摘要:

In 5 monkeys a total of 30 transmucosal endosseous dental implants were inserted in edentulous areas of the mandible with presence or absence of keratinized mucosa. After a healing period of 3 months with optimal plaque control, all implants were exposed to plaque accumulation for periods up to 9 months. To secure abundant plaque accumulation on half the number of the implants. cotton wool ligatures were placed around the implants at the entrance to the peri‐implant sulcus. Attachment loss was measured clinically and histometrically, and tissue recession was measured clinically. Ligated implants without keratinized mucosa demonstrated significantly more recession and slightly more attachment loss than the other implants. The results of this study suggest that the absence of keratinized mucosa around dental endosseous implants increases the susceptibility of the peri‐implant region to plaque‐induced tissue destru

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060301.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

The purpose of this study was to compare clinical, radiographic and histological differences around titanium oral implants loaded with either acrylic‐veneered metal or ceramo‐metal fixed prostheses. Five beagle dogs were used in this investigation. At the beginning of the study, all mandibular premolars and first molars were extracted. After 3 months of healing, 2 Brånemark implants were installed on each side of the mandibles. Three months later, abutments were inserted on each implant and a daily oral hygiene regime was initiated. One month after abutment connection, the implants on one side of the mandible were restored with an acrylic‐veneered metal fixed prosthesis, whereas, on the other side a ceramo‐metal fixed prosthesis was inserted. The prostheses were constructed in occlusion with the maxillary first molars. The following clinical parameters were measured around each implant at this time (i.e., baseline), and thereafter, at monthly intervals up to 5 months: Plaque Index; Gingival Index; implant mobility (using the Periotest®); probing depth and clinical attachment level (using the Florida Probe®). In addition, standardized radiographs were taken at baseline and 5 months after insertion of the prostheses and evaluated by subtraction radiography. Another Brånemark fixture was installed on each side of the mandibles 3 months before the end of the study. These implants remained unloaded and submerged for the entire study period. Five months after prosthesis insertion, the animals were killed, and implants with their supporting peri‐implant tissues were processed for histological evaluation. Analyses of the clinical, radiographic and histometric parameters revealed no significant differences between the acrylic‐veneered and ceramometal loaded implants. All clinical and radiographic parameters remained stable over time. Histological comparison of the alveolar bone height levels around both loaded groups with those from the unloaded, submerged implants revealed that a similar and slight loss of bone height (approximately 0.6 mm) occurred on the loaded groups following abutment connection. It was concluded that both acrylic‐veneered metal and ceramo‐metal suprastructures appear to be suitable for the restoration of endosseous oral implants. Additional long‐term studies in humans, however, are needed evaluating both types of implant‐supported prostheses, in a variety of clinical conditions. before final restorative r

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060302.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

The principle of guided tissue regeneration was applied in an attempt to generate bone to cover a subperiosteal implant. Titanium frame works, casted on individual impressions of the anterior surface of the tibia of 4 Copenhagen White rabbits, were stabilized to the tibia by microscrews, and half of them were covered by an expanded polytetrafluoroethylene augmentation membrane. The observation period was 12 weeks. Guided bone regeneration partly covering the implants was seen at all experimental sides; on the control sides the implants were mainly embedded in fibrous tissue. Studies are in progress with the aim of reducing marked marrow space formation observed in all the regenerated areas.

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060303.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

The placement of oral implants into jaw bone has a high predictability provided an adequate bone volume surrounding the implant is present to ensure primary stability and resistance to functional loading forces after completion of osseointegration. In the distal area of the maxilla, an adequate bone volume is often lacking because of the proximity of the sinus cavities. The aim of this study was to evaluate histologically the simultaneous placement of endosseous implants into the sinus cavity and the surgical elevation of the sinus floor including filling the cavity with different grafting materials. In 9 sinus areas of 5 beagle dogs, 9 titanium implants (ITI® Dental Implant System( were placed, and the void space of the sinus cavity was filled simultaneously with either demineralized freeze‐dried human cortical bone (Musculoskeletal Transplant Foundation), resorbable hydroxyapatite (Osteogen®) or natural cancelleous bovine bone mineral (Bio‐Oss®). To study bone formation, fluorochrome markers (tetracycline HCI and calcein green) were used at 2 and 8 weeks. Clinically, all implants healed uneventfully, and 5 months after implant placement the dogs were killed for histologic evaluation. All implants exhibited osseointegration within the pre‐existing cortical bone of the sinus floor. The implants surrounded by freeze‐dried bone xenografts yielded no formation of new bone, whereas the sites with hydroxyapatite or natural bovine bone mineral demonstrated newly formed bone with direct contact at the implant surface. The average extent of bone to implant contact was 25%(SD= 10.6%) and 27%(SD=8.8%), respectively in relation to the length of the originally denuded implant surface. In addition, the bone markers revealed a rapid bone formation and remodeling, especially around natural bovine bone mineral particles. This study yields new bone formation with direct contact to the implants surfaces in the sinus cavity into which suitable grafting materials were placed simultaneously. Resorbable hydroxyapatite (Osteogena) and natural cancellous bovine bone mineral (Bio‐Oss®) were osteoconductive and hence were suitable for bone formation around endoss

