Ac. Aygit et al., Comparison of alloplastic implants for facial bones by scintigraphy and histology: an experimental study, EUR J PLAST, 22(2-3), 1999, pp. 102-106
Reconstruction of bone defects and contour irregularities in the craniofaci
al region is difficult and often requires complex solutions. This study inv
estigated the tissue response, vascularization and bone ingrowth, in hydrox
yapatite, porous polyethylene and silicone elastomer when used as bone graf
t substitutes. 24 albino rabbits (8 rabbits for each implant) were used in
this investigation. Hydroxyapatite 500 particles, silicone rubber and porou
s high-density polyethylene were placed in the cavities formed with a drill
in the rabbit frontal bones. As a part of a prospective study the vascular
ization rates of all implant materials were analyzed 10 days and 2 months a
fter surgery using (99m)Technetium-MDP (Methylene diphosphonate) scintigrap
hy of the skull. The scintigraphic studies were performed 2 hours after int
ravenous injection of 4 mCi (148 MBq) Tc-99m-MDP. The frontal bone was exci
sed on the 10th and 60th days. All tissue specimens were placed first in 10
% formalin and then in 10% nitric acid solution for decalcification. The va
scularization, connective tissue ingrowth, foreign body reaction and bone r
egeneration around the implant were evaluated. Results of this study sugges
ted that hydroxyapatite and porous polyethylene were stabilized in bone whi
le as expected silicone was mobile, also hydroxyapatite implants are vascul
arized better and are more biocompatible than porous polyethylene.