Fatigue resistance of a simulated single LOCATOR overdenture system.

Abstract

STATEMENT OF PROBLEM:

The incidence of fracture in a single-implant overdenture base increases in the region adjacent to the fulcrum implant.

PURPOSE:

The purpose of this in vitro study was to evaluate the effect of bidirectional woven electrical glass (E-glass) fiber reinforcements on the fatigue resistance of a simulated single LOCATOR-retained overdenture.

MATERIAL AND METHODS:

Test specimens with a centrally positioned metal housing for a LOCATOR stud attachment were fabricated from autopolymerizing acrylic resin. Specimens for the control group were fabricated without glass fiber reinforcements. The 4L group specimens had 4 layers of E-glass fiber weaves and were divided according to the fiber location into the following 3 subgroups: 4L-A with 4 fiber layers above the metal housing; 4L-N with 4 fiber layers adjacent to the metal housing; and 4L-A+4L-N with 4 fiber layers above and 4 fiber layers adjacent to the housing. Specimens were stored in distilled water for 1 week at 23 °C before cyclic fatigue testing at 10 000 cycles by using a staircase approach (n=12). The results were analyzed with 1-way ANOVA and the Tukey multiple comparisons post hoc analysis (α=.05). A 2-way ANOVA (α=.05) was conducted to detect the effect of fatigue cyclic loading and the position of the fiber layers and their interaction on the fatigue resistance.

RESULTS:

The results of the investigated compressive fatigue limits for the test groups were 190 ±15.9 N for the control group, 265 ±15.9 N for the 4L-A subgroup, 220 ±15.9 N for the 4L-N subgroup, and 275 ±15.9 N for the 4L-A+4L-N subgroup. A nonsignificant difference was found for creep values between the control group and reinforced subgroups (P>.05). The postfatigue flexural strength values in the 4L-A and 4L-A+4L-N subgroups were significantly higher than those in the control group (P<.001) and the 4L-N subgroup (P=.004 and P=.005). However, no significant difference was found in postfatigue flexural strength between the control group and the 4L-N subgroup (P=.828).

CONCLUSIONS:

Placing 4 layers of bidirectional E-glass fiber weaves above the metal housing can increase the fatigue resistance and the postfatigue flexural strength of single LOCATOR-retained overdentures.

• Authors: Mona Gibreel, Lippo V J Lassila, Timo O Närhi, Leila Perea-Lowery, Pekka K Vallittu
• Journal: The Journal of prosthetic dentistry (J Prosthet Dent) Vol. 122 Issue 6 Pg. 557-563 (Dec 2019) ISSN: 1097-6841 [Electronic] United States
• PMID: 30982623 (Publication Type: Journal Article)
• Copyright: Copyright © 2018 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Chemical References

• Acrylic Resins

Topics

• Acrylic Resins
• Dental Stress Analysis
• Denture, Overlay
• Glass
• Materials Testing
• Stress, Mechanical