Evaluation of bone ingrowth into porous titanium implant: histomorphometric analysis in rabbits - PDF


A porous material for bone ingrowth with adequate pore structure and appropriate mechanical properties has long been sought as the ideal bone-implant interface. This study aimed to assess in vivo the influence of three types of porous titanium implant on the new bone ingrowth. The implants were produced by means of a powder metallurgy technique with different porosities and pore sizes: Group 1 = 30 % and 180 µm; Group 2 = 30% and 300 µm; and Group 3 = 40% and 180 µm;. Six rabbits received one implant of each type in the right and left tibiae and were sacrificed 8 weeks after surgery for histological and histomorphometric analyses. Histological analysis confirmed new bone in contact with the implant, formed in direction of pores. Histomorphometric evaluation demonstrated that the new bone formation was statistically significantly lower in the group G1 than in group G3, (P = 0.023). Based on these results, increased porosity and pore size were concluded to have a positive effect on the amount of bone ingrowth.


Titanium (Ti) and its alloys are the most frequently used materials for endosseous implants in dentistry and orthopedics due to their high degree of biocompatibility and good mechanical properties.1 Successful integration of an implant is generally accepted to rely on its surface characteristics such as chemical composition, morphology, and energy.2 Surface morphology is an important factor determining the long-term implant stability, especially when bone quality is poor.3 Porous metals have been exploited for several decades to increase friction force between the implant and bone and promote the initial and long-term stability through bone ingrowth.3,4,5,6

The advantage of porous materials is their ability to provide biological anchorage for the surrounding bone tissue via the ingrowth of mineralized tissue into the pore spaces.7 The architecture of a porous implant has been shown to substantially affect the bone ingrowth into pore space5,8,9. Optimal pore size for bone ingrowth ranges from 100 µm to 600 µm, and the pores must be interconnected to maintain the vascular system required for continuing bone development.8, 9