Stability of Mandibular Overdentures Before and After Attachment Wear. An in vitro Study

Abstract

Abstract:Purpose: The aim of this research was to evaluate and compare the maximum stabilizing force and stabilizing energy of mandibular overdentures with several attachments during anterior, lateral, and posterior dislodgement before and after wear simulation. Changes in the maximum retentive force and maximum stabilizing force of each attachment during various levels of wear simulation were also examined. Methods: Ten samples, each of 8 different overdenture attachments, were sequentially embedded in mandibular overdentures in pairs. Maximum stabilizing force and stabilizing energy were measured during anterior, lateral, and posterior dislodgement by a universal testing machine before and after wear simulation. A total of 5000 insertion-removal cycles were performed. The maximum retentive force of each sample was measured during various levels of wear simulation by a micro material testing machine. Results: The mean maximum stabilizing force ranged from 1.94N to 28.6N, and the mean stabilizing energy ranged from 1.9N•mm to 30.24N•mm before wear simulation. After wear simulation, the values ranged from 1.03N to 20.49N for maximum stabilizing force and from 1.9N•mm to 21.51N•mm for stabilizing energy. This study revealed a decrease (4.13-84.46 %) and an increase (1.23-41.8 %) in maximum stabilizing force. A decrease (6.5-85.42%) and increase (5.35-23.55%) were also seen for stabilizing energy. Conclusions: Maximum stabilizing force and stabilizing energy can each be used to evaluate the stability of overdentures. Both parameters were different during anterior, lateral, and posterior dislodgement after and before wear simulation. The changes in the maximum retentive force for each attachment during wear simulation were different. Among the attachments tested, Hyperslim 4013 was the least sensitive to wear simulation.

Retention force dynamics of two different soft liners over ball abutments for mandibular implant overdentures

“…In the present study, the test samples have been divided into three groups, group A, group B, group C. In addition to the analysis of retentive forces, deformations and alterations in the matrix area were also analyzed in the previous studies 38,39) by various methods like scanning electron microscopy, co-ordinate measuring machine, and digital light microscopy. In the present study, the qualitative analysis of the deformations of the dual recess' of all the 45 test samples of all three groups done using a stereomicroscope.…”

Effect of Height Differences on the Retention and Wear Behaviour of Ball Attachment System Over Mandibular Dual Implants

“…In addition to the retentive forces, few studies have also evaluated the amount of wear and its effects in the attachment systems. Wear have been assessed using Metallographic microscope [25], Micro material testing machine (MTM) [15,[26][27][28], Coordinate measuring machine (CMM) [18], Scanning electron microscopy (SEM) [14,29], and stereo microscopy [6,17]. The positioning of the implant overdenture attachments is very important for two-implant overdentures.…”