Implant Screw Mechanics and the Settling Effect: An Overview

Abstract

One of the most serious and prevalent problems associated with the restorative aspect of dental implants is loosening and fracturing of screws. Implant screws should be retightened 10 minutes after the initial torque application as a routine clinical procedure to help compensate for the settling effect. Mechanical torque gauges should be used instead of hand drivers to ensure consistent tightening of implant components to torque values recommended by implant manufacturers.

Influence of eccentric cyclic loading on implant components: Comparison between external joint system and internal joint system

“…Then, in addition to surface roughness, secondary factors such as the material, screw head, and thread design also have to be taken into consideration [5][6][7][8] . Furthermore, several other factors can exert a major influence on screw loosening, such as the structural design of the implant connection, a poor fit with an implant-supported prosthetic crown, and occlusal loading [9][10][11][12] .…”

“…Furthermore, several other factors can exert a major influence on screw loosening, such as the structural design of the implant connection, a poor fit with an implant-supported prosthetic crown, and occlusal loading [9][10][11][12] . Several studies have reported that occlusal forces are the most detrimental factor of screw loosening 5,13) . Occlusal forces are complex in vector and magnitude, and eccentric loading due to such forces, in particular, may influence the implant/abutment connection, resulting in screw loosening.…”

Management Of Abutment Failure Of Mandibular Implant Supported Over Denture: A Case Report

“…However, under functional loading, the initial tensile preload is loosened by a factor known as the settling effect. [8] In view of the importance of correct torque application in the initial phase of tightening, a torque control wrench is recommended for the procedure. [9] Additionally, implant systems with antirotational components, such as an internal hexagon, as well as those in which the abutment engages deep into the implant body, will enhance the strength of the system.…”

Influence of internal connection length on screw loosening in internal connection implants

“…5,6 Consequently, 김지선 1a •박영범 1,2a •최현민 1 •김성태 3 •김현철 4 •김선재 5 •문홍석 traction force between the abutment and the implant fixture occurs due to the elastic recovery of a screw, and a clamping force of the same strength tightens the screw. 5,6 Thus, the stability of the screw joint is directly associated with the preload, and it is influenced by the chewing force, the intensity of the torque, the correct connection with the abutment, and the anti-rotation resistance force.…”