Histomorphometric analysis of bone to implant contact (BIC) and bone area was performed at 4 h, 1, 2, 4 and 8 weeks.\n\nWound healing initiated with a coagulum that was substituted by a provisional matrix at 1 week. Bone formation started concomitant to a marked bone resorption. R788 cell line At

2 weeks, woven bone formation was evident and gradually remodelled into lamellar bone at 4 and 8 weeks. BIC increased similarly throughout the study in both groups with a tendency to higher percentages for the test devices at 2 and 4 weeks. The influence of the DCD nano-particles was more evident at the fourth premolar site.\n\nOsseointegration occurred similarly at both implant groups, although the socket dimension appeared to influence bone healing. It is suggested that the enhanced nano-topography has a limited effect in the immediate implant surgical protocol.”
“Purpose: Improving dose calculation accuracy is crucial in intensity-modulated radiation therapy (IMRT). We have developed a method for generating a phase-space-based dose kernel for IMRT planning of lung cancer patients.\n\nMethods: GS-9973 concentration Particle transport in the linear accelerator treatment head of a 21EX, 6 MV photon beam (Varian Medical Systems, Palo Alto, CA) was simulated using the EGSnrc/BEAMnrc code system. The phase space information was recorded under the secondary jaws. Each particle in the phase space file was associated with a beamlet whose index was

calculated and saved in the particle’s Screening Library cell line LATCH variable. The DOSXYZnrc code was modified to accumulate the energy deposited by each particle based on its beamlet index. Furthermore, the central axis of each beamlet was calculated from the orientation of all the particles in this beamlet.

A cylinder was then defined around the central axis so that only the energy deposited within the cylinder was counted. A look-up table was established for each cylinder during the tallying process. The efficiency and accuracy of the cylindrical beamlet energy deposition approach was evaluated using a treatment plan developed on a simulated lung phantom.\n\nResults: Profile and percentage depth doses computed in a water phantom for an open, square field size were within 1.5% of measurements. Dose optimized with the cylindrical dose kernel was found to be within 0.6% of that computed with the nontruncated 3D kernel. The cylindrical truncation reduced optimization time by approximately 80%.\n\nConclusions: A method for generating a phase-space-based dose kernel, using a truncated cylinder for scoring dose, in beamlet-based optimization of lung treatment planning was developed and found to be in good agreement with the standard, nontruncated scoring approach. Compared to previous techniques, our method significantly reduces computational time and memory requirements, which may be useful for Monte-Carlo-based 4D IMRT or IMAT treatment planning. (C) 2012 American Association of Physicists in Medicine. [http://dx.doi.org.