Ispitivanje inflamatornog efekta hemijsko-mehaničke metode retrakcije gingive pri izradi fiksnih protetičkih nadoknada

Abstract

The research started from the assumption that the chemical - mechanical retraction procedure, widely used for making of fixed prosthetic restorations, can lead to damage to the periodontal tissue, primarily to the inflammation of the gingiva. The chemical - mechanical method involves the use a retraction cord soaked in fluid - usually an astringent. The combination of mechanical pressure and chemical action on the gum tissue results in optimal expansion of the gingival sulcus and better control of the secretion of fluid in it, which enables accurate imprinting. The aim of the study was to investigate clinical parameters (gingival index and bleeding index) and salivary concentrations of proinflammatory cytokines (Tumor necrosis factor α, Monocyte Chemoattractant Protein 1, Interleukin 6 and Immunoglobulin A), as well as cytomorphometric analysis of gingival epithelial cells (nucleus surface, circumference of the nucleus, circularity, Feret's diameter, optical density, roundness, and solidity) before and after the chemical-mechanical retraction procedure. The retraction agents used were solutions of aluminum chloride and ferisulfate, and the subjects were divided into two groups depending on whether the procedure was performed on brushed or non-brushed teeth. The results of the study showed that the chemical - mechanical retraction method leads to a statistically significant increase in the values of the gingival index, the bleeding index and salivary concentration of proinflammatory cytokines, which indicates its inflammatory potential. The test values decreased over time, which is evidence of the reversibility of the inflammatory changes that have occurred. The obtained values depended on the retraction agent used, with a stronger inflammatory effect of the ferrisulfate solution. The group of the subjects with prepared teeth had higher values of the examined parameters. The chemical - mechanical retraction procedure caused changes in all cytomorphometric parameters of gingival epithelial cells. The surface area and circumference of the gingival epithelial cell nuclei were larger after retraction, which could be considered as a sign of gingival inflammation. A combination of clinical study and laboratory testing of the potential inflammatory effect of gingival retraction agents has yielded relevant findings applicable in dental practice in order to optimize therapeutic effects with minimal risk of iatrogenic damage.