 Astra Tech
BioManagement Complex
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 Osseo Speed
OsseoSpeed™ is the implant with a chemically modified surface and a unique nanoscale topography. The OsseoSpeed implant has clearly improved results compared to earlier generations of implants. The following summaries of the pre-clinical and clinical scientific articles reveal the mechanisms behind the performance and clinical outcome.
 Three-year post-loading outcomes with MicroThread OsseoSpeed dental implants placed in the posterior maxilla
It has been established that bone volume and density can variously affect primary implant stability and implant success rates. In particular it has been shown that higher failures rates can be expected in the pos-terior maxilla where bone density is often low. In an effort to address these problems the use of osteotomes for sinus lift procedures is said to increase both bone volume by increasing height, as well as density by the lateral compaction of bone trabeculae. However there is also data which suggests this may damage the bone resulting in delayed healing and crestal bone loss.
With the application of nanotechnology and the recent introduction of fluoride modified, moderately roughened surfaces (OsseoSpeed"), which have been shown to have an affinity for up-regulating the activity of osteoblasts and the expression of key genes responsible for the production of mineral matrix, it is proposed that implants with these new surfaces can demonstrate high success even in posterior maxilla.
Purpose: This study aimed to present 3-year data for OsseoSpeed implants placed in the posterior maxilla restored using a rapid loading protocol.
Materials and Methods: Twenty patients with missing maxillary molars and premolars were enrolled to the study if the residual bone height was < 5 mm in height to the sinus floor and < 6 mm in width. All implants were placed using an osteotome technique and benefitted from transmucosal healing with connection of a บทi-Abutment at time of surgery. All implants were assessed for primary stability using resonance frequency analysis (RFA) to measure the implant stability quotient (ISQ). After 6 weeks of unloaded healing for osseointegration all implants were restored and placed into functional occlusion with a temporary acrylic restoration. This was converted to a definitive prosthesis at one year. Clinical parameters were scored for plaque, gingival index, implant mobility, and bleeding on probing at 4, 8,12, 26, and 52 weeks and annually thereafter, along with repeated measurements of ISQ.
Radiographic analysis was performed by taking standardized intra-oral radiographs at implant placement, 3, 6,12,24 and 36 months postloading. Images were digitized and bone levels measured to within 0.1 mm by an independent radiologist.
Results: A total of 59 implants were inserted into bone graded as quality 4 in 56% of sites, and quality 3 in 34% of sites according to surgeon interpretation. 34 implants were placed in association with an internal sinus lift to increase bone height an average of 4.1 mm. The most common implant length was 11 mm with 27% being shorter that 10 mm. Two implants failed within the first 5 months and another one failed after nearly 2.5 years to yield an overall survival rate of 95%. In 6 subjects loading was delayed due to lack of implant stability even after 6 weeks, however all these implants still went on to osseointegrate. ISQ values were seen to change with time during the first year of loading but not there-after, p < 0.05. The increase was more marked for implants placed in types 3 and 4 bone.
Regarding marginal bone data, the majority of bone loss occurred in the first year and stabilized there¬after. The mean marginal bone loss was -0.12 mm +/- 0.37 mm at the mesial side and -0.25 mm +/- 0.54 mm at the distal side. 80% of all implants demonstrated minimal bone loss over time.
Discussion and Conclusion: The literature has shown that the use of osteotomes can increase primary implant stability and this was supported by the current study. However the use of an implant with specific design features aimed at maintaining crestal bone may be necessary to prevent crestal bone resorption seen when using this technique, especially in the posterior maxilla. However bone maintenance was apparent in 80% of this study sample. The higher bone loss noted distally is unexplained but is a phenomenon reported elsewhere (Norton, 2006). Current data further support the widely published maintenance of marginal bone seen with the Astra Tech implant.
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