The acute effect of psychosocial stress on the level of oxidative stress in children

The effect of chronic stress on oxidative stress (OS) is commonly discussed while the effect of acute stress situation is not fully examined yet. The present study was aimed to analyse whether acute psychosocial strain causes changes in OS and antioxidant status. Unstimulated saliva was collected from 46 healthy prepubertal children during the control and stress day. On the stress day, collection was performed before and after a stress situation induced by the Trier social stress test. Saliva collection during the control day imitated the stress day without the stress strain. Samples were used for analysis of lipid peroxidation, thiobarbituric acid reactive substances (TBARS), advanced glycation end products (AGEs) and markers of antioxidant status, total antioxidant capacity (TAC) and ferric reducing antioxidant power (FRAP). On the stress day, increased level of FRAP was observed in the second saliva collection in comparison with the first collection. Within the same day, no significant changes in the levels of TBARS, AGEs and TAC were observed in samples taken before and after stress strain. Significantly higher levels of TBARS were observed on stress day in comparison to control day. In summary, acute psychosocial stress caused increase of FRAP during the stress day. TBARS did not increase during the stress day in the second sample but it was higher compared to the control day. None of the interactions with gender were statistically significant. It appears the short-term exposure to stress could potentially stimulate antioxidant activity.

Glycation and oxidative stress in the failure of dental implants: a case series

Background

The aim of this case series/control study is to investigate the presence of the Advanced Glycation End products (AGEs) and oxidative stress in periimplantitis.

The study group was composed of five dental implants, failed within 6 months after implantation, taken from 5 subjects (3 M/2 F) aged between 43–57 years and stored in isotonic liquid before freezing at -80°C, according to literature. All the implants had been placed using traditional submerged technique. The whole saliva was also collected using Salimetrics device and stored at -80°C, to assess molecular analysis. Two age-matched control groups were examined: they consisted of 5 subjects encountering dental extraction for chronic periodontal disease (2 M/3 F) and 5 healthy subjects (3 M/2 F) who needed extraction for dental trauma. Their whole saliva was collected with the same method. The implants and the tooth of control groups were processed to assess Western Blotting for identification of AGEs. The case/control whole saliva was used to perform ThioBarbituric Acid Reactive Substances (TBARS) for oxidative stress evaluation.

Findings

The Western Blotting analysis on periimplantitis and periodontal disease tissues showed marked increase of AGEs when compared to healthy control tissues. Also TBARS assay of whole saliva confirmed the expectations, showing higher oxidative stress levels in periimplantitis and periodontitis groups than in healthy group.

Conclusions

With the limitation of the sample size, these results showed that oxidative stress could be involved in the aetiology of periimplantitis. This hypothesis could lead to new therapeutic strategies in periimplantitis, using antioxidant approach in addition to conventional treatments.