Histologic study of pulp capping using chlorhexidine in dogs.

This histological study was conducted to compare the pulp reactions to chlorhexidine and calcium hydroxide. Twenty permanent premolar teeth of beagle dogs were mechanically exposed under aseptic conditions. The pulp was then capped with one of the following: chlorhexidine 0.2% on the left side and calcium hydroxide (dycal) on the right side of the same dog. Maxillary second premolars were extracted from each dog three weeks after the pulp capping procedure. Maxillary third premolars and mandibular first premolars were extracted at 6 weeks and 9 weeks respectively. The mandibular second premolars were extracted three months after the pulp capping procedure. The specimens were fixed in 10% formalin and decalcified in 5% formic acid. Serial sections, 7 microns thick, were prepared and stained with hematoxylin and eosin. Teeth treated with chlorhexidine or with calcium hydroxide were well tolerated by the dental pulp at 3 and 6-week intervals. Pulps treated showed satisfactory pulp reaction and the odontoblastic layer appeared to be normal and in its configuration. Inflammatory response was not present at the 6-week time interval. At nine weeks, the inflammatory response was severe in those teeth treated with calcium hydroxide. There were no remarkable histological differences among the treatment groups at 12 and 15 weeks. These specimens showed complete loss of pulpal architecture. Regressive changes were seen and microscopic specimens revealed presence of spaces and intertwining bundles of films in the pulp.

Quantitative triple fluorochrome labeling study of lathyritic-rat mandible.

The present study was conducted to quantify the amount and distribution of new bone formation by triple fluorochrome labeling sequence in different areas of the mandibular bone of the control and lathyritic animals. The data was subjected to statistical analysis. Osteolathyrism significantly impaired the turnover and remodeling rates of periosteal and endosteal bone. The fluorescent bands were distinct and wider in the control than in the experimental animals. Mean ratio values for labeled bone showed considerable variations in different regions and age groups. The amount of labeled bone in the condyle and molar region of control animals was 1.49 to 1.77 and 1.41 to 1.78 times higher than in the lathyritic animals.

Histologic study of pulp capping in rat molars using calcitonin.

Calcitonin, a calcium regulating hormone, has been found to affect bone formation and resorption. In this study a calcitonin preparation and a calcium hydroxide preparation for comparison were applied to both exposed and unexposed rat molar pulps. Histologic examinations were conducted after periods of 1 day to 28 days. Calcium hydroxide pulp caps produced varying amounts of secondary dentin and inflammation. Calcitonin applied as an indirect agent had a similar effect. When calcitonin was applied to exposed pulp, a large amount of dense fibrous connective tissue reminiscent of scar tissue was formed. With increased time this connective tissue exhibited signs of progressive, orderly calcification continuing through a large portion of the coronal pulp.

Mandibular condylectomy in the guinea pig: quantitative triple fluorochrome study.

Different-colored fluorochromes were administered sequentially to guinea pigs and the rate of bone formation measured in their condylectomized control contralateral hemimandibles. The values for labeled bone for condylectomized hemimandibles were lower than for the control contralateral hemimandibles of the same guinea pig. The differences in values of condylectomized and control contralateral sides for DCTC- and total surface area-labeled bone were statistically significant, but were not statistically significant for DCAF- and hematoporphyrin-labeled bone. There was partial regeneration of the condylar process. Although the condylectomized area was nearly normal in shape, its size and proportions were different from those of the contralateral hemimandibles that were not operated on. The greatest differences were noted in the length, height, and the distances measured between the inferior alveolar foramen and the mental foramen and the posterior border of the condyle.

Long-range effects of Ivalon sponge containing isobutyl cyanoacrylates on rat tissue. A quantitative planimetric study.

This study on seventy rats was undertaken to determine the long-range effects of Ivalon sponge containing isobutyl cyanoacrylates (IBC). Histologic examination revealed that IBC sponge was well tolerated by the connective tissue. IBC sponge was most effective during the first 2 weeks of healing. At observation periods of 1 and 2 weeks, the percentage values for connective tissue formed in IBC-treated animals were 2.02 and 1.58 times higher than those in the untreated animals.