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A New Generation of Denture Teeth: The Perfect Route to Esthetic and Functional Dentures
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OVERVIEW With a growing awareness of advances in esthetic dentistry, today's patients are ever more discerning about the cosmetic quality of their restorations. This includes the prefabricated teeth incorporated into removable dentures. Given the cost of these full-arch restorations – particularly when implant-retained – patients expect a satisfying solution. In this article, Thorsten Michel, MDT, provides insight into the development process that led to the creation of Ivoclar Vivadent's SR Phonares ® line of denture teeth.
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Thorsten Michel, MDT
Dental Laboratory Owner
Schorndorf, Germany
info@michel-zahntechnik.de |
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| Thorsten Michel completed his dental technician training in 1991 at Mangold dental lab in Stuttgart, Germany, during which time he was awarded the prestigious Gysi Prize. After a stint in the German armed forces, Thorsten worked for Albrecht Schenk dental lab in Schwäbisch Gmünd from 1992 to 1994,
and then Winnenden-based Jürgen Dieterich until 1998. In 2000, he completed master dental technician school in Freiburg/Breisgau, earning best performance in the examination for the master craftsman's diploma. In 2001, he received the Klaus Kanter award. He currently runs his own dental lab in Schorndorf, which he started in June 2000. |
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Frank Lauciello, DDS
Clinical Associate Professor, Restorative Department, SUNY
Buffalo, NY
frank.lauciello@ivoclarvivadent.com |
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| Dr. Frank Lauciello graduated from SUNY at Buffalo School of Dental Medicine in 1969 and completed his prosthodontic training at Buffalo VA Medical Center. Currently a clinical associate professor in the restorative department at SUNY at Buffalo, he was director of the Veterans Administration advanced
program in prosthodontics from 1973 to 1998 and chief of the dental service from 1996 to 1998. He is also director of removable prosthodontics for Ivoclar Vivadent and director of its Implant Esthetics Center of Excellence in Sarasota, Fla. A Diplomate of the American Board of Prosthodontics, he has authored numerous articles and textbook chapters and is actively involved in dental research and product development. |
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Introduction
When fabricating removable dentures, finding suitable anterior teeth that provide the superior esthetics very discerning patients demand can prove challenging. To meet the requirements of an individual case, prefabricated denture teeth must very often be modified to incorporate age- and indication-related characteristics. This challenge led me to look for a solution to this problem. The purpose of this article is to summarize my experience with, and provide insight into, the development process that led to the creation of SR Phonares® denture teeth from Ivoclar Vivadent.
Discussion
Starting the process involved modeling upper and lower tooth molds that were a reflection of their natural counterparts. These molds featured all the special characteristics missing from existing prefabricated denture teeth (Fig. 1, Fig. 2). It is the first impression, the overall esthetic appearance that is conveyed in the first few seconds in which a tooth is viewed, that counts. These first few seconds are of crucial importance because this is the time it takes someone to decide whether the tooth lives up to his or her expectations. In order to achieve a natural esthetic outcome, lifelike tooth molds with facial and palatal surfaces that feature a truly anatomical design and impart an impression of natural dentition are essential (Fig. 3, Fig. 4, Fig. 5, Fig. 6).
The objective in modeling esthetic tooth molds is to achieve a vibrant but not overly exaggerated facial texture and a practical palatal and lingual design, which supports clear speech and phonetics rather than hampering it. In addition, anterior teeth that have a harmonious, layereddesign and selectively incorporated opalescent and translucent areas, which impart a lifelike appearance, are preferred (Fig. 7, Fig. 8).
Another important aspect is to have a comprehensive range of molds from which to choose. To meet this requirement, I incorporated several tooth characteristics that can also be found in nature.
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This led to the development of age-related tooth molds, which take into account the needs of patients at different stages in life. This allows for the selection of tooth molds based on an individual patient's age.
