Biomedical subjects

B R Rittman

Publications and source records attributed to B R Rittman.

3 recordsLinked to original sources

PubMed1992

Induced periapical lesions in ferret canines: histologic and radiographic evaluation.

Ferrets have been utilized in endodontic research to study periapical responses. However, various aspects of induction and healing of periapical pathosis in ferrets are unclear. This study evaluated the radiographic and histopathologic features of induced periapical lesions. Periapical pathosis was consistently produced in 8 canines of 2 ferrets by extirpating the pulp, leaving the cavities open for a week, then sealing for 12 weeks. The resulting lesions were evaluated radiographically every two weeks. The animals were then killed and the induced lesions evaluated histologically and histobacteriologically. Four untreated canines from 2 other ferrets were used as controls. Results showed that periapical rarefactions were visible in all teeth in the experimental group within 4 weeks. Histologically, the induced lesions consisted principally of a mononuclear inflammatory infiltrate, dominated by macrophages but with numerous lymphocytes. With Brown & Brenn staining, bacteria were demonstrated in the pulp space of teeth in which the lesions were induced and in the apical arborization of the canal system. Only one specimen had bacteria within the periapical lesion.

Animals↗

PubMed1979

Quantitative characterization of changes in cellularity and collagen fiber size in contracting palatal wounds.

Standard surgical wounds with either plain or undermined margins were created in the hard palates of 15 beagle pups by excising a strip of mucoperiosteum adjacent to molars. Healing was monitored, the pups were sacrificed at intervals from five to 31 days after surgery. Longitudinal data were collected for body weight and wound contraction. Examination of histologic sections of the wounds and adjacent tissues involved visual light microscopic assessments of fibroblast population density and computerized image analysis microscopy for quantification of population densities of three sizes of collagen fibers. Wounds with undermined margins showed less contraction than did those having plain margins. Findings on changes in the morphologic character of the maturing granulation tissues included quantitative documentation of (a) decreases in the population density of fibroblasts, (b) marked decreases in the number of thin (reticular) fibers, (c) marked increases in the number of medium sized fibers, and (d) slight increases in the number of coarse fibers.

Animals↗

PubMed1978

Dentinal crazing and interpin distance.

All three types of self-threading plus cause dentinal crazing. The frequency and degree of damage done to the dentin varies significantly between the three types of pins and depends upon the differences in the diameters of the drill and the pin. When two or more pins are placed in dentin, the potential for dentinal damage increases. Minikin pins (0.019-inch diameter) caused the least damage, in terms of both degree and frequency. The optimum and safe interpin distance using Minikin pins suggested by this study is 3 mm. Minim and Regular pins (0.023- and 0.031-inch diameters, respectively) caused more injury than Minikin pins. The Regular pins showed more damaging effects on dentin than Minim pins, both in terms of degree and frequency. On the basis of this study, the minimum interpin distance using Minim or Regular pins should be 5 mm. These minimum interpin distances are applicable only in situations where the dentin is not dehydrated or embrittled due to endodontic treatment. In teeth that have been endodontically treated, it would be advisable to use only the smallest self-threading pins and possibly increase the interpin distance if two or more pins are to be used.

Dental Pins↗