Estimating the Effects of Dental Caries and Its Restorative Treatment on Periodontal Inflammatory and Oxidative Status: A Short Controlled Longitudinal Study

Abstract

Dental caries and periodontitis are among the most common health conditions that are currently recognized as growing socio-economic problems relating to their increasing prevalence, negative socio-economic impact, and harmful effects on systemic health. So far, the exact effects of caries and standard restorative materials on periodontal inflammatory and oxidative status are not established. The present study aimed to investigate the effect of caries and its restoration using standard temporary and permanent filling materials on a panel of 16 inflammatory and oxidative markers in gingival crevicular fluid (GCF) of periodontally healthy individuals, 7 (D7) and 30 (D30) days post-restoration, while the intact teeth represented the control. One hundred ninety systemically and periodontally healthy patients with occlusal caries underwent standard cavity preparation and restorations with one of six standard temporary or permanent restorative material according to indication and randomization scheme. Interleukin (IL)-2, IFN- γ, IL-12, IL-17A, IL-13, IL-9, IL-10, IL-6, IL-5, IL-4, IL-22, TNF-α, IL1- β, thiobarbituric acid reactive substances, superoxide dismutase, and reduced form of glutathione were measured in GCF samples by flowcytometry and spectrophotometry in aid of commercial diagnostic assays. Caries affected teeth exhibited significantly increased IL-1 β, IL-17, IL-22, and TBARS and decreased IL-9 concentrations compared to healthy controls. Treatment generally resulted in an increased antioxidant capacity with exception of zinc-polycarboxylate cement showing distinctive inflammatory pattern. Comparison of inflammatory and oxidative profiles in temporary and permanent restorations showed material-specific patterning which was particularly expressed in temporary materials plausibly related to greater caries extension. Caries affected teeth exhibited a balanced inflammatory pattern in GCF, with a general tendency of homeostatic re-establishment following treatment. Restorative materials did not provide specific pathological effects, although some material groups did exhibit significantly elevated levels of inflammatory and oxidative markers compared to healthy controls, while the material-specific patterning was observed as well.

Keywords: caries; cytokines; dental restoration; inflammation; oxidative stress; periodontitis; periodontium; restorative material.

Figure 1

Graphical flowchart and study design. Superoxide dismutase (SOD), expressed as U SOD/mg proteins. 3) Reduced form of glutathione (GSH).

Figure 2

Biomarker changes from baseline to 7 and 30 days post treatments by the experimental groups. ZPCEM showed significant changes at the 30D; thus, the levels of IL-17 significantly declined (p = 0.037), while reduced form of glutathione (GSH) and superoxide dismutase (SOD) increased compared to baseline (p < 0.05). In GIC, the GSH significantly increased from baseline to 7D (p = 0.036) and 30D (p = 0.021). In ZPCCEM, the levels of Th1 and Th2 markers as well as SOD significantly increased D7, while D30 in addition to Th1 and Th2 markers the IL-17 significantly increased relative to baseline (p < 0.05). In GIC group, GSH was single marker that significantly increased D7 (p = 0.045) and D30 (p = 0.015) compared to baseline. In AMG, the levels of IL-12 (p-0.30) and IL-22 (p = 0.027) significantly declined D30, while GSH (p = 0.040) and SOD (p = 0.030) levels significantly increased D7 and D30. In COMP, the levels of IL-13 (p = 0.045) and IL-22 (p = 0.021) significantly decreased D7, D30 IL-5 declined when compared to baseline (p = 0.027), while IL-17 and SOD significantly decreased at D7 and D30 (p < 0.05). In COMP+F, the levels of IL-17 declined (p = 0.045), while TNFα, GSH, and SOD significantly increased D7 (p < 0.05), and D30 IL-17, GSH and SOD preserved the trend from D7 (p < 0.05), while IL-5 declined compared to baseline (p = 0.040). ZPCEM, zinc phosphate cement; GIC, glass ionomer cement; ZPCCM, zinc-polycarboxylate cement; AMG, amalgam; COMP-resin, COMP+F-fluoride loaded resin; *p < 0.05.

Figure 3

Biomarker levels between different restorative materials 7 and 30 days post-restoration. ZPCCM exhibited remarkably increased values of Th1 (IFNγ and IL-2; p < 0.05), Th2 (IL-4, IL-5, Il-6 and IL-13 p < 0.05), Th13 (IL-13; p = 0.045), and Th17 (IL-17; p = 0.021) markers. ZPCCM and COMP+F exhibited significantly elevated levels of IL-4 that were significantly higher compared to ZPCEM and COMP (p < 0.05), and for all other permanent fillings, respectively. The highest GSH levels were demonstrated for reduced form of glutathione (GSH) in ZPCEM and COMP+F, for superoxide dismutase (SOD) in COMP and COMP+F, and for thiobarbituric acid reactive substances (TBARS) in GIC that simultaneously demonstrated significantly reduced SOD values compared to all permanent fillings and ZPCEM (p < 0.05). D30 ZPCCM conserved significantly increased Th1(IL-1 and IL-2; p < 0.05), Th2 (Il-4, Il-5, IL-6; p < 0.05), Th13 (IL-13; p = 0.040), and Th17 (IL-17; p = 0.037) markers, while IL-22 was additionally increased in this timepoint (p = 0.021). Regarding inflammatory markers, GIC, ZPCEM, and AMG showed increased values of IL-13, IL-9, and IL-10, respectively (p < 0.05). ZPCEM, GIC, and COMP+F exhibited the highest GSH values (p < 0.05), GIC maintained the trend of the highest TBARS values (p = 0.001), while COMP and COMP+F exhibited the highest SOD values (p < 0.05). ZPCEM, zinc phosphate cement; GIC, glass ionomer cement; ZPCCM, zinc-polycarboxylate cement; AMG, amalgam; COMP-resin, COMP+F-fluoride loaded resin; *p < 0.05.