Patients often present to our dental practices with serious concerns and dental complications. Problems in the aesthetic zone can complicate our treatment options when we’re trying to provide a proper emergence profile and smile design in the front of the mouth. Patient satisfaction in regard to form and function is a challenge. But, with proper protocol and treatment planning, we can achieve a high degree of aesthetics without preparing the adjacent teeth. Conventional dental procedures such as bridges and removable appliances have served us well over the years. However, as the design and prosthetic applications of our most modern dental implants have improved, dental implants provide an outstanding alternative to conventional techniques.
Implants are, and should be, prosthetically driven. This concept means that there must be an understanding or visualization of the final product prior to any surgical intervention. In the past, this was an art that was learned through experience by the most seasoned clinicians. As technology has advanced, and CAD/CAM design has become mainstream, dentists have become proficient in providing outstanding final prosthetic outcomes.
Proper Treatment Planning and Surgical Placement
The first step in providing an acceptable functional and aesthetic result is proper planning and surgical placement of the dental implant. Certain rules must be followed to allow our laboratory technicians to properly create the final crown. Understanding the physiologic response of bone and tissue, first traumatized and then interrupted with a titanium fixture, is important.
Osseo-integration is the process whereby bone attaches to the surface of the titanium, allowing the implant to become a solid foundation for the eventual prosthesis.1 Following most extractions, bone will necessarily reorganize and shrink. In the pre-maxilla, this bone change occurs in the crestal and facial portion.2 An atraumatic extraction of the nonrestorable tooth, whereby the facial plate of bone and the interseptal bone are maintained, is a good first step in trying to achieve a result that mimics the contours of a natural and healthy tooth.
Creating tissue contours in the aesthetic zone can be a challenge, so techniques that maximize bone and tissue health are a real benefit. The shape of the final crown can be determined using custom components that are most like the shape of the natural dentition. The resulting bone morphology following tooth extraction will determine the course of action that is most appropriate.
When all 4 walls (mesial, distal, palatal, and facial) are intact, the implant can be strategically positioned on the palatal side of the socket.3 The resulting gap between the implant and facial wall can be filled in with a graft material. When this gap is greater than 2.0 mm, a membrane should be used to protect the graft material from invagination of epithelial tissue into the crestal aspect.4 If the facial wall is missing, the implant can still be immediately placed following extraction, assuming the implant is initially stable. A facial wall can be created with an allograft material as long as it is protected with a membrane from invagination of the epithelium.
In this article, we will discuss the step-by-step process of attempting to maximize a soft-tissue profile with an atraumatic extraction, simple socket preservation, and proper implant placement to allow for the prosthetic components created by the dental laboratory to meet the dentist’s and patient’s visual expectations.
Figure 1 shows a preoperative digital radiograph illustrating a fractured maxillary left central incisor. Figures 2 and 3 show the result of trauma to the maxillary central incisor. This tooth was obviously unrestorable and would require careful removal. The patient was aware that the tooth needed to be removed and exhibited a lot of emotion about losing a front tooth. Having empathy and confidence in what we know can predictably be achieved in our final case outcomes can alleviate some of our patients’ concerns.
|Figure 1. The preoperative digital radiograph showed a fractured maxillary left central incisor.|
|Figures 2 and 3. The intraoral view shows the results of the trauma to the maxillary central incisor.|
|Figure 4. CBCT analysis (PaX-i3D Green (Vatech America) demonstrated a thin facial plate of bone and impingement into the nerve canal.|
In this patient’s situation, treatment options included the removal of the nonrestorable root and preparation of the adjacent teeth and fabrication and placement of a conventional, 3-unit bridge; the fabrication of a removable appliance; or the placement of a dental implant and restoration with an all-ceramic crown. The patient elected for a single-tooth replacement using a dental implant.
A CBCT analysis (PaX-i3D Green [Vatech America]) (Figure 4) showed there was a thin facial plate of bone and impingement into the nerve canal. The tooth was extracted atraumatically with Physics Forceps (GoldenDent) to maintain the facial plate of bone (Figures 5 and 6). A postoperative radiograph (Figure 7) was taken to verify the complete removal of the root.
