of myocardial infarction during the first week after treatments has been indicated (OR = 1.31, 95% CI [1.08; 1.58], after 3 days). A selfcontrolled case series on about 10 million persons from an US insurance database reported that "*invasive"* dental treatments, mostly represented by tooth extractions, were associated with an augmented risk of incident acute cardiovascular events (IR = 1.5, 95% CI [1.09; 2.06]) within 1 month after therapy [66]. A small-scale clinical trial reported no cardiovascular adverse events within 3 months after periodontal subgingival instrumentation in patients with established CVD [67]. Also, a randomized secondary prevention trial showed that subgingival instrumentation in patients with established CVD was not associated with an increased incidence of cardiovascular events in 6 months after periodontitis treatment [68]. Moreover, a study on 5297 subjects, with a median follow-up period of 16.8 years concluded that individuals who did not respond well to periodontal treatment had a 28% increased risk for future CVD, indicating that successful periodontal treatment might influence the progression of subclinical CVD [69].

However, nowadays conclusions on this topic sustain that no association between "*invasive"* periodontal treatments and an increased incidence of myocardial infarction or ischaemic cardiovascular risk has been reported [8, 70].
