Case 101: Restoring a Hopeless Central Incisor by Implant-Supported Crown

The case selected is an interdisciplinary case, which relates in detail, mainly to the upper front esthetic zone. The patient presented to our office with a major concern regarding the esthetic appearance of his smile. He was unhappy with the overall size and proportions of his front teeth and also had some concerns regarding the future of the left upper central incisor. His expectations were very clear from the beginning. He wanted to fill the missing upper posterior teeth as well and have an overall beautiful smile.

Medical History

Nothing relevant or significant related to his medical history.

Initial smile.
Initial smile retracted.
Initial maxillary arch.
Initial mandibular arch.

Diagnostic Findings

Extraoral and Facial Findings

  • No significant extraoral findings.
  • Good frontal symmetry.
  • Adequate tooth display at rest.
  • High smile line.

TMJ/Mandibular Range of Motion

  • No joint sounds.
  • No history of limited range of motion.
  • No history of muscle pain.

Dental Analysis

  • Canine Angle Class 1.
  • Both maxillary second premolars and first molars missing due to previous extractions.
  • No signs of wear or bruxism habits.

Intraoral Findings

  • No significant dental treatment had been performed previously, apart from the extractions on the upper jaw, root canal treatment on tooth no. 12, and a root canal treatment and crown on tooth no. 9.
  • Crowding of the lower incisors with less than ideal spacing at the anterior lower jaw.
  • Healthy gingival support.

Radiographic Review

  • Normal bone levels both in the anterior and posterior areas.
  • No evidence of decay.
  • Root canal treatment present on tooth no. 12.
  • Radiolucency at the area of the root of tooth no. 9 with evidence of split fracture and bone loss.

Diagnosis and Prognosis


  • Periodontally healthy.
  • Class 1 occlusion with crowding at the anterior lower jaw area.
  • Tooth no. 9 with vertical root fracture and bone loss as noted radiographically, tooth no. 12 previously performed root canal treatment without post and core.
  • Missing teeth nos. 3, 4, 13, and 14.


  • Good in general.
  • Tooth no. 9 hopeless.
  • Tooth no. 12 good.

Summary of Concerns

  • What prosthetic and surgical strategies should be implemented after the extraction of tooth no. 9? If implant: immediate, late or delayed implant placement?
  • What kind of a transitional prosthetic solution can be offered to the patient after the extraction and during the healing phases?
  • If a delayed placement approach is chosen, should ridge augmentation be an option in order to augment the missing peri implant structures and minimize the immediate post extraction mucosal recession and bone resorption?
  • What type of design of the implant abutment could be considered in order to support the soft tissue architecture?
  • What would be the surgical strategies in the posterior healed sites if implants are used? Open or closed sinus lift? Delayed or simultaneous implant placement?
  • In order to correct the crowding of the lower anterior incisors, will there be a need for any extraction in order to obtain the necessary space for proper alignment?

Proposed Treatment Plan

The main goal of treatment for this patient was to accomplish a fixed method of rehabilitation following the extraction of the hopeless tooth no. 9 providing optimal esthetics. For this, the surgical and prosthetic strategies were planned in order to create optimal hard and soft tissues architecture with attention given to the peri-implant tissues. The secondary goal of treatment was to improve the overall esthetics of the patient’s smile and restore the missing posterior upper teeth with a fixed rehabilitation.

Phase 1

  • Initial therapy and proper oral hygiene instructions and validation.

Phase 2

  • Insertion of implants in the maxillary posterior sites simultaneous with bilateral open sinus elevation.
  • Tooth no. 9 to be decoronated for a future extraction and immediate implant placement and augmentation procedure.
  • Provisional crown on tooth no. 8 with a cantilever in the area of tooth no. 9.

Phase 3

  • Orthodontic treatment in order to correct the crowding of the lower jaw.

Phase 4

  • Extraction of the root of tooth no. 9 with simultaneous implant placement and bone augmentation of the deficient site.

