JANUARY 2017 REVOLUTIONIZING the Complete Denture Process
A Complete Prosthesis in 3 Visits Historically, milling has been the most common production technology associated with the fabrication of dental restorations. We are entering the next phase of technology adaptation, involving 3D printing for production purposes. The following case demonstrates how the Pala Digital Dentures system from Heraeus Kulzer allowed the practitioner to deliver a complete prosthesis to a fully edentulous patient in three appointments. Without the need for custom trays, multiple visits were saved as the clinician took the final impression, recorded the VDO, captured the bite, took an excellent gothic arch tracing, and measured the length of the teeth in a truly streamlined process. The process also empowered the dental laboratory to produce complete dentures with improved quality, especially with regard to fit. From a business perspective, it allows laboratories to increase capacity without the need for any additional labor or associated overhead. The system also provides a backup when situations arise that affect the laboratory's production capacity, ie, unforeseen turnover, a big influx of cases, vacation schedules, or illness. Meanwhile, it allows small to medium-sized fixed laboratories to enter the growing removable space. The ultimate benefactor is the patient. The reduction in chair time improves the overall treatment experience, and the excellent fit ensures functionality and confidence.
Case Report: Initial Stages An examination revealed that her maxilla had lost a significant amount of bony support, leaving a relatively flat ridge along with a very small vestibular space. The ridge was especially resorbed in the anterior region due to her lower supra-erupted teeth. The teeth had an uneven occlusal plane (Figure 1) and were monoplane in design. The lower partial fit well, but the alignment of her lower right posterior teeth was off the occlusal plane and based on the occlusion of her upper denture. Her vertical dimension was slightly over-closed. 1 A 73-year-old woman presented with a complete upper denture fabricated more than 15 years prior and a lower partial denture made within the past 5 years. Her chief desires were a more esthetic look unlike her existing worn denture teeth; wanting to show more teeth in her smile; a better fit, which equated to more retention; and to chew better. CLINICAL PROCEDURE Using the Pala Digital Dentures process and tools, the clinician took all necessary impressions and records in one visit, filled out the Pala prescription, and sent it to the laboratory. In this case, the clinician wrote on the prescription that they would be raising the lower right teeth on the partial to create the ideal occlusal plane for the upper denture. The lingualized occlusion option with 20 teeth was selected. CASE COURTESY OF: David Avery, CDT Drake Precision Dental Laboratory Charlotte, North Carolina Lou Graham, DDS University Dental Professionals Chicago, Illinois Source: Inside Dental Technology (December 2016) https://idt.cdeworld.com/courses/5036
Case Report: Refining and Designing At the try-in appointment, a pickup impression of the lower partial was taken, such that the laboratory could raise the lower right teeth on the partial to match the prescribed ideal occlusion for the upper prosthesis from the first appointment. LABORATORY PROCEDURES Upon receipt of the case, the laboratory technician read the prescription thoroughly and scanned the impressions and bite registration with a 3Shape D800 scanner (3shape.com). The resulting STL files were sent to the Pala centralized manufacturing facility for the design and fabrication of a 3D printed prototype. 2 The dentist had the choice of requesting a 3D printed full model or a 3D printed model of the base with a waxup of the teeth, and the latter was selected. This way, the dentist and patient could select the tooth color at the initial appointment and have the teeth set-up on the same 3D model for the try-in appointment to confirm the tooth color and also, if needed, to modify the setup or the occlusion at this appointment. In this case, the clinician decided to adjust the occlusion with a new wax bite. The unique, proprietary software allowed the CAD designer to determine tooth position based on the data from the scanned impressions, registrations, and lip measurements. This further reduced clinical appointment time by eliminating many of the traditional record achievements normally required. The remaining determinations were derived from the algorithms in the software. Twenty-six anatomical landmarks found in every patient were used, including the incisive papilla, midline suture, fovea palatine, and retromolar pads. The measurements associated with occlusion rims illustrated the application of these anthropometric averages. The design was accomplished from these accumulative data points as seen in Figure 2.
