Immediate implant loading following computer-guided surgery

AbstractPurposeThe aim of this study was to develop and apply a new method for easy intraoperative adjustment of a provisional fixed full-arch restoration, in order to allow immediate implant loading following computer-guided surgery, regardless of any implant positioning errors compared to the virtual planning.MethodsIn accordance with the NobelGuide™ protocol, a provisional restoration for immediate loading of six maxillary implants was prepared prior to surgery. Because small shifts between the planned and the actual implant positions were to be expected, the provisional restoration was not fabricated directly on temporary cylinders as a conventional one-piece superstructure, but was divided into two portions: six custom made abutments and a long span fixed restoration which were left unconnected. After implantation, the custom abutments were attached to the six implants to be immediately loaded, and the superstructure was cemented simultaneously to all abutments using dual cure resin cement. After the excess cement was cleaned and polished, the superstructure was then reseated. Passive fit was achieved between implants and the superstructure.ConclusionThe superstructure described in this article can be easily seated and adjusted to accommodate any possible shifts in implant positioning occurring during computer-guided surgery. Through this method uneventful immediate implant loading can be achieved in a reasonable operative time

The 2G allele of promoter region of Matrix metalloproteinase-1 as an essential pre-condition for the early onset of oral squamous cell carcinoma

<p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinase (<it>MMP</it>) is known to be involved in the initial and progressive stages of cancer development, and in the aggressive phenotypes of cancer. This study examines the association of single nucleotide polymorphisms in promoter regions of <it>MMP-1 </it>and <it>MMP-3 </it>with susceptibility to oral squamous cell carcinoma (OSCC).</p> <p>Methods</p> <p>We compared 170 Japanese OSCC cases and 164 healthy controls for genotypes of <it>MMP-1 </it>and <it>MMP-3</it>.</p> <p>Results</p> <p>The frequency of the <it>MMP-1 </it>2G allele was higher and that of the 1G homozygote was lower in the OSCC cases (<it>p </it>= 0.034). A multivariate logistic regression analysis revealed that subjects who were 45 years old or older had a significantly increased (2.47-fold) risk of OSCC (95%CI 1.47–4.14, <it>p </it>= 0.0006), and those carrying the <it>MMP-1 </it>2G allele had a 2.30-fold risk (95%CI 1.15–4.58, <it>p </it>= 0.018), indicating independent involvement of these factors in OSCC. One of the key discoveries of this research is the apparent reduction of the <it>MMP-1 </it>1G/1G and 1G/2G genotype distributions among the early onset OSCC cases under the ages of 45 years. It should be noted that the tongue was the primary site in 86.2% of these early onset cases. This could suggest the specific carcinogenic mechanisms, i.e. specific carcinogenic stimulations and/or genetic factors in the tongue.</p> <p>Conclusion</p> <p>Since the 2G allele is a majority of the <it>MMP-1 </it>genotype in the general population, it seems to act as a genetic pre-condition in OSCC development. However this report suggests a crucial impact of the <it>MMP-1 </it>2G allele in the early onset OSCC.</p

LIF SPECTROSCOPY OF A CARBON CHAIN RADICAL PRODUCED BY A HC3NHC_{3}N DISCHARGE

Author Institution: Department of Pure and Applied Sciences, College of Arts and Sciences; Department of Chemistry, School of ScienceNew electronic transitions of a carbon chain radical containing a nitrogen atom have been observed by LIF spectroscopy. The radical was produced in a supersonic jet by a pulsed discharge of $HC_{3}N$ diluted to 0.3\% with 3atm Ar. We confirmed that the radical contains a nitrogen atom from the fact that the spectrum was not observed when $C_{2}H_{2}$ was used as a precursor. About ten vibronic bands with a 50nsec radiative lifetime have been observed in a region from 27000 to $27400 cm^{-1}$. The observed bands could be classified as $^{2}\Pi_{3/2}-^{2}\Pi_{3/2}$ and $^{2}\Sigma - ^{2}\Sigma$ vibronic bands. The lower state rotational constants of the vibronic bands have been determined to be 0.07537(1) and $0.07932(5) cm^{-1}$ for the $\Pi$ and $\Sigma$ states, respectively. The upper states of $^{2}\Sigma - ^{2}\Sigma$ bands have very large spin-rotation constants, which should be denoted as $\Sigma^{(\pm)}$ subjected to a small Renner-Teller interaction. The new molecule has been tentatively assigned to be the $C_{4}N$ radical. We performed an UMP2 level ab initio calculation with $6-311G^{\ast \ast}$ basis sets for the $C_{4}N$ radical. The estimated rotational constant in the ground state was $0.077 cm^{-1}$. This value agrees well with the observed rotational constants

Integrated Simulation of the Atomization Process of a Liquid Jet Through a Cylindrical Nozzle

The 3-D structure of liquid atomization behavior through a cylindrical nozzle is numerically investigated and visualized by a new type of integrated simulation technique. CFD (Computational Fluid Dynamics) analysis focused on the consecutive breakup of a liquid column, formation of liquid film, and generation of droplets of a cylindrical flow in the outlet section of the nozzle. Utilizing the governing equations for high-speed atomizing nozzle flow based on the LES-VOF model in conjunction with the CSF model, an integrated parallel computation is performed to clarify the detailed atomization process of a cylindrical nozzle flow and to acquire data, which is difficult to confirm by experiment, such as atomization length, liquid core shape, distribution droplet sizes, spray angle and droplet velocity profiles. According to the present analysis, the atomization rate and the droplets-gas two-phase flow characteristics are found to be controlled by the turbulence perturbation upstream of the injector nozzle, hydrodynamic instabilities at the gas-liquid interface, and shear stresses between the liquid core and periphery of the jet

The 2G allele of promoter region of Matrix metalloproteinase-1 as an essential pre-condition for the early onset of oral squamous cell carcinoma-0

<p><b>Copyright information:</b></p><p>Taken from "The 2G allele of promoter region of Matrix metalloproteinase-1 as an essential pre-condition for the early onset of oral squamous cell carcinoma"</p><p>http://www.biomedcentral.com/1471-2407/7/187</p><p>BMC Cancer 2007;7():187-187.</p><p>Published online 5 Oct 2007</p><p>PMCID:PMC2089080.</p><p></p>he ages of 45 and 35 years, respectively