Heat generation during removal of an abutment screw fragment from dental implants.
J Prosthet Dent
; 119(4): 620-625, 2018 Apr.
Article
em En
| MEDLINE
| ID: mdl-28967404
ABSTRACT
STATEMENT OF PROBLEM:
Little information is available on the effect of drilling speed on surrounding bone during the removal of an abutment screw fragment.PURPOSE:
The purpose of this in vitro study was to compare, in vitro, the peak temperature increase during the removal of fractured abutment screws from implants placed in a porcine mandible, using drilling speeds of 600 or 2000 rpm. MATERIAL ANDMETHODS:
Twenty 4.3×13-mm dental implants were placed in 10 dissected porcine mandibles 2 implants per mandible, 1 on each side. Localized defects were created in 20 surface-treated abutment screws, which were then tightened into each implant until a reproducible fracture occurred in each screw. The fractured screws were removed with a handpiece removal kit and irrigated with room-temperature water at either 600 or 2000 rpm. The temperature rise at the implant surface was measured at 3 levels with 3 type-K thermocouples. Repeated measure ANOVA was performed with the Tukey-Kramer post hoc test for mean pair-wise comparisons (α=.05 for all tests).RESULTS:
Mean peak temperatures were significantly higher at 2000 rpm than at 600 rpm in the mid-body (P<.001) and crestal (P=.003) regions but not in the apical (P=.225) implant locations. No significant differences in mean peak temperatures were found among the 3 locations using 600 rpm (P=.179). In the 2000-rpm group, mean peak temperature in the mid-body area was consistently higher than that in the apical (P<.001) area, and more instances of temperature rise above 56°C and 60°C were observed. In 1 implant from this group, the estimated peak temperature exceeded the bone damage threshold value (50°C for 30 seconds).CONCLUSIONS:
A drilling speed of 2000 rpm during the removal of abutment screw fragments caused overheating of the outer surface of the implant which may damage the surrounding bone; a speed of 600 rpm appears to be safe.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Temperatura
/
Parafusos Ósseos
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Equipamentos Odontológicos de Alta Rotação
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Remoção de Dispositivo
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Transferência de Energia
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article