FIGURE 1 – Before view showing the asymmetric tissue contours, deficient edentulous ridge with #10 and the missing tooth #4.
FIGURE 2 – After view showing the final restoration for teeth ## 4 – 12; we have achieved achieving a natural result for the patient.
The replacement of missing teeth in the maxillary anterior region remains an esthetic challenge for dentists. One has to address the multiple difficulties in managing the tissue and prosthetics. In most situations, the bone and tissue in the extraction site have receded and collapsed which creates unnatural contours for a natural appearance to the pontic or implant. Ridge augmentation is typically required to return the pontic and implant area to the correct height and width. The implant and pontic need to be designed correctly to support the soft tissue properly resulting in natural cosmetic dental papilla and facial gingival tissue.
The materials available to dentists have been one of the biggest limitations to achieving a natural result when mixing veneers, bridges and or implants. This often requires multiple substructure materials and multiple systems. As a result, it is difficult to fabricate matching lifelike restorations due to inconsistencies to value, chroma and hue. The design and materials must also allow for normal connector widths, which have been a problem with some of the all-porcelain or fiber-reinforced composite resin systems1. Now with the ability to combine zirconium substructures and IPS e.max ZirPress the dentist and dental technician can work in partnership to restore even the most challenging cases using one high strength all-ceramic system. This includes anterior single tooth implants.
The following case will show the use of zirconium frames and copings that are designed in such a way that once they are pressed with the same ceramic material as the veneers it will be difficult to distinguish between the veneers bridge and implant (Figs. 1 & 2).
This 28-year-old patient presented with an unnatural looking porcelain fused to metal bridge on teeth## 9-11. The tissue apical to the pontic #10 was collapsed buccally lingually. Tooth #4 was lost due to a fractured root (Fig. 3) Her tissue heights had asymmetric contours (Fig. 1). Her lower anterior teeth were slightly rotated. Her posterior restorations were all in good repair. She felt she clenched or ground her teeth at night and the wear facets discovered supported her observations. The patient demonstrated excellent oral hygiene with no periodontal pockets. Radiographs revealed good bone support and no tooth decay. There were no TMJ signs or symptoms2.
A full mouth series, AACD slide series, digital photo series, models mounted with a KAVO facebow transfer, centric relation bite registration (mounted on a KAVO Protar articulator), a horizontal bite stick, intraoral exam and a full mouth pocket charting.
The dentist and ceramist carefully studied the patient’s records and developed a smile design that would be reproduced in a diagnostic wax-up. This was used as the template to guide the surgeon, ceramist and dentist throughout the restorative dental treatment.
To achieve the desired result the treatment plan consisted first the straightening of her lower teeth then removing her porcelain fused to metal bridge and fabricating an acrylic provisional so the oral surgeon could have access to the pontic site. She would be referred to the surgeon to augment the ridge at the #4 and #10 site creating a normal buccal-lin-gual width. Two months later an implant would be placed at the #4 site and the tissue would be repositioned with teeth ##7 and 9. The provisional would be adjusted periodically to create an ideal ovate pontic site. Approximately six months after the implant placement, Brite Smile Whitening would be done and then the final restorative phase could begin. The following restorations were treatment planned as follows: Tooth #4: Custom milled metal/ zirconium abutment with an IPS e.max ZirPress ceramic implant crown. Tooth #5: IPS e.max ZirPress ceramic veneer. Tooth #6: IPS e.max ZirPress ceramic veneer. Tooth #7: IPS e.max ZirPress ceramic veneer. Tooth #8: IPS e.max ZirPress ceramic veneer. Teeth ##9, 10 and 11: Milled zirconium frame designed to fit on the lingual of teeth ##9 and 11. Leaving the facial of the preps in natural dentin (fig. 4)IPS e.max ZirPress is pressed over the zirconium frame. Tooth #12: IPS e.max ZirPress ceramic veneer.
The use of zirconium allows for the development of ideal connector sizes without compromising strength. The new system by Ivoclar allows the ability to press ceramic to a zirconium core. This system was preferred to the Authentic system which requires a similarly designed substructure (but in metal) and this can result in metal shine through. Zirconium also works well for custom milled abutments since it has adequate strength and creates a natural dentin color for the over lying ZirPress crown and gingival tissue (Fig. 5).
