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Biomedical subjects

C F Marcinak

Publications and source records attributed to C F Marcinak.

3 recordsLinked to original sources

Preliminary studies of the histopathological responses to Ti-13% Cu casting alloys.

A preliminary study of some of the biological properties of a new dental casting alloy (Ti-13% Cu) was undertaken by employing the skeletal muscle implantation test in rabbits. Routine histopathological and chemical analysis techniques were utilized to study in vivo tissue reactions of skeletal muscle to this alloy. A moderately thick, somewhat cellular fibrous connective tissue capsule surrounded the implants after 2 wk. Remodelling of the fibrous tissue into a thin acellular tissue capsule occurred at 52 wk after implantation. Chemical analyses failed to detect deposition of either Ti or Cu corrosion products at the implant sites or within major organs.

Animals

Linear dimensional changes in addition curing silicone impression materials.

Five vinyl polysiloxane addition curing impression materials were evaluated on the basis of linear dimensional change occurring as a function of time between making an impression and pouring the die. The dies were measured and compared to a master model to determine the linear change in the impression material. One material produced an overall larger die, but the greatest increase in size deviated from the master model by only 0.1%. Permagum putty-wash material consistently produced undersized dies, with the greatest change being 0.3%. Three materials randomly produced smaller or larger dies, differing from the master model by only 0.08% for the smallest die to 0.07% for the largest. No consistent pattern of increase or decrease in die size occurred with time. Dies produced at 168 hours were as accurate as those produced at 10 minutes.

Chemical Phenomena

Linear dimensional changes in elastic impression materials.

Four classes of elastomeric impression materials (polysulfide, polyether, silicone, and agar-agar) were evaluated on the basis of linear dimensional stability as a function of time between taking and pouring an impression of mounted teeth. Four polysulfide materials produced dies which were larger than the teeth and generally increased in size with impression storage time. One silicone material produced dies slightly smaller than the teeth, and the dies from another silicone were dramatically smaller with increasing storage times. A polyether material produced slightly smaller dies for up to four hours' storage time, then increasingly larger dies up to 24 h. The dies from a reversible hydrocolloid were larger than the teeth for storage times up to 30 min, and then decreased rapidly at longer times.

Agar