摘要:

Summary.A series of deep cavities with and without traumatic pulpal exposures were prepared in the maxillary molars of albino rats. They were left untreasted for various time intervals before killing.Demineralized sections were prepared in a mesiodistral plane and stained to demonstrate the presence that were grossly contaminated, bacteria were detected in the majority of sections. In the roor canaks and periapical tissues, bacteria were detected in only a minority of sections.It is considered that serial sections stained to demonstrate bacteria are necessary for the detection of bacteria that the present in only small numbers in the tissue. The demonstration of small numbers of micro‐organisms in specific zones of the pulp remains problematic. Failure to detect stained bacteria in histological sections is not absolute proof of their absenc

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00796.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.The adhesive properties of eight root canal sealers, applied as a thin layer between a dentine and a gutta‐percha surface, were investigated. Tensile bond strengths ranged from 0.02 MPa (Sealapex) to 2.38 MPa (AH26). Inspection of fractured surfaces indicated failure of adhesion to dentine (Tubli‐Seal) and to gutta‐percha (AH26, Diaket) as well as failure of cohesion (CRCS, Kloroperka N‐Ø, ProcoSol, rosin chloroform, Sealapex). Pretreatment of the dentine surface with EDTA caused a significant increase in bond strength for ProcoSol, rosin chloroform, Sealapex, and Tu

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00797.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.This study was carried out to investigate the presence and types of bacteria invading the deep layers (0.5–2.0 mm from the surface of the root canal wall) of infected dentine of human root canals by sampling with an anaerobic glove box system the split surfaces of eight freshly extracted teeth. More bacteria were recovered after incubation in an anaerobic glove box than after aerobic incubation in air with 30 per cent CO2. Out of 256predominant bacteria isolated, 205 isolates (80 per cent)were bligate anaerobes. These findings suggest that the environment of deep layers of endodontic dentmal lesions is anaerobic and favours the growth of anaerobes. Among the obligate anaerobic isolates, strains belonging toLacto‐bacillus(30 per cent) andStreptococcus(13 per cent) were predominant, followed byPropionitacterium(9 per cent). No strains of obligate anaerobic Gram‐negative rods were isolated. The tnicroflora of deep layers of infected root dentine is somewhat similar to that of the deep layers of carious lesions in coronal de

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00798.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.The leakage associated with restorative materials placed within the pulp chamber of maxiliary and mandibular molars was studiedin vitro.The root canals and pulp chambers of 69 extracted teeth were prepared chemomechanically and scaled with gutta‐percha and Tubliseal using cold lateral condensation. The teeth were divided into five groups. Gutta‐percha was removed from the pulp chambers of three of the groups of 15 teeth and filled with one of three materials, a glass ionomer cement, a cermet cement or an amalgam. The guttapercha was removed from the pulp chamber in the fourth group of nine teeth, which were left unfilled. The gutta‐percha in the pulp chambers of the fifth group of teeth was left intact.The teeth were suspended in Indian ink, thermocycied for 24 hours and stored for a further 48 hours at 37°C. They were then demineralized and cleared and the degree of coronal leakage was assessed. Those teeth with no filling in the pulp chamber showed extensive leakage. The gutta‐percha‐filled group demonstrated greater leakage than did the groups in which other restorative materials had been employed (P0.05). It is recommended that the pulp chamber of molars should be restored with a filling material following root canal

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00799.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.The root canal anatomy of 149 mandibular second molars was studied using a technique in which the pulp was removed, the canai space filled with black ink and the roots demineralized and made transparent. Of the 149 teeth, 22 per cent had single roots, 76 per cent had two roots and 2 per cent had three roots. In the single‐rooted teeth, three canals were most common, while in the mesial root of the two‐rooted teeth, two canals that joined near the apex and one canai in the distal root were most frequent. Round canals were most common in two‐rooted teeth and C‐shaped canals in single‐rooted teeth. Transverse anastomoses were found in 33 per cent of roots, most commonly in the middle third of the root. Lateral canals were found in 72 per cent of roots, most commonly in the apical third of the root. The apical foramen was positioned at the apex in only 33 per cent of roots, and apical deltas were found in 35 per cent.The patient's age and race affected canal shape, with more round canals present in patients over 35 years of age, and more C‐shaped canals in Asians. The sex of the patient and the side of the mouth affected the presence of apical deltas, with more being found in males and on the left side. Single‐rooted teeth had more complex root canal systems than two‐rooted teeth, with more lateral canals, transverse anastomoses, apical deltas and

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00800.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.The root canal anatomy of 19 mandibular second molars with C‐shaped canals was investigated by rendering the roots transparent and allowing the canal system to be observed by black ink infiltration. The presence of three root canals was most frequent, and lateral canals were found in all roots. Transverse anastomoses were found in 15 of the 19 roots. The apicaf foramen was most commonly situated away from the apex, and apical deltas were found in 16 of the 19 roots. The C‐shaped canals were found more frequently in Asians than in other racial groups(P<0.02).The formation of C‐shaped roots and their racial predilection is discussed. A case report of the root canal treatment of a C‐shaped canal is included and suggestions are made concerning suitable procedures for use in root canal treatment of these complex canal

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00801.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.The histological response of periapical tissues to root canal fillings with Sealapex, pure calcium hydroxide and gutta‐percha points was studied in dogs' teeth. After putpal extirpation the root canals were enlarged, irrigated and dried. Teeth in the first group were filled with gutta‐percha points alone, those in the second group were filled with pure calcium hydroxide and gutta‐percha, and those in the third group were filled with Sealapex and gutta‐percha. The animals were killed after 7, 30 and 90 days and histological sections of each specimen were prepared. It was concluded that hard tissue formation was more pronounced after root filling with Sealapex than with calcium hydroxide or gutta‐perc

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00802.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00803.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Book reviewed in this article:Endodontic Thempy4th edn, F. S. WeineEndodontic Radiography: Principles and Cliical TechniquesS. A. Cohn

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00804.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00805.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY