| 1. |
- Sul, Young-Taeg, 1960, et al.
(författare)
-
Optimum surface properties of oxidized implants for reinforcement of osseointegration: surface chemistry, oxide thickness, porosity, roughness, and crystal structure
- 2005
-
Ingår i: International Journal of Oral & Maxillofacial Implants. - Chicago, Ill. : Quintessence Pub. Co.. - 0882-2786 .- 1942-4434. ; 20:3, s. 349-59
-
Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To investigate detailed surface characterization of oxidized implants in a newly invented electrolyte system and to determine optimal surface oxide properties to enhance the bone response in rabbits. MATERIALS AND METHODS: A total of 100 screw-type titanium implants were prepared and divided into 1 control group (machine-turned implants) and 4 test groups (magnesium ion-incorporated oxidized implants). Forty implants were used for surface analyses. A total of 60 implants, 12 implants from each group, were placed in the tibiae of 10 New Zealand white rabbits and measured with a removal torque test after a healing period of 6 weeks. RESULTS: For the test groups, the oxide thicknesses ranged from about 1,000 to 5,800 nm; for the control group, mean oxide thickness was about 17 nm. The surface morphology showed porous structures for test groups and nonporous barrier film for the control group. Pore diameter ranged from < or = 0.5 microm to < or = 3.0 microm. In regard to surface roughness, arithmetic average height deviation (Sa) values varied from 0.68 to 0.98 microm for test implants and 0.55 microm for control implants; developed surface ratio (Sdr) values ranged from 10.6% to 46% for the test groups and were about 10.6% for the control group. A mixture of anatase and rutile-type crystals were observed in the test groups; amorphous-type crystals were observed in the control group. After a healing period of 6 weeks, removal torque measurements in all 4 test groups demonstrated significantly greater implant integration as compared to machine-turned control implants (P < or = .033). DISCUSSION: Determinant oxide properties of oxidized implants are discussed in association with bone responses. Of all surface properties, RTVs were linearly increased as relative atomic concentrations of magnesium ion increase. CONCLUSIONS: Surface properties of the oxidized implants in the present study, especially surface chemistry, influenced bone responses. The surface chemistry of the optimal oxidized implant should be composed of approximately 9% magnesium at relative atomic concentration in titanium oxide matrix and have an oxide thickness of approximately 1,000 to 5,000 nm, a porosity of about 24%, and a surface roughness of about 0.8 microm in Sa and 27% to 46% in Sdr; its oxide crystal structure should be a mixture of anatase- and rutile-phase crystals.
|
|
| 2. |
- Suska, Felicia, 1974, et al.
(författare)
-
In vivo cytokine secretion and NF-kappaB activation around titanium and copper implants.
- 2005
-
Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 26:5, s. 519-27
-
Tidskriftsartikel (refereegranskat)abstract
- The early biological response at titanium (Ti), copper (Cu)-coated Ti and sham sites was evaluated in an in vivo rat model. Material surface chemical and topographical properties were characterized using Auger electron spectroscopy, energy dispersive X-ray spectroscopy and interferometry, respectively. The number of leukocytes, cell types and cell viability (release of lactate dehydrogenase) were determined in the implant-interface exudate. The contents of activated nuclear transcription factor NF-kappaB, interleukin-6 (IL-6) and interleukin-10 (IL-10) were determined by enzyme linked immunosorbent assay. An increase in the number of leukocytes, in particular, polymorphonuclear leukocytes, was observed between 12 and 48 h around Cu. A marked decrease of exudate cell viability was found around Cu after 48 h. The total amounts of activated NF-kappaB after 12 h was highest in Ti exudates whereas after 48 h the highest amount of NF-kappaB was detected around Cu. The levels of cytokine IL-6 were consistently high around Cu at both time periods. No differences in IL-10 contents were detected, irrespective of material/sham and time. The results show that materials with different toxicity grades (titanium with low and copper with high toxicity) exhibit early differences in the activation of NF-kappaB, extracellular expression and secretion of mediators, causing major differences in inflammatory cell accumulation and death in vivo.
|
|
| 3. |
- Thor, Andreas, et al.
(författare)
-
The role of whole blood in thrombin generation in contact with various titanium surfaces
- 2007
-
Ingår i: Biomaterials. - : Elsevier BV. - 0142-9612 .- 1878-5905. ; 28:6, s. 966-74
-
Tidskriftsartikel (refereegranskat)abstract
- Understanding of the thrombotic response (activation of the intrinsic coagulation system followed by platelet activation) from blood components upon contact with a titanium dental implant is important and not fully understood. The aims of this study were to evaluate: (1) the thrombogenic response of whole blood, platelet-rich plasma (PRP) and platelet-poor plasma (PPP) in contact with a highly thrombogenic surface as titanium, (2) the thrombogenic response of clinically used surfaces as hydroxyapatite (HA), machined titanium (mTi), TiO2 grit-blasted titanium (TiOB) and fluoride ion-modified grit-blasted titanium (TiOB-F). An in vitro slide chamber model, furnished with heparin, was used in which whole blood, PRP or PPP came in contact with slides of the test surfaces. After incubation (60 min rotation at 22 rpm in a 37 degrees C water bath), blood/plasma was mixed with EDTA or citrate, further centrifuged at +4 degrees C (2200 g at 10 min). Finally, plasma was collected pending analysis. Whole blood in contact with Ti alloy resulted in the binding of platelets to the material surface and in the generation of thrombin-antithrombin (TAT) complexes. With whole blood TAT levels increased 1000-fold compared with PRP and PPP, in which both almost no increase of TAT could be detected. In addition, the platelet activation showed a similar pattern with a 15-fold higher release of beta-TG in whole blood. In the in vitro chamber model with the clinically relevant materials, the fluoride-modified surface (TiOB-F) showed pronounced TAT generation compared with TiOB, mTi and HA. Similar results were achieved for platelet consumption and activation markers of the intrinsic coagulation system. Taken together these results implicate first that whole blood is necessary for sufficient thrombin generation and platelet activation during placement of implants. Second, a fluoride ion modification seems to augment the thrombogenic properties of titanium.
|
|
| 4. |
- Göransson, Anna, 1970, et al.
