Suture materials affect pen-implant bone healing and implant osseointegration

The aim of this study was to evaluate the effects of the remnants of two suture materials on osseointegration of titanium implants in a rabbit tibial model. Calibrated defects were prepared in the tibia of five Chinchilla rabbits. Filaments of nonresorb able (NR) nylon or resorbable (R) chitosan were placed at the bone to implant interface, whereas control sites had no suture material. After a healing period of 4 weeks, a pull-out test procedure was performed followed by enzymatic analyses of the wound fluid and relative quantification of mRNA levels for bone-related and cytokine markers from the pen-implant bone. A trend toward a reduced pull-out force was observed in the NR group (NR: 23.0 +/- 12.8 N; R: 33.9 +/- 11.3 N; control: 33.6 +/- 24.0 N). Similarly, the bone resorption marker vacuolar type 11+-ATPase was increased in the NR group compared with that in the control group (P = 0.041). The R group showed trends for lower alkaline phosphatase activity and osteocalcin expression and higher total protein content and RNA compared with the control group. In this submerged healing model, pen-implant bone healing was marginally affected by the two suture materials tested. However, there was a tendency toward better osseointegration and lower expression of bone resorption markers in the R group compared with the control group.