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- Lundgren, Stefan, et al.
(författare)
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Simultaneous or delayed placement of titanium implants in free autogenous iliac bone grafts. Histological analysis of the bone graft-titanium interface in 10 consecutive patients.
- 1999
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Ingår i: International journal of oral and maxillofacial surgery. - : Wiley. - 0901-5027 .- 1399-0020. ; 28:1, s. 31-7
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to histologically analyse the bone graft-titanium implant interface after six and twelve months of healing for a simultaneous approach and after six months for a delayed approach. For this purpose, screw-shaped c.p. titanium microimplants, 2 mm in diameter and 5 mm long, were placed and retrieved at different time intervals in ten consecutive patients with severely resorbed maxillae and treated with iliac cortico-cancellous bone grafts and titanium implants in a two-stage procedure. The histomorphometrical analyses of ground sections of the specimens showed a higher degree of bone-implant contact and more bone filling the implant threads in the delayed approach microimplants. This was probably due to the partly revascularized grafted bone in the delayed approach being able to respond to the surgical trauma, resulting in interfacial bone formation. It is concluded that the results from the present study favour the use of a delayed approach when using free autogenous bone grafts and titanium implants for reconstruction of the severely atrophied maxilla.
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- Lundgren, Stefan, et al.
(författare)
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Bone grafting to the maxillary sinuses, nasal floor and anterior maxilla in the atrophic edentulous maxilla. A two-stage technique.
- 1997
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - 0901-5027 .- 1399-0020. ; 26:6, s. 428-434
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the results from 20 consecutive patients treated with an autogenous bone graft from the iliac crest. In ten patients the graft was placed in the maxillary sinuses and the floor of the nose (inlay group). Ten patients, in addition to the inlay graft, had a corticocancellous bone block secured with mini-screws to the anterior maxillary ridge (inlay/onlay group). Endosteal implants (Brånemark) were placed six months after surgery. A total of 136 implants were placed, of which eight failed to integrate during the six-month healing period. A further 15 implants were lost during the follow-up period. For the inlay group the average follow-up period was 22 months and for the inlay/onlay group 19 months. Donor site morbidity was significantly less when iliac bone was harvested with a trephine (inlay group) than in patients treated with our routine procedure for bone harvesting (inlay/onlay group). Surgical technique, donor site morbidity, implant survival and patient acceptance are presented.
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- Nyström, Elisabeth, et al.
(författare)
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Autogenous onlay bone grafts fixed with screw implants for the treatment of severely resorbed maxillae. Radiographic evaluation of preoperative bone dimensions, postoperative bone loss, and changes in soft-tissue profile.
- 1996
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - 0901-5027 .- 1399-0020. ; 25:5, s. 351-359
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Tidskriftsartikel (refereegranskat)abstract
- Thirty patients with severely resorbed edentulous maxillae underwent combined treatment of iliac bone onlay graft and titanium implants. The patients were followed for 3 years. They were radiographically examined before surgery to evaluate the bone volume at the intended implant sites. Only 13/156 implant sites were suitable for implant insertion. The bone level at the implant surfaces was evaluated after 6 months and 1, 2, and 3 years, respectively. There was a continuing decrease of the bone level throughout the follow-up period with a mean loss of 4.9 mm after 3 years and with no difference between sexes. Twenty-six implants were radiographically examined before removal, and only three of these implant sites showed radiographic signs of failure. The soft-tissue profile was analyzed cephalometrically by the subtraction technique. The upper lip generally moved inward and the apex of the nose and the columella downward and inward. The anterior facial height increased in most of the patients, resulting in a downward and inward change of the lower lip, the mentolabial sulcus, the soft-tissue pogonion, and the soft-tissue gnathion.
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4. |
- Nyström, Elisabeth, et al.
(författare)
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Combined use of bone grafts and implants in the severely resorbed maxilla. Postoperative evaluation by computed tomography.
