摘要:

SummaryThis study evaluated the preparation of root‐end cavities using an ultrasonically activated file, and the obturation of such cavities. In the first part, the root canals of 40 extracted teeth were prepared to size 40 and irrigated with NaOCl and EDTA. The root ends were resected and the teeth inoculated withEnterococcus faecalis, incubated for 10 days and divided into four groups: control; saline irrigation; hand instrumentation performed via a retrograde approach up to size 50 using saline irrigant; ultrasonic instrumentation with prebent size 40 K‐flex file inserted into a Piezon Master using saline irrigant. The teeth were fixed, sectioned longitudinally and viewed under scanning electron microscopy. Bacterial and smear layer scores were obtained at 1, 3, and 5 mm from the resected end. The bacterial scores for control and saline groups were similar; the scores for each instrumentation group were significantly lower than the control group (P<0.001), In addition, there were significantly fewer bacteria in the ultrasonic group compared with the hand instrument group (P<0.001), The smear layer scores for control and saline groups were similar, and significantly lower than in either instrumentation group (P<0.001). In the second part, root‐end cavities were ultrasonically prepared in 20 extracted teeth. Ten cavities were filled with amalgam, and 10 with thermoplasticized gutta‐percha and Grossman s sealer. After 24‐h storage, the root ends were immersed in dye for 48 h. Cross‐sectional slices of the obturated part of the root were evaluated using both light and confocal microscopy for dye leakage along the interface of filling material and dentine. There were no statistical differences between the leakage of amalgam and gutta‐percha root‐end fillings, nor between the two method

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00306.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe purpose of this study was to compare stiffness and resistance to fracture of four brands of nickel titanium K files. Instruments of sizes 15 to 40 were tested according to ANSI/ADA Specification No. 28. Resistance to fracture was determined by twisting and measuring the maximum torque and angular deflection at failure. Stiffness was determined by measuring the moment required to bend the instrument 45°. The permanent deformation angle remaining between the tip and the flutes of the instruments after bending ceased was also recorded. Nickel titanium K files satisfied and far exceeded specification standards for stiffness. They also satisfied and exceeded the standards for angular deflection at failure. They met or exceeded the maximum torque at failure standards in all sizes except for the size 40 of the Maillefer Niti, and the size 30 of the Mac Spadden Niti. Nickel titanium K files presented a null permanent deformation angle. Clinical studies are required to evaluate the influence of low bending moment on other properties such as breakage and canal transportation

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00307.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThis study examined the variety of obligate and facultative anaerobic bacterial species recovered from cases of acute apical periodontitis. A total of 19 root canal samples and 24 periapical granuloma samples were taken from patients suffering pain and discomfort. Bacteria were identified by applying the following techniques: culturing on various media, Gram‐staining and using commercially available biochemical test strips. In addition,Prevotella intermedia and Porphyromonas endodontaliswere differentiated on a molecular genetic level using species‐specific oligodeoxymicleotide probes. The most frequently identified bacteria were Prevotella intermedia,Bifidobacterium spp., Streptococcus sanguis. Streptococcus milleri‐group and Bacteroidesspp. Obligate anaerobes occured at a rate of 82.3%, and the average number of isolates was 6.4 per s

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00308.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryOne hundred and ninety‐five teeth in 35 patients with periodontitis who had received both endodontic and periodontal treatment were evaluated 9 years after endodontic treatment and 8 years after periodntal treatment. Some 91.4% of cases were well maintained and 8.6% showed a deterioration in their periodontal condition. Twelve of the 195 teeth with endodontic treatment were lost, eight for periodontal codition. Twelve of the 195 teeth with endodontic treatment were lost, eight for periodontal reasons, three as a result of fracture and one because of caries, and the periodontal condition of 10 teeth had worsened. An apical lesion formed on one tooth. The results indicate that the risk of endodontic failure in this group of 195 teeth is very low, and that there is little risk of tooth loss for periodontal reasons, provided that the patients receive suppportive periodontal treatmen

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00309.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThis paper describes a case in which the radiographic appearance of a resorptive lesion in a mandibular incisor tooth posed difficulty in the diagnosis of its origin. The lesion did not conform to the normally accepted criteria for diagnosis of internal resorption. Clinical examination did not support the diagnosis of external cervical resorption. Serial histological section of the extracted tooth subsequently confirmed the diagnosis of internal resorption. The criteria for differential diagnosis of resorptive lesions with smooth outlines in the cervical regions of teeth are discussed together with the rationale for their management.

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00310.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe purpose of this prospective study was to assess the incidence of flare‐ups (a severe problem requiring an unscheduled visit and treatment) among patients who received endodontic treatment by the two authors in their respective practices during a period of one year, and also to examine the correlation with pre‐operative and operative variables. The results showed an incidence of 1.58% for flare‐ups from 1012 endodontically treated teeth. Statistical analysis using the chisquare test (P<0.05) indicated that flare‐ups were found to be positively correlated with multiple appointments, retreatment cases, periradicular pain prior to treatment, presence of radiolucent lesions, and patients taking analgesic or anti‐inflammatory drugs. In contrast, there was no correlation between flare‐up, and age, sex, different arch/tooth groups and the status

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00311.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe objective of this study was to compare the adaptation of mechanically softened gutta‐percha to the root canal wall in the presence and absence of smear layer. The root canals of 20 freshly extracted human maxillary incisors were cleaned and shaped. Prior to obturation, 10 root canals were irrigated with 20 ml of 50% citric acid followed by 20 ml of 5.25% sodium hypochlorite. All canals were obturated with mechanical compaction of gutta‐percha and AH‐26 sealer. After 72h, each tooth was fractured in half. Scanning electron microscopy demonstrated that the sealer had formed a continuous layer in contact with the canal walls, becoming progressively thinner towards the apex. The sealer pentrated into the dentinal tubules along with projections of gutta‐percha only in those teeth without smea

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00312.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00313.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00314.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY