Cargando…

Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants

PURPOSE: The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS: Forty screw-retained single crowns were connected to external and internal hex implants....

Descripción completa

Detalles Bibliográficos
Autores principales: Mohammed, Hnd Hadi, Lee, Jin-Han, Bae, Ji-Myung, Cho, Hye-Won
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Korean Academy of Prosthodontics 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4769891/
https://www.ncbi.nlm.nih.gov/pubmed/26949489
http://dx.doi.org/10.4047/jap.2016.8.1.62
_version_ 1782418173571629056
author Mohammed, Hnd Hadi
Lee, Jin-Han
Bae, Ji-Myung
Cho, Hye-Won
author_facet Mohammed, Hnd Hadi
Lee, Jin-Han
Bae, Ji-Myung
Cho, Hye-Won
author_sort Mohammed, Hnd Hadi
collection PubMed
description PURPOSE: The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS: Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. RESULTS: The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). CONCLUSION: Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading.
format Online
Article
Text
id pubmed-4769891
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher The Korean Academy of Prosthodontics
record_format MEDLINE/PubMed
spelling pubmed-47698912016-03-06 Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants Mohammed, Hnd Hadi Lee, Jin-Han Bae, Ji-Myung Cho, Hye-Won J Adv Prosthodont Original Article PURPOSE: The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. MATERIALS AND METHODS: Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. RESULTS: The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). CONCLUSION: Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading. The Korean Academy of Prosthodontics 2016-02 2016-02-23 /pmc/articles/PMC4769891/ /pubmed/26949489 http://dx.doi.org/10.4047/jap.2016.8.1.62 Text en © 2016 The Korean Academy of Prosthodontics http://creativecommons.org/licenses/by-nc/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Original Article
Mohammed, Hnd Hadi
Lee, Jin-Han
Bae, Ji-Myung
Cho, Hye-Won
Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
title Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
title_full Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
title_fullStr Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
title_full_unstemmed Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
title_short Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
title_sort effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4769891/
https://www.ncbi.nlm.nih.gov/pubmed/26949489
http://dx.doi.org/10.4047/jap.2016.8.1.62
work_keys_str_mv AT mohammedhndhadi effectofabutmentscrewlengthandcyclicloadingonremovaltorqueinexternalandinternalheximplants
AT leejinhan effectofabutmentscrewlengthandcyclicloadingonremovaltorqueinexternalandinternalheximplants
AT baejimyung effectofabutmentscrewlengthandcyclicloadingonremovaltorqueinexternalandinternalheximplants
AT chohyewon effectofabutmentscrewlengthandcyclicloadingonremovaltorqueinexternalandinternalheximplants