Written by Christopher J. Stevens, DDS Wednesday, 14 November 2012 14:29
The ability to change lives through comprehensive care is truly a wonderful part of dentistry. But along with the advantage to the patient, there is a challenge to the providers to understand and address the chief concerns and desires of the patient, as well as to understand all the medical and dental implications related to treatment.
Two other considerations need to be made with regard to full-arch or full-mouth comprehensive care: Will the care being considered be tolerated and accepted physiologically? Can the desired treatment be provided within the financial constraints that many patients are presenting with in the current economic times?
There can be many issues regarding the patient’s ability to tolerate and accept the intended care. What will be the restorative material choice? What is the health of the stomatognathic system? Is this a case that requires a change in the patient’s existing vertical dimension of occlusion (VDO)? If the bite needs to be opened, how much is enough? How does one know if it is too much or too little? Can a trial bite position be done? How can a trial bite position be transferred to the final bite records? Not answering these questions can result in providing “hope dentistry,” a situation when the clinician simply hopes that everything turns out for the best.
Further complicating the case is the increasing desire by patients to spread their care out over time, sometimes a year or more. Of course, when providing full-arch or full-mouth care in a case requiring that we open the bite, traditional quadrant dentistry is not applicable. Therefore, new methods must be devised to create holding patterns until the next phase of care can be started.
The case presented here will illustrate a method to satisfy both concerns discussed above. By using these techniques, providers can eliminate “hope dentistry” and be sensitive to their patients’ financial situation.
A 56-year-old male was referred to my practice by a good friend and colleague who had been diagnosed with cancer. The patient’s restorative work had been planned for some time, but due to scheduling issues on the part of the patient and the health of his doctor, his care had been delayed. By the time the patient was completely ready, the doctor’s health had declined to a point where he was no longer practicing.
The patient’s dental history consisted of traditional dentistry with several large amalgam restorations and PFM crowns. He was concerned about wearing his teeth away, and also about crowns that had broken due to bruxism (Figures 1 to 4). Because of discussions with his previous dentist, the patient was very knowledgeable about his condition. He asked that he have his teeth “rebuilt” to give him more vertical support, which he hoped would help him reduce his grinding. In fact, he wore a maxillary and mandibular appliance simultaneously at night. He said that if he wore just one appliance his jaw would hurt in the morning. If he wore both, not only did he not have jaw pain, he slept better. However, he had broken the maxillary appliance into 2 pieces.
|Figure 1. Preoperative view; unretracted frontal smile.||Figure 2. Preoperative view; retracted frontal smile.|
|Figure 3. Preoperative view; maxillary arch.||Figure 4. Preoperative view; mandibular arch.|
The patient was asked to complete a symptomatic history fashioned after the Kinnie-Funt-Stack Visual Index. Symptoms reported included tension headaches, pain in the cheek and neck muscles, and shoulder stiffness. He attributed these symptoms to his nocturnal bruxism. The existing occlusal disease raised my level of concern for the health of his temporomandibular joint (TMJ) complex. In order to evaluate the TMJ complex, bioelectric instrumentation (BioRESEARCH) was utilized. Analysis of joint vibration recordings demonstrated low-level vibrations near maximum opening that were indicative of eminence vibrations (Figure 5). Corrected bilateral multipositional parasagittal tomograms (Figures 6a and 6b) were also obtained. The information from these diagnostic tests demonstrated the patient’s resistance to systemic breakdown, and the decision was made that the TMJ complex did not need to be treated prior to restoration. The information also helped to establish a prognosis: due to the patient’s high resistance to systemic breakdown, even withstanding his occlusal disease, his acceptance of a new occlusal environment should be favorable.
|Figure 5. Joint vibration sweep display (BioRESEARCH). Low-level vibrations on the right side are evident at the wide opening position. This is indicative of an eminence vibration, considered nonpathologic. Opening occurs without deviation or deflection.|
|Figures 6a and 6b. Bilateral temporomandibular joint (TMJ) tomograms, closed view.|
In order to increase the VDO, the 3-dimensional (3-D) relationship of the mandible to the maxilla had to be modified. That relationship was determined via progressive appliance therapy. The appliances used allowed an unimpeded trajectory of closure or a path to develop. A vertical point along that path was then chosen. This position was recorded with a rigid bite registration material (Luxa-Bite [DMG America]) (Figure 7). To determine a preliminary incisal length, a mock-up with flowable composite resin (Revolution Formula 2 [Kerr] was done. Using the phonetic determination of the F- and V-point (Figure 8), the incisal edge length, relative to the lower lip position, was modified until the length satisfied both aesthetic and phonetic considerations.
