Failed Orthodontic PEEK Retainer: A Scanning Electron Microscopy Analysis and a Possible Failure Mechanism in a Case Report

Abstract

This study presents a scanning electron microscopy analysis of a failed PEEK retainer in an orthodontic patient. After 15 months of use, the patient reported a gap opening between teeth 41 and 42. The PEEK retainer was removed and sent for electron microscope analysis. To investigate the failure, scanning electron microscopy was employed to assess the microstructure and composition of the retainer at various magnifications. These findings suggest that the failure of the PEEK retainer was multifaceted, implicating factors such as material defects, manufacturing flaws, inadequate design, environmental factors, and patient-related factors. In conclusion, this scanning electron microscopy analysis offers valuable insights into the failure mechanisms of PEEK retainers in orthodontic applications. Further research is necessary to explore preventive strategies and optimize the design and fabrication of PEEK retainers, minimizing the occurrence of failures in orthodontic practice.

Keywords: orthodontic relapse; orthodontic retainer; polyetheretherketone; scanning electron microscopy SEM.

Figure 1

Final photo with retainer applied.

Figure 2

Photo after 15 months; note the opening of the space between teeth 41 and 42 due to orthodontic relapse.

Figure 3

Scanning electron microscopy images; note the smooth and compact surface of the material.

Figure 4

Scanning electron microscopy image; note how the material begins to delaminate and there is widespread bacterial contamination.

Figure 5

Delamination detail.