Influence of saliva on the results of global laboratory coagulation tests.

BACKGROUND: Oral wounds inevitably come into contact with saliva which can affect the time needed for bleeding to stop. The influence of saliva can be non-specific, related to dilution of blood, and/or mediated by salivary factors that affect haemostasis directly. The aim of this study was to assess if mixing blood with an individual's saliva would affect the rate of its coagulation measured by global coagulation tests, prothrombin time (PT) and activated partial thromboplastin time (APTT). METHODS: The study included 30 healthy non-smoking volunteers. Paired blood and unstimulated saliva samples were obtained from each participant and PT and APTT were determined in blood, blood + saliva and blood + water mixtures. Coagulation tests were performed using the mechanical clot detection method. RESULTS: PT was significantly longer in both blood + saliva and blood + water mixtures compared to blood alone. APTT was significantly longer only in blood + water mixture compared to blood. CONCLUSIONS: Similarly prolonged PT in both mixtures suggests that both saliva and water prolong coagulation evenly due to their non-specific effect of blood dilution. The finding that APTT was significantly prolonged only when blood was mixed with water could indicate presence of tissue factor in saliva, however, in a concentration too low to influence the results of PT.

Changes in salivary oxidative status, salivary cortisol, and clinical symptoms in female patients with temporomandibular disorders during occlusal splint therapy: a 3-month follow up.

BACKGROUND: Differences in the expression of oxidative stress (OS) markers between female patients with temporomandibular disorders (TMD) and healthy individuals indicate that OS plays a role in the pathogenesis of TMD. Because chronic exposure to stress generates oxidative damage during continuous stimulation of the hypothalamic-pituitary-adrenal axis, we expected that higher levels of cortisol might be associated with higher oxidative damage. Our aim was to test the association between OS markers, stress perception, and salivary cortisol (SC) in chronic, female TMD patients. We tracked changes in OS markers and SC during occlusal splint therapy in order to evaluate the influence of treatment on oxidative status. We hypothesized that the effects of TMD therapy would differ among individuals depending on the source and intensity of pain. METHODS: Sixteen female patients were recruited, and 12 finished the study. Clinical assessment and saliva sampling were performed at the baseline and follow-up appointments. Repeated measures analysis of variance and Pearson's correlation were used for analyzing the data. RESULTS: After 3 months, a significant reduction in afternoon total antioxidant capacity (TAC) was observed (p < 0.05). A significant reduction in afternoon malondialdehyde (MDA) (p = 0.021) and a decrease in afternoon MDA to superoxide dismutase ratios (p = 0.017) were present in high-intensity pain patients. At baseline, higher levels of perceived stress were significantly associated with higher morning cortisol (ρ = 0.67). At the end of the therapy,  reduced  perceived stress was positively correlated with morning SC changes when considering all TMD patients, but the association between perceived stress with OS markers was present only in myofascial pain (MP) group. The effect of treatment on the self-perceived quality of life was more pronounced in female MP patients while the reduction of spontaneous pain was significantly greater in high-intensity pain patients. CONCLUSION: Our data indicate that occlusal splint therapy in female TMD patients contributes to increasing their capacity to remove free radicals. The question remains whether or not TAC decreases in this process as a result of avoiding unnecessary processes, once the increase in antioxidants effectively compensates for OS. The intensity and the source of pain should be considered important factors in future investigations evaluating salivary OS markers and their association with perceived stress and SC in TMD patients. TRIAL REGISTRATION: ClinicalTrials.gov NCT03029494 . Registered on 2017-01-19.