Mansur Ahmad

In the past decade, the utility of cone beam computed tomography (CBCT) images in oral and maxillofacial surgery has seen continuous increase. However, CBCT images are not always able to replace other imaging modalities. Based on the current published knowledge, this paper discusses advantages and limitations of CBCT images in the diagnosis and surgical planning of dentoalveolar procedures, odontogenic cysts, benign and malignant tumours, inflammatory changes, orthognathic surgery, maxillofacial trauma, sinus disorders, and systemic and osseous conditions that manifest in the maxillofacial area. This paper also suggests alternative imaging modalities when CBCT images are not adequate for surgical planning.

The effects of a layer‐by‐layer assembled carbon nanotube composite (CNT‐comp) on osteoblasts in vitro and bone tissue in vivo in rats were studied. The effects of CNT‐comp on osteoblasts were compared against the effects by commercially pure titanium (cpTi) and tissue culture dishes. Cell proliferation on the CNT‐comp and cpTi were similar. However, cell differentiation, measured by alkaline phosphatase activity and matrix mineralization, was better on the CNT‐comp. When implanted in critical‐sized rat calvarial defect, the CNT‐comp permitted bone formation and bone repair without signs of rejection or inflammation. These data indicate that CNT‐comp may be a promising substrate for use as a bone implant or as a scaffold for tissue engineering. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A:, 2010.

Osseointegration of implants in irradiated bone is inadequate. The effect of radiation on cell-implant material interaction has not been adequately studied. The goal of this study was to investigate the effects of ionizing radiationon the proliferation, differentiation, and attachment of osteoblasts to commercially pure titanium (cpTi). Human fetal osteoblasts (hFOB) were irradiated either before or after plating in tissue culture (TC) dishes with or without cpTi disks. Radiation was single dose of 10 cGy, 25 cGy, 50 cGy, 1 Gy, 2 Gy, 4 Gy or 8 Gy. Cell proliferation was determined by counting trypsinized cells on 7 days after irradiation. Attachment of irradiated hFOB was measured indirectly by counting cells 2 and 6 h after plating. Differentiation was evaluated by alkaline phosphatase activity. Compared with nonirradiated sham controls, higher doses of radiation significantly reduced cell attachment and proliferation. Both proliferation and attachment were significantly lower on cpTi compared with TC. Attachment decreased based on the length of postirradiation period. Although differentiation was significantly enhanced by a dose of 8 Gy, proliferation was lowest. These initial studies show that effects of therapeutic doses of radiation on osteoblasts varied depending on the surface, time-elapsed, and amount of radiation. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008