dental implant cement flow simulations with...
TRANSCRIPT
![Page 1: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/1.jpg)
Dental Implant Cement Flow
Simulations with STAR-CCM+ Sabine Goodwin
![Page 2: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/2.jpg)
Missing teeth are replaced by implants
and crowns
It is now common place for dentists to
join crowns and implants using cement
(as opposed to using screws)
– Improved esthetics
– Cost-effective
– Reduced chair-time
Excess cement extrusion into the soft
tissue has been shown to cause long-
term peri-implant disease
Problem Description
![Page 3: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/3.jpg)
Only very limited data is available on how to achieve optimal
cementation and avoid these health issues
Questions to ask :
– How much cement should be used?
– What type of cement should be used?
– Where should the cement be loaded in the crown?
– Can the implant shape be changed?
System control solution : consider the complete implant abutment,
cement and crown system
System Control Solution
![Page 4: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/4.jpg)
STAR-CCM+ is well-positioned and can address these problems
– Understand cement flow patterns of the system
– Explore effects of
• Amount of cement
• Initial cement placement
• Speed of crown seating
– Re-design implant to retain excess cement within the implant abutment
Key features of STAR-CCM+ :
– 3D-CAD
– Overset Mesh
– Volume of Fluid (VOF) Multiphase Model
– Optimate Powered by HEEDS
Simulating the System
![Page 5: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/5.jpg)
Non-Newtonian Properties of Cement
Source : http://portal.daledental.com/files/proddocs/11/RelyX%20ARC%20Technical%20Profile.pdf
Dental cements are non-Newtonian in nature
– Viscosity varies with shear rate
– RelyX™ cement is shear thinning (viscosity decreases with shear rate)
STAR-CCM+ offers several models for simulating non-Newtonian laminar liquids – Herschel-Bulkley model for Bingham
plastics is commonly used
– Input parameters for model were obtained through curve fitting of the RelyX™ cement viscosity vs. shear rate properties
Parameters for Herschel-Bulkley model provided by Nathanael Inkson (CD-adapco)
![Page 6: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/6.jpg)
Implant and Crown Simulation Setup
Overset Mesh Approach – Polyhedral mesh
– Significant refinement to capture free surface and small gap at end position
– Background region for implant is stationary
– Overset region translates down to reflect motion of the crown
Initial cement loading – ½ toroid shape, 1 mm radius
– Located just above margin line
– Defined using a scalar array of volume fraction
Simulation – Transient solution
– VOF (air/cement)
– Laminar flow/Segregated solver
– Non-Newtonian fluid
– Spans 0.5 seconds from starting to ending position
Cross-sectional cut through implant, crown and cement system
100% Cement 100% Air
![Page 7: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/7.jpg)
Animation of Implant Abutment & Crown System
![Page 8: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/8.jpg)
Abutment modifications : Experimental Studies
0
0.05
0.1
0.15
Wei
ght
of
cem
ent
mg.
Closed Open IVA Abutment modification
Implant design : what are we looking for? – Minimal amount residual excess cement enters the
surrounding soft tissue results in reduced peri-implant disease
– Large contact area between cement/implant and crown results in greater retentive capability
– Crown/Implant margin needs to be sealed
Studies performed on three types of abutments : – Closed abutment
– Open abutment
– Internal vent abutment
In-vitro experimental study results : – Leaving screw access hole open improves cement
retention
– Internal vent abutment shows a better infill of the screw access hole
![Page 9: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/9.jpg)
Abutment Modifications : STAR-CCM+
Simulations Open Abutment
– Screw access chamber is left open
• Provides a reservoir for excess cement to be retained inside abutment system
– Leads to :
• Less cement extrusion – Reduced peri-implant disease
– Easier and faster clean-up
• Improved retentive capabilities from increased contact area
Internal Vent Abutment
– Screw access chamber is left open
– Two additional round vents
• 2.5 mm below occlusal surface
• 180 degrees apart
• 1 mm in diameter
– Leads to :
• Further control over cement flow
• Improved retentive capabilities from increased contact area
![Page 10: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/10.jpg)
Abutment Modifications : STAR-CCM+ Validation
100% Cement 100% Air
Closed Abutment Open Abutment Internal Vent Abutment
![Page 11: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/11.jpg)
How much cement should be loaded?
~45 mm3 ~35 mm3 ~30 mm3
![Page 12: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/12.jpg)
How much cement should be loaded?
Amount of cement : ~45 mm3 Amount of cement : ~35 mm3
![Page 13: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/13.jpg)
What application technique should be used?
Cement loaded at crown margin :
• Vents fill up before the screw access hole.
• Overall flow of cement is smooth
• No cement leaves the system.
Cement loaded near occlusal surface:
• Screw access hole fills up first
• Cement is pushed with force
through the vents
• Results in an incomplete margin
seal
![Page 14: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/14.jpg)
What application technique should be used?
Closed abutment with cement loaded
near occlusal surface
Close abutment with cement loaded
at crown margin
![Page 15: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/15.jpg)
How fast should the crown be seated?
Slow : 1 second for seating Fast : .25 seconds for seating
![Page 16: Dental Implant Cement Flow Simulations with STAR-CCM+mdx2.plm.automation.siemens.com/sites/default/... · peri-implant disease Simulation of the complete implant, cement & crown system](https://reader033.vdocuments.net/reader033/viewer/2022053014/5f1145a1129069238b221cad/html5/thumbnails/16.jpg)
STAR-CCM+ was used to investigate the problem of excess cement extrusion that leads to peri-implant disease
Simulation of the complete implant, cement & crown system showed: – Good comparison with experimental
studies : internal vent abutment is the best design
– Amount of cement loaded matters!
– Loading cement near the implant crown margin reduces residual excess cement
– Speed of seating of crown matters!
Future work – Continue current research
– Expand to other application such as cementation during hip replacements
Conclusion