摘要:

New technology coupled with a better understanding of tissue biology has played a key role in restoring the somewhat tarnished image of implant dentistry. Thanks to carefully conducted longitudinal studies, it has now become clear that the replacement of missing teeth by artificial implants integrated into the living tissues of the jaws is a predictable procedure, as long as certain guidelines are followed in the manufacture of the implant, in its placement, in its eventual functional loading, and in its maintenance (Adell et al. 1981, Aibrektsson 1988, Albrektsson et al. 1988, Babbush et al. 1986, Kirsch&Mentag 1986, Smithloff 1986,Smithloff&Fritz 1987). Yet, functional success for a natural tooth is dependent on a number of anatomic, physiologic, and environmental considerations which differ in some important respects from those that insure the functional success of an implant. In this paper, we review theanatomic features of the natural dentition with emphasis on the periodontal tissues, and contrast these characteristics with those that exist 1 around well‐integrated endosseous implant

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1991.020101.x

出版商:Munksgaard International Publishers    

年代:1991

数据来源: WILEY

摘要:

Identity of film positioning and of X‐ray beam angulation is essential for valid comparisons of marginal bone height around osseointegrated implants. The purpose of the present study was to analyze the possibilities of estimating fixture angulation in relation to film plane from the threads of Brånemark fixtures. 10 observers compared 62 images of fixtures with angulations ranging from 0" to ± 15" with a set of reference radiographs. Out of 620 recordings, 29% were right, and 71% differed by ≥ 1". The observers distinguished with great accuracy between negative and positive angulations. 81% of the recordings differed by 2" or less. It is concluded that the threads of Brånemark fixtures are helpful in controlling the identity of serial radiographs of implants. The test circumstances were ideal compared to clinical cases, and it is possible that accuracy will be less in patient

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1991.020102.x

出版商:Munksgaard International Publishers    

年代:1991

数据来源: WILEY

摘要:

Screw‐shaped commercially pure (c.p.) niobium and c.p. titanium implants were inserted in rabbit bone. After a healing period of 3 months, a significantly higher removal torque was demonstrated to unscrew the niobium implants (average 32.9 Ncm) compared to the c.p. titanium implants (average 25.3 Ncm). In the histomorphometric part of the study, there were no significant differences in bone‐to‐metal contact between the 2 implant materials. An average of 41.1% bony contact was demonstrated for the niobium screws compared to an average of 37.2% for the c.p. titanium ones. Our removal torque findings could be related to the differences that we observed between the 2 implant surfaces as indicated by SEM. Since niobium implants showed a more irregular surface topography and niobium is a softer metal than c.p. titanium, this seems the most probable reason for the differences observed in removal torque between the 2 metals. Hypothetically, a more “positive biocom‐patibility” of the c.p. niobium in comparison to the c.p. titanium remains as another possible reason for the observed differences. However, against such a difference in biocompatibility between c.p. niobium and c.p. titanium, there is the very similar amount of bony contact registered 1 in the histomorphometr

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1991.020103.x

出版商:Munksgaard International Publishers    

年代:1991

数据来源: WILEY

摘要:

A qualitative and quantitative histological study of the initial healing response adjacent to 24 submerged and non‐submerged implants placed in the lower jaws of 6 monkeys is presented. The histomorphometric analysis showed no significant differences in mineralized bone‐implant contact length between submerged and non‐loaded non‐submerged titanium implants. The infrabony defects around some of the implants on the radiographs were significantly correlated to the histological measurements. Qualitatively, a greater number of gingival inflammation cells and a longer junctional epithelium were seen adjacent to non‐submerged implants without oral hygiene than were seen adjacent to non‐submerged implants with oral hygiene in the initial hea

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1991.020104.x

出版商:Munksgaard International Publishers    

年代:1991

数据来源: WILEY

摘要:

Different studies have shown that various substances may have an influence on early human dental plaque formation. The purpose of the present study was to compare on tooth substances and supporting prosthetic materials the amount of plaque deposition by SEM and the quantity of selected bacteria using anaerobic culturing techniques. 5 bridges, replacing a missing molar or premolar, were incorporated in 3 patients. In the midbuccal area of each pontic, a semi‐precision attachment was placed allowing the insertion of the following test facings: enamel, dentine, non γ2‐amalgam, alloys of 85% and 55% gold, silver‐palladium, chrome‐cobalt, chrome‐cobalttitanium, and ceramic. For each material, 2 facings were fabricated. After 4 and 24 hours in situ, bacteriological samples were taken and processed for further identification. After a 2nd period of 4 and 24 hours in situ, the same facings were carefully removed and prepared for SEM‐examination. All 4‐hour specimens exhibited various areas covered by plaque, the amount of which varied with the different supporting substances. The very smooth surfaces (e.g., gold) harbored sparse deposits, while the rougher (e.g., amalgam) were covered by more plaque. After 24 hours of plaque development, an increase in the number of micro‐organisms was noted for all the specimens. After 4 and 24 hours of plaque accumulation, no specific trends suggesting a preferential colonization on the different substances were observed. This study has shown that the amount of early deposits on different substances seems to be related to the degree of their surface roughness, while plaque formation was quali

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1991.020105.x

出版商:Munksgaard International Publishers    

年代:1991

数据来源: WILEY