**5. Conclusions**

Chronic kidney disease is associated with salivary gland dysfunction and increased oxidative and nitrosative damage. Oxidation of salivary proteins and lipids increases with the progression of the disease and the degree of salivary gland damage. The assessment of salivary gland function should be an integral part of a dental examination in patients with CKD. Antioxidant supplementation may be considered in CKD children; nevertheless, further research is necessary, especially in a larger population of patients.

*J. Clin. Med.* **2020**, *9*, 1285

**Author Contributions:** Conceptualization, M.M. and A.Z.; Data curation, M.M.; Formal analysis, M.M.; Funding acquisition, M.M. and A.Z.; Investigation, M.M., K.T.-J., and A.Z.; Methodology, M.M. and A.Z.; Project administration, M.M. and A.Z.; Resources, M.M., J.S., K.T.-J., A.W., and A.Z.; Software, M.M.; Supervision, A.W. and A.Z.; Validation, M.M.; Visualization, M.M.; Writing—original draft, M.M.; Writing—review and editing M.M., K.T.-J., and A.Z. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was supported by grants from the Medical University of Bialystok, Poland (grant numbers: SUB/1/DN/20/002/1209; SUB/1/DN/20/002/3330).

**Acknowledgments:** The authors would like to thank Anna Skutnik and Izabela Zieniewska for their help in collecting material for research.

**Conflicts of Interest:** The authors declare no conflict of interest.
