Influence of apical overinstrumentation and overfilling on re-treated root canals.
Explore the source record for details and available documents.
Follow-Up Studies↗
Biomedical subjects
G Bergenholtz
Publications and source records attributed to G Bergenholtz.
Retreatment of endodontic fillings.
Effects of endodontic retreatment on quality of seal and periapical healing were assessed among 660 previously root-filled roots. The roots were divided into either of two groups according to presence or absence of pathologic alterations in the periapical area. The retreatments, which were carried out by dental students, involved a thorough chemomechanical debridement of the root-canal system aiming to control infection. Following a 2-year observation period 556 roots were reexamined clinically and radiographically. The results showed that root-fillings with technical shortcomings could, following retreatment, be markedly improved as regards effectiveness of seal and distance to the apex. A large number of lumina discernible apical to root-filling could also be treated and filled. Seventy-eight percent of the cases with pathologic lesion present periapically prior to retreatment either completely healed or displayed an obvious size-reduction of the process. Retreatments carried out because of technical inadequacies alone were successful in 94% of the cases. It was concluded that renewed endodontic treatment whenever possible is the method of choice when treating defective endodontic fillings complicated with pathologic processes periapically. Apical surgery may be attempted if no signs of healing are apparent following observation.
Adult↗
Effect of experimentally induced marginal periodontitis and periodontal scaling on the dental pulp.
Experimental breakdown of the periodontal attachment apparatus was produced in six young adult monkeys to study the effect on the tissue of the dental pulp by (1) periodontitis, (2) scaling and plaque accumulation on exposed root dentin. Periodontal tissue breakdown was induced by the placement of ligatures around the neck of 92 permanent teeth. Subsequent plaque formation caused marked loss of periodontal tissue support, which after a period of 5--7 months amounted to 30--40% of the root length. One group of teeth received no further treatment. Other teeth were subjected to scaling and root planing. Following treatment, plaque was allowed to accumulate for 2, 10, and 30 days on the freshly planed root dentin surfaces. Histologic examination revealed that in comparison to teeth with normal periodontal conditions, 57% of the teeth exposed to periodontitis exhibited pathologic pulp tissue alterations. Secondary dentin formation and/or inflammatory cell infiltrates were observed within localized areas of the pulp subjacent to root surfaces exposed to periodontal tissue destruction. The changes within the pulp were of "mild" nature and only one tooth displayed signs of total pulp necrosis. Lateral canals communicating with both the pulp cavity and the exposed root surface were never detected. Teeth subjected to scaling and subsequent plaque accumulation in comparison with teeth with periodontitis alone exhibited no obvious aggravation or increased incidence of pathologic pulp reactions. The findings show that in the monkey (1) periodontal destruction limited to the cervical half of the root and (2) plaque accumulation on exposed root dentin does not cause severe alteration in the pulp of the roots involved.
Animals↗
Experimental pulpitis in immunized monkeys.
Bovine serum albumin (BSA) was topically applied to exposed dentin to assess whether inflammatory reactions can be induced in the pulp of monkeys immunized against BSA. Four cynomolgus monkeys received repeated injections of BSA emulsified with Freund's incomplete adjuvant. Pulp challenge was performed by applying BSA in freshly cut dentin cavities prepared on the buccal surface in 34 teeth. In 29 control teeth ovalbumin (OVA) was applied. Control applications of BSA were also performed in 15 teeth prepared in three nonimmunized monkeys. Forty-eight hours after the initiation of the pulp challenge the monkeys were sacrificed and the pulp tissue examined in the light microscope. Topical application of BSA to freshly exosed dentin in immunized monkeys resulted in severe inflammatory lesions in the pulp, characterized by bleeding and extravascular infiltration of large numbers of leukocytes. Extensive tissue damage was an important feature in several pulps. Identical applications of OVA in control teeth and BSA applications in nonimmunized monkeys produced no such reactions. The results indicate that interactions between antigens and antibodies can occur within the dentin-pulp area and following the formation of immune-complexes, severe injury to the pulp can be induced.
Administration, Topical↗
[Root canal therapy in Northern Europe].
Explore the source record for details and available documents.
Denmark↗
Effect of bacterial products on inflammatory reactions in the dental pulp.
Culture filtrates (extracellular components) and material obtained from disintegrated cells (intracellular components) of cultured plaque bacteria were studied for their capacity to induce inflammatory reactions in the dental pulp. Class V cavities were prepared on the buccal surface of 94 teeth: 42 test and 52 control teeth in six adult monkeys. lyophilized bacterial components were sealed into the test cavities either alone or following an 8-h topical application of a solution of the same components in phosphate-buffered saline (PBS). Culture medium and PBS were applied in two sets of control cavities. A third set was restored with zinc oxide-eugenol cement. The animals were killed 32 h after the initiation of the experiment and the pulps were examined histologically. Teeth treated trophil leukocytes in the area of the pulp subjacent to the cut dentin tubules. Abscess formation was frequently found. The severe reactions which developed were independent of differences between individual animals and differences in thickness of the remaining dentin. The controls showed damage to the odontoblasts but little or no neutrophil infiltration. The findings confirm that products of bacteria applied to exposed dentin initiate inflammatory reactions in the dental pulp.
Animals↗