Figures 8 to 10 illustrate the use of osteotomy burs (provided in the Hahn Tapered Implant System [Glidewell Laboratories] and used to create the initial preparation), which were followed by widening burs that prepared the conical design. The palatal wall of the socket was engaged as the burs were positioned approximately 3.0 mm palatal to the facial aspect of the adjacent teeth. This was done to protect the facial plate of bone, to help create proper emergence profile, and to allow room for the custom abutment and crown material.
|Figures 5 and 6. To maintain the facial wall of bone, an atraumatic extraction was done.|
|Figure 7. A postoperative radiograph verified the complete removal of the root.|
|Figures 8 to 10. Osteotomy burs (provided in the Hahn Tapered Implant System [Glidewell Laboratories]) were used to create the initial preparation, followed by the use of widening burs. The palatal wall of the socket was engaged. The burs were positioned approximately 3.0 mm palatal to the facial aspect of the adjacent teeth to protect the facial plate of bone and to help create the proper emergence profile.|
The socket created was shaped similar to an egg. Since our implants were round, the gap between the facial plate of bone and the palatally positioned implant was filled in with an OsteoGen Plug (Impladent) (Figures 11 and 12).5 This material helped to prevent the palatal shrinkage of the bone during the integration process.
The Hahn Tapered Implant was then threaded into the prepared site and torqued to 40 Ncm (Figure 13). The postoperative digital radiograph (Figure 14) verified the position of the implant slightly apical to the crest, which would allow for the biological width of bone to re-establish itself. The postoperative CBCT (Figure 15) verified the position of the implant in the available bone and the positive maintenance of the facial plate of bone.
To expedite the aesthetic process, a conventional polyvinylsiloxane impression was immediately taken of the surgically placed implant. It was sent to the dental laboratory team (Glidewell Laboratories, Newport Beach, Calif) for the fabrication of transitional components. Once received at the laboratory, an analog was attached to the impression coping, and a soft-tissue model was poured. Next, a scan body was screwed into the analog of the model and scanned (TRIOS [3Shape]). Once the model was scanned into the software (3Shape), a variety of custom abutments could be chosen and created, such as healing abutments, temporary abutments, and final abutments.
|Figures 11 and 12. An OsteoGen plug (Impladent) was used to graft the socket following implant osteotomy preparation.|
|Figure 13. A Hahn Tapered Implant was threaded into the prepared site and torqued to 40 Ncm.|
|Figure 14. A postoperative radiograph verified the final position of the implant, slightly apical to the crest.||Figure 15. A postoperative CBCT illustrated the position of the implant in the available bone and positive maintenance of the facial plate of bone.|
|Figures 16 and 17. CAD/CAM design of the custom abutment and implant-retained crown was completed by the dental laboratory team and evaluated for proper contours.|
Figures 16 and 17 illustrate the CAD/CAM design of the custom abutment and implant crown. This design was sent to me for evaluation and final approval. The dental technician can mirror image the contra-lateral tooth within this system to allow for symmetry.
Following 4 months of integration of the maxillary anterior implant, the custom transitional abutment was seated (Figure 18). This was fabricated from an impression made at the time of surgery, so the soft-tissue contours may have changed a little in the interim. A composite transitional crown was seated. This begins the shaping process of the soft-tissue contours (Figure 19). All contours would need to be evaluated prior to fabrication of the final restoration.