Phase 5

  • Soft tissue grafting during uncovering of the implant at site no. 9.
  • Uncovering of the buried implants in the posterior areas.

Phase 6

  • Diagnostic wax-up of the full upper arch in order to create proper esthetics with definitive ceramic restorations — crowns and veneers.
  • Minimal preparation for ceramic veneers and impression for the definitive restorations of the maxillary teeth.

Phase 7

  • Cervical Contouring Concept to be applied for the design of the implant-supported crown.
  • Definitive restorations cementation and bonding.

Active Clinical Treatment

Replacing missing teeth in the esthetic zone represents a challenge in terms of the final esthetic outcome especially in patients with a high smile line. There are a variety of techniques and approaches that can be implemented, each one with its own advantages and disadvantages, and the final decisions are usually based on the operator’s clinical experience. This patient was very clear regarding his preference for a single stand-alone restoration and the desire for an improvement of the overall smile at the end of the treatment.

Taking all this into consideration, the chosen option of replacing tooth no. 9 after extraction was an implant-supported restoration. Later in this article, the selective treatment and the clinical rationale for the decisions taken are presented.

Phase 1

Proper oral hygiene and stability of the periodontal tissues is mandatory for long-term results and maintenance, especially when dealing with implant-supported restorations.

Since the treatment also involved orthodontic therapy, proper oral hygiene maintenance by the patient throughout all the different stages of the therapy is mandatory.

Phase 2

At the posterior upper jaw edentulous sites, the decision was taken to simultaneously place implants V3 (MIS Implants, together with bilateral open sinus floor elevation. This would shorten the overall time of the treatment compared with initial sinus treatment and a delayed implantation procedure. The implants were buried in a two-stage procedure. Six months following the implants installation, the uncovering procedure was performed and two weeks later an intra-oral digital scan was taken. Two connected screw-retained zirconia crowns were fabricated and delivered on both sides, three weeks later.

In such cases the restorative technique of our choice is utilizing transmucosal multi-unit abutments connected to the conical connection implants and a screw-retained FPD on top.

However, the vertical thickness of the mucosa on top of the implant heads was less than 2mm and originally it was planned to surgically thicken it.

As the patient decided at this stage to refrain from connective tissue augmentation at these posterior sites, there was no space for intermediate transmucosal abutments and thus we used titanium bases connected directly to the implant heads.

It is also our general concept to connect adjacent implant crowns rather than have them singles for better force distribution.

However, when connecting splinted crowns on multiple implants, it should meticulously be checked for a passive fit of the splinted units as a whole, and the restorative technique is partially intra-orally (cementation of the zirconia bridge on the ti-bases) and partially chair-side.

In the anterior area, two connected provisional crowns were fabricated (nos. 8-9). At the time of insertion of the provisional crowns, tooth no. 9 was decoronated, due to the decision to perform the extraction together with an immediate implant placement and bone augmentation of the deficient site at a later appointment.

Decoronation tooth no. 9.

Commentary Related to this Phase of Treatment

The decision to perform a decoronation of tooth no. 9 and to deliver a provisional bridge nos. 8-9 before the extraction, came as a practical solution in order to facilitate the clinical surgical workflow. In this situation, at the time of extraction and immediate implant placement, the provisional restoration has been already completed and ready for use.

After a thorough clinical and a CBCT analysis of the defect around no. 9, the decision was made to perform immediate implant placement and GBR at the same treatment appointment, submerging the implant, and performing a connective tissue graft procedure at the time of uncovering.

This treatment decision was viable due to the characteristics of the defect (type 2), acceptable presented soft tissue configuration, no clinical active inflammation at the site and the presence of the interproximal bone peeks.

Phase 3

There are three indications for treating the lower crowding:

Medical: Crowding creates root proximity that causes less interproximal bone volume that might accelerate bone loss in cases of future periodontal disease. Resolving the crowding creates more interproximal bone volume.

