Calcitonin (CT) is reported to be an effective medication for the treatment
of inflammatory root resorption and to be capable of stimulating osteoblas
t proliferation in cell culture studies. In this study the effect of CT on
the healing of osseous defects was evaluated in the mandibles of guinea pig
s. After raising tissue flaps two experimental cavities were created on bot
h sides of the corpus mandible of 33 guinea pigs. CT was applied into cavit
ies either in hydroxypropyl methycellulose (HPMC) gel or gelatin as carrier
. HPMC and gelatin alone and an empty cavity were also examined as control
groups. Histopathological examinations under light microscopy were performe
d on weeks 1, 3, and 6. At week 1 in CT+ and CT+HPMC groups, prominent oste
oblastic activity was observed when compared with control groups. At week 3
the presence of woven bone in the experimental cavity areas reflected the
increased osteoblastic activity in all groups. At the end of week 6 woven b
one was gradually replaced by osteogenic tissue undergoing remodelization w
ith Haversian systems in all groups. It is suggested that the osseous heali
ng of the experimental cavity was enhanced by CT application in early stage
s (i.e. at week 1). However there was no significant difference of osteogen
ic activity between the control and CT-treated groups at the end of weeks 3
and 6.