Clinical, microbiological and immunological findings on peri-implantitis patients with bar-retained lower removable partial dentures, in comparison to a healthy control group (12-month-follow-up).

Abstract

C
ause, treatment strategies and prognosis of peri-implantitis is not well understood. The aim of this study was to follow-up clinical, microbiological and immunological findings in individuals wearing bar-retained lower partial dentures with and without peri-implantitis, pre and post treatment. From the Tuebingen Implant Registry recall program 16 peri-implantitis patients were compared to 16 healthy individuals in a prospective, unblinded study. Peri-implantitis was treated with a single anti-inflammatory therapy according to the CIST protocol while the controls received professional implant cleaning. The following findings were recorded at four time points before treatment (T1) and 30, 90, 360 days post treatment (T2-T4): sulcular fluid flow rate, probing depth, plaque and bleeding index, implant stability (Periotest); sulcular concentrations of interleukin-1 beta, plasminogen activator inhibitor 2, prostaglandin E2, and the sum score of five periodonto-pathogenic bacteria species by PCR (Hain MicroIdent test). Statistically significant differences between healthy and diseased implants were found for probing depth, bleeding on probing, bacterial load, and implant stability. For the first three, a significant decrease in severity was observed after treatment, but reached initial pre-treatment values within one year. No changes could be observed in the individuals without peri-implantitis. The results of the present study confirm marked differences in peri-implant findings between healthy and diseased sites. They demonstrate that a single anti-inflammatory intervention can initially – but not sustained- reduce probing depth, bleeding on probing, and the total bacterial load as evident from PCR diagnostics. Further immunological diagnostic measures do not seem to provide more information in the patients investigated.