Salivary antioxidants as periodontal biomarkers in evaluation of tissue status and treatment outcome

<jats:sec><jats:title>Background and objective</jats:title><jats:p>One of the major pathologic patterns in periodontitis represents an imbalance among the production of free radicals and local antioxidants resulting in periodontal tissue destruction. The objective of the study was to investigate the influence of non‐surgical periodontal treatment on salivary antioxidants and to evaluate their capacity as biomarkers reflecting periodontal tissue condition and therapy outcome.</jats:p></jats:sec><jats:sec><jats:title>Material and Methods</jats:title><jats:p>Sixty‐three systemically healthy non‐smokers, including 21 periodontally healthy subjects (<jats:styled-content style="fixed-case">HC</jats:styled-content>) and 42 patients with current chronic periodontitis fulfilled the inclusion criteria. Half of the patients received scaling and root planing (<jats:styled-content style="fixed-case">SRP</jats:styled-content>) and the other half received only oral hygiene instructions. Full mouth clinical measurements, including gingival index (<jats:styled-content style="fixed-case">GI</jats:styled-content>), plaque index (<jats:styled-content style="fixed-case">PI</jats:styled-content>), periodontal pocket depth, clinical attachment level and saliva sampling were performed at baseline visit and 2 mo after treatment/baseline visit. Total antioxidant capacity (<jats:styled-content style="fixed-case">TAOC</jats:styled-content>), albumins (<jats:styled-content style="fixed-case">ALB</jats:styled-content>), uric acid (<jats:styled-content style="fixed-case">UA</jats:styled-content>), superoxide dismutase (<jats:styled-content style="fixed-case">SOD</jats:styled-content>) and glutathione peroxidase (<jats:styled-content style="fixed-case">GPX</jats:styled-content>) were evaluated in saliva samples using commercial kits.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>All measured antioxidants were affected by treatment resulting in significant increase in <jats:styled-content style="fixed-case">TAOC</jats:styled-content> (<jats:italic>p</jats:italic> < 0.005), <jats:styled-content style="fixed-case">ALB</jats:styled-content> (<jats:italic>p</jats:italic> < 0.001), <jats:styled-content style="fixed-case">UA</jats:styled-content> (<jats:italic>p</jats:italic> < 0.001) and <jats:styled-content style="fixed-case">GPX</jats:styled-content> (<jats:italic>p</jats:italic> < 0.001) and decrease of <jats:styled-content style="fixed-case">SOD</jats:styled-content> (<jats:italic>p</jats:italic> < 0.005) in response to <jats:styled-content style="fixed-case">SRP</jats:styled-content>, where no differences were observed for any of parameters in the oral hygiene instructions group. Comparison of antioxidant levels between the <jats:styled-content style="fixed-case">HC</jats:styled-content> and <jats:styled-content style="fixed-case">SRP</jats:styled-content> group showed that before treatment <jats:styled-content style="fixed-case">ALB</jats:styled-content> were significantly higher in <jats:styled-content style="fixed-case">HC</jats:styled-content> when compared to the <jats:styled-content style="fixed-case">SRP</jats:styled-content> group (<jats:italic>p</jats:italic> = 0.039), and <jats:styled-content style="fixed-case">GXP</jats:styled-content> (<jats:italic>p</jats:italic> = 0.000) and <jats:styled-content style="fixed-case">SOD</jats:styled-content> (<jats:italic>p</jats:italic> = 0.021) levels were significantly higher in the <jats:styled-content style="fixed-case">SRP</jats:styled-content> group. Comparison of values after treatment showed that <jats:styled-content style="fixed-case">TAOC</jats:styled-content> was significantly higher in the <jats:styled-content style="fixed-case">HC</jats:styled-content> than in the <jats:styled-content style="fixed-case">SRP</jats:styled-content> group (<jats:italic>p</jats:italic> = 0.001), but <jats:styled-content style="fixed-case">UA</jats:styled-content> was, inversely, significantly higher in the <jats:styled-content style="fixed-case">SRP</jats:styled-content> group (<jats:italic>p</jats:italic> = 0.034). All clinical parameters except clinical attachment level were significantly decreased after <jats:styled-content style="fixed-case">SRP</jats:styled-content> and significant correlations were observed between <jats:styled-content style="fixed-case">SOD</jats:styled-content> and <jats:styled-content style="fixed-case">GI</jats:styled-content> (<jats:italic>p</jats:italic> = 0.017), <jats:styled-content style="fixed-case">SOD</jats:styled-content> and <jats:styled-content style="fixed-case">PI</jats:styled-content> (<jats:italic>p</jats:italic> = 0.011), <jats:styled-content style="fixed-case">GPX</jats:styled-content> and <jats:styled-content style="fixed-case">GI</jats:styled-content> (<jats:italic>p</jats:italic> = 0.003) and <jats:styled-content style="fixed-case">GPX</jats:styled-content> and <jats:styled-content style="fixed-case">PI</jats:styled-content> (<jats:italic>p</jats:italic> = 0.008).</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Non‐surgical periodontal treatment affected salivary <jats:styled-content style="fixed-case">TAOC</jats:styled-content>,<jats:styled-content style="fixed-case"> ALB</jats:styled-content>,<jats:styled-content style="fixed-case"> UA</jats:styled-content>,<jats:styled-content style="fixed-case"> SOD</jats:styled-content> and <jats:styled-content style="fixed-case">GPX</jats:styled-content>; moreover, these biochemical parameters convincingly reflected periodontal status and tissue response on treatment.</jats:p></jats:sec>