The micromechanical behavior of implant‐abutment connections under a dynamic load protocol

Schlee, Markus; Weigl, Paul; Ratka, Christoph; Lange, Bodo; Lauer, Hans–Christoph

doi:10.1111/cid.12651

Cited by 42 publications

(41 citation statements)

References 17 publications

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“…The presence on the marketplace of screws especially designed to prevent loosening, such as those plated in gold, stands as proof of the importance attached to the problem. While some studies report higher reverse torque values [19,33] with gold-plated screws [43,50,51], no consensus has been reached in this regard [18,39]. The high cost of gold-plated screws is a significant drawback that both precludes their routine use and determines their relegation to specific clinical situations such as the loosening of a titanium screw.…”

Section: Discussionmentioning

confidence: 99%

A Novel Technique Using Polytetrafluoroethylene Tape to Solve Screw Loosening Complication in Implant-Supported Single Crowns

Felix

Medina

Gómez‐Polo

et al. 2020

IJERPH

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This study aimed to analyze a novel technique to make screws with greater untightening resistance and to solve screw loosening in implant-supported single crowns. Thirty grade IV titanium straight abutments were screwed onto 30 external hex implants using grade IV titanium screws (30 Ncm). They were exposed to cyclic loading (300,000 cycles, 200 N). Samples were divided into 4 groups (15 samples per group): new screws (SCREW group) (control), reused screws (rSCREW group), new screws wrapped with polytetrafluoroethylene (PTFE) tape (PTFE group), and reused screws wrapped with PTFE tape (rPTFE group). Reverse torque values (RTVs) were recorded with a digitally calibrated implant motor. Mean RTVs observed were 14.46 N (±1.10 N) for the control group, 14.42 N (±1.22 N) for the rSCREW group, 19.97 N (±1.16 N) for the PTFE group, and 19.13 N (±2.38 N) for the rPTFE group. Statistically significant differences were found between RTVs of both groups employing screws without PTFE tape (SCREW and rSCREW groups) compared with those using screws wrapped with PTFE tape (PTFE and rPTFE) (p < 0.001). These results suggest that wrapping the implant–abutment screw with PTFE tape may effectively lower the risk of loosening and even constitute a solution when this complication occurs in implant single crowns.

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Section: Discussionmentioning

confidence: 99%

A Novel Technique Using Polytetrafluoroethylene Tape to Solve Screw Loosening Complication in Implant-Supported Single Crowns

Felix

Medina

Gómez‐Polo

et al. 2020

IJERPH

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“…7 Evidence has shown that fabrication tolerance, connection design, abutment material, and insertional torque can all affect the stability and integrity of the implant-abutment interface. Direct techniques such as scanning electron microscopy (SEM), 10 x-ray micro-computed tomography (micro-CT), 11 and synchroton radiography 12 capture 2D or 3D images of the gap directly. 9 The techniques employed for investigating the implant-abutment interface reported in the literature can be classified as direct and indirect ones.…”

mentioning

confidence: 99%

“…9 The techniques employed for investigating the implant-abutment interface reported in the literature can be classified as direct and indirect ones. Direct techniques such as scanning electron microscopy (SEM), 10 x-ray micro-computed tomography (micro-CT), 11 and synchroton radiography 12 capture 2D or 3D images of the gap directly.…”

mentioning

confidence: 99%

Contact analysis of gap formation at dental implant‐abutment interface under oblique loading: A numerical‐experimental study

Fok

Aparicio

et al. 2019

Clin Implant Dent Rel Res

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Purpose: To develop numerical and experimental methods for investigating the formation of micro-gaps and the change in contact area at the implant-abutment interface of two different connector designs under oblique cyclic loading.Materials and Methods: Samples (n = 10 per group) of two-piece implant systems with the conical connection (group A) and the external hexagonal connection (group B) were subjected to cyclic loading with increasing load amplitudes up to 220 N.After loading, the samples were scanned using micro-CT, with silver nitrate as a highcontrast penetrant, and the level of leakage was assessed using a discrete scoring system. Three-dimensional finite element (FE) analyses of the two implant systems were also conducted to reveal the micro-gap formation process, especially bridging of the internal abutment screw space. The experimental and numerical results for the bridging load were then compared.Results: 90% of the samples in group A showed leakage into the internal implant space at a load of around 100 N; while over 80% of those in group B did so at a load of around 40 N. This agreed with the FE analysis, which showed bridging of the internal implant space at loads similar to those measured for the two implant systems.Residual gaps of less than 1.49 μm were predicted for group A only after unloading. Conclusions:The FE-predicted loads for bridging agreed well with those found experimentally for leakage to occur. The conical connection showed more resistance against formation of micro-gaps at the implant-abutment interface than the external hexagonal connection. Although the minimum load required to bridge the internal implant space was within the range of human biting force, the relation between bacterial invasion and micro-gaps needs further research. K E Y W O R D S finite element analysis, implant connection design, implant-abutment micro-gap, microcomputed tomography

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“…The microgap would affect the bacterial microleakage of the implant, which is related to the peri-implantitis. 30 31 The larger microgap means the higher deformation of titanium, and the deformation of titanium results in the stress of the implant.…”

Section: Discussionmentioning

confidence: 99%

Biomechanical stress and microgap analysis of bone-level and tissue-level implant abutment structure according to the five different directions of occlusal loads

et al. 2020

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PURPOSE The stress distribution and microgap formation on an implant abutment structure was evaluated to determine the relationship between the direction of the load and the stress value. MATERIALS AND METHODS Two types of three-dimensional models for the mandibular first molar were designed: bone-level implant and tissue-level implant. Each group consisted of an implant, surrounding bone, abutment, screw, and crown. Static finite element analysis was simulated through 200 N of occlusal load and preload at five different load directions: 0, 15, 30, 45, and 60°. The von Mises stress of the abutment and implant was evaluated. Microgap formation on the implant-abutment interface was also analyzed. RESULTS The stress values in the implant were as follows: 525, 322, 561, 778, and 1150 MPa in a bone level implant, and 254, 182, 259, 364, and 436 MPa in a tissue level implant at a load direction of 0, 15, 30, 45, and 60°, respectively. For microgap formation between the implant and abutment interface, three to seven-micron gaps were observed in the bone level implant under a load at 45 and 60°. In contrast, a three-micron gap was observed in the tissue level implant under a load at only 60°. CONCLUSION The mean stress of bone-level implant showed 2.2 times higher than that of tissue-level implant. When considering the loading point of occlusal surface and the direction of load, higher stress was noted when the vector was from the center of rotation in the implant prostheses.

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The micromechanical behavior of implant‐abutment connections under a dynamic load protocol

Abstract: Within the limits of the present in vitro study, X-ray imaging showed reduced formation of microgaps and consecutive micromovements in implants with conical IAC compared to flat IACs.

Cited by 42 publications

References 17 publications

A Novel Technique Using Polytetrafluoroethylene Tape to Solve Screw Loosening Complication in Implant-Supported Single Crowns

A Novel Technique Using Polytetrafluoroethylene Tape to Solve Screw Loosening Complication in Implant-Supported Single Crowns

Contact analysis of gap formation at dental implant‐abutment interface under oblique loading: A numerical‐experimental study

Biomechanical stress and microgap analysis of bone-level and tissue-level implant abutment structure according to the five different directions of occlusal loads

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