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060304.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

A method using cutting resistance measurements during low‐speed threading for identification of various bone densities has been evaluated with regard to its precision and potential. Pig ribs were used as test samples. Differing hand pressure, minor deviation (5") from a vertical tapping direction and individual threading did not reveal any significant differences in cutting resistance values. After implants were inserted into the threaded canals, the total bone as well as trabecular and compact bone areas surrounding the implants were calculated via a computer program and using microradiographs of the bone test samples. The outcome of the cutting resistance measurements was compared with that of the microradiographic technique, and good agreement was observed between the two procedures in the ability to identify bone density. Therefore, cutting resistance measurements may in the future also be used to clinically identify bone qualities in ja

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060305.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

Distortions of 15 routine implant‐supported prostheses were measured in relation to the master casts after completion by means of a 3‐dimensional (3‐D) photogrammetric technique. All prostheses were designed as one‐piece gold‐alloy castings with resin teeth. Five of the prostheses were placed in the edentulous maxilla, and the remaining were placed in the lower jaw. Distortion of the cylinders was mostly observed in the horizontal plane (x‐and y‐axis) while the vertical aspect seemed to be more stable. The mean 3‐D center point distortion was 42 (SD 15) and 74 (SD 38)μm for the upper and lower jaws, respectively. The measurements revealed a range of3‐D center point distortion from 16 to 80 and 15 to 165 μm for the different jaws, respectively. The corresponding 3‐D mean angular distortion of the cylinders was 51 (SD 35)μm in lower and 70 (SD 75)μm in the upper jaws. A correlation was found between 3‐D center point distortion and the width as well as the curvature of the implant arch, indicating more displacement the wider and the more curved the arch was. The 3‐D center point distortion was also significantly higher in the upper jaws which could possibly be explained by the curvature of the implant arch and higher numbers of implants in the upper jaws. Further problems with the fit of upper jaw castings could be related to more alloy in the 1 castings and

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060306.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

A total of 190 single crystal sapphire implants, 85 short (4S9S) and 105 long (4S9L), were monitored with panoramic and intraoral radiographs for 3 years. The implants were used as abutments for overdentures in edentulous mandibles in 51 patients. Within the first year, 2 patients lost one implant each due to pain and lack of osseointegration. Neither was replaced and the superstructures remained stable. At baseline registration, i.e., immediately after the prosthetic installation, the bone height relative to the length of the implant was calculated. The mean bone implant score (BIS) was 63.55±1.34%(mean±SE). BIS decreased during the first year 62.18±1.51%. At the 2‐ and 3‐year recordings, the mean BIS were 61.81±1.58% and 61.73±1.63%, respectively. There were no statistically significant differences in BIS changes over the 3‐year period or between men and women. The decrease in mean BIS was greater for implants in the premolar region than in the incisor region and for short implants than for lon

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060307.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY

摘要:

This investigation evaluated guided bone regeneration with a polytetrafluoroethylene barrier membrane at exposed parts of Bråemark dental implants with and without concomitant use of decalcified freeze‐dried bone allograft. Density of the regenerated tissue was also determined using a No. 23 probe at a pressure of 25g and was graded from 1 to 5. The higher index was associated with a higher resistance of newly formed tissue to the pressure of the probe. In 19 patients, 23 defects were treated by barrier membrane alone and 11 defects by bone allograft with barrier membrane. The width and the depth of the defects were determined at the time of the implant placement and at the second‐stage implant surgery. When success was defined as 0 mm of residual defect, the mean success rate was 68% for the membrane group and 90% for the membrane group with bone allograft, with no statistically significant difference between the two treatment groups. The two groups did not demonstrate a significant difference in median density index. There was a significant positive relationship between time of membrane coverage and density index. A density index of 4 was only recorded after 7 months of membrane coverage. The present findings suggest beneficial clinical effect with the use of membrane alone and freeze‐dried bone allograft with membrane for guided bone regeneration. This study proposed the use of a novel density index of clinical evaluation of regenerated

ISSN:0905-7161    

DOI:10.1034/j.1600-0501.1995.060308.x

出版商:Munksgaard International Publishers    

年代:1995

数据来源: WILEY