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Shrinkage of backfill gutta-percha upon cooling


Lottanti, Silvio; Tauböck, Tobias T; Zehnder, Matthias (2014). Shrinkage of backfill gutta-percha upon cooling. Journal of Endodontics, 40(5):721-724.

Abstract

INTRODUCTION The temperature and related shrinking kinetics of gutta-percha injected from heat guns are not known; therefore, we investigated them in this study. METHODS The temperatures of 3 different backfill gutta-percha brands extruded from 3 commercially available heat guns set to 200°C were studied. To validate the results, temperature development of 1 gutta-percha brand injected from a heat gun during a simulated backfilling procedure was assessed in single-rooted human teeth containing thermocouples in a water bath of 37°C. These values were compared with the counterparts obtained in a tabletop testing device for shrinkage at an ambient temperature of 37°C. Using this device, linear shrinkage upon cooling was assessed for all 3 gutta-percha brands under investigation. Results were compared by parametric statistics (alpha = .05). RESULTS The temperatures of extruded gutta-percha differed significantly (P < .05) between heat guns and gutta-percha brands. Mean temperatures ranging between 57.6° ± 4.5°C and 103.9° ± 7.8°C could be observed with different combinations. The temperature of extruded gutta-percha in tabletop experiments equaled that observed in the root canals. However, the cooling of gutta-percha was (P < .05) faster in the tabletop measuring device compared with the root canal environment. Within the controlled temperature drop from 75°C to 37°C, the total shrinkage differed significantly (P < .05) between the 3 gutta-percha brands under investigation and ranged between 0.96% ± 0.20% and 2.31% ± 0.26% after 10 minutes (P < .05). Shrinking kinetics showed different patterns between the gutta-percha brands. CONCLUSIONS Gutta-percha designed for thermoplastic application shrinks quickly and extensively upon cooling.

Abstract

INTRODUCTION The temperature and related shrinking kinetics of gutta-percha injected from heat guns are not known; therefore, we investigated them in this study. METHODS The temperatures of 3 different backfill gutta-percha brands extruded from 3 commercially available heat guns set to 200°C were studied. To validate the results, temperature development of 1 gutta-percha brand injected from a heat gun during a simulated backfilling procedure was assessed in single-rooted human teeth containing thermocouples in a water bath of 37°C. These values were compared with the counterparts obtained in a tabletop testing device for shrinkage at an ambient temperature of 37°C. Using this device, linear shrinkage upon cooling was assessed for all 3 gutta-percha brands under investigation. Results were compared by parametric statistics (alpha = .05). RESULTS The temperatures of extruded gutta-percha differed significantly (P < .05) between heat guns and gutta-percha brands. Mean temperatures ranging between 57.6° ± 4.5°C and 103.9° ± 7.8°C could be observed with different combinations. The temperature of extruded gutta-percha in tabletop experiments equaled that observed in the root canals. However, the cooling of gutta-percha was (P < .05) faster in the tabletop measuring device compared with the root canal environment. Within the controlled temperature drop from 75°C to 37°C, the total shrinkage differed significantly (P < .05) between the 3 gutta-percha brands under investigation and ranged between 0.96% ± 0.20% and 2.31% ± 0.26% after 10 minutes (P < .05). Shrinking kinetics showed different patterns between the gutta-percha brands. CONCLUSIONS Gutta-percha designed for thermoplastic application shrinks quickly and extensively upon cooling.

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4 citations in Web of Science®
4 citations in Scopus®
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Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Center for Dental Medicine > Clinic for Preventive Dentistry, Periodontology and Cariology
Dewey Decimal Classification:610 Medicine & health
Language:English
Date:May 2014
Deposited On:20 Nov 2014 10:15
Last Modified:18 May 2016 07:48
Publisher:Elsevier
ISSN:0099-2399
Publisher DOI:https://doi.org/10.1016/j.joen.2013.09.043
PubMed ID:24767571

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