MICROBIOLOGICAL AND HOST FACTORS ARE INVOLVED IN PROMOTING THE PERIODONTAL FAILURE OF METALOCERAMIC CROWNS.

Abstract This study was aimed at looking into the
microbiological/inflammatory parameters predicting the
periodontal success/failure of fixed prostheses. Microbiological
and inflammatory patterns were studied at 102 sites
having metaloceramic crowns in place from 3 to 6 years
and divided in healthy sites (HS), gingivitis affected (MG),
and periodontitis affected (PB). Total bacterial flora and
selected indicator species in subgingival plaque were
quantified by quantitative real-time PCR. The concentrations
of IL-1β, IL-6, and TNF-α were determined in
gingival crevicular fluid (GCF) by enzyme-linked immunosorbent
assays. The experimental sites showed no
significant difference with respect to the age and gender
of the patients and to the position of the crown margins.
Poor marginal adaptation was significantly higher in MG
and PB. The total amounts of bacteria per probing depth
showed no significant differences among the three groups
and their controls, while both MG and PB sites showed
altered patterns in the distribution of specific bacteria. Both
MG and PB sites showed significantly higher levels of
inflammatory cytokines in GCF. The control teeth of PB
subjects showed significantly higher levels of IL-1β as
compared to other control sites. Data confirm that the
application of metaloceramic crowns is a factor of risk for
the development of gingival/periodontal inflammation. This
risk is possibly associated with microbiological and host
factors that predispose to the onset of periodontal alterations
at sites reconstructed with metaloceramic crowns.
These factors, once their role is confirmed by longitudinal
studies, could be used to set up rapid tests to early predict
the onset of periodontal disease at reconstructed sites.