The effect of varying the position of implant screw access opening on the stress distribution of sealing composite resin: a 3D-FEA study
摘要
The aim of this study was to assess the mechanical differences of composite resin sealing the screw access channel with different-positioned openings by a three-dimensional finite element analysis.
MethodsA 3D finite element model of dental implant at the site of mandibular first molar was established using computer-aided design (CAD). Models of sealing composite resin with different thicknesses were applied under 200 N static loading, and the optimal thickness was then selected via stress distribution analysis of composite resin models. Angulated screw channel (ASC) was used to vary the position of implant screw access opening. 200 N static loading was then applied to composite resin models with the selected thickness at different stages of a chewing cycle, and the stress of sealing composite resin in screw access channel with different-positioned openings was compared.
ResultsThe stress within composite resin model was stably at a lower level when the thickness was no less than 3 mm. Varying the position of implant screw access opening influenced stress distribution of sealing composite resin. In contrast with the opening located at central fossa, both maximum von Mises stress and shear stress of sealing composite resin (4.503 MPa and 1.032 MPa) was reduced when the opening was on the lingual side of central fossa (3.974 MPa and 0.9464 MPa) but was increased when the opening was on the buccal side of central fossa (5.695 MPa and 2.162 MPa).
ConclusionsThe stress was significantly lower at the site of mandibular molar when the position of screw access opening was designed on the lingual side of central fossa. Within the limits of the present in silico investigation, this study provided a new design strategy for screw-retained implant prosthesis to reduce the mechanical complications caused by the incomplete sealing of screw access opening.