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Written by John H. Tucker, DMD, and Kenneth D. Jones, CDT Saturday, 01 October 2005 00:00
When it comes to comprehensive, full-mouth rehabilitation cases, dentists don't plan to fail, but they may fail to plan. Dedicating time to developing a treatment plan that includes the proper sequence of diagnostic and evaluative tasks—as well as how to utilize them to best achieve the final desired outcomes for the case—can make proceeding with clinical protocol more predictable.
Imperative to the process is recognizing the importance of anterior guidance, incisal edge position, diagnostic models, and suitable treatment modalities that will satisfy patient expectations. Envisioning and determining the final restorations prior to undertaking any preparation design is also essential. The following case presentation details the comprehensive steps taken in a full-mouth rehabilitation that involved a combination of all-ceramic veneers, metal-ceramic crown restorations, and a removable partial denture.
A 62-year-old female presented as a new patient with a chief complaint of the existing crown on tooth No. 28 coming off. In order to establish a trust-based relationship with the patient, the condition for which she presented was addressed first. It has been this clinician's experience that many patients can be lost to the "full-mouth presentation" if they perceive their wants and desires are not heard.
After a discussion with the patient to determine what she wanted in terms of treatment, as well as when she wanted it, she began to "open up" and explain that she really never liked the crowns on her maxillary anterior teeth (ie, shape and color) because, in her opinion, "they looked fake." Similarly, she didn't like the silver hooks on her lower partial denture, which additionally "never did fit well." Finally, she said her lower front teeth looked "worn out."
In describing her dental condition in her own words, the patient explained that she just didn't like the appearance of any of her teeth. Contrary to her original chief complaint, the patient herself was in fact asking for a full-mouth rehabilitation.
|Figure 1. The patient presented with existing ceramometal crowns on teeth Nos. 6 through 11 that were overcontoured and demonstrated dubious margins.||Figure 2. Upon presentation, the lower anterior incisors and cuspids demonstrated wear.|
An examination revealed existing ceramometal crowns on teeth Nos. 6 through 11 that were 10 years old, over-contoured on the lingual aspect, and exhibiting dubious margins. Additionally, these restorations were very opaque (Figure 1). A 30-year-old lower cast chrome cobalt partial denture (ie, Kennedy class II design) was present to replace the missing teeth Nos. 17 through 21 and Nos. 29 through 32. Tooth No. 22 had an existing ceramometal crown with dubious margins and a mismatched shade. Finally, the lower anterior incisors and cuspids exhibited wear (Figure 2).
The patient was reappointed for the additional diagnostics that would enable the development of a comprehensive treatment plan. These included a full-mouth series of radiographs (Kodak film), diagnostic models based on upper and lower impressions (Jeltrate Alginate, DENTSPLY), a Florida Probe for periodontal probing, diagnostic photographs according to American Academy of Cosmetic Dentistry guidelines (Canon G5 digital intraoral camera), a face-bow transfer (Artex face-bow for Artex articulator, Jensen Industries), and centric relation bite registration (Virtual VPS fast set putty, Ivoclar Vivadent) according to Dr. Peter Dawson's bimanual manipulation.
Tooth No. 28 was determined to be nonrestorable. Extraction followed by a bone graft for bone preservation was indicated. Puros graft material (Zimmer Dental) would be used.
The lower incisal edge position and contour would first be determined using a diagnostic wax-up. As wear occurs, the youthful appearance of the concave lingual contour and flat labial contour changes. The concavity turns into a straight contour on the lingual surface, while the labial surface becomes more convex, eventually leading to both surfaces being more rounded, with dentinal cupping.
A prototype incisal edge position would be determined in the mouth using phonetics as determinants. A direct composite resin (4 Seasons, Ivoclar Vivadent) would be used for this purpose.
