摘要:

SummaryThe adaptation and sealing ability of a light‐cured glass ionomer cement when used as a retrograde root filling was assessed using a confocal optical microscope with and without a fluorescent dye. This material was compared with a conventional glass ionomer cement and amalgam. The root canals of 60 extracted human single‐rooted teeth were prepared and filled with gutta‐percha and sealer. All the teeth were apicected, retrograde cavities were prepared, and then divided into three groups of 20 teeth each and filled with the test materials. The light‐cured glass ionomer cement was well adapted to the retrograde cavity and apicected root surface. Within the retrograde cavity the cement was often well adapted to one wall, but gaps were found on the opposite cavity wall. This was probably caused by the polymerization contraction of the material. In contrast, the amalgam retrograde root fillings were poorly adapted to the cavines, with gaps between the cavity walls and amalgam. This group exhibited the poorest sealing ability as measured by the extent of dye penetration. The conventional glass ionomer cement was often found smeared over the root face, and there were unfilled voids at the base of some retrograde cavities. The results of the dye leakage study were analysed statistically The sealing ability of the light‐cured glass ionomer cement was significantly better than that of amalgam (P0.05). However, the sealing ability of the conventional glass ionomer cement was significantly better than that of amalg

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1991.tb01148.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryIt has previously been shown experimentally usingS.faecalisthat the relative number of blue‐staining Gram‐positive bacteria was reduced by demineralizing agents as well as by disinfection (Wijnbergen&van Muilera 1987, van Mullem&Wijnbergen 1989). In this study the cumulative effect of disinfection, experimental period, fixation and demineralization was investigated. The use of additives to the fixative and the demineralizing agents to limit the toss of bluestaining bacteria was also studied. The numbers of bacteria were determined using a haemocytometer, and the percentage of blue‐staining organisms were ascertained from smears.When compared with the start of the experiment, the sequence of disinfection with chlorhexidine, storage in PBS, fixation with neutral formaldehyde and demineralization with formic acid or EDTA appeared to reduce the relative numbers of Gram‐positive staining bacteria. For storage periods of 0 and 4 days the reduction factors were 100 and 600, respectively, using formic acid. These factors were 50 and 95, respectively, using EDTA. Addition of cetyl pyridinium chloride to the fixative and the demineralizing agents, and addition of neutral formaldehyde to the demineralizing agents lowered these reduction factors to 80 and 200, respectively, for formic acid, and 40 and 85, respectively, for EDTA.If the results are extrapolated to animal experiments where disinfection, experimental period, fixation and demineralization form part of the experimental framework, even the lowest reduction in the number of blue‐staining bacteria could lead to false interpretation of tissue

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1991.tb01149.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe cytotoxic effect of a zinc oxide‐eugenol‐based paste (Pulpispad) was evaluatedin vitroafter setting for 1 day and 1 week. Target cells were L929 cells, gingival, periodontal ligament and pulpal fibroblasts. The material was incubated with the cells for 4 and 24 hours, and its toxicity was evaluated with the51Cr‐release method. Puipispad was highly cytotoxic to all cell lines even after setting for 1 week. The use of Pulpispad is not recommended for future clinical application. The various responses among the four cell lines indicated that diploid cell lines can, under certain circumstances, be less sensitive than aneuploid cell lines. It is therefore suggested that in the evaluation of biomaterials the choice of cell lines should be carefully considered, as they can display varying sensitiv

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1991.tb01150.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryA clinical study of maxillary central incisors was conducted in order to evaluate the incidence of postoperative pain following one‐appointment root canal treatment using a modification of the double‐flared technique to prepare the root canal system. Sixty teeth with necrotic pulps, from 52 patients whose ages ranged from 10 to 53 years, were inciuded. Half of the teeth were prepared by the double‐flared technique, while the other half were prepared by a modification of this technique. No difference was observed in the incidence of postoperative pain between the two g

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1991.tb01151.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1991.tb01152.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1991.tb01153.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY