Robert M. Block

A histopathologic and histobacteriologic study of 35 periapical endodontic surgical specimens

Biopsy specimens were obtained, during endodontic surgical procedures performed on 35 patients. Histopathologic and histo bacteriologic studies of the specimens showed that there was no correlation between the presence of various inflammatory cells and the clinical signs and symptoms of the patients. Epithelium was found in 21 specimens, but only nine lesions were diagnosed as cysts. Although bacteria were found in five specimens, in only one case were the bacteria located in the disintegrating tissue of the root canal and periapical tissue.

A histopathologic, histobacteriologic, and radiographic study of periapical endodontic surgical specimens

Data available on 230 periapical endodontic surgical specimens were studied. It was found that bacteria occurred in the periapical tissue very infrequently. In addition, there was no correlation between the presence of acute inflammatory cells and the presence or absence of pain. Granulomas with epithelium occurred in 61 out of 230 cases, while 14 of these were cysts. Of the 110 cases with radiographic follow-up data, 67 were classified as successful, 40 were uncertain, and 3 were unsuccessful according to a modification of Strindbergs criteria, whereas 107 would have been successes according to the criteria of Bender and Seltzer and their associates. No valid biologic or clinical basis for endodontic therapy as suggested by Bhaskar was found in this material.

Nonrecognition and subsequent endodontic treatment of dens invaginatus

Summary A case of dens invaginatus resulting in periapical pathosis has been reported. The nonrecognition of this developmental anomaly and its consequences led to inappropriate treatment. The importance of early and correct diagnosis, the possible significance of even a small and noncariousdens invaginatus, and the treatment of the anomaly with nonsurgical endodontics were stressed.

Cell-mediated immune response to dog pulp tissue altered by Formocresol within the root canal

Pulp tissue from three experimental dogs was tested for its antigenicity before and after incubation with Formocresol. Cell-mediated skin test reactions showed an increased response to pulp that had been altered by Formocresol and injected as compared with Formocresol alone. In vitro analysis of cell-mediated immune response (lymphocyte proliferation) showed a noticeable increase when pulp was incubated with Formocresol as compared with the salinetreated pulp (P

Systemic distribution of [14C]-labeled paraformaldehyde incorporated within formocresol following pulpotomies in dogs

Following pulpotomy procedures, using[ 14 C]-labeled paraformaldehyde formocresol, [ 14 C]-labeled paraformaldehyde was found in the blood, regional lymph nodes, kidney, and liver. Histological examination demonstrated severe tissue destruction at the pulpotomy site and the apical tissues, where disintegration products spread by circulation.

Antibody formation to dog pulp tissue altered by N2-type paste within the root canal

Pulp tissue from three experimental dogs was tested for its antigenicity before and after incubation with an N2-type paste. Arthus reactions to skin, tests showed an increased response to pulp that had been incubated in N2-type paste and washed then injected as compared with the N2-type paste alone. Hemagglutinating antibody titers (1:180 to 1:320) were obtained from pulp tissue altered by N2. Inhibition tests showed the specificity of the antibody to be at a dilution titer of 1:250. Therefore, N2-type paste altered dog pulp tissue and rendered it antigenically active, and a specific humoral response was produced.

Antibody formation to dog pulp tissue altered by eugenol within the root canal

Pulp tissue from three experimental dogs was tested for its antigenicity before and after incubation with eugenol. Arthus skin test reactions showed an increased response to pulp that had been altered by eugenol and injected as compared with eugenol alone. Hemagglutinating antibody titers (1:360 to 1:600) were obtained to pulp tissue altered by eugenol. Inhibition tests showed the specificity of the antibody to be at a dilution titer of 1/250. Therefore, eugenol altered dog pulp tissue, rendered it antigenically active, and produced a specific humoral response.

Cell-mediated immune response to dog pulp tissue altered by 6.5% paraformaldehyde via the root canal

Pulp tissue from three experimental dogs was tested for its antigenicity before and after incubation with 6.5% paraformaldehyde. Reactions to cell-mediated skin tests showed an increased response to pulp that had been incubated in paraformaldehyde, washed, and then injected, as compared with pulp or paraformaldehyde alone. In vitro, analysis of cell-mediated immune response (lymphocyte proliferation) showed a distinct increase when pulp tissue was incubated in paraformaldehyde and washed as compared with saline-treated pulp. The increase in radioactivity was statistically significant at P

Endodontic surgical re-treatment—A clinical and histopathologic study

Biopsy specimens were obtained during endodontic surgical re-treatment procedures performed on 35 patients. Results of histopathologic and histobacteriologic studies of the specimens showed that there was no correlation between the presence of various inflammatory cells and the clinical signs and symptoms of the patients. In addition, no correlation was found between the radiographic appearance and the histologic picture. Epithelium was found in five specimens, but only two lesions were diagnosed as developing cysts. Although bacteria were found in three specimens, in no case were the whole bacteria located in the periapical tissue.

Retrograde amalgam procedures for mandibular posterior teeth

Summary This article has reviewed the indications, armanentarium, and the special techniques used in retrograde amalgam procedures on mandibular molars. Special emphasis was placed on the techniques used to obtain surgical access, beveling of the root apex, and cavity preparations for retrograde amalgams. The importance of the endodontists role and case selection have been emphasized. The authors thank Dr. I. B. Bender for his advice and suggestions, and Donna Fiori, Kathy Gerstheimer, and Audrey Troy for their aid in preparation of this manuscript.