Functional: By solving the crowding, an adequate overjet and overbite is established which creates better occlusal and structural conditions for the opposing upper incisor restorations.

Esthetic: By aligning the lower incisors, a better esthetic appearance is achieved.

Commentary Related to this Phase of Treatment

In lower crowding cases two treatment options are popular:

  1. Lower incisor extraction. This option is suitable in severe crowding and in cases where the anatomical shape of the incisors is not triangular. If triangular, black embrasure triangles are created. This would also eventually create more space and might result in an extended overjet.
  1. IPR (Interproximal Reduction). By applying IPR of 0.5mm to the front sextant, a space of up to 2.5mm to 3.5mm can be gained.
    No black triangles are created. In most cases of light to moderate crowding this is the solution of choice.

In this case, two digital setups of the options were created to evaluate the final overjet, and the IPR option was chosen and executed.

Phase 4

A surgical guide was printed based on a prosthetically driven implant placement planning (MSoft – MIS implants).

A full thickness flap was elevated in order to gain proper access to the deficient site for a GBR procedure following the insertion of the implant. Tooth no. 9 was extracted.

After the extraction and degranulation of the site, drilling for the implant placement was performed with a surgical guide template (MGUIDE, MIS implants).

A V3 implant 3.9x16mm (MIS Implants, was selected due to the benefits of this implant system, its excellent immediate stability features and triangular neck design, allowing for greater bone volume around the implant neck, and its vast biologic-based design prosthetic arsenal. In addition, the implant’s 12-degree conical connection and the prosthetic components’ fit, is conducive to enabling a strong mechanical connection and a flawless seal.

Based on the 3D plan, utilizing a surgical guide (MGuide – MIS implants), the implant was torqued to 45Ncm and positioned sub-crestaly (taking as reference the existing interproximal peeks of bone) by 7mm, taking into consideration the future connection of a transmucosal component (Connect, 4mm in height).

The implant was placed following a submerged protocol, but a healing abutment of 5mm was connected rather than a cover screw, before the GBR procedure, to further support the augmented tent-like structure.

Due to the characteristics of the defect: self-containing and the presence of the interproximal peeks of bone, it was decided to use a mixture of particulate xenograft bone and allograft material (20 – 80%) together with two absorbable membranes. One highly cross-linked (Ossix Plus, Dentsply Sirona) to confine the bone graft, and one native collagen on top of the first membrane, (Bio-gide, Geistlich) which was stabilized with pins and periosteal sutures.

A periosteal releasing incision was made to mobilize and slightly advance the flap coronally aiming for primary intention wound closure.

The provisional FPD was re-cemented after shortening the area of the pontic base, in order to avoid compression at the augmented site.

Ossix Plus membrane placement.
Bio-gide membrane placement.
Implant xray.

Commentary Related to this Phase of Treatment

Due to the magnitude of the augmentation needed, the probability that adequate primary implant stability for immediate loading might not be achieved and the satisfactory transitional FPD at the site, the decision was made to submerge the implant at this stage.

A decision was made to use a mixture of bovine bone material and allograft, based on the documented success with this type of procedure and the author’s experience.

A different approach could have been considered, i.e., autologous bone graft harvested from the adjacent area (since a full thickness flap has been elevated and access was created) and placed on the proximate contact with the implant.

Use of a membrane to confine the graft is essential because of the destruction of the facial cortical plate.

A triple membrane approach was chosen. Two (one buccally and one palataly) highly cross-linked collagen membranes (Ossix Plus) used as a true membrane which has a very slow resorption time and the tendency to ossify and integrate at the augmented area.

For better manipulation, a third native collagen membrane (Bio-gide) was used on top of the Ossix Plus membranes due to the possibility for better stabilization of the entire augmented area with pins and periosteal resorbable sutures.

Non-resorbable membranes require a second surgical intervention for their removal and have a greater risk of postsurgical exposure (and infection), which would negatively affect the success of the grafting.

Phase 5

After 6 months, uncovering of the implant no. 9, together with connective tissue grafting was performed.

Very good integration and a considerable amount of bone was obtained all around the implant due to the GBR procedure.

The healing cap was screwed out and a solid transmucosal extension abutment: 4mm in diameter and 4mm in height (Connect, MIS Implants) was connected and torqued down to 33Ncm. This transmucosal abutment offers several benefits. First, because it is a solid one-piece unit there is no screw chimney that might allow for oral contaminants passing through to the abutment-implant junction. When torqued down to 33Ncm, this conical connection provides a perfect hermetic seal with practically no micromovement between the abutment and implant and no microgap. The bone-level implant is actually transformed into a tissue-level implant where the prosthetic platform is away from the bone. Different available heights of this abutment allow for selection of the optimal prosthetic level in relation to the soft tissue regardless of the depth of the implant head. Furthermore, the narrow contour of the abutment allows for the connective tissue to heal and mature around it, providing an ultimate mucosal seal, and because the abutment is not removed after placement, repeated disruption of the soft-tissue seal during the prosthetic workflow is avoided. Finally, after the abutment is connected, the prosthetic workflow is kind to the tissue, painless to the patient, and easily controlled by the dentist.

A de-epithelized free gingival graft (FGG) was added buccally at this stage.

Uncovering of the implants in the posterior areas was also performed.

Preliminary intra-oral scanning was performed for a diagnostic wax-up of the upper arch.

Second stage implant no. 9 exposure.
Second stage connective tissue grafting.

Commentary Related to this Phase of Treatment

The decision to wait for 6 months until the uncovering was made based on the amount of bone loss present at the time of implant placement as the implant was surrounded by more than 50% of the augmentation material.

For soft tissue grafting the gold standard is an autologous tissue harvested from the palate. There are several techniques for harvesting that will result in different quality and quantity of connective tissue grafts. In this clinical situation, the aim of the connective tissue graft was to ensure proper volume and contours of the soft tissue. In order to achieve this, a high quality of dense connective tissue graft was harvested using the de-epithelized FGG technique from the posterior area of the palate. This type of graft has the potential to increase its volume through the maturation phase and occasionally thereafter. The placement of the connective tissue graft was at the base of both papillae, mesial and distal to the implant, aiming for an increase in volume of the papillae over time.

The use of a transmucosal component such as Connect has several advantages — biologic and prosthetic.

Because the prosthetic platform is 4mm away from the implant head, all of the prosthetic steps can be executed without harming the biologic width that was established during the healing period. Using such a transmucosal extension provides the flexibility of a two-piece implant system (e.g., precise positioning according to the bone anatomy, implant submergence if needed, etc) with the advantages of a tissue-level implant, which include no abutment-implant microgap next to the bone (and, therefore, no bacterial colonization of the abutment-implant junction at the bone level), no micromovement close to the bone, no tissue disruption throughout the prosthetic workflow, and the ability to clearly view and access the implant.

The height of the extension abutment is chosen according to the clinical situation, and this can be replaced if significant tissue alterations occur. In this case, because the extension abutment was never removed after connection, the abutment also adheres to the desirable demand of “one time abutment.”

Phase 6

An impression for a final design for the future restorations was made. The dental technician (Stefano Inglese MDT, Oral Design Pescina, Italy) prepared an ideal diagnostic wax-up and individual provisional crowns for the two central incisors, to be connected during the appointment of preparation and impression making of the adjacent upper maxillary teeth.

Minimally invasive preparations were made through the mock-up and impression for the final restorations were taken.

Commentary Related to this Phase of Treatment

Due to the patient’s desire to improve the overall look of his smile, a decision was taken to treat the adjacent upper maxillary teeth (nos. 5-12). Very conservative preparations were made in order to maintain almost entirely the enamel, by preparing the teeth through the final desired design- mock-up.

Phase 7

Lithium disilicate ceramic veneers and a bi-layered crown (no. 8) (e.max, Ivoclar Vivadent) were made and bonded under proper isolation with rubber dam, following the standard protocol for bonding.

A hybrid screw-retained zirconia crown with e.max veneer was made for the no. 9 implant.

The posterior implants received connected screw-retained zirconia crowns.

Commentary Related to this Phase of Treatment

For very thin ceramic veneers the use of fledsphatic ceramic material will result in excellent esthetics as well. Whenever there is a combination of substrates such as crowns, veneers and implant restorations, for the dental technician it is easier to control the optical characteristics harmony of the restorations when utilizing the same material. For this reason, the design of the implant crown was a hybrid one, having the zirconia abutment design as a prepared tooth for veneer. In this way by working with similar restorative thickness, the overall control of the color and shape is facilitated.

The design of the implant crown was made using the Cervical Contouring Concept – a model-based cervical design in order to create the ideal cervical contour of the definitive crown. An ideal wax-up was duplicated on the working model, and the cervical crown contours were marked on the plaster. Then, the wax crown was removed and the plaster between the marked line and the inner prosthetic platform was gently carved away. Thus, a smooth continuity of the cervical region, from the narrow prosthetic platform (4mm diameter) to the wider diameter of the crown as it emerges from the tissue, was achieved. Also, the implant papillae were thinned and sharpened.

This restorative concept, when referencing the traditional cervical part of an implant crown with its deep and superficial contours (also termed “critical” and “subcritical” contours, respectively) is actually composed of the pre-manufactured narrow Connect abutment as the deep contour, whereas the superficial contour is custom-made as per the cervical contouring concept. This modified cervical region at the model, based on the ideal wax-up, directs the design of the cervical contours of the actual crown. When the crown is connected intraorally the peri-implant mucosa adapts to the crown’s optimal cervical contours and matures by the crown’s superficial contour guidance.

Tooth no. 9 abutment contours.
Final contours no. 9 restoration.
Final healing tooth no. 9.

In general, around implants where the soft tissue has been grafted (especially at the base of the papillae), gingival embrasure should not be completely closed. This is due to the soft tissues’ tendency to grow with time.

The post-op intra-oral clinical picture clearly shows the papillae that were almost completely maintained due to the CTG procedure that was performed at the time of uncovering.

Retrospectively, the distal embrasure should have been even more open, to allow the papilla to grow in volume. In such cases there is a clear advantage on having the restorative option as a screw-retained crown connected to a transmucosal component. Unscrewing the crown if necessary will not create any disturbance at the implant/bone level connection due to the transmucosal component (Connect).

Definitive right side retracted maximum intercuspation.
Definitive left side retracted maximum intercuspation.
Definitive retracted maximum intercuspation.
Definitive maxillary arch.


An implant-supported restoration in the visible smile zone presents an esthetic challenge for the operating team. In order to a obtain a natural looking result, not only should the crown imitate a natural tooth, but the peri-implant envelope should look like the natural convex gingiva and mucosa of the tooth. When the restored site is deficient there are different surgical options in order to support the artificial implant and crown biologically and esthetically. This case report describes one option, where a GBR procedure with triple membranes was chosen to augment the missing bone structure simultaneously with an implant placement followed by a connective tissue graft and a proven prosthetic protocol. The selection of the different materials and techniques should always be based on valid scientific evidence as well as on the operator’s individual experience and expertise.

Dr Mirela Feraru is a team member at the Bichacho clinic in Tel Aviv, Israel.

Dr Nitzan Bichacho is a professor of prosthodontics at The Hebrew University Hadassah School of Dental Medicine in Jerusalem, Israel. He is a team member at the Bichacho clinic in Tel Aviv, Israel.

Mr Stefano Inglese owns Oral Design Dental Laboratory in Pescina (Aq) Italy.