When Dr. P. I. Brånemark introduced his prosthetic protocol for the threaded titanium root-form endosseous dental implant in 1978, it was customary to wait 3 to 6 months before the fixtures were restored.1 This protracted period was considered essential to ensure that dental implants would develop a mature biologic bone-implant interface, a condition called osseointegration.2,3 Since these primary concepts were introduced, studies in implant dentistry have confirmed high success rates with implants that are restored with crowns placed within 48 hours after placement.4 Subsequently, concepts in implant dentistry have continued evolving, and new therapeutic modalities are emerging at an unprecedented rate, along with an impressive degree of success.5
Dental patients are demanding outcomes that are functional, highly aesthetic, and achieved in shorter periods of time than ever before. In an attempt to meet these demands, digital technologies are being developed that can allow the fabrication of an abutment and provisional crown before the implant has been placed. This article will describe a case in which just such a restoration was accomplished through the close coordination of the dental implant team: the restorative dentist, the implant surgeon, and the laboratory technician.
Diagnosis and Treatment Planning
A 33-year-old North African male presented to the restorative (lead author’s) practice with a chief complaint of partial edentulism at the No. 11 position (Figures 1 and 2). This canine tooth was congenitally missing and the patient had been made a removable space maintainer for nocturnal use as a teenager. He had an unremarkable medical history and his initial dental examination revealed no restorative needs, nor any significant periodontal or occlusal disease.
The patient was referred to the implant surgeon, Dr. James Spivey, a periodontist, for a clinical and radiographic assessment. After that appointment, subsequent discussion between the restorative dentist and implant surgeon concluded that implant placement could proceed without requiring any hard- or soft-tissue augmentation. This assessment for a successful outcome was contingent, in part, upon the implant system chosen, the diagnostic and design methods to be employed, as well as the surgical protocol that would be used. Of course, the patient’s wishes would factor into the final treatment plan formulated. The patient stated to the restorative dentist that at no point during the course of implant treatment did he want any metal showing in his mouth. Also, he would not tolerate any kind of removable prosthesis in public as he had enough difficulty adjusting to his space maintainer.
The ANKYLOS system (DENTSPLY International) was selected because of its well-documented hard and soft tissue-promoting characteristics.6 This is due mainly to its Morse taper abutment connection that has been shown to exhibit no clinically significant peri-implant bone loss after immediate provisionalization.7 The system’s design, wherein both the healing (known as “sulcus formers”) and definitive abutments are crucial to these characteristics, necessitated an immediate provisionalization procedure to fulfill the patient’s requirements as noted above. This would mean that an abutment (which would go on to be the definitive one) and a provisional crown would need to be inserted at the same visit as the implant was placed.
At this point, a dialogue between the restorative dentist and the dental laboratory technician, David Avery, began regarding the feasibility of immediate provisionalization. It was determined that a protocol could be utilized to proceed with this type of treatment whereby a CAT scan of the patient could be merged with clinical records to create a provisional crown, custom a abutment, and a surgical guide for implant placement.
In a quintessential example of how implant dentistry must be restoratively driven, these components were designed and produced in that order.
Clinical and Dental Laboratory Protocols
First, clinical records had to be obtained. Upper and lower vinyl polysiloxane (VPS) (EXAMIX NDS [GC America]) impressions, a maximum intercuspation bite, and a shade reading (ShadeVision [X-Rite]) were taken at the restorative dentist’s office, then sent to the laboratory team. While the models and articulation generated from these records were being processed at the laboratory, the above noted scan of the patient (i-CAT [Imaging Sciences International]) was also completed and sent to the dental laboratory team electronically (Figure 3).
