Yoshiaki Ninomiya

Risk of bacterial contamination of bone harvesting devices used for autogenous bone graft in implant surgery

BackgroundVarious instruments have been developed for collecting bone debris during intraoral autogenous bone graft procedures in implant surgery. The aim of this study was to quantitatively determine the degree of contamination in bone debris collected by different devices.MethodsTwelve patients underwent autogenous bone collection using a bone chisel, bone scraper, trephine drill, and bone filter during bone augmentation surgery as a part of implant therapy, and the total bacterial count in bone debris collected by each was determined.ResultsFollowing anaerobic incubation, bacterial colony formation was found in all of the samples. The mean colony forming units (CFU)/g in samples collected by the trephine drill was found to be significantly lower than that of samples obtained with the other devices, while those values for samples collected by the bone scraper and bone filter was significantly higher as compared to the bone chisel and trephine drill.ConclusionThe bacterial levels may still carry the infection risk. Thus prophylactic antibiotic therapy maybe indicated when using bone particles for intraoral augmentation procedures.

Effects of Apatite Cement Containing Atelocollagen on Attachment to and Proliferation and Differentiation of MC3T3-E1 Osteoblastic Cells

To improve the osteoconductivity of apatite cement (AC) for reconstruction of bone defects after oral maxillofacial surgery, we previously fabricated AC containing atelocollagen (AC(ate)). In the present study, we examined the initial attachment, proliferation and differentiation of mouse osteoblastic cells (MC3T3-E1 cells) on the surface of conventional AC (c-AC), AC(ate) and a plastic cell dish. The number of osteoblastic cells showing initial attachment to AC(ate) was greater than those attached to c-AC and similar to the number attached to the plastic cell wells. We also found that osteoblastic cells were well spread and increased their number on AC(ate) in comparison with c-AC and the wells without specimens, while the amount of procollagen type I carboxy-terminal peptide (PIPC) produced in osteoblastic cells after three days on AC(ate) was greater as compared to the others. There was no significant difference in regard to alkaline phosphatase (ALP) activity and osteocalcin production by osteoblastic cells among the three surface types after three and six days. However, after 12 days, ALP activity and the produced osteocalcin were greater with AC(ate). In conclusion, AC(ate) may be a useful material with high osteoconductivity for reconstruction of bone defects after oral maxillofacial surgery.

Application of interconnected porous hydroxyapatite ceramic block for onlay block bone grafting in implant treatment: A case report (Review)

Autogenous block bone grafting as treatment for alveolar ridge atrophy has various disadvantages, including a limited availability of sufficiently sized and shaped grafts, donor site morbidity and resorption of the grafted bone. As a result, interconnected porous hydroxyapatite ceramic (IP-CHA) materials with high porosity have been developed and used successfully in orthopedic cases. To the best of the authors knowledge, this is the first report of clinical application of an IP-CHA block for onlay grafting for implant treatment in a patient with horizontal alveolar atrophy. The present study performed onlay block grafting using an IP-CHA block to restore bone volume for implant placement in the alveolar ridge area without collecting autogenous bone. Dental X-ray findings revealed that the border of the IP-CHA block became increasingly vague over the 3-year period, whereas CT scanning revealed that the gap between the block and bone had a smooth transition, indicating that IP-CHA improved the process of integration with host bone. In follow-up examinations over a period of 5 years, the implants and superstructures had no problems. An IP-CHA block may be useful as a substitute for onlay block bone grafting in implant treatment.