Periodontal Pathogens in Screw and Cement Retained Prosthetic Appliances

Background: Although implants are widely used in everyday practice there are insufficient data on the type of suprastructure fixation (screw versus cement) of the prosthetic appliance and presence of microbial species. Aim: The aim of the study was to analyse the relationship between the type of prosthetic suprastructure fixation (screwed or cemented) and the presence of A. actinomycetemcommitans, P. gingivalis, T. forsythia, P. intermedia, T. denticola and F. nucleatum. Furthermore, the aim of this study was to evaluate possible correlation between the presence of systemic diseases and the type of the investigated bacteria. Materials and Methods: In fifty one dentate patient, 136 implants were inserted either in the upper or lower jaw in the place where molars were missing. Cemented suprastructure was put in 32 patients and screw retained suprastructure in 19 patients. Samples were taken with sterile paper points before abutment fixation and six months later (three times during ten seconds from the gingival sulcus) and analyzed with real-time polymerase chain reaction. Plaque index, Papillla bleeding index and Community Periodontal Treatment Need Index as well as the presence of systemic diseases was recorded. Shapiro – Wilks test was used when samples were smaller than 30 and Kolmogorov – Smirnov test when they were more than 30. P value under 0.05 was significant. No differences in the presence of A. actinomycetemcommitans, P. gingivalis, T. forsythia, P. intermedia, T. denticola and F. nucleatum with regard to the type of fixation (screwed versus cemented) were seen. There was a significant increase in bacterial count in persons with cardiovascular, rheumatic diseases and in those who took medications and were older. Preoperatively, there was no correlation between periodontal pocket depth with the number of the bacteria. Postoperatively, patients with more periodontal pockets of ≥4 mm harvested higher number of investigated bacteria.