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Biomedical subjects

M D Rohrer

Publications and source records attributed to M D Rohrer.

15 recordsLinked to original sources
PubMed1992

The cutting-grinding technique for histologic preparation of undecalcified bone and bone-anchored implants. Improvements in instrumentation and procedures.

An improved technique for histologic sectioning of hard tissues is described. Thin sections (5 to 15 microns) of undecalcified tissues such as bones with ceramic and metallic implants as well as teeth with enamel and fillings can be produced. Implant-tissue and hard tissue-soft tissue interfaces are well preserved. Because of the development of equipment and materials designed specifically for this technique, consistently good results are obtained. Most stains used in the paraffin technique may also be used in these sections.

Animals↗
PubMed1987

A histologic evaluation of a mandibular cross section one year after augmentation with hydroxyapatite particles.

A pathologic mandibular fracture in a 35-year-old woman 1 year after the attempted filling of a bone defect with particulate, dense hydroxyapatite resulted in a partial mandibular resection, allowing observation of cross sections of the mandible and associated soft tissue. Thin tissue sections were examined without decalcification. This permitted excellent observation of the hydroxyapatite particles, the bone, and the soft tissue. Osseointegration had occurred only in the areas closely associated with the bone. The immobility of the particles was a prerequisite for involvement with new bone formation. Hydroxyapatite particles in areas that allowed any mobility were surrounded by connective tissue with no bone formation evident. Heterogeneous particles were observed, indicating the possibility of a lack of purity in the hydroxyapatite ceramic, which may have contributed to the resorption of the particles. These findings, as well as other clinical and experimental findings, lead us to question the concept of hydroxyapatite as a bioactive ceramic that induces osteogenesis or osteoconductivity.

Adult↗
PubMed1986

Microwave sterilization of hydrophilic contact lenses.

We used standard 2,450-MHz microwave irradiation to achieve sterilization of hydrophilic contact lenses contaminated with a variety of bacterial, fungal, and viral corneal pathogens. A three-dimensional rotisserie was used to overcome the problem of "cold spots" within the microwave oven. The contact lenses became dehydrated in approximately two minutes. Rehydration with normal saline restored their shape and appearance. The time necessary to prohibit all growth of the bacterial and fungal organisms studied ranged from 45 seconds to eight minutes. All viral contaminants were completely inactivated after four minutes of microwave exposure. Refractive properties were unaffected after 101 exposures to microwaves for ten minutes. Slit-lamp examination and scanning electron microscopy disclosed minute particles on the surface of these contact lenses but no damage to the lens matrix from irradiation.

Bacteria↗
PubMed1985

Microwave sterilization of nitrous oxide nasal hoods contaminated with virus.

Although there exists a desire to eliminate the possibility of cross-infection from microbial contaminated nitrous oxide nasal hoods, effective and practical methods of sterilization in a dental office are unsatisfactory. Microwaves have been used to sterilize certain contaminated dental instruments without damage. In this study nasal hoods contaminated with rhinovirus, parainfluenza virus, adenovirus, and herpes simplex virus were sterilized in a modified microwave oven. Ninety-five percent of the virus activity was destroyed after 1 minute of exposure of the contaminated nasal hoods to microwaves. By the end of 4 minutes, complete inactivation of all four viruses was found. Repeated exposure of the nasal hoods to microwaves resulted in no damage to their texture and flexibility. Microwave sterilization may potentially provide a simple and practical method of sterilizing nitrous oxide anesthesia equipment in a dental or medical practice.

Adenoviruses, Human↗
PubMed1985

Comparison of meclofenamate sodium with buffered aspirin and placebo in the treatment of postsurgical dental pain.

The efficacy of meclofenamate sodium (Meclomen) at two different doses was compared with that of buffered aspirin and placebo in the control of postsurgical pain in a double-blind, randomized study of 205 patients. Meclofenamate sodium, 200 mg, was significantly better than meclofenamate sodium, 100 mg, in some efficacy parameters. Both doses of meclofenamate sodium were superior to buffered aspirin in most parameters of efficacy, and more effective than placebo in every parameter.

Acetaminophen↗
PubMed1985

Microwave sterilization.

This study has shown that representative fungi, viruses, and aerobic and anaerobic bacteria, including spore formers, can easily be killed in a conventional microwave oven with proper modifications. Metal instruments, including air turbine handpieces and burs, and acrylic dentures can be sterilized in short periods. Consistent sterilization can be accomplished only if the items to be sterilized are rotated in a three-dimensional manner throughout the microwave cavity. Arcing back to the magnetron and damage to the microwave oven are prevented by placing a radar absorbent material within the oven and with proper insulation of the item to be sterilized.

Bacteriological Techniques↗