In addition to the bite registration and incisal edge determination, other records were obtained. These records included the intended modifications to gingival tissue zenith heights and position, midline, shape, and the shade to be used for the provisional restorations.
|Figure 7. Rigid bite registration (Luxa-Bite [DMG America]) recording of the intended occlusal relationship.||Figure 8. Unretracted view of the incisal mock-up. (Note the incisal edge position relative to the lower lip.)|
|Figure 9. Frontal view of mounted pretreatment maxillary cast for comparison of the stick bite to the |
|Figure 10. Frontal view of the completed diagnostic wax-up.|
|Figure 11. The pretreatment bite registration is seated fully against the unprepared teeth and relined to maintain the integrity of the registration throughout the preparation appointment.||Figure 12. Maxillary preparations completed. Tissue retraction was completed with the CO2 laser.|
Quality maxillary and mandibular study impressions were obtained with vinyl polysiloxane (Aquasil Ultra [DENTSPLY Caulk]) and accurate dental casts were then fabricated. The casts, along with the occlusal bite registration, were sent to the dental laboratory team for mounting on an articulator (Accu-Liner [Accu-Liner Products]). The maxillary cast was mounted to the upper member of the articulator using the hamular notch—incisive papilla (HIP) plane. This HIP plane was introduced to dentistry by Dr. Harry Cooperman in 1960 and has been shown to be a very reliable horizontal reference plane of the skull.1,2 The mandibular cast was mounted relative to the maxillary cast utilizing the rigid occlusal bite registration provided. The mandibular cast was then removed from the articulator and the provided stage set in place.
Analysis of the maxillary cast against the stage demonstrated a pitch concern (the anterior region pitched up). This concern would be addressed by increasing the length of the anterior teeth as demonstrated in the mock-up.
A stick-bite reference was taken. It should be noted the stick bite is not a representation of level but rather a representation of perpendicular to plumb. In this way, the smile-line is perpendicular to the long axis of the face, even when the head is tilted. The stick bite is then placed on the mounted maxillary cast and compared to the stage. Note in this case, the stick bite is parallel to the stage of the articulator indicating no presence of an unwanted frontal roll to the smile and/or the maxillary arch (Figure 9).
The central incisor length, as determined by the F- and V-point, was duplicated on the central incisors of the cast and the maxillary cast was lowered so that the intended incisal edge of the centrals contact the stage of the articulator. Next, the maxillary wax-up was completed by the laboratory team to the ideal plane against the stage. Once the maxillary wax-up was completed, the mandibular cast was re-mounted. Then, the wax-up on the lower arch was completed (Figure 10). Finally, temporary stents and reduction guides could be made by the laboratory team for use during the preparation appointment.
At the consultation appointment with the patient, the decision was made to complete the full-mouth restorative work in segments: the maxillary arch first, followed by the mandibular arch at a later date. The primary reason for this was driven by patient financial constraints. However, a significant benefit to segmenting care is that the patient can “test” the new maxillary-mandibular relationship prior to placement of the final restorations. Our intention was to complete the maxillary arch with final restorations and to provide some form of long-term provisionalization on the lower arch to maintain the intended maxillomandibular relationship. Then, when the patient was ready to proceed with the lower arch segment, the new occlusal position would be verified and accepted. As an additional benefit, this second segment would be much simplified because the care would be provided in centric occlusion (CO).
Laser Contouring of the Gingival Tissues and Preparations
The case was now ready for the preparation visit. Laser-assisted tissue recontouring should be performed first. In this case, the contouring was done to place gingival zeniths in the appropriate position for each tooth independently as well as relation to one another. Symmetry is always the ultimate goal. My intention was to have the zenith height of the central incisors level with the zenith height of the canines. The lateral incisors should be 0.5 to 1.0 mm lower. Further, the zenith position of the lateral incisors is in the middle of the long axis of the tooth while the zenith position of the central incisors and canines is slightly distal to the long axis.
|Figure 13. The maxillary provisionals do not interdigitate with the unprepared lower teeth requiring provisionalization of the unprepared lower arch.||Figure 14. Frontal retracted view of the upper and lower provisionals.|
|Figure 15. Maxillary final restorations articulating with the Radica overlays.||Figure 16. Occlusal view of the temporary overlays (Radica [DENTSPLY Ceramco]).|
|Figure 17. Radica segments make placement easier.||Figure 18. Tooth Slooth II crown seaters (Professional Results) securing the position of the veneer for tacking.|
|Figure 19. Securing the Radica segment via light-tacking.||Figure 20. Flowable composite resin can be added to the facial to mask the darker (natural) tooth color.|
The laser that I used here was the Smart US-20D CO2 laser by DEKA Laser Technologies. This laser emits a wavelength of 10,600 nm, thus providing extremely high water absorption characteristics, the major component of soft tissue. The peak power of the laser is as high as 320 W. The UltraSpeed technology allows for shorter emission time and increased tissue relaxation time. This allows one to incise tissue with the speed of a scalpel while sealing blood vessels for a bloodless field, resulting in virtually no trauma to the surrounding tissues. Using the repeat setting at 1.5 W and 50 Hz, along with the perio tip insert on the laser handpiece, an outline of the intended position could be drawn with guidance from the horizontal stick reference. Once the outline was confirmed, a 2.0 W and 80 Hz setting with the perio tip insert was used to make the gingival changes, again confirming zenith heights and positions were at the pretreatment intention.
Actual tooth preparation could now begin. Teeth Nos. 3 to 6 and 11 to 14 were fully prepared. The previously taken occlusal bite registration was reintroduced, and once complete seating of the unprepared teeth was confirmed, the registration was relined (Luxa-Bite) to maintain the integrity of the occlusal registration (Figure 11). Preparation of the remaining maxillary teeth was then completed. All preparations were prepared with shoulder margins (Figure 12). The posterior teeth would be restored with lithium disilicate restorations (IPS e.max [Ivoclar Vivadent]), and the anterior teeth with leucite-reinforced porcelain restorations (IPS Empress [Ivoclar Vivadent]).
The color mapping, smile selection, and natural core preparation shades (also referred to as dentin-stump shades) with necessary photographs were obtained. A stick-bite reference (perpendicular to plumb) was made. This allowed the dental laboratory team to compare horizontal to the stage of the Accu-Liner articulator, removing the potential for canting in the final restorations.
Provisionals were fabricated by loading a bis-acryl temporary material (Integrity [DENTSPLY Caulk]) into silicone stents (Sil-Tech (Ivoclar Vivadent]) fabricated from a model of the diagnostic wax-up. The maxillary stent was loaded and seated against the maxillary preparations. An attempt was made to place even pressure throughout the stent using the palate and tuberosities as positive stops. Rubbing the anterior portion of the stent with a finger helped to thin excess, making it easier to remove. The silicone stent was removed 2 minutes after placement, then the excess bis-acryl material was removed with a No. 15 scalpel and fine carbide burs.
The maxillary provisionals do not interdigitate with the unprepared lower teeth (Figure 13); therefore, even though the lower arch was unprepared at this time, provisionalization was required. To accomplish this, soft periphery wax was placed in all gingival embrasures. This was done to reduce the amount of interproximal cleanup needed due to potential excess of the bis-acryl temporary material. The lower silicone stent was then seated over the unprepared teeth in similar fashion as the upper arch. The mechanically retained provisionals over the lower teeth were then trimmed and polished (Figure 14).
A next-day, follow-up appointment was made to evaluate incisal edge position, shape, and color. Occlusal adjustments were performed as necessary. Any modifications made at this time were related to the laboratory team. Photographs and/or casts of the provisionals can be included with instructions to the lab team.
Maintaining tissue health, to minimize gingival bleeding at the seat appointment, is vital to the bonding process. Carefully opening gingival embrasures will allow for daily flossing (I recommend Super Floss [Oral-B]). In addition, daily water irrigation (Waterpik [Waterpik]) with a solution of water, LISTERINE (Johnson & Johnson), and antibacterial hand soap promote healing and reduce bacterial activity.3
The case was sent to the lab team with all the gathered records. In order to maintain an engineered occlusion, the maxillary arch restorations were fabricated to a level occlusal plane aided by the stage of the Accu-Liner articulator.
Modifications to the lower arch needed to be made even though those teeth were not prepared. This process required the teeth be overlayed with a transitional material strong enough to resist fracture, but one that could also be engineered for occlusal maintenance of the intended maxilla-mandibular relationship. The material of choice in this case was a glass-filled composite provisional and diagnostic material (Radica [DENTSPLY Ceramco]).
Radica is a UDMA-based visible light-cured composite with an MMA-free resin matrix. This material is dimensionally stable, providing a good long-term option for provisionals.