Case Report: Final Delivery Based on these findings, Heraeus Kulzer chose to 3D print a fully contoured prototype for the clinical try-in to streamline the fabrication process, bringing the 3D printing advantage to the marketplace. The curing shrinkage associated with this particular printer and material combination results in less than 1% polymerization shrinkage, assuring an excellent fit. The prototype was then converted to a functional prototype (stabilized wax prototype), utilizing the highly accurate printed base fitted with wax-attached Mondial prosthetic teeth (Heraeus Kulzer). The functional prototype was sent to the laboratory for evaluation and delivery to the clinician (Figure 3). This hybrid offering is unique within the digital denture category. It allows the clinician to manage the case as usual by refining anterior tooth position and, where indicated, take a check bite for occlusal refinements by the laboratory technician. This maintains and preserves the original laboratory/client relationship. Upon achieving a satisfactory try-in, the case was returned to the centralized manufacturing facility for completion. The usual shades of methyl methacrylate resin were available for processing with a proprietary injection method, ensuring minimal polymerization shrinkage and a superior clinical fit. The final delivery required no adjustments on the flanges and the retention was excellent. There were slight adjustments to refine centric occlusion on the bicuspids and to teeth Nos. 9 through 11 to harmonize the excursive function (Figure 4). The final denture can be seen in Figure 5. 3 4 5
Case Report 2: A Digital Denture Procedure 1 2 A patient presented with a reasonably functional and esthetic existing complete maxillary denture, requesting a replacement. The Pala Digital Denture was prescribed. From a clinician s point of view, the tray selection and impression making for a Pala Digital Denture turned 3 appointments into 1. Once the tray size was determined by try-in, final impressions were made without the need for preliminary impressions and custom trays. A heavy bodied PVS material (FlexiTime VPS) was used in the tray to capture the impression. Any spots that rubbed through to the tray were adjusted and the impression was relined with lightbodied material (Figure 1). During the reline, border movements were captured by manipulating and pulling on the patient s lips and cheeks while holding the tray in place on the hard palate. To cut and remove posterior tray segments, a line was drawn with a fine-tipped marker to coincide with the posterior portion of the maxillary impression tray. It needed to be accurately separated so that the mandibular impression (or bite plate) could be placed and bite record and tracing could be taken without interference from the posterior border, preventing closure. For the Centric Relations Record, using the Gothic Arch Tracing Device on the maxillary impression, and VDO pin on the mandibular impression or bite plate, the VDO was established by screwing the pin to the desired height to coincide with the patient s preoperative OVD (Figure 2). The existing VDO was recorded. To establish VDO to match, once the vertical height of the pin correctly matched the preoperative VDO, a tracing was performed to record mandibular border movements. CASE COURTESY OF: David Avery, CDT Drake Precision Dental Laboratory Charlotte, North Carolina Robert A. Lowe, DDS Private Practice Charlotte, North Carolina Source: Inside Dental Technology (August 2015) https://idt.cdeworld.com/courses/4940
Case Report 2: Predictable, Streamlined Techniques The Gothic Arch Tracing was performed by the pin on the slate, which had been applied to the center (palate) of the maxillary impression. The Centric Relation position was recorded by the pin on the slate, and that position was dimpled into the maxillary tray so the patient could repeatedly close into CR accurately. The maxillary and mandibular trays (or bite plane) were secured together with bite registration material in the Centric Relation position (Figure 3). A special tool was used to measure lip length at rest and smiling, and those numbers were recorded on the prescription. The remainder of the information on the prescription was filled out any special instructions are noted here and the case was sent to the authorized Pala laboratory for scanning of the impressions. Upon receipt of the case from the dentist, the technician read the prescription thoroughly. The technician scanned the impressions and bite registration, utilizing a D900 scanner (3Shape). The STL files were sent to the Heraeus Kulzer Pala facility for the fabrication of a 3D-printed prototype, which was then returned to the laboratory for try-in. The printed try-in allowed the dentist to evaluate retention, VDO, tooth function and esthetics, phonetics, and occlusion. At this stage, any necessary changes can be noted and another try-in made if necessary. Minimal changes can be incorporated into the final prosthesis without the need for a second try-in visit (Figure 4). Retention, VDO, anterior tooth position for esthetics and phonetics, and centric occlusion were changed in this case. Upon successful completion of the try-in, the case was returned to the laboratory for completion. The technician digitally requested that the case be completed in the appropriate tooth and base resin shades. The case was completed at the Heraeus Kulzer facility and returned for delivery. Upon delivery of the case, the same parameters of retention, VDO, esthetics, phonetics, and occlusion were evaluated. Minor adjustments to occlusion were accomplished using articulating paper and acrylic burs to ensure maximum intercuspation in centric occlusion (Figure 5). 3 4 5
