Tunnel Access for Guided Bone Regeneration in the Maxillary Anterior. Thomas M. Johnson and Dmitry Baron

Transcription

1 Tunnel Access for Guided Bone Regeneration in the Maxillary Anterior Thomas M. Johnson and Dmitry Baron Introduction: Minimally invasive surgical techniques in periodontics, including methods for ridge augmentation, have been shown to achieve surgical goals while minimizing swelling, decreasing postoperative discomfort, and enhancing soft tissue architecture. The present case illustrates a minimally invasive guided bone regeneration technique for augmentation of a deficient alveolar ridge in the esthetic zone. Case Presentation: A 30-year-old patient received localized ridge augmentation utilizing tunnel access for guided bone regeneration with a dense polytetrafluoroethylene membrane and a freeze-dried bone allograft. The patient experienced minimal postoperative swelling and discomfort, and the procedure resulted in favorable ridge dimensions for implant placement. Conclusions: The tunnel access for guided bone regeneration presented in this case may offer advantages similar to other minimally invasive ridge augmentation techniques. Further controlled clinical study is warranted. Clin Adv Periodontics 2018;8: Key Words: Allografts; alveolar ridge augmentation; bone regeneration; minimally invasive surgical procedures; orthodontics; polytetrafluoroethylene. Background Many dental implant sites can be enhanced through bone regeneration, soft tissue augmentation, or both, and often, implant placement cannot proceed until ridge deficiency is corrected. 1 3 Guided bone regeneration (GBR) is among the most widely used methods for augmenting a deficient ridge for subsequent implant placement. 4 However, flap contraction and wound dehiscence can occur during the early postoperative period. Membrane United States Army Advanced Education Program in Periodontics, Fort Gordon, GA Department of Periodontics, Army Postgraduate Dental School, Uniformed Services University of the Health Sciences, Fort Gordon, GA Department of Periodontics, Bavaria Dental Health Activity, Stuttgart Dental Clinic, Stuttgart, Germany Received May 8, 2017; accepted July 23, 2017 doi: /cap exposure may lead to bacterial contamination, little or no bone regeneration, loss of bone height and thickness on adjoining proximal tooth surfaces, flattened papillae, and irregular soft tissue architecture. 5 7 Recently a ridge augmentation technique was introduced utilizing a remote incision, laparoscopic tunnel access to the deficient ridge, and establishment of a subperiosteal pouch without advancing a traditional mucoperiosteal flap. 8 This technique combines a xenograft with recombinant human platelet-derived growth factor (rhpdgf-bb) and requires no membrane. 8 The technique described in the present case may similarly preserve soft tissue contours and reduce risk of wound dehiscence, utilizing a nonresorbable barrier/allograft combination rather than a xenograft with rhpdgf-bb. Clinical Presentation A periodontally and systemically healthy 30-year-old white male presented June 18, 2012, to Tingay Dental Clinic, Fort Gordon, Georgia, congenitally missing teeth Clinical Advances in Periodontics, Vol. 8, No. 1, March

2 FIGURE 1 Facial view in maximum intercuspation after the orthodontic phase. Because of the relatively distal position of the maxillary central incisors and the adjacent ridge deficiency, thin bone at the distofacial line angle of tooth #9 was a concern. The gingival zeniths on the maxillary central incisors were also positioned toward the distal, creating an angular appearance rather than a smooth arc. The gingival margin at the distofacial line angle of tooth #9 was positioned approximately at the cemento enamel junction. position. The virtual implant placement exhibited adequate facial bone at the platform level. Apically, the proposed fixture protruded through the facial bone (Fig. 3). The Chief Resident (DB) discussed treatment alternatives with the patient, who elected GBR in preparation for implant placement. Vertical incisions were placed in the midline labial frenum and between teeth #11 and #12 (Fig. 4), and intrasulcular incisions were made on the immediate proximal and facial surfaces of teeth adjacent to the #10 site. A tunneling kit was used to create subperiosteal tunnel access to the deficient ridge (Fig. 5). A dense polytetrafluoroethylene (dptfe) membrane was tailored to the surgical site and placed in the tunnel access (Figs. 6 and 7), and the surgical site was thoroughly irrigated with normal saline. A midcrestal incision the width of a #15 blade was made to assure proper membrane positioning, and a 1.5-mL freeze-dried bone allograft # (FDBA) hydrated in normal saline was placed beneath the barrier. A graft syringe was used to precisely apply allograft at the crest (Fig. 8). Incisions were closed with 4-0 expanded polytetrafluoroethylene sutures (Figs. 9 and 10). The patient received postoperative analgesics as well as a 1-week course of amoxicillin (500 mg three times daily). Toothbrushing in the surgical area was withheld for 2 weeks, and the patient utilized chlorhexidine plaque control until normal oral hygiene measures could be reinstated. FIGURE 2 Occlusal view after the orthodontic phase. Tooth #6 has been moved into the #7 position, teeth #8 and #9 have been positioned for porcelain veneers according to a diagnostic wax-up, and the edentulous span between teeth #9 and #11 measured 7 mm mesiodistally at the alveolar crest. #7 and #10. A diastema was present between teeth #8 and #9. The patient reported no allergies, no medications, and no surgical history. Examination revealed a minimally restored dentition with no caries lesions. Gingiva was pink and firm generally, with periodontal probing depths ranging from 1 to 3 mm. Bleeding upon probing was virtually absent. Case Management Orthodontic treatment was used to move tooth #6 into the #7 position, optimally space teeth #8 and #9 for porcelain veneers, and create proper space in the #10 position for implant placement (Figs. 1 and 2). After the orthodontic phase, planning software was used to determine implant 3D Accuitomo 170, J. Morita, Irvine, CA. Clinical Outcomes One week following surgery, incisions were closed, and the patient reported minimal discomfort limited to the first 2 postoperative days without need for narcotic analgesics. The facial and distal gingival margins on tooth #9 were coronally positioned compared with baseline (Figs. 1 and 11). Papilla-sparing incisions were used for ø mm implant placement 7 months post-gbr. Subepithelial connective tissue graft (SCTG) augmentation and immediate provisional restoration placement were completed concomitantly (Fig. 12). Four months after implant placement, the ridge contour appeared favorable, with thick peri-implant mucosa (Fig. 13). Definitive restorations (#7 to #10 positions) are shown in Figure 14, and radiographic peri-implant bone levels at 8 months are shown in Figure 15. Discussion Minimally invasive procedures accomplish surgical goals while minimizing invasiveness, risk of untoward Salvin Tunneling Kit, Salvin Dental Specialties, Charlotte, NC. Cytoplast, Osteogenics Biomedical, Lubbock, TX. # Oragraft, Lifenet Health, Virginia Beach, VA. Ring Handle Syringe 4.5 mm, Salvin Dental Specialties. GORE-TEX (P5K17A), W.L. Gore and Associates, Newark, DE. Replace Select Tapered, Nobel Biocare, Kloten, Switzerland. 28 Clinical Advances in Periodontics, Vol. 8, No. 1, March 2018 Tunnel Guided Bone Regeneration Technique

3 FIGURE 3 Cone-beam computed tomography: sagittal view of #10 area (3a) and volume rendering (3b). In the intended implant position, facial bone thickness measured 3 mm. However, the virtual implant apex protruded through the facial cortical plate. The radiographic guide was modified slightly and converted to a surgical guide. Radiopaque material was applied to the guide at the approximate level of the gingival margin, and the virtual implant platform was placed 3.5 mm apical to this opacity. FIGURE 4 Vertical incisions in the midline labial frenum and between teeth #11 and #12 extended from the depth of the vestibule to 3 to 4 mm coronal to the mucogingival junction. outcomes, and surgical trauma In periodontics, minimally invasive techniques in the treatment of periodontitis, 9 ridge augmentation, 8,10 14 and corticotomy procedures 15 have received clinical interest. Tunneling techniques for mucogingival surgery have been shown to enhance esthetics and decrease postoperative morbidity and discomfort Reported advantages of subperiosteal tunneling techniques for ridge augmentation include decreased postoperative swelling and discomfort as well as preserved or enhanced soft tissue contours. 8,12 Tunneling techniques specifically for GBR have been described in two reports, each a case series utilizing resorbable membranes. 10,14 One report described tunnel access for GBR in the maxillary anterior. 14 However, the ultimate effect of the treatment on gingival architecture after implant restoration in the esthetic zone was not evaluated. 14 Selection of a bioabsorbable membrane in this case would have eliminated disruption of the site at membrane removal. However, the rigidity and resilience of the dptfe FIGURE 5 Intrasulcular incisions were made on the facial of teeth #9 and #11 as well as the proximal tooth surfaces adjoining the #10 area. Full-thickness reflection with periosteal elevators proceeded to establish a tunnel between the two vertical incisions. Care was taken to reflect to the alveolar crest. The gingival margin was freed and positioned coronally compared with baseline. material facilitated membrane positioning within the tunnel access. A mineralized biomaterial (FDBA) was selected to hold the overlying gingiva in a coronal position and support space maintenance under the membrane for bone formation. Surgical goals in the present case were to augment the apical ridge deficiency in the planned implant location, maintain or improve bone thickness at the line angles of adjacent teeth, and maintain or enhance gingival contours. The vertical height of bone on the teeth adjacent to a dental implant is a primary determinant of papilla height between a natural tooth and an implant-supported crown. 19 However, bone thickness in this critical area is also of paramount importance. Horizontally deficient bone at the facial line angle of a tooth adjacent to a dental implant can lead to a disharmonious angular appearance of the gingival margin, a deficient papilla, or gingival recession. In the present case, tooth #9 bordered a site of Johnson, Baron Clinical Advances in Periodontics, Vol. 8, No. 1, March

4 FIGURE 6 dptfe membrane customized to the surgical site. Ridge augmentation at the line angles of adjacent teeth was desired. FIGURE 9 Facial view of closure with nonresorbable sutures. FIGURE 7 dptfe membrane inserted through the midline labial frenum incision and positioned in the #10 area. A midcrestal incision the width of a #15 blade was made in the #10 area to assure proper membrane positioning. A membrane fixation screw or tack could have been placed through this access. In this case, membrane fixation was not used. FIGURE 10 Occlusal view upon completion of the GBR procedure. Note the enhanced alveolar ridge contour. FIGURE 11 Healing 1 week following GBR. The facial gingival margin remained coronally positioned on tooth #9. The patient reported minimal discomfort limited to the first 2 postoperative days. No swelling was evident at the 1-week assessment. FIGURE 8 FDBA placement. A graft syringe was used to precisely apply biomaterial at the crest. Biomaterial placement supported coronal positioning of the gingival margin. Note the more rounded gingival contour on tooth #9. ridge deficiency secondary to tooth agenesis. Accordingly, the potential for thin bone at the mesio-facial line angle was a concern. The technique used appeared to minimize risk of membrane exposure and resorption of critical line-angle bone. Controlled clinical study is warranted to determine if this technique consistently produces favorable clinical and patient-centered outcomes comparable with results reported by Lee Clinical Advances in Periodontics, Vol. 8, No. 1, March 2018 Tunnel Guided Bone Regeneration Technique

5 FIGURE 12 Dental implant (ø mm) placement 7 months after GBR. The tightly adherent dptfe membrane was carefully freed from the underlying tissue and removed through a small incision in the midline labial frenum. Gingival augmentation with a SCTG and immediate provisional restoration were completed at the time of implant placement (not shown). FIGURE 14 Definitive restorations 7 months after implant placement. Porcelain veneers were placed in the #7 to #9 positions, and an implant-supported crown was placed in the #10 area. FIGURE 13 The peri-implant mucosa was assessed 4 months after implant placement during preparation of tooth #6 (in the #7 position) and the maxillary central incisors for veneers. The alveolar ridge contour in the #10 area appeared favorable, and the facial peri-implant mucosa measured 3 to 4 mm in thickness. The distal papilla-sparing incision line made at implant insertion remained discernible. FIGURE 15 Periapical radiograph #10 area 8 months after implant placement exhibiting stable peri-implant bone levels located approximately at the first implant thread. Johnson, Baron Clinical Advances in Periodontics, Vol. 8, No. 1, March

6 Summary Why is this case new information? The authors could identify no other report documenting soft tissue contours after subperiosteal tunnel access for GBR. What are the keys to successful management of this case? Careful reflection with a tunneling kit appears helpful for preserving periosteum integrity and limiting surgical trauma. What are the primary limitations to success in this case? This technique appears most useful at apically located deficiencies. When significant augmentation is needed at the crest, direct access may be necessary to assure proper membrane positioning and placement of adequate biomaterial. Acknowledgments The authors thank Dr. Ronald W. Bice, United States Army Dental Health Activity, Fort Gordon, GA, for completing the orthodontics in this case as well as CPT Kerin M. Jamison, United States Army Advanced Education Program in Prosthodontics, Fort Gordon, GA, for providing the restorative treatment. The views expressed in this manuscript are those of the authors and do not necessarily reflect the official policy of the Department of Defense, Department of Army, United States Army Medical Department, Uniformed Services University of the Health Sciences, or the United States Government. The authors report no conflicts of interest related to this case report. CORRESPONDENCE Dr. Thomas M. Johnson, 320 E. Hospital Rd., Fort Gordon, GA thomas.m.johnson34.mil@mail.mil References 1. Schneider D, Grunder U, Ender A, Hämmerle CH, Jung RE. Volume gain and stability of peri-implant tissue following bone and soft tissue augmentation: 1-year results from a prospective cohort study. Clin Oral Implants Res 2011;22: Grunder U, Gracis S, Capelli M. Influence of the 3-D bone-toimplant relationship on esthetics. Int J Periodontics Restorative Dent 2005;25: Chiapasco M, Casentini P, Zaniboni M. Bone augmentation procedures in implant dentistry. 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