Case Study
3D Printed Full & Partial Dental Crowns
This case study explores a streamlined workflow for designing, fabricating, and finishing full and partial dental crowns using cutting-edge 3D printing technology. Taking you step by step, we’ll delve into how we used industry-leading software like Exocad for meticulous design and SprintRay 3D printers to efficiently produce superb restorations.
Advanced design with exocad
Leveraging advanced dental design software like exocad, we work with the scanned data to meticulously design crowns or partial crowns that integrate seamlessly with your oral anatomy. These software packages offer a plethora of features, including:
- Virtual tooth libraries for efficient tooth morphology replication.
- Shade-matching tools which achieve natural-looking aesthetics.
- Anatomical customisation options to fine-tune the gap and thickness of the restoration for optimal fit and function.
This meticulous design approach ensures a perfect result for each patient, balancing functionality with lifelike aesthetics.
Optimised nesting for efficiency
Once designs are finalised, nesting software comes into play. Nesting strategically arranges multiple crowns or partial crown designs within the virtual print space, maximising resin usage and minimising printing time. Additionally, we optimise printing results by adjusting the angle of the restoration within the print bed to ensure it is built up with superb strength and accuracy. Software like Ackuretta Alpha AI and SprintRay’s RayWare Cloud offer automated nesting algorithms and collision detection to ensure error-free printing with optimal efficiency.
Precision 3D printing
Once the nested design is completed, it is sent to the 3D printer. For this application, we utilise hybrid resin which offers enhanced durability, precision and biocompatibility.
Streamlined finishing techniques
Support removal: We use flush cutters to clip off the support structures from the printed parts. Any stubs which may remain on the crowns are later removed during polishing.
Polishing: Surfaces are meticulously polished to achieve a smooth and natural finish, mimicking the texture of natural teeth.
Support removal: For ceramic-filled resin, the cleaning process begins with a 30-second wash in IPA using a shaker. This is followed by spraying the surfaces and grooves with alcohol and cleaning them with a micro brush. We then use compressed air drying to ensure no moisture remains on the surface.
Glycerine post-curing: A thin coat of glycerine is applied to eliminate oxygen and prevent oxygen inhibition, allowing the resin to cure fully. This step is followed by a final high-intensity cure using a unit like the SprintRay PoCure2, ensuring maximum strength and longevity of the prosthetic.
Lifelike characterisation
For optimal aesthetics, characterisation techniques involving stains, glazes, and textures can be meticulously applied to mimic the natural colour variations of surrounding teeth. Light curing is employed throughout the characterisation process to ensure proper adherence of each layer.
Simulation of insertion
Before final placement, a mock-up wax-up, a temporary replica of the crown or partial crown, can be created to:
- Visually assess aesthetics, ensuring a seamless integration with surrounding teeth.
- Evaluate fit and function, verifying proper bite and articulation before permanent placement.
Crownlay fissure seal with LiSi ceramic
This case study highlights a patient with a cracked tooth experiencing sensitivity due to exposed dentin. To address these concerns while preserving healthy tooth structure, we opted for a minimally invasive approach using a lithium disilicate (LiSi) crown.
Traditionally, crown placement necessitates some reduction of the buccal surface (cheek-side). However, in this case, a thin, durable, and biocompatible LiSi ceramic material was utilised to achieve full coverage without sacrificing healthy tooth structure. This approach minimises potential discomfort and promotes long-term gingival health.
The LiSi crown was 3D printed using a Class V design, ensuring optimal coverage of the exposed dentin and alleviating the patient’s sensitivity. The patient will return for a follow-up appointment for final finishing, where the crown will be polished to achieve a natural-looking finish, similar to composite resin.
