SPECT in the long-term evaluation of osteointegration in intraoral and extraoral implantology

Role of single photon emission computerised tomography in evaluating osseointegration of indigenous DRDO implants: An in vivo study

BACKGROUND

A study of first indigenous titanium dental implant developed by DRDO was undertaken at INMAS, Delhi. The aim was to establish the time taken for osseointegration, along with objectives to define the time of implant loading and compare the osseointegration of indigenous dental implants with already established dental implant systems.

METHODS

21 subjects rehabilitated using 39 indigenous dental implants were evaluated by bone SPECT before implantation and at regular intervals towards establishing the aim and objectives.

RESULTS

The rise followed by fall in Osteoblastic activity indicates the postoperative physiologic changes, which peaked at 2 weeks (mean) post-implantation and falls off to pre-implantation levels in 12 weeks (mean) indicating completion of osseointegration, healing and time of loading.

CONCLUSION

It can be summarized that the Osteoblastic activity of indigenous dental implants completes within three months, which can be taken as the time required for complete healing/osseointegration and loading the implants. On comparison with the available data of already established implants the figures appear similar, indicating indigenous implants to be similar in biologic behaviour.

Evaluation of osteoblastic activity around dental implants using bone scintigraphy

OBJECTIVES

The aim of this study was to evaluate the osteoblastic activity around delay-loaded intraosseous dental implants using nuclear medicine imaging techniques.

MATERIAL AND METHODS

Seven totally edentulous patients (two females and five males, between 48 and 57 years of age) were included in the study. Two implants were inserted into mandibular canine regions and removable prostheses were produced after 3 months. Whole-body bone scintigraphies with 20 mCi technetium 99m labelled methylene diphosphonate were taken from the patients before implant insertion, 3 months after implant placement just before the prostheses were made and 1 year after implant placement. Standardized count/pixel (SC/P) rates were calculated for each patient. Preimplantation SC/P values were compared with the 3- and 12-month values. Three-month values were compared with the 12-month values as well.

RESULTS

SC/P rates in the third month were significantly higher (P<0.05) than preoperative values and the SC/P rates of the 12th month were significantly lower (P<0.05) than 3-month values. The SC/P rates of the 12th month were relatively higher than first scintigraphies but the difference was insignificant (P>0.05).

CONCLUSIONS

Within the limitations of this study, in which delayed loading was applied, we showed that osteoblastic activity persisted more in delay loaded implants than immediate and early loading. After 1 year, there was no cellular activity around two implants and this implied that two implants were sufficient for a total prosthesis.