The International Journal of Oral & Maxillofacial Implants, 02/1991

The purpose of this investigation was to evaluate the technique of guided tissue regeneration on a clinical and histologic level for generating new bone adjacent to osseointegrated implants. Cylindrical, press-fitted, titanium plasma flame-coated implants were modified by a disk screwed onto the implant. After implant insertion, the disk-implant assembly was covered by an expanded polytetrafluoroethylene membrane. In one group, the space underneath the membrane was filled with hydroxylapatite granules; in the control group, no membrane was used. Clinical and histologic results demonstrate that the principle of guided tissue regeneration is applicable to osteogenesis in humans. Keywords: bone regeneration, guided tissue regeneration, osteogenesis, Teflon membrane

Activation of complement leads to the generation of C3a and C5a inflammatory peptides. C5a is a potent chemotactic factor, stimulating the secretion of proteolytic enzymes by neutrophils and osteoclast activating factor/Interleukin-1 by monocytes. In vitro generation of C3a and C5a was measured by radioimmunoassay techniques. The results showed significant complement activation by all implants tested when compared to the control serum incubation. It is concluded that all of the implants studied activated the complement system and are not physiologically inert. Complement activation, therefor, may contribute either positively to healing or negatively to a poor outcome in osseoadaptation initially or over time. Keywords: complement, implant, Interleukin-lß, osseoadaptation

This study comprised 4,641 Brånemark dental implants, which were retrospectively followed from stage 1 surgery to completion of the prosthetic restorations. The implants were placed during a 3-year period (1986 to 1988) in 943 jaws, representing 889 patients with complete and partial edentulism. The jaw and sex distribution revealed a predominance of mandibles (564/943) and females (534/943). The mean age of the patients was 57.5 years (range 13 to 88 years) at implant placement. Only 69 (1.5%) fixtures failed to integrate, and most losses were seen in completely edentulous maxillae (46/69), in which the jaw bone exhibited soft quality and severe resorption. A preponderance of failures could also be seen among the shortest fixtures (7 mm). A majority of the mobile implants were recorded at the abutment connection (stage 2) operation (48/69). Keywords: Brånemark implants, failures

With the increased use of dental implant systems, an increase in the number of implants removed from patients has also been observed. This investigation attempted to elucidate some underlying causal determinants of implant failure employing light microscopic analyses. Valuable data can be obtained from implants retrieved from patients. Implant success is predicated on proper patient selection and treatment planning, careful surgical procedures, careful prosthodontic management, and continued oral hygiene maintenance. Keywords: diagnosis, inflammatory response, light microscopy, retrieved dental implants, support system

A fixed partial denture is preferred as a prosthetic restoration supported by tissue-integrated oral implants. However, there are occasions, especially in restoring an edentulous maxilla, when a fixed partial denture does not satisfy a patient's requirements for esthetics, good phonetics, proper oral hygiene, and oral comfort. A removable hybrid prosthesis attached to a bar that is conventionally fixed to tissue-integrated implants ad modum Brånemark was therefore designed to satisfy such needs and to meet requirements for splinting of the implants. Following the placement of prostheses, patients were asked to give their opinion on the comfort, phonetics, and esthetics of the prosthesis by marking a visual analog scale. The results indicate a successful initial outcome of the treatment. Keywords: dental prosthesis design, endosseous dental implants, overlay denture, precision attachment denture, prosthodontics, visual analog scale

Digital subtraction radiography is proposed as a potential diagnostic tool for implant research and patient monitoring. Examples of the application of this technique are given observing peri-implant density changes during the early healing phase and during ligature-induced peri-implantitis in an animal model. Additional cases document the loss of peri-implant bone density associated with an infection and increase in density caused by remodeling after functional loading of an implant with a single crown. Digital subtraction radiography might be one of the most sensitive noninvasive methods for assessing subtle density changes in peri-implant tissues, providing additional diagnostic information on implant tissue integration and maintenance. Keywords: diagnosis, digital subtraction radiography, implants, standardized radiographs

Mechanical in vitro tests of the Brånemark implant disclose that the screw joint which attaches the prosthetic gold cylinder and the transmucosal abutment to the fixture forms a flexible system. This inherent flexibility seems to match well the vertical mobility of a supporting tooth connected to the implant. Calculations of vertical load distribution based on measured flexibility data demonstrate that the forces are shared almost equally between tooth and implant even without taking the flexibility of the surrounding bone or the prosthesis into account. The therapy of a single Brånemark implant connected to a natural tooth should be considered without any additional element of a flexible nature. Mechanical tests and theoretical considerations, however, indicate that the transverse mobility of the connected tooth should be limited and that the attachment of the prosthesis to the tooth should be of a rigid design to avoid gold-screw loosening. Keywords: Brånemark implant, connection to natural tooth, implant flexibility, intramobile element, screw joint, tooth mobility

This study was designed to determine the effect of time on the biomechanical integration of cylindrical dental implants in the mandible and maxilla. A total of 136 IMZ dental implants was placed bilaterally in the endentulous maxillae and mandibles of 17 goats. Pullout tests were used to assess biomechanical integration at intervals from 2 to 24 weeks. This study indicated that there is a time-dependent, progressive increase in pullout force to 24 weeks. The forces were consistently higher for the mandible than the maxilla. Moreover, there was no correlation between the intraoperative stability of the implant and the postoperative pullout force. Keywords: biomechanics, dental implants, goats, mandible, maxilla

New esthetic two-piece titanium abutment cylinders have recently been introduced for the Brånemark implant system. The conical design allows for the fabrication of fixed partial dentures with improved esthetics compared to the conventional abutment design. The improved feature provides for the ability to begin the restoration closer to the implant while still maintaining a titanium/soft-tissue interface. Two designs, one short and one long, are currently being produced. The components, techniques, and clinical advantages of the short two-piece esthetic abutment are reviewed. Keywords: abutment cylinder, conical abutment, gold cylinder, titanium collar, titanium / soft tissue interface

ITI implants, which are transmucosal from the time of placement, require relatively few components or instruments for the procedures involved in prosthetic restoration. The salient features of postsurgical care and management are discussed with respect to treatment of edentulous patients using overdentures retained by retentive anchors and bar attachments. Keywords: ITI implants, overdentures, prosthetic management

A technique for using a surgical guide construction with a self-retaining feature, which has proven to be a significant improvement for stage 1 surgical procedures, is described. This design is more convenient to use than previously described occlusal extension splints. It maintains the concepts for ideal fixture placement that have proven so valuable in creating both a functionally and esthetically uncompromised prosthesis supported by implants. Keywords: implant placement, self-retaining surgical guide

Whether the result of technical errors or anatomic aberrations, malalignment of osseointegrated implants can create significant difficulty for the restorative dentist who fabricates the final tissue-integrated prosthesis. As a result, the planned prosthesis may defy completion or the implants may have to be left buried. This clinical report illustrates a solution to fabricating a fixed/detachable tissue-integrated prosthesis on malaligned posterior mandibular implants. Keywords: implants, malalignment, partial edentulism

Suture granulomas mimic neoplasms in clinical appearance and may increase in frequency as dental implant therapy increases. This case report illustrates the clinical and histologic features of this sometimes perplexing postoperative complication. Keywords: foreign-body reaction, infection, postoperative complication, suture granuloma