INSR and periodontitis: It is generally accepted that periodontitis is more prevalent and severe in diabetics; thus, periodontal signs and symptoms are recognised as the ‘sixth complication’ of diabetes.21 The link between periodontitis and altered glycaemic control is still unclear, but it is believed that proinflammatory mediators expressed by periodontal sites enter the systemic circulation and affect the normal function of insulin receptors (suppression of signalling process), which in turn contributes to increased insulin resistance and impaired of glucose homeostasis.12