Do you like surprises? You may ask–“What kind of surprises?” Well, imagine that you have booked the whole afternoon for one of your patients who came today for the final insertion of 10 maxillary restorations. The case just arrived from your laboratory and you did not have enough time to look at it and you are not quite sure what to expect because every time something comes from the lab it is a true surprise! You slowly start approaching the surprise box and half way through you get a brilliant idea, and ask your assistant to have a look at it first – like this would change anything! She opens the box looks at the case and says, “It looks good!”
You start trying the case in and a cold and then hot sensation passes through your body because you notice that the whole case has a severe canting, as well as there is something odd in the shape of the restorations. If that is not enough, two of the veneers do not fit. Surly the case is’ No Go’. How did this happen?
One month ago your patient made a decision to invest in her smile and, attracted by the big sign above your office stating “General and Cosmetic Dentistry” as well as her long time patronage of your office, she has chosen you to enhance her smile. The final impressions and a c/o bite registration were taken and sent to the lab with a prescription stating ” please fabricate all ceramic restorations for teeth 1.5-2.5. Shade A1″. At the lab all of the information was put together to fabricate 10 all ceramic restorations and sent back to the office in the “surprise box.”
Cosmetic dentistry is an area of practice that combines the skills of the dentist, dental technician and all the auxilliaries of the practice. Like good operative dental practices, consistently good results come from consistently good record taking (Fig. 1), diagnosis and treatment planning. What arrives from the lab should not be a ‘surprise box’; the team needs to have a high degree of confidence about what is inside so that the delivery appointment runs as smoothly as possible. It should contain exactly what is required to bring the treatment phase to a successful conclusion. This is only possible with good communication.
In order to ensure predictable results, a common protocol in the form of checklists must be created.
That protocol has to have established, open channels of communication by means of verbal dialog, written notes (Fig. 6) as well as visual and mechanical aids between the patient, dentist and the laboratory or better yet, the technician working on the case.
Checklist #1: Preoperative Records
Polyvinyl impression of the arch to be treated
Alginate impression or model of the opposing arch
Leveled transfer bow record
Stick bite and c/o bite registration
quality slides, photographs or digital images of existing dentition (Figs. 2-5, 9) with matching shade tabs beside them.
A polyvinyl impression is a better material choice for the preoperative model of the arch to be treated because it will allow the technician to fabricate a very accurate diagnostic wax up and therefore a very accurate and longer lasting set of provisional restorations will be achieved. It is at this stage that a blueprint of the final case is created. The horizontally leveled transfer bow record is essential as well as a stick bite aligned with the interpupilary line (Fig. 4). If using digital photography a SLR type digital camera should be used. All images must have excellent exposure in order to be useful.
Checklist #2: Laboratory fabrication of diagnostic wax-up
Pour and trim base of the models
Articulate models using face bow registration
Design preparations that will best suite the porcelain to achieve desired outcome.
Make a duplicate of the prepared model.
Fabricate the diagnostic wax-up.
Create a silicone stent for fabrication of provisionals.
Fabricate a labial and lingual reduction matrixes.
The base of the models should be trimmed in such a fashion that after mounting on the articulator it is level with the horizon (Figs. 7 & 8).
Design of the preparations at this time can be a very helpful tool for the clinician to illustrate the best preparation design that will support the restorations.
When fabricating the diagnostic wax up it is essential at this time for the technician to know the patient’s chief complaints and expectations of the treatment.
Reduction matrixes should be carefully used by the clinician to not only provide enough reduction, but to also make reduction uniform and suitable for application of special effects (Figs. 10 & 11).
Checklist #3: Final Records
Polyvinyl impression of the treated arch.
Polyvinyl impression of the opposing arch.
Leveled face bow record.
Stick bite and c/o bite registration.
Quality slides, photographs or digital images of the preparations with the matching shade tabs beside them as well as finished and approved prototypes.
Silicone matrix of the prototypes recorded in the patient’s mouth.
Model or impression of the approved prototypes with images and notes.
Polyvinyl impression of the opposing dentition is a better material choice to accommodate bite registration, which is usually extremely detailed and not quite compatible with model poured of an alginate impression.
Theoretically leveled face bow record should not be necessary as it was already taken in the preoperative stage, providing of course that the opposing dentition record was recorded in polyvinyl impression material and no adjustments to the opposing dentition were made in between appointments.
Checklist #4: Laboratory fabrication of final restorations
Fabricate working models.
Articulate models in a similar fashion as in the preoperative stage utilizing all of the newly received records.
Mount prototype model and fabricate an incisal matrix.
Schedule between three and nine units of porcelain per day based on quality expectations.
Maintain an open channel of communication between you and the clinician utilizing SLR digital photography.
When fabricating working models and separating the dies, make sure to cut them parallel to the patients midline as this will take care of any canting problems you might struggle with. The incisal matrix will be your guide not only to correctly replicate the length and positioning of the prototypes, but also to help you with the placement of internal effects.
A bio-esthetic restoration has many details that alone can seem quite insignificant, but when combined make a huge difference. This not only requires extra time at the porcelain stage, but at every single step prior to that in the laboratory as well as in the chair (Fig. 12).
PLAYING THE GAME
First things first. You must learn the game well. Take advantage of the many learning opportunities available today, as the ‘trial and error’ method of play in this game is very expensive. For a player to make it to the play-offs takes extraordinary skill, but it takes months of practicing with the team to win the play-offs!
A winning team reaches their peak by practicing on a daily basis and regardless of whether it is the play-offs or just a practice game; the coach is always there to ensure that the players’ egos do not cause them to forget about the fundamentals of the game.
This same analogy applies to cosmetic dentistry. All of the dental team members play on the same team, where the protocol is the coach who reminds us of the basic steps to success in treating patients and creating functional bio-esthetic results based on a comprehensive restorative treatment plan.
Marek K. Bedynski, RDT, is owner and operator of FX Veneers Dental Laboratory, Inc., Toronto, ON. He is a Sustaining member of American Academy of Cosmetic Dentistry. Dentistry by Sandra M. Finch, DMD, White Rock, BC.
Oral Health welcomes this original article.
