Recommended Resin: DC12/ DM Model Resin
Shining 3D offers DC12 for dental casting application. DC12 is a printable wax-like photopolymer specially developed for investment casting. This is the resin for dental applications such as crown and bridge casting and partial denture framework casting.
It burns out clean and can be also used in the pressed ceramic applications.
This application guide demonstrates each step from 3D scanning to 3D printing on AccuFab printers with normal resin tank (1 bottle DC12 resin).
Use the current workflow to ensure a high satisfaction result.
Scan
Dental design software requires a digital impression with Aoralscan intraoral scanners of the patient’s dentition anatomical data in order to design surgical guide applications.
Before designing for the surgical guide, the anatomy of the patient’s hard tissue structure with CBCT is required.
Design
Shining 3D would recommend some 3rd party professional software, such as exocad to start the dental casting design. There are two ways to design the cast, design a coping or design a full crown with cut back.
Note: If you would like to know more about the crown design, please refer to Crown & Bridge Application Guide.
One-Click Printing
Crown and Bridge One-Click Printing can be used after importing the files, auto layout, support generation and slicing will be automatically performed with AI algorithm and can be sending to printer for printer. You could check in support adding stage to make sure the models are well performed before slicing to save time.
Manually added support
You can adjust the model to an optimum position and choose the support type “C&B Support”. Place the model with occlusal side facing the platform and avoid fitting surface support added, otherwise this may cause unexpectable result when fitting.
Post-process
Part removal and washing
If you are using the standard ceramic platform, you could straightly select “Cut and Wash” for easy process.
If you are using the small ceramic platform, please be careful when remove the model by scrappers.
Select CB11 or TN11 during washing stage to use the default setting time for the well-washed outcome.
Support Removal
Remove the support after washing. Carefully remove the small part support and you could also use scissors to assist.
Washing
Ultrasonic Machine
Place the model in beaker with optimum amount IPA ≥75% covered. Use Ultrasonic machine (150-500W) around 2 min.
Change a clean beaker with the un-contaminated IPA and wash again. Washing for too long will affect the accuracy and strength of the model.
If you have a strong power ultrasonic machine, please consider to decrease the washing time.
Hand Wash
Please use soft brush to gently clear the model or teeth surface and repeat washing for 1 min. Repeat the above procedure again for one more time.
Drying
Use the compressed air gun dry the cleaned model, please make sure the model surface is fully dried and no excess IPA and residue attaching.
If there is any residues attaching (with obvious reflection showing), please repeat the above cleaning procedure to wash again. After fully dried, place for 5 min and continue the further procedure.
Post-Curing
Place the model in FabCure 2, make sure no stacking model inside the plate. Use the pre-set TN11/CB11 parameter, or set in custom, with no heating and curing for 7 min. After curing, make sure the model to be placed 1-2 hrs for the most stable strength.
Griding
Carefully gride the support added area using small diamond griding head, to avoid the damage of the model surface.
After the griding of the crown/bridge, place the crown/ bridge on the model and die to test the fitting of the margin line. Use the grinding head with 150um (recommended speed 15,000-30,000 rpm/min), with the use of the bite sheet to fix the path of insertion of the crown/ bridge. Use a larger grinding head to adjust.
The perfect result would be the bite paper can be evenly removed from the occlusal teeth with the correct bite.
Sprueing Parts
Sprue the crown or bridge when the products are that fully dried. Add wax sprues on the crown to make it stable similar to lost-wax casting. Add different sprues on different crown, if the crown is difficult to add, you could use superglue or epoxy to attach.
You could add sprues on the cusp to avoid air bubbles during investment and make sure you leave some gap between the crown and the large sprues. Larger gap resists the thermal expansion happening.
Preparing the investment and mold
Make sure you spray the bubble separator on the parts to avoid air bubbles occurring during investment.
Mix the powder according to the ratio applied on the package, different brand of investment will have slightly different ratio. Place in the vacuum mixer and pour on the ultrasonic machine until spillover to avoid air bubbles during investment.
Note: you could attach a bit of the investment around the margin line before start pouring the investment powder.
Leave the mold in room temperature until it cools down.
Burnout procedure
Shining 3D suggest DC12 to develop a burnout procedure at 950 degrees in 1.5 hrs and a maximum procedure around 3 hrs including the accelerating and decelerating stage.
Note: Please be in caution and read your investment powder instruction carefully. If you powder cannot be raised into 950 degrees, please decrease the temperature and longer the burnout time.
Casting
Remove the mold from the furnace and use centrifugal or vacuum casting process to cast. After the cast is fully dried, quench the mold.
Finish
Place on the model to see if the crown fits and start with the continued procedures.