Greggory A. Kinzer, DDS, MSD
Several restorative options are available for managing the debilitated dentition when multiple teeth will need to be extracted. Generally, the teeth can be replaced using a removable prosthesis or some type of fixed restoration. The fixed restoration can either be supported by the remaining teeth, if the number and location of the remaining teeth are amendable, or by the use of osseointegrated implants. For patients who do not want a removable appliance as the final restoration, implants are the treatment of choice.
Traditionally, if an implant-supported restoration was desired, the required extractions were made and the patient was transitioned to the final restoration by the placement of an immediate full or partial denture. If immediate implant placement did not occur, the implants were placed after an initial healing period. The implants were then allowed to remain undisturbed for a period of 4 months in the mandible and 6 months in the maxilla to allow for osseointegration.1-3
To bypass the need for a transitional removable appliance, studies have been conducted to assess the osseointegration of immediately loaded implants.4-7 Although immediate loading protocols were first applied to the restoration of the edentulous mandible, it has also been shown to be effective in the restoration of the edentulous maxilla.8-11 When immediate implant loading is associated with fully edentulous arches, implant splinting that achieves cross-arch stabilization is needed to control the transverse forces and limit micro-movement at the implant-bone interface. The predictability of the protocol drops if primary stabilization of the implants is not achieved. The main benefits of immediate implant loading in the full arch are that it can bypass the need for an interim removable appliance and it can help support and maintain the position of the soft tissues in the esthetic zone. However, this technique can be extremely difficult in situations where significant hard/soft tissue augmentation is required.
As an alternative to the above-mentioned protocols, there is one other technique that alleviates the need of a transitional removable appliance, maintains and supports the soft tissue, allows augmentation where needed, and eliminates problems with osseointegration owing to early occlusal loading. This approach involves the selective extraction of some teeth followed by immediate implant placement. The remaining teeth are temporarily maintained to support a fixed provisional while the first set of implants is integrating. Once osseointegration of the implants is achieved, abutments can be placed on the implants and the provisional relined so that it is the implants that support the provisional. This will then allow the remaining teeth to be extracted and the second set of immediate implants to be placed. Following integration, the second set of implants can be used to support the provisional before definitive restoration with an implant-supported prosthesis. Although there are many advantages to this protocol, the main disadvantage is the extended treatment time that is required with two separate stages of implant placement.
This case will demonstrate the treatment sequencing that is necessary for sequential extraction and implant placement in a debilitated dentition. In addition it will describe a technique that can be used to transfer the emergence profile of the provisional and the resultant position of the soft tissues around the implants to the technician for fabrication of the definitive restoration.
A 66-year-old man presented with extensive restorations in the entire maxillary and mandibular posterior arch, which had been in place approximately 30 years (Figure 1A View Figure, 1B View Figure, 1C View Figure). Clinical and radiographic examination revealed generalized moderate-severe recurrent caries at the existing crown margins as well as around areas that had been secondarily patched. In addition, generalized moderate-severe bone loss was diagnosed in the maxillary and mandibular posterior. The only teeth not previously restored were the mandibular anteriors. Aside from the presence of moderate incisal attrition, no caries or bone loss was present on these teeth.
Given the severity of the caries and the localized advanced bone loss, the treatment plan was to extract all of the maxillary teeth, with the exception of teeth Nos. 9 and 10, as well as the remaining mandibular molars. Since the patient requested not to have any type of removable appliance, implants were used to replace the missing teeth. Sequential extraction and implant placement were planned to allow a sinus lift in the area of of tooth No. 3; augment (ridge-split) in the areas of teeth Nos. 5-6 and 11-12; preserve the soft tissue architecture in the area of teeth Nos. 6-7; and forgo the use of an interim partial denture. After the mounting of study models and subsequent diagnostic waxing to incorporate the desired esthetic and functional changes, all of the existing restorations on the maxillary arch were removed (Figure 2A View Figure and Figure 2B View Figure).
To leave as many strategic abutments as possible and maximize the edentulous spaces already present, it was decided that teeth Nos. 8, 13, and 14 would be extracted during the first stage of treatment and implants placed in the Nos. 5, 6, 8, 11, and 13 sites. Caries control was performed on the abutment teeth that would be maintained, and a one-piece splinted provisional restoration (Protemp™ 3 Garant™, 3M ESPE, St Paul, Minnesota) was fabricated and temporarily cemented (TempBond®, Kerr Corporation, Orange, California). The following day the patient was seen by the surgeon to extract teeth Nos. 8, 13, and 14, increase the width of the ridge in the Nos. 5-6, 11-12 areas with a ridge split, and place implants in the Nos. 5, 6, 8, 11, and 13 sites. In addition, a sinus lift was completed in the area of Nos. 3-4. At the completion of the surgical treatment, the provisional was recemented with long-term temporary cement (Fynal®, DENTSPLY Caulk, Milford, Delaware) (Figure 3 View Figure).
After 6 months of integration, the second stage of extraction and implant placement was initiated. The provisional restoration was removed and abutments were placed on the implants (Figure 4 View Figure). The provisional was then relined over the implant abutments to transfer the load from the remaining abutment teeth to the implants themselves. The patient was then seen by the surgeon to extract teeth Nos. 4, 7, and 12 and place implants in the Nos. 3, 4, 12, and 14 sites. The second molars were to remain in place to help support the provisional until the second phase of implants were ready to be loaded, at which point they were to be extracted. Abutments were placed on the second phase of implants after 6 months and the provisionals relined. At this point, specific attention was given to the subgingival contours of the provisional to support the soft tissues. In addition to finalizing the provisionals on the maxillary arch, the lower arch was also prepared and provisionalized (Figure 5 View Figure).
After verifying the esthetics and occlusion of the provisionals, the final impressions were taken. The purpose of the final impression is not only to transfer the position of the implant fixtures and the prepared teeth to the technician but also to transfer accurately the position of the soft tissue architecture and the ovate pontic receptor site in the area of No. 7. The position of the soft tissue architecture had been created by the subgingival emergence profile of the provisional restorations. Customized impression copings were fabricated to ensure collection of all the necessary information.
To fabricate the customized impression copings, the provisional restoration and temporary abutments are first removed from the mouth. The temporary abutments are attached to fixture replicas and mounted in fast set mounting stone (Figure 6A View Figure and Figure 6B View Figure). A fast-setting silicone (Mach-2®, Parkell Inc, Edgewood, New York) is then injected around the provisional restoration to capture the external contours of the gingival third of the provisional (Figure 7A View Figure and Figure 7B View Figure). Once the material has set, the provisional and temporary abutments are removed and “open tray” impression copings can be attached to the fixture replicas (Figure 8A View Figure and Figure 8B View Figure). A light-cured composite is then flowed around the impression copings and into the ovate pontic site and cured (Figure 9 View Figure). The impression copings can then be attached in the mouth. Since the subgingival contour of the customized impression coping exactly matches the contour of the provisional restoration, the soft tissues are supported throughout the entire impression-making process (Figure 10A View Figure and Figure 10B View Figure).
The remaining abutment teeth and impression copings were picked up in the final impression (Aquasil Ultra, DENTSPLY Caulk, Milford, Delaware) (Figure 11 View Figure). The customized impression copings were only fabricated for the anterior implants given the difference in depth of the anterior implants compared with the posterior implants as well as the difference in gingival architecture in the front of the mouth compared with the back. Before pouring the master cast, soft tissue replication material (Gingitech™, Ivoclar Vivadent Inc, Amherst, New York) was used to represent the gingival tissues. The direct benefit of using the customized impression copings is that the technician can then fabricate the implant abutments and final restorations without having to adjust the tissue on the master model (Figure 12 View Figure). The restorations will support the tissues just like the provisionals in the mouth as long as they are designed to intimately contact the contours of the soft tissue as captured by the customized impression copings. The final restorations consisted of customized zirconia implant abutments and all-ceramic crowns and bridges (Lava™, 3M ESPE, St Paul, Minnesota) (Figure 13 View Figure).
Upon removal of the provisional restorations, the zirconia implant abutments were seated in the mouth. The fit of the abutments was verified clinically and radiographically. Once verified, the abutments were torqued to 35 Ncm. The final restorations were seated on the abutments and the esthetics and occlusion evaluated and adjusted as needed. A mutually protected occlusion was designed. The final restorations were cemented, making sure to remove all remnants of subgingival cement (Figures 14A View Figure 14B View Figure 14C View Figure). A temporary cement (Temp-Bond® Clear, Kerr Corporation, Orange, California) was chosen to allow removal of the restorations if an abutment screw were to come loose sometime in the future.
Sequencing the extraction of teeth and placement of implants can be very beneficial. In addition to easing the transition to a fully implant-supported restoration without the need for a removable appliance, it does so without the increased risk of prematurely overloading the fixtures before osseointegration. In addition, it can also allow for augmentation in areas that require implant site development. With regard to esthetics, using a fixed provisional restoration throughout the course of treatment allows continual support of the soft tissue architecture. Being able to maintain the soft tissue scallop and transfer the information to the technician helps alleviate many potential problems and can increase the predictability of the final restorative result.
The author would like to thank Bobby L. Butler, DDS, for the surgical placement of the implants depicted herein.
1. Branemark P-I, Hansson BO, Adell R, et al. Osseointegrated implants in the treatment of the edentulous jaw. Experiences from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1-132.
2. Albrektsson T, Zarb G, Worthington P, Eriksson AR. The long-term efficacy of currently used dental implants: A review and proposed criteria for success. Int J Oral Maxillofac Impl. 1986;1(1):11-25.
3. Garber DA, Salama MA, Salama H. Immediate total tooth replacement. Compend Contin Educ Dent. 2001;22(3):210-216.
4. Sagara M, Akagawa Y, Nikai H, Tsuru H. The effects of early occlusal loading on one-stage titanium alloy implants in beagle dogs: A pilot study. J Prosthet Dent. 1993;69(3):281-288.
5. Piattelli A, Corigliano M, Scarano A, et al. Immediate loading of titanium plasmasprayed implants: An histologic analsis in monkeys. J Periodontol. 1998;69(3):321-327.
6. Balshi TJ, Wolfinger GJ. Immediate loading of Branemark implants in edentulous mandibles: A preliminary report. Implant Dent. 1997;6(2):83-88.
7. Cooper LF, Rahman A, Moriarty J, et al. Immediate mandibular rehabilitation with endosseous implants: Simultaneous extraction, implant placement and loading. Int J Oral Maxillofac Implants. 2002;17(4):517-525.
8. Tarnow DP, Emtiaz S, Classi A. Immediate loading of threaded implants at stage 1 surgery in edentulous arches. Ten consecutive case reports with 1- to 5-year data. Int J Oral Maxillofac Implants. 1997;12(3):319-324.
9. Bocklage R. Rehabilitation of the edentulous maxilla and mandible with fixed implant-supported restorations applying immediate functional loading: A treatment concept. Implant Dent. 2002;11(2):154-158.
10. Olsson M, Urde G, Andersen JB, Sennerby L. Early loading of maxillary fixed cross-arch dental prostheses supported by six or eight oxidized titanium implants: Results after 1 year of loading. Clin Implant Dent Relat Res. 2003;5 Suppl 1:81-87.
11. Balshi TJ, Wolfinger GJ. Immediate loading of dental implants in edentulous maxilla: Case study of a unique protocol. Int J Periodontics Restorative Dent. 2003;23(1):37-45.