Solving the Challenge of the Severely Compromised Implant in the Esthetic Zone: An Interdisciplinary Care Case

Implant dentistry is considered an excellent treatment option for replacing lost or missing teeth and has the ability to improve the quality of life for the recipient patient.1-5 However, although 3- to 4-year follow-up reports of implant success rates are claimed by some authorities to be close to 95% to 97%,6-9 in reality this is likely to be considerably lower in general dental practices (81.3 %).10 Such factors as patient selection, clinical skill, and maintenance all can impact outcome.

In 2009, a female patient in her early 30s presented for consultation related to a severely compromised implant in the left maxillary central incisor region, No. 9 (Figure 1 and Figure 2). The patient’s chief complaint was that her implant looked “ugly” and that she was reluctant to smile at all. She said the situation made her feel “ugly.”

A full and detailed history indicated that the patient had been having problems with her confidence and was being treated for depression by her medical doctor. She also provided a very complete and documented dental history, including copies of clinical notes along with radiographs of her previous dental treatments from before the upper left central incisor was removed and the implant placed.

The history revealed that her problems had begun with a traumatic accident at the age of 12 when she fell off her bicycle. The maxillary left central incisor was damaged and subsequently required endodontic treatment. Later retreatment included both orthodontics and retrograde root canal fillings. However, as a result of all this therapy, the tooth was structurally compromised, and in 2005, the tooth fractured horizontally below the free gingival margin, as can be seen in a radiograph taken at that time (Figure 3).

The tooth was deemed hopeless, and treatment options presented to the patient included: extraction and a bridge; an implant; or a removable denture. The treatment chosen was extraction of the tooth and implant placement. Placement was achieved using a staged approach—starting with initial extraction of the root, curettage of the site, then hard-tissue demineralized bone augmentation with soft-tissue closure.

The site was allowed to heal for 4 months before a second-stage surgery to place the implant was performed. A tissue-level implant with a platform dimension of 4.8 mm was placed and allowed to integrate, and the patient was returned to the general dentist for completion of treatment.

The initial restorative treatment plan was to allow the soft tissues to form against a provisional crown and, once they matured, a permanent restoration would be placed. However, the provisional crown—although initially screw-retained—kept fracturing. The restorative dentist was unable to control the situation and resorted to a cemented restoration, which also failed on several occasions, resulting in re-cementation procedures with more permanent adhesive luting cements. Some of the cement remained under the gingival tissues, causing inflammation within the tissues. Evidence of residual excess cement around the implant site, as well as developing bone changes, was evident on copy radiographs the patient had in her possession (Figure 4). The implant site continued to worsen, resulting in pathological bone loss, peri-implantitis.

Another result of the peri-implant disease was the loss of papilla between Nos. 9 and 10, with the implant site now esthetically compromised in a patient with a high smile. At this point, the patient was referred to a series of different periodontists, who, combined, carried out at least seven attempts at augmentation/regenerative surgery to try and rectify the situation. Ultimately, the outcome was poor. The soft tissue around the implant and the papilla adjacent to the lateral incisor receded. The temporary implant crown was removed and the patient was provided with a removable flipper-type restoration.

The flipper also presented issues for the patient, as it failed to be adequately retained during function and speech. Therefore, one of her former treating dentists opted to improve the situation by providing a guide plane on the adjacent central incisor. This reduced the mesial–distal width of the adjacent central incisor (tooth No. 8) and further compromised the situation esthetically.

It was at this point, 4 years after the original tooth extraction, that the patient self-referred to a periodontist’s (KA) office for evaluation. After listening to the patient’s complaints and receiving information on the previous therapies rendered, it became apparent to the periodontist that this was a complex case that would require an interdisciplinary specialist approach. The patient was referred to a prosthodontist (CW) and an orthodontist (JY) for further evaluation. Once examinations were completed, the three specialists conferred to identify issues and discuss possible solutions.

