TOWNIE CLINICAL: Establishing a Stable Occlusal Platform in a Partially Edentulous Dentition using Z By: Martin B. Goldstein, DMD

Figure 1 presents an anterior retracted pre-operative view of the case to be restored. The absence of molars posterior to 12 and 29 is evident. Jumping ahead in time, we observe in

Figure 2 that those teeth remaining in the mandible have been restored with full coverage ceramic restorations, save for the two cuspids. The issue at hand now involves full coverage restoration of teeth 5, 6, 7, 11 and 12. (Teeth 8, 9, and 10 were slated for direct composite veneering following completion of the full coverage restorations.)

Figure 3 demonstrates full coverage preparations on those teeth to be crowned prior to impression and bite registration.

Figure 4 demonstrates the same teeth with a Glidewell Biotemp temporary splint seated on 5, 6 and 7, but not cemented. The combination of the splint (fabricated from study models and bite registrations following mandibular restoration) and the still intact 8, 9 and 10, were the basis for the desired vertical dimension and occlusal relationship of the opposing arches.

Fabrication of the Initial Bite Positioner

Figure 5 demonstrates the result of having injected a small ribbon of LuxaBite over teeth 8-12, and having the patient close into a pre-rehearsed position. Following initial set, the future “positioner” is removed, allowed to harden for three more minutes and subsequently trimmed in the lab to allow for unimpeded reseating in the mouth. Figure 6 showcases the trimmed Luxabite positioner. Again, the positioner is placed back in the mouth and the patient is allowed to rehearse closure into the bite positioner, first without the presence of the triple tray to follow, and finally with the empty triple tray. During this process the patient becomes familiar with the feel of fully seating his teeth into the proper position and the practitioner can pre-visualize the proper occlusal relationship with the tray in place. Note: It is important that the triple tray can be passively positioned with the dentition not contacting the plastic frame of the tray.

Figure 7 depicts the Luxabite filled tray in place after having been combined with the pre-seated pre-formed bite positioning device, while Figure 8 demonstrates the fused positioner and full bite registration. The positioner is highlighted in red.

Once the Luxabite registration has fully set, it may be taken into one’s lab and relieved of interproximal fins as well as tissue flash that might impede passive seating of models into the registration. This is easily accomplished with a common laboratory acrylic burr.

Prior to dismissing the patient, the accuracy and reproducibility of the Luxabite registration may be confirmed by seating it on the patient’s maxillary teeth and having the patient close repeatedly into the registered position. This is also an excellent opportunity to observe areas of flash that might hinder easy articulation.

Case Completion

As might be observed in Figure 9, an uneventful set of crowns was cemented at the very next visit with minimal occlusal adjusting needed. Teeth 8, 9 and 10 were restored with direct composite veneers at the time of case delivery.

Afterthoughts

It is worth noting that the bite recording obtained in this case was assisted by the presence of a wayward #3 and #19. While out of occlusion, the imprint of these posteriors further assisted the accuracy of the registration by providing additional reference stops with which to position the LuxaBite occlusal platform.

Conclusion

The logic behind an easily placed and easily removed rigid articulating system becomes apparent when considering the enormous time spent adjusting ceramic inaccuracies. Inaccuracies result from articulations based upon bite registrations that are left open to “creative” interpretation as often occurs when using materials that permit deformation.

Dr. Marty Goldstein is a 1977 graduate of the University of Connecticut School of Dental Medicine and practices general dentistry in a group setting in Wolcott, Conn. Marty can be contacted by email at: marty924@cox.net or at his office at 203-879-4649. He is prepared to speak on both digital imaging in dentistry and on the use if high tech methodology to further the cosmetic and restorative practice.