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| 2. |
- Friberg, Bertil, 1950, et al.
(författare)
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Inferior alveolar nerve transposition in combination with Brånemark implant treatment.
- 1992
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Ingår i: The International journal of periodontics & restorative dentistry. - 0198-7569. ; 12:6, s. 440-9
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Tidskriftsartikel (refereegranskat)abstract
- The surgical protocol for inferior alveolar nerve transposition together with the Brånemark implant treatment is described. The short-term follow-up results of the first ten procedures are presented and show an initial 2- to 3-week duration of anesthesia. In all regions treated, signs of paresthesia/hypoesthesia have been registered for 1 to 7 months. After 6 months, seven of the regions recovered completely with regard to nerve sensation.
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| 3. |
- Hoeber, Jan, 1986-, et al.
(författare)
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A Combinatorial Approach to Induce Sensory Axon Regeneration into the Dorsal Root Avulsed Spinal Cord
- 2017
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Ingår i: Stem Cells and Development. - : Mary Ann Liebert Inc. - 1547-3287 .- 1557-8534. ; 26:14, s. 1065-1077
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Tidskriftsartikel (refereegranskat)abstract
- Spinal root injuries result in newly formed glial scar formation, which prevents regeneration of sensory axons causing permanent sensory loss. Previous studies showed that delivery of trophic factors or implantation of human neural progenitor cells supports sensory axon regeneration and partly restores sensory functions. In this study, we elucidate mechanisms underlying stem cell-mediated ingrowth of sensory axons after dorsal root avulsion (DRA). We show that human spinal cord neural stem/progenitor cells (hscNSPC), and also, mesoporous silica particles loaded with growth factor mimetics (MesoMIM), supported sensory axon regeneration. However, when hscNSPC and MesoMIM were combined, sensory axon regeneration failed. Morphological and tracing analysis showed that sensory axons grow through the newly established glial scar along "bridges" formed by migrating stem cells. Coimplantation of MesoMIM prevented stem cell migration, "bridges" were not formed, and sensory axons failed to enter the spinal cord. MesoMIM applied alone supported sensory axons ingrowth, but without affecting glial scar formation. In vitro, the presence of MesoMIM significantly impaired migration of hscNSPC without affecting their level of differentiation. Our data show that (1) the ability of stem cells to migrate into the spinal cord and organize cellular "bridges" in the newly formed interface is crucial for successful sensory axon regeneration, (2) trophic factor mimetics delivered by mesoporous silica may be a convenient alternative way to induce sensory axon regeneration, and (3) a combinatorial approach of individually beneficial components is not necessarily additive, but can be counterproductive for axonal growth.
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| 4. |
- 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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| 5. |
- Ivanoff, Carl-Johan, et al.
(författare)
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Influence of initial implant mobility on the integration of titanium implants. An experimental study in rabbits.
- 1996
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Ingår i: Clinical oral implants research. - 0905-7161. ; 7:2, s. 120-7
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Tidskriftsartikel (refereegranskat)abstract
- 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 micron 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 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 bone around the implants, as compared to stable controls.
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| 6. |
- 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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| 7. |
- Ivanoff, Carl-Johan, et al.
(författare)
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Influence of soft tissue contamination on the integration of titanium implants. An experimental study in rabbits.
- 1996
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Ingår i: Clinical oral implants research. - 0905-7161. ; 7:2, s. 128-32
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, the influence of peroperative soft tissue contamination 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 one group was inserted the standard way (control), and another group was contaminated for 30 s in the adjacent soft tissues, prior to insertion. The implants were allowed to heal for 12 weeks and were then retrieved together with surrounding bone, fixed, dehydrated and embedded in plastic resin. About 10 micron 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 for each implant, and the results of the two groups were compared. All retrieved implants were clinically stable at the end of the experiment. Regarding bone-to-titanium contact and bone area within the threads, a statistically nonsignificant difference was observed between the 2 groups. This study indicated that peroperative soft tissue contamination of c.p. titanium implants does not prevent osseointegration from occurring, when studied in the rabbit tibia.
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| 8. |
- Ivanoff, Carl-Johan, et al.
(författare)
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Influence of variations in implant diameters: a 3- to 5-year retrospective clinical report.
- 1999
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Ingår i: The International journal of oral & maxillofacial implants. - 0882-2786. ; 14:2, s. 173-80
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Tidskriftsartikel (refereegranskat)abstract
- Sixty-seven patients ranging in age from 16 to 86 years were included in this 3- to 5-year retrospective report focusing on implant survival and marginal bone remodeling in relation to implant diameter. A total of 299 Brånemark implants (3.75-mm diameter: 141; 4.0-mm diameter: 61; 5.0-mm diameter: 97) were placed in 16 completely and 51 partially edentulous arches. Seven of the 141 implants in the 3.75-mm-diameter group failed (5%). The corresponding value for the 4.0-mm-wide implants was 2 of 61 (3%). The highest failure rate, 18% (17/97), was seen for the 5.0-mm-diameter implants. The least favorable cumulative survival rates were seen in mandibles after 5 years and involving 4.0-mm- and 5.0-mm-diameter implants (84.8% and 73.0%, respectively). The marginal bone loss was generally low over the 5-year period. When the data were evaluated by the Cox regression analysis, a relationship was found between implant failure and implant diameter (P < .05), with a higher failure rate for the 5.0-mm-diameter implant. However, no relationship could be seen between implant failure and jaw type, or bone quality and quantity (P > .05). Neither was any relationship seen between marginal bone loss and bone quality and quantity, implant diameter, or jaw type when tested by multiple linear regression analysis (P > .05). A learning curve, poor bone quality, and changed implant design were suggested as possible reasons for the less positive outcome seen for the 5.0-mm-diameter implant. The fact that this implant was often used as a rescue implant when the standard ones were not considered suitable or did not reach initial stability was another plausible explanation.
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| 9. |
- Ivanoff, Carl-Johan, et al.
(författare)
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Reintegration of mobilized titanium implants. An experimental study in rabbit tibia.
- 1997
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Ingår i: International journal of oral and maxillofacial surgery. - : Elsevier BV. - 0901-5027. ; 26:4, s. 310-5
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of re-establishing a rigid bone-implant fixation, i.e. osseointegration, after mechanical loosening of titanium implants, was evaluated in the rabbit tibia. Implants were inserted to engage either one (10 mm long, n = 24) or two (16 mm long, n = 24) cortical layers and were allowed to heal for six weeks. A re-entry was then made and 12 test implants in each group subjected to a reverse torque procedure until the integration failed. The remaining nonrotated 24 implants were left as controls. Thereafter all implants were allowed to heal for an additional period of six weeks. At the end of the 12 weeks, the degree of integration was assessed by measuring the removal torque for six test and six control implants in each group of implant lengths. Histomorphometric measurements were also performed on ground sections of the remaining test and control implants. A statistically significant higher removal torque was observed for the monocortical test implants than for the corresponding control implants. No differences were seen for the bicortical implants of either kind, however, no morphological differences could be revealed either, when comparing monocortical and bicortical test and control implants. These results indicate that osseointegrated implants that have been mobilized due to a traumatic disruption of the bone-implant interface, may reintegrate if allowed to heal for an additional period of time.
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