International Journal of Periodontics & Restorative Dentistry, 05/2006

The primary objective of this proof-of-principle study was to evaluate the outcome of vertical ridge augmentation in a standardized dog model by combining purified recombinant plateletderived growth factor (rhPDGF-BB) and a block of deproteinized cancellous bovine bone. The secondary objective was to determine the value of a resorbable barrier membrane to improve the efficacy of the procedure. Six adult foxhounds were committed to bilateral surgical extraction of all four mandibular premolars. A vertical alveolar ridge defect was created at the time of the extractions. Three months later, the artificially created defects were grafted: Group A used a deproteinized bovine bone block in combination with a collagen barrier membrane, group B used a deproteinized bovine bone block infused with rhPDGF-BB only, and group C included a deproteinized bovine bone block infused with rhPDGF-BB, plus a collagen resorbable barrier membrane. After 4 months, the animals were sacrificed. Histologic examination of group B revealed a large amount of newly formed bone, and a large amount of bone-to-implant contact was visible in the areas of bone regeneration extending over the top of the implant cover screw. The results of this preclinical canine study provide proof-of-principle that rhPDGF-BB, used in combination with a deproteinized bovine block without placement of a barrier membrane, has the potential to regenerate significant amounts of new bone in severe mandibular ridge defects. In addition, the results seem to point to the importance of the periosteum as a source of osteoprogenitor cells in growth factor-mediated regenerative procedures.

This patient presented with generalized severe chronic periodontitis. Conventional periodontal therapy would have left her compromised esthetically and anatomically, with growing interdental "black triangles." This prompted the authors to try to reconstruct the maxillary alveolar bone that had been lost in the previous three decades because of untreated periodontitis. To maintain the level and quality of the gingival margin, open flap surgery was performed in the maxilla soon after scaling and root planing. To gain access to the roots and bone surfaces, a flap was raised by intrasulcular incisions and the modified and simplified papilla preservation technique. After debridement, the root surfaces were conditioned and enamel matrix proteins were applied. Bovine bone mineral was placed in the infrabony defects and supracrestally (buccally, lingually, and interdentally) to help regenerate the lost alveolar bone. In addition, the defects around the maxillary anterior teeth were covered with a membrane. To prevent shrinkage of the gingiva, suspensory sutures were placed on the right central incisor and both left incisors so that the anterior flap would be positioned approximately 3 mm coronally. After surgery, the patient was advised to apply 1% chlorhexidine gel twice a day and to avoid brushing the surgical site for 4 weeks. Professional maintenance care was administered twice a week for 2 months and the patient was instructed to maintain a liquid diet for 4 weeks. The treatment outcome was evaluated clinically and radiographically at regular intervals for 5 years postsurgically. Periodontal conditions were stable and fulfilled the patient's desire to eliminate the pockets without compromising esthetics, particularly in the maxillary anterior.

Excessive gingival display can be managed by a variety of treatment modalities, depending on the specific diagnosis. This case report demonstrates the successful management of excessive gingival display with a lip-repositioning procedure. This is accomplished by removing a strip of mucosa from the maxillary buccal vestibule, then suturing the lip mucosa to the mucogingival line. This results in a narrower vestibule and restricted muscle pull, thereby reducing gingival display during smiling. This article reviews the basic technique for lip repositioning and discusses the indications and contraindications for this novel procedure in dentistry.

A fixed prosthesis, supported by implants, was fabricated prior to surgery and cemented with passive fit immediately after placement of 14 implants in the mandible. The prosthesis was constructed before implant surgery on a plaster cast that precisely reproduced the patient's hard and soft tissues. The cast was built using a method that allowed the transfer of hard and soft tissue anatomy from computerized tomograms. A rigid surgical stent, cast in gold, was used to place the implants into prosthetically ideal positions under three-dimensional control. The prosthesis was placed immediately after implant placement, using an occlusion-driven method, which avoided the need for occlusal adjustments to the prosthesis.

