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Biomedical subjects

R Liberman

Publications and source records attributed to R Liberman.

66 records · Page 4Linked to original sources
PubMed1977

Effect of local application of fluoride on healing of experimental bone fractures in rabbits.

The effect of local application of low fluoride concentrations on the healing of experimental bone-radii fractures in 20 rabbits was examined. No external fixation was required after the osteotomy and gelfoam being used as a medium for fluoride application. Histologic mineral and mechanical strength measurements were carried out on the healing callus. There were no significant changes in the ashpercentage and the fluoride concentration of the ash between the experimental and control callus. A significantly higher percentage of ossified tissue was found in the fluoride treated callus. The breaking strength was found to be significantly higher in the bone fractures treated with fluoride, whereas there was no notable difference between the surface areas. It is postulated that the greater amount of ossified tissues, the differences in organization of the bone trabecules, and/or an improved mineral crystallinity may be responsible for this result.

Animals↗
PubMedDate not supplied

Surface treatment of mercury-free alloys.

Finishing and polishing methods were examined for two metallic direct restorative materials being proposed as possible alternatives to amalgam, namely a gallium alloy and a consolidated silver alloy. The polished surfaces were compared to a conventional spherical amalgam (Tytin). After initial surface treatment with a 12-fluted tungsten carbide bur in a high-speed dental hand-piece, three polishing methods were evaluated: slow-speed polishing burs, rubber polishing points, and polishing disks (Sof-Lex). Each of these methods was followed by an additional surface treatment in which a pumice-flour/water slurry was applied with a rotary brush and a final surface treatment with a zinc-oxide/ethanol slurry that was applied with rotary rubber cups. The surface roughness was evaluated by profilometric measurements and light microscopy. The results showed that the smoothest surfaces for all metals were achieved with rotary finishing and polishing disks. Using the rubber points resulted in surfaces that were statistically similar to the disk-polished surfaces on all three materials. The polished surface of gallium alloy was consistently slightly rougher than that of amalgam. The consolidated silver also presented a consistently rougher surface than did amalgam, although these differences were not statistically significant. The additional polishing with pumice and zinc oxide improved the luster, but did not significantly improve the measured surface smoothness in any of the restorative materials studied.

Dental Alloys↗
PubMedDate not supplied

Glass ionomer cement restorations: the effects of lasing the cavity walls on marginal microleakage.

Glass Ionomer cements are used in modern dentistry for various preventive purposes, one of which is the treatment of cervical caries lesions. Anticariogenic properties and the ability to bond to dentin and enamel are their main advantages. Since acid-etching of the tooth prior to glass ionomer placement is contraindicated, a "dry" defocused laser beam was used to enhance retention. The results indicate that finishing the cavity walls with a laser beam increased the marginal microleakage of the glass ionomer cement restorations. Thus, the procedure was apparently found unsuitable for clinical use.

Dental Cavity Preparation↗