According to Dr. Dawson, "Lower incisal edge position is critical to aesthetics, phonetics, the occlusal plane, the function of the anterior guidance, and to stability. The lower incisal edges, when viewed together, form the incisal plane. The relationship of this plane is critical to phonetics, because in making the S sounds, air must be constricted between all the incisal edges of the lower teeth and the upper lingual surfaces at the position which is used for the S sound. That position varies from near contact against the lingual surfaces to near edge-to-edge contact. If the S sound is made at an overlap position, the lower incisal plane is more apt to have a convex bow to its contour, so it can fit the concavity of the upper lingual surfaces. If the S sound is made at the edge-to-edge position, the lower incisal plane is more apt to be flatter." The final incisal edge position must be determined intraorally and verified via phonetics.1
To determine the ideal form for teeth Nos. 6 through 11, a diagnostic wax-up would be made in which anterior guidance would be re-established.2 Specifically, the lingual contours of the maxillary anterior teeth from centric relation out to the incisal edges in all excursions would be determined. However, this cannot be accurately determined until the incisal edges have been located.
Anterior guidance must be in harmony with the envelope of function, or the resulting occlusion will lack stability.3 If the contour of the upper lingual is too bulky, the tongue may interfere with it when making T and D sounds. The F or V sounds are used to determine the upper incisal edge position. The relationship of the upper incisal edges to the vermilion border of the lower lip when pronouncing the F or V sounds is one of the most dependable guidelines. This is important for control of air escaping between the upper incisal edges and the lower lip. This is necessary for proper phonetics and must be verified intraorally with provisional restorations.
Ultimately, buildups and ceramometal crowns (IPS InLine, Ivoclar Vivadent) were planned for teeth Nos. 6 through 11.
Once the diagnostic work had been completed, ceramometal crowns and build-ups would be planned for teeth Nos. 22 and 27 with attachments. Ceramometal crowns were chosen due to the limited lingual clearance. Specifically, the planned attachments were VKS-SG/SV 1.7 mm (XPdent Bredent USA), which would be small enough so that vertical room would not be compromised and very little torque would be placed on teeth.
Taller attachments are top-heavy and transfer more force to the teeth. On the other hand, the males have very little extension off the crowns, which places very little stress on the teeth. The females are fabricated from high-tech duroplast that can last up to 4 years on crown and bridge cases. The housing for the females is created as part of the partial framework. These metal housings allow easy replacement of females and extend their longevity. In this author's opinion, the SG attachment is a very versatile and cost-effective option. For this patient, attachments were selected in response to the patient's dislike of the existing "silver hooks" on her teeth.
The lower missing dentition would be replaced with a cast partial denture (Vitalium, Austenal) and double cross-linked, aesthetic denture teeth (BlueLine Esthetic Denture Teeth, Ivoclar Vivadent). The Vitalium cast partial denture was selected based on its long-standing performance as a removable partial denture. The Blue-Line Esthetic Denture Teeth, specifically the Postaris DCL, were selected based on their wear properties, function, and aesthetics.
For teeth Nos. 23 to 26, pressed ceramic veneers (IPS Empress, Ivoclar Vivadent) were planned. This material was selected based on its aesthetics and ability to match the ceramometal crowns planned for teeth Nos. 22 and 27.
Clinical Sequence and Protocol—Phase I
Prior to initiating restorative treatment, tooth No. 28 was extracted by the oral surgeon, and Puros bone grafting material was placed. The patient required 4 months for proper healing.
|Figure 3. To establish the lower incisal edge position, a putty matrix and 4 Seasons direct composite were used to create a prototype.||Figure 4. The lingual surfaces of the maxillary anterior teeth were adjusted due to their overcontoured form.|
To begin the restorative phase, the shades of the proposed restorations were determined with patient input and based upon the Vita shade guide. The final shade selection was Vita A2. Then, using a putty matrix made from the diagnostic wax-up (Virtual VPS fast-set), the lower incisal edge position was established by placing a direct composite (4 Seasons) intraorally to create the prototype (Figure 3). As described previously, the correct position was verified via phonetics. As a result, the lingual surfaces of the upper anterior teeth were adjusted due to their overcontoured form (Figure 4). This was accomplished based on phonetics.
|Figure 5. Centric relation and vertical dimension of occlusion were recorded using a bite rim and bite registration material.|
To establish centric relation and obtain a record of the vertical dimension of occlusion, a bite rim (Triad, DENTSPLY) and bite registration material (Futar D Occlusion, Kettenbach Dental) were used (Figure 5). This step was important, since the exact vertical dimension of occlusion and centric relation would be lost once the lower anterior teeth have been prepared. This record would be used to verify the proper position of the mandible and provide a posterior centric relation stop for verification of adequate tooth reduction. This record was, therefore, critical to the final outcome of the case and could not be overlooked.
Teeth Nos. 22 and 27 were prepared for ceramometal restorations, while teeth Nos. 23 to 26 were prepared for veneers. Diamond burs (Premier Two Striper Diamonds) were used for all preparations. For incisal reductions a DC1.5C diamond was selected, and a 780.9C was used for chamfer crown preparations. Veneer preparations were completed using the 770.10C, while the 285.5C was used for lingual reduction of teeth Nos. 22 and 27. Following preparation, the stump shade was determined to be ST8.
To retract the tissue prior to final impression taking, electrosurgery was performed (Macan MC-6 with a E2B tip). A nonimpregnated knitted displacement cord, size 0 (Ultradent Ultrapak), was placed with a Fisher Slide Packer (Ultradent). Stasis hemostyptic 21% ferric sulfate solution (Gingi-pak) was placed in an Ultradent 1.2-cc plastic syringe with a metal dentoinfusor tip and used for hemostasis prior to packing the retraction cord.
Final impressions were taken using an impression tray (Originate Impression Tray, Axis Dental), 3M Pentamix 2 and 3M ESPE Permadyne Penta L with impression syringe for the preparations, and Permadyne Penta H for the tray material. The bite rim and centric relation record were seated in the mouth prior to completion of the final impression. By pulling the bite rim/centric relation record in the final impression, the laboratory could mount the lower working model to the proper centric relation and vertical dimension of occlusion.
Provisional crown restorations were created for teeth Nos. 22 and 27 using a self-cure resin material (Snap, Parkell Bio-Materials Divi-sion) and cemented with Tempbond NE (Kerr). Provisional restorations for teeth Nos. 23 through 26 were fabricated directly (RSVP composite, Cosmedent).
A new face-bow transfer was not indicated at this time because the maxillary diagnostic model had been mounted previously. The final impression, face-bow mounted maxillary model, diagnostic photographs burned to a CD, and detailed laboratory prescription were sent to the laboratory (New Creation Dental Studio) for fabrication of the final restorations.
Five weeks later, the final acidetched all-ceramic veneer restorations (IPS Empress) for teeth Nos. 23 through 26 were inserted according to adhesive protocol (Variolink and Excite, Ivoclar Vivadent). The lingual contours of teeth Nos. 6 through 11 were adjusted to ideal contour and proper anterior guidance according to Dr. Dawson's concepts. The ceramometal restorations with Bredent attachments for teeth Nos. 22 and 27 were tried in, and marginal integrity was verified via explorer and radiographs.
At this time a transfer impression was taken of teeth Nos. 22 and 27, which were pulled in the impression. The Originate impression tray with Take 1 impression material (Kerr) was used. The provisional crowns were then recemented with Tempbond NE (Kerr). The transfer impression was sent to Omega Dental Laboratory for fabrication of the lower cast Vitalium partial denture framework.
Upon completion of the removable partial denture (RPD) framework, the ceramometal crowns for teeth Nos. 22 and 27 and the framework were tried in. An altered cast impression (Omni-flex) and bite registration (Futar) were taken. These were boxed, poured, and sent to the laboratory for setup of the Postaris DCL teeth for tryin. The wax setup of the RPD was tried in, and occlusion and centric relation were verified. All excursions were checked to ensure the absence of posterior interferences. The wax setup was returned to the laboratory for final processing in Lucitone 199 acrylic.
Clinical Sequence and Protocol—Phase II
|Figure 6. The definitive crowns for teeth Nos. 22 and 27 were seated.|
The ceramometal crowns for teeth Nos. 22 and 27 were cemented into place (Panavia F, Kuraray) according to the manufacturer's protocol (Figure 6). The BlueLine/Vitalium RPD was inserted using Pressure Indicator Paste (Mizzy) to relieve potential tissue impingement. Anterior guidance was harmonized to the functional border movements first when veneer Nos. 23 through 26 were inserted. Any posterior interferences to all excursions were eliminated via occlusal adjustment.
|Figure 7. Teeth Nos. 6 through 11 were reprepared to a more ideal form with a diamond bur and chamfer crown preparations.||Figure 8. A silicone putty index was used to verify adequate incisal and lingual reduction.|
At this time, the restorative treatment plan for the maxillary anterior dentition could begin. The existing crowns on teeth Nos. 6 to 11 were sectioned and removed. Caries was removed and verified with Seek caries indicator solution (Ultradent). These teeth were then reprepared to a more ideal form with a Premier Two Striper diamond 780.9C for chamfer crown preparations (Figure 7). Adequate incisal and lingual reduction (Figure 8) was verified through the use of an incisal index that had been created using Sil-Tech silicone putty (Ivoclar Vivadent) from the diagnostic wax-up of teeth Nos. 6 through 11.
Prior to final impression taking, nonimpregnated knitted displacement cord, size 0 (Ultradent Ultrapak), was placed in the gingival sulcus of teeth Nos. 6 through 11 with a Fisher Slide Packer (Ultradent, Figure 7). Stasis hemostyptic 21% ferric sulfate solution (Gingi-pak) was placed in an Ultradent 1.2-cc plastic syringe with a metal dento-infusor tip for hemostasis prior to packing the retraction cord.
|Figure 9. The midline was registered using a fast-set putty material (Virtual VPS).|
Final impressions were taken using an impression tray (Originate Impression Tray, Axis Dental) that has no palatal coverage. This conserves impression material and provides a more comfortable experience for the patient. It also saves time and material for the dental laboratory, since they do not have to cut out the palatal area of the master model prior to indexing. Additionally, 3M Pentamix 2 and 3M ESPE Permadyne Penta L with impression syringe were used for the preparations, and Permadyne Penta H was used for the tray material. A centric relation bite record was obtained (Futar D Occlusion, Kettenbach Dental), and a face-bow transfer (Artex) was taken. Finally, the midline was registered with a fast-set putty material (Virtual VPS, Figure 9).
To fabricate the provisional restorations for teeth Nos. 6 through 11, a Sil-Tec silicone putty matrix was made from the diagnostic wax-up. The provisional restorations would serve as a prototype of the final restorations, with the profile of the lips providing the proper labial position and contour. It is important that the labial contour support the upper lip in a normal, unstrained position. The lip should not bulge out or sink in and should be otherwise comfortable to the patient. The incisal third of the labial surface should be contoured back to allow the lips to come together without interference from the teeth. The lower lip should slide smoothly past the labio-incisal line angle, without interference from the incisal edge. The lower lip curvature is one of the most important factors in determining the contour of the upper incisal plane—the smile line. Functionally, the incisal edges naturally follow the curve of the lower lip. The F and V sounds are formed by constricting air between the lower lip and the incisal edge of the upper teeth. If the incisal edges are not properly placed, the patient must strain the lower lip to constrict air for proper phonetics. Note in Figure 1 how the patient's lower lip is straining to smile, and the incisal edges do not follow the curve of the lower lip because the smile line is not in anatomic harmony.
|Figure 10. During fabrication of the provisional restorations, anterior guidance and the envelope of function were adjusted.|
The labial contour must be established first. Incisal edge position moves superior or inferior as the labial surface moves anterior or posterior. Anterior guidance and envelope of function were adjusted as previously discussed (Figure 10). The provisional crown restorations were created for teeth Nos. 6 through 11 using a self-cure resin material (Snap, Parkell Bio-Materials Division) and cemented with Tempbond NE.
