Development Of Implant/Interconnected Porous Hydroxyapatite Complex As New Concept Graft Material

Background: Dental implant has been successfully used to replace missing teeth. However, in some clinical situations, implant placement may be difficult because of a large bone defect. We designed novel complex biomaterial to simultaneously restore bone and place implant. This complex was incorporated implant into interconnected porous calcium hydroxyapatite (IP-CHA). We then tested this Implant/IP-CHA complex and evaluated its effect on subsequent bone regeneration and implant stability in vivo.Methodology/Principal Findings: A cylinder-type IP-CHA was used in this study. After forming inside of the cylinder, an implant was placed inside to fabricate the Implant/IP-CHA complex. This complex was then placed into the prepared bone socket in the femur of four beagle-Labrador hybrid dogs. As a control, implants were placed directly into the femur without any bone substrate. Bone sockets were allowed to heal for 2, 3 and 6 months and implant stability quotients (ISQ) were measured. Finally, tissue blocks containing the Implant/IP-CHA complexes were harvested. Specimens were processed for histology and stained with toluidine blue and bone implant contact (BIC) was measured. The ISQs of complex groups was 77.8 +/- 2.9 in the 6-month, 72.0 +/- 5.7 in the 3-month and 47.4 +/- 11.0 in the 2-month. There was no significant difference between the 3- or 6-month complex groups and implant control groups. In the 2-month group, connective tissue, including capillary angiogenesis, was predominant around the implants, although newly formed bone could also be observed. While, in the 3 and 6-month groups, newly formed bone could be seen in contact to most of the implant surface. The BICs of complex groups was 2.18 +/- 3.77 in the 2-month, 44.03 +/- 29.58 in the 3- month, and 51.23 +/- 8.25 in the 6-month. Significant difference was detected between the 2 and 6-month.Conclusions/Significance: Within the results of this study, the IP-CHA/implant complex might be able to achieve both bone reconstruction and implant stability. Citation: Doi K, Oue H, Morita K, Kajihara S, Kubo T, et al. (2012) Development of Implant/Interconnected Porous Hydroxyapatite Complex as New Concept Graft Material. PLoS ONE 7(11): e49051. doi:10.1371/journal.pone.0049051