Dental Implants and Onlay Bone Grafts in the Anterior Maxilla: Analysis of Clinical Outcome (*)

Purpose: Loss of alveolar bone in the anterior maxilla may preclude implant or compromise positioning and thus diminish the final esthetic result of restoration. Bone augmentation can overcome such difficulties but may affect osseointegration. The aim of this study was to report the outcome of buccal onlay bone grafting in the anterior maxilla in routine dental implant practice.
Materials and Methods: Seventeen consecutive patients (12 men and 5 women, mean age 31.4 years) received autogenous bone grafts from the mandibular symphysis to the anterior maxilla. A total of 35 Brånemark System MK II implants were placed in grafted bone.
Results: Fifteen patients had a mean period of graft consolidation of 19.7 weeks (range 13 to 32 weeks). Two patients had simultaneous graft and implant placement; 1 implant failed to integrate in this group. This represents a survival rate of 97.1% of implants in functional loading after a mean follow-up period of 153.6 weeks from occlusal loading (range 74 to 283 weeks).
Discussion and Conclusion: Mandibular block onlay grafts appear to be a predictable method for augmenting the width of the anterior maxilla prior to implant placement.

Bone is harvested from the mandibular symphysis. Note holes perforating the cortical plate.
Trimmed graft is fixed in place to augment the anterior maxillary alveolus.

Exposure of graft at 21 weeks. Resorption is assessed by noting the position of the fixture screws and the new cortical plate.
Placement of implants in augmented ridge.
Radiograph taken to check abutment connection just prior to occlusal loading.
Follow-up radiograph at 236 weeks after occlusal loading.
Key words: alveolar bone, bone grafting, endosseous dental implants, esthetics.

Caroline McCarthy, BDS, MMedSci
Raj R. Patel, BDS, FDS, MSc
Philip F. Wragg, BDS, FDS
Ian M. Brook, BDS, MDS, FDS, PhD
(*) Extraido de la revista "The International Journal of ORAL & MAXILLOFACIAL IMPLANTS" - 2003;18:238-241
   
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Wide-Diameter Implant Placement and Internal Sinus Membrane Elevation in the Immediate Postextraction Phase: Clinical and Radiographic Observations in 12 Consecutive Molar Sites (*)

Purpose: To evaluate whether the combination of 5 surgical techniques in implant dentistry could be performed simultaneously in a predictable manner as effectively as each technique separately.
Materials and Methods: Immediately postextraction, 12 wide-diameter (WD) implants were placed in maxillary first and second molar sites. The residual vertical bone height ranged between 6 and 9 mm (average 7.8 mm). An internal sinus elevation, via the osteotomy site, was carried out in 10 sites using and osteotome tool. Implants were then self-tapped into the osteotomy site followed by insertion of a customize healing screw. Consequently, horizontal gaps between the bony walls and the implant neck were filled by either bovine bone mineral or tricalcium phosphate particles. Full soft tissue closure around the healing cap screw was achieved by coronal positioning of the buccal flap.
Results: Soft tissue healing around the 12 implants was immaculate. In 10 sites, internal osteotome sinus membrane elevation resulted in a height gain of between 2.5 and 6 mm (average 4.3 mm). Radiographically, bone-to-implant contact was evident. All implants were integrated and the prosthetic phase was completed after 6 months.
Discussion and Conclusion: The combination of 1-stage technique and immediate placement of WD implants, along with internal sinus floor elevation and no soft tissue reflection at the time of implantation, is an achievable task and can be performed predictably. Time, cost and morbidity are reduce, and the prosthetic solution is also eased for the benefit of the patient.

Preoperative radiograph of the maxillary right molar before extraction.
The osteotome bur drills through the socket site, guided by the surgical template.
The periapical x-ray film and its base are connected to the surgical template by an acrylic resin.
The 8-mm mark on the osteotome cutting bur shows the exact bone height between the crestal extraction site and the maxillary sinus floor.

Measurement of the osteotome sinus membrane elevation instrument before placement.

ß-TCP particles are inserted by a plugger to the apical portion of the prepared site, under the slightly elevated sinus membrane.

The WD implant is placed, followed by insertion of a healing screw. Remaining bony gaps, ie, buccal socket roots, are filled with mineral particles.
A coronally positioned buccal flap enables soft tissue closure around implant.

Periapical radiograph shows osseous healing around the WD implant under the slightly elevated sinus membrane.
Soft tissue healing is established by a masticatory mucosal collar around the 1-stage WD implant.
Periapical radiograph shows implant after 2 years in function.
Key words: dental implants, extraction site, immediate implantation, maxillary sinus, sinus augmentation, wide-diameter dental implants.

Zvi Artzi, DMD
Alex Parson, DMD
Carlos E. Nemcovsky, DMD
(*) Extraido de la revista "The International Journal of ORAL & MAXILLOFACIAL IMPLANTS" - 2003;18:242-249
   
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Localized Vertical Maxillary Ridge Augmentation Using Symphyseal Bone Cores: A Technique and Case Report (*)

Vertical augmentation of the alveolar ridge is intended to restore resorbed alveolar ridges. This procedure is important for the placement of dental implants in a favorable position and also to enhance restoration esthetics. This article presents an approach for vertical ridge augmentation in the anterior maxilla utilizing symphyseal bone cores. A patient presented with 2 localized bony defects of 7 mm on the right and 6 mm on the left were observed in relation to the cementoenamel junction of the adjacent teeth. Two bone cores ewre harvested from the mandibular symphysis using a trephine. These bone cores were trapped into 2 predilled osteotomy sites with corresponding diameters until stabilization was achieved. The 2 sites were grafted with demineralized freeze-dried bone allograft and a titanium-reinforced expanded polytetrafluoroethylene membrane. After 5 months, the membranes wereremoved and vertical ridge augmentation of 5 mm on the right and 4 mm on the left was observed. The width of the ridge was increased as well. Two implants were placed in favorable positions, restored after 6 months, and followed successfully for 1 year after loading. This technique represents a viable approach for augmentation of deficient alveolar ridges prior to the placement of dental implants.

The patient at the time of initial clinical examination.
Periapical radiograph of the maxillary right lateral incisor. Notice the severe bone loss.
Periapical radiograph of the maxillary left lateral incisor showing severe bone loss.
Exposure of the symphysis and harvesting of the coritcocancellous bone cores.

Preparation of the osteotomy utilizing a 4.3-mm twist drill.

The 2 bone cores were tapped into the prepared osteotomy site until stabilization was achieved.

Grafted sites immediately after membrane removal and implant placement. Notice the restored vertical dimensions of the alveolar ridge and the favorable position of the implants in relation to the CEJ of the adjacent teeth.
Definitive restoration 1 year after loading.

Periapical radiograph taken after 1 year of loading of the implant placed in the site of the extracted maxillary right lateral incisor.
Periapical radiograph taken after 1 year of loading of the implant placed in the site of the extracted maxillary left lateral incisor.
Key words: alveolar ridge augmentation, bone cores, dental implants, mandibular symphysis.

Eliaz Kaufman, DDS, MS
Peter D. Wang, DDS, MS
(*) Extraido de la revista "The International Journal of ORAL & MAXILLOFACIAL IMPLANTS" - 2003;18:293-298
   
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