March 1, 2015
by Michael Pollak, DDS
An aesthetic and functional implant supported restoration in the maxillary anterior zone is a clinical challenge. With careful patient selection and attention paid to available bone and implant positioning, a single stage surgery placing a non- submerged implant has been shown to be successful, with success rates similar to the traditional two-stage Branemark protocol. The correct three-dimensional positioning of the implant in the mesial-distal, apical-coronal and facial-lingual dimensions and proper management of the peri-implant soft tissues is required to achieve and maintain the desired emergence profile. A technique is described of customizing impression posts to prevent soft tissue collapse or distension during the impression procedure, and accurately transferring the clinical situation to the master cast. A case is presented involving extraction of a fractured central incisor, immediate implant placement and temporization, and the use of a customized transfer impression coping, to restore the tooth in an aesthetic manner.
The placement and maintenance of an aesthetic and functional implant supported restoration in the maxillary anterior is a clinical challenge. The correct three dimensional positioning of the implant in the mesial-distal, apical-coronal and facial-lingual dimensions and proper management of the peri-implant soft tissues is required to achieve and maintain the desired emergence profile.1,2 The use of customized healing abutments and/or provisional crowns can develop soft tissue contours and support and maintain the interdental papilla during the healing phases of implant therapy.3
A technique is described for customizing transfer impression posts to prevent soft tissue collapse or distension during the impression procedure, and accurately transferring the clinical situation to the master cast. The soft tissue profile around a maxillary central incisor is generally triangular in shape, whereas a stock transfer abutment coping is usually cylindrical in shape. This discrepancy does not allow the stock abutment to accurately transfer soft tissue information to the dental laboratory. Customized impression posts help minimize gingival distention or collapse during the impression process. This results in more accurate information being transferred to the master cast. A simple and cost effective technique has been described whereby the soft tissue contours can be transferred to the master cast.4-6
The anterior region of the maxilla is frequently termed the aesthetic zone due to its high visibility and influence on facial appearance.7,8 Single tooth replacement in this region can present many clinical challenges. Not only must the crown conform in contour, shade, and texture to its neighbors, but the gingiva must also be in symmetry and harmony with the adjacent tissues.9 Treatment options for replacing a missing anterior tooth include a fixed bridge, etched retained fixed dentures (Maryland Bridge), removable denture, and implant supported single tooth replacements.
Meticulous planning is necessary for immediate implant placement. The alveolus surrounding the tooth to be removed must have the bony crest no more than 3 mm. apical to the buccal gingival margin and no more than 4.5 mm apical at the interproximal height of bone to the final contact point.10 The surgical placement of the implant must be placed with consideration of the mesial/distal, apical/coronal, and buccal/palatal or lingual dimensions. Immediate implant placement is contra-indicated in patients who present with periapical infection, periodontal disease and severe bone loss, or a root configuration, which doesn’t allow primary stabilization of the implant. The ability to achieve primary stability of the implant at the initial surgery is essential. Tarnow has shown that even slight gaps between the implant and alveolar housing will succeed in growing bone to the implant, provided that the implant is able to achieve a good primary stabilization.11,12 If good primary stability of the implant can’t be achieved, micro-movements at the bone-implant interface can lead to the formation of a fibrous tissue at the implant interface, and subsequent implant failure. Placement of the implant collar should be at or slightly below the buccal crest of the alveolar bone to prevent the creation of a peri-implant pocket (and subsequent future hygiene maintenance issues) at the time of placement. Some cases require the placement to be slightly more apical in order to create the running room for proper emergence profile to be developed. Case reports are appearing in the literature of immediate implant placement and immediate temporization with acrylic crowns.13,14
A 68-year-old Caucasian male, who is a long time patient in the author’s practice presented with tooth #21 having suffered a vertical fracture below the gingival level on the lingual aspect. The coronal tooth fragment was retained by the gingival attachment. It was endodontically treated seven years earlier, and the patient elected not to crown the tooth as advised. A 1 mm diastema is present between the central incisors. Numerous wear facets and abfractions are noted, and the patient was advised on multiple occasions regarding the need for restorative and reconstructive dentistry. His TMJ’s are comfortable, with no pain, clicking, deviations or limited range of motions. He has mild-moderate generalized periodontal disease, with no pockets greater than 4 to 5 mm. A periapical film was taken, and evaluated regarding possible implant placement. As the patient has frequent dealings with the public, he didn’t want to be without a front tooth at any point in the procedure.
