Provisional Implants: Surgical and Prosthetic Aspects
http://www.implantoloji.info/articles/14/1/Provisional-Implants-Surgical-and-Prosthetic-Aspects/Page1.html
By JDI editor
Published on 02/11/2001
Charles A. Babbush, DDS, MScD
Director, The Dental Implant Center, Lyndhurst, Ohio.
Director, Dental Implant Research, and Clinical Professor, Case Western Reserve University, School of Dentistry, Cleveland, Ohio.
Although numerous technological advances have improved the ability of implant practitioners to successfully reconstruct dental implants, providing patients with teeth during the immediate postsurgical period has remained problematic. One solution has been the development of temporary implants. Such provisional implants eliminate the need for a tissue-borne prosthesis that may interfere with the healing of the submerged conventional implants and/or grafting material. This article describes the methodology for placing immediate provisional implants. Three alternative approaches to fabrication of the temporary prosthesis are discussed, and the results of 12 cases are reviewed.
Director, The Dental Implant Center, Lyndhurst, Ohio.
Director, Dental Implant Research, and Clinical Professor, Case Western Reserve University, School of Dentistry, Cleveland, Ohio.
Although numerous technological advances have improved the ability of implant practitioners to successfully reconstruct dental implants, providing patients with teeth during the immediate postsurgical period has remained problematic. One solution has been the development of temporary implants. Such provisional implants eliminate the need for a tissue-borne prosthesis that may interfere with the healing of the submerged conventional implants and/or grafting material. This article describes the methodology for placing immediate provisional implants. Three alternative approaches to fabrication of the temporary prosthesis are discussed, and the results of 12 cases are reviewed.
Introduction.
Charles A. Babbush, DDS, MScD
Director, The Dental Implant Center, Lyndhurst, Ohio.
Director, Dental Implant Research, and Clinical Professor, Case Western Reserve University, School of Dentistry, Cleveland, Ohio.
Over the past quarter century, dental implant reconstruction has become a highly efficient, predictable modality. The ability to accurately assess bone quality and quantity has greatly simplified the treatment-planning process. Computed tomography scanning technology with three dimensional reformatted imagery and related software, such as Sim/Plant (Columbia Scientific Inc., Columbia, MD) and Digital Radiography (Radiovisiography Trophy Inc., Danbury, CT), have added to our ever-increasing diagnostic armamentarium.
Other programs, such as Consult-Pro (Nobel Biocare, Yorba Linda, CA), have enhanced the implant practitioner’s ability to educate patients about the implant process. This, in turn, leads to a more thorough informed-consent process. Once cases are in progress, follow-up in a database can now be easily managed with software such as The Implant Tracker (Nobel Biocare).
Compromised anatomical deficiencies can now be augmented and grafted with state-of-the-art allograft materials, such as Dynagraft (GenSci, Irvine, CA), and a variety of guided bone-regeneration materials (W.L. Gore, Flagstaff, AZ). Improved instrumentation, such as the Osteoharvester (Osteomed Corp., Addison, TX), has also enabled doctors to harvest autogenous grafts with greater ease, improved benefit/risk ratios, and more favorable long-term outcomes. The ability to generate autogenous growth factors by harvesting patient blood in small (55–110 mL) batches and rapidly producing platelet concentrate with an office-based closed system (Harvest Technologies Corp., Norwell, MA) has dramatically decreased the need for second-site bone harvesting and improved the quality of the implant site and shortening overall treatment time.
Amid all this progress, certain areas have demanded further improvement. One such area relates to the understandable desire of patients to have teeth during the immediate postoperative period. To address this need, Jack Wimmer of Park Dental (Park Dental Studies, New York, NY) introduced temporary or provisional implants in the form of the Lew Screw in the 1970s. Victor Sendax later developed the Sendax Mini-Dental Implant System (U.S. Patent No. 5,749,732, Imtec Corp., Ardmore, OK), and the work of Paul Petrungaro with the Dentatus System (Dentatus AB, Hagerten, Sweden) along with that of numerous other clinicians further extended this concept.
The immediate provisional implant system (Nobel Biocare, Göteborg, Sweden) simplifies the process of delivering a stable, temporary fixed prosthesis at the time of implant placement. It eliminates the need for a temporary tissue-borne prosthesis that can damage conventional submerged implants and/or accompanying bone grafts. Instead, the immediate provisional implantsupported prosthesis removes the load from the soft tissue over the conventional implants and/or bone graft sites. This allows for improved healing and provides the patient with an esthetic, functional, provisional prosthesis.
The immediate provisional implants are designed with a 2.8-mm diameter at the shoulder and are supplied in 14-mm lengths; however, the length can easily be shortened by using a small pin cutter or a disk. Fabricated from titanium alloy for strength, the one-piece implant body is threaded and has a smooth machine finish. The design of the implant allows it to be bent at the neck to an angle of up to 45 degrees (a limit that far exceeds any foreseeable clinical requirement). Adjustment can thus be made for parallelism between one implant and another.
The abutment head has a fivedegree taper, an ideal configuration for cementable prostheses. A flat side on the abutment head facilitates proper placement and orientation of the insertion and removal instruments, transfer coping, and alignment of the analog in the master model if required.
The immediate provisional implant system contains all the instrumentation necessary for preparing the osseous receptor sites as well as inserting, removing, aligning, and achieving parallelism of the implants. Only one drill, a disposable 1.5-mm twist drill, is required for placement of the implants. The tooling also includes an insertion wrench, a hand wrench, a ratchet adapter, a ratchet arm, paralleling pins, a bending tool, a retrieval tool, and a stabilizing instrument for bending.
The immediate provisional implants are placed after the regular implants are in position. In the fullarch mandible, the manufacturer recommends the use of four or more immediate provisional implants. In the full-arch maxilla, a minimum of five immediate provisional implants is recommended. In small-segment situations, two to three immediate provisional implants should be used. Each of the immediate provisional implants should be placed between 1.5 mm and 2.5 mm from the adjacent conventional implants.
When the depth of available bone is ,14 mm or the amount of cortical bone is insufficient to provide stabilization, the immediate provisional implant may be contraindicated. Immediate provisional implants should not be used when it is not possible to place a sufficient number to provide adequate support for a temporary prosthesis. If the immediate provisional implant is shortened because of a lack of vertical bone, the bioengineering of the case should be reviewed and consideration given to inserting an additional implant( s) to add to the overall support.
Director, The Dental Implant Center, Lyndhurst, Ohio.
Director, Dental Implant Research, and Clinical Professor, Case Western Reserve University, School of Dentistry, Cleveland, Ohio.
Over the past quarter century, dental implant reconstruction has become a highly efficient, predictable modality. The ability to accurately assess bone quality and quantity has greatly simplified the treatment-planning process. Computed tomography scanning technology with three dimensional reformatted imagery and related software, such as Sim/Plant (Columbia Scientific Inc., Columbia, MD) and Digital Radiography (Radiovisiography Trophy Inc., Danbury, CT), have added to our ever-increasing diagnostic armamentarium.
Other programs, such as Consult-Pro (Nobel Biocare, Yorba Linda, CA), have enhanced the implant practitioner’s ability to educate patients about the implant process. This, in turn, leads to a more thorough informed-consent process. Once cases are in progress, follow-up in a database can now be easily managed with software such as The Implant Tracker (Nobel Biocare).
Compromised anatomical deficiencies can now be augmented and grafted with state-of-the-art allograft materials, such as Dynagraft (GenSci, Irvine, CA), and a variety of guided bone-regeneration materials (W.L. Gore, Flagstaff, AZ). Improved instrumentation, such as the Osteoharvester (Osteomed Corp., Addison, TX), has also enabled doctors to harvest autogenous grafts with greater ease, improved benefit/risk ratios, and more favorable long-term outcomes. The ability to generate autogenous growth factors by harvesting patient blood in small (55–110 mL) batches and rapidly producing platelet concentrate with an office-based closed system (Harvest Technologies Corp., Norwell, MA) has dramatically decreased the need for second-site bone harvesting and improved the quality of the implant site and shortening overall treatment time.
