Indications for implant-supported rehabilitation of the posterior atrophic maxilla: A multidisciplinary consensus among experts in the field utilising the modified Delphi method.

PURPOSE: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction. MATERIALS AND METHODS: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned. RESULTS: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement. CONCLUSION: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

Guided Nitinol-Retained (Smileloc) Single-Tooth Dental Restorations.

Nitinol metal alloy that changes shape according to temperature has been in clinical use at select clinics worldwide for the past 2 years and is now released for general use. The Smileloc Abutment and nitinol sleeve enable "cementless," "screwless," crown fastening that saves time and cost with the prospect of replacement of much of the present, sometimes troublesome, anthropic, soon to be anachronistic, technology.

Computer Simulation and Maxillary All-on-Four Surgery.

Maxillary all-on-four implant reconstruction requires training beyond normal dental implant training. It conjoins technical surgical acumen, anatomic and complex spatial relationship understanding, thorough awareness of dental prosthodontic principles, and excellent patient management skills. Acquisition of appropriate training to the level of competence in an era of greater patient expectations and increased vigilance for patient safety and overall quality of care is limited. Repeated purposeful practice in performing complex psychomotor tasks is of paramount importance in achieving competence. Surgical simulation may assist surgical learners to acquire familiarity with relevant anatomic variations, instrumentation, surgical techniques, and management of intraoperative and postoperative complications.

Computer Simulation Training for Mandibular All-on-Four/All-on-Three Surgery.

Mandibular all-on-4 implant reconstruction techniques are less complex than maxillary but more complex than routine dental implant surgery, requiring advanced technical skills, deeper understanding of prosthodontic principles, and more complex surgical planning. Surgical simulation may assist experienced surgeons seeking to acquire new skills through increased planning ability, improved intraspecialty communication, and enhanced technical competence. Achieving competence is different for the trainee devoted to the learning process and the practicing surgeon with limited time and balancing other roles and responsibilities. Well-constructed continuing education incorporating simulation, 3-dimensional printed models, and computer-assisted planning may offer the most efficient path to competence.

Vertical Alveolar Augmentation Using BMP-2/ACS/Allograft with Printed Titanium Shells to Establish an Early Vascular Scaffold.

Traditional reconstruction of major alveolar ridge deficiency has required autogenous cortical cancellous particulate bone grafts, often augmented with particulate allogeneic components. Now there is a new concept to consider, that of orthoalveolar form. This paradigm shift involves components of the tissue engineering triad of inductive growth factors combined with a matrix and stem cells, together with osteotomies or devices designed for space maintenance. Reported here is early experience with computer technology used to redesign deficient alveolar ridges deriving ideal alveolar-shaped bone-forms made from powdered titanium, sintered by laser at high temperature using rapid prototype technology.

Shape-Memory Retained Complete Arch Guided Implant Treatment Using Nitinol (Smileloc) Abutments.

A case report of a complete arch interim prosthesis executed using digital work flows and with guided implant surgery is presented. The novel shape-memory retained system used to retain the complete dental prosthesis is easily indexed onto the remaining dentition, thereby being both efficient and cost-effective in the short and long term.

Extra-Long Nasal Wall-Directed Dental Implants for Maxillary Complete Arch Immediate Function: A Pilot Study.

Immediate loading of maxillary denture prostheses in the context of severe bone atrophy is complicated by posterior implant placement, sometimes requiring a complex surgical approach as zygomatic or pterygoid implants. To overcome this complexity, the authors developed an extra-long (20-24 mm) 24-degree angulated platform. It was tested on 33 patients, with 24 patients immediately loaded (72.7%) for a total of 115 implants (46% nasal). All delayed loading implants osseointegrated. Eight bilateral and six unilateral sinus grafts were performed. There were no complications during the follow-up period.

Le Fort I Distraction Osteogenesis of Edentulous Maxillae Combined with Simultaneous Sinus Floor Grafting to Obtain Orthoalveolar Form for Emergence Profile Dental Implant Restorations: Report of Three Patient Treatments Followed for 12 Years.

Three edentulous maxillary patients were treated with 9- to 15-mm advances of the maxilla by Le Fort I distraction osteogenesis combined with simultaneous sinus floor autograft placement. The patients were subsequently treated with 8 implants placed in the molar, bicuspid, and canine regions for complete arch ceramo-metal fixed restorations. Anterior emergence profile esthetics was obtained in 2 patients who had high smile lines. Following final restoration, no maxillary relapse was evident, and no implants were lost. Implant bone levels were stable, although 2 implants had 3 mm of bone loss over the 12-year follow-up period.

Reduced Arch Length as a Factor for 4-Implant Immediate Function in the Maxilla: A Technical Note and Report of 39 Patients Followed for 5 Years.

PURPOSE: To determine whether maxillary arch length deficiency treated with a V-4 implant placement method is adequate for immediate functional loading during a 5-year follow-up. MATERIALS AND METHODS: Thirty-nine patients were treated with maxillary immediate function from January 3, 2011 to February 28, 2011 and followed for a period of 5 years. Arch length after implant placement was measured retrospectively around the arch from the anterior sinus wall to the contralateral anterior sinus wall in a mid-alveolar arc on the occlusal view of the preoperative computed tomogram. Eight patients with an osseous arch length shorter than 45 mm were treated with a V-4 pattern. Thirty-one patients with an arch length longer than 45 mm were treated with an M-4 placement pattern. The aim was to determine whether immediate function with a shorter arch length could be obtained on the day of surgery using a V-4 placement and whether implant stability would persist during the 5-year follow-up. Any surgical events, including lost implants, were recorded in the charts. Late follow-up was performed by panoramic films. RESULTS: During the 2-month treatment period, 39 patients (8 with V-4 placement and and 31 with M-4 placement) received maxillary treatment. The 8 patients in the V-4 group had an arch length average of 36.0 mm available for osseointegration. The 31 patients in the M-4 group had an arch length average of 56.6 mm. There were 7 implant losses (and replacements) during the 5-year follow-up, 1 in the V-4 group and 6 in the M-4 group. CONCLUSION: When the arch length bone available for osseointegration is shorter than 45 mm, a V-4 placement strategy might enable successful 4-implant fixed denture support for immediate function.

Dental extraction, immediate placement of dental implants, and immediate function.

Immediate function requires adequate implant stability. Immediate function requires prosthetic stability, particularly when multiple implants are loaded. Factors to consider for immediate implants into extraction sites are thickness of socket walls, thickness of gingival drape, optimal position of the implant, and patient factors such as hygiene and smoking cessation.

Vertical bone augmentation using recombinant bone morphogenetic protein, mineralized bone allograft, and titanium mesh: a retrospective cone beam computed tomography study.

PURPOSE: This retrospective study evaluated the use of a composite graft of recombinant human bone morphogenetic protein-2 (rhBMP-2) and particulate mineralized bone allograft protected by a titanium mesh for vertical bone augmentation. MATERIALS AND METHODS: A review of data on patients from four oral and maxillofacial surgery practices in the United States who required vertical augmentation prior to implant treatment was conducted. Vertical augmentation was accomplished with rhBMP-2 in an absorbable collagen sponge (ACS) carrier and particulate allograft. Cone beam computed tomography was used to measure vertical bone gains using this technique. RESULTS: Sixteen vertical ridge augmentation procedures were performed in 15 patients. The maximum vertical bone gains ranged from 4.4 to 16.3 mm. The average maximum vertical bone gain was 8.53 mm. The procedure allowed implant placement in all patients. Forty implants were inserted into the grafted ridges after a minimum of 6 months of healing. All implants integrated and were used for prosthetic support. CONCLUSION: This study suggests that rhBMP-2/ACS and particulate mineralized bone allograft protected by a titanium mesh offers favorable vertical bone gains to allow dental implant placement.

Imperforate titanium shell enclosing recombinant human bone morphogenetic protein-2-induced bone formation for high-profile dental implants in rabbit tibia.

PURPOSE: To evaluate the use of a nonperforated titanium occlusive device over high-profile dental implants in rabbit tibia using recombinant human bone morphogenetic protein-2 (rhBMP-2) in an absorbable collagen sponge (ACS) for augmentation grafting. MATERIALS AND METHODS: Eight New Zealand white rabbits were used for the experiment. All rabbits underwent computed tomography of the right tibia. A custom titanium shell was manufactured for each rabbit using a computer-assisted design to confine the graft. Three high-profile implants were placed in the right tibia of each rabbit; the middle implant was placed 8 mm in supracrestal fashion and the adjacent implants were placed 5 mm in supracrestal fashion. There were 4 groups (n = 2 per group): non-shell control, titanium shell only, titanium shell over buffered collagen, and titanium shell over the ACS enriched with rhBMP-2. The animals were sacrificed after 6 or 12 weeks. Histologic preparation was carried out to evaluate bone formation. RESULTS: After 6 weeks, negligible bone growth was found around the implants. After 12 weeks, there was minimal bone formation around the implants in the control group, whereas in the group treated with ACS enriched with rhBMP-2, the titanium shell was filled with mature bone, which was expressed at the implant surface, the shell's interior, and the exterior surfaces. CONCLUSION: The placement of ACS enriched with rhBMP-2 beneath an occlusive nonperforated titanium shell confining high-profile dental implants resulted in visibly more formation of mature bone.

Anterior sinus grafts for angled implant placement for severe maxillary atrophy as an alternative to zygomatic implants for full arch fixed restoration: technique and report of 5 cases.

We report on 5 cases, 4 to demonstrate the anterior sinus graft technique for angled implant placement and 1 comparison zygomatic case, all for immediate function implant restoration despite severe maxillary atrophy. The sinus graft was low volume, with less than 5 mL of bone morphogenetic protein-2/absorbable collagen sponge allograft in a 50% mixture placed against the lateral nasal wall, often in conjunction with implant placement. The importance of the technique is to simplify treatment of severe maxillary atrophy for immediate function to avoid the need for zygomatic implant placement in the vast majority of severely atrophic maxillas.

Island osteoperiosteal flap vitality when isolated from basal bone by silicone interposition: an experimental study in rabbit tibia.

PURPOSE: This study sought to confirm, through histologic evaluation, the vitality and viability of the island osteoperiosteal flap (i-flap) in a rabbit tibia model. MATERIALS AND METHODS: In four rabbits, an osteotomy was performed on the tibial aspect of the right leg. A bone flap was raised, but the periosteal attachment was kept intact. The free-floating i-flap was separated from the rest of the bone by a silicone sheet. The rabbits were to be sacrificed after 1, 2, 4, and 8 weeks and histologic samples examined. RESULTS: All surgeries were accomplished successfully; however, three animals showed fractured tibiae within a few days after surgery and were sacrificed immediately after the fractures were discovered. The fourth rabbit was sacrificed at 4 weeks. Histologic specimens showed vital new bone in the i-flap area and signs of remodeling in the transition zone and the original basal bone. CONCLUSION: The i-flap remained vital. This suggests potential for use in bone augmentation strategies, particularly for the alveolar split procedure.

Alveolar sandwich osteotomy in resorbed alveolar ridge for dental implants: a 4-year prospective study.

PURPOSE: To answer whether severe vertical alveolar defects can be resolved using the sandwich osteotomy technique with xenograft material as filler and to evaluate the predictability of this procedure. MATERIALS AND METHODS: Ten graft sites (5 mandibular and 5 maxillary) in 9 patients treated at the Department of Oral and Maxillofacial Surgery, Hadassah Medical Center, were included in the present study. The patients underwent vertical bone augmentation using the sandwich osteotomy technique filled with xenograft material. The degree of bone augmentation was analyzed clinically at surgery and 4 to 6 months later from the computed tomography images taken just before the sites had been rehabilitated using dental implant insertion. A trephine histologic analysis was performed during implantation at 1 maxillary site. RESULTS: The mean vertical bone gain in the interval between the sandwich osteotomy and implementation was 6 mm (range 4 to 10), and it remained stable after 4 to 6 months. In 2 cases, additional horizontal bone augmentation was needed. All graft sites were rehabilitated using dental implants with satisfactory results. In 3 cases, gingival porcelain was required for the final prosthesis. Histologic examination revealed vital segmentized bone and remodeling of the filled gap. CONCLUSIONS: The interpositional alveolar bone graft using xenograft filler appears to be a viable and predictable alternative to block grafting or guided bone regeneration, resulting in good final results, with substantial vertical bone gain, even for challenging cases.

Segmental alveolar split combined with dental extractions and osteotome sinus floor intrusion in posterior maxilla using BMP-2/ACS allograft for alveolar reconstruction: technical note and report of three cases.

The present report is of 3 patients who underwent a new technique for the posterior maxilla. After multiple dental extractions, the segment's alveolar was split to widen it, and the sinus floor was intruded using an osteotome to lengthen the alveolar height and then grafted with a bone morphogenetic protein-2/absorbable allograft without primary wound closure. Implant placement occurred 4 months later, followed by prosthetic restoration.

Maxillary full-arch alveolar split osteotomy with island osteoperiosteal flaps and sinus grafting using bone morphogenetic protein-2 and retrofitting for immediate loading with a provisional: surgical and prosthetic procedures and case report.

A case report and description of a new technique for bone morphogenetic protein-2 augmentation of the maxilla are provided here. Horizontal maxillary atrophy was treated with a full-arch alveolar split osteotomy combined with sinus floor intrusion. The defect was grafted with bone morphogenetic protein-2 and demineralized freeze-dried bone allograft. Nine months later, a transgingival approach was used to place dental implants and a prefabricated provisional denture. The provisional was attached to several implants and retrofitted into place following gingival sculpting to create a tooth emergence effect. To date, this patient has been followed for 2.5 years with no implant losses or bone level changes. In addition, the gingival profile appeared to be stable.

Trans-sinus dental implants, bone morphogenetic protein 2, and immediate function for all-on-4 treatment of severe maxillary atrophy.

PURPOSE: The aim of this study was to evaluate the clinical outcomes of trans-sinus dental implant placement by use of bone morphogenetic protein 2 (BMP-2) grafting and immediate functional loading by the all-on-4 scheme. PATIENTS AND METHODS: After bone reduction to create the all-on-4 shelf or because of severe maxillary atrophy and prominent sinus anatomy, 10 patients were selected to undergo trans-sinus implant placement and simultaneous BMP-2 sinus floor grafting for immediate provisional loading. Insertion torque was measured upon implant placement. Patients were followed up for at least 1 year after final restoration when either a computed tomography scan or panoramic radiograph was obtained and analyzed for the presence of trans-sinus peri-implant bone. Hounsfield units were recorded mid sinus graft. RESULTS: Of 19 trans-sinus implants, 18 remained integrated at the 1-year follow-up, for a 5.2% failure rate. All sinus grafts formed bone, with a mean of 460 Hounsfield units. Final fixed prostheses were completed for all 10 patients. CONCLUSION: Trans-sinus dental implant placement with BMP-2 grafting to gain anterior-posterior spread for immediate function by use of all-on-4 treatment appears to be a viable alternative to the use of zygomatic implants in the presence of severe maxillary atrophy.