Following a 3-week period, the custom-fabricated impression coping was used to precisely duplicate the tissue contours that had been created by the transitional abutment and composite crown (Figure 20). Upon removal of the transitional abutment, one can clearly see in Figure 21 how the soft-tissue contours mimicked the natural-looking contours of the transitional abutment and crown.
|Figure 18. A custom transitional abutment was fabricated to help create and maintain proper soft-tissue contours and interdental papillae.||Figure 19. A composite resin transitional crown was seated to begin shaping the tissue contours. (Note: Contours need to be evaluated prior to fabrication of the final restoration.)|
|Figure 20. Following a 3-week period, a custom impression coping was used to precisely duplicate the soft-tissue contours that had been created by the transitional abutment and crown.||Figure 21. The soft-tissue contours mimicked the natural-looking contours of the transitional abutment and crown.|
A final zirconia custom-milled abutment (BruxZir [Glidewell Laboratories]), with margins at or just slightly subgingival, was seated and torqued to 35 Ncm (Figure 22). The interdental papilla and facial soft tissue were maintained. Figures 23 and 24 show the final stained and glazed lithium disilicate crown (IPS e.max [Ivoclar Vivadent]) cemented (IMPROV cement, Salvin Dental, Charlotte, NC) into place. Note that the contours resembled the natural dentition. Final cement removal was simple and complete because the margins were easily visualized. Figure 25 illustrates the final smile design that was aesthetically and functionally acceptable, as well as pleasing to our patient.
|Figure 22. A final zirconia custom-milled abutment (BruxZir [Glidewell Laboratories]) with margins at or just slightly subgingival is torqued to 35 Ncm. The interdental papilla and facial soft tissue were maintained.|
|Figures 23 and 24. The final lithium disilicate (IPS e.max [Ivoclar Vivadent]) crown was cemented (IMPROV cement, Salvin Dental, Charlotte, NC) into place. (Note that the contours were similar to the natural dentition.)|
|Figure 25. The final smile design was aesthetically and functionally acceptable and the patient was happy with the outcome.|
The clinical protocol shared demonstrates how to predictably achieve a functional and aesthetic final implant-retained crown. In summary, for the case presented herein, this was accomplished though proper surgical positioning and control of the interseptal bone and interdental papillae using custom transitional abutments. The tissue was allowed to heal around the root-shaped abutments during the implant’s integration time. The final impression was made with a similarly shaped impression coping, enabling our lab team to visualize what was present intraorally. CAD/CAM-designed abutments, transitional appliances, and final prostheses were visualized by the dental technician and the dentist, then duplicated during the milling process.
Dental implant replacement has become a popular and predictable method of successfully restoring form and function, even in the challenging aesthetic anterior maxillary smile zone. Becoming aware of the surgical and prosthetic challenges involved in this area of the mouth is important to achieving predictable success. Success, in these cases, refers to the integration of the implant, functionality of the final crown, and patient acceptance of the outcome.
Picking the right implant for the individual circumstance will help in providing the initial stability of the implant. Having options as to the prosthetic components, including the ability to use custom-shaped abutments, will allow for an emergence profile where the implant-retained crowns appear to come right out of the tissue like a natural-looking tooth. Building the foundation for our competent dental laboratory team allows for the creation of an optimal result, even in the challenging smile zone.
The author would like to thank Glidewell Laboratories (Newport Beach, Calif) for the work performed in this case.
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Dr. Kosinski is an affiliated adjunct clinical professor at the University of Detroit Mercy School of Dentistry (Detroit Mercy Dental) and is the associate editor of the AGD journals. He is a past president of the Michigan Academy of General Dentistry. Dr. Kosinski received his DDS from Detroit Mercy Dental and his Mastership in Biochemistry from Wayne State University School of Medicine. He is a Diplomate of the American Board of Oral Implantology/Implant Dentistry, the International Congress of Oral Implantologists, and the American Society of Osseointegration. He is a Fellow of the American Academy of Implant Dentistry and received his Mastership in the AGD. He has received many honors, including Fellowships in the American and International Colleges of Dentists and the Academy of Dentistry International. He is a member of Omicron Kappa Upsilon and the Pierre Fauchard Academy. He was the Detroit Mercy Dental Alumni Association’s Alumnus of the Year, and in 2009 and 2014 he received the AGD’s Lifelong Learning and Service Recognition. He has published more than 160 articles on the surgical and prosthetic phases of implant dentistry. He can be reached at (248) 646-8651, via email at email@example.com, or via the website located at smilecreator.net.
Disclosure: Dr. Kosinski reports no disclosures.