摘要:

Summary.The periapical tissue response to glass ionomer cement retrograde root fillings was investigated both in the presence and in the absence of fillings in the root canals of eight upper incisor teeth of four monkeys. The pulps of the teeth were extirpated and one canal in each pair was filled with laterally condensed gutta‐percha immediately after canal preparation. The other canal was prepared but left open to oral contamination. Apicectomies were performed on both teeth in each pair 1 week later, and glass ionomer cement retrograde root fillings were placed. After 5 months, the teeth and surrounding tissues were removed and prepared for histological examination.All four of the teeth without root canal fillings showed severe periapical inflammation, and bacteria were present in the interface between the dentine and the retrograde root filling. The teeth with root canal fillings showed or no periapical inflammation.This study showed that adhesive retrograde root fillings were successful when the root canal was completely filled, but in the absence of a guttapercha canal filling they failed to provide a sea

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00854.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.The effect of post canal preparation on the apical seal of endodonticaily treated teeth was studiedin vitro.Single‐rooted teeth with mature apices were prepared chemomechinically and obturated with gutta‐percha and sealer using one of four techniques: cold lateral condensation, thermo‐mechanical compaction, thermomechanical compaction as an adjunct to lateral condensation (hybrid technique), or lateral condensation using an electrically heated spreader, the Endotec. Forty‐eight hours after obturation each group of 15 teeth was prepared to accept a post crown. Five teeth in each group were left unprepared as controls. The extent of apical leakage was then determined using a dye, Indian ink, and a clearing technique that rendered the teeth transparent. Linear measurement of the dye penetration was recorded. The results showed that, for each method of obturation, there were no statistically significant differences between the teeth prepared for a post and the unprepared controls. There were no significant differences in leakage between the different groups that had been prepared for a post, or between the control

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00855.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.Anin vitroendodontic leakage model was used to compare the sealing ability of conventional retrograde amalgam fillings with a new retrograde filling technique by measuring dye leakage quantitatively.The new technique consisted of retrograde preparation of the root canal using the Endocursor1, an endodontic handpiece. The canal was then filled with sealer and injection‐moulded gutta‐percha, using either the Hygenic Ultrafil2system or the Unitek Obtura3method. In both cases the guttapercha was vertically condensed and subsequently cold‐burnished.The two experimental groups and the amalgam group each consisted of 20 extracted human canine teeth and lower premolars. The results were analysed statistically by ANOVA and a Student‐Newman‐Keuls multiple comparison test. After 1 week at 37°C, very little leakage was observed in the amalgam and gutta‐percha groups. After a second week, during which leakage was enhanced by gas pressure, leakage in the amalgam group was significantly greater than that in the gutta‐percha groups (P0.01). There were no significant differences between the two experimental gutta‐percha groups. It is concluded that the new retrograde filling technique causes less leakage than the conventional amalgam retrograde filling technique in

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00856.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.A dye leakage study was performedin vitroto compare the extent of leakage into root canals obturated with gutta‐percha following immediate versus delayed immersion in Indian ink. Sixty extracted human teeth with single canals were instrumented and obturated with gutta‐percha and sealer. Each group of 20 teeth was then immersed in the ink either immediately after obturation or after a delay of 1 or 7 days. After 7 days in Indian ink, the teeth were rendered transparent by clearing, and the linear extent of ink penetration was measured with a stereomicroscope. Complete leakage was observed in the two positive control teeth, and no leakage was evident in the two negative controls. Statistical analysis of the results indicated that there was no significant difference in leakage between the three experimental gro

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00857.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.A case is presented in which rapid and extensive bone loss occurred around a maxillary molar with periapical infection byBacleroides gingivalis (Ptrphyrmaonas gingivalis).The lesion failed to respond to conventional endodontic therapy. An adjacent vital molar was extracted and an unfavourable periodonta) condition occurred despite microbiological investigation and surgery.

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00858.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.Temperature elevations of 10°C above body temperature, of duration 1 minute, may be sufficient to cause bone tissue injury. Temperature rises on the root surface in excess of 10°C have been shown in studiesin vitroof thermoplasticized gutta‐percha root filling techniques. To determine whether resultsin vitroat room temperature could be extrapolated to conditionsin vivo, temperature elevations were recorded at the mid‐point on the root surface of the canine tooth in the ferret during thermomechanical compaction of gutta‐percha. The time taken for the temperature to return to normal was also measured. There was no statistically significant difference between temperature elevations recordedin vitroand those measuredin vivo, A linear extrapolation may therefore be made from results recorded at room temperature.Temperature elevations dissipated more rapidly invivothanin vitro; this may be due to the cooling effect of the microvasculature of the periodontal m

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00859.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

Summary.An in bim investigation is described and a histologiesl evaluation made of the effect of canal obturation by thermomechanical compaction of gutta‐percha and sealer on the cementum on the lateral surface of the root and adjacent periodontal membrane and alveolar bone of the ferret canine after rime intervals of 24 hours, 20 days and 40 days. These tissue reactions were compared with those in the roots of control teeth filled by lateral condensation of cold gutta‐percha and sealer. latrogenk‐damage was apparent in a minority of the experimental specimens 20 and 40 days after obtur

ISSN:0143-2885    

DOI:10.1111/j.1365-2591.1990.tb00860.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.tb00861.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.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY