摘要:

The purpose of this study was to characterize and compare by scanning electron microscopy (SEM) the maturation of supragingival microbial plaque on enamel and smooth titanium and that of subgingival plaque on cementum, plasma‐sprayed titanium and hydroxyapatite surfaces. Specimens (6.5 x 2 x 1 mm) were obtained from titanium implants with smooth transmucosal collars and plasma‐sprayed endosseous posts of titanium or hydroxyapatite. Unerupted third molars were sectioned to similar dimensions that included equal lengths of enamel and root surface. Ten patients with post‐treatment pocket depths of>6 mm on 3 non‐adjacent teeth were selected and each had 1 set of the 3 specimen types bonded by random assignment to the selected teeth. Specimens were positioned so that enamel and/or smooth titanium surfaces were supra‐gingival and cementum and titanium or hydroxyapatite plasma‐sprayed surfaces were subgingival. Patients were instructed to stop oral hygiene, after which 2 specimen sets were removed at 1, 3, 5, 7 and 10 days. Two specimens of each type were examined by SEM at each time interval for supra‐ and subgingival plaque. The sequence of appearance of various microbial morphotypes in supra‐ and subgingival plaque was similar regardless of surface. In both supra‐ and subgingival plaque, depending on time interval, cocci, rods of various lengths, filamentous organisms, fusiforms, spirochetes and corn‐cob formations were observed. Mineralized plaque was noted on most subgingival specimens by day 10. These observations indicate that surface of natural teeth, smooth titanium and plasma‐sprayed titanium and hydroxyapatite support the maturation of microbial plaque with the successive inclusion of a v

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040201.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

In this investigation, the tissue reactions towards titanium implants inserted in growing jaws of pigs were studied by means of histology. At the age of 12 weeks, 5 test pigs each received 4 Brånemark System* titanium implants (fixtures). The fixtures were inserted immediately after extraction of the mesial root of the second deciduous premolar (P2) and the deciduous canine (C) on one side of the mandible and the mesial root of the first deciduous premolar (PI) on the other side. The fourth implant was placed after extraction of the deciduous lateral incisor (L) on one side in the upper jaw. Furthermore, 1 pig in which no extractions or fixture installations were performed served as a control. All pigs were followed for 165 days with clinical, radiographic and biometric examinations, the results of which have been previously presented. In this study, 10‐μm‐thick ground sections were produced for histology after the jaws had been fixed by immersion in formalin and further processed and embedded in plastic resin. Six of the fixtures originally inserted were lost during the experimental period, and the remaining implants were found to be involved with mineralized bone to varying degrees. Regarding the fixture‐to‐teeth relationship, it was found that, in the premolar region of the lower jaw, the teeth were positioned superior to and buccally angulated in relation to the fixtures. In the upper jaw, the implants were positioned below the adjacent teeth but centrally in the alveolar process. Tooth germs adjacent to the fixture had a displaced eruption path, buccally or lingually to the fixture. If the bud developed in close contact with the fixture, a changed morphology of the germ could be

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040202.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

An experiment was carried out to determine whether endosseous titanium implants (Brånemarks®) retain their clinical stability throughout a 26‐week period of continuously applied force (2 N) and what kind of marginal peri‐implant bone changes occur in the process. For this purpose 6 premolars (P3: mandible/maxilla and P4: mandible) were extracted from each of 2 foxhounds, and 12 implants (6 per dog) were positioned in the edentulous maxillary and mandibular areas after the alveolar healing period. Following a 25‐week implant healing period, 8 fixtures (P3 areas) were used as anchoring elements for distalization of the 2nd premolars over a period of 26 weeks: 4 implants served as a control group (P4areas of the mandible). There were no clinical or histological signs of implant dislocation after the load application period. In the presence of mild peri‐implant gingivitis, no increase was found in the incidence of marginal bone resorption adjacent to the loaded implants compared with the non‐loaded implants. In the absence of marginal resorption, subperiosteal bone apposition was detected especially around the test implants in the mandible. This suggests that endosseous titanium implants are suitable as anchoring units for longer‐term orthodontic tooth movements. The applied force may moreover induce marginal bone appositions adjacent I to

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040203.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

The aim of this study was to evaluate the marginal tissue response adjacent to implant supported overdentures. Twenty edentulous patients had 2 Astra Dental Implants® placed in the canine region of the lower jaw. New overdentures were retained by individual ball attachments in 11 patients and by a bar attachment in 9 patients. Periodontal registrations were recorded 0 months, 6 months, 12 months and 24 months after the overdentures were inserted. One of the 40 fixtures was lost at the stage of abutment connection. No fixtures were lost during the 2‐ to 4‐year observation period and no fixtures showed any periodontal signs of failure. At the 2‐year examination, no pocket depths adjacent to the implants exceeded 4 mm and no bone loss exceeded 3 mm. The mean annual bone loss was less than 0.2 mm during the first 2 years. The preliminary results from this limited study were promising and showed that two osseointegrated Astra Dental Implants® could successfully retain an overdenture in the lower jaw. However, long‐term observation is needed for a definate evaluation of this treatmen

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040204.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

Clinical and radiographic examination was used to select patients with a suspected need of guided tissue regeneration GTR. Fifteen patients with 20 fixtures were included in the study. Nine (45%) of the fixtures were completely covered with bone at fixture surgery and no GTR was required in these cases. On the remaining 11 fixtures, one or more sites were exposed and thus an expanded polytetrafluoroethylene membrane was used. The regenerative results were assessed using 2 methods, a) calculation of exposed threads in the mouth and on projected colour slides, b) photometric evaluation of exposed area. In total, the membrane group showed a bone gain of 81% when threads were calculated. Almost complete agreement in percentage of bone gain was observed between buccal (80.7%) and lingual (82.6%) sites. Photometric evaluation for the buccal sites showed a bone gain of 74%. Complete bone regeneration (100%) was achieved when healing was free from complications and also under an exposed membrane when infection was absent. The results indicate that the membrane technique is highly successful for treatment of exposed implants when healing is free from complications. It also shows that clinical and radiographic examination is not precise enough to differentiate between those patients planned for routine fixture surgery and those with a supplementary need for GTR. Thus access to GTR technique is important when treatment is 1 planned for borderline cases.

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040205.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

Strain gauges were used to record invivaand invitrofunctional deformations in a fixed prosthetic appliance supported and retained by osseointegrated titanium implants. Four linear gauges were attached to each of totally 5 implant abutment cylinders and gauge signals were transferred into a computer via a digital converter. A computer program (ASYST) was used for collection, calibration and analysis of data obtained. Based on the results of a series of explorativein vitrotests,in vivaexperiments were performed at maximum biting as well as during chewing on certain normally available food items. The results show fundamental differences betweenin vitroand invivotesting conditions. Unexpectedly high bending of the implants was recorded in many of thein vivaloading situations.

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040206.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY

摘要:

Complete restoration of an osseous defect around a TiAl6V4(IMZ) implant is accomplished by the combined use of an implant placed in the alveolus of a fractured lower bicuspid and the principles of guided tissue regeneration. Gengiflex (Gengiflex ‐ BioFill ‐ Productos Biotecnologices, Curitiba, PR, Brazil), a new membrane, was used to cover the implant and porous hydroxyapatite was used as grafting material. The filling of the osseous defect that also covered the implant was verified clinically at re‐entry 6 months later. Histological analysis of the mineralized tissue collected during exposure of the implant confirmed bone form

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1993.040207.x

出版商:Munksgaard International Publishers    

年代:1993

数据来源: WILEY