摘要:

SummaryDetermination of leakage using a fluid transport model allows measurement of leakage in a longitudinal manner. Leakage of four sealers at three different thick‐ nesses in 225 bovine root sections, after storage in water for 1 year, was measured again using the same method‐ ology. The change in seal over time for each sealer was observed. The results after the second measurement showed that every sealer produced the best seal when the sealer layer was the thinnest. AH26, Ketac‐Endo and Tubli‐Seal showed a reduction in leakage over time and gave significantly less leakage than Sealapex (P<0.005). Sealapex showed sigdicantly more leakage after storing in water for 1 year (P<0.005). Therefore, the long‐lasting seal of sealer may, among other influencing factors, depend on the layer thickness and the solubility of the

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00297.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe purpose of this study was to observe the quality of seal of the glass ionomer cement, Ketac‐Endo, after treatment of the root canal wall. The root canals of 140 extracted human teeth were prepared biomechanically. The root canals were treated with either EDTA or received an intracanal dressing of calcium hydroxide or camphorated paramonochlorphenol. The root canals were filled by the lateral condensation technique with gutta‐percha points and the sealer Ketac‐Endo, or zinc oxide‐eugenol cement or Sealapex. The teeth were placed into a 2% methylene blue dye solution inside a flask, which was attached to a vacuum pump. Leakage was measured linearly. Sealapex exhibited significantly less leakage than Ketac‐Endo or zinc oxide‐eugenol cement (P<0.01). The use of EDTA and intermediary dressings reduced significantly (P<0.01) the leakage observed with the zinc oxide‐eugenol sealer a

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00298.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe sealing ability of amalgam and Gallium Alloy Gallium Filling (GF) root‐end fillings was evaluatedin vitrousing a highly uniform collection of sheep incisor roots. Following ultrasonic canal debridement and orthograde obturation with gutta‐percha and sealer, root‐end cavities were prepared in 100 roots and filled with amalgam (50 teeth) or Gallium Alloy GF (50 teeth). Twenty‐five teeth from each group were subjected to immediate dye leakage assessment under vacuum conditions with methylene blue dye (2%), pH 7. Linear dye penetration was measured following longitudinal splitting. The other 25 teeth from each group were incubated in Ringer's solution for 12 weeks before leakage assessment by the same method. Control teeth were included in each component of the study.Mean linear dye penetration was: amalgam—5.17mm at baseline, 2.33mm after 12 week's incubation; Gallium Alloy GF—2.21mm at baseline, 1.41mm after 12 week's incubation. The apical marginal seal of both materials improved significantly following storage in Ringer's solution (P<0.001). Gallium Alloy GF provided a better apical seal than amalgam, both at baseline and following storage (P<0.001). Subjective evaluation of the general handling characteristics of Gallium Alloy GF revealed that it was a more difficult material to manipulate than amalgam, largely because of its wetting ability and consequent adhesion to dental

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00299.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThe radiographic quality of root‐canal fillings, the prevalence of periapical findings and their associations with gender and age and were investigated in 133 dentate old people living at home (45 males and 88 females, aged 76, 81, and 86 years and who had endodontically treated teeth or periapical lesions.Sixteen per cent of the endodontically treated teeth (n= 507) exhibited periapical lesions, compared with 4% for the teeth not endodontically treated (P<0.0001) (χ2test). Lesions were least prevalent in association with radiographically adequate root canal fillings (10%), and most prevalent in teeth with root canal post perforation (100%). Overfilled root canals and multi‐rooted teeth with one or more unfilled roots also showed a high percentage of lesions (19% and 22%, respectively). Men had more periapical lesions than women in endodontically treated teeth (P<0.0001, Mann‐WhitneyU‐test), a finding contrary to previous studies in younger subjects. There were no other statistically significant differences between the sexes or age groups, although the percentage of root‐filled teeth increase

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00300.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryA phantom head model was modified to simulate as closely as possible the limited access encountered during periapical surgery on maxillary anterior teeth. Extracted human maxillary anterior and mandibular canine teeth were placed in this model in a standardized position for root resection, retrograde cavity preparation and filling with amalgam. Three different designs of retrograde cavities were evaluated: the conventional class 1 cavity, the slot cavity and a previously unreported approach, the funnel cavity.Upon completion of the retrograde filling, the teeth were removed from the model and subjected to microleakage tests by placing radiolabelled lipopolysaccharide in a reservoir created coronal to the retrograde fillings. Leakage was quantified by measurement of radioactivity in scintillation counter.It was found that the retrograde fillings in the funnel cavity leaked significantly less than those in the other two cavity designs. There was no statistically significant difference in leakage between the conventional class 1 and the slot cavities up to the thirtieth day 30.

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00301.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryA Neodyminium‐yttrium aluminium garnet (Nd–YAG) pulsed laser was usedin vitroto determine whether various laser energy levels from 0.75 W to 1.7 W at 15 pulses s−1(pps) were able to (i) remove debris from the walls of prepared root canals (ii) remove pulpal tissue from unprepared canals and (iii) create a fused apical plug from dentine chips, hydroxyapatite (HAP) or low‐fusing dental porcelain. Single‐rooted teeth were sectioned at the amelocemental junction and the crowns discarded. The root canals of 50 teeth were prepared chemomechanically and allocated to four groups of 10 teeth for laser treatment. One group was left unlased as a control. After lasing, the teeth were split longitudinally, stained and examined for residual debris. Results showed that there was no statistically significant difference between the groups (P<0.05). A further 20 teeth were not prepared and lased in the coronal one‐third of the root canal at different energy levels; five teeth were not lased. The teeth were split and examined as previously. The results showed that lasing cleaned the coronal part of the root canal almost completely of pulpal tissue. In the final part of the study laser energy was applied to dentine chips, HAP and low‐fusing procelain in an attempt to produce a fused apical plug. The laser was unable to melt the dentine chips but some hardening of HAP occurred when combined with blue food‐colouring, with or without glycerine, at energy levels of 1.0 W, at 15 pps for 30 s. Superficial hardening of low‐fusing porcelain occurred at 1.0 W, 15 pps for 30 s which increased when 1.5 W was applied

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00302.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY

摘要:

SummaryThis study investigated the weights of irrigant extruded apically through extracted primary molar teeth. The aim was to compare the weight of canal irrigant (isotonic sodium chloride solution) extruded through the root canal using either a syringe fitted with a27‐gauge needle or an endosonic unit. Root canals were divided randomly into five groups of 15 discrete canals. The area of each apical foramen was recorded prior to the use of the irrigant. For each irrigation technique the maximum depth of penetration of the needle tip/file was either 2–3 mm or 6–7 mm from the apical foramen. In four groups the crowns of the teeth were in a mandibular position, in the fifth group the teeth were inverted to simulate maxillary teeth. The results showed that irrigant was extruded using both methods. There was significantly less extrusion of irrigant when the endosonic unit was used (P

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1995.tb00303.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.tb00304.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.tb00305.x

出版商:Blackwell Publishing Ltd    

年代:1995

数据来源: WILEY