摘要:

Summary.The purpose of the present study was to assess the effect of compactor design, alterations in rotational speed and modification to the basic technique of thermomechanical compaction on the quality of the apical seal produced by gutta‐percha and sealer cement. The integrity of the apical seal achieved using two different configurations of compactor, rotational speeds of 8000 and 16,000 rev/ minute and a hybrid technique which combined thermomechanical compaction with lateral condensation were compared with conventional lateral condensation. The same brand of gutta‐percha and type of sealer were used throughout the investigation.A cleared tooth technique that allowed the three‐dimensional assessment of Indian ink leakage was employed. Instrument fracture, a problem experienced in some other investigations, did not occur with either design of compactor used. Apical dye leakage was found to be a relatively frequent occurrence with each variation in obturation technique studied, including that of lateral condensation of cold gutta‐percha and sealer. The results showed no significant difference in the mean degree of leakage for each of the groups or in the proportion of specimens that showed leakage (P>0.1).The advantages of the hybrid method of root canal obturation were di

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00918.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.The heat generated on the external root surface of human premolar teeth during post space preparation was measuredin vitro. The rise in temperature was recorded at a point 6 mm from the apex of the tooth using a thermocouple attached to a chart recorder. The temperature rise was greatest when the removal of gutta‐percha was combined with post channel preparation. Temperature rises of up to 31°C were recorded. Instruments that only removed gutta‐percha did not generate the same amount of heat.The results from this study suggest that the use of engine‐driven drills to prepare post channels in teeth may generate temperature rises that may cause periradicular tissue damage, and caution should be exercised during the

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00919.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.The effectiveness of irrigant replacement in fine canals was compared using three sizes of irrigating needle and an ultrasonic method. The result showed that irrigant replacement became progressively less effective towards the apex regardless of the method of irrigation or needle size. With conventional methods, irrigation performance varied with the size of needle and volume of irrigant. With the ultrasonic method results depended on irrigation time, but was independent of irrigant flow rate through the handpiece, the size of the canal or the file size.

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00920.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.A clinical study using upper central incisors was carried out to evaluate the incidence of postoperative pain after root canal preparation by the double‐flared technique. Sixty teeth with necrotic pulps from 48 patients whose ages ranged from 12 to 65 years were prepared and filled in either one or two appointments. No difference was observed in the incidence of postoperative pain between the two group

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00921.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.Two groups of teeth, one of which contained teeth of known age, were examined by scanning electron microscopy to ascertain the presence of a potential pathway for leakage at the root ends of apicected teeth. At a point approximately 3 mm from the apex, a level chosen as being typical for apicectomy, and half‐way between the root canal and the dentine‐cementum junction, there were found to be, on average, 27,000 tubules per mm2. Older teeth also displayed large numbers of tubules. Close to the dentine‐cementum junction, an area which may communicate with the root canal even in the presence of a retrograde root filling, an average of 13,000 tubules per mm2were

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00922.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.A severe case of dens invaginatus is described on an upper central incisor that was associated with a discharging sinus tract. The outer pulp chamber contained vital tissue while the inner one contained necrotic material. Root canal treatment was carried out with long‐term calcium hydroxide dressings to induce apical closure. The canal system was subsequently filled and the tooth followed up for 4 year

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00923.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.This report presents a case of undiag‐nosed, cracked, bilateral, maxillary molars. Both teeth were non‐carious and unrestored. Failure to diagnose the initial cracks resulted in further splitting, and finally complete vertical fractures. The problem of diagnosis is highlighted and the treatment of the cracked tooth to prevent its fracture is discus

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00924.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

Summary.A case is reported in which apical penetration by a root canal irritant occurred. The clinical manifestations are described and the case management discussed.

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00925.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00926.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1989.tb00927.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY