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Biomedical subjects

K Langeland

Publications and source records attributed to K Langeland.

17 recordsLinked to original sources
PubMed1991

Tissue reaction to endodontic materials: methods, criteria, assessment, and observations.

The purpose of this study was to develop methods and criteria for the testing of the biocompatibility of endodontic materials. One hundred twenty-one teeth from 12 baboons (Papio anubis) were used to test three sealers: AH26, Kerr pulp canal sealer, and Kloroperka N.O. Gutta-percha cones were used as solid core in all cases. Under disinfected conditions, access preparation was performed, and with working length approximately 1.0 mm short of the foramen, the instrumentation of the root canal was started, using sodium hypochlorite (1%) for irrigation. After the root canals were cleaned and shaped, they were obturated with gutta-percha cones and the sealer, and by lateral condensation technique. Histologic periapical reactions were evaluated at 1, 7, 30, 365, 730, and 1095 days. The methods and criteria used were adequate for ranking of the biocompatibility of the tested materials in the short and long periods. At short observation periods (1 to 7 days) AH26 caused severe reactions, and Kerr pulp canal sealer and Kloroperka N.O., moderate and mild reactions, respectively. At 2- and 3-year observation periods the ranking was AH26, mild; Kerr pulp canal sealer, moderate; and Kloropercha N.O., severe.

Animals↗
PubMed1991

Clinical, radiographic, and histologic study of endodontic treatment failures.

One hundred fifty cases of endodontic treatment failures were studied clinically, radiographically, and histologically. Fifty-seven percent of the teeth were asymptomatic. Pain alone and/or associated with swelling was present in 21% of the teeth. There was no correlation between the size of periradicular rarefaction and the occurrence or severity of clinical signs and/or symptoms. Stainable bacteria were demonstrated in 69% of the teeth and were present mostly in the canal. The severity of periradicular inflammation was related to presence of stainable bacteria in the canal. Swelling and pain or a draining sinus tract was often associated with stainable bacteria inside the canal. The development of a radicular cyst associated with an endodontically treated tooth that has failed is not necessarily the cause of endodontic treatment failure.

Dental Pulp Cavity↗
PubMed1990

[Pulpal-periapical response to canal medication with Ca(OH)2].

This study consisted of biopsies of teeth and root tips removed after Ca(OH)2 therapy. The teeth were clinically intact or exposed to caries, trauma, and/or iatrogenesis. Following the therapy most of the canal walls were clean, but the canals contained varying amounts of pulp tissues, debris and Ca(OH)2 particles. In one case microrganisms were present in the apical part of the canal, but not beyond the foramen. The Ca(OH)2 therapy was efficient for its purpose.

Adult↗
PubMed1990

Root canal dentinal tubule disinfection.

Dentinal tubules of the root canal walls of human teeth were infected in vitro with a known bacterial isolate. The roots were exposed to either calcium hydroxide or iodine potassium-iodide for various periods of time and the viability of microorganisms was determined by incubation of entire root samples in a culture medium. The effects of the two agents on microbial viability were evaluated and compared. Iodine potassium-iodide disinfected dentin effectively. In contrast, bacteria remained viable in the dentin after relatively extended periods of calcium hydroxide treatment.

Calcium Hydroxide↗
PubMed1990

Prevalence of previous endodontic treatment, technical standard and occurrence of periapical lesions in a randomly selected adult, general population.

A random sample of 967 subjects selected from the total population in a Swedish county were examined radiographically regarding prevalence and quality of endodontic treatment and occurrence of periapical lesions. The relationship between the technical standard of endodontic treatment and the occurrence of periapical lesions was also analyzed. Of the selected individuals, 95% attended examination (751 dentate and 169 edentulous individuals). Of the 17,430 teeth examined, 1,492 (8.6%) were endodontically treated. Approximately 70% of the treated root canals were inadequately obturated; 10% showed excess of root filling beyond the apex. The prevalence of periapical lesions was 2.9%, and 24.5% of the endodontically treated roots demonstrated periapical lesions. Root fillings ending more than 2 mm from apex had a significantly lower frequency of periapical lesions than root fillings ending within 2 mm of the apex. No difference in the frequency of periapical lesions was found between properly and improperly obturated root canals. Excess of root filling material beyond the apex was related to a significantly higher frequency of periapical lesions.

Adult↗
PubMed1978

Pulpal response to the application of phosphoric acid to dentin.

Experimental cavities were prepared in forty-six clinically intact premolars of young individuals to evaluate the biologic effects of 50 per cent phosphoric acid etchant containing 7 percent zinc oxide by weight. The experimental periods ranged from 30 minutes to 150 days. The remaining dentin thickness varied from 1.8 to 3.5 mm. The teeth treated with the acid showed no more than a moderate pulpal response at the varying time periods. All of the acid-treated teeth demonstrated pulpal imflammation in the absence of clinical pain. Acid etchants should not be used on exposed or unprotected dentin surfaces.

Acid Etching, Dental↗
PubMed1977

Corticosteroids in dentistry.

The application of corticosteroids to cut dentine following cavity preparation, to carious dentine in indirect pulp capping, to the exposed pulp or to pulp remnants and periapical tissues during root canal therapy has been claimed to eliminate post operative pain and inflammation. Other investigators have thrown doubt on the validity of these claims and have reported continued inflammation progressing to necrosis following such applications. This paper reports detailed clinical and histological findings in a series of over 500 teeth some of which received conventional treatment while others were treated with various corticosteroids including Mosteller's solution, tritiated prednisolone, and Ledermix paste and cement. The results confirm the fact that no clear correlation exists between symptoms and histological findings in pulp disease. The absence of pain following application of corticosteroids cannot therefore be taken as evidence of a specific therapeutic effect. In some cases pain returned after a period and histologic examination showed the slow development of inflammatory changes coupled with calcification in pulp tissue and on the walls of the canal. Further investigation is needed to clarify the relative contribution of the removal of toxic products by instrumentation and the anti-inflammatory properties of corticosteroids in the reduction of pain of pulpal origin.

Adrenal Cortex Hormones↗
PubMed1976

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 Strindberg's 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.

Connective Tissue↗