November 1, 2004
by E. Dwayne Karateew, DDS and Marco Beschizza, MDT
All to often the result of poor dentist-laboratory communication culminates in the “blame game”, whereby each professional points the finger at the other for the lack of desired outcome. The ensuing breakdown of trust and mutual respect has the potential to lead to hasty troubleshooting decisions, punitive alternative outsourcing and ultimately mistrust and severed relationships. This interaction has no place in our day-to-day practice of the art and science of dentistry.
We as dentists and laboratory technicians strive to create an environment within our individual workspaces, which is based upon a solid foundation of the “team” approach. Why would we not consider this intimate and mutually supportive type of relationship between our two disciplines, significant, since we both rely so heavily on one another. This unique inter relationship is dynamic, maturing, and evolving, and should be lauded rather than suppressed. Only by embracing a close relationship and having an unwritten understanding of each others technical limitations can we come close to having the perfect symbiotic relationship.
THE DIAGNOSTIC WAX-UP
This is the perhaps the first opportunity that both the dentist and technician can communicate between themselves in order to establish the technical parameters of the case and relate the patients esthetic demands into a ‘hard’ medium.
With properly mounted study models, assisted by utilization of a facebow, one can properly assess occlusal vertical dimension, mandibular excursive pathways and the form and function of the stomatognathic system. Through verbal and non-verbal communication, it is critical for the dentist to relate to the technician the functional and esthetic end point for the case.
With the assimilation of this preliminary information the technician can then complete a full contour diagnostic wax-up. Often, treatment limitations will be brought out during this process as it gives the technician the opportunity to account for the required restorative materials. Allowances can be made for cast metal thickness of the prosthetic coping, and adequate space required for the layering of the ceramic veneering material. An analysis of individual tooth form, from the gingival margin arch to the position of the incisal edge and the transitional elements between the two must be established as well as subtle characteristics including height of the gingival zenith, gingival and incisal embrasure position, as well as individual depressions and transitional line angles.
Unfortunately, looking at the diagnostic elements on a model, are simply diagnostic elements on a model, and only become fully visualized when surrounded by the other elements that are directly lined to them which will complete the picture. Then and only then do we find out if our interpretations are correct, failed or we observe other elements that are uncomplimentary to the result that we set out to achieve.
Establishment of the determinants of occlusion from cuspal inclination, mesial-distal and buccal-lingual parameters, mutual protection or group function must also be established at this time with direct input from the dental professional. These previous steps are completed with the implicit understanding that this may be changed in accordance to the findings in the utilization of the provisional restoration.
Ultimately, the full contour diagnostic wax-up will perhaps best be utilized when duplicated in wax again and forms the foundation for the cut back prior to investment and casting of the ceramo-metal framework.
It is during the execution of this critical step, the technician has an opportunity to examine the physical limitations of the proposed case and relate them to the dentist, so that together an ideal plan and series of tooth preparations can be established.
TOOLS FOR HEIGHTENED COMMUNICATION
With all the current discussion regarding the quest for the perfect smile, makeovers and the like, communication may not be particularly directed especially in situations where all the visible teeth are being treated. The public demand for esthetic dentistry has markedly increased over the past decade because of the development of new esthetic products, simplified techniques and increased patient-consumer awareness.
The dentists attempt to meet the patient’s needs and provide an acceptable outcome can become a challenging task, depending on the patient’s perception of the need. However, it is an absolute requirement when only one tooth is being restored, or the prosthesis being contemplated leaves several adjacent teeth in the arch untouched. Any tool or piece of equipment from the most basic to the most sophisticated can, and should, be utilized to achieve greater accuracy in the reproduction of the natural state of the dentition.
A basic, hand drawn shade map has in been an excellent method of detailing the subtleties and nuances of the individual characteristics of the tooth. The talent of the dentist/artist to place his/her thoughts on paper through the pencil has limited us. The advantage that this form of communication has is that it often will lead to considerable thought as to what is occurring within the tooth itself.
Perhaps the most basic and universally utilized method of communication is the recording of the required basic shade of the restoration. It is critical to recognize, in advance, the material of choice for the restoration, as this will affect the shading system that will be used. The “Chromoscope” system is a proprietary shading system which is designed to be paired with any of the Ivoclar products such as, but not limited to: Empress, Eris and Concept.
