Bone regeneration in the edentulous ridge expansion technique: histologic and ultrastructural study of 20 clinical cases.

The edentulous ridge expansion (ERE) technique is a partial-thickness flap procedure for implant surgery that was developed in 1986. The ERE technique permits the use of osseointegrated implants at sites whose minimal orofacial dimensions are insufficient for traditional implant surgery. The present work is a histologic and ultrastructural study of hard tissue repair modalities at edentulous sites that were treated with the ERE technique in 20 humans. Biopsies were obtained from the tissue regenerating within the surgically created bone gap between the mobile buccal and nonmobile lingual or palatal bone-periosteum plates ("bone flaps") on days 40, 90, 120, 150, and 480 (day 0 = day of implant insertion). The results suggest that osteoblasts differentiate from preexisting mesenchymal cells located on the original fissure walls, with consequent deposition of new bone in the surgically created intrabony defect.

Localized management of sinus floor with simultaneous implant placement: a clinical report.

Localized management of sinus floor (LMSF) achieves implant placement and sinus lifting simultaneously. LMSF is a further application of the principles of the edentulous ridge expansion (ERE) technique. It comprises the dissection of a partial-thickness flap, the buccal expansion of the residual alveolar bone, and the fracture and elevation of the sinus floor with simultaneous implant placement. Three hundred three patients were treated with 499 implants placed using the LMSF between April 1988 and December 1993. The selected patients, who showed no signs of sinus pathology, exhibited insufficient vertical alveolar bone dimensions for the placement of dental implants with the traditional technique. The minimal residual alveolar bone height was between 5 and 7 mm. Based on the criteria established by Albrektsson and his coworkers in 1986, the success rate of the 499 implants placed with the LMSF was 97.5%.

Healing at implants with and without primary bone contact. An experimental study in dogs.

The aim of the present investigation in the dog was to study: (i) if it was possible by the use of EREt to predictably expand the compromised alveolar ridge; (ii) if proper osseointegration also occurred at sites where the implant following installation was devoid of direct bone contact. 5 beagle dogs, about 1-year old, were included in the study. During a preparatory period, the mandibular premolars were extracted and the ridge in the edentulous regions markedly reduced. After 3 months of healing, ridge expansion surgery was performed. A partial thickness flap was raised on the buccal and lingual surfaces for the soft tissue preparation. The buccal part of the ridge was mobilised and the bone plate with its periosteum displaced in the buccal direction. In each quadrant, 2 fixture sites were prepared in the mandibular bone apical of the displaced bone plate. 2 unthreaded titanium plasma sprayed fixtures were installed in such a way that the coronal border of the fixture was flush with the level of the lingual and buccal bone plate. The "internal" distance between the mobile buccal and the non-mobile lingual bone plates was identical to the diameter of the fixtures, i.e., 3.3 mm, while the distance between the mesial and distal borders of the 2 implants and the mesial or distal bone was > 5 mm. In each quadrant, 1 additional fixture was installed in the non- reduced mesial part of the alveolar ridge (control site). 3 months after fixture installation, abutment connection was performed. Following abutment connection, a plaque control program was initiated and maintained for 4 months, at which time, the dogs were re-examined and biopsies obtained for histological examination. It was observed that bone regeneration and osseointegration may occur to titanium fixtures placed in surgically-created bone defects. The amount of bone that was in intimate contact with the fixture surface was similar in test and control sites. In addition, the periimplant mucosa at test and control implants had similar dimensions and composition in terms of junctional epithelium and connective tissue.

The edentulous ridge expansion technique: a five-year study.

This study presents the clinical results of a surgical technique that expands a narrow ridge when its orofacial width precludes the placement of dental implants. In 170 people, 329 implants were placed in sites needing ridge enlargement using the endentulous ridge expansion procedure. This technique involves a partial-thickness flap, crestal and vertical intraosseous incisions into the ridge, and buccal displacement of the buccal cortical plate, including a portion of the underiying spongiosa. Implants were placed in the expanded ridge and allowed to heal for 4 to 5 months. When indicated, the implants were exposed during a second-stage surgery to allow visualization of the implant site. Occlusal loading was applied during the following 3 to 5 months by provisional prostheses. The final phase was the placement of the permanent prostheses. The results yielded a success rate of 98.8%.

[Use of the stereo-microscope in endodontic surgery]. / Uso dello stereo-microscopio in endodonzia chirurgica.

The authors present several significant photographs of the apical anatomy of a tooth made using a stereo-microscope in the course of surgery. The authors generally use the stereo-microscope from the time of preparation of the apex to the retrograde filling. One of the changes which the authors have brought to traditional surgical procedures, the use of endodontic cement to improve the amalgam seal is illustrated. It consists of a modification which they introduced into their practice more than six years ago and even though it may be a simple clinical technique to use, it assured a significant long-term improvement in the cases treated.