Single Tooth Replacement: The Ultimate Aesthetic Challenge (April 01, 2009)

by Bruce Kleeberger, DDS

Patient J. R., aged 19 years, attended the dental office with a chief complaint of a failing upper right central incisor. He was seeking a second opinion regarding his options for replacing the tooth. He was excited by the option of immediate implant placement and provisionalization because his appearance during the healing interval was a great concern. He felt, if his situation would permit it, the transition from failed restoration and root to the definitive restoration without at any time needed to manage a removable prosthesis was a huge benefit.

With careful case selection, providing a restoration immediately following the loss of a tooth offers to the patient the benefit of minimal inconvenience. A thorough review of literature1,2 reveals good success reported with this procedure when assessing the implant integration. However, the additional benefit of carefully planned soft tissue management cannot be overestimated. In the aesthetic zone, the support of soft tissue and creation of an undetectable restoration, is very much enhanced when it can be managed beginning at the time of tooth loss. Any pre-surgical preparation necessary including periodontal and orthodontic procedures that create an improvement in the environment before tooth removal should be considered. 3

In the case of the single missing anterior tooth, preparation of an ideal soft and hard tissue environment is technically difficult. In addition to soft tissue management, in order to create an undetectable restoration in the aesthetic zone, all of the components of shade (value, chroma and hue), translucency, contour, anatomy, texture and polish must be considered.

CASE REPORT

The patient attended the dental office for initial consultation. His upper right central crown was placed several years previously but had been dislodged and re-cemented on a temporary basis. The tooth had been restored with the full coverage porcelain fused to metal crown and cast post. The initial injury occurred when he was seven years old during an extreme-sports incident. The right central incisor demonstrated class 1 mobility and 3mm probing depths except for a narrow defect of 7mm on the disto-lingual line angle. A root fracture was diagnosed radiographically and with clinical examination. The intact buccal plate was considered thin and at risk for rapid resorption following tooth loss. The maintenance of the buccal plate of bone is important to support the soft tissue and any graft material used at the time of tooth extraction and implant placement.

There were no medical contraindications to treatment. The dental examination revealed no significant findings of restorative or periodontal issues. An examination of the muscles of mastication and temporomandibular joints revealed they were healthy. Occlusally there was significant, and more than age appropriate, wear of the cuspids and first bicuspids but that the patient had protective anterior guidance. 3 Thorough records including necessary radiographs, photographs (Figs. 1-6) mounted models, and occlusal analysis were prepared.

TREATMENT PLAN

The restorative options included: a removable or fixed prosthesis (with either full coverage crowns or bonded external wings as retainers) and an implant supported restoration. After consultation with Dr. Jennifer Cote, DDS, DIP PERIO, MRCD(C), the treatment plan was finalized. It was decided that in order to preserve the soft and bony periodontal tissue; an implant placed at the time of atraumatic surgery was an optimal treatment option.

In order to control tissue contours, it was necessary to co-ordinate the restoration of the soft tissue support with a customized provisional on the same day as the placement of the immediate implant. The AstraTech (AstraZeneca Group) implant was chosen for the case because of its innovative soft tissue management system (BioMangement Complex™).

The tooth was extracted atraumatically and the implant placed at the same appointment. The patient travelled immediately to the restoring dentist’s office for provisionalization. The implant location was planned to allow for screw hole access through the lingual of the final restoration.

In the restoring dentists’ office, the healing abutment was removed and the location of the implant confirmed. The screw access was lingual of the incisal edge which was acceptable for retrievability of the provisional. An AstraTech temporary abutment was selected and opaque BisGMA resin applied to block out the metal. An omnivac matrix had been formed from the pre-treatment model and was used to form the incisal half of the provisional restoration according to the layering technique described by the author3 by packing composite (Esthet-X, Dentsply) into the matrix, seating it over the temporary abutment in the mouth, and light curing. The waxing screw was removed and the matrix removed with the provisional still inside. The remainder of the provisional was hand sculpted to create natural contours in three dimensions, shades in layers, and emergence profile from the shoulder of the temporary abutment through the soft tissue and emerging from the sulcus. (Figs. 7A-F). The abutment was polished to a high gloss (Enhance and PoGo cups, Dentsply). The access opening to the screw hole was filled with cotton pellet and flowable composite of a contrasting shade so that it would be easier to locate at time of removal.

