Direct Custom Implant Impression Copings: A Method for Accurate Impression of Highly Shaped Peri-Implant Gingiva
Written by Todd R. Schoenbaum, DDS Wednesday, 14 August 2013 08:26
Implant treatment in the aesthetic zone benefits significantly from the use of well-designed screw-retained implant provisional restorations. This protocol allows the clinician and patient to evaluate the periodontal response to the implant treatment before proceeding to the definitive restorations.
Following maturation of the soft tissue around the implant and provisional (generally 3 to 6 months following the last surgical procedure), the gingiva should have attained a natural and aesthetically acceptable state. The gingiva should have a reasonable appearance to the free-gingival margin and the papilla, based on reported expectations for papilla volumes and heights.1-4
Minor modifications to the emergence profile of the abutment and the apical extent of the interproximal contact5 may need to be modified to accomplish the aesthetic goals for the treatment,6,7 but significant efforts should be made to minimize the number of connections (and disconnections) to the head of the implant.8 This will ensure that the tissue being manipulated is fully mature and at a significantly lower risk for peri-implant bone and soft-tissue loss. Generally, the subgingival emergence of the abutment should be kept as narrow as possible, while achieving the desired results.9-11 When modifications to the provisional are required to achieve the desired result, removal of the abutments should be delayed until at least 3 months following the last surgical procedure.
|Figure 1. The screw-retained implant provisional is removed from the implants. Note the highly polished, narrow subgingival area with a 2-mm |
|Figure 2. The straight-body, open-tray impression copings are quickly attached. With the screw post slightly loosened, an attempt to rotate the body is made to quickly verify that the coping is properly indexed. The screw post is then retightened.|
|Figure 3. Low viscosity, dual-polymerizing resin cement is gently injected into the area around the impression coping. (DUO-LINK [BISCO Dental Products] was used for this case.)||Figure 4. A narrow cannula tip is used to ensure that the resin reaches to the full depth of the peri-implant sulcus.|
|Figure 5. The resin is connected across the pontic site (if applicable) and polymerized. This process should be accomplished in no more than 2 minutes to prevent changes to the soft tissue. At this point the tissue contours are “frozen” in the exact positions they were in at removal of the provisional.||Figure 6. A floss bridge will act as a scaffold across which the low shrinkage resin (Pattern Resin LS [GC America]) will be incrementally built to ensure interimplant accuracy in the impression.|
|Figure 7. The floss is gently woven between the impression copings to support the resin without applying tension.||Figure 8. The completed floss-based scaffold.|
|Figure 9. Note that the soft tissue remains completely unchanged, even after several minutes without the provisional in place. Compare to Figure 2.||Figure 10. The completed resin splint will ensure accuracy of the impression. Note: space was left under the resin splint to ensure that the copings will be picked up in the impression.|
|Figure 11. The tissue surface of the impression clearly illustrates the accuracy of the direct custom implant impression coping technique.|
THE FINAL IMPRESSION
When the soft tissue has reached a satisfactory state12 or the maximum expected volume, it is time to make the final impression. The ideal cast made from the impression should be a nearly exact replica of the form of the gingiva immediately after the provisional was removed. The difficulty lies in that immediately following removal of the provisional, the papilla will begin to flatten significantly, and the subgingival emergence will occlude. The rate at which these changes happen varies, and is largely dependent on the maturity of the soft tissue and the thickness of the periodontium. In the author’s clinical experience, these changes appear to begin as early as one or 2 minutes after removal of the provisional restoration. The flattening of the gingiva has the potential to significantly compromise the aesthetic potential of the treatment, and overall predictability. If the gingiva and papilla do flatten prior to the setting of the impression material, the resulting cast will have to be modified by the technician in an attempt to restore an ideal shape to the emergence and papilla. Unfortunately, the effect these modifications will have on the stone model may differ significantly from the gingival response once the definitive restoration and abutment are delivered. This may result in open gingival embrasures (“black triangles”), unaesthetic pontic emergence, recession of the facial gingival margin, and exposure of metal abutments.
THE DIRECT CUSTOM IMPRESSION COPING TECHNIQUE
The direct custom impression coping technique13 allows the clinician to efficiently and accurately capture the mature gingival positions without flattening or remodeling. Other implant impression techniques have been widely used (including indirect pattern resin custom copings,14,15 flowable composite with closed tray copings,16 and using the provisional as a transfer coping17-19), but most involve significant time in the laboratory, extended appointment times, or duplicate provisionals.
The direct custom implant impression coping technique protocol:
- Prepare impression copings (the copings should be open-tray, and straight or narrow emergence) and appropriate driver.
- Remove implant provisional (Figure 1).
- Quickly attach impression copings and hand tighten (Figure 2).
- Loosen the screw post a quarter turn and attempt to rotate the impression body; if it will not rotate, it is likely that the coping is properly indexed.
- Retighten the screw post.
- Dry the copings and adjacent gingiva.
- Using a narrow tip, inject a dual-polymerizing resin cement (such as DUO-LINK [BISCO Dental Products]; Kerr Maxcem Elite [Kerr], RelyX Unicem 2 [3M ESPE], SpeedCEM [Ivoclar Vivadent], etc) into the emergence area around the copings and pontic receptor sites (Figures 3 to 5).
- Polymerize the resin for 20 seconds.
This technique is easily performed in less than 2 minutes; after which, the gingiva will be accurately held in the exact position it was in with the provisional in place. Radiographs should now be made to ensure that the copings are fully seated. If treatment will involve multiple adjacent or splinted implant restorations, they should be properly splinted with a low shrinkage acrylic resin (ie, Pattern Resin LS [GC America]) to maximize accuracy (Figures 6 to 10).20-23 This will ensure that the interimplant positions are as accurate as the gingival positions.
The direct custom impression coping technique is simple to perform and provides an accurate and efficient impression of the desired gingival position (Figure 11). This results in a laboratory cast that is a proper representation of the positions of the free-gingival margin, the papilla, and the subgingival emergence of the abutment. An accurate cast saves the technician the difficult task of adjusting the emergence in the laboratory with no evidence of how the soft tissue will ultimately respond.
The accuracy of the direct custom impression coping dramatically increases the predictability of implant treatment in the aesthetic zone, where the gingival aesthetics contribute significantly to the overall success of the treatment.
- 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 dental papilla. J Periodontol. 1992;63:995-996.
- Choquet V, Hermans M, Adriaenssens P, et al. Clinical and radiographic evaluation of the papilla level adjacent to single-tooth dental implants. A retrospective study in the maxillary anterior region. J Periodontol. 2001;72:1364-1371.
- Tarnow D, Elian N, Fletcher P, et al. Vertical distance from the crest of bone to the height of the interproximal papilla between adjacent implants. J Periodontol. 2003;74:1785-1788.
- Chu SJ, Tarnow DP, Tan JH, et al. Papilla proportions in the maxillary anterior dentition. Int J Periodontics Restorative Dent. 2009;29:385-393.
- Morley J, Eubank J. Macroesthetic elements of smile design. J Am Dent Assoc. 2001;132:39-45.
- LeSage BP. Improving implant aesthetics: prosthetically generated papilla through tissue modeling with composite. Pract Proced Aesthet Dent. 2006;18:257-263.
- Priest G. Esthetic potential of single-implant provisional restorations: selection criteria of available alternatives. J Esthet Restor Dent. 2006;18:326-338.
- Abrahamsson I, Berglundh T, Lindhe J. The mucosal barrier following abutment dis/reconnection. An experimental study in dogs. J Clin Periodontol. 1997;24:568-572.
- Berglundh T, Lindhe J. Dimension of the periimplant mucosa. Biological width revisited. J Clin Periodontol. 1996;23:971-973.
- Lazzara RJ, Porter SS. Platform switching: a new concept in implant dentistry for controlling postrestorative crestal bone levels. Int J Periodontics Restorative Dent. 2006;26:9-17.
- Drago C, Lazzara RJ. Guidelines for implant abutment selection for partially edentulous patients. Compend Contin Educ Dent. 2010;31:14-20, 23-24, 26-27.
- Fürhauser R, Florescu D, Benesch T, et al. Evaluation of soft tissue around single-tooth implant crowns: the pink esthetic score. Clin Oral Implants Res. 2005;16: 639-644.
- Schoenbaum TR, Han TJ. Direct custom implant impression copings for the preservation of the pontic receptor site architecture. J Prosthet Dent. 2012;107:203-206.
- Shor A, Schuler R, Goto Y. Indirect implant-supported fixed provisional restoration in the esthetic zone: fabrication technique and treatment workflow. J Esthet Restor Dent. 2008;20:82-95.
- den Hartog L, Raghoebar GM, Stellingsma K, et al. Immediate loading and customized restoration of a single implant in the maxillary esthetic zone: a clinical report. J Prosthet Dent. 2009;102:211-215.
- Polack MA. Simple method of fabricating an impression coping to reproduce peri-implant gingiva on the master cast. J Prosthet Dent. 2002;88:221-223.
- Chee WW, Cho GC, Ha S. Replicating soft tissue contours on working casts for implant restorations. J Prosthodont. 1997;6:218-220.
- Chee W, Jivraj S. Impression techniques for implant dentistry. Br Dent J. 2006;201:429-432.
- Elian N, Tabourian G, Jalbout ZN, et al. Accurate transfer of peri-implant soft tissue emergence profile from the provisional crown to the final prosthesis using an emergence profile cast. J Esthet Restor Dent. 2007;19:306-314.
- Assif D, Fenton A, Zarb G, et al. Comparative accuracy of implant impression procedures. Int J Periodontics Restorative Dent. 1992;12:112-121.
- Assif D, Marshak B, Schmidt A. Accuracy of implant impression techniques. Int J Oral Maxillofac Implants. 1996;11:216-222.
- Vigolo P, Fonzi F, Majzoub Z, et al. An evaluation of impression techniques for multiple internal connection implant prostheses. J Prosthet Dent. 2004;92:470-476.
- Lee H, So JS, Hochstedler JL, et al. The accuracy of implant impressions: a systematic review. J Prosthet Dent. 2008;100:285-291.
Dr. Schoenbaum is an assistant clinical professor in the University of California, Los Angeles (UCLA) Division of Restorative Dentistry, assistant director of the UCLA continuing education department, and the assistant director for the UCLA Center For Esthetic Dentistry. He has lectured internationally and published numerous papers on implants and aesthetics. He is a Fellow in the AGD and the American College of Dentists. Dr. Schoenbaum also maintains a private practice within the UCLA faculty group dental practice with an emphasis on aesthetics and implant prosthetics. He can be reached at (310) 267-3380 or at email@example.com.
Disclosure: Dr. Schoenbaum reports no disclosures.
- Clinical Update
- CE Articles
- Dental Materials
- Dental Medicine
- Digital Impression Technology
- Forensic Dentistry
- Geriatric Dentistry
- Infection Control
- Interdisciplinary Dentistry
- New Directions
- Practice Management
- Oral Cancer Screening
- Oral Medicine
- Oral-Systemic connection
- Pediatric Dentistry
- Pain Management
- Post-and-Core Technique
- Sleep Disorders
- Sports Dentistry
- Technique of the Week
- Treatment Planning