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Biomedical subjects

M Peleg

Publications and source records attributed to M Peleg.

64 records · Page 4Linked to original sources
PubMed1979

Measurement of the inactivation kinetics of poliovirus by ozone in a fast-flow mixer.

Inactivation kinetics of poliovirus type 1 in ozone demand-free water was investigated by utilizing a fast-flow mixing apparatus. Ozonated water and a solution of ozone demand-free water containing a known quantity of poliovirus type 1 were introduced simultaneously into a mixing chamber, both at a constant rate. This mixture was then passed through a narrow tube of known length and diameter into a neutralizing solution. By altering the rate of introduction and/or tube length, different contact periods between ozone and virus could be determined with an accuracy of 0.01 s. Inactivation of the poliovirus occurred in two steps. During the first step, which lasted for 0.2 to 1.0 s, 95 to 99% of the virus was inactivated, depending on the ozone concentration (which ranged from 0.1 to 2.0 mg/liter). The second step apparently continued for several minutes; in this period the remainder of the virus was inactivated. An obvious dose-response relationship was demonstrated during the first step of the inactivation curve. The pH of the water slightly affected the viral inactivation rate, but these small differences seem to have no practical value.

Buffers↗
PubMedDate not supplied

Mechanical properties of hydrocolloid gels filled with internally produced CO2 gas bubbles.

Agar (2%), alginate (1% algin), and kappa-carrageenan (1.5%) gel specimens were prepared from mother solutions that contained 0-2.5% sodium bicarbonate (agar and carrageenan) or calcium carbonate (alginate). Upon immersion in a citric acid bath (0-2%), the carbonate reacted with the diffusing acid to produce numerous carbon dioxide bubbles. The compressive strength and deformability of the gas-filled gels so produced were determined using a Universal testing machine and compared with those of pure gels and gels containing the carbonate but not subjected to the process after various immersion times. While the agar and alginate gels retained considerable mechanical integrity even after several hours, the carrageenan gels disintegrated after about 2-5 h. Under similar conditions, the number of bubbles produced in the agar gels was about twice that in the alginate gels, an observation that cannot be explained solely by stoichiometric considerations.

Agar↗
PubMedDate not supplied

Sinus augmentation for single-tooth replacement in the posterior maxilla: a 3-year follow-up clinical report.

A technique for single-tooth sinus lift and simultaneous implant placement in the posterior maxilla is presented. Ten hydroxyapatite-coated cylindric implants, 13 to 15 mm in length, were placed together with a composite bone graft of demineralized freeze-dried bone allograft and autogenous bone in 10 adults. Surgical technique and anatomic considerations are discussed. Follow-up of 3 years showed successful function and no cervical bone loss in all patients.

Adult↗
PubMedDate not supplied

Augmentation grafting of the maxillary sinus and simultaneous implant placement in patients with 3 to 5 mm of residual alveolar bone height.

This study assessed the efficacy of augmentation grafting of the maxillary sinus with simultaneous placement of dental implants in patients with less than 5 mm of alveolar crestal bone height in the posterior maxilla prior to grafting, although the procedure has traditionally been contraindicated based on empirical data. A total of 160 hydroxyapatite-coated implants was placed into 63 grafted maxillary sinuses in 63 patients whose crestal bone height in this region ranged from 3 to 5 mm. Patients were followed for 2 to 4 years after the placement of definitive prostheses. There were no postoperative sinus complications. Following uncovering of the implants at 9 months after surgery, there was no clinical or radiographic evidence of crestal bone loss around the implants. Histologic examination of bone cores from the grafted sites revealed successful integration and a high degree of cellularity. All patients maintained stable implant prostheses during follow-up. These findings indicate that the single-step procedure is a feasible option for patients with as little as 3 mm of alveolar bone height prior to augmentation grafting, utilizing hydroxyapatite-coated implants and autogenous bone.

Adult↗