The Radica overlays were fabricated against the maxillary final restorations (Figure 15). My preference is to fabricate these in 3 “segments” because this simplifies the adhesive process; this includes the right and left posterior segments and the anterior segment (Figures 16 and 17).
At the cementation appointment, following the administration of lingual local anesthesia, the maxillary provisionals were sectioned and then removed. The preparations were cleaned with Consepsis Scrub (Ultradent Products) and an intracoronal brush (ICB [Ultradent Products]) followed by Consepsis (Ultradent Products) liquid. Each unit was tried independently for fit and, as a group, for proximal contact determination. Once confirmation of each unit was accomplished, the anterior segment was placed and reviewed for midline position, canting, shape, and shade. Incisal edge length can be evaluated by comparing it to the length of a remnant of the adjacent central provisional restoration.
Once the patient had accepted the restorations, they were removed and thoroughly rinsed. The lithium disilicate restorations were to be seated using a universal composite resin cement (Multilink Automix [Ivoclar Vivadent]). The anterior leucite-reinforced porcelain restorations were to be cemented into place with a light-cured resin cement (Rely X Veneer [3M ESPE]). Both the anterior leucite-reinforced porcelain restorations and posterior lithium disilicate restorations had been previously etched with hydrofluoric acid in the dental laboratory. Silane primer (Kerr) was to be applied at the chair to the restorations before cementation. For the anterior teeth, after light-cured resin cement was applied to the internal aspects, they were placed in a crown and bridge light-protected organizer (C & B Organizer [Patterson Dental]) to maintain a light free environment and to log their respective position in the arch.
The rubber dam (Derma Dam [Ultradent Products]) was placed in a trough format and the palate was sealed with bite registration material to prevent saliva contamination. The 6 anterior teeth were etched for 15 seconds and washed. Excess water was removed and Ultracid (Ultradent Products) was placed as a wetting agent. A bonding adhesive (OptiBond Solo Plus [Kerr]) was applied per manufacturer instructions. The units were the placed short of final position starting with the 2 central incisors. The remaining restorations were placed front to back. Final positioning was done with 2 Tooth Slooth II crown seaters (Professional Results); one positioned incisally, pushing apically; and one positioned facially, pushing lingually. When completely placed, the units were tacked midfacially (Figure 18). Once tacked, complete seating of the restorations was confirmed. Final curing was performed with multiple light units to expedite the curing process. Remaining bonding resin was removed with a scalpel (No. 12 blade), fine carbide finishing burs, and diamond impregnated finishing strips. The rubber dam was removed.
To seat the Radica on the lower arch, the rubber dam was again employed. A total-etch technique with dual-cure resin cement was used to ensure a complete seal. The Radica segment was loaded with resin cement and held to place while initial cleanup was done with a rubber tip stimulator (Sunstar Americas). The segment was then tacked to place (Figure 19). Final cleanup was accomplished with finishing diamonds. Flowable resin can be added to create color blending and mask the facial aspect of darker natural teeth (Figure 20).
Some authors prefer to prepare all the teeth and use long-term provisionals over prepared teeth to discover a final restorative position. The Radica overlay method allows use of an engineered occlusion, a fracture resistant and durable material and a complete adhesive protocol to prevent leakage, especially in the prepared dentin.
Once the mandibular arch was seated, preliminary occlusal adjustments were performed. Since the patient’s occlusal awareness was reduced by the effects of the anesthesia, adjustments were done only to remove obvious CO prematurities. Final adjustments were done the next day.
LOWER FINAL RESTORATIONS
About one year later, the patient returned to the office ready to proceed with the final restorations on the lower arch. Joint vibration analysis was again performed to evaluate the TMJ’s acceptance of the new occlusal position. Recordings demonstrated no evidence of joint noise. Normal mandibular range of motion without deviation or deflection was also noted (Figure 21). Tomograms at CO were also favorable (Figures 22a and 22b). The patient also reported he no longer had jaw pain.
|Figure 21. Joint vibration sweep display, demonstrating the absence of any joint vibration and opening without deviation/deflection.|
|Figures 22a and 22b. Bilateral TMJ tomograms at new centric occlusion.|
A CO registration was used with the same rigid bite registration material as described above. Preparations on teeth Nos. 19 to 22 and 27 to 30 were completed. It was noted that the retention of the Radica to the occlusal portion of the teeth during preparation was an indicator of the adhesive nature of the overlay (Figure 23). Once the initial teeth were prepared, the bite registration was reseated and relined in the prepared areas maintaining the occlusal registration. The remaining 6 teeth were prepared, and the bite registration was relined again in those areas.
