Evaluation of several protocols for the application of ultrasound during the removal of cast intraradicular posts cemented with zinc phosphate cement.
Int Endod J
; 42(7): 609-13, 2009 Jul.
Article
em En
| MEDLINE
| ID: mdl-19467051
ABSTRACT
AIM:
To evaluate several protocols for the application of ultrasound during removal of cast posts with varying core configurations cemented with zinc phosphate.METHODOLOGY:
Sixty maxillary canines were distributed into three groups (n = 20) group 1 - core with 5 mm diameter/height and post diameter of 1.3 mm; groups 2 and 3 - core with the same diameter as the post (1.3 mm) and heights of 5 mm and 3 mm, respectively. Posts/cores were cemented using a standard technique with zinc phosphate cement. Each group was divided into two subgroups according to the ultrasonic vibration mode point vibration - ultrasonic vibration applied to the core surface for 5 s, on each face totalling 25 s; alternate vibration - intermittent application of ultrasonic vibration for 10 s to the labial and lingual surfaces, 10 s to the mesial and distal surfaces and 5 s to the incisal surface, totalling 25 s. The specimens were submitted to the tensile test using an Instron machine (1 mm min(-1)) and results were analysed by anova and t-test. The failure type was also analysed.RESULTS:
Statistical analysis showed significant differences between groups relating to the core preparations (P < 0.05). The lowest mean values of traction force were obtained for group 3 (46.1 +/- 7.7 N), followed by group 2 (89.0 +/- 2.7 N) and group 1 (160.4 +/- 7.5 N). Regarding ultrasonic vibration, the lowest mean was observed with alternate vibration (81.1 +/- 10.1 N), which was significantly lower than the point vibration (115.9 +/- 9.5 N) (P < 0.05). Cohesive failure occurred in all cases.CONCLUSION:
A reduction in core diameter/height and intermittent ultrasonic application improved the removal of cast posts cemented with zinc phosphate.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Ultrassom
/
Cimento de Fosfato de Zinco
/
Técnica para Retentor Intrarradicular
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Cimentação
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Descolagem Dentária
Tipo de estudo:
Clinical_trials
Limite:
Humans
Idioma:
En
Revista:
Int Endod J
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Brasil