International Journal of Periodontics & Restorative Dentistry, 06/1998

One of the goals of the sinus elevation procedure is the creation of vital bone to effect the osseointegration of dental implants placed in the posterior maxilla. With this goal in mind, in 1993 the Department of Implant Dentistry at New York University College of Dentistry began a long-term clinical, histologic, histomorphometric, and radiographic study of the sinus elevation procedure. The primary parameters included the effects of graft material selection, time allowed for graft maturation, and the effect of barrier membrane placement on the creation of vital bone in the sinus cavity. The effects of these and other parameters on implant survival rates were also to be evaluated. This paper reports the data collected on a subgroup of 113 sinus elevations that used anorganic bovine bone matrix (OsteoGraf/N) alone or in combination with autogenous bone and/or demineralized freeze-dried bone as a graft material. This is the second in a proposed ser ies of papers that will result from this ongoing research project. The results of this study indicate that: OsteoGraf/N appears to be an effective graft material with a 98.2% implant survival rate to date; vital bone formation increased with time; vital bone formation increased moderately when demineralized freeze-dried bone allograft was added, and increased substantially when intraoral autogenous bone was added or when an expanded polytetrafluoroethylene membrane was used; and the increased height achieved by the procedure was stable over a 3-year period. Because of the high overall implant survival rate, it was not possible to determine the relationship between vital bone formation or membrane usage and implant survival.

A new mucogingival surgical technique for root coverage is proposed. Two kinds of flaps were obtained from the tissue surrounding the recession: the first, a partial thickness-epithelial connective flap, was designed to cover the second flap, which was a connective double-papilla flap positioned directly on the root surface. This technique was used to treat 11 cases of gingival recession ranging from 3 to 5 mm. After a period of 12 months, the mean root coverage was 84% with an average recession reduction of 2.7 mm, and the keratinized gingiva obtained was adequate in width and in thickness. The advantages of the suggested surgical technique are: (1) a single-step procedure is used, (2) there is no need for a second donor site, and (3) the achievement of a good final esthetic result with uniformity in the color and morphology of the flap relative to the surrounding tissues.

The present case report provides histologic findings on four titanium plasma-sprayed screw implants after 12 years of incorporation and functional load in a 95-year-old patient. At the time of implant placement, the four implants were immediately connected with a bar and functionally loaded with a bar-supported overdenture. The histologic analysis demonstrated excellent osseointegration in either cortical or cancellous bone for all implants. The histomorphometric analysis showed direct bone-implant contact of approximately 70% to 80% at the interface. Close to the implant surface, signs of ongoing bone remodeling activities were present. The present histologic case report confirms the validity of the applied treatment concept - to immediately load titanium implants with a titanium plasma-sprayed surface in the anterior region of the mandible - if a minimum of four implants can be inserted and if the four implants are splinted with a bar.

Tetracycline-discolored teeth that are to be restored by porce lain laminate veneers present a clinical challenge. Successfully bleaching such teeth prior to veneering will perm it the clinician and technician to overcome the technical difficulties associated with masking dark teeth. This article describes a combined treatment modality in which the teeth are bleached after the preparation for porcelain laminate veneers.

This study evaluated two bioresorbable polylactic acid barriers (Epi-Guide and Guidor) to determine if design differences were of therapeutic significance in the treatment of Grade II furcation defects in humans. Forty patients with bilaterally matched, Grade II furcation defects in maxillary or mandibular first or second molars were treated in a multicenter study. Comprehensive initial periodontal therapy, follwed by defect debridement and root preparation, preceded randomized membrane placement. Data collected from all three investigative centers were pooled and analyzed using an analysis of variance appropriate for a counterbalancing design. Both barrier types produced measurable improvements of clinical probing values. Barrier exposure scores taken through the eighth week postoperative revealed that Epi-Guide was less likely to become exposed than Guidor. The findings of this study, which was conducted over a 12-month period, demonstrated that Epi-Guide and Guidor were comparable as measured by clinical probing determinations.

Root-filled teeth with fractured or discolored coronal aspects invariably need to be restored by crowns. The prepared abutment tooth is usually reinforced by a metallic post and core system. The grayish discooration of the root, and consequently of the gingiva, caused by the metal color may be an enormous esthetic disadvantage in the anterior teeth. In 1993 ceramic posts made of zirconia were introduced by the authors, allowing a new all-ceramic concept for nonvital abutment teeth. A new ceramic post and core system has now been developed with the idea of further improving esthetic appearance. In this sytem the core material is heat pressed directly onto the zirconia post. This article describes the material and the fabrication procedures (chairside and in the laboratory) of the system. Clinical results are presented. The retention of the core material is evaluated by in vitro tests.

Signs and symptoms of the breakdown of the various components of the stomatognathic system, in particular the TMJ structures, masticatory muscles, dental structures, and periodontium, can have a variety of causes. Occlusal interferences have been implicated as one contributing factor in these areas of breakdown. If this is indeed the case, then elimination of these interferences should improve these signs and symptoms. A retrospective study involving 30 practicing dentists who make up part of the visiting faculty of the Pankey Institute analyzed a variety of signs and symptoms both prior to equilibration and after equilibration to elucidate signs and symptom dynamics following treatment.

The replacement of lost teeth and tooth-bearing tissues with implant-supported prostheses often forced both dentist and technician to choose removable overdentures because they were the only treatment modality possible. By means of a clinical case, this article demonstrates a new approach in framework design that not only expands the limitat ions of conventional ceramometal implant prostheses, but also eliminates a great number of the hazards that cause implant failure with a new type of suprastructure. The technique enables both the clinican and the technician to apply all of the esthetic possibilities of tooth-supported metal ceramic crown and bridge techniques. This technique combines screw and cementation retention without changing the original treatment protocol. A new casting technique introduced by Sonntag and a new specially developed alloy was used. Essentially, the reconstructive body has been broken down into a screw-retained soft tissue/bone-replacing part using a one-piece casting technique, and a crown-replacing part to be provisionally cemented with a large variety of new possibilities.