International Journal of Periodontics & Restorative Dentistry, 03/2009

This preclinical study evaluated the efficacy of purified recombinant human platelet-derived growth factor (rhPDGF-BB), combined with a novel equine hydroxyapatite and collagen (eHAC) bone block, in providing vertical bone regeneration in critical-size defects simulating localized mandibular alveolar bone atrophy. In addition, the impact of barrier membrane placement in growth factor-mediated bone regeneration was also studied. Bilateral posterior mandibular defects simulating severe localized bony atrophy were created in 12 adult foxhounds following removal of all four mandibular premolars. Three months later, the defects were grafted as follows: group A: eHAC block alone; group B: eHAC block + collagen membrane; group C: eHAC block + rhPDGF-BB; group D: eHAC block + rhPDGF-BB + membrane. The animals were sacrificed after 5 months and the grafted areas were examined histologically, radiographically, and clinically. Groups A and B (controls) exhibited little to no vertical bone regeneration. Group C demonstrated significant vertical bone regeneration, with dense, well-vascularized bone, high bone-to-implant contact, and accelerated replacement of graft particles with newly formed bone. In group D, with the imposition of a barrier membrane, robust bone regeneration was less evident when compared to group C. As in the first study in this series, the importance of the periosteum as a source of osteoprogenitor cells in growth factor-mediated regenerative procedures is examined.

This case cohort study was designed to evaluate the healing response of a minimally invasive surgical technique (MIST) in combination with enamel matrix derivative (EMD) in isolated deep intrabony defects. Forty deep intrabony defects were surgically accessed with the MIST. This technique was designed to limit the flap extent and reflection to reduce surgical trauma and increase flap stability. EMD was applied on the dried root surfaces. Surgery was performed with the aid of an operating microscope and microsurgical instruments. The 1-year clinical attachment level gain was 4.9 ± 1.7 mm. Seventy percent of defects gained >= 4 mm. Clinical attachment level gain was significantly associated with the depth of the three-wall component of the defect, with the intraoperative bleeding tendency of the defect, and with its interaction with the baseline amount of bone loss. Defect morphology and bleeding tendency seem to influence clinical outcomes from the use of MIST in combination with EMD.

The purpose of this study was to perform a three-dimensional observation, via microvascular corrosion casts, of the microcirculation system during deposition of cementum after flap surgery and to investigate the permeable structure of the vascular endothelium. Two stages of wound healing after flap surgery were confirmed based on successive vascular changes. The transition between these stages occurred 3 weeks after surgery, at which time new blood vessels disappeared and an early stage of accumulation of new cementum was apparent. Hence, fibrous repair occurred during the first stage, and repair of hard tissue (ie, formation of cementum) occurred during the second stage. These findings suggest that metabolic activity in cementogenesis is low, based on the condition of the blood vessels, and therefore new cementum is not easily formed.

Newly developed ultrasonic diamond-coated tips (UDT) have been created for sulcus penetration and intracrevicular finish line preparation and polishing. One hundred forty-two freshly extracted premolars and molars were employed for a cutting efficiency test. Dentin surface roughness was analyzed with an optical profilometer and a scanning electron microscope. Within a reasonable cutting time, the UDTs possessed sufficient dentin-cutting capacity. The surface roughness of dentin prepared with the UDT can be improved by using a smaller grit size UDT or a smooth tip set at lower power, and the roughness approaches that of dentin prepared with a referenced red diamond bur. A clinical protocol of ultrasonic sulcus penetration with these developed UDTs is proposed.

The present paper reports on a patient who underwent vertical ridge augmentation using recombinant human platelet-derived growth factor-BB (rhPDGF-BB) in combination with a scaffold made of deproteinized bovine bone block. Forty-five days after the extraction of a mandibular central incisor, an NT (tapered profile) Osseotite implant was inserted into the extraction socket. A 9-mm vertical bone defect was present and treated with the use of a xenograft block infused with rhPDGF-BB. The soft tissues showed perfect healing after 2 weeks. After 6 months, reentry surgery was performed. At this time the clinical evaluation showed complete bone regeneration, with the presence of hard bonelike tissue all around the implant. Radiographic evaluation showed integration of the bovine xenograft with the residual basal bone, together with optimal bone-to-implant contact and a reorganization of the lamina dura on the interproximal sites of the adjacent teeth. The implant was then successfully restored with a metal-ceramic crown. This human report supports the use of rhPDGF-BB in combination with a bovine bone block for accomplishing challenging vertical ridge augmentation.

This study compared the dimensions of the peri-implant soft tissues around immediately and early loaded one-piece implants as well as conventionally loaded onepiece implants. Comparisons of the peri-implant soft tissue dimensions were made among four different loading periods. Forty-eight titanium sandblasted/acidetched implants were placed in four foxhounds. The implants were placed at four time periods in groups of three. The first group (A) had implants placed 3 months before the placement of restorations. Further groups of three implants each were placed at 21 days (group B), 10 days (group C), and 2 days (group D) before restoration. Three months after abutment connection, all dogs were sacrificed. Histometric analysis of the undecalcified histologic sections included dimensional measurements of the sulcus depth plus junctional epithelium, the connective tissue contact area, and recession measured from the interface to the gingival margin. No statistically significant differences were observed among the four groups. The data suggest that the dimensions of the peri-implant soft tissues around immediately and early loaded one-piece implants are similar to those around conventionally loaded one-piece implants and comparable to the dimensions of the biologic width around natural teeth.

This article examines a new prosthetic procedure for the immediate loading of implants with a fixed prosthesis in edentulous or potentially edentulous arches. In these situations, one of the main problems associated with immediate loading is the transfer of diagnostic information to the master cast. This technique takes advantage of an acrylic resin transfer plate that enables transfer of the study cast information to the master cast. Without any intrasurgical impression or any recording of the maxillomandibular relationship during or after surgery, construction of an adequate esthetic and functional fixed prosthesis is possible on the basis of diagnostic information acquired in the presurgical phase. The methodology is always applicable when there is an indication for immediate loading of implants. The rationale and guidelines for the successful use of this technique in edentulous or potentially edentulous arches are discussed and illustrated with a clinical case.

This work sought to investigate the clinical efficacy of esterified hyaluronic acid for treating deep periodontal defects. Nineteen defects, 18 infrabony and one mandibular molar furcation, were treated. Defects with probing pocket depths (PPDs) of at least 6 mm were consecutively included in the study. The PPD, gingival recession, and clinical attachment level (CAL) were evaluated at each defect before treatment and 1 year after surgery. A full-thickness flap was raised and the roots were accurately planed; hyaluronic acid in the form of fibers was then packed into the defect to completely fill the space. One year after treatment, the mean PPD was reduced by 5.8 mm (range, 0 to 10 mm), gingival recession had increased by 2.0 mm (range, 0 to 6 mm), and attachment gain was 3.8 mm (range, 0 to 7 mm).

Many articles have detailed local accidents and complications in dental implant treatment. Comparisons of the data they report are not always easy because different criteria have been followed in the various classifications and there is confusion between the terms accident and complication. The aim of this paper is to propose a classification that considers the timing of the events and makes a distinction between the two terms. Accidents are events that occur during surgery, and complications are any pathologic conditions that appear postoperatively. The proper diagnostic procedures and surgical techniques for their prevention and treatment are also described.

One of the main limitations of orthodontic treatment in partially edentulous patients is the lack of anchorage to obtain desirable tooth movement. Coordination between the orthodontist, periodontist, and restorative practitioner is essential when planning treatment for these patients. Implants can be used not only in the definitive prosthetic solution but can also be of great benefit as stable abutments during orthodontic therapy. For ideal results, it is essential to establish an orthodontically favorable position for an implant and, more importantly, the best position for an adequate restoration following orthodontic treatment. The aim of this article is to demonstrate the use of implants in orthodontic movement to provide easier and more predictable restorative treatment.