摘要:

The aim of the present study was to examine the microbiota on the internal surface of the components of 28 Brånemark implants® in 10 partially edentulous patients who had been treated with 1 fixed partial prostheses each. The prostheses had been in function for 1 to 8 years. The fixed prostheses were checked for mobility and removed. The abutment screws were loosened and classified as stable, easily removed or loose. Then, bacterial samples were obtained from the various internal surfaces of the implant system. Estimation and identification of the most predominant species was performed on the blood agar plates. Identification was based on Gram reaction, oxygen sensitivity and biochemical tests. Internal surfaces of different components of the Brånemark implants®, after varying periods of function in the oral cavity, consistently harboured a heterogeneous and primarily anaerobic microbiota. The individual samples showed a great variation. No relation could be seen between type and length of abutment, abutment stability, bone loss and type and number of microorganisms found in the samples. The flora consisted mainly of facultative and anaerobic streptococci, Gram‐positive anaerobic rods such as Propionibacterium, Eubacterium and Actinomyces species and Gram‐negative anaerobic rods including Fusobacterium, Prevotella and Porphyomonas species. There are reasons to suggest that this presence of bacteria is the result of (i) a contamination of the fixture and abutment components during the 1st and/or 2nd stage of implant installation and/or (ii) a transmission of microorganisms from the oral environment during function subsequent to bridge insta

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070201.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

Titanium implants were coated with hydroxyapatite by using a method of ion beam dynamic mixing. Coated and noncoated plates of titanium were placed in a growth medium with fibroblast cells. Implant screws, coated and noncoated, were inserted in rabbit bones and the animals were euthanized after 7, 27 and 122 days, respectively. The results from the cell culture test showed no visible difference between the specimens. Histologic examination of implant specimens indicated more new bone activity against coated screws at 27 days, and that was more pronounced at 127 days. Although the amount of new bone formation was not significantly different, certain signs of favourable new bone formation could be seen in contact with coated implants compared to the noncoated controls.

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070202.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

It has previously been reported that porous‐coated root form endosseous dental implants, became well integrated when used in the traditional 2‐stage surgical approach. In this study, the placement of the implant in a 1‐stage (non‐submerged)technique was to be explored. Implants were placed in the mandibles of dogs, and 2 designs were used differing only in that one (experimental) had a 3mm transgingival extension, permitting it to be exposed lo the oral cavity from the outset. 12 (3 per animal) non‐submerged implants were placed on I side of 4 beagle dogs and 12 control (submerged) implants were placed contralaterally. All implants were allowed to heal for 6 weeks, after which histological preparations were made. 2 of 12 non‐submerged implants were lost due to post‐operative complications: otherwise, all implants healed uneventfully. Histomorphometric analysis revealed bone‐implant contact, as assessed by absolute bone contact (ABC) and contact length fraction (CLF). to be greater for the submerged design, suggesting that bone healing may be delayed with the non‐submerged approach. As well. at this early stage of healing, for both implant designs, ABC and CLF were significantly greater on proximal than on buccal an

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070203.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

In order to achieve esthetically more satisfying results, it has been proposed to place ITI implants with their border between the rough and smooth surfaces below the level of the alveolar crest, thereby obtaining a submucosally located implant shoulder following healing. The aim of the present experimental study was to clinically and radiographically evaluate the tissue response to the placement of one‐stage transmucosal implants with the border between the rough and the smooth surfaces sunk by 1mm into a subcrestal location. 11 patients underwent comprehensive dental care including the placement of 2 implants of the ITI Dental Implant SystemTM in the same quadrant (test and control). Randomly assigned control implants were placed according to the manufacturer's instructions, i.e. the border between the rough titanium plasma‐sprayed and the smooth polished surfaces precisely at the alveolar crest. At the test implants the apical border of the polished surface was placed −1mm below the alveolar crest. Probing bone levels were assessed at implant placement (baseline), 4 and 12 months later. Modified plaque and modified gingival indices were recorded at 1, 2, 3,4 and 12 months. Clinical probing depth and “attachment” levels were measured at 4 and 12 months. All parameters were assessed at 6 sites around each implant. The mean for each implant was calculated and used for analysis. The Wilcoxon matched pairs signed rank test and the Student r‐test were applied to detect differences over time and between the test and control implants. At baseline, a mean difference in probing bone level of −0.86mm (SD 0.43 mm,p<0.05) was found between test and control implants with the test implants being placed more deeply. Both test and control implants lost a significant amount of clinical bone height during the first 4 months (test 1.16mm,p<0.05: control 0.58 mm.p<0.05). However, only the test implants significantly lost clinical bone height from 4–12 months (test 1.04 mm,p<0.05; control 0.45mm,p=0.08). Overall, the test implants lost 2.26mm and the control implants 1.02mm of bone height during the first year of service. On the average, the test implants demonstrated a bone level 0.38mm lower than the controls at 12 months. Except for the modified gingival index at 4 months (mean difference 0.21, SD 0.19,p<0.05), no clinical parameters yielded significant differences between test and control implants at any time. It is concluded that in addition to the crestal bone resorption occurring at 1 implants placed under standard conditions, the bone adjacent to the polished surface of 1 more deeply placed ITI implants is also lost over time. Form a biological point of view, the placement of the border between the rough and the smooth surfaces into a subcrestal location should not

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070204.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

In the present study, the influence of initial instability on the healing of titanium implants was studied in 9 lop‐eared rabbits. Titanium implants (Brånemark System®) were inserted in the tibiae, a location with cortical bone only, in such a way that they were either stable (control), rotation‐mobile, or totally mobile. Implants were also inserted in the distal femoral condyles, representing an implantation bed with mainly cancellous bone, so they either showed no initial mobility (control) or were rotation‐mobile. After 12 weeks of healing, the implants were retrieved, together with surrounding bone, fixed, dehydrated, and embedded in plastic resin. About 10 μm thick ground sections were prepared for light microscopic morphometry. The mineralized bone to titanium contact, and the amount of bone occupying the threads, were calculated, whereafter the outcome of the different locations were compared. All retrieved implants were clinically stable at the end of the experiment. For the tibia sites, a statistically significant less bone to titanium contact, and a less amount of bone in the threads, were found for the totally mobile implants, as compared to the corresponding initially stable controls. Moreover, a statistically significant higher amount of bone was found in the threads of the rotation‐mobile implants inserted in the femoral condyle as compared to their initially stable controls. The study indicated that initial rotation‐mobility. independent if it occurs in cortical or trabecular bone, does not necessarily lead to an inferior integration of unloaded implants. However, initial total implant mobility within the cortical layer results in a statistically significant less amount of lb one around the implants, as compared to sta

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070205.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

In the present study, the influence of initial instability on the healing of titanium implants was studied in 9 lop‐eared rabbits. Titanium implants (Brånemark System®) were inserted in the tibiae, a location with cortical bone only. in such a way that they were either stable (control), rotation‐mobile, or totally mobile. Implants were also inserted in the distal femoral condyles, representing an implantation bed with mainly cancellous bone, so they either showed no initial mobility (control) or were rotation‐mobile. After 12 weeks of healing, the implants were retrieved, together with surrounding bone, fixed, dehydrated, and embedded in plastic resin. About 10 μm thick ground sections were prepared for light microscopic morphometry. The mineralized bone to titanium contact, and the amount of bone occupying the threads, were calculated, whereafter the outcome of the different locations were compared. All retrieved implants were clinically stable at the end of the experiment. For the tibia sites, a statistically significant less bone to titanium contact, and a less amount of bone in the threads, were found for the totally mobile implants, as compared tothe corresponding initially stable controls. Moreover, a statistically significant higher amount of bone was found in the threads of the rotation‐mobile implants inserted in the femoral condyle as compared to their initially stable controls. The study indicated that initial rotation‐mobility, independent if it occurs in cortical or trabecular bone, does not necessarily lead to an inferior integration of unloaded implants. However, initial total implant mobility within the cortical layer results in a statistically significant less amount of lb one around the implants, as compared to sta

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070206.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

