The relationship between initial implant stability quotient values and bone-to-implant contact ratio in the rabbit tibia

PURPOSE: Implant stability quotient (ISQ) values have been supposed to predict implant stability. However, the relationship between ISQ values and bone-to-implant contact ratio (BIC%) which is one of the predictors of implant stability is still unclear. The aim of the present study was to evaluate initial ISQ values in relation to BIC% using rabbit model. MATERIALS AND METHODS: Four New Zealand white rabbits received a total of 16 implants in their tibia. Immediately after implant placement ISQ values were assessed. The measurements were repeated at the time of sacrifice of the rabbits after 4 weeks. Peri-implant bone regeneration was assessed histomorphometrically by measuring BIC% and bone volume to total volume values (bone volume %). The relationships between ISQ values and the histomorphometric output were assessed, and then, the osseointegration prediction model via the initial ISQ values was processed. RESULTS: Initial ISQ values showed significant correlation with the BIC%. The bone volume % did not show any significant association with the ISQ values. CONCLUSION: In the limitation of this study, resonance frequency analysis is a useful clinical method to predict the BIC% values and examine the implant stability.

Removal Torque and Histometric Evaluations of Implants with Various Area of Hydroxyapatite Coating Placed in the Rabbit Tibia / 대한치주과학회지

BACKGROUND: This study presents a biomechanical and histometric comparison of bone response to implants with various area of hydroxyapatite(HA) coating. METHODS: The implants were placed in the tibia of 10 rabbits weighing 2.5-3.5kg. The control group had a machined surface, the experimental group 1 had 50micrometer thick HA coated in a band form, and the experimental group 2 had 50micrometer thick HA coated on the entire surface. 8 weeks after implantation, the animals were sacrificed. Removal torque was measured and histologic preparation was also performed for histologic and histometric analysis. Bone to implant contact as well as percentage of bone area inside threads were measured. ANOVA post hoc, and t-test were used for statistical analysis with p-value p<0.05. RESULTS: 1. The removal torques were 9.36 +/- 5.64 Ncm, 48.40 +/- 16.66 Ncm, and 82.37 +/- 22.56 Ncm for the control, exp. 1, and exp. 2 group respectively. Statistically significant difference were found among all the groups(p<0.05). 2. Bone to implant contact in the cortical bone were 38.94 +/- 10.9 %, 66.90 +/- 14.1 %, 73.00 +/- 19.4 %, in the marrow bone, 8.30 +/- 5.4 %, 14.59 +/- 5.9 %, 18.54 +/- 11.8 %, and in total, 22.40 +/- 10.1 %, 31.19 +/- 7.5 %, 41.41 +/- 12.2 % for the control, exp.1, and exp. 2 group respectively . In the cortical bone, exp. 1, and exp. 2 group showed statistically significantly higher contact compared to control group. Total contact and in the marrow bone, only exp. 2 group showed statistically significantly higher contact compared to control group(p<0.05). In all the groups significantly higher contact were observed in the cortical bone compared to the marrow bone(p<0.05). 3. Percentage of bone area inside threads in the cortical bone were 55.68 +/- 7.25 %, 55.19 +/- 13.19 %, 57.04 +/- 13.33 %, in the marrow bone, 12.34 +/- 14.61 %, 17.56 +/- 20.04 %, 20.26 +/- 12.83 %, and in total, 30.30 +/- 12.46 %, 31.57 +/- 15.15 %, 34.25 +/- 12.56 % for the control, exp.1, and exp. 2 group respectively. There was no statistical difference among the groups. In all the groups significantly higher bone area were observed in the cortical bone compared to the marrow bone(p<0.05)

Autogenous Living Bone Graft and Dead Bone Graft in the Rabbit Tibia / 대한정형외과학회잡지

A tibial segment in 3cm length with vascular pedicle and periosteum (Living bone graft) and the segment without vascular pedicle and periosteum (Dead bone graft) was obtained from twenty four rabbits, being divided into two group respectively. Then it was replaced with the segmental bone in the initial osteomized defect. The grade of healing and the time factor required to accomplish the repair of resected segmental tibial transplant was determined at one week interval during one to eight weeks, aimed by the,comparative studies of microscopic (gross), radiological as well as histological observation during the healing process. The average time of callus formation in the living bone graft was approximately two weeks, as compared to four weeks of the dead bone graft. Radiographically the average time of bone union in the living bone graft was four weeks, compared with seven weeks for the dead bone graft. The living bone graft was permitted to the healing process of the simple fracture at the graft-recipient bone juncture, in the contrast with the dead bone graft it was united with replacement of the grafted bone by new bone, so called “creeping substitution”.