Good stability and retention rely on reliable records. This may mean a custom impression tray if a stock tray does not cover the edentulous arches properly. You can modify a stock tray or send an initial impression to our lab and order a custom tray if this is neccesary. Intraoral scanning of edentulous arches is becoming more common. This requires an intraoral scanner that will capture the soft tissue acurately. Most current generation scanners can do this with reasonable accuracy, however it is critical to scan all areas that a traditional impression would cover.
In both traditional impressions and digital scans it is critical to capture:
Maxilla Residual ridge, maxillary tuberosities and hamular notches The full depth and width of the functional buccal and labial sulci The hard palate and the anterior part of the soft palate
Mandible Residual ridge and retromolar pads The full depth and width of the functional buccal and labial sulci, the frena and the external oblique ridges The lingual sulcus, lingual frenum, mylohyoid ridge and retromolar area. Impressions should be recorded with the mylohyoid contracted. Make sure the distolingual region is recorded
3d printed custom tray with wax rim
A custom tray is designed from the intraoral scan or a scanned model from traditional impression. A wax rim is added to the tray and sent to the doctor for marking of midline and occlusion. All custom trays will be sent with either a stone model or 3d Printed model to facilitate marking/modifying retention areas. Note that it is common practice to take a second and final traditional impression at this point.
Alameter and Papillameter
It is possible to help define the ideal dimensions and tooth placement with some additional measurement tools in the first office visit. The first tool is an alameter which measures the patients nostril width. This guides the dimension between maxilary canine teeth that best fits the patients face. The second is the papillameter which helps define the wax rim length. This measurement of the the vertical distance between the alveolar ridge and the low and high lip line positions allows us to taylor the wax rim to the patient, saving chair time. These can be purchased at https://dentalmasters.com/.
3Shape denture software order definition
When the custom tray has been returned with occlusion and midline marks, it is scanned along with the original impressions and brought into 3Shape software. The type of denture is defined including materials and molar extension.
Teeth selection and positioning
Digital denture design and 3d printing allows us to create an infinate range of teeth types, anatomy and positions. Traditional designs relied on using "Teeth cards" with a limited range of stock choices. Every aspect of a design is custom matched to the doctor (and patients) requirements. Occlusion is adjusted digitally to achieve ideal group function.
Gingiva function and anatomy
The giniva function can be modified to fit the patient perfectly and anatomy crafted to match the best hand waxed designs.
3D printed try in
When the design is optimized it is sent to a 3d printer to create a monolithic try in. This is diffent from traditional denture wax tryins where a doctor is required to set the ideal teeth position and function. Digital design and 3D printing create a situation where the doctor simply makes notes about the changes they would like to see and pass them to our lab. Most often it is something as simple as "move midline 1mm to patients right, increase anterior length by 1.5 mm, reduce molar occlusion by 1mm. These changes can be quickly made in the software design and either a new tryin sent or if the changes are minimal, the final denture is poduced. Because the tryin material is class 2 rated, the patient can wear it for a few days before the final adjustments to the design are made.
Final Denture Production
Teeth and gingiva are produced on our 3D printers using the leading edge materials and then bonded together and finished. The well known denture material brand, Lucitone, has recently released 3D printer resin that equals or surpasses traditional denture materials all key performance metrics.
Final results
3D printed digital dentures can match and surpass the finest hand crafted tranditional designs. They can be simple and cost effective or hand charactorized for truly amazing results. More importantly they offer superior fit and can be duplicated at a reduced cost for broken and second sets.