The aim of this prospective study was to characterize an implant patient population exhibiting clinical signs of peri‐implantitis and to determine subsequently the incidence of progressive attachment loss. The predictive values of diagnostic parameters were evaluated. 25 patients with 54 endosseous implants that had been loaded for 41±15 months were included in the study. Clinical parameters included the assessment of plaque, bleeding on probing, probing depth, attachment levels, and Periotest® values. Probing measurements were performed in duplicate by means of a controlled force electronic probe (Periprobem). Peri‐implant crevicular fluid samples were collected and assayed for neutral proteolytic enzyme (NPE) activity (Periocheck®). Analysis of duplicate baseline probing data revealed a high degree of reproducibility (mean difference: 0.1±0.3mm). A minimum threshold of 1.0mm (>3×S.D.) loss of probing attachment was chosen to classify a site as positive for breakdown. Alternatively, the tolerance method was employed to identify sites with progressive attachment loss. After 6 months, irrespective of the analytical method, 6 percent of all sites (in 19% of the implants) and 28% of the patients had experienced further per attachment loss. There were significant differences (p<0.05) in mean plaque (73% vs. 45%) and NPE (36% vs. 12%) scores between patients with progressive peri‐implantitis and those with stable peri‐implant conditions. Both bleeding on probing and the NPE‐test were characterized by high negative predictive values, and thus negative scores can serve as indicators for stable peri‐implant conditions. For monitoring peri‐implant health during recall visits, attachment level recordings with a controlled force electronic probe in conjunction with enzymatic diagnostic tests of the host response

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070207.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

The breakdown of bone around oral implants following excessive occlusal load or plaque accumulation was evaluated in monkeys. 5 screw type implants of pure titanium (Astra) were inserted in the mandible of 4 monkeys (Macaca Fascicularis). 2 implants were placed in each of the lateral segments and 1 in the frontal area. Each monkey was provided with 2 cemented splints covering the premolars and molars in the right and left side of the maxilla, respectively. 6 months after insertion of the fixtures, a fixed partial prosthesis was mounted on the 2 implants in one of the lateral segments. The prosthesis was in supra‐occlusal contact with the antagonizing splint. Each prosthesis was replaced during the course of the experiment. The renewed prosthesis caused a lateral displacement of the mandible during occlusion. and therefore resulted in a lateral rather than axial excessive occlusal load. Implants retaining the prosthesis were brushed 1 × a week and subgingival cleaning was performed 1 × a month. The remaining implants were never cleaned and. additionally, a cotton cord was placed passively around each of these to promote plaque accumulation. 5 out of 8 implants with excessive occlusal load lost osseointegration (mobility and peri‐implant radiolucency). The loss of osseointegration was observed 4.5 months to 15.5 months after the occlusal overload was commenced. None of the implants with plaque accumulation lost osseointegration, although an average loss of I .8 mm in the radiographic bone level was assessed after 18 m

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070208.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

Maximal occlusal force and oral tactile sensibility were recorded in 21 edentulous patients wearing maxillary complete dentures and mandibular fixed prostheses supported 1 by Brånemark implants. Bite force was measured with a miniature force transducer between antagonistic molars and premolars, and the passive tactile sensibility of the fixtures was recorded in the horizontal and vertical directions with spring balances. The active tactile sensibility was tested using steel foils 100 to 10 . The range of maximal occlusal force recorded was from 35 to 330N with highest values observed on the second premolars (mean 143N). Significantly lower forces were found on molars and first premolars (p<0.01). The detection threshold of minimal pressure was about 330g in the horizontal, and 388g in the vertical direction. This difference was not statistically significant. The average number of incorrect assessments when testing steel foils was 16.6 errors, out of 100 recordings. Similar results when using these 3 test modalities had been found on overdentures supported by two mandibular implants and occluding with maxillary complete dentures. The results of this study suggest that mandibular implants supporting fixed prostheses are not likely to improve oral tactile sensibility and maximal occlusal force in the presence of maxillary complete dentures

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070209.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY

摘要:

In this retrospective study of Brånemark™ system oral implants, 75 consecutive patients were treated with 84 implants for single‐tooth replacement from 1988 to 1993. Two implants were lost and not replaced: the first one before the abutment connection, the latter during the first year in function. The cumulative failure rate reached 2.4%during the 5‐year period. Seventy‐one percent of the implants were located in the incisor/canine region of both jaws. Twenty‐six per cent of the implants were inserted in special presurgical or surgical conditions. The mean annual bone loss as scored on radiograph, was 0.8mm during the first year and 0.1mm the following years. Different implant designs were used, a more pronounced bone loss was observed for the conical implant. The present data shows that the cumulative failure rate for single Brånemark™ implants and the radiographic bone loss is similar to that found around implants used for the treatment of complete and parti

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1996.070210.x

出版商:Munksgaard International Publishers    

年代:1996

数据来源: WILEY