Consultations between the periodontist, prosthodontist, and orthodontist specialists concluded that several issues negatively contributed to the case:

Implant type—The implant was a tissue-level type, where the implant neck becomes wider than the implant body and is ultimately the restorative platform. One of the design advantages of this type of implant is that there is no abutment/implant junction at bone level.¹¹ This has been shown to reduce bone remodeling if the implant is placed appropriately.¹² The restorative options are somewhat limited in this situation, as the horizontal and vertical dimensions tend to increase, resulting in tissue encroachment, which is what occurred in this case (Figure 5). Although the implant appeared appropriately placed in all three dimensions to maximize its macro design, its apparent shallow placement depth made it more challenging to submerge the implant.

Provisional management—The provisional had been very poorly managed. Although the original temporary crown was screw-retained, the tooth kept fracturing due to poor clinical management. Instead of re-evaluating the cause, the clinician decided to bond the temporary with a resin cement each time it came off. This resulted in residual excess cement, now considered a major risk factor for peri-implant disease.¹³

Periodontal surgeries—Although the periodontal surgeries were thoroughly documented and carried out by highly experienced surgeons, there appeared to be little consideration for the prosthetic management of the site. Each time the surgery was carried out, the patient was instructed to use the flipper as the provisional. This likely resulted in the flipper compressing the soft issues and certainly reduced healing capability.

Provisional denture—A fourth problem concerned the management by the patient’s former dentist of problems with the removable provisional denture. Providing the guide plane severely compromised the esthetics and resulted in aggressive loss of dental hard tissues. Failure to resolve the tooth dimension added to the distress in esthetics and also eroded the patient’s confidence.

Radiographic assessment in 2009 showed the extent of the bone loss around the implant (Figure 6).

The diagnoses were as follow: 1) peri-implantitis at the maxillary left central incisor site; 2) localized periodontitis with soft-tissue papilla loss at the maxillary left lateral incisor site; and 3) loss of tooth structure (maxillary right central incisor).

The treatment options considered by the prosthodontist/periodontist were the following:

• remove the implant, graft tissue, and place another implant, or use no implant and a conventional fixed-tooth–supported restoration
• submerge the implant with a soft-tissue graft, and restore with a conventional tooth-supported restoration
• restore the implant
• use orthodontic treatment to alter the periodontal attachment levels on the adjacent natural teeth

Each of these options was then explored in depth and is described below:

Remove the implant—This option would have required that the implant be surgically removed, as it had integrated to the extent that trephination would be necessary. Because the implant head was 4.8 mm in diameter, a 5.5-mm to 6-mm trephine would be needed. Even if the head of the implant could be removed by transverse sectioning, the diameter of the implant body was still 4.1 mm and a relatively large trephine would have to be used. This would have resulted in extensive bone loss during the procedure, which would severely compromise the case. Bone grafting of such a large site would also present great challenges, especially if another implant was to be placed. The risks of such treatment were considered too high, and the treatment could even exacerbate the situation. Also, removing the implant would not address the attachment loss at the mesial of the lateral incisor, and it also had the potential to make this attachment loss greater due to the trauma of surgery.

Keep and submerge the implant—While this option was a possibility if the soft tissues could be extended over the implant, the apparent shallow implant depth, large diameter of the neck, and minimal space between adjacent teeth made this option very challenging.

Restore the implant—The patient had a high smile line, and although soft-tissue prosthetic materials are available, the clinicians determined that these materials rarely replicate the color and texture of the site and often present with substantial maintenance difficulties.

Employ orthodontic treatment—Orthodontic consideration was also given to the attachment level adjacent to the lateral incisor. The gingival height disparity between the right and left sides would allow a more esthetic result if the maxillary left lateral incisor could be extruded. This has the potential of coronally repositioning the attachment, and if healthy, it can be expected to improve the papilla between the implant and the tooth. However, the patient was advised the papilla distal to No. 10 would also move more coronally and localized crown lengthening would likely be required. This tooth could also require restoration and, as is the case in some instances, possible intentional endodontic treatment.

Ultimately, the dental team and the patient decided the most appropriate treatment would be to cover over the implant site with soft tissue and attempt to regain some of the lost papilla. The patient also resisted the orthodontic extrusion option at this time.

The problem now was determining how to accomplish this feat, which had already been unsuccessfully attempted multiple times previously.

