title: Effects of composite restorations on nitric oxide and uric acid levels in saliva.
abstract: OBJECTIVE
  Dental materials that are used in dentistry should be harmless to oral tissues, and should, therefore, not contain any leachable toxic and diffusible substances capable of causing side effects. This study was intended to investigate the effects on salivary nitric oxide (NO) and uric acid (UA) levels after application of dental composite filling materials to healthy volunteers.
  
  
  METHODS
  A total of 52 individuals (32 female and 20 male) participated in the study. Filtek Z250 composite filling material (3M ESPE, St Paul, MN, USA) was applied to healthy volunteers. Saliva samples were collected before restoration (baseline) and 1 h, 1-day, 7 days, and 30 days after restoration. NO concentrations were measured using the Griess reaction method, and UA was measured using an enzymatic method. Data were analyzed using repeated measures ANOVA and the Bonferroni post-hoc test (α =5%).
  
  
  RESULTS
  NO values increased statistically significant after 7 days (P < 0.05). In addition, lower UA levels were determined compared to the baseline levels, but the difference was not statistically significant (P > 0.05). There was no correlation between NO and UA levels in saliva (P > 0.05).
  
  
  CONCLUSIONS
  Composite resins activated the antioxidant system in saliva. However, further studies are now needed to confirm our findings and to permit a definitive conclusion.
authors: Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University, Erzurum, 25240, Turkey.
authors: Nilgun
authors: N
authors: Akgul
authors: Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University, Erzurum, 25240, Turkey.
authors: Pinar
authors: P
authors: Gul
authors: Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University, Erzurum, 25240, Turkey.
authors: Hamit Hakan
authors: HH
authors: Alp
authors: Department of Biochemistry, Faculty of Medicine, Atatürk University, Erzurum, 25240, Turkey.
authors: Ahmet
authors: A
authors: Kiziltunc
keywords: Composite resin; nitric oxide; saliva; uric acid