Cresco™ is the easy-to-use solution for screw-retained implant bridges, providing freedom and a perfect fit every time. Cresco is available in different framework materials for all major implant systems. The technique is carefully described and clinical result are presented in the following summaries.
Early loading of Astra Tech OsseoSpeed implants placed in thin alveolar ridges and fresh extraction sockets
Purpose: Preclinical documentation has provided supporting evidence that the modification of a TiO2 gritblasted surface with fluoride leads to enhanced bone-to-implant contact with increased resistance to shear and tensile forces. In addition it is proposed that this OsseoSpeed'" surface promotes faster bone-to-implant contact.
The following report presents the interim data from the early clinical outcome of patients treated in a prospective clinical trial with OsseoSpeed™ implants in immediate extraction sockets and healed sites.
Material and Methods: A total of 18 patients, 9 male and 9 female were enrolled in the study receiving a total of 65 implants into both healed (n = 36) and immediate extraction (n = 29) sites. Both maxilla and mandible were treated in a 60/40 ratio. Patients were free of systemic disease, with no obstacles to surgery under local anesthesia. For extraction sockets the implants were located 1 mm below the buccal crest, placing them deep to the interproximal and lingual crest of bone. For healed sites, where ridges were generally narrow, a deep placement was also utilized to avoid too much thread exposure. Where dehiscence or circumferential socket defects remained a mix of bone from the BoneTrap™ and bio-glass was used as a graft.
For implants to remain included in the study an adequate primary stability was necessary for early functional restoration within 3 months of placement. Impressions were typically taken 2 weeks post-op and prostheses inserted within 5 weeks of surgery as a mean. Prostheses included single-tooth replacements as well as screw-retained partial and full arch prostheses, fabricated utilizing the Cresco'" method.
Follow-up was staged at 6 and 12 months post insertion of the final prostheses, with standardized radiographs used to compare measures of the bone level to a fixed reference point at the base of the coronal bevel of the implant with those recorded at baseline, on prosthesis insertion. All assessments were undertaken at x7 magnification to the nearest 0.1 mm. Clinical follow-up also included an assessment of plaque score, mucosal index, pocket probing depths and registration of any mechanical problems.
Results: One implant was lost due to infection giving a 1-year survival rate of 98.5%. For 78% of sites there was no evidence of mucosal inflammation, with generally good plaque control. There was no discernable peri-implant mucositis as evidenced by deep pocketing or radiographic evidence of bone loss, with changes in the marginal bone level of 0.1 mm from baseline to the 1-year follow-up. Furthermore there were no differences between the groups for implants in healed sites or extraction sockets.
In addition it was of interest to note that there were no mechanical problems recorded, and no episodes of screw loosening with the Cresco™ Precision prostheses.
Discussion and Conclusions: Unlike previously published data there was no evidence in the current study of any early bone loss which could be attributed to the new fluoridated surface technology. However it is recognized that it is difficult to extrapolate radiographic interpretation of bone levels to the real situation due to their 2-dimensional nature and in the current study due to the difficulty in differentiating between native bone and the graft, when used. Nonetheless within the context of previous studies, which use the same methodology, and in light of the absence of clinical signs of inflammation or pocketing the data is encouraging.
In addition it is very encouraging to note that prostheses could be connected to the implants as early as 5 weeks post insertion, secured to 25 Ncm without inducing early failure due to stresses from non-passive frameworks. This is certainly due to the accurately fitting Cresco™ Precision prosthetic method, which ensures absolute passivity of fit.
It can be concluded that OsseoSpeed™ implants can be subjected to early loading when restored with Cresco1" Precision fit prostheses.
Astra Tech
BioManagement Complex 