Ease of Collaboration Dirk Albrecht, CDT Oral Designs Dental Laboratory San Antonio, Texas According to Albrecht, Heraeus Kulzer s Pala Digital Dentures deliver exceptional product quality and are backed by truly exceptional customer support. The Pala Digital Denture system delivers a superior fit and excellent esthetics in a fraction of the time of traditional, or analog, dentures. In fact, dentists can capture not just the impression but also the bite registration, vertical dimension, and centric relation in the very first visit, versus three or more visits for analog dentures. Another major benefit comes at the try-in stage, as the digital precision means minimal, if any, adjustment. If any adjustments are required, they are done on the 3D printed prototype and rescanned. Because the denture is modeled digitally and the information is already stored, the fit stays the same regardless of any adjustments made to the teeth set-up, vertical dimension, or lip support. The fit and precision is especially impressive when one considers that Pala Digital Dentures are fabricated in a fraction of the time of analog dentures. While the entire process with analog dentures can take five or six patient visits, only three patient visits are required with the digital approach. That s a huge timesaver for the laboratory, the practice, and the patient, he says. Our laboratory spends a total of only 30 to 60 minutes on a digital denture compared to 4-5 hours with an analog denture. My dentists tell me that the fit and precision of Pala Digital Dentures is significantly better than with analog dentures, Albrecht says. I haven t had one single complaint about any aspect of the process, which is pretty amazing.
New Technology = New Business Dirk Albrecht, CDT Oral Designs Dental Laboratory San Antonio, Texas Albrecht says being able to offer Pala Digital Dentures has been great for business at Oral Designs. Current customers who were not sending their denture business to Oral Designs now do, and the laboratory has added new accounts as well. Albrecht estimates that the new business he was able to generate directly or indirectly because of Pala Digital Dentures helped increase his laboratory s revenues by 15-20%. Albrecht says the single greatest benefit of Pala Digital Dentures is the fact that the overall process is much cleaner and involves far fewer variables. Because of this and the many other advantages of Pala Digital Dentures, the process from start to finish is not only much faster and much more precise but also much more easily repeatable, which dentists value. READ THE FULL TECH INSIDER ARTICLE HERE. One of my customers had grown to hate conventional dentures so much that he had almost completely stopped offering them to his patients, Albrecht says. A few months ago I convinced him to try Pala Digital Dentures, and he s been using them ever since. The other day he said something I never thought I d hear come out of his mouth: You know, I really enjoy doing dentures now. Coming from him, that s pretty remarkable.
About the Company Heraeus Kulzer GmbH is one of the world s leading dental companies with its headquarters in Hanau, Germany. As a trusted partner, the company supplies dentists and dental technicians with an extensive product range, covering cosmetic dentistry, tooth preservation, prosthetics, periodontology and digital dentistry. More than 1,500 employees at 26 locations worldwide are driven by their expertise and passion for the dental market and embody what the name Heraeus Kulzer stands for: service, quality and innovation. Heraeus Kulzer has been part of the Japanese Mitsui Chemicals Group since July 2013. Mitsui Chemicals, Inc. (MCI) is based in Tokyo, and has 137 affiliates with more than 14,300 employees in 27 countries worldwide. Its innovative, practical chemical products are as much in demand in the automotive, electronics and packaging industries as they are in other fields such as environmental protection and healthcare. The preceding material was provided by the manufacturer. Statements and opinions are solely those of the manufacturer and not of the editors, publisher, or the Editorial Board of Inside Dental Technology. THANK YOU TO OUR SPONSOR: HERAEUS KULZER PERFECT FIT. PERFECT SMILE. IN JUST 3 VISITS. CLICK HERE to Become A Lab Partner Today!
Additional Resources LEARN MORE ABOUT THE REVOLUTIONARY DENTURE PROCESS WATCH PALA DIGITAL DENTURES SOLUTIONS VIDEO VIEW THE IMPRESSION MANUAL