Rungtiwa Sawatkumjonpong. The effect of loading conditions on various implant-abutment connections . Master's Degree(Prosthodontics). Mahidol University. : Mahidol University, 2004.
The effect of loading conditions on various implant-abutment connections
Abstract:
Nowadays, dental implants have been used worldwide because of their longterm
predictability. However, reviewing studies have reported some mechanical dental
implant complications such as screw loosening, screw fractures and fixture fractures.
Most mechanical complications were reported by clinical data collections or using
single implant experiments. However, there was not enough understanding of the
biomechanics. The aim of the study was to explain the biomechanical effect of 4
fixtures supporting fixed detachable prosthesis.
This study compared the strain deformation at implant-abutment connection by
using strain gauges and stress distribution at implant-abutment connection and fixture
apex by using photoelastic model. This study compared the external implant-abutment
connection (Replace System) model with the internal implant-abutment connection
(Select System) model. The 3 vertical loading conditions (anterior loading condition,
right-side loading condition and 4-point loading condition) were applied using an
Instron machine.
The result of the strain gauge measurement indicated that, the multi-unit
external implant-abutment connection model had average strain (0.25-3.80 μstrain)
more than the internal implant-abutment connection (0.42-3.50 μstrain) model in 3
loading conditions. The photoelastic analysis indicated that there were no different
fringe values between implant-abutment connection and fixture apex in external
implant-abutment connection model. The result of the internal connection model
indicated that there were no different fringe values at fixture apex after 3 loading
conditions but there were different fringe values at implant-abutment connection in 3
loading conditions.
These findings show that loading conditions have been only affected to strain
production on internal implant-abutment connection. Although, among loading
conditions external inplant-abutment connections have caused more strain than
internal implant-abutmment connection. The photoelastic analysis shows that the
fringe values at implant-abutment connection level of internal-implant abutment
connections are less than external implant-abutment connection in all loading
conditions and there were no different fringe values at fixture apex level between
internal and external implant-abutment connection among three loading conditions.