Editorial Type:
Article Category: Research Article
 | 
Online Publication Date: 09 Mar 2021

Evaluation of Changes in the Mechanical Properties of O-Ring in One Piece and Two Piece Ball Retained Implant Supported Overdentures: A Three-Year Retrospective Study

MDS and
MDS
Page Range: 105 – 109
DOI: 10.1563/aaid-joi-D-20-00151
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The O-rings in ball retained overdentures deteriorate with time and need replacement to restore the retentive quality. We evaluated retrospectively the mechanical properties of O-rings after 3 years in function in 1 and 2-piece implant-supported overdentures. The O-rings were retrieved from one-piece (Myriad snap, Equinox-Straumann, 3.3 × 13 mm) and 2-piece (Neo Biotech, 3.3 × 13 mm) implant-supported overdenture patients. A total of 16 pairs of matrices were tested for wear, type of damage, and elasticity using Pin on Disc method, USB Digital Camera in 30× zoom and Universal Tensile Machine, respectively. The statistical analysis for independent groups were done with the Mann-Whitney U test. Assessment of used O-rings showed 84% more wear in the 2-piece system with an abrasive type of damage while 46% wear in the 1-piece system with a compressive type of damage. The O-rings in 1-piece system showed increase in elongation and maximum displacement to 2% and 7%, respectively, whereas the 2-piece system showed decrease in elongation and maximum displacement by 13% and 6%, respectively. In 1-piece system, the loss of retention was more with slow wear rate, and in 2-piece system, the wear resistance of O-rings decreased due to increased stiffness. Further studies to evaluate the changes in O-ring with increased sample size and at interval 1 year will pave way for insight into the progressive changes in the mechanical properties of an O-ring.

Figure 1.
Figure 1.

One-piece implant system.


Figure 2.
Figure 2.

Two-piece implant system.


Figure 3.
Figure 3.

Compressive type of damage in 1-piece system.


Figure 4.
Figure 4.

Abrasive type of damage in 2-piece system.


Contributor Notes

Corresponding author, email: anand_anandhi@hotmail.com
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