Complications with dental implantation

Purpose:The primary goal of the study is to observe an intraoperative complication of implant placement due to loss of bone resistance. To highlight the challenges of dealing with surgical complications associated with an appropriate implant treatment plan.Methodology: The study presents the case of a 50-years old patient who complains of pain in the area of the right maxillary second molar. A clinical and radiographic examination was performed. A surgical plan was made involving the placement of two implants with prior extraction of the right maxillary second molar. An evaluation was performed in a period of 6 months after the implantation.Results: The evaluation showed that there was no bone defect, the grafted bone was well healed, and the final restoration was set 2 months after the abutment healed. The patient was followed up clinically and radiographically after 6 months of initial surgery. Periodic evaluation did not reveal any pathological periimplant bone loss.Conclusions: Complications are an expected occurrence and can compromise the entire treatment. Invasion of the maxillary sinus by implant can occur during or after surgery. A competent surgeon is needed to prepare an appropriate pre-treatment evaluation, to prepare an appropriate treatment planand adequately to recognize a complication during surgical procedure and appropriately to approach its solution and minimize the negative outcome.Recommendations: With adequate knowledge of anatomy and procedures as well as considering the possibilities for avoiding complications, by managing and planning a possible treatment a satisfactory result will be achieved in an appropriate patient.Keywords:implants, complications, implantation, implant failure

Palladium(II) complexes of quinolinylaminophosphonates: synthesis, structural characterization, antitumor and antimicrobial activity

Three types of palladium(II) halide complexes of quinolinylaminophosphonates have been synthesized and studied. Diethyl and dibutyl [alpha-anilino-(quinolin-2-ylmethyl)]phosphonates (L1, 12) act as N,N-chelate ligands through the quinoline and aniline nitrogens giving complexes cis-[Pd(L1/12)X-2] (X Cl, Br) (1-4). Their 3-substituted analogues [alpha-anilino-(quinolin-3-ylmethyl)]phosphonates (L3, L4) form dihalidopalladium complexes trans-[Pd(L3/L4)(2)X-2] (5-8), with trans N-bonded ligand molecules only through the quinoline nitrogen. Dialkyl [alpha-(quinolin-3-ylamino)-N-benzyl]phosphonates (L5, L6) give tetrahalidodipalladium complexes [Pd-2(L5/L6)(3)X-4] (9-12), containing one bridging and two terminal ligand molecules. The bridging molecule is bonded to the both palladium atoms, one through the quinoline and the other through the aminoquinoline nitrogen, whereas terminal ligand molecules are coordinated each only to one palladium via the quinoline nitrogen. Each palladium ion is also bonded to two halide ions in a trans square-planar fashion. The new complexes were identified and characterized by elemental analyses and by IR, UV-visible, H-1, C-13 and P-31 nuclear magnetic resonance and ESI-mass spectroscopic studies. The crystal structures of complexes 1-4 and 6 were determined by X-ray structure analysis. The antitumor activity of complexes in vitro was investigated on several human tumor cell lines and the highest activity with cell growth inhibitory effects in the low micromolar range was observed for dipalladium complexes 11 and 12 derived from dibutyl ester L6. The antimicrobial properties in vitro of ligands and their complexes were studied using a wide spectrum of bacterial and fungal strains. No specific activity was noted. Only ligands L3 and L4 and tetrahalidodipalladium complexes 9 and 11 show poor activities against some Gram positive bacteria

Individual energy level distributions for one-dimensional diagonal and off-diagonal disorder

We study the distribution of the $n$-th energy level for two different one-dimensional random potentials. This distribution is shown to be related to the distribution of the distance between two consecutive nodes of the wave function. We first consider the case of a white noise potential and study the distributions of energy level both in the positive and the negative part of the spectrum. It is demonstrated that, in the limit of a large system ($L\to\infty$), the distribution of the $n$-th energy level is given by a scaling law which is shown to be related to the extreme value statistics of a set of independent variables. In the second part we consider the case of a supersymmetric random Hamiltonian (potential $V(x)=\phi(x)^2+\phi'(x)$). We study first the case of $\phi(x)$ being a white noise with zero mean. It is in particular shown that the ground state energy, which behaves on average like $\exp{-L^{1/3}}$ in agreement with previous work, is not a self averaging quantity in the limit $L\to\infty$ as is seen in the case of diagonal disorder. Then we consider the case when $\phi(x)$ has a non zero mean value.Comment: LaTeX, 33 pages, 9 figure

Hochleistungsgeräuschdämpfer für axiale Hauptgrubenlüfter

Die ständig arbeitenden Hauptgrubenlüfter sind starke Geräuschquellen im Untertagebau. Das Geräusch in diesen Ventilatoren ist hauptsächlich bedingt durch aerodynamische Vorgänge und weniger durch die mechanischen Schwingungen der Konstruktion