Objective To provide basis for cl inical appl ication of ANKYLOS dental implants by following up alveolar bone status of 318 pieces of restored ANKYLOS dental implants. Methods Between February 2008 and August 2009, 170 patients with dentition defect underwent placement of ANKYLOS dental implants (318 pieces). There were 74 males (133 pieces) and 96 females (185 pieces) with an average age of 43.8 years (range, 23-68 years). After operation, the periapicalX-ray films were taken to observe osseointegration around the neck of implant, alveolar bone resorption, and survival ofimplants. Results All patients were followed up at 6, 12, and 24 months after operation. There were 9 failure implants witha total dental implants survival rate of 97.17% (309/318): 3 at 6 months, 4 at 6-12 months, and 2 at 12-24 months, showing no significant difference in dental implants survival rate among 3 time points (χ2=0.470 3, P=0.492 8). New bone formed around the neck of implant in 4 cases at 6 months and in 31 cases at 12 months; at 6, 12, and 24 months, the bone increase was (0.392 7 ± 0.217 4), (0.633 5 ± 0.202 1), and (0.709 0 ± 0.199 1) mm, respectively, showing significant differences among 3 time points (P lt; 0.05). At 6, 12, and 24 months after operation, the bone loss of other patients was (0.392 7 ± 0.217 4), (0.716 7 ± 0.220 3), and (0.723 2 ± 0.215 4) mm, respectively, showing significant differences among 3 time points (P lt; 0.05). Conclusion After restoration with ANKYLOS dental implant, alveolar bone status is good and the implant success rate is high during short-term follow-up. But further observation and study are required for long-term effectivness.
Objective To evaluate the potential of bioresorbable collagen membrane in a combination with bone marrow stromal cells (BMSCs) or platelet rich plasma (PRP) in repairing alveolar bone defects. Methods The first and second premolars were extracted from the bilateral maxillary and mandibular bone and fouralveolar intrabone defects (8 mm in height, 5 mm in width,15 mm in length) werecreated in 3 male mongrel dogs. The experiment included 4 groups: group A (nothing was used as control group), group B (only Bio-Gide® group C (Bio-Gide® BMSCs) and group D (Bio-Gide®／PRP). The macroscopic, radiographic and histological observations were performed at 4, 8 and 12 weeks after surgery. Results The cells were circle or short spindleshape after 1 day of coculture; and the cellswere polygon and long spindleshape with process after 3 days. The macroscopic observation: after 4 weeks in the defect region, obvious excavation and organization of hematoma were seen in group A; and new bone formation and little organization of hematoma were seen in groups B, C, D. After 8 weeks, excavation was not obvious, fibrous tissue was seen at the top of defect, organized hematoma wasgradually replace by new bone in group A; the edge of membrane broke and adhered to deep tissue and needle could pierce the surface ofdefect in groups B, C, D. After12 weeks,excavation disappeared in 4 groups and fibrous tissue at top of alveolar ridge in group A was thicker than that in groups B, C, D. The radiographic observation: defect was full of new bone. In groups A, B, C and D, the grey values were 68, 50, 56 and 49 after 4 weeks; 46, 30, 24 and 30 after 8 weeks; and 24, 17, 15 and 20 after 12 weeks respectively. The histological observation:after 4 weeks, a lot of fibrous connective tissues granulation tissues were seen no obvious new bone formed in group A; and the collagen structure of membrane remained and new bone formed in medial surface in groups B, C, D. After 8 weeks, new bone trabecula displayed clump and web in group A; the collagen structureof membrane were not of integrity, and many bone islands and few fibrous connective tissue formed in groups B, C, D. After 12 weeks, defect was filled with newbone in 4 groups. Conclusion Guided bone regeneration (GBR) treatment with collagen membranes may significantly enhance bone regeneration within 8 weeks. Theinfluence of GBR in combination with BMSCs or PRP in accelerating the repair of alveolar bone defects shoud be further investigated.
Alveolar bone reconstruction simulation is an effective means for quantifying orthodontics, but currently, it is not possible to directly obtain human alveolar bone material models for simulation. This study introduces a prediction method for the equivalent shear modulus of three-dimensional random porous materials, integrating the first-order Ogden hyperelastic model to construct a computed tomography (CT) based porous hyperelastic Ogden model (CT-PHO) for human alveolar bone. Model parameters are derived by combining results from micro-CT, nanoindentation experiments, and uniaxial compression tests. Compared to previous predictive models, the CT-PHO model shows a lower root mean square error (RMSE) under all bone density conditions. Simulation results using the CT-PHO model parameters in uniaxial compression experiments demonstrate more accurate prediction of the mechanical behavior of alveolar bone under compression. Further prediction and validation with different individual human alveolar bone samples yield accurate results, confirming the generality of the CT-PHO model. The study suggests that the CT-PHO model proposed in this paper can estimate the material properties of human alveolar bone and may eventually be used for bone reconstruction simulations to guide clinical treatment.