The final impressions, diagnostic wax-up, face-bow mounted maxillary model, mid-line index, diagnostic photographs burned to a CD, and detailed laboratory prescription were sent to the laboratory (New Creation Dental Studio) for use in fabricating the final restorations.
Laboratory Fabrication of the Maxillary Ceramometal Restorations
|Figure 11. The copings were waxed and induction cast in a noble alloy according to the putty matrix.|
At the laboratory, the upper provisional and lower completed casts were mounted on a semiadjustable articulator (Artex, Jenson Industries), and a putty matrix (Sil-Tec, Ivoclar Vivadent) was fabricated to assist in designing the metal frameworks. The copings were waxed and induction cast in a noble alloy according to the putty matrix to ensure proper porcelain support (Figure 11). The design 67 alloy (Ivoclar Vivadent) was chosen based on its compatibility with the selected ceramic (IPS InLine, Ivoclar Vivadent) as well as its affordability, which helped control material costs and benefited the patient.
Based on the aesthetic requirements of this case, a new leucite-based metal-ceramic (IPS InLine) was chosen for these restorations. This optimized ceramic represents the latest technology for porcelain-fused-to-metal restorations using simple production techniques and a variety of alloys. Additionally, because it is available in 16 Vita shades and 2 bleach shades that can be accurately matched right out of the bottle, it was the ideal material to match the adjacent surrounding dentition and restorations. In terms of the material's handling, it enabled easy build-ups of the restorations. Further, minimal shrinkage ensured predictability.
|Figure 12. Dentin porcelain was applied and baked prior to enamel layering.|
The metal copings were opaqued, and aesthetic porcelain margins were applied and fired. Dentin porcelain was then applied and baked prior to enamel layering to control shrinkage and layering thickness within the confines of the putty matrix (Figure 12). For day-to-day laboratory applications where such control is not as critical, the separate firing is not necessary, and the enamel layering could proceed.
|Figure 13. The final desired labial outline and interproximal shape was visualized with graphite pencil.|
Once the final enamel layers were applied and fired, the crowns were seated on a solid cast. Contouring of the embrasures was completed using red pencil to outline the mesial and distal transitional line angles. Graphite pencil was drawn from the red line into the interproximal space to form and visualize the final desired labial outline and interproximal shape (Figure 13).
|Figure 14. Facial anatomy and texture were defined with pencil and completed with diamond burs.|
Final mesial and distal shaping to the desired texture, which is typically smooth, was achieved with the use of silicone wheels. Facial anatomy and texture were defined with pencil and completed with diamond burs (Figure 14).
The treatment plan for this case required precise occlusal rehabilitation according to the principles developed and described by Dr. Dawson. As such, the patient was restored to centric relation from the outset using accurate jaw records, diagnostic wax-ups, and provisionalization. Therefore, controlling anterior guidance in the final restorations was simplified as a result of the attention to detail the clinician provided.
|Figure 15. A mixture of high-temperature wax and lower fusing margin porcelain was applied to fill any discrepancies.||Figure 16. Firing the margins to finished form during the glaze cycle enables the delivery of restorations with perfectly aesthetic ceramic margins.|
|Figure 17. The final crown restorations were detailed and polished, making them ready for delivery and confident insertion.|
After all functional and aesthetic adjustments were completed, the crowns were returned to an anterior segmental cast and trimmed to isolate the gingival margins, and a mixture of high-temperature wax and lower fusing margin porcelain was applied to fill any discrepancies (Figure 15). The margins were then fired to finished form during the glaze cycle, a technique that enables delivery of perfect aesthetic ceramic margins (Figure 16). Detailing and polishing the definitive crowns rendered the case ready for delivery to the doctor and insertion with the knowledge that the restorative team had met all expectations (Figure 17).