Prosthetic evaluation found that the healing cap used in this case was a standard cap. However, if this were to be changed out in favor of a closure screw (Figure 7), the site would be more easily managed. Replacing the healing cap would result in less pressure at the papilla site, allowing the blood supply to better maintain this area; secondly, a reduced vertical dimension would assist with the soft-tissue closure.

Next, the prosthetics for the site were evaluated. Study casts were made, along with facebow records (Kois Dento-Facial Analyzer system) and occlusal records, and mounted on a semi-adjustable articulator (Panadent, www.panadent.com). The maxillary cast was measured to determine the ideal tooth dimensions (Chu Proportion Gauge, Hu-Friedy, www.hu-friedy.com) (Figure 8). The diagnostic work-up allowed an assessment of the occlusion, and the waxing gave an indication of how much tooth tissue loss had occurred on No. 8 (Figure 9). The wax cast was duplicated in stone, and a vacuum-formed stent (Copyplast, Great Lakes Orthodontics, www.greatlakesortho.com) was fabricated.

The initial soft-tissue closure therapy involved removal and replacement of the existing healing cap with a closure screw. The adjacent soft tissue was lightly de-epithelialized by using a football-shaped diamond bur. To prevent excess pressure and allow the tissues time to mature, a direct, esthetic composite provisional adhesive bridge was fabricated. This was made in two parts: Initially, the pontic was fabricated within the vacuum form shell, by using polytetrafluoroethylene (PTFE) tape (plumber’s tape) to prevent its adhering to or locking into undercuts on the adjacent teeth (Figure 10). This allowed it to be removed and adjusted carefully on the tissue surface so as to minimize contact with the tissues around the implant.

Once the ponitc was made, the healing cap was exchanged. A rubber dam was placed, the adjacent teeth etched, and the pontic bonded into place (Figure 11 and Figure 12). The site now with the smaller screw cap was left for 6 weeks to allow the tissue time to collapse and mature and enable the papilla-loss site adjacent to the lateral incisor to regain vascularity and volume. The next stage considered was surgical soft-tissue augmentation of the site. There were two main goals with this surgery: 1) to eliminate the oral communication of the implant; and 2) to increase the tissue mass in general, allowing for some semblance of a papilla between the implant and adjacent tooth. Probing depth at the mesial of the left lateral incisor was less than 2 mm. The surgery was designed so that an increased tissue mass would allow a more normal sulcus to be formed, with the hope that a more coronal epithelial attachment would result.

The composite temporary bridge was carefully removed, allowing surgical access to the underlying site (Figure 13).

The implant closure screw was removed to improve access, to be replaced later at the conclusion of the surgical procedure. Sulcular incisions were made around teeth Nos. 8 and 10, with a vertical incision at the distal of the left lateral incisor. A sharp disection was done both to the facial and palatal sides using the access through the sulcular incision as well as a peri-implant opening. The flaps were extended as necessary, and releasing incisions were made on the facial side to minimize tissue tension.

A thick connective tissue graft was harvested from the palate (Figure 14). Due to the history of mutiple graft harvesting, the palate had fiberous scar-like tissue. The graft was approximately 10 mm in width and 15 mm in height. The harvested tissue was then secured to the flap with 5-0 gut suture both at the palatal and facial sides (Figure 15). The vertical incision was then sutured using 7-0 polypropylene suture.

Immediately after the surgery, the patient returned to the prosthodontist’s office and the composite bridge was rebonded, ensuring no pressure was placed on the surgical site.

At the 2-week postoperative appointment, the patient first had the composite provisional removed so the site could be assessed (Figure 16 and Figure 17). The sutures were removed, and the bridge was again rebonded.

Three months after the surgery was completed and with the bridge having remained stable, the patient returned for evalaution. The site now had a papilla between teeth Nos. 9 and 10, the tooth form was more esthetically pleasing, and the patient had regained her confidence (Figure 18).

Now that the site was stable, a decision concerning the final restoration was needed. Options included: 1) a bonded bridge similar to the provisional; or 2) a conventional bridge. Both options were presented to the patient; however, she responded in an unexpected way. She asked that the authors use the implant, stating that her goal had always been to have the implant restored. The patient was informed that although the implant was considered functionally stable and would support a restoration, the soft tissues might not be stable. Exposing the implant might result in the loss of the tissue volume created by the surgery due to compromised blood supply, and the clinicians recommended not using it. However, both the periodontist and prosthodontist recognized that if they refused to provide the treatment as requested, the patient was likely to seek final treatment elsewhere that could result in relapse of the site.

In order to utilize the implant, it was necessary that the implant first be exposed and the healing cap removed to index and record the position. To do this again, the bonded bridge was sectioned and removed. Then a small incision to minimize vascular insult as well as preserve as much tissue volume as possible was made at the approximate site of the healing cap, which was removed (Figure 19).

At this juncture, the impressioning was an issue, as the dimension of the impression coping provided would have impinged upon the soft-tissue papilla mesial to No. 10, which was considerably larger than the surgical opening. To overcome this problem, the impression coping was carefully modified. The tissue-level implant used had an octagonal anti-rotation internal configuration with a supporting external shoulder, both of which were indexed with the impression coping. The external shoulder was removed on the coping as it was deemed too large and unnecessary on this occasion (Figure 20).

The impression of the implant site was made using conventional vinylpolysiloxane (Aquasil, DENTSPLY, www.dentsply.com) with an open-tray impression technique (Figure 21). Once the impression was made, it was decided that a provisional should be placed on the implant to evaluate how the healing would occur. Again, the standard components were deemed too large, requiring modifications to be made. An impression coping was utilized as the temporary coping, being cut down and having a composite crown bonded to it. The implant position was such that a screw-retained provisional was fabricated, with a horizontal offset that allowed for a form of platform switching (Figure 22).

One problem that ensued during the fabrication of the provisional crown was that there was no screw available for this type of modification. Therefore, a screw had to be fabricated. This was achieved by reducing the height of the impression-coping screw and cutting a slot directly into it (Figure 23). According to instructions from the periodontist, when placing the provisional crown, the papilla sites needed to remain under-contoured to avoid compressing the tissues at the papilla sites.

The site was allowed to heal and the soft tissues continued to mature. At the 3-month post-provisionalization, the soft tissues were deemed sufficiently healthy to allow for the definitive restorative work (Figure 24).

The definitive restorative phase would include restoration of the hard tooth tissue at site No. 8 and modifying the contour of No. 10, providing a longer contact point between the proposed implant crown and this tooth, thus reducing the papilla height with the aim of closing the “black triangle.” The restorations of teeth Nos. 8 and 10 were minimal partial or sectional veneers¹⁴ with conservative minimal preparations maintained with as much of an enamel periphery as possible (Figure 25). The veneers were bonded on to the teeth and the provisional replaced again to allow for any soft-tissue maturation, especially at site No. 10 (Figure 26).

The final implant crown was then fabricated. To maintain the soft-tissue emergence, a copy technique developed by Hinds was used.¹⁵ Essentially, the soft-tissue surface of the provisional crown was duplicated and transferred to a modified impression coping. This resulted in minimal changes to the site during impressioning and allowed the contours to be duplicated on the master cast (Figure 27).

The laboratory cast that was produced had a soft-tissue profile that duplicated the intraoral site. Again it was desirable to maintain the soft tissues and not compress them further. The manufacturer’s components required alteration by removal of the gold UCLA collar in a similar manner to that described for the impression copings used for making the impression and used as the provisional restoration. This was then waxed to contour and cast in a porcelain-fused-to-metal alloy, with the abutment shoulder being removed. The porcelain was baked to the opaque abutment, providing a screw-retained implant restoration, which was delivered and torqued into place (Figure 28).

The final restoration (Figure 29) exhibited good papilla form between the central incisors, though the papilla between sites Nos. 9 and 10 was still slightly deficient. The patient was informed that orthodontic extrusion would likely resolve this issue, but she felt that she had already dedicated ample time to the restoration and was very happy with the overall final result (Figure 30).