|Figure 1. The patient’s initial presentation—retracted view.||Figure 2. The patient’s initial presentation—full smile.|
|Figure 3. The patient’s clinical i-CAT (Imaging Sciences International) scan.||Figure 4. The patient’s merged clinical and model scans.|
|Figure 5. The virtually designed provisional crown.||Figure 6. The virtually designed surgical guide.|
Master casts were obtained from the VPS impressions and a diagnostic wax-up of No. 11 was created. Two laboratory scans were accomplished utilizing the D810 scanner (3Shape). The first scan was of the master cast; the second was of the master cast including the diagnostic wax-up. The resulting STL files were sent to the oral surgeon and included in the implant software’s (SIMPLANT [DENTSPLY Implants]) surgical plan. The surgeon sent the files to DENTSPLY’s Simplant division for the fabrication of the surgical guide. This software had already been shown effective in the production of such guides.8 Simplant split the file and sent the data to DENTSPLY’s Atlantis division for the development of an Atlantis Gold Hue abutment (DENTSPLY Implants). Upon the laboratory team’s approval of the abutment design, a “core” file was returned to the laboratory. The core file provides the laboratory team with the final external contours of the abutment on the virtual model. This file allows the laboratory technician to design and mill a monolithic polymethyl methacrylate (PMMA) provisional restoration (Vericore [Whip Mix]) (Figure 4).
The completed surgical guide, surgical model, and Atlantis Gold Hue custom abutment were sent to the laboratory for confirmation of the provisional crown’s fit on the abutment and surgical cast. The restorative dentist determined that the definitive restoration would be Captek (Captek [Argen Corp]) due to his lengthy experience with these restorations and their ability to provide excellent functional, periodontal, and aesthetic results. The Atlantis Gold Hue abutment was chosen to support this restoration. (Note: The authors have documented and published numerous articles featuring the application of these materials for implant-supported restorations.)
As mentioned previously, the treatment in this case was reverse engineered, starting with the optimal orientation of the planned provisional crown as indicated on the virtual model (Figure 5). The Atlantis abutment that was to support this unit was then designed prior to creation of the surgical guide (Figure 6) that would dictate positioning of implant placement so as to accommodate the needed angulation of the custom abutment.
Simplant software analysis of the created virtual case model here used in stent production indicated that neither hard- nor soft-tissue grafting would be necessary to obtain the desired clinical outcome (Figure 7). A review of this analysis by the implant surgeon, in consultation with both the manufacturer and the laboratory technician, confirmed the initial clinical impression as noted above. With this knowledge in hand, and all needed laboratory procedures complete, the case was ready to proceed to its joint surgical and initial restorative phase.
|Figure 7. Virtual implant placement with the CAD/CAM abutment and provisional crown.||Figure 8. The CAD/CAM surgical guide in place during surgery.|
|Figure 9. The CAD/CAM abutment in place clinically.||Figure 10. The patient’s immediately postoperative presentation—full smile.|
|Figure 11. The patient’s 48-hour postoperative presentation—retracted view.||Figure 12. The patient’s 3-week postoperative presentation—retracted view.|
|Figure 13. The patient’s 5-week postoperative presentation—retracted view showing increased papillary definition.||Figure 14. A 12-week retracted view revealed further gingival margin refinement with full papillary development.|
|Figure 15. The full-smile view at 12 weeks.||Figure 16. The definitive restoration in place 6 months after placement.|
|Figure 17. A radiograph taken 6 months after placement reveals bone growth about the implant.|
The single-stage surgery was performed by the periodontist without complication. Dr. Spivey did report having some trepidation at “leaving everything up to the CAD/CAM surgical guide” (Figure 8) as he was used to working with auxiliary-fabricated stents from the restorative practice for single units that usually left some leeway as to his surgical approach. After implant placement, the prefabricated custom abutment was torqued into place (Figure 9) and the provisional crown was luted in (Figure 10). Occlusal adjustments were done for any lateral or protrusive contacts, and then the patient was given instruction on home care, including any diet and functional restrictions.
The 48-hour follow-up at the restorative doctor’s office revealed that the soft-tissue architecture around the provisional crown had already developed extensively and formed papillae joined by a naturally shaped margin (Figure 11). Such gingival maturation was typical in the restorative dentist’s experience with the ANKYLOS system, even when adjacent units are involved.9 Bone loss to the first thread is not an issue with this system, unlike others that are members of “the First Thread Club.” The patient reported satisfaction with the aesthetics and phonetics at that visit.
Subsequent follow-up appointments at 3 weeks (Figure 12), 5 weeks (Figure 13), and 12 weeks (Figures 14 and 15) (by which time final osseointegration had been confirmed) showed further gingival maturation seen around the definitive Captek restoration (Figure 16). This restoration was made according to the alternative method of fabricating single-tooth implant crowns,10 so removal of the abutment for a transfer impression and creation of a second abutment was unnecessary. It should be emphasized here that repeated removal and attachment of fixtures with dental implants has a negative effect on peri-implant tissues.11
Radiographic follow-up at 6 months after placement revealed peri-implant bone growth approaching encroachment over its shoulders, which is typical of the ANKYLOS implant system in the authors’ experiences (Figure 17).
The outcome achieved in this case graphically illustrates the advances in implant dentistry that digital technology has facilitated. The diagnostic, design, and manufacturing capabilities made available by this technology greatly enhance the scope of services that the restorative dentist, the implant surgeon, and the laboratory team can offer. However, in the end, the dental patient becomes the ultimate beneficiary, who can consider and choose between the widest array of treatment options that the dental profession has ever had in its armamentarium. These options are capable of providing increasingly excellent clinical results that can meet even the most demanding patient’s expectations.
- Brånemark PI, Zarb GA, Albrektsson T, eds. Tissue-Integrated Prostheses: Osseointegration in Clinical Dentistry. Chicago, IL: Quintessence Publishing; 1985.
- Brånemark PI, Hansson BO, Adell R, et al. Osseointegrated implants in the treatment of the edentulous jaw: experience from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1-132.
- Adell R, Lekholm U, Rockler B, et al. A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg. 1981;10:387-416.
- Ioannidou E, Doufexi A. Does loading time affect implant survival? A meta-analysis of 1,266 implants. J Periodontol. 2005;76:1252-1258.
- Kapos T, Evans C. CAD/CAM technology for implant abutments, crowns, and superstructures. Int J Oral Maxillofac Implants. 2014;29(suppl):117-136.
- Taiyeb-Ali TB, Toh CG, Siar CH, et al. Influence of abutment design on clinical status of peri-implant tissues. Implant Dent. 2009;18:438-446.
- Martin C, Thomé G, Melo AC, et al. Peri-implant bone response following immediate implants placed in the esthetic zone and with immediate provisionalization—a case series study. Oral Maxillofac Surg. 2014 Oct 23. [Epub ahead of print]
- Zhao XZ, Xu WH, Tang ZH, et al. Accuracy of computer-guided implant surgery by a CAD/CAM and laser scanning technique. Chin J Dent Res. 2014;17:31-36.
- McArdle BF. Restoring a long-edentulous maxillary ridge segment with adjacent implants. Compend Contin Educ Dent. 2014;35:518-521.
- McArdle BF, Clarizio LF. An alternative method for restoring single-tooth implants. J Am Dent Assoc. 2001;132:1269-1273.
- Goldenberg B. The conical connection: Its proven influence in obtaining consistent results preserving soft and hard tissue for the partially and fully edentulous patient. Presented at: Seacoast Esthetic Dentistry Association; May 1, 2015; Portsmouth, NH.
Disclosure: Dr. McArdle discloses that DENTSPLY Implants has supported several of his lectures in the past and paid for a continuing education couse he attended previously.
Disclosure: Dr. Spivey discloses that DENTSPLY has paid for a continuing education course he attended previously.
Disclosure: Mr. Avery is a consultant to DENTSPLY Implants and Prosthetics.