Axial displacements in external and internal implant‐abutment connection

Abstract

Internal tapered conical connection demonstrated a varying amount of axial displacement with tightening torque and cyclic loading.

Impact of Intentional Overload on Joint Stability of Internal Implant‐Abutment Connection System with Different Diameter

“…Also, compressive force could generate elastic and plastic deformation of the implant/abutment interface, inducing further insertion of the abutment . The axial displacement of the abutment can cause various biomechanical complications such as prosthesis misfit, unstable occlusion and prosthesis screw loosening . To prevent these complications, many studies have focused on the amount of axial displacement after tightening torque or physiologic cyclic loading …”

“…To determine prosthetic treatment protocol and maintain stable occlusal contact, the converging point in axial displacement of the abutment must be confirmed. Upon cyclic loading within a range of average physiologic occlusal force from 150 to 250 N, axial displacement has been self‐limited, in amounts reported to be less than 9 μm, which is within the threshold of the occlusal tactile perception . Although the resultant occlusal discrepancy is within the physiologic threshold, a sensitive patient with high perception ability could discriminate it with complaint .…”

The effect of repeated torque tightening on total lengths of implant abutments in different internal implant‒abutment connections

“…It is due to a lack of certain vertical stop in morse 11°, wherer the taper abutment enters the internal parts of the implant, leading to vertical displacement. 14 However, based on our study, combination of morse hex exhibited lower vertical displacement compared with hex. It can be said in justification that vertical stop, which is identical in morse hex and hex and causes vertical displacement in morse hex, is not more than hex.…”

“…These vertical discrepancies are associated with rotational freedom, this means that the horizontal and rotational discrepancies can cause strains in superstructures; if it does not cause bone loss, it will lead to mechanical complications, like screw, framework and the veneer fracture. 14 …”

Technique to retrieve implant abutment fragments

“…Preloading the abutment screw and occlusal loading could wedge the fractured abutment into the implant and require high pull-out force. 16,17 Saliva, blood, and the limited visibility of the dental implant make it difficult to access. The separation and retrieval of a fractured abutment wedged inside the implant require direct access and delicate manipulation to prevent damage to the internal part of the implant.…”