Sinus Augmentation with Porous Titanium Granules -MicroCT and Histological Analysis

Objectives:

This study aimed at assessing bone ingrowth in porous titanium granules used for maxillary sinus augmentation.

Methods:

19 biopsies from 18 patients participating in a clinical trial on sinus augmentation using porous titanium granules (PTG, Tigran Technologies AB, Sweden) were received in the lab. The biopsies (trephine-cores of 4 mm) were taken six months after placement. After embedding in methacrylate (Technovit 7200 VLC, Heraeus-Kulzer, Germany) the biopsies were scanned in toto in a microcomputed-tomography scanner (SkyScan 1172 microCT, Skyscan N.V., Belgium). After scanning, biopsies were cut along the long axis and central slices were grinded to 70 mm before staining.

Results:

The 3D microCT analysis showed that the biopsies had an average fill of bone and graft material together of 28.7% with a SD of ± 8.3%. The volume of newly formed bone was decreasing with the distance from the residual bone from the sinus floor.

The 2D histomorphometric analysis demonstrated a mean area of new mature, intergranular bone of 16.0% with a SD of ± 9.1%. The PTG graft material alone occupied about 26.2% of the total mean area with a SD of ± 6.0%.

The newly formed bone consisted mainly of woven bone growing in close contact with the surface of the granules and bridging the intergranular space. The remaining area was occupied predominantly by immature bone and soft tissue. There were no signs of inflammation or infections in any of the biopsies.

Conclusions:

At six months post-surgery, the porous titanium granules promote new bone formation at a similar rate and quality as reported for other well-recognized bone graft substitutes. The new bone formed in close contact with the surface of the porous titanium granules suggests that the material is osteoconductive.