Impressions were obtained using digital impression technology (iTero [Cadent]). Provisionals were fabricated using the technique described earlier. All records and instructions were sent to the dental laboratory team.
Once the final restorations were completed, the patient was appointed for placement in the same manner as described earlier. Again, only preliminary occlusal adjustments were performed. Since the patient’s occlusal awareness was reduced by the effects of the anesthesia, final adjustments were done the next day.
The patient returned to the office for the removal of any residual bonding resin and the initiation of occlusal balancing. Balancing was accomplished by utilizing the T-Scan III System (TekScan). This system accurately records the timing of occlusal contacts and the forces generated by them.
The T-Scan III occlusal analysis system measures occlusal contact in real time and has the ability to disclose time and force data. Occlusal data is recorded by instructing the patient to occlude on an intraoral sensor that is connected to a computer. This time and force measurement capability allows the clinician to optimize occlusal contact patterns precisely, thereby attaining measurable verification of what has been theorized as ideal occlusal parameters in many classical occlusal principles.4-7 The data displayed on the monitor represents the maxillary arch. Data can be displayed in various formats including the 2-dimensional (2-D) contour view and the 3-D columnar view. The 2-D view resembles articulation paper marks and the 3-D view makes force viewing easy when compared to the color-coded force legend. The force versus time graph allows the clinician to view time between initial tooth contact and last tooth contact; ideally less than 0.2 seconds.8
|Figure 23. Note the adhesive retention of the Radica material even during preparation for the final restorations.||Figure 24. Right to left force balancing noted as 52.9% right and 47.1% left on T-Scan III occlusal management system.|
|Figure 25. Frontal view of the final restorations.|
The display generated by the T-Scan demonstrated a force balancing right to left of 52.9% to 47.1% (Figure 24). Our ultimate goal is 50 to 50 with an acceptable range 45 to 55. The time between initial tooth contact and static intercuspation was 0.162 seconds, again within the acceptable range.
Follow-up appointments were made for final touch-ups and fabrication of a nocturnal parafunctional appliance (bite splint). The patient was extremely pleased with the final results (Figure 25). Thus far, the 2-year postoperative appointment demonstrated excellent stability of the restorations and no evidence of jaw discomfort.
Discretionary income of our patients has been reduced in recent years. Comprehensive care, although still a needed option, is often being delayed. A segmental approach to care, in a manner that allows the patient and practitioner to achieve goals over time, can be very valuable. Not only can it help a patient achieve a desired outcome; this approach allows the doctor to know the care provided will be accepted and well-tolerated by the patient.F
The author wishes to thank Kent Garrick of Arrowhead Dental Laboratory (Sandy, Utah) for his help in development of this protocol. His ability to listen to my thoughts and ideas and then apply laboratory solutions to them was critical to the success of this technique. The author also wishes to thank Arrowhead Dental Laboratory for these fine restorations. Dr. Michael Forgette, first my student, then my friend, and finally my inspiration, lost his battle with cancer. I truly wish that he was able to know how many people have been helped with this approach to care.
- Cooperman HN, Willard SB. Studies of the Louchheim Collection of Skulls. New York, NY: American Museum of Natural History; 1960.
- Cooperman HN. HIP plane of occlusion in oral diagnosis. Dent Surv. 1975;51:60-62.
- Venneri AJ. A new approach to at-home oral irrigation. J Am Dent Assoc. 1997;128:755.
- Kerstein RB. Current applications of computerized occlusal analysis in dental medicine. Gen Dent. 2001;49:521-530.
- Dawson PE. Evaluation, Diagnosis and Treatment of Occlusal Problems. 2nd ed. St. Louis, MO: Mosby; 1988.
- Schuyler CL. Fundamental principles in the correction of occlusal disharmony, natural and artificial. J Am Dent Assoc. 1935;22:1193-1202.
- Glickman I. Clinical Periodontology. 4th ed. Philadelphia, PA: W.B. Saunders; 1972.
- Kerstein RB, Grundset K. Obtaining measurable bilateral simultaneous occlusal contacts with computer-analyzed and guided occlusal adjustments. Quintessence Int. 2001;32:7-18.
Disclosure: Dr. Stevens lectures for TekScan, Inc, BioResearch, Inc, and DEKA Laser Technologies, Inc.
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