摘要:

SummaryThe aim of thisin vitrostudy was to test the ability of a novel non‐instrumental technique to prepare and obturate root canals. Cleaning of the root canal system was achieved with a device which was able to develop, under reduced pressure, controlled cavitation. The same device was used for proper drying and subsequent obturation of the root canal system. A total of 55 freshly extracted molars with 120 canals were treated either by the step‐back technique and lateral condensation of gutta‐percha and AH26 as a sealer or by the new device. The teeth were then sectioned horizontal to the long axis of the root canal and examined by light microscopy. The cross‐sectional area, area with residual pulpal tissue and voids were assessed morphometrically. Overall, the treatment with the new device resulted in similar cleanliness and obturation quality when compared with the control group. Total treatment time using the new non‐instrumental technique, however, was less than half of that using hand instru

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00148.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryCalcium hydroxide has been advocated for use in avulsed teeth as a temporary dressing in an attempt to prevent or inhibit external resorption. However, there have been no long‐term histological studies that have examined gutta‐percha versus calcium hydroxide treatment in avulsed teeth. The purpose of this study was to determine the long‐term therapeutic effect of calcium hydroxide therapy in avulsed teeth. Six adult macaca monkeys were anesthetized and all four maxillary incisors were extracted and bench‐dried for 25 min. The teeth were replanted and splinted with composite for approximately 2 weeks. Each animal served as its own control and the teeth were accessed, instrumented, and filled with either Ca(OH)2or gutta‐percha and AH26 cement. All access openings were filled with composite. The Ca(OH)2was replaced twice during the experimental period (approximately every 8 weeks). The animals were killed between 5 and 7.5 months postavulsion. The teeth were removed, sectioned, and examined histologically by two examiners. The results of the histological evaluation of external resorption indicated that there were no statistically significant differences in resorption indices between the teeth obturated with gutta percha or with calcium hydroxide (P>0.05). Replacement resorption was the primary cause of root destruction and only a few histological sections exhibited evidence of inflammatory r

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00149.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

summaryThe purpose of this study was to evaluate the relationship of the quaality of the coronal restoration and of the rot canal obturation on the radiographic periapical status of endodontically treated teeth. Full‐mouth radiographs from randomly selected new patient folders at Temple University Dental School were examined. The first 1010 endodontically treated teeth restored with a permanent rstoration were evaluated independtly by two examiners. Post and core type restorations were excluded. According to a predetermined radiographic standard set of criteria, the technical quality of the root filling of each tooth was scored as either good (GE) or poor (PE), and the quality of the coronal restoration similarly good (GR) or poor (PR). The apical one‐third of the root and surrounding structures were then evaluated radigraphically and the periradicular status categorized as (a) absence of periradicular inflammation (API) or (b) presence of periradicular inflammation (PPI). The rate of API for all endodontically treated teeth was 61.07%, GR resulted in significantly more API cases than GE, 80%, versus 75.7%. PR resulted in significantly more PPI cases than PE, 30.2% versus 48.6%. The combination of GR and GE had the highest API rate of 91.4%, significantly higher than PR and PE with a API rate of 18

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00150.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe distribution of dermatan sulphate and chondroitin sulphate in human dental pulps has been assessed using monoclonal antibodies and immunoperoxidase localization techniques. The pulpal tissues were reacted with specific antibodies following pretreatment of the sections with chondroitinase ACII or chondroitinase ABC. Both the 4‐ and 6‐sulphated isomers of chondroitin sulphate were detected in the tissues studied. Very little derrmatan sulphate could be detected. These glycosaminoglycans appeared throughout the pulpal connective tissues with a particularly strong localization to the region adjacent to the odontoblastic and predentine layers. Such distribution strongly implicates chondroitin sulphate in the mineralization process of human dent

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00151.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryRadiovisiography is a digital intraoral radiographic imaging system requiring a substantial reduction of radiation dosage to the patient over film. For Radiovisiography to replace film, it must be shown to be as efficacious. In this study, a technique of obtaining Radiovisiography and D‐speed film images from the same X‐ ray beam was developed with the use of rare‐earth filters. The quality of the resultant radiovisiographic images was verifiedin vitrowith pure radiovisiographic images of teeth in a dried mandible with soft tissue simulation. Two examiners compared Radiovisiography with D‐speed film for 20 root length estimations using the samein‐vitromodel. A clinical study was then carried out on mandibular molars of patients undergoing endodontic treatment, where 35 root lengths were obtained. The results of bothin vitroand clinical studies showed no statistical differences in the estimated root lengths using the two imaging systems. The measuring grid available in the Radiovisiography unit produced similarly accurate results. Furthermore, the clinical study demonstrated the effective use of Radiovisiography during root canal treatment, with insta

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00152.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThis study compared the linear leakage patterns shown by 5% aqueous solution of methylene blue (MB) and India ink (II).One‐hundred and twenty‐five roots with single canals from extracted human teeth were used. The canals were cleaned and shaped using the step‐back technique under copious irrigation. Three groups were arranged to receive root fillings of gutta‐percha and one of three proprietary sealers using standard lateral condensation techniques: Sealapex (40 roots), Tubli‐Seal (40 roots) and Ketac‐Endo (20 roots). The remaining roots were used as controls: positive with gutta‐percha and no sealer and negative with the apices sealed with nail varnish. The roots were randomly selected for 7‐day immersion in either MB or II, then sectioned longitudinally; dye penetration was assessed using a Wild Leitz stereomicroscope.In all groups MB showed more penetration than II. The results were statistically significant at theP= 0.01 level, with the exception of the positive control groups. Negative controls showed no penetration.It is concluded that MB, which has a low molecular weight penetrated more deeply along root canal fillings than II, which has a larg

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00153.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe aim of thisin vitrostudy was to assess the sealability of a recently introduced thermoplasticized gutta‐percha technique (Trifecta, Hygenic Corp., OH, USA) in the presence or absence of a smear layer. A total of 100 teeth with single straight root canals were included in the study. The teeth were decoronated and the canals prepared with a modified double‐flared technique under constant irrigation with 2.5% sodium hypochlorite solution. The apical matrix was prepared to size 40 and apical patency subsequently confirmed with a size 10 file. Four teeth were discarded for technical reasons and the remaining 96 allocated randomly into two groups of 44 teeth and a group of eight teeth which acted as controls. Canals in group 1 were obturated randomly with either cold lateral condensation of gutta‐percha or with the Trifecta technique. Canals in Group 2 were rinsed with 17% REDTA to remove the smear layer and then obturated with lateral condensation or the Trifecta technique. All teeth were suspended in India ink for 9 days, demineralized, and rendered transparent prior to the assessment of apical linear dye penetration. Apical extrusion of sealer and gutta‐percha occurred commonly but there was no significant difference between the four obturation groups. However, overall, there was significantly more extrusion of sealer with the Trifecta technique compared with lateral condensation (P<0.05). The majority of canals (79 out of 88) had no evidence of apical leakage and there was no significant difference between the groups. The prevalence of sealer and gutta‐percha penetration into the dentinal tubules was significantly different between the four obturation techniques (P<0.01) and significantly more common in the absence of the smear layer (P<0.001). Under the conditions of this study, the Trifecta

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00154.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryTwenty patients with large endodontic lesions, which failed to respond to conventional endodontic therapy, were selected for this study. The lesions had a radiographic diameter of at least 10 mm, were removed by periradicular surgery, before retrofilling the apices with either super EBA or dessicated zinc oxide‐eugenol. In 10 test sites large e‐PTFE membranes (Gortex) were placed to cover the lesions, while at the control sites the lesions were not covered before resuturing. Radiographic analysis of the lesions at 3, 6, 9 and 12 months revealed that lesions covered with the membranes healed quicker than the control lesions, and that the quality and quantity of the regenerted bone was superior when membranes were used. Results of the study indicate that guided tissue regeneration (GTR) principles can be effectively applied to the healing of large periapical lesions, especially in through‐and‐through

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00155.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe purpose of this pilot study was to investigate some of the clinical variables in ultrasonic endodontics. Forty extracted human teeth with a single, straight root 21–25 mm in length were prepared using combinations of the following variables: hand or ultrasonic instrumentation; apical seat prepared to file sizes 35, 40, 45 or 50; lml of water, 4% sodium hypochlorite or EDTAC as irrigant between each instrument size; three brands of ultrasound generator and inserts; a ‘low’, ‘medium’ or ‘high’ effective power output; a tuned or untuned circuit; post‐instrumentation ultrasonic irrigation with either 4% sodium hypochlorite, EDTAC, or the two used in sequence. The specimens were viewed in a scanning electron microscope and scored for the presence or absence of a smear layer at levels<1 mm, 5 mm and 10 mm from the apical seat. The most effective combination, as tested, was hand instrumentation to file size 40 with lml EDTAC irrigation between each instrument size, supplemented by intermittent flush irrigation with EDTAC with ultrasound then 4% sodium hypochlorite with ultrasound. This technique left a minimum smear layer restricted to the apical seat. Other combinations of instrumentation and irrigation were not consistent in thei

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00156.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThirty single‐rooted teeth were prepared to receive cast posts. After cementation of the post the teeth were divided into three groups. Group I did not receive any treatment, whereas the posts in groups II and III were treated with an ultrasonic device, for 2 min and 5 min, respectively. The force required for post removal was determined using a universal test machine. No statistical differences (P>0.05) were found between the groups where ultrasound had been used.Significantly reduced forces were necessary to remove the posts from group II and III, compared with group I which did not receive ultrasonic treatment (P<0.05

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00157.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY