Thermal behavior and viscoelastic properties of gutta-percha used for back-filling the root canal.
Differential scanning calorimetry
Gutta-percha
Root canal obturation
Viscoelastic substances
Journal
Journal of dental sciences
ISSN: 2213-8862
Titre abrégé: J Dent Sci
Pays: Netherlands
ID NLM: 101293181
Informations de publication
Date de publication:
Mar 2020
Mar 2020
Historique:
received:
16
09
2019
revised:
16
10
2019
entrez:
8
4
2020
pubmed:
8
4
2020
medline:
8
4
2020
Statut:
ppublish
Résumé
In clinical operations, qualitative differences in the texture and operational feeling of the regular type and soft type back-filled gutta-percha are readily discernible. This study aimed to investigate and compare the thermal behavior and physical properties of the two gutta-percha materials. The chemical compositions of regular and soft type Gutta-Percha Obturator® pellets were examined via energy dispersive X-ray spectroscopy. The thermal behaviors of the pellets during heating and cooling were evaluated using a differential scanning calorimeter. Finally, the viscoelastic properties of the two materials during cooling were assessed using a modular compact rheometer. The soft type gutta-percha contained a greater atomic percentage of zinc than the regular type material. In addition, the soft type gutta-percha exhibited exothermic peaks during cooling, whereas the regular type gutta-percha did not. The two materials exhibited different viscoelastic behaviors under cooling. In particular, the rate of change of the loss factor for the soft type gutta-percha was more than that of the regular type gutta-percha at temperature lower than 80°C. The soft type gutta-percha underwent significant crystallization during cooling, and therefore exhibited pronounced volume shrinkage. Furthermore, the soft type gutta-percha underwent a greater rate of change in viscoelasticity under cooling than the regular type gutta-percha, and exhibited poorer physical stability. Consequently, in the back-packing procedure, soft type gutta-percha must be compacted more often over time than regular type gutta-percha to ensure the same quality of root canal obturation.
Sections du résumé
BACKGROUND/PURPOSE
OBJECTIVE
In clinical operations, qualitative differences in the texture and operational feeling of the regular type and soft type back-filled gutta-percha are readily discernible. This study aimed to investigate and compare the thermal behavior and physical properties of the two gutta-percha materials.
MATERIALS AND METHODS
METHODS
The chemical compositions of regular and soft type Gutta-Percha Obturator® pellets were examined via energy dispersive X-ray spectroscopy. The thermal behaviors of the pellets during heating and cooling were evaluated using a differential scanning calorimeter. Finally, the viscoelastic properties of the two materials during cooling were assessed using a modular compact rheometer.
RESULTS
RESULTS
The soft type gutta-percha contained a greater atomic percentage of zinc than the regular type material. In addition, the soft type gutta-percha exhibited exothermic peaks during cooling, whereas the regular type gutta-percha did not. The two materials exhibited different viscoelastic behaviors under cooling. In particular, the rate of change of the loss factor for the soft type gutta-percha was more than that of the regular type gutta-percha at temperature lower than 80°C.
CONCLUSION
CONCLUSIONS
The soft type gutta-percha underwent significant crystallization during cooling, and therefore exhibited pronounced volume shrinkage. Furthermore, the soft type gutta-percha underwent a greater rate of change in viscoelasticity under cooling than the regular type gutta-percha, and exhibited poorer physical stability. Consequently, in the back-packing procedure, soft type gutta-percha must be compacted more often over time than regular type gutta-percha to ensure the same quality of root canal obturation.
Identifiants
pubmed: 32256997
doi: 10.1016/j.jds.2019.10.002
pii: S1991-7902(19)30865-7
pmc: PMC7109509
doi:
Types de publication
Journal Article
Langues
eng
Pagination
28-33Informations de copyright
© 2019 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V.
Déclaration de conflit d'intérêts
The authors deny any conflict of interest related to this study.
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