[Elimination of defects in the Schneiderian membrane during sinus lift operations]. / Ustranenie defektov membrany Shneidera vo vremya provedeniya operatsii sinus-liftinga.

PURPOSE: Evaluation of the effectiveness of a new method of plasty of an extensive defect in the mucous membrane of the Schneiderian membrane, which occurs during the sinus lift operation, using an artificial collagen membrane and a developed method for fixing it. MATERIAL AND METHODS: A total of 188 patients took part in the study, all of these patients underwent an open sinus lift operation with simultaneous or delayed implantation. Operations were performed under balanced anesthesia. Six months after the operation, according to computed tomography, the height of the formed bone regenerate was estimated. In the area of each missing tooth, the initial bone height and the resulting bone grafting were assessed. Then we compared the average values before and after the operation, the average height difference before and after the operation. RESULTS: In 19 patients during the sinus lift there was an accidental extensive rupture of the mucous membrane of the maxillary sinus. Elimination of the mucosal defect was carried out according to our patented method. All 188 patients were diagnosed with partial loss of teeth with bone tissue deficiency in the distal maxillary sinus. The height of the alveolar process in the projection of missing teeth ranged from 0.5 mm to 5 mm. Delayed dental implantation was performed when the height of the alveolar bone was less than 3 mm, direct when the presence of 3-5 mm. After 6 months, dental implants were installed in the reconstruction zone, after another 6 months - rational prosthetics. CONCLUSIONS: The proposed method of plastic surgery has the following advantages. Firstly, it allows to eliminate the defect of the mucous membrane together with an increase in the height of the alveolar ridge. Secondly, after this method, the integrity of the mucous membrane will be restored. Thirdly, with an alveolar bone height of 3 mm or more, dental implants should also be installed.

[The relationship between penile hemodynamic parameters in cavernous rteries and penile rigidity].

INTRODUCTION: Blood flow parameters in cavernous arteries during full-erection phase on Doppler ultrasonography are associated with intracavernosal pressure and, consequently, with penile rigidity. AIM: To examine the relationship between blood flow parameters in cavernous arteries and the penile rigidity. MATERIALS AND METHODS: A total of 54 healthy men and patients with erectile dysfunction of various degrees of severity, with mean age of 43,0 +/- 2,2 years ranging from 18 to 74 years, were included in the study. Erectile function was examined and 81 Doppler ultrasonography were performed after intracavernosal injection of alprostadil (10 mcg). In full-erection phase, peak systolic velocity (PSV) and systolic acceleration (SA) were measured, as well as resistive index (RI). Mean values were calculated for both cavernous arteries. Penile rigidity was assessed in three ways: clinical evaluation according to I. Goldstein, measurement of surface rigidity and evaluation of longitudinal rigidity. RESULTS: During Doppler ultrasonography a strong correlation of penile rigidity with RI (0,71-0,85) and SA (0,63-0,69) was found. Indirect assessment of penile rigidity using PSV values was less precise. With RI values close to 1,0, SA is a more reliable method for indirect rigidity assessment. CONCLUSION: Penile blood flow parameters, RI and SA, allow to evaluate a degree of rigidity and to eliminate subjectivity of the specialist performing the examination, as well as to obtain a range of penile rigidity values.

Highly efficient broadband polarization retarders and tunable polarization filters made of composite stacks of ordinary wave plates.

By using the formal analogy between the evolution of the state vector in quantum mechanics and the Jones vector in polarization optics, we construct and demonstrate experimentally efficient broadband half-wave polarization retarders and tunable narrowband polarization filters. Both the broadband retarders and the filters are constructed by the same set of stacked standard multiorder optical wave plates (WPs) rotated at different angles with respect to their fast polarization axes: for a certain set of angles this device behaves as a broadband polarization retarder, while for another set of angles it turns into a narrowband polarization filter. We demonstrate that the transmission profile of our filter can be centered around any desired wavelength in a certain vicinity of the design wavelength of the WPs solely by selecting appropriate rotation angles.

Histologic study of biocompatibility of the "Cristaloy 7-N" alloy.

The most commonly used alloy in dentistry practice in metal-ceramic prosthetic constructions is cobalt-chromium-molybdenum alloy. In Bulgaria the company "Sandental" created a nickel-based alloy for metal-ceramic prostheses. The aim of the study was to asses the medicobiological properties of the nickel-chromium-molybdenum alloy "Cristaloy 7-N". The study was performed on eight guinea pigs and four white rats. On both sides of the vertebral column, parallel to it, experimental plates of "Cristaloy 7-N" were implanted on one of the sides and on the contralateral side - golden alloy - .916 gold. After a different period of time - 10, 30, and 90 days, the experimental animals were eutanized and the tissues adjacent to the implanted experimental plates were studied. During the whole period of the study a skin or local or general reaction was not observed. There was no difference in succinate-dehydrogenase activity that is a sign for preserved vital activity. The electron microscopic study of the cells in contact to the implant showed normal ultrastructure of the organelles. The results obtained from the histological, histochemical and electron microscopic study gave evidence for characterizing the alloy "Cristaloy 7-N" as one having high biocompatibility.