Introduction. Hemodialysis patients require high standards in the field of dental diseases prevention and also in pharmacological and dialysis methods of combating biochemical disorders. It is necessary to question the methods of monitoring oral hygiene quality among hemodialysis patients.

Aim. The aim of this study was to determine the relationship between Approximal Plaque Index (API) and the quality of life and biochemical parameters of the calcium, phosphate and iron metabolism.

Material and methods. The study was conducted on a group of 124 individuals – 65 women (52%) and 59 men (48%) aged 24-90, volunteered to undergo hemodialysis in chronic renal failure, who consented to participate in this study. All participants of the study were treated for at least 6 months, through repeated hemodialyses in dialysis centers in Lublin. The dental examination was performed and Approximal Plaque Index (API) was determined. The Polish version of the quality of life questionnaire SF-36 was used. The values of urea, serum creatinine concentration, serum level of calcium, serum phosphorus, parathormone, transferrin, ferritin, and iron were also under control. The Kruskal-Wallis H test and Spearman Rank Correlation was used.

Results. Patients with optimal API reported higher levels of iron and lowest concentration of transferrin and serum phosphorus before HD. Patients who were characterized by high levels of phosphate and parathyroid hormone evaluated their functioning in the emotional sphere as worse compared to others. Higher concentrations of iron and transferrin favor a better sense of the quality of life.

Conclusions. Lower concentrations of phosphate before hemodialysis and higher iron levels contribute to maintaining optimal interdental hygiene in patients treated with renal replacement therapy. Normalization of biochemical parameters of calcium-phosphate and iron metabolism promotes a sense of better quality of life among patients on chronic hemodialysis. The level of interdental hygiene does not distinguish between general indicators of the sense of quality of life.