Amid all this progress, certain areas have demanded further improvement. One such area relates to the understandable desire of patients to have teeth during the immediate postoperative period. To address this need, Jack Wimmer of Park Dental (Park Dental Studies, New York, NY) introduced temporary or provisional implants in the form of the Lew Screw in the 1970s. Victor Sendax later developed the Sendax Mini-Dental Implant System (U.S. Patent No. 5,749,732, Imtec Corp., Ardmore, OK), and the work of Paul Petrungaro with the Dentatus System (Dentatus AB, Hagerten, Sweden) along with that of numerous other clinicians further extended this concept.
The immediate provisional implant system (Nobel Biocare, Göteborg, Sweden) simplifies the process of delivering a stable, temporary fixed prosthesis at the time of implant placement. It eliminates the need for a temporary tissue-borne prosthesis that can damage conventional submerged implants and/or accompanying bone grafts. Instead, the immediate provisional implantsupported prosthesis removes the load from the soft tissue over the conventional implants and/or bone graft sites. This allows for improved healing and provides the patient with an esthetic, functional, provisional prosthesis.
The immediate provisional implants are designed with a 2.8-mm diameter at the shoulder and are supplied in 14-mm lengths; however, the length can easily be shortened by using a small pin cutter or a disk. Fabricated from titanium alloy for strength, the one-piece implant body is threaded and has a smooth machine finish. The design of the implant allows it to be bent at the neck to an angle of up to 45 degrees (a limit that far exceeds any foreseeable clinical requirement). Adjustment can thus be made for parallelism between one implant and another.
The abutment head has a fivedegree taper, an ideal configuration for cementable prostheses. A flat side on the abutment head facilitates proper placement and orientation of the insertion and removal instruments, transfer coping, and alignment of the analog in the master model if required.
The immediate provisional implant system contains all the instrumentation necessary for preparing the osseous receptor sites as well as inserting, removing, aligning, and achieving parallelism of the implants. Only one drill, a disposable 1.5-mm twist drill, is required for placement of the implants. The tooling also includes an insertion wrench, a hand wrench, a ratchet adapter, a ratchet arm, paralleling pins, a bending tool, a retrieval tool, and a stabilizing instrument for bending.
The immediate provisional implants are placed after the regular implants are in position. In the fullarch mandible, the manufacturer recommends the use of four or more immediate provisional implants. In the full-arch maxilla, a minimum of five immediate provisional implants is recommended. In small-segment situations, two to three immediate provisional implants should be used. Each of the immediate provisional implants should be placed between 1.5 mm and 2.5 mm from the adjacent conventional implants.
When the depth of available bone is ,14 mm or the amount of cortical bone is insufficient to provide stabilization, the immediate provisional implant may be contraindicated. Immediate provisional implants should not be used when it is not possible to place a sufficient number to provide adequate support for a temporary prosthesis. If the immediate provisional implant is shortened because of a lack of vertical bone, the bioengineering of the case should be reviewed and consideration given to inserting an additional implant( s) to add to the overall support.
PLACEMENT METHODOLOGY - CASE REVIEW - SUMMARY - REFERENCES.
PLACEMENT METHODOLOGY.
Implant placement is carried out by using the disposable 1.5-mm twist drill in the regular implant handpiece with external irrigation. The burs are demarcated with laser etching and are long enough to approximate the 14.0-mm preparation in the bone.
After the initial receptor site has been created, one of the paralleling pins is positioned in the same manner used for positioning and preparing conventional implants. With each successive receptor site preparation, an additional paralleling pin is placed. Upon completion of the osseous preparations, the assembly of the insertion wrench into the ratchet arm is carried out.
