Effects Of Bone Marrow Aspirate Concentrate On The Peri-implant Osseous Defects: A Micro-CT Study

Objective: The Micro-CT, which is admitted as the gold standard[1]toevaluate the in vitro bone microstructure, can directly analyze thethree-dimensional structure of trabecular and is widely used to research theosseous disease. However, this useful method has not been generallyadopted in the field of oral implantology. On using the mirco-CT, ourpurpose of this research is to evaluate the influence of Bone MarrowAspirate Concentrate (BMAC) which is transplanted to the peri-implantosseous defects on the quantity and quality of the regenerated bone.Methods: Six healthy adult mongrel dogs were selected, which wereextracted of mandibular third and fourth premolars (P3and P4) to createedentulous regions. Three months later, four implants were inserted in thesite of the extracted regions in each dog, and osseous defects at the mesialof the implants were created.Two defects were filled with bone marrowaspirate concentrate (group BMAC), others were filled with autologousalveolar bone (group AB) and Gelatin sponge (control group) respectively.Three dogs were sacrificed at the end of the4th week and12th weekrespectively. Twenty four specimens which include twelve specimens of thefourth week after operation and twelve specimens of the twelfth week afteroperation were scanned and reconstruction by Micro-CT. The bone volumefraction (BV/TV:%), trabecular number (Tb.N:1/mm), trabecular thickness(Tb.Th: mm), trabecular separation (Tb.Sp:mm), trabecular connectivitydensity (Conn.Dn:1/mm3) and structure model index (SMI) from the bonedefects were analyzed by the CTan software.Results: At the end of fourth week, there was a significant difference among three groups in Tb.Sp,(P=0.039， P＜0.05). No significantdifferences in other parameters were found among three groups at the end offourth and twelfth week（P＞0.05）.There was a increase in BV/TV andTb.Th as well as a decrease in the Tb.Sp and SMI in all three groups; theTb.N in group BMAC and group AB decreased and that in group controlincreased; the Conn.Dn in group BMAC and group control increased andthat in group AB decreased, these indexs were not significantly differentamong three groups (P＞0.05)(table1).Conclusions:1. Bone marrow aspirate concentrate with good biocompatibility andosteoinduction is an ideal substitute to repair the peri-implant osseousdefects effectively.2. Bone marrow aspirate concentrate could accelerate the bone regenerationof peri-implant osseous defects, bone quality repaired by bone marrowaspirate concentrate is better than which repaired by autologous alveolarbone at the end of fourth week.3. Micro-CT can analyse peri-implant trabecular microstructural effectively.