The oral surgeon elected to do a subepithelial connective tissue graft at the #10 site and leave the #4 site alone. The graft was placed under a partial thickness flap that was elevated over the ridge deformity. The connective tissue graft was taken from the hard palate adjacent to the premolars. He also positioned the distal gingival tissue with #9 more apical to place the gingival zenith just distal to the central axis of the tooth (Figs. 6 & 7).1 The pontic of the provisional bridge was recontoured to help develop the ovate pontic site. One month later the pontic was modified again to help create ideal papillae and facial gingival contour. The following month the patient returned to the oral surgeon to have a 4 mm x 13mm 3-I Certain implant placed in the #4 site with a 6mm profile healing abutment. During the six month healing phase tooth #9 needed RCT and that was performed by an endodontist.
Six months after the implant placement she was released by the oral surgeon to begin the restorative phase of her treatment. Since the patient wanted whiter teeth she had a Brite Smile Whitening visit. Two weeks later I reviewed the treatment goals once again with the patient verifying shade, degree of translucency, facial anatomy and incisal characteristics. At this point we could begin the restorative phase of her treatment.
The treatment sequence involved the following appointments:
At the first appointment she was anesthetized using Citanest 4% Plain and then following up with Articaine HCL 4% with epi. Once profound anesthesia was confirmed teeth ##9 and 11 were prepared for ceramic crowns. Then, teeth ##5,6,7,8 and 12 were prepared for ceramic veneers. The Newport Coast Oral Facial Institute Esthetic preparation kit from Brassler was used to perform the incisal, occlusal, facial, lingual and interproximal reductions. The clearance was guided by using the clear matrix and a putty matrix (from the diagnostic wax-up) as reduction guides. I designed the preparations using the following protocol: teeth ## 9 and 11 had clearance at the incisal by 1mm, the lingual by 1.5mm, facial and interproximal by 1mm.
The remaining veneer preparations with teeth ##5,6,7,8,9 and 12 had clearances of .6mm on the facial, 1mm on the incisal. The lingual margins were wrapped around the incisal onto the lingual above the centric stops. The interproximal was elbowed into the lingual to hide the interproximal margins without completely breaking the contact.3,4
I lowered and smoothed the .6mm butt shoulder on all the preparations with a large TGE 1.6 f end cutting bur to just below the gingival crest.4 The laboratory fabricated a clear stint which was used to check for adequate reduction. Holes were placed in the facial and lingual aspects of the stint and a periodontal probe was used to measure the amount of reduction. A laboratory made putty matrix was also used to evaluate for adequate reduction. At this time I determined the prep shades to be st 9, and digital photos were taken to aide the ceramist when he was selecting his ingots and evaluating the final shade and color on the appropriately shaded dies. The gingival zeniths were slightly adjusted with an electrosurge and the margins were adjusted just below the gingival crest.
The healing abutment was removed and a 3-I closed tray impression coping was placed. Ultradent size 0 retraction cord was carefully placed in the gingival sulcus of teeth ##5-12 and let sit for 3 minutes. Then two full arch impressions were taken with 3-M/ESPE vinylpolysiloxane. The opposing was taken with alginate and hydrocolloid and poured in Denstone for a hard accurate opposing model. A new face bow was taken along with a bite stick recording. An acrylic bite registration was taken in centric relation using the equilibrated unprepared posterior teeth for centric stops.
The provisional restorations were fabricated using a vinylpolysiloxane matrix made from the duplicated diagnostic wax-up. Shade A1 Protemp 3 Garant was placed inside the matrix and then the matrix was placed over the teeth. Well detailed provisionals were formed with this technique. Final attention was made to contour the gingival margins in order to properly position the gingival tissue heights, zenith positions and the papilla for the ovate pontic site #10. The provisionals for ##5-12 were cemented with Tempocem NE. The healing abutment for #5 was placed since this maintained the proper gingival contours.
