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Biomechanical Evaluation of Platform Switching: Different Mismatch Sizes, Connection Types, and Implant Protocols
Author(s) -
Pessoa Roberto S.,
Bezerra Fábio J.B.,
Sousa Ravel M.,
Vander Sloten Jos,
Casati Marcio Zaffalon,
Jaecques Siegfried V.N.
Publication year - 2014
Publication title -
journal of periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.036
H-Index - 156
eISSN - 1943-3670
pISSN - 0022-3492
DOI - 10.1902/jop.2014.130633
Subject(s) - connection (principal bundle) , implant , computer science , biomedical engineering , medicine , engineering , structural engineering , surgery
Background: It is not yet well understood to what extent different implant–abutment mismatch sizes and implant–abutment connection types may influence the peri‐implant biomechanical environment of implants in different clinical situations. Methods: Computed tomography–based finite element models comprising a maxillary central incisor socket and 4.5 × 13 mm outer‐diameter implants with external and internal hex connection types were constructed. The abutments were designed with diameters of 3.5 mm (platform switching [PS] with 1 mm of diametral mismatch [PS − 1]), 4.0 mm (PS with 0.5 mm of diametral mismatch [PS − 0.5]), and 4.5 mm (conventional matching implant–abutment design [CD]). Analysis of variance at the 95% confidence interval was used to evaluate peak equivalent strain (EQV strain) in the bone, bone volume affected by a strain >4,000 με (EQV strain >4,000 με), the peak von Mises stress (EQV stress) in abutment screw, and the bone–implant relative displacement. Results: Similar bone strain levels (EQV strain and EQV strain >4,000 με) were encountered in PS − 1, PS − 0.5, and CD models for immediately placed implants, independent of the connection type. For immediately loaded implants, slightly smaller peak EQV strain and EQV strain >4,000 με were found for PS − 1. However, for both connection types in osseointegrated models, the higher the mismatch size, the lesser the amount of strain found. Conclusions: The increase in mismatch size of PS configuration results in a significant decrease of strain levels in bone for osseointegrated implants, principally for external hex connections. No significant effect of PS could be noted in immediately placed implants.