Guided Ridge Healing With Full-Arch Custom Prosthetics

Drs. Daniel Domingue and N. Cory Glenn
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Soft-tissue thickness is imperative around implants to promote long-term survival and the prevention of issues, including bone die back, peri-implantitis, pain, and even implant failure. It has been reported that a minimum of 2 mm of stable keratinized gingiva is needed circumferentially around an implant for the stability of the implant.1 These studies show there is even a direct correlation between bone loss and thin (<2 mm) keratinized tissue on the facial aspect, even when platform switching.2 There are several ways to surgically augment the soft tissue in and around these areas before delivering the final prosthetics that are all too often overlooked.3 Using tissues like Alloderm in a tunnel technique or a HumaDerm patient’s own palatal tissue in a pedicle flap, free flap, or rotated flap has been greatly successful, with well-written literature to back up these procedures.4 The above materials, when used in specific procedures, have their own unique drawbacks as well: Using Alloderm in a tunnel technique is a difficult procedure, and the material itself adds a significant cost to the overall case, while the HumaDerm procedure includes a second surgical site that adds morbidity to the case, and the collection is limited to the patient’s bioavailability.

Studies have shown that platelet-rich fibrin (PRF) supports periodontal and soft-tissue repair.5,6 The focus of these studies was to show 2 key factors in full-arch therapy: the development and shaping of keratinized tissues using the patient’s autogenous plasma-rich fibrin. The technique is easier, less expensive, and requires a low-learning-curve procedure that dramatically improves long-term success, stability, survival, and satisfaction in implant therapy.

USE OF PROVISIONALS FOR TISSUE CONTOURING
We can improve the surgical techniques for the immediate-load prosthesis to both enhance volume and create a cleansable shape in the keratinized tissue, thus improving the peri-implant conditions and the long-term stability of dental implants. Immediate-load, full-arch, fixed provisionals are well-documented in the literature with predictable long-term success rates, and, as we know, there can be a remodeling of bone following extractions.7,8 We also understand keratinized soft tissue will remodel during wound contraction and wound healing.9 A surgical suture technique in an immediate-load, full-arch provisional appropriately designed ahead of time has been proven to help augment soft tissue during the initial surgical phase reported in this article.

The ridge’s natural shape is commonly convex, and if not modified properly, the resultant final prosthesis design will be concave in shape and form, resulting in an uncleanable situation for the patient and adding to the etiology of hard- and soft-tissue deficiencies.10 This article proves corrective modification of the immediate prothesis will not only aid in the final prosthesis design but also improve conditions for long-term success in peri-implant health.

Figure 1. Bone graft around implants
following provisional conversion.
Figure 2. Platelet-rich fibrin layers placed on top of bone graft material around implants before tucking under buccal and lingual tissues.
Figure 3. Intaglio surface of an
immediate-load provisional.
Figure 4. The provisional in place before suturing.
Figure 5. Immediately following horizontal mattress suturing. Figure 6. Flat soft-tissue width/thickness healing at 12 weeks postoperative.

CLINICAL PROCESS
After implant placement, we can convert the temporary prosthesis to a fixed provisional using either multi-unit abutment temporary metal cylinders or direct-to-fixture, non-hexed metal cylinders. A provisional restoration can be designed prior to surgery with the intaglio shape convex and sitting 3 mm off the exposed mandible by utilizing a fully guided approach. Once the provisional is picked up, it should be brought to the lab to be trimmed and smoothed, to preserve the ovate intaglio surface, and highly polished, removing any voids that might trap food or plaque. While the provisional is being processed in the lab, the surgeon can add bone graft material to fill in any voids in the mandible (Figure 1). Two layers of PRF are placed on top of the bone graft material and completely cover all mandible or maxillary exposed bone as well (Figure 2). The 2 layers should be tucked under the buccal and lingual flaps by a minimum of 3 mm under the tissues. The PRF can be perforated to fit around the abutment for added fixation of the plasma membrane or laid between implants to be held down vertically by prosthetics. The smooth, ovate provisional is then delivered onto the dental implants and fully torqued into place prior to performing any suturing (Figures 3 and 4). The result is that all the PRF gets sandwiched between the bone and the ovate intaglio of the prosthesis, filling the entire 3-mm gap that was created. This enables the body to heal by secondary intention.11 Suture technique is critical for this: After the prosthesis is delivered, 2 horizontal mattress sutures should be placed on the left and right sides, starting from the most distal extension of the prosthesis to the most anterior aspect of the provisional, approximately at the midline. Start at the buccal just distal to the provisional, continue through the buccal tissue, then engage the buccal aspect of the lingual tissue. Once fully through, this tissue can move anteriorly. Engage the lingual aspect of the lingual tissue and pull through the lingual aspect of the buccal tissue before tying off. Repeat for the opposite side. No other sutures are needed unless the lingual flap moves when the patient’s tongue freely moves. If so, a single vertical mattress suture is advised at the midline. The tissue should be close to the borders of the provisional (Figure 5). The PRF should not be exposed to the oral cavity but should expand the intaglio surface and make direct contact with the provisional. No attempt is made to gain primary closure. Instead, the tissue is loosely approximated to the ideally shaped temporary. This theory is based on classic perio literature.12,13

Figure 7. Mandibular fixed case, ovate soft-tissue profile.

This concept is very common for second-stage uncovery of single implants with the goal of forcing the tissue to heal to the contours of the anatomically perfected provisional crown.14 Within this study, the ideal shape of the full-arch prosthesis is serving as a “full-arch healing abutment” and forcing the tissues to heal around the ideal contours of the fixed provisional. The result is a net gain in keratinized volume and thickness while also creating a cleansable shape on the entire ridge.

This procedure has 10 keys to success:

  1. An ovate, full-arch provisional prosthesis
  2. The initial incision extends entirely within keratinized tissue
  3. PRF covering the exposed bone is tucked both facially and lingually and fixed under the prosthesis by 3 mm on both sides
  4. Separate horizontal mattress sutures on the left and right regions of the mandible or maxilla
  5. A rigid, fixed prosthesis
  6. The prosthesis is vertically off the ridge by 3 mm to allow for PRF, sutures, and graft material
  7. Tongue movement doesn’t compromise the integrity of lingual tissues in the anterior—if there is any movement, a single vertical mattress suture is required
  8. The patient does not smoke and follows a soft/liquid diet for 2 weeks, when the sutures are to be removed
  9. Bilaterally balanced group function occlusion with no lateral excursion or protrusion contacts
  10. Cross-arch stabilization with no cantilevers greater than 10 mm functioning against a stable opposing arch
Figure 8. Maxillary fixed case, ovate soft-tissue profile.
Figure 9. Mandibular implant overdenture, thick flat profile.

CONCLUSIONS OF THIS STUDY
All patients used in this study to show the development of soft-tissue thickness around peri-implant tissues using only biological factors to promote healing, aiding in the long-term stability of peri-implant tissues, had favorable outcomes in regard to implant success rates that were similar to previous surgeries before this technique was employed.

  • Number of dental implants placed: 170
  • Number of failures: 3
  • Number of implants replaced: 2
  • Number of patients: 26
  • Success Rate: 98%

This study was designed to show how to augment thin biotype patients in both dentate ridges and edentulous ridges—all on immediate-load implants. All cases where implants were immediately loaded included both PRF covering the implants and grafting materials. We utilized mineralized cortical-cancellous, freeze-dried bone allograft (Maxxeus Dental) mixed with Fusion Bone Binder, which is composed of calcium sulphate and carboxyl methyl cellulose mixed with 3% gentamycin (Woodland Hills Pharmacy) in a 50/50 blend.

Figure 10. Soft-tissue comparison (sculpted vs healed without loaded temps). Figure 11. Sculpting.
Figure 12. Profile of the upper-arch ovate around the implant sites.

The final results of the soft-tissue profiles showed large, thick areas of keratinized tissue on the flat or concave ridges between implant platforms (Figure 6).

This technique can also be utilized in both mandibular and maxillary fixed cases with previously healed ridges (Figures 7 and 8). The authors have tried this same technique with implant-supported overdentures in secondary uncovery cases with similar results (Figure 9). There is a noticeable similarity in soft-tissue wound healing when using full-arch, custom healing abutments vs allowing the soft-tissue profile to collapse (Figures 10 and 11).

IN SUMMARY
It is a very common technique, immediately following implant placement, to pick up the full-arch provisional prosthesis in the patient’s mouth by using multi-unit abutments or direct-to-fixture, non-hexed temporary cylinders. Typically, this is done immediately after the patient is sutured. Traditional methods of obtaining primary closure prior to picking up the transitional prosthesis inherently result in a convex tissue surface and, thus, a concave and uncleanable intaglio surface on the restoration. During the healing period, the tissues remain contoured insufficiently for patient cleanability. Once it is time to take impressions to make the final long-term fixed prosthesis, there is often inadequate keratinized soft tissue to support peri-implant health. More importantly, the soft-tissue profile is convex. After impressions are sent to the lab, it is difficult for the lab team to make an ovate bridge when there is a thin, undeveloped ridge profile. When the restorative dentist delivers a concave, uncleanable prosthesis, it is imperative that the patient return for yearly removal of the prosthesis so that it and the tissues can be adequately cleaned.

Secondary grafting to achieve the desired amount of keratinized tissue only adds additional time, morbidity, and cost for the patient. Using this modified full-arch healing abutment technique (Figure 12), it is possible to achieve tremendous gains in keratinized volume and thickness while also making the shape of the gingiva far more cleansable and improving long-term stability.

There is often little concern about the soft-tissue profile on the day of surgery; this is a direct result of improper preoperative planning. By simply improving surgical techniques to deliver a proper ovate provisional, this full-arch healing abutment technique ensures adequate soft-tissue development in thickness and shape, further enhancing the long-term success of dental implant health.


References

  1. Linkevicius T, Apse P, Grybauskas S, et al. The influence of soft tissue thickness on crestal bone changes around implants: a 1-year prospective controlled clinical trial. Int J Oral Maxillofac Implants. 2009;24:712-719.
  2. Linkevicius T, Puisys A, Steigmann M, et al. Influence of vertical soft tissue thickness on crestal bone changes around implants with platform switching: a comparative clinical study. Clin Implant Dent Relat Res. 2015;17:1228-1236.
  3. Cranin AN. Implant surgery: the management of soft tissues. J Oral Implantol. 2002;28:230-237.
  4. Vignoletti F, Nunez J, Sanz M. Soft tissue wound healing at teeth, dental implants and the edentulous ridge when using barrier membranes, growth and differentiation factors and soft tissue substitutes. J Clin Periodontol. 2014;41(suppl 15):S23-S35.
  5. Miron RJ, Zucchelli G, Pikos MA, et al. Use of platelet-rich fibrin in regenerative dentistry: a systematic review. Clin Oral Investig. 2017;21:1913-1927.
  6. Miron RJ, Fujioka-Kobayashi M, Bishara M, et al. Platelet-rich fibrin and soft tissue wound healing: a systematic review. Tissue Eng Part B Rev. 2017;23:83-99.
  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;17:517-525.
  8. Srinivas B, Das P, Rana MM, et al. Wound healing and bone regeneration in postextraction sockets with and without platelet-rich fibrin. Ann Maxillofac Surg. 2018;8:28-34.
  9. Pippi R. Post-surgical clinical monitoring of soft tissue wound healing in periodontal and implant surgery. Int J Med Sci. 2017;14:721-728.
  10. Hämmerle C, Tarnow D. The etiology of hard- and soft-tissue deficiencies at dental implants: a narrative review. J Periodontol. 2018;89(suppl 1):S291-S303.
  11. Temmerman A, Cleeren GJ, Castro AB, et al. L-PRF for increasing the width of keratinized mucosa around implants: a split-mouth, randomized, controlled pilot clinical trial. J Periodontal Res. 2018;53:793-800.
  12. Aladmawy MA, Natto ZS, Steffensen B, et al. A comparison between primary and secondary flap coverage in ridge preservation procedures: a pilot randomized controlled clinical trial. Biomed Res Int. 2019;2019:7679319.
  13. Del Fabbro M, Panda S, Taschieri S. Adjunctive use of plasma rich in growth factors for improving alveolar socket healing: a systematic review. J Evid Based Dent Pract. 2019;19:166-176.
  14. González-Martín O, Lee E, Weisgold A, et al. Contour management of implant restorations for optimal emergence profiles: guidelines for immediate and delayed provisional restorations. Int J Periodontics Restorative Dent. 2020;40:61-70.

Dr. Domingue graduated from the Louisiana State University School of Dentistry and obtained his DDS degree in 2007. After dental school, he completed a 3-year advanced training at Brookdale University Hospital and Medical Center in New York City, where he served as chief resident of the dental and oral surgery department. Dr. Domingue is a member of the ADA; a former president of the Acadiana District Dental Association, American Academy of General Dentistry; and is the founder and president of the Acadiana Southern Society. Dr. Domingue currently resides in Lafayette, La, where he and his partner, Dr. Jerome Smith, work in an implant referral practice: Acadiana Dentistry. Dr. Domingue can be reached at danny@jeromesmithdds.com.

Dr. Glenn graduated from the University of Tennessee (UT) Health Science Center College of Dentistry. Following graduation, he went on to complete the Lutheran Medical Center’s advanced education in general dentistry residency at the UT Memphis branch. He is a graduate of the Georgia Maxi Course in Implant Dentistry and the American Orthodontic Society’s Comprehensive Ortho Program and is credentialed as an Associate Fellow in the American Academy of Implant Dentistry. He is also one of the founders of the online learning center Blue Sky Bio Academy. For several years, Dr. Glenn ran a private practice in Winchester, Tenn, and is now the VP of Technology for Blue Sky Bio, where he works in product and software development as well as clinical customer support. He speaks extensively on the topics of CAD/CAM, cone beam technology, guided dental implants, dental photography, digital smile design, complete dentures, and complex full-mouth rehabilitation. He can be reached at ncoryglenndds@gmail.com.

Disclosure: The authors report no disclosures.

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