The patient emigrated to Mexico and was not seen for several years after the treatment, so limited follow-up was available. She had been instructed to maintain the area and seek professional healthcare with an office that had hygiene services and was confident in its ability to provide cleaning and maintenance of the implant site.

When she presented for routine examination 4 years after the completion of treatment, she was still pleased with the end result (Figure 31). Soft-tissue probing around the implant and adjacent teeth showed no overt signs of disease (Figure 32). Radiographic examination indicated bone levels had not changed appreciably from 4 years previously. The patient is still considering orthodontic extrusion of the lateral incisor, which would likely improve the overall soft-tissue deficiency. A small amount of soft-tissue recession had occurred mesial to the lateral incisor, and minor staining was present at the base of the veneer restoration. This was removed, and the patient was instructed to continue her maintenance program in Mexico.

There are multiple reasons why this case resulted in tissue loss around the implant. It could be argued that at the initial presentation with the horizontal tooth fracture an immediate implant should have been placed limiting the surgical interventions. However, when considering protocols for implant placement16 the amount of compromise resulting from the previous apico-ectomy both structurally and from potential infection needs to be carefully considered. Also, immediate implant placement demands primary implant stability; with an apical area of apparent poor-quality bone, the tooth extraction site socket wall must adequately stabilize the implant. The tooth in question had a wide parallel root form, which would make immediate placement more problematic.

The choice of implant type was questionable. Although the implant provided good anchorage, the neck dimension and corresponding components, unless modified, may have contributed to this failure. The need for adequate blood supply to the tissues is well known; Figure 20 and Figure 21 clearly demonstrate the need for the implant components to be modified to limit tissue pressure encroachment.

Another area of concern was the poor control of the occlusion during the temporization phase. Although the patient was considered to have an excellent occlusion, the provisional restoration fractured on multiple occasions. The use of provisional restorations remains highly recommended in order to trial the planned definitive restoration, to facilitate maturation of healing tissues, and for patient convenience,¹⁷ but this must not be done at the expense of health. This component of therapy must be given the respect it deserves. With the restoration fracturing and the crown continually being replaced, not only were the tissues being traumatized repeatedly, but there is evidence on the radiographs (Figure 4) that residual excess cement may have also contributed to bone loss around the implant and adjacent tooth site. There is now mounting evidence that excess residual cement can lead to peri-implant disease, and restorative dentists should be meticulous with their cementation protocols.^18-20

The multiple surgeries may have contributed to the further loss of tissue, and the removable partial denture may have also contributed. Understanding the implant system and the options available with regard to the cover screw on the implant would likely have helped with the surgical closure. The pressure from the poorly planned removable transitional denture on the tissues also very likely played a part. Finally, the poor design and lack of attention provided to the adjacent teeth, which resulted in an inferior esthetic outcome with the removable denture, also undoubtedly contributed to the overall failure and added to the patient’s distress.

The periodontal-prosthetic treatment that was eventually provided, which utilized a surgical and conservative restorative approach, addressed most of these issues. Although it was virtually impossible to resolve the problems encountered completely, by understanding the deficiencies of previous treatments and planning and working as a team, the clinicians were able to achieve an overall result that, although not perfect, was highly acceptable to the patient both immediately following treatment and 4 years later. An orthodontic extrusion of the left lateral incisor is (as of press time) under consideration, which would also allow for potential further improvement.

This case reported on the need to consider all aspects (surgical and restorative) when dealing with dental implants, as adverse effects can be an issue and do occur in some patients. An interdisciplinary approach with careful thought processes, utilizing advanced knowledge and conservative techniques, can be used to overcome many of these problems.

Chandur Wadhwani, BDS, MSD
Adjunct Assistant Professor
Loma Linda University School of Dentistry
Loma Linda, California
Affiliate Instructor
University of Washington School of Dentistry
Seattle, Washington
Private Practice specializing in Prosthodontics
Bellevue, Washington

Ken Akimoto, DDS, MSD Adjunct Associate Professor
University of Washington School of Dentistry
Seattle, Washington
Private Practice specializing in Periodontics
Issaquah, Washington

Joseph Yousefian, DMD, MS
Private Practice specializing in Orthodontics
Bellevue, Washington