The stability of titanium dental implants is determined by osseointegration
. Bone is a dynamic tissue continuously remodeled through resorption and fo
rmation, processes controlled by local cytokine production. This study inve
stigated osseotropic cytokine expression in gingival mucosa, in the intrafo
ramina and inferior first molar zones, during rehabilitation with implant-r
etained overdentures. Specimens were taken from six patients prior to place
ment of implants in the intraforamina bone; at connection of healing abutme
nts; and 4, 8, and 12 months after prosthetic anchorage. Through semi-quant
itative reverse-transcriptase polymerase chain-reaction, the following cons
titutively expressed cytokines were found at first surgical stage: interleu
kin-1, -6, and -8; small amounts of interleukin-11; stem cell factor; and t
ransforming growth factor-beta 1, -beta 2, and -beta 3. From the connection
of healing abutments to 12 months after prosthetic anchorage, transforming
growth factor-beta 1, -beta 2, and -beta 3 were markedly higher than initi
al values. Expression of interleukin-6 and -8 decreased 8 months after pros
thetic anchorage, while that of interleukin-l increased at 12 months. In cu
ltured gingival fibroblasts, modulation of cytokine secretion was also time
-dependent. Cell culture supernatants influenced osteoclast-like multinucle
ated cell formation in long-term human marrow culture or osteoblast functio
n, depending on the cytokine profile produced. These results are consistent
with functional contributions of cytokines to osseointegration and minimiz
ation of posterior edentulous zone bone resorption.