|Figure 18. Postoperative retracted view of the final restorations.||Figure 19. View of the final restorations with patient in rest position.|
|Figure 20. Anterior postoperative view of the patient in natural smile.|
Five weeks later, the IPS InLine ceramometal restorations for teeth Nos. 6 through 11 (Figures 18, 19, and 20) were tried in. Radiographs were taken to verify marginal integrity, and centric relation, anterior guidance, and envelope of function were verified. Additionally, phonetics were verified. Note in Figure 19 how the incisal edges follow the lower lip line as previously discussed; the smile line is in anatomic harmony.
The shape and shade were reviewed with the patient, and the patient provided approval to proceed with cementation. The restorations were definitively placed with a glass ionomer luting cement (Fuji I, GC America).
Planning is paramount to the success of multiphase cases such as this. Often, remakes occur as a result of improper planning or sequencing. For example, in this case, had the vertical dimension of occlusion not been registered prior to preparing the mandibular teeth, the vertical would have been lost. For this reason, using a bite rim and registration material prior to preparing the dentition is very important. Further, it is then important to pick up this bite record in the final impression so that the master working model can be mounted properly.
Additionally, developing the incisal edge position of the lower anterior dentition first is critically important. As taught by Dr. Dawson, the lower anterior teeth determine the occlusal plane for the entire case, which is why their position must be determined prior to initiating work on the maxillary dentition.
Pretreatment planning is the reason this case proceeded as smoothly as it did. There were no surprises, and a working vision of the final outcome of the case (ie, diagnostic wax-up) guided decisions regarding time, materials, and costs.
1. Dawson PE. Concept of Complete Dentistry. Seminar I, notebook. 2002: II-3 to IV-4.
2. Wynne WP. Considerations for establishing and maintaining proper occlusion in the aesthetic zone. Dent Today. Apr 2004;23:112-119.
3. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. St Louis, Mo: CV Mosby Co; 1974:16.
Dr. Tucker wishes to thank his 2 staff members, Bonnie Hannold, RDA, and Debbie Smith, RDA, RDT, for their outstanding assistance with this case.
Dr. Tucker has maintained a private practice in Erie, Pa, since 1982. A graduate of the University of Pittsburgh School of Dental Medicine, he has at-tended the Boston Seminars in Implant Dentistry with Dr. Paul Schnitman and completed the University of Buffalo Esthetic Dentistry Program, all levels at the Dawson Center for Ad-vanced Dental Study, and the University of Buffalo Patient Mastery Program. Dr. Tucker is a diplomat in the American Society of Osseointegration and the International Congress of Oral Implantologists, and holds a mastership in the American Academy of Implant Prosthodontics. Dr. Tucker has lectured throughout the United States regarding dental im-plants and prosthetics and has published numerous related ar-ticles. He can be reached at (814) 836-7777 or jtucker@ tuckerdentalexcellence.com.
Disclosure: Dr. Tucker has patented a precision attachment currently being marketed by the Preat Corporation. He patented the Originate Impression Tray and has licensed it to Axis Dental for distribution. He receives financial compensation for this product.
Mr. Jones has more than 25 years of experience as a dental laboratory technician and maintains certification in crown and bridge, as well as ceramics, from the National Board of Certification. He has worked in commercial laboratory and private practice settings and as the technical support instructor for the fixed prosthodontic programs at the University of Buffalo Dental School. Mr. Jones currently owns New Creation Dental Studio in the Buffalo area, emphasizing fixed prosthodontic and cosmetic restorations. He can be reached at (716) 446-5516.
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