The zygomaticomaxillary region offers a large amount of cortical bone that can be obtained simply and safely using the precise and selective cutting properties of a piezosurgical device. A block from this area fits nicely into anterior or premolar maxillary recipient sites and is thus the ideal choice, as no secondary surgical field is needed. As in conventional sinus bone graft procedures, the complication rate is minimal and after a 5-month healing period, the augmented region can be used for stable and esthetic oral implant placement.

The aim of this investigation was to evaluate the clinical success of immediately loaded implants versus implants loaded in a delayed fashion in the posterior mandible. Three implants were placed distal to the canines bilaterally in the edentulous distal mandibular ridges of 12 patients. One side was randomly selected for placement of three implants (delayed loading; control sites) with a progressive thread design for submerged healing, and after 3 months the implants were exposed and loaded with provisional splinted crowns, which were replaced 6 weeks later by the definitive restorations. Three additional implants (immediately loaded; test sites), of the same size were placed in the contralateral side of the mandible. The test implants had abutments placed and were loaded immediately using the same protocol as the control implants. After a mean loading period of 25.3 months, the patients showed normal mean clinical values without significant differences (P 0.05) for test and control implants, respectively, as follows: Plaque Index: 0.4 versus 0.8; Sulcus Bleeding Index: 0.5 versus 0.3; probing pocket depth: 1.9 mm versus 2.1 mm; width of keratinized mucosa: 2.5 mm versus 3.3 mm; Periotest value: -3.7 versus -3.2. Twenty-nine of the examined sites showed no bone loss. After 2 years of loading in the posterior mandible, test and control implants had the same prognosis.

This study was designed to examine the sequential progress of healing, at two different time intervals, following delayed sinus augmentation using bovine hydroxyapatite (BHA) as the sole grafting material. Fourteen pairs of bone biopsies were taken from 10 patients after 6 and 12 months of healing, respectively. The biopsy specimens were examined histologically and histomorphometrically. The bone that was formed following sinus augmentation with BHA increased and matured over time up to 12 months after grafting; meanwhile, no overt signs of resorption of BHA were visible within the study period.

Impacted teeth present many problems for the orthodontist. They can compromise tooth movement, esthetics, and functional outcomes. The second most commonly impacted tooth, after the maxillary third molar, is the maxillary canine, with an incidence from 1% to 2.5%. Maxillary canines can be impacted facially or palatally and are more common in female patients than in male patients. Therefore, the purpose of this paper is to address the incidence and etiology associated with impacted maxillary canines, the clinical and radiographic evaluation of the situation, and the techniques for managing this problem. Papers related to this topic were identified and reviewed thoroughly. A decision tree involving the various techniques employed to expose impacted canines is presented, together with methods used to identify the location of impacted canines. The impacted canine can be properly managed with proper diagnosis and technique.

Previous publications have reviewed the concepts of implant diagnostics and computerized tomographic imaging used together to create an atmosphere of collaborative accountability. The use of SimPlant software in combination with stereolithographic medical modeling facilitates the fabrication of surgical drilling guides, which assist in precise placement of dental implants. In this article, the use of gradient density scanning appliances will be discussed. This type of scanning appliance allows tooth- or mucosa-supported surgical drilling guides to be fabricated and used for implant placement without bone exposure. The use of the SAFE System will be introduced, along with its application in simplifying the immediate-loading prosthesis concept, which can often bypass the need for traditional dental impressions.

Pathologic tooth migration related to periodontal disease is a common chief complaint of periodontal patients. This paper describes the treatment of a case of severe periodontal disease and disfiguring pathologic migration of maxillary central incisors, which required a multidisciplinary approach. After conventional periodontal treatment was performed, the anterior diastema was closed using a combination of orthodontic therapy and restorative treatment. A 6-month follow-up examination of this case revealed resolution of the anterior pathologic migration, with gains in clinical attachment levels and a successful esthetic and functional final result.