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Biomedical subjects

M H Amler

Publications and source records attributed to M H Amler.

17 recordsLinked to original sources
PubMed1992

Peripheral giant cell granuloma.

A case report of an occurrence of peripheral giant cell granuloma becomes unusual because the patient appears to have experiences root resorption as well.

Aged↗
PubMed1990

Hard tissue replacement (HTR) polymer as an implant material.

This study aimed to evaluate the effectiveness of a synthetic implant material Hard Tissue Replacement polymer (HTR) for: (1) compatibility with bone and soft tissues, (2) capacity to physically attach to bone and soft tissues, and (3) capacity for bone induction and metaplasia. HTR was implanted for a 3-week test period in femur bones, connective tissue, and skeletal muscle of 15 Sprague-Dawley descent rats for histological examination and implanted in bone in 6 rats for infrared absorption analyses to determine the presence of new bone. Compatibility (defined as absence of significant inflammation) was present in 13/14 (93%) bone sites, 7/9 (78%) connective tissue, and 4/4 (100%) muscle sites. Physical attachment of HTR occurred in 10/14 (71%) bone sites, 4/9 (44%) connective tissue, and 1/7 (14%) muscle sites. Density of new bone appeared to be greater with HTR than in controls. However, no metaplastic bone was formed in nonbony sites indicating that this material is nonosteogenic. These preliminary findings demonstrated the effectiveness of HTR as an implant material.

Animals↗
PubMed1987

Osteogenic potential of nonvital tissues and synthetic implant materials.

Following the application of various techniques to restore or rebuild alveolar bone with different implants, results are generally unpredictable. In successful cases it is not clear whether the materials are capable of initiating osteogenesis by metaplastic induction, where endogenous bone formation had failed, or initiating osteogenesis by stimulating the regeneration of existing vital bone tissue by irritation. In order to discriminate between these two possibilities, 40 Sprague-Dawley descent rats were implanted with both devitalized tissues and synthetic materials in an area where bone is not usually formed: the anterior eye chamber. The test materials consisted of two devitalized tissues: boiled bone marrow and demineralized dentin, and six synthetic materials: formalin 10% and 40%, formic acid 10% and 88%, plaster of Paris, and ceramic tricalcium phosphate (Durapatite). Test materials were inserted into 59 chambers, but bone was not formed in any of these cases following a three-week experimental test period. Following implantation of 21 control chambers with viable mature marrow, bone was formed in 5 of 21 cases (24%), following the three-week test period. These findings appear to indicate that the reported cases where bone regeneration successfully occurred following implantation probably resulted from unpredictable irritational factors upon the existing vital bone tissue rather than by metaplastic induction.

Animals↗
PubMed1984

The effectiveness of regenerating versus mature marrow in physiologic autogenous transplants.

Differences in rates of bone healing in animals and in human extraction wounds suggest that marrow tissue is more likely to form bone when transplanted at the onset of its most active regenerative period rather than at its maturity. To test this hypothesis, small segments of polyvinyl sponge were implanted into experimentally produced femur cavities in Sprague-Dawley rats, to provide matrices for regenerating cellular structure in the grafting procedures. Bone resulted in 16 of 22 cases (72.7%) in which regenerating marrow was transferred to the anterior eye chamber, compared with 4 of 23 cases (17.4%) in which mature marrow was used (P = 0.0002). No bone resulted when washed, polyvinyl sponge samples were implanted as controls in 6 cases. These findings indicate that with existing techniques it is probably more effective to transplant regenerating marrow than mature marrow.

Animals↗
PubMed1980

Osteopoietin-humoral induction factor in osteogenesis.

A heat-stable, glycoprotein-like material, osteopoietin, produced during bone marrow regeneration, has been shown to induce bone formation when implanted in the rat eye. The material was separated by ultrasonic treatment or by acid buffer (pH 3-5) from sponges implanted in the marrow. The extracted material free of bone or cell solids, induced bone formation in the anterior eye chamber of the rat, whereas the cell solids and control sponges similarly implanted did not.

Animals↗
PubMed1977

The age factor in human extraction wound healing.

Age as a factor in extraction wound healing was studied. The healing time in individuals in the second decade of life was compared to that in individuals in the sixth decade and older. In the first ten-day postextraction period, no significant differences in the rate of healing between young and older individuals was noted. At approximately ten days, the rate of regeneration of the tissues of younger individuals began to accelerate. At approximately 20 days, after a lag phase, the rate of regeneration of tissues of older individuals began to accelerate. At approximately 30 days, the rates of healing were equal between young and older individuals. These findings of the period of most active regeneration of reparative marrow tissue in younger and older individuals may have significance in the timing of donor material in marrow transplant procedures. This aspect is currently under investigation.

Adolescent↗