(författare)
-
Inflammatory response to titanium surfaces with fibrinogen and catalase coatings: an in vitro study.
- 2007
-
Ingår i: Journal of biomedical materials research. Part A. - : Wiley. - 1549-3296 .- 1552-4965. ; 80:3, s. 693-9
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of the present study was to evaluate the possibility to modulate the early inflammatory response in vitro by coating titanium surfaces with candidate proinflammatory (fibrinogen coated turned titanium "Fib") and antiinflammatory proteins (catalase on top of fibrinogen coated turned titanium "Cat"). Additionally, turned titanium surfaces (Ti) were used as controls. The discs were incubated with human mononuclear cells. Adhered cells were investigated with respect to number, viability, differentiation (acute marker 27E10 vs. chronic marker RM3/1), and cytokine production (TNF-alpha and IL-10), after 24 and 72 h. The results indicated that it is possible to modulate the inflammatory response with protein coatings. However, the strongest inflammatory response, indicated by increased number of adhered cells and release of pro and antiinflammatory mediators, was induced by Cat. Furthermore, the cytokine production on this surface was not sensitive to LPS stimulation. Differentiation measured as the expression of the chronic cell surface marker, dominated after 72 h for all surface modifications and Cat displayed an increased number compared to the others. A decrease in the total number of adhered cells and amounts of TNF-alpha were observed on all surfaces over time. The cell viability was, in general, high for all tested surfaces. In conclusion, the study proved it possible to influence the early inflammatory response in vitro by immobilizing protein coatings to titanium surfaces. However, the catalase surface demonstrated the strongest inflammatory response, and the possibility to selectively use the potent antiinflammatory capacity of catalase needs to be further evaluated.
|
|
| 5. |
- Reigstad, O., et al.
(författare)
-
Improved bone ingrowth and fixation with a thin calcium phosphate coating intended for complete resorption
- 2007
-
Ingår i: Journal of biomedical materials research. Part B, Applied biomaterials. - : Wiley. - 1552-4973 .- 1552-4981. ; 83B:1, s. 9-15
-
Tidskriftsartikel (refereegranskat)abstract
- Bonit is claimed to be a resorbable electrochemically deposited calcium phosphate coating consisting mainly of brushite, which is a hydroxyapatite precursor. This study involved a comparison of Ti6Al4V screw-shaped implants with and without a 15 +/- 5 microm Bonit coating in rabbit tibia and femur, after 6 and 12 weeks of insertion. The biomechanical removal torque test showed significantly increased values for the coated implants after 12 weeks (p < 0.05) but not after 6 weeks of integration. Higher bone-implant contact was found for the coated implants in the tibia after 6 weeks and for both tibial and femoral screws after 12 weeks (p < 0.05). There was no difference in the inflammatory reaction around the implants, and possible grains of the coating could be detected after 6 weeks, but not after 12 weeks of follow-up. This unloaded short-term study has shown promising results for the easily applicable and resorbable coat (Bonit) compared to uncoated titanium-alloy implants.
|
|
| 6. |
|
|
| 7. |
- Albrektsson, Tomas, 1945, et al.
(författare)
-
Oral Implant Surfaces 1
- 2005
-
Ingår i: Perio & Implant Quarterly 2005. ; 1, s. 33-43
-
Tidskriftsartikel (refereegranskat)
|
|
| 8. |
- Albrektsson, Tomas, 1945, et al.
(författare)
-
Oral Implant Surfaces 11
- 2005
-
Ingår i: Perio & Implant Quarterly 2005. ; 2, s. 22-49
-
Tidskriftsartikel (refereegranskat)
|
|
| 9. |
- Albrektsson, Tomas, 1945, et al.
(författare)
-
State of the art of oral implants
- 2008
-
Ingår i: Peridontology 2000. - : Wiley. - 1600-0757 .- 0906-6713. ; 47:1, s. 15-26
-
Tidskriftsartikel (refereegranskat)
|
|
| 10. |
- Albrektsson, Tomas, 1945, et al.
(författare)
-
The impact of oral implants - past and future, 1966-2042
- 2005
-
Ingår i: J Can Dent Assoc. - 1488-2159. ; 71:5
-
Tidskriftsartikel (refereegranskat)abstract
- This paper traces the history of oral implants, beginning with their early undocumented use in the mid-1960s. Although early experimentation with the Branemark system of osseointegration was unsuccessful, significant improvements and scrupulous documentation of the 1970s led to their general acceptance. George Zarb spearheaded their introduction into North America and application of the osseointegration technique soon expanded to extraoral craniofacial prostheses and bone-anchored hearing aids.New possibilities, such as altered surface properties and the use of implants in grafted and irradiated bone are currently being explored, although commercial pressure to introduce new products before they are adequately tested is a cause for concern.The future will see bioactive surfaces and additives that stimulate bone growth. In fact, with the possibility of in vivo growth of new teeth, implants may become unnecessary.
|
|