Although Vident has licensed its Vita Classic shade system to many different ceramic systems, its revolutionary Vita 3-D system remains only truly applicable to Vident ceramics. Although many ceramic systems and laboratories claim that they can match the Vita 3-D shades, at best it is guesswork and inter-system matching should be avoided.
We do acknowledge that the ability of the dental practitioner to match colours and shades correctly and consistently is a critical component of restorative dentistry. The ability to match and reproduce shade accurately between the operatory and laboratory may now be controlled with accuracy and certainly greater reproducibility with the use of electronic spectrophometers, clinically recognized as ‘digital shade systems.’
There appears to be great promise of increased standardization in shade taking as the clinician may elect, depending on the model, to create a digital map, generalized whole tooth shade or segregate the shade into thirds. Additionally, laboratories can greatly increase their standardization of production by facilitating an increase in quality assurance by crosschecking the shade of the applied porcelain postproduction with these digital units.
Colour photography has long been a standard within dentistry for the evaluation of patient dentition and the documentation of treatment. Intra-oral cameras (e.g. Accucam) and the Polaroid SLR5 will produce quick photographs of a tooth or the oral environment, but may lack the required detail for adequate transference of information to the technician.
Macro 35mm traditional film cameras are exceptional in recording the information, however, the lag time as a result of developing the slide or print make this information difficult for laboratory to utilize. The recent introduction of digital photography has resulted in an increased acceptance as an effective, essential approach to diagnosis, treatment planning, and restorative procedures.
This communication tool can further enhance multidisciplinary communication between the dentist-technician team, specialists, and various members of the restorative team, which will result in increase patient satisfaction and restorative success. Digital imaging has eliminated the inconsistency traditionally encountered during the attempt to determine the patient’s desires and expectations, as images of anticipated post-operative results can be easily incorporated during the treatmen
t planning phase to determine viable treatment options and arrive at an approach that satisfies the functional-esthetic goals of the team and the expectations of the patient.
The incorporation of digital cameras into clinical dentistry has enabled us to obtain images using real-time shooting modes. Transference of the digital information to the laboratory in the form of a jpeg, tiff file or bitmap is extraordinarily easy through the internet (e-mail) or by being burnt to a CD-ROM which can be included in the lab case pan.
The laboratory can then use the image directly and correlate it to a specific shade tab, or convert the image to a gray scale in Corel Photoshop and from which a determination of the value of the surround teeth can be established. As a result this technology is changing the way we think about the entire photographic process. With its fast and efficient delivery of pictures, digital photography at last fulfills our wish list of dental photography and communication.
Perhaps the most direct for of communication is also the best. If the dental practitioner is fortunate enough to have the technician in the office or within close proximity, then the requisite dialogue can occur directly. The laboratory team member(s) can visualize the problems themselves and formulate the solution with the assistance of the input of the patient and the attending dentist.
Stacking and firing of the porcelains can occur with repeated oral try-ins, to adjust for subtle variances in shape and shade. This three-way relationship (dentist-patient-ceramist) without a doubt produces the most pleasing aesthetic results.
We have explored various avenues to increase the level of communication between the dentist and the laboratory technician. We are fortunate to have at our disposal, a multitude of relatively inexpensive tools that facilitate this dialogue. In the second part of this discussion we will examine the results of this dynamic interaction, with the creation of the “Supernatural” dentition.
Marco Beschizza trained and qualified as a dental technician in England. He attained a special masters Diploma at the Wielemdorf Masters School in Germany in 1989 where he ran a specialized cosmetic laboratory and developed and manufactured the MOONS Ceramic System. He lectures extensively and maintains a laboratory in Vancouver, BC.
Dwayne Karateew obtained his DDS from Columbia University in New York and Diplomas in Periodontics and fixed Prosthodontics from the University of Pennsylvania. He participates as a member on the Faculties of the University of British Columbia, University of Washington, the University of Pennsylvania and Columbia University. He practices in Vancouver, BC. Dr. Karateew is a contributing consultant to Oral Health.
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