Compromised Implant: An Interdisciplinary Rescue Treatment

INTRODUCTION
Implant treatment for a single missing tooth in the aesthetic zone is best considered advanced treatment due to its significantly increased complexity. The “rescue” treatment of an implant involves the correction of a previous implant procedure that has resulted in a subpar outcome. In addition to the biological considerations needed for predictable osseointegration,¹ the aesthetic zone presents additional challenges of limited interproximal and inter-occlusal space, non-axial loading forces and guidance pathways, and aesthetic challenges of replicating the tooth and gingiva.² Utmost respect and consideration must be given to biologic, functional, and aesthetic factors.^3-5 Replacement of the single central incisor with an implant is among the most challenging restorative procedures and requires strong interdisciplinary teamwork from the surgeon, technician, and restorative/prosthodontic clinicians.^6,7 The ultimate result is dependent on the success of all involved.

CASE REPORT
Preoperative Case History
A 26-year-old female patient presented for consultation regarding her left central maxillary incisor (No. 9). According to the ASA (American Society of Anesthesiologists) Physical Status Classification System, she was an ASA I (a normal, healthy patient),⁸ and she had no dental concerns beyond tooth No. 9. The details of her treatment history for this tooth were incomplete. We were able to ascertain that she had a recent history of full-mouth lingual orthodontics to correct aesthetic concerns prior to her then-upcoming wedding. The surrounding dentition was unrestored. She had a high smile line and a normal gingival phenotype⁹ (Figures 1 and 2). It was not clear why tooth No. 9 was undergoing treatment initially, nor were the preoperative radiographs available.

It was evident from the photographs obtained from her previous treatment that she had tooth No. 9 extracted and an implant (NobelReplace Conical Connection, regular platform [Nobel Biocare]) immediately placed in a 2-stage protocol (submerged). At the second stage (uncovering), it appeared that a graying of the soft tissue overlying the implant area was noted (Figure 3), and a correction was requested. At that same appointment, a screw-retained provisional was fabricated and attached to the implant. A small free gingival graft (FGG) was performed in an attempt to correct the grayed soft tissue. Five interrupted chromic gut sutures were placed (Figure 4). After healing of the FGG, the patient presented to our clinic for consultation regarding the lack of soft tissue around the implant (open gingival embrasures) (Figure 5).

Figure 1. Preoperative view of the patient at full smile; the photo was from the previous treating clinician. Note the full gingival display. She would undergo treatment for tooth No. 9 with an implant by the initial provider.	Figure 2. Close-up view of the pre-op state of tooth No. 9 and the adjacent teeth. Note the normal gingival phenotype and moderate deficiency of the papilla between teeth Nos. 9 and 10.
Figure 3. Patient presentation after healing following immediate placement of an implant at the No. 9 position. Note the reasonable volume of the papilla, though blunted. Tissues appear healthy. We suspect that the patient was distressed by the discoloration of the gingiva over the facial surface of the implant site at this stage due to her high smile line and desire for “perfect” aesthetics (photo and implant placement by the initial provider).	Figure 4. Immediate postoperative view of the free gingival graft (FGG) that attempted to resolve the discolored tissue. A screw-retained provisional was also placed. Note the relatively small size of the donor graft, the extensive suturing, the blanching of the tissues, and the displacement of the mesial papilla (photo and FGG by the initial provider).
Figure 5. This is how the patient presented to our team for consultation. She had extensive recession and clefting around the graft area. This had exposed the head of the implant and created a severe aesthetic disturbance to the site. Our team was concerned with the prognosis of the implant at this stage, in addition to the obvious aesthetic challenges faced. Our rescue treatment focused on improving the prognosis for the implant and mitigating the aesthetic deficiency of the gingiva with a pink porcelain/zirconia apron on the prosthesis.	Figure 6. Pre-rescue treatment radiograph illustrating the significant bone loss at the mesial area. The lack of bony attachment to the implant post-osseointegration and the loss of attachment on the adjacent root predict very low probability for surgical resolution of the defect.
Figure 7. We fabricated a new screw-retained composite/titanium provisional restoration prior to the surgery. A composite shell was fabricated by the technician and picked up intraorally on the titanium temporary abutment using flowable composite. It was refined and finished in the in-office laboratory.	Figure 8. The provisional was specifically designed with extensive undercontouring in the emergence and gingival embrasure areas. This was to allow room for biologic graft materials, swelling, and tissue migration to the greatest extent possible. Full resolution of the gingival defect is not anticipated.

Diagnosis
At our initial consultation with the patient, we noted approximately 5.0 mm of loss at the mesial papilla, 3.0 mm of loss at the distal papilla, and 2.0 mm of loss at the gingival zenith.^10,11 The tissues were in good health. Implant stability, osseointegration, and bone levels were measured with Implant Stability Quotient (ISQ) (using the Osstell device)¹² and radiographs. The radiographic bone level at the distal was within normal limits, and approximately 4.0 mm of bone loss was noted between the central incisors (Figure 6). Fenestration of the implant through the facial bone plate was suspected due to implant position and tissue grayness.¹³

Treatment Protocol
At the time of our consultation, the patient stressed the importance of her upcoming wedding, then about 8 months away. Our team decided to attempt to save her No. 9 implant and improve its long-term prognosis with one corrective surgery and reconstruction of the missing soft tissues prosthetically. The patient was briefed on the near impossibility of fully regaining the missing gingiva and the need for pink porcelain to correct the defect.

In preparation for her surgery, a new screw-retained provisional¹⁴ (Figure 7) was fabricated with an undercontoured emergence profile¹⁵ to allow room for graft materials, postoperative swelling, and tissue migration (Figure 8). The dental technician fabricated a composite shell from digital models (TRIOS Scanner [3Shape]). An engaging titanium temporary abutment (Temporary Abutment, engaging CCRP [Nobel Biocare]) was coated with an A1 opaque composite resin (Kolor Plus+ A1 [Kerr]) and secured directly onto the implant. The composite shell was modified by cutting away the palatal portion and test-fitted over the abutment. The shell was connected intraorally to the abutment using a flowable composite (Filtek Supreme Ultra [3M]). The combined shell and abutment were removed from the mouth. The emergence area and gaps were filled with flowable composite and then fully light cured. The titanium abutment was cut flush with the palatal contours of the shell. After contouring and polishing, the new provisional was attached to the implant, and undercontoured emergence was confirmed.

Under local anesthesia, the surgical access was created at the depth of the vestibule apical to the implant. This approach minimized the disruption of blood supply and the risk of scarring to the critical soft-tissue areas. Fenestration of the implant through the facial bone plate was confirmed tactilely. Degranulation of the implant was performed with hand instruments, and an “envelope” pouch was created to receive the graft materials. A “sticky bone” graft was created with medium-sized, particulate xenograft (crushed Bio-Oss large particle bone graft [Geitslich]) and platelet-poor plasma (from a blood draw, spun with an IntraSpin System [Intra-Lock]). The sticky bone graft was placed from the vestibular incision over the facial surface of the implant and the adjacent bone. A platelet-rich fibrin (PRF) membrane (PRF, blood spun in an IntraSpin System) was placed between the sticky bone and the flap in a “biologic layering” approach (Figure 9). The provisional was torqued onto the implant, and final suturing was performed.

Figure 9. The surgical approach was from the depth of the vestibule to minimize disruption of the blood supply to the affected aesthetic area. An “envelope” pouch was developed, and grafting was performed in a “biologic layering” approach using PRF and xenograft particulate.	Figure 10. Following healing and maturation of the surgical site, a definitive screw-retained, layered Zr/Ti prosthesis was fabricated and delivered. The pink porcelain apron was designed to reach a balance between reasonable aesthetics and hygienic access. In the course of rescue treatment for implants in the aesthetic zone, compromises are often to be expected.

Figure 11. The patient smiling with her new restoration. Note that smiling with the teeth apart reduces the translation of the lip, helping to camouflage the pink porcelain apron.

After 4 months of healing and maturation, the patient was seen for an evaluation. Collectively, it was determined that further surgeries were unlikely to improve the outcome and that the biologic prognosis of the site was good. As initially discussed with the patient, correction of most of the gingival defect would have to be accomplished with pink porcelain. An intraoral scan (TRIOS) was performed using a Nobel CCRP specific scan body. The patient visited the technician at the dental lab for shade selection of the teeth and soft tissues. A screw-retained zirconia restoration (Katana Zirconia [Kuraray Noritake]/Classic Creation Porcelain) on a titanium base with a gingival “apron” was fabricated. Careful attention was paid to maximizing aesthetics without compromising hygiene access. Following a few try-ins and minor revisions, the restoration was delivered, torqued to 35 Ncm, and then obturated using Teflon tape and composite resin (Figures 10 and 11). The patient was seen for follow-up appointments to remove the restoration and confirm adherence to hygiene protocols.

DISCUSSION
The rescue treatment of a compromised implant in the aesthetic zone is extremely challenging and will often result in compromises in the end result. It is imperative to fully debrief the patient on what is possible and likely. Interdisciplinary teamwork is essential to ensuring the best possible outcome.

In this particular case, it is likely that the patient’s desire for correction of the grayed peri-implant gingiva pushed the previous clinician to perform the FGG. In hindsight, we noted from the photographs that this is the point at which the treatment took a turn for the worse. It appears that the FGG donor tissue was too small and too tightly sutured to the recipient site to survive. Blanching of the donor tissue was evident. It was also clear that the sutures pulled the mesial papilla off the root surface of tooth No. 8, further compromising blood supply and graft survival. While we must avoid too harsh a judgment in retrospect, perhaps the graying of the tissue could have been corrected without complication using the vestibular surgical approach to augment the overlying bone and soft tissue. This appears to be a case where attempts at reaching “perfection” resulted in a drastically compromised result.