During the subsequent healing period the restoration and implant were monitored on a four week recall schedule. Excessive contour of the restoration on the labial can result in apical migration of the margin. Inadequate support of the papilla can result in loss of papilla height and create “black triangles”.

Five months after implant placement and provisionalization, the soft tissue health and contour was excellent (Fig. 8) and ready for the restorative impression. An open tray technique is preferred. As the soft tissue detail must be captured precisely, flowable composite can be placed around the pick up transfer coping before the impression to prevent collapse of the unsupported soft tissue and prevent distortion during the impression procedure. Communication of shade to the laboratory was enhanced using photographs (Fig. 9).

Analysis of the mounted model with the implant analog and soft tissue revealed it would be best to use select a two piece cemented restoration2,4 with a gold coloured abutment and an all ceramic crown.

In order to provide adequate access to the margin for cement removal, the margin of the abutment was designed to be sub gingival by .75mm labially and .5mm interproximally. It was placed at the gingival margin lingually. An all ceramic crown (Cerec In-Lab) was fabricated (Figs. 10 & 11). The abutment was torqued into place (Fig. 12) according to the manufacturers’ instructions and the crown tried in for occlusion, passive fit and shade. It was cemented with Rely-X Luting Cement (3M Corporation). The occlusion was adjusted to produce shimstock clearance in light posterior contact and shared disclusion with at least one anterior tooth in protrusive excursions. 5

Follow-up four weeks after cementation revealed healthy soft tissue, acceptable occlusion and a happy patient (Figs. 13 – 18).

CONCLUSION

This case demonstrates the issues to be addressed in creating the best possible outcome in single tooth replacement in the aesthetic zone. The issues of treatment planning, provisionalization, soft tissue management and abutment selection are illustrated. As always, it is important to consult with the patient to ensure all needs and wants are met and to begin treatment with the final outcome in mind.

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Dr. Kleeberger Is A GP In Langley, BC. He is an alumnus of the Millennium Institute in Calgary and of PAC~Live programs at UOP in San Francisco. He can be reached atdrkleeberger@telus.net.
The author mentors the Fraser Valley Dental Fundamentals Study Club, which is, in part, supported by Dentsply Canada.

Oral Health welcomes this original article.

References

1. Stanford, CM, What factors must be considered in planning placement of a crown supported by a single-tooth implant? JCDA 72 (5) 2006.

2. Attard, N. J., Zarb G. A. Immediate and early implant loading protocols: A literature review of clinical studies. Journal of Prosthetic Dentistry 94:3 September, 2005.

3. Kleeberger, B. Functional Esthetic Restoration with Direct Composite Resin. JCDA 200874(4) 345-350.

3. Nixon, RL, Dentistry’s Esthetic Mt. Everest: Undetectable Restoration of a Single Discolored Maxillary Central Incisor. Oral Health April, 2003.

4. Michaelakis, K. X., Hirayama, H., Garefis, P. D. Cement-retained versus screw-retained implant restorations: a critical review. Int. J. Oral Maxillofacial Implants 2003 18:5.

5. Misch, C. E. Dental Implant Prosthetics St. Louis, MO: Mosby Esvier: 2005.

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In the case of the single missing anterior tooth, preparation of an ideal soft and hard tissue environment is technically difficult

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ABSTRACT

The aesthetic restoration or replacement of the single anterior tooth remains one of the most challenging procedures in contemporary dentistry. This is due in part to the importance of soft tissue preservation to meet the challenge of creating an undetectable restoration. This article will illustrate an instance of replacing a single maxillary incisor tooth with an implant retained restoration. This is a clinical situation in which the immediately provisionalized implant is the preferred restorative option.

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The patient travelled immediately to the restoring dentist’s office for provisionalization

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During the subsequent healing period the restoration and implant were monitored on a four week recall schedule

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