James Yoon



Document Type


Degree Name



Dept. of Periodontology


Oregon Health & Science University



The aim of this study was to conduct temporal and spatial observations of osteoclastic activity (OA) at periodontal and implant sites following buccal and lingual flap reflection and surgical reduction of the alveolar ridge in a canine periodontal and peri-implant regeneration model to provide baseline information for the design of future studies investigating alveolar OA following injury.

Methods and Materials

Samples for analysis were obtained from a previous study, which evaluated pre-osteoblastic activity.14 Contralateral routine critical-size, supraalveolar, periodontal (PD) and peri-implant (PID) defects including a space-providing titanium mesh device were created in 12 adult mongrel dogs. Two animals were euthanized at 2, 5, 9 and 14 days, and two at 4 and 8 weeks, to provide tissue samples for histochemical analysis of OA by tartrate-resistant acid phosphatase (TRAP) staining of osteoclasts (OC).


For PD, depending on the location, OA peaked between Days 5-14 in resident tissue, with greater numbers of OC at buccal than at lingual sites. OA in the periodontal ligament and resident trabeculae peaked at 5-9 days with some activity still present at 4 and 8 weeks. For PID, OA also seemed to peak by between Day 5-14; with buccal and lingual sites roughly similar, and osteoclasts still present at 8 weeks. OA at the bone-implant interface apparently peaked by day 14 to gradually attenuate. For PD and PID, OA in new osteoid broadly peaked around one month, but was still present at two months.


Broadly, OA in resident tissues following PD/PID creation peaked by 14 days to gradually return to baseline by 8 weeks. This timing was consistent with the established coupling of osteoblast and osteoclast activity, with an early phase of osteoblast activity during the first two weeks inducing a transient peak of OA. The data was suggestive of a second peak of OA induced during the 4-8 week period, and likely associated with late bone remodeling and cortication. There were also indications that autologous blood could alter the timing and reduce the extent of peak OA.




School of Dentistry



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