- 1995
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - 0901-5027 .- 1399-0020. ; 24:1 Pt 1, s. 20-25
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Tidskriftsartikel (refereegranskat)abstract
- Combined horseshoe-shaped iliac bone grafts and Brånemark fixtures were used to rehabilitate patients with severely resorbed maxillae. Twenty patients were followed-up by computed tomography (CT) examination with axial slices to assess the fixture sites and to study the changes in height and width of the bone graft 3 weeks and 3, 6, 12, and 24 months postoperatively. The mean height of the bone graft at the 3-week postoperative examination was 8.2 mm; after 2 years the mean value had decreased to 6.2 mm. The height reduction occurred mainly between the 3-month and 1-year examinations. The mean width of the bone graft at the 3-week postoperative examination was 12.2 mm, and it decreased to 8.6 mm after 2 years. Most of the width reduction took place during postoperative months 1-3. From 1 year after the grafting procedure, the rate of reduction of both height and width was very low.
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5. |
- Nyström, Elisabeth, et al.
(författare)
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Interpositional bone grafting and Le Fort I osteotomy for reconstruction of the atrophic edentulous maxilla. A two-stage technique.
- 1997
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Ingår i: International Journal of Oral and Maxillofacial Surgery. - 0901-5027 .- 1399-0020. ; 26:6, s. 423-427
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Tidskriftsartikel (refereegranskat)abstract
- This study presents the results from ten consecutive patients who, because of insufficient bone volume for conventional implant placement in the maxilla, were treated with an interpositional bone graft and Le Fort I osteotomy. The endosteal implants were placed six months after the osteotomy. A total of 60 screw-shaped titanium implants (Brånemark) were placed, of which three failed to integrate during the six-month healing period. No further implants were lost during the follow-up period, ranging from 15 to 39 months after placement of the implants. All patients received fixed bridges and all have continued to function efficiently.
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9. |
- Ivanoff, Carl-Johan, et al.
(författare)
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Influence of implant diameters on the integration of screw implants. An experimental study in rabbits.
- 1997
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Ingår i: International journal of oral and maxillofacial surgery. - : Elsevier BV. - 0901-5027. ; 26:2, s. 141-8
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Tidskriftsartikel (refereegranskat)abstract
- The influence of diameter on the integration of titanium screw-shaped implants was studied in the rabbit tibia by means of removal torque measurements and histomorphometry. Implants 3.0, 3.75, 5.0, and 6.0 mm in diameter and 6.0 mm long were inserted through one cortical layer in the tibial metaphyses of nine rabbits and allowed to heal for 12 weeks. The implants were then unscrewed with a torque gauge, and the peak torque required to shear off the implants was recorded. The histologic analysis in undemineralized ground sections comprised (1) a gross description of the implant sites and assessments of (2) the total implant length in bone and (3) in the cortical passage, as well as (4) the thickness of the cortical bone adjacent to the implants. From the removal torque values obtained and morphometric measurements, a mean shear stress value was calculated for each implant type. The biomechanical tests showed a statistically significant increase of removal torque with increasing implant diameter. The resistance to shear seemed to be determined by the implant surface in supportive cortical bone, whereas the newly formed bone at the periosteal and endosteal surfaces did not seem to have any supportive properties after 12 weeks. It is suggested that wide diameter implants may be used clinically to increase implant stability.
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10. |
- Ivanoff, Carl-Johan, et al.
(författare)
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Influence of mono- and bicortical anchorage on the integration of titanium implants. A study in the rabbit tibia.
- 1996
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Ingår i: International journal of oral and maxillofacial surgery. - : Elsevier BV. - 0901-5027. ; 25:3, s. 229-35
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Tidskriftsartikel (refereegranskat)abstract
- The study aimed to evaluate the removal torque and bone tissue response to titanium implants supported by one or two cortical layers. A total of 72 screw titanium implants, either 10 or 16 mm in length and 3.75 mm in diameter, were inserted in right and left tibiae of 18 adult New Zealand rabbits. The implants engaged either one or two cortical layers, and the animals were allowed a healing period of 6 or 12 weeks. The degree of integration was assessed by measuring the removal torque with a torque gauge manometer. Histomorphometric calculations were also performed in 10-microns-thick ground sections. All implants were clinically stable at the end of the experiment. The removal torque was two times higher for the bicortical implants after 6 weeks, and three times higher after 12 weeks, than for the monocortical ones. The 16-mm implants also showed a statistically higher amount of bone contact and bone area after 6 and 12 weeks, respectively, than the short ones. The results support bicortical anchorage of implants also in the clinical situation.
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