I followed up with the patient at 3 days, 7 days and 14 days. At these appointments incisal edge contours were modified to create the best function and form.5 Special attention was paid to the anterior guidance and smooth transition to the cross over posi-tion.6 The width to length ratio of the central incisors were 76% and the embrasures and facial contours fit well with the shape of the patients face.1 She was very pleased with the look of her provisionals. The patient was comfortable with her TMJ and muscles and by the third appointment I felt comfortable to begin fabricating her restorations. A model of the upper arch was taken (to show contours of the provisionals) and sent to the laboratory with the face bow mounted working models and final prescription and photos.7,8
Once the model work was completed, fabricating a custom milled abutment for tooth #4 was the first step. A 3-I Certain UCLA gold abutment was waxed for proper emergence, casted and finished. This was front-end designed for a custom abutment to be fabricated using Wieland ZenoTec milling technology. Along with the abutment the frame work was designed for teeth ## 9, 10 and 11. Adapting a press-to-metal procedure to zirconium, the facial surface of the framework was eliminated with the zirconium substructure resting solely on the lingual of teeth ## 9 and 11 (Fig. 4). This substructure design was waxed, scanned and milled by Wieland ZenoTec. The zirconium abutment for tooth #4 was composite bonded to the cast metal substructure then scanned for the fabrication of the zirconium coping (Fig. 5).
After receiving the zirconium components from the milling center, the entire case was waxed to full contour. Teeth ## 5,6,7,8 and 12 were waxed and prepared as traditional ceramic veneers. Teeth ## 4,9,10 and 11 were high fired with IPS ZirLiner to act a bond between the pressed glass and zirconium framework and also gave fluorescence to the zirconium substructure. Teeth ## 4,9,10 and 11 were waxed to full contour. All restorations were pressed, cut back, porcelain layered back into the incisal 2/3’s then contoured and finished. Before delivering the final restorations to the restorative dentist the entire internal portion of the ceramic restorations were etched with ceramic etching gel.9
At this next appointment she was anesthetized as previously done. Before the ovate bridge could be tried in, the edentulous ridge had to be slightly modified to create the most natural appearance to the pontic. Ink from a color transfer applicator (Great Plains Dental Products) was used to mark the tissue side of the pontic and the bridge was seated as far as the soft tissue ridge would allow. This would mark the tissue where the pontic made contact. An electrosurgical loop was then used to remove tissue. This was done incrementally, until the proper amount of tissue was removed. The tissue continued to blanch for a minute or two after the ridge was socketed. This ensured lateral pressure by the pontic to push the adjacent papilla incisally. Then various try-in gels were used. 3-M translucent light cured resin cement was selected. Since the dentin color was light (st9) and equal in color with all the teeth, the same resin could be used for teeth ##5-12.10
Finally, Ivoclar Translucent Multilink was selected for tooth #4. The porcelain seemed too thick for light transmission so a dual cure was the favorable choice. The restorations were then bonded in place using the tack and wave technique, finished and polished.
At the follow-up appointment, final esthetics, phonetics, guidance and occlusion were evaluated and came out very close to what we achieved in the provi-sionals.6 This was all fine tuned and polished. A new mandibular CR splint was fabricated to protect her new restorations. She was instructed to wear this when she slept.11 Two weeks later final slides were taken.
In this era of modern restorative dentistry, there are many materials and techniques for replacing missing teeth. Using IPS e.max ZirPress pressed to zirconium, allows the restorative dentist to use the same porcelain for veneers, bridges and implants. This opens the door to achieving beautiful consistent results in these more complex esthetic cases (Figs. 3, & 8-10).
Dr. Marc Montgomery received his DDS from the University Of Minnesota School Of Dentistry in 1986. For the last 20 years he has focused on high-quality, cosmetic-oriented family dental care in Woodbury, MN. He has been named Minneapolis St. Paul Magazine’s Top Dentist three times (2000, 2002 and 2005). He is an AACD fellow, an accredited member of the American Academy of Cosmetic Dentistry, participant and member of the L.D. Pankey Alumni Association, vice-pres-ident of the Minnesota Academy of Cosmetic Dentistry.
Oral Health welcomes this original article.
The author would like to thank Dr. Steve Rodenburg for his exceptional surgical treatment in this case. The author would also like to thank Ron Stevens and Pheng Lor owners of Reflection of Light dental laboratory for their contribution to the beautiful lab work that made this case so successful.
This article, A New Technique in Achieving Ideal Esthetics in Mixing Veneers, Bridges and Implants in the Smile Zone, may also be found on the Oral Health Group site, where it was published on April 1, 2007. Optimized by Hill Web Marketing.
Thank you Dr. Montgomery and the whole team for great care, easy to bear, for a friendly atmosphere and a result out of this stratosphere!