The patient was presented with a number of treatment options. The choices included extraction of the fractured tooth followed by replacement with a bridge utilizing #11 to #22 as abutments, a removable partial denture or extraction of the fractured tooth and replacement with an immediate implant placement and PFM. The patient refused any removable options and requested an implant in the #21 site. It was explained to the patient that only following extraction of the tooth, could the alveolus be evaluated for possible immediate implant placement, and that if the alveolar conditions were not favorable i.e. due to buccal plate fracture during the extraction, or the presence of a fenestration, that the socket would be grafted and the implant placement delayed. Consent and medical forms were completed, and any patient questions answered.
The fractured portions of the tooth were etched and bonded together using flowable resin, and adjusted to be out of occlusion (Fig. 1). Study models, face-bow records and centric relation bite registrations were taken, and the casts mounted on a Denar Combi semi-adjustable articulator. The dental laboratory was asked to fabricate a ‘suck-down stent’ to be used in fabricating a provisional crown chair-side at the extraction appointment two days later. A ‘Flipper’ acrylic denture was also fabricated, in case the situation wouldn’t allow immediate implant placement.
Surgical and Temporization Stages:
Following buccal and lingual infiltration local anesthesia was achieved (Ultracaine 1:100,000). A sulcular incision was made using a Bard-Parker #12 blade around #21, and a peritome was introduced in an apical direction into the periodontal ligament space (Fig. 2). It is very important when using the peritome to minimize trauma to the alveolar bone or surrounding tissue. Small forces, with a waiting period of 15 to 60 seconds (depending on bone density and size of periodontal ligament space) minimize possible damage to the alveolus. The use of the peritome should not apply to the facial aspect, in order to minimize damage to
the thinner bone usually present in this area. Once application of the periotome was complete and tooth mobility verified, the root was gently removed with forceps (Fig. 3). The exposed socket was degranulated and any soft tissue remnants removed with a curette. The buccal plate was evaluated using a periodontal probe, under magnification, and found to be intact (Fig. 4).
A Biohorizons 4.5 x 12 mm Tapered internal hex implant was selected for the site. The osteotomy was created in a step-wise manner using burs of increasing diameters under copious external irrigation using cooled saline. Care was taken to avoid the incisive canal (by slightly distalizing the implant’s placement). To avoid the tendency of the bur to ‘walk to the buccal’ the palatal wall was engaged approximately two thirds of the way apically by applying both apical and lateral pressure as necessary to achieve the desired implant position. Ideally, the implant position should have the implant center just palatal to the incisal edge in the cingulum position. If this is not possible, a slightly palatal position is preferable to a buccal position, and can be more easily corrected at the prosthetic stage. Apically the implant shoulder was placed 3 mm below the adjacent tooth’s CEJ, so as to maintain a shallow sulcus depth and to ensure adequate soft tissue height for correct emergence profile formation. Following the osteotomy’s preparation, the implant guide pin was reintroduced into the socket and left in place. Slight voids along the coronal facial aspects were filled with Mineross particulate bone using an amalgam plugger (Fig. 5) and gently compacted, along the facial aspect (Fig. 6). The guide pin was removed, leaving the bone particulate alongside the facial aspect. The implant was placed, trying to avoid any pressure along the buccal plate, and primary stability and position were verified (Fig. 7).
The transfer abutment was removed and replaced in the mouth using a PEEK acrylic temporary abutment (Fig. 8). A provisional crown was fabricated using a ‘suck-down stent’ fabricated by the laboratory (Fig. 9). The suck down stent was tried in over the abutment to check for adequate clearance, and the abutment adjusted as needed. A small opening was made in the stent, over the screw access hole, to allow a hex tool to access the screw hole (Figs. 10 & 11). Next the screw access opening in the PEEK temporary abutment was covered with a cotton pellet, to facilitate its location and access later on. The adjacent teeth were lubricated with Vaseline. The #21 area of the stent was loaded with Perfectemp temporary crown and bridge material (Denmat, Santa Maria, CA), seated to place and allowed to set in the mouth. While the material was setting, the screw channel was located by removing the cotton pellet, and the hex tool was reintroduced to remove the abutment screw. The temporary crown/PEEK abutment was carefully removed from the mouth, while still in its rubbery state, to help prevent the temporary from getting locked into any undercuts and then allowed to set completely. A laboratory analogue was attached to the temporary crown/abutment, and composite resin was added to create the desired emergence profile in the final restoration. Any flash or rough areas were trimmed and polished, and any voids repaired with flowable composite (Fig. 12). The temporary crown also helped to contain the bone graft and ‘seal’ the extraction socket (Fig. 13). Occlusion was checked in lateral and protrusive excursions, and adjusted so that the tooth was not in occlusion. Post-operative instructions were given, and antibiotics and analgesics prescribed prior to the patient’s dismissal. The patient was advised to avoid using the tooth when eating to avoid any micro-movement of the healing site. The patient was seen the following day, at one week, and three weeks post-operatively to evaluate healing and reconfirm that the provisional was not in occlusion. He reported no adverse symptoms and demonstrated good healing (Fig. 14). At four months, the soft tissue emergence profile and health appeared excellent and the restorative phase could commence (Fig. 15).
FIGURE 8. Biohorizons PEEK temporary abutment seated on implant.
Customized Transfer Abutment Fabrication
This technique is the same whether the provisional is made at the time of implant surgery, or during second stage uncovering of the implant. After the second stage implant recovery, or when the temporary crown and abutment is fabricated (i.e. if at the same appointment as the implant placement), the emergence contour is customized to the desired profile with either light cured composite resin or acrylic materials, and an appropriate healing time is allowed for osseointegration and soft tissue development. The healing abutment should recreate the subgingival contour of the tooth, and apply the correct pressure to the facial and interproximal tissues to support their contour and shape, and help prevent collapse. In the clinical case described, at the appointment for recording the impression, the customized healing abutment was removed from the mouth and attached to a laboratory analogue. This assembly was then embedded in silicone putty to about the level of the mid-facial. The buccal surface was marked to assist in the orientation of the post for future steps. Keeping the analogue in place within the putty, the customized healing abutment was unscrewed, and a stock impression post was attached in its place to the analogue. Customization of the impression post can be done by flowing flowable composite, pattern resin or C+B acrylic such as Perfectemp temporary crown and bridge material (Denmat, Santa Maria, CA), within the space between the stock abutment and the putty matrix, and allowing it to set, or curing it with a light source (in this case flowable resin and a curing light were used). On setting, the resin was inspected for any voids or rough areas and polished or repaired as needed (Figs. 16-21). The customised impression post was then seated back on the implant, in the mouth, and the soft tissue carefully evaluated (Figs. 22 & 23). A radiograph was taken to confirm complete seating of the impression post. Some collapse of the soft tissue can occur if the customization procedure takes a longer period of time, but the tissue should readily go back to its pre-operative state with the customized impression post. A polyvinyl siloxane impression was taken using a custom tray, and carefully evaluated. The temporary crown was reseated in the mouth. A face-bow registration and bite records were taken. An alginate impression was taken with the temporary crown in place, to assist the laboratory in duplicating the contours already worked out in the provisional. A laboratory analogue was attached to the custom impression post and reseated in the impression (Figure 24). Detailed instructions were provided to the laboratory regarding shade, shape, texture, occlusion.15-17 A master cast was poured and trimmed, and a soft tissue mask was created in the dental laboratory (Fig. 25). The definitive crown was fabricated by the laboratory.
Ten days later, the patient returned, and the provisional crown was removed and the final screw retained crown/ abutment was tried in and tightened with light finger pressure. A radiograph was taken to verify complete seating of the abutment, and aesthetics, occlusion and contacts were evaluated and verified. No anesthesia was required for the seating steps. The new crown followed the emergence contour developed by the provisional crown (Fig. 26). Once the position of the final abutment was verified by the radiograph, the screw was torqued down with a 20Ncm calibrated wrench (Fig. 17). The screw access hole was sealed with plumber’s Teflon tape, and flowable resin, which was light cured (Fig. 27). The slight diastema, which existed pre-operatively, was closed using a Bioclear diastema closure matrix (Clinical Research Dental) and Estelite Sigma composite resin (Tokuyama Dental Corp.), and the two central incisors proportions more closely matched than in the provisional stages. Occlusion was re-evaluated, and post-operative instructions included proper home care, and diet instructions such as avoidance of hard foodstuffs for a few month period to allow for transitional loading of the implant, and further bone maturation. The patient was seen the following day, the following week, and at one month for follow-up. The gingival levels are similar to the pre-operative state, and consistent with the patient’s age and gingival biotype. Both the patient and dentist were pleased with the result obtained (Fig. 28).
The anterior region of the maxilla is frequently termed the aesthetic zone due to its high visibility and influence on facial appearance. Single tooth implant replacement in this region can present many clinical challenges. Not only must the crown conform in contour, shade, and texture to its neighbors, but the gingiva must also be in symmetry and harmony with the adjacent tissues.13,14
Dental implants are becoming the most popular method of replacing lost natural dentition.18 Esthetic replacement of the natural tooth system with implants will grow increasingly more common as patients seek esthetic enhancement and/or tooth replaceme
nt of their natural dentitions.19,20 The focus of implantology over the past years has shifted from basic tooth replacement for function to include attention being paid to the aesthetic requirements of both the teeth and soft tissues surrounding them. Various protocols are being developed to ensure predictable, long lasting and esthetic implant supported restorations.21,22 Implant designs and surface treatments are changing to achieve earlier and greater bone to implant contact. Manufacturers are responding with improved abutment prosthetic designs which more closely approximate the natural crown contours, and ceramic abutments are being introduced which help prevent ‘metal show through’ in cases involving thin friable gingival tissues.
As we have learned, once a maxillary anterior tooth is extracted, collapse of the socket wall begins in a buccal to palatal direction. This is accentuated even more in a socket with a thin or non-existent buccal plate. In addition, the crestal height of the extraction socket begins to move apically. This can leave a large concavity in the buccal gingival tissue, resulting in a prosthesis that will not be symmetrical to the adjacent dentition. Grafting the socket at the time of extraction and/or immediate implant placement are methods to help minimize soft and hard tissue changes, and ensure optimum esthetics and maximum longevity of the implant.23-29 Meticulous planning is necessary for implant placement in the esthetic zone. Numerous treatment modalities have been developed for the long-term temporization and provisionalization of anterior implant cases. ‘Essex-type’ appliances allow the adjacent teeth to support the temporary prosthesis and prevent premature loading or micro-motion transfer to the implants. Orthodontic arch wires supporting a denture tooth can also result in a load-free temporary. ‘Flipper” partials can be fabricated, but must be adjusted on the intaglio and/or relined with Coe-soft liner. They should only be worn in social situations, and removed during meals and overnight to avoid premature loading of the implant.
Case reports are appearing in the literature of immediate implant placement and immediate temporization with acrylic crowns.30-32 It is important to stress that immediate implant placement does not halt the remodelling or resorptive processes associated with a tooth’s loss. The implants placement should not put too much pressure on the buccal wall of the osteotomy. Thicker buccal plates tend to undergo less remodeling.33 Case selection is very important, as; if the immediate placement and temporization procedures are pushed too far, fibrous attachment formation as opposed to osseointegration can result. This can create the possibility of failure and the need to remove/replace the implant and possibly graft the hard and soft tissues at the implant site, increasing the cost to the patient and/or doctor, increasing the number of appointments and treatment time, and decreasing the satisfaction of the patient and doctor. The clinician must be aware of the advantages and limitations of a proposed treatment and negotiate the best health-esthetic compromise for the situation, and long-term health parameters must always be evaluated). Patients will accept our recommendations regarding longer treatment and healing times if they understand that their best interests are being considered.
Successful and predictable maxillary single tooth replacement can be achieved with proper case selection and attention to both surgical and prosthetic technique. Extraction followed by immediate implant placement can allow for the preservation and maintenance of hard and soft tissues. This translates into fewer surgical appointments and lower costs to the patient, both of which have been major causes of resistance to treatment with implants. The clinician must know the advantages and limitations of a proposed treatment and negotiate the best health-esthetic compromise for the situation. The customized transfer abutment technique described is simple to implement and is an accurate method of recording the gingival contours achieved during the temporization stages. This technique easily transfers important three dimensional information to the laboratory in order to fabricate final restorations whose contours duplicate those developed in the provisional restorations.
The case reported here described the extraction of a fractured central incisor, and simultaneous implant placement. The use of a customized transfer abutment was employed. An aesthetic final result was achieved, satisfying both the patient and dentist.OH
The author wishes to thank Jay Mandel, RDT, and his talented technicians at M2 Dental Laboratory for their excellence, attention to detail and artistry in the fabrication of the prosthetics. Your efforts are greatly appreciated.
Dr. Michael Pollak graduated from the University of Toronto in 1989. He is Past-President of the Toronto Academy of Cosmetic Dentistry. He is a founding member of the Canadian Academy of Esthetic Dentistry. He is a graduate of the Misch Implant Institute, The Dawson Center for Advanced Studies, and the SUNY post-graduate program in Esthetic Dentistry. He is a Fellow in the International Congress of Oral Implantologists (I.C.O.I.). He maintains a general dental practice in Markham, Ontario, with an interest in cosmetic, restorative and implant dentistry. He can be contacted at email@example.com.
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1. Kois J. Single Immediate Implant Compendium 22(3) 215 2001
2. Saghezchi K. Replacing a Single Anterior Tooth Immediately After Extraction with a Single Implant to Preserve Interproximal Papilla and Screw-Vent Implant, and Provisionalization in the Esthetic Zone: A Case Report Implant Dentistry 12(2) 123-129 2003
3. J. Matani, S. Jambhekar, M. Kheur, S. Sethi, S. Kheur ‘Customized impression post: An innovative way for esthetic implant restorations’ Journal of Implant and Advanced Clinical Dentistry Apr 2013 pg. 13-17
4. Larry C., Breeding et al Transfer of gingival contours to a master cast J Prosthet Dent 1996, 75 : 341-343
5. Panagiota Eirini Spyropoulou et al Restoring implants in the esthetic zone after sculpting and capturing the peri-implant tissues in rest position : A clinical report J Prosthet Dent 2009 102: 345-347
6. Donitza A, Prosthetic procedures for optimal esthetics in a single tooth implant restoration : A case report Pract Periodont Aesthet Dent 2000 12(4) 347-352 Mariano A., Simple method of fabricating an impression post to reproduce peri-implant gingiva on the master cast J. Prosth Dent 2002 88 : 221-23
7. Chiche G.J. Esthetics of Anterior Fixed Prosthodontics Quintessence, Carol Stream IL 1994
8. Lombardi R.E. The Principles of Visual Perception and Their Clinical Application to Denture Esthetics J Prosthet Dent 29:358-381 1973
9. Rufenacht C.R. Fundamentals of Esthetics Quintessence, Chicago IL 1990
10. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal papilla. J Periodontal 1992, 63:995-996
11. Tarnow DP, Chu SJ, Human histologic verification of osseointegration of an immediate implant placed into a fresh extraction socket with an excessive gap distance without primary flap closure, graft, or membrane: a case report Int J Periodontics Restorative Dent. 2011:31(5):515-521
12. Stephen J, Chu DMD, Salama MA, Salama H, Garber DA, Saito H, Sarnachiaro GO, Tarnow Compendium July/August 2012 2-11
13. Dhanzajani P.J., Al-Rafee M.A. Single Tooth Implant Implant Restorations : A Retrospective Study Implant Dentistry 14(2) 125-129
14. Tepret F., Seitgoz A., Basa S. Immediately Loaded Anterior Single Tooth Implants: Two Cases Implant Dentistry 14(3) 242-245 2005
15. Haupt J. A Team Approach to Full Mouth Rejuvenation The Journal of Cosmetic Dentistry 18(1) 42-47 2002
16. Chiche G.J., Pinault A. Esthetics of Fixed Anterior Prosthodontics Quintessence 1994
17. Roberts M., Trinkner T. Communication guidelines for Achieving Aesthetic Success Signature 5(3) 18-21 1998)
18. Creughers N.H., Kreulen C.M., Snoek P.A., DeKanter R.J. A Systemic Review of Single Tooth Restorations Supported by Implants J of Dent 28(4): 209-217 2000
19. Petrungaro P.S. Blending Conventional Grafting Techniques with Current Trends in Anterior Implant Reconstruction Part II : The Use of Regenerative Membranes to Correct Ridge Defects The Journal of Cosmetic Dentistry 16(3) 30-37 2000
20. Sadoun A.P., Le Gall M.G. Periodontal Implications in Implant Treatment Planning for Aesthetic Results Pract Perio Aesth Dent 10(5) : 655-664 1998
21. Garber D.A., Belser U.C. Restorative Driven Implant Placement with Restoration Generated Site Development Compend Cont Ed Dent 16(8) 796-804 1995
22. Petrungaro P.S. Replacing the Natural Tooth System in the Aesthetic Zone: Immediate Loading and Provisionalization of Single Tooth Implants to Deliver the Foundations for Function and Esthetics The Journal of Cosmetic Dentistry 16(4) 38-44 2001
23. Sclar AG. Ridge preservation for optimum esthetics and function: The Biocol technique Postgraduate Dentistry. 1999: 6:3-11
24. Elian N,Cho SC, Froum S, Smith RB, Tarnow DP. A Simplified socket classification and repair technique. Pract Proce aesthet dent. 2007:19:99-104, quiz 106
25. Bunyaratavej P. Wang HL. Collagen membranes: a review J Periodontol. 2001: 72:215-229
26. Wang HL, Tsao YP. Mineralized bone allograft-plug socket augmentation: rationale and technique. Implant Dent. 2007:16:33-41
27. Jackson BJ, Morcos I. Socket grafting: a predictable technique for site preservation J Oral Implantol. 2007:33:353-364
28. Sclar AG. Strategies for management of single- tooth extraction sites in aesthetic implant therapy. J Oral Maxillofac Surg. 2005:62:90-105)
29. Petrungaro P.S. Bone Grafting at the Time of Extraction : A New Technique for Achieving Natural Bone and Tissue Contours in Esthetic Tooth Replacement The Journal of Cosmetic Dentistry 16(1) 30-45 2000
30. Schiroli G. Immediate Tooth Extraction, Placement of a Tapered Screw-Vent Implant, and Provisionalization in the Esthetic Zone : A Case Report Implant Dentistry 12(2) 123-129 2003
31. Drago C.L., O’Connor C. Immediate Extraction / Implant Placement , and Restoration with a Ceramic Abutment : A Case Report International Magazine of Oral Implantology 4(2) 11-16 2001
32. Zosky J.G. Shaffran A.P. Immediate Implant and Immediate Temporary Acrylic Crown in the Aesthetic Zone: A Case Report Oral Health 94(3) 69-80 2004 1)
33. Misch C. Implant Dentistry Second Ed. Quintessence Int 1998