Stress distribution pattern of screw-retained restorations with segmented vs. non-segmented abutments: A finite element analysis

Abstract

Background. Screw-retained restorations are favored in some clinical situations such as limited inter-occlusal spaces. This study was designed to compare stresses developed in the peri-implant bone in two different types of screw-retained restorations (segmented vs. non-segmented abutment) using a finite element model. Methods. An implant, 4.1 mm in diameter and 10 mm in length, was placed in the first molar site of a mandibular model with 1 mm of cortical bone on the buccal and lingual sides. Segmented and non-segmented screw abutments with their crowns were placed on the simulated implant in each model. After loading (100 N, axial and 45° non-axial), von Mises stress was recorded using ANSYS software, version 12.0.1. Results. The maximum stresses in the non-segmented abutment screw were less than those of segmented abutment (87 vs. 100, and 375 vs. 430 MPa under axial and non-axial loading, respectively). The maximum stresses in the peri-implant bone for the model with segmented abutment were less than those of non-segmented ones (21 vs. 24 MPa, and 31 vs. 126 MPa under vertical and angular loading, respectively). In addition, the micro-strain of peri-implant bone for the segmented abutment restoration was less than that of non-segmented abutment. Conclusion. Under axial and non-axial loadings, non-segmented abutment showed less stress concentration in the screw, while there was less stress and strain in the peri-implant bone in the segmented abutment.

Finite Element Analysis of Dental Implants with Zirconia Crown Restorations: Conventional Cement-Retained vs. Cementless Screw-Retained

“…These results are consistent with those of previous studies [21,22]. A photoelastic stress analysis by Ochiai et al [21] showed that non-segmented abutments under vertical loading generate more stress in the bone compared to segmented abutments.…”

“…A photoelastic stress analysis by Ochiai et al [21] showed that non-segmented abutments under vertical loading generate more stress in the bone compared to segmented abutments. Another study suggested that segmented abutments show biomechanical benefits in terms of a decrease in stress concentration and microstrain in bone [22]. They found that a greater part of the stress might be detected in the prosthetic components (abutments and screws) before reaching the bone-implant contact area.…”

Stress distribution in prosthetic abutments: a finite element analysis comparison of conical and UCLA abutments

“…These results may be related to the segmented structure, which is capable to improve biomechanical behavior with the presence of two screwed connections in the conical abutment and increase the total area for stress/strain distribution and dissipation through the components (Camargos et al, 2016). These results are consistent with previous studies, which demonstrated that non-segmented abutments generate higher stress compared to segmented abutments (Ochiai et al, 2003;Aalaei et al, 2017).…”

“…Studies suggest that the use of the prosthetic segmented abutments is directly related to a better distribution of stress (Chun et al, 2005;Aalaei et al, 2017). The implant-abutment connection is believed to play an important role in the treatment outcome.…”

Análise de tensões pelo método dos elementos finitos em implantes dentários com plataforma cone morse

“…Dado semelhante pode ser encontrado em estudos utilizando de implantes envolvendo cargas oblíquas a 45º em carregamentos de 100 N de compressão, simulados em região de mandíbula, apresentaram valor máximo de tensão de von Mises em torno de 524 MPa 17 , o que representou uma diferença de 8,7% em relação à literatura. Valores aproximados puderam ser notados para a mesma situação em estudos realizados por Aalaei et al (2017) 18 , sendo que foi verificado nos pilares, máxima concentração de tensão de von Mises (430 MPa) 18 , confirmando que o presente estudo tem aproximação com os resultados encontrados na literatura em estudos similares.…”