Our attempt at correcting the compromised site was limited from the start in achieving significant improvement given the state of the soft tissue after multiple surgical interventions that resulted in scarring and reduced vascularity. It is always easier to avoid complications than it is to correct them. In this case, we intended to maximize the prognosis for the implant and produce a reasonably aesthetic outcome.

The use of pink porcelain for replacing missing soft tissues for a single implant site must reach a balance between aesthetics and hygiene. Focusing too much on aesthetics for pink porcelain on a single implant will result in a non-hygienic prosthesis and compromise the implant and the adjacent teeth over the long term. A balance must be struck between hygiene accessibility and aesthetics. In general, pink porcelain is most aesthetic for larger restorations.

CLOSING COMMENTS
This treatment was originally started prior to a major life event (a wedding day) to correct what is arguably a minor problem. Looking back at the original pre-treatment photos, it would have been advisable to postpone the surgical treatment for tooth No. 9 until after the wedding. The timing constraint also placed pressure on the clinical team to perform and complete treatment in a timeframe for which biology had no concern. Prior to initiating any significant treatment, it is wise to find out if there is some upcoming event for which the patient is hoping to have dental treatment completed by. In our experience, it is not uncommon to have patients seek treatment that cannot be completed in time for their important upcoming event.

During the course of our rescue treatment with the patient, something less technical was also occurring. The patient was coming to terms with the reality that where she would ultimately end up was not where she had originally planned. Perhaps, too, she was supported by friends and family who reassured her that the outcome was satisfactory when not holding a magnifying mirror inches from her face.

Acknowledgment:
The authors would like to thank Beverly Hills Dental Lab for work done in this case.

References

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2. Schoenbaum TR, ed. Implants in the Aesthetic Zone: A Guide for Treatment of the Partially Edentulous Patient. Springer; 2019.
3. den Hartog L, Huddleston Slater JJ, Vissink A, et al. Treatment outcome of immediate, early and conventional single-tooth implants in the aesthetic zone: a systematic review to survival, bone level, soft-tissue, aesthetics and patient satisfaction. J Clin Periodontol. 2008;35:1073-1086.
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7. Mangano FG, Mastrangelo P, Luongo F, et al. Aesthetic outcome of immediately restored single implants placed in extraction sockets and healed sites of the anterior maxilla: a retrospective study on 103 patients with 3 years of follow-up. Clin Oral Implants Res. 2017;28:272-282.
8. Wolters U, Wolf T, Stützer H, et al. ASA classification and perioperative variables as predictors of postoperative outcome. Br J Anaesth. 1996;77:217-222.
9. Kan JY, Morimoto T, Rungcharassaeng K, et al. Gingival biotype assessment in the esthetic zone: visual versus direct measurement. Int J Periodontics Restorative Dent. 2010;30:237-243.
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Dr. Schoenbaum is a full clinical professor at the University of California, Los Angeles (UCLA), and director of UCLA Continuing Education. He trains residents and students at UCLA in implant restorations and biostatistics. He has published more than 50 papers, 8 textbook chapters, and one textbook. He is the recipient of the Judson C. Hickey Scientific Writing Award from the Journal of Prosthetic Dentistry. He has a master’s in clinical research from UCLA and has been invited to present his clinical and scientific work at conferences worldwide. He maintains a private practice limited to implant treatment with Dr. Peter Moy. He can be reached at tschoenb@g.ucla.edu.

Dr. Moy received his dental degree from the University of Pittsburgh, a certificate in General Practice Residency from Queen’s Medical Center in Honolulu, Hawaii, and a certificate in Oral and Maxillofacial Surgery from UCLA Hospital. He limits his practice to oral and maxillofacial surgery, focusing on surgical aspects of implant dentistry and reconstruction of the severely atrophic alveolar ridge. A clinical professor in the Department of Oral & Maxillofacial Surgery at UCLA, he is also director of Surgical Implant Dentistry and the first recipient of the Nobel Biocare Endowed Chair in Surgical Implant Dentistry. He is an associate editor for the Journal of Oral & Maxillofacial Surgery and reviewing editor for Clinical Implant Dentistry and Related Research. He has written numerous articles and book chapters and published several textbooks. He has lectured extensively nationally and internationally while maintaining a private practice in Los Angeles. He can be reached at pkmoy@ucla.edu.

Mr. Alawie is president of Beverly Hills Dental Lab. He completed his master dental technician degree in Brussels, Belgium, in 1994. He migrated to the United States in 2003 and opened his own full-service dental laboratory in Beverly Hills, Calif. Mr. Alawie is well versed on the importance of technical clinical communications and their implementations for successful case planning and patient satisfaction. He is a keen and avid supporter and member of many study groups. He instructed various hands-on crown and bridge courses and hosted presentations throughout Europe and the United States. In 2012, Mr. Alawie opened a teaching facility, Oral Design Los Angeles, with Michel Magne, which offers a spacious new venue for laboratory technicians, clinicians, and students to connect and exchange aesthetic knowledge and ideas. He can be reached at info@beverlyhillsdentallab.com.

Disclosure: The authors report no disclosures.

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