Abstract: Objective To evaluate the osseointegration of dental implants with different thread designs in the canine mandible. Methods Four male beagle dogs were selected. Bilateral mandibular premolars and molars (PM2-M2) were extracted and allowed to heal for 12 weeks. The test group was a newly-designed dental implant, and the control group was AstraTech OsseoSpeed^TM TX dental implant. Four implants were implanted (submerged healing) on each side with a split-mouth design. Two animals were sacrificed at 2 and 12 weeks after surgery, respectively (n=8). Intraoral digital X-ray images and non-decalcified hard tissue sections were used for radiological and histological evaluations. Results Radiological images showed similar bone healing in two groups at 2 and 12 weeks after surgery. The histological results showed that at 2 weeks, implants were mainly mechanically inbuilt into the host bone, and a small number of new bones were formed around implants. At 12 weeks, a large number of completely mineralized new bones with the trabecular-liked structure was formed around implants. The bone-implant contact (BIC%) of the test and control group were (46.69±8.47) % and (36.71±13.72) % at 2 weeks, (67.27±7.46) % and (56.63±8.31) % at 12 weeks, respectively, and the difference between groups was not statistically significant. Conclusions Two dental implants with different thread shapes can achieve satisfactory and comparable osseointegration.

Key words: Dental implant, Thread design, Osseointegration, Delayed implant model, Beagle dogs