The immediate provisional implant’s sterile packaging is opened, and the abutment head is placed into the insertion wrench. The implant is then carried to the osseous receptor site, aligned within it, and ratcheted into position until the implant shoulder is even with the crest of the alveolar ridge. If dense bone is encountered and the immediate provisional implant can only be partially seated, the retrieval tool may be used in conjunction with the ratchet to remove the implant. The author suggests that a 2-mm twist drill then be used to drill through the dense outer cortical bone. The implant can then be reinserted.
When all the implants have been placed, the paralleling pins can be inverted so that the wide end of each pin telescopes over the abutment head. This provides an elongated projection of the alignment of each implant relative to the others. If an alignment adjustment is needed, the bending tool in conjunction with the stabilizing tool can be used to bend the implant at the neck.
When this has been accomplished, the paralleling pins can be removed and the mucoperiosteal flaps repositioned and sutured with the suture material and design of choice. The author prefers a single interrupted or figureof- eight suture placed completely around the implant neck to evert the margin of the soft tissue. If interrupted sutures are used, these should be in as close proximity to the mesial and distal of the implant neck as possible to tightly adapt the soft tissues to this region of the implant.
When the case has been completed, attention can then be turned to fabricating the temporary prosthesis. The procedure can be carried out in one of several ways in the edentulous jaw. If the patient has an existing denture, the denture flanges can be removed and the tissue-bearing surface of the denture can be hollowed out by using appropriate acrylic-cutting burs. The transfer copings are seated on the abutments. Autopolymerizing methylmethyacrylate is then placed into the denture. When the denture is positioned over the copings, the patient is asked to bite into centric relationship. When the acrylic is set, the prosthesis is removed, excess margins are trimmed, and the denture is polished and checked for an appropriate fit. There should be no impingement on the surrounding tissues. The prosthesis can then be secured with Improv temporary cement (Nobel Biocare), or the patient can wear it as a removable appliance.
One alternative to this technique is the use of a processed acrylic type of prosthesis. This can be generated from an Omnivac (Dentiform, Harvey Lake, PA) suck-down made on a study cast of a diagnostic wax-up or duplicated from an existing prosthesis. Once again, when the case has been completed surgically and the soft tissue suturing has been finalized, autopolymerizing acrylic can be placed into the prefabricated splint. It can then be positioned over the previously placed copings, and the same method of pickup as described above can be carried out. As with the previous method, the prosthesis can be cemented or worn as a removable appliance.
A third option is the use of a direct procedure for either partially or fully edentulous patients. Once again, at the completion of the surgery, copings are placed on the implants. An impression is carried out using a lightbodied material, and the copings are picked up in the impression. A bite registration of the jaw relationship must be taken for this type of appliance. After the retrieval of the impression from the oral cavity, the immediate provisional implant analogs are placed into the copings in the impression and the master cast is fabricated. When this is done, the model is separated from the impression and mounted on a semi-adjustable articulator. The laboratory can then fabricate the prosthesis on the mounted model. When the prosthesis is completed, it can be cemented into place using Improv cement (Nobel Biocare) or it can be used as a removable appliance.
At the second stage (uncovering of the implants), the patient is anesthetized with local infiltration anesthesia. An incision is not necessary for removal of the immediate provisional implants. Instead, the ratchet arm and inserting tool are simply used in the reverse mode, and the immediate provisional implants are backed out of position.
CASE REVIEW.
As of the writing of this article, the author has completed 12 cases using a total of 53 immediate provisional implants. This series included four male and eight female patients. The average age was 59.5 years. In seven cases, the provisional implants were placed in the full-arch mandible. Five cases were full-arch maxillary reconstructions.
The average number of immediate provisional implants used per case was 4.4. The immediate provisional implants were in place for an average duration of 4.58 months. In one maxillary case (case No. 2), one immediate provisional implant was removed prematurely because of mobility and functional discomfort. One immediate provisional implant in a mandibular case (case No. 8) was osseointegrated at Stage II surgery. A small incision was made, the mucoperiosteal tissues were reflected, and the implant was cut at the crest of the ridge with a high-speed bur and handpiece. The implant body was left in place with no consequences or complications. It remained as a ridge-maintenance device. All patients are advised preoperatively that this situation can occur.
SUMMARY.
The immediate provisional implant system has made a considerable difference within the framework of the author’s practice, where increasing consumer awareness and quality-of-life issues have been evident for at least the past five years. Patients today are not willing to go without prosthetic appliances either in the immediate postoperative period or over the course of the six, twelve, or eighteen to twenty-four months that it takes to complete some of the more sophisticated and complex cases.
REFERENCES.
Implant placement is carried out by using the disposable 1.5-mm twist drill in the regular implant handpiece with external irrigation. The burs are demarcated with laser etching and are long enough to approximate the 14.0-mm preparation in the bone.
After the initial receptor site has been created, one of the paralleling pins is positioned in the same manner used for positioning and preparing conventional implants. With each successive receptor site preparation, an additional paralleling pin is placed. Upon completion of the osseous preparations, the assembly of the insertion wrench into the ratchet arm is carried out.
The immediate provisional implant’s sterile packaging is opened, and the abutment head is placed into the insertion wrench. The implant is then carried to the osseous receptor site, aligned within it, and ratcheted into position until the implant shoulder is even with the crest of the alveolar ridge. If dense bone is encountered and the immediate provisional implant can only be partially seated, the retrieval tool may be used in conjunction with the ratchet to remove the implant. The author suggests that a 2-mm twist drill then be used to drill through the dense outer cortical bone. The implant can then be reinserted.
When all the implants have been placed, the paralleling pins can be inverted so that the wide end of each pin telescopes over the abutment head. This provides an elongated projection of the alignment of each implant relative to the others. If an alignment adjustment is needed, the bending tool in conjunction with the stabilizing tool can be used to bend the implant at the neck.
When this has been accomplished, the paralleling pins can be removed and the mucoperiosteal flaps repositioned and sutured with the suture material and design of choice. The author prefers a single interrupted or figureof- eight suture placed completely around the implant neck to evert the margin of the soft tissue. If interrupted sutures are used, these should be in as close proximity to the mesial and distal of the implant neck as possible to tightly adapt the soft tissues to this region of the implant.
When the case has been completed, attention can then be turned to fabricating the temporary prosthesis. The procedure can be carried out in one of several ways in the edentulous jaw. If the patient has an existing denture, the denture flanges can be removed and the tissue-bearing surface of the denture can be hollowed out by using appropriate acrylic-cutting burs. The transfer copings are seated on the abutments. Autopolymerizing methylmethyacrylate is then placed into the denture. When the denture is positioned over the copings, the patient is asked to bite into centric relationship. When the acrylic is set, the prosthesis is removed, excess margins are trimmed, and the denture is polished and checked for an appropriate fit. There should be no impingement on the surrounding tissues. The prosthesis can then be secured with Improv temporary cement (Nobel Biocare), or the patient can wear it as a removable appliance.
One alternative to this technique is the use of a processed acrylic type of prosthesis. This can be generated from an Omnivac (Dentiform, Harvey Lake, PA) suck-down made on a study cast of a diagnostic wax-up or duplicated from an existing prosthesis. Once again, when the case has been completed surgically and the soft tissue suturing has been finalized, autopolymerizing acrylic can be placed into the prefabricated splint. It can then be positioned over the previously placed copings, and the same method of pickup as described above can be carried out. As with the previous method, the prosthesis can be cemented or worn as a removable appliance.
A third option is the use of a direct procedure for either partially or fully edentulous patients. Once again, at the completion of the surgery, copings are placed on the implants. An impression is carried out using a lightbodied material, and the copings are picked up in the impression. A bite registration of the jaw relationship must be taken for this type of appliance. After the retrieval of the impression from the oral cavity, the immediate provisional implant analogs are placed into the copings in the impression and the master cast is fabricated. When this is done, the model is separated from the impression and mounted on a semi-adjustable articulator. The laboratory can then fabricate the prosthesis on the mounted model. When the prosthesis is completed, it can be cemented into place using Improv cement (Nobel Biocare) or it can be used as a removable appliance.
At the second stage (uncovering of the implants), the patient is anesthetized with local infiltration anesthesia. An incision is not necessary for removal of the immediate provisional implants. Instead, the ratchet arm and inserting tool are simply used in the reverse mode, and the immediate provisional implants are backed out of position.
CASE REVIEW.
As of the writing of this article, the author has completed 12 cases using a total of 53 immediate provisional implants. This series included four male and eight female patients. The average age was 59.5 years. In seven cases, the provisional implants were placed in the full-arch mandible. Five cases were full-arch maxillary reconstructions.
The average number of immediate provisional implants used per case was 4.4. The immediate provisional implants were in place for an average duration of 4.58 months. In one maxillary case (case No. 2), one immediate provisional implant was removed prematurely because of mobility and functional discomfort. One immediate provisional implant in a mandibular case (case No. 8) was osseointegrated at Stage II surgery. A small incision was made, the mucoperiosteal tissues were reflected, and the implant was cut at the crest of the ridge with a high-speed bur and handpiece. The implant body was left in place with no consequences or complications. It remained as a ridge-maintenance device. All patients are advised preoperatively that this situation can occur.
SUMMARY.
The immediate provisional implant system has made a considerable difference within the framework of the author’s practice, where increasing consumer awareness and quality-of-life issues have been evident for at least the past five years. Patients today are not willing to go without prosthetic appliances either in the immediate postoperative period or over the course of the six, twelve, or eighteen to twenty-four months that it takes to complete some of the more sophisticated and complex cases.
REFERENCES.
- Lew, Isaih. The endosseous implant: Evaluations and modifications. Dent Clin North Am. 1970;14:201–213.
- Tarnow D, Froum S. A case report and histology of MTI modular transitional implants. NYU College of Dentistry Bulletin. May 1996; abstract.
- Ravasini G, Ugolini G, Della Turca S, et al. Protocollo operativo per l’utillizo di implanti provisory immediate (Mini- Transitional Implant–MTI). Dialog: Rivista Pratica per il Team Odontoiatrico. 1996; 1:2–6.
- Gottehrer NR, Singer G. Full team approach for provisional stabilization of the edentulous implant patient. Dent Today. 1996;15:10–13.
- Petrungaro PS. Fixed temporization and bone-augmented ridge stabilization with transitional implants. Pract Periodontics Aesthet Dent. 1997;9:1071–1078.
- Froum S, Emetiaz S, Bloom MJ. The use of transitional implants for immediate fixed temporary prosthesis in cases of implant restorations. Pract Periodontics Aesthet Dent. 1998;10:737–746.
- Petrungaro PS, Smilanich MD, Adams TJ. Altering concepts of implantology for the 21st century, Contemp Esthet Restor Pract. 1999;3:30–38.
- Petrungaro PS, Smilanich MD. Use of modular transitional implants in the partially edentulous patient. Contemp Esthet Restorative Pract. 1999;3:50–62.
- Petrungaro PS. Transitional phase: patient management with transitional implants. In: Babbush CA, ed. Dental Implants: The Art and Science. St. Louis, MO: CV Mosby; 2001. 403–420.
- Schuppan K. Temporary retention element for immediate prosthetic reconstruction. Lecture presented at: International Team Day, Nobel Biocare; September 18–19, 1998; London.
- Schuppan K. Immediate provisional implant therapy. Global Forum, Nobel Biocare International Newsletter. 2000;13:7.
- Babbush CA. Immediate extraction, immediate implants, immediate load with immediate provisional implants. Lecture presented at: ICOI World Congress; October, 2000; Berlin.
- Babbush CA. Immediate extraction, immediate implants, immediate load with immediate provisional implants. Lecture presented at: Annual Meeting of the American Association of Oral and Maxillofacial Surgery; September, 2000; San Francisco, CA.