EVALUATION OF MICROBIAL FLORA IN PATIENTS WITH GINGIVAL ENLARGEMENT DURING THE TREATMENT AND SURFACE CHEMISTRY OF FIXED ORTHODONTIC APPLIANCE ARCHWIRE

摘要

Gingival enlargement is a common complication of treatment with a fixed orthodontic appliance, biocompatible stainless-steel archwires AISI 304L (SS). Due to the retention areas, dental plaque accumulation is increased, which results in anaerobic conditions, favourable for periodontopathogenic bacteria. Therefore, it is reasonable to assume that periodontopathogenic bacteria can be found in patients with fixed orthodontic appliances. Organic deposits on the surface of archwires were analyzed. Twenty-one patients with fixed orthodontic appliances and gingival enlargement in the upper dental arch were included in the study. For a determination of the periodontopathogenic bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Tannerella forsythia and Treponema denticola the molecular microbiological method GenoType Test System was used. For the surface analysis of new and in-vivo exposed SS archwires X-ray Photoelectron Spectroscopy was used. The average probing depth at the baseline was 3.76 +/- 0.85 mm. Three types of periodontopathogenic bacteria, namely A. actinomycetemcomitans, T. forsythia and T. denticola, were found to be present. The thickeness of the thin oxide film on new archwires was 8 nm, while organic deposits on the in-vivo exposed archwires was estimated to 60-80 nm. Anaerobic periodontopathogenic bacteria can be found in patients with fixed orthodontic appliances. Therefore, special care is recommended during this kind of treatment.