There are three simple steps for choosing suitable tooth molds. First, the basic shape is selected, based on whether the teeth should have a more youthful or distinctive look. Then the desired degree of wear is chosen. In this respect, both the incisal and facial curvature are of importance. While teeth with more rounded incisal edges and a pronounced facial curvature are designed for use in young patients (Fig. 9), those with more heavily abraded incisal edges and a flatter facial curvature are suitable for patients in the more advanced age group (Fig. 10). These features are based on the natural aging process that occurs in the oral cavity over time. In the third and last step, the size or dimension of each tooth is determined using a diagnostic cast of the case. For this purpose, the teeth are classified into "small," "medium" and "large" categories. Tooth molds for smaller and larger alveolar ridges are available.
In a time when the focus is on esthetic dentistry, removable dentures should provide optimum "white esthetics" (Fig. 11). This is especially true for implant-borne removable dentures because all parties involved (i.e., the patient, clinician and dental lab technician) place high expectations on the esthetic outcome and function of this complex and expensive type of restoration.
In order to achieve ideal "white esthetics," the interproximal contours of anterior teeth should allow for the teeth to be lined up very closely without creating the impression of a "white wall." The proximal "Set & Fit" design of SR Phonares denture teeth allows teeth to be set up in diverse positions, without producing open gingival embrasures, or "black triangles," that then need to be filled with denture base material. Even when dealing with highly rotated teeth, a natural-looking tooth setup can be accomplished (Fig. 12).
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Creating a soft transition between the clinical crown and the tooth neck section optimizes the esthetics, as it facilitates modeling of the gingival contours. Placing a wax layer that tapers toward the cervical portion of the clinical crown creates the impression of naturally grown gingival tissue.
To effectively cover a frame and implant abutments, a cervical design that accommodates implant abutments with an emergence profile of approximately 5 mm in diameter was also created. In most cases, no adjustments with tooth-colored material are required in the proximal anterior regions.
In addition to their advanced anterior tooth design, SR Phonares denture teeth are characterized by extraordinarily high wear resistance, thanks to their Nano Hybrid Composite (NHC) material composition. Due to the fact that implants are firmly anchored to the alveolar bone, materials of extremely high strength are required in the fabrication of implant-borne removable dentures. As these dentures are not supported by soft tissue, masticatory forces are transferred completely to the materials used in the restorative process, which exposes them to very high levels of stress. SR Phonares NHC anterior tooth molds are not exclusively indicated for implant-borne dentures, however. They are perfectly suited for complete and partial denture prosthetics.
Conclusion
Ivoclar Vivadent's SR Phonares denture teeth closely replicate the shape and surface texture of natural dentition. The teeth feature a harmonious four-layer design and exhibit natural opalescence and fluorescence. Their new NHC material has been proven to provide high durability and excellent resistance to wear and plaque accretion. SR Phonares denture teeth also feature a well-balanced labial and palatal design. Due to their specially designed interdental closures, a natural-looking appearance of the denture can be achieved with ease. These denture teeth allow the dental technician to achieve precise, high-quality results with minimal effort or difficulty.
SR Phonares Denture Teeth Q&A
Courtesy of Dr. Frank Lauciello, Ivoclar Vivadent
Q: Why did Ivoclar develop SR Phonares denture teeth?
A: SR Phonares NHC denture teeth were developed in response to market demands for higher esthetics and wear resistance in complete, partial and implant-retained denture prostheses.
Q: What are the benefits of a composite tooth?
A: Ivoclar Vivadent spent several years developing its Nano Hybrid Composite, a unique material that yields true-to-nature esthetics and increased wear resistance over conventional resin materials. This new technology provides the opportunity for clinicians and technologists to prescribe and create truly esthetic removable restorations with long-term results.
Q: How were the molds developed?
A: Like the NHC material, the SR Phonares anterior molds were a new development. Each mold was artfully designed to express individual patient characteristics ("soft" or "bold") and age ("youthful," "universal" or "mature").
Q: How does this new generation of Nano Hybrid Composite bond to resin denture base materials?
A: The unique properties of the NHC material yield good bonding results. The NHC material has inclusions of PMMA (polymethylmethacrylate) material that promotes bond strength and durability. The highest bond strengths have been recorded when processed with the SR Ivocap Injection System.
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