James Fondriest, DDS
Sophisticated patients want their dental concerns treated without appearing as if they have been restored. This case presentation describes the planning and treatment steps for the re-creation of an aesthetic smile. The patient had dento-facialasymmetries and an elevated occlusal risk of fracture due to bruxism. Lithium disilicate glass ceramic in a pressed version with stacked veneering porcelain was selected as an ideal restorative material for natural aesthetics and to fulfill the strength requirements for the maxillary anterior restorations.
This article discusses the use of collaborative treatment planning method in order to provide aesthetic improvement for facial asymmetries in high-stress areas. Upon completing this article, the reader should:
- Understand the communication protocols involved in including both the patient and the laboratory technician in the entire treatment planning and restorative phase.
- Be aware of the role of strength requirements when treating patients with proven bruxism and destructive wear patterns.
Successful delivery of indirect restorations is predicated upon a concise understanding of the patient’s existing facial architecture, his or her restorative needs and desires, and thorough communication with the laboratory. Particularly when restoring patients with dentofacial asymmetries, care must be taken to carefully determine where to create proper angulation and integration in order to develop a natural-looking result. The following case presentation details the steps required to facilitate thorough documentation, treatment planning, and communication with the technician in the treatment of a patient with asymmetrical features.
A 52-year-old female patient presented following a history of having significant dentistry previously performed. Every tooth had a full-coverage restoration or large intracoronal restorations fabricated from numerous materials. The existing porcelain-fused-to-metal (PFM) restorations on teeth #6 through #9, and #13 through #15 were opaque and unnatural in shape, texture and appearance (Figures 1 and 2). The dentition without full-coverage prostheses had restorations that were chipped and leaking, and these teeth displayed different colorations. The axial inclinations of the maxillary central incisors pointed towards the patient’s right hip. The left maxillary teeth had super-erupted and were hanging lower than the occlusal table. They had super-erupted to make occlusal contact when dentistry had been performed on the mandibular left many years earlier. There was a mild reverse smile line. Much of the dentistry that had been previously performed was a result of fracture to the natural teeth or the large restorations. The wear that was created on the existing 16-month-old nightguard suggested that the patient was a heavy bruxer.
The patient desired improved symmetry within her smile and improved exposure of the uneven gingival tissue in order to provide a more homogenous and natural appearance to her teeth. The patient wanted to be involved in the treatment decisions; because she felt that the mandibular teeth did not display in her smile, she desired to limit treatment to the maxillary arch. She had previously been restored in many small “installments” by several dentists with no comprehensive planning toward a final, pleasingly aesthetic result. Overall, she desired this result.
To even the gingival height discrepancies and to reduce the gingival display, crown lengthening was planned for teeth #6 and #7, and #11 through #13 (Figure 3). Tooth #14 was a pontic. A surgical template which indicated the desired post-surgical tissue heights was constructed and delivered to the periodontist.1-3
Ten weeks subsequent to the perio-plastic surgery to align and provide symmetry to the gingival scallops, new records were taken and a trial equilibration was performed on stone models of the patient’s mouth articulated in maximum intercuspation.4 This trial run was performed to evaluate how much tooth contour would have to be removed to create an aesthetic appearance and less abusive anterior guidance (Figure 4).
This was the reductive part of the planning phase. It was determined from this exercise that a flatter occlusal plane could be created without exposing the metal substructure of the anterior mandibular PFM bridge. The patient was informed of the possibility of pulpal exposures of the maxillary left teeth when the occlusal plane was raised to the planned level. The vertical dimension of occlusion was maintained because the entire maxillary arch was not being treated.5 The clenching, bruxing and existing occlusal scheme had caused the musculature to be guarded and spastic. Because significant occlusal modifications were planned for one or both arches and because of the lack of absolute surety of her hinge axis,6-8 a new night appliance was constructed to relax the musculature prior to the actual equilibration.
The occlusal equilibration provided the patient with equal-intensity, non-deflective vertical occlusal stops around the arch while hinged in centric relation.9-11 An anterior guidance was created so that immediate disclusion of the posterior teeth in excursive movements occurred. All excursive movements from centric relation, including the tooth-to-tooth transitions in cross-over, were smoothed. Due to the history of destructive bruxism, the guidance was shallowed to reduce the forces on the teeth and future restorations.12,13 The significant enameloplasty and porcelain removal performed on teeth #11 through #15 and #22 through #27 did not cause sensitivity or discomfort. The patient expressed delight with the increased freedom and ease of lateral movement that the equilibration provided.
A porcelain-fused-to-gold restorative was selected for the maxillary left posterior region to fulfill the need for strength due to the bruxism with positive wear characteristics. This segment was finished before the anterior teeth. Pursuant to the patient’s agenda, all-ceramic crowns were planned for the maxillary anterior teeth. The high chroma and heterogeneous coloration of the prepared teeth required porcelain with significant masking ability (Figure 10). A high-strength lithium di-silicate glass ceramic (IPS e. max Press, Ivoclar Vivadent, Amherst, NY) with a stacked veneering porcelain (IPS e. max Ceram, Ivoclar Vivadent, Amherst, NY) was chosen as an appropriate material for this case.21 Final preparation of the maxillary anterior teeth was performed, avoiding sharp transitions, inner angles, and feather edges.
Although the underlying color was different than the final shade desired by the patient, sufficient restorative material thickness was available to allow the use of a high translucency ingot, limiting the need for layering to the incisal third. The full contour waxup was, therefore, cut into the shape of the dentin lobes that would exist in natural teeth in the incisal third of the restorations and left at full contour in the gingival two thirds prior to investment (Figures 11 and 12). Contour and surface morphology were finalized in the unlayered gingival portions of the restorations. Shading ceramics were applied prior to re-establishing the incisal contour with layered ceramic (Figures 13 through 15). Once full contour was achieved, subtle improvements in surface morphology and contour were placed while following the essence of position, length, width and angulations accomplished by the provisional restorations. The restorations were glazed, polished to an appropriate surface luster, and etched prior to delivery (Figure 16).
There is a strong and growing demand from patients to create symmetry in their dentistry that is divergent from a believably natural appearance. In the case presented herein, the patient presented with significant dento-facial asymmetries and a strong bruxism habit. She had a goal to create a very symmetrical smile. The occlusal risk required high-strength porcelain. Flattening and correcting the occlusal table improved the symmetry issues and allowed for a more desirable and forgiving occlusal scheme.