The International Journal of Oral & Maxillofacial Implants, 01/1991

The safety and efficacy of placing endosseous implants into the anterior mandible at the time of dental extractions with appropriate radical alveolectomies (immediate implants) is reported. The results were compared to a control group of patients. The success of the immediate group was 92.7%; that of the control group was 98.1%. The difference in success rates was not significant at the P .05 level. Keywords: extractions, immediate implants, radical alveolectomy

The philosophy of retaining natural teeth as long as possible for the preservation of alveolar bone has been a fundamental concept of dental treatment. With the introduction of predictable osseointegrated implant supported prostheses, placement of an implant immediately after dental extraction can be considered. This paper discusses the technique of implant placement immediately following dental extraction. Clinical experience including 61 patients with follow-up of 1 to 6 years is reported. Keywords: alveoloplasty, endosseous implant, immediate placement

One hundred seven dental implants were inserted to support single tooth restorations in 92 patients participating in a prospective multicenter investigation. Only three implants (2.8%) were lost after 1 year of clinical function. Most of the remaining restorations were esthetically successful by using modified components. The gingival condition was healthy around the single crowns and coincided well with the clinical situation around the permanent teeth. The most obvious problem experienced during the first year was related to loose abutment screws. Twenty-six percent of the screws retaining crowns were retightened during the observation period, but the frequency of loose screws had a tendency to decrease as the study progressed. Keywords: Brånemark System®, multicenter investigation, single implant restorations

An endosseous implant that should allow osseointegration as well as fixation by connective tissue has been developed. A special surface structure consisting of titanium wire loops on a titanium implant was produced by diffusion bonding. The mechanical properties of this implant are investigated. Keywords: endosseous implants, titanium implants, surface structure

Glycosaminoglycans (GAG) in gingival crevicular fluid (GCF) samples were determined by cellulose acetate electrophoresis and densitometric scanning. Two GAG bands, hyaluronic acid and chondroitin-4-sulphate (C4S), were detected in GCF from implants, similar to the profile from teeth. High GCF volumes and GAG contents, notably C4S, may reflect postoperative alveolar bone responses, particularly resorption, at different stages of healing and function of successful implants. They may also indicate adverse tissue changes in failing implants. A comparison of crowned implants and matched teeth suggests that the periodontal ligament contributes to the GCF GAG profile. This may be a useful laboratory method of monitoring implants to detect adverse tissue responses at an early stage. Keywords: dental implants, gingival crevicular fluid, glycosaminoglycans, implant monitoring

This study investigated the risk of corrosion of titanium abutments by the accidental or unauthorized use of preventive fluorides in the mouth. Polished test pieces of commercially pure ASTM grade 1 titanium were immersed in topically used fluorides (toothpaste, gel, and varnish). They were brushed in vitro with toothpaste and gel, corresponding to the time and effect of brushing with toothpaste twice a day for 6 years and with gel once a week for 12 years. Results indicate that an aminofluoride toothpaste with low ionizable fluoride content (0.125%) used in brushing natural teeth does not cause deterioration of the titanium abutments in the same mouth if the titanium is grade 1 purity. Carefully controlled use of fluoride gel (F 1.25%) and varnish (F 2.25%) is likewise not dangerous. The mechanical abrasion caused by toothbrush bristles appears to be the main deteriorating factor for the titanium surface. Keywords: commercially pure titanium, corrosion, fluorides

Implant mobility as an indicator of failing close bone apposition is generally known. Whereas a clearly visible mobility can always be correlated with an interposition of soft tissue, the range from a clinically firm implant to just tangible implant mobility represents the actual problem zone. Thirty consecutive patients who had mandibles restored with osseointegrated implants ad modum Bränemark were tested with the Periotest device for damping characteristics of the implants and the peri-implant tissues as a whole. The mean Periotest value (PTV) was-1.74. The characteristics of the mandible, the peri-implant tissue, and the abutment length are the determining factors for the PTV. Fixture length, dolder bar, and length of time in function had no significant influence on the PTV. Keywords: bone apposition, implant mobility, Periotest

Bone changes following the placement of apatite implants are examined using standardized radiographs and digital image processing. This paper validates the methodology and presents obvious bone changes following the placement of apatite implants. Keywords: apatite implants, digital image processing, radiography

For preimplantologic evaluation and diagnosis, there are various mechanical methods for measuring the thickness of the soft tissue and thus indirectly measuring the osseous bed of the implant. This study evaluated the use of real-time sonography for analyzing the soft-tissue thickness of the entire edentulous maxilla in an anatomic examination of human cadaver specimens. The data obtained were compared with findings from the usual needle measurement method. The ultrasound measurement method produced realistic data in all measurement points of all sectional planes selected. Keywords: preimplantologic diagnosis, soft-tissue bed, ultrasound

A survey of experience treating patients with extraoral implants for facial prosthesis retention in 13 United States centers and in Sweden has been completed. Patients who have not received radiation for elimination of malignant disease can be treated with reasonably good expectations for long-term success. Reported success rates indicate that patients who have received radiation should be selected carefully and treated with caution, since overall success rates in this category are disappointingly low. Keywords: extraoral implants, facial prostheses, multicenter study, radiation therapy

Maxillary prosthetic restorations on osseointegrated implants are often problematic because of implant location, orientation, and need for lip support. A new design for a hybrid maxillary prosthesis that will provide good esthetics and phonetics, as well as ensure optimum conditions for oral hygiene and patient comfort, is proposed. The design includes separate support, lateral stabilization, and retention. Support is derived from elevated areas at the midline and on the extensions of a bar screwed to dental implants ad modum Brånemark. Lateral stabilization is obtained by a removable framework closely fitting the bar. Four precision attachments provide adjustable retention without influencing support. Technical aspects of the procedure are described. Keywords: endosseous implant, overlay denture, precision attachment, prosthesis design