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.
A prospective 5-year multicenter study of the Cresco implantology concept
Purpose: The aim of this study was to evaluate the clinical and radiographic outcome for implants restored with an abutmentfree passive fitting Cresco bridge.
Material and Methods: The implants used in the current study were the Cresco API implants presenting with an acid etched surface and an internal conical interface with a 45-degree taper allowing for implant mal-alignments up to 90 degrees. Implant diameters were 3.3 mm, 3.7 mm and 4.5 mm. No abutments were utilized in the system; rather a definitive metal framework was fabricated to derive direct connection to the implants by means of 2mm diameter connecting screws.
Fixture-head impressions allow for plastic mouldable sleeves to be connected to the replicas and bent into the long axis of the teeth, with occlusal access being placed favourably within the occlusal table or palatally for anterior implants. Off-set angles of up to 17 degrees can be corrected in this way. Subsequent to registration of the cylinder positions in an articu-lator-like "fixator", prefabricated titanium cylinders are then used to replace the plastic sleeves and these milled parallel to the opposing cast titanium framework to which they are then laser welded to ensure a passive fit.
A total of 60 patients were treated by means of a two-stage surgical approach at 3 centers, for the rehabilitation of 6 edentulous maxillae, 11 mandibles and 43 partial saddles of which 32 were mandibular. Of the patients enrolled only 52 were available for follow-up at 5 years.
A full preoperative assessment included an evaluation of bone density and volume according to the Lekholm/Zarb classification. Patients were followed up at 12 and 18 months and then at 2 , 3, 4, and 5 years in order to evaluate the presence of any symptoms and to assess soft tissue health, implant stability, mechanical stability and changes in marginal bone levels as determined from intraoral radiographs taken in customised paralleling devices. Radiographs were critically appraised to the nearest 0.1mm at x7 magnification with an in-built millimetre graticule.
Results: A total of 215 implants were utilized in the study of which 4 failed to integrate, and a total of 211 were available for review at the 5-year follow up. Patients reported a high level of satisfaction with the only symptoms related to minor soft tissue problems, which was reflected in a general healthy soft tissue scoring with only 15% of sites recording bleeding on light pressure. There was no evidence of peri-implant infections.
Three retaining screws fractured after 21 months in one subject restored with a full mandibular fixed bridge, and 2 screw fractured in one subject restored with a 3-unit FPD. This patient had been totally unaware of the bridge mobility and had failed to attend the previous follow-up. Unfortunately both the prosthesis and 2 implants thus required removal. This gave an implant survival rate after loading of 98.5%, and a prosthesis survival rate of 98.1%.. Resin fracture occurred in 2 cases, and one laser welded joint fractured requiring laboratory repair.
Mean marginal bone loss measured 0.3 mm after 5 years of function.
Discussion: The current study was meant to evaluate the Cresco concept giving due consideration to both the implant and restorative components, to be evaluated over a 5 year time frame. In this respect the clinical and radiographic outcome demonstrated the Cresco system to be comparable to other systems reported. The flexibility of the Cresco system allows for the realignment of screw access holes up to 17 degrees, aiding their relocation away from the buccal surface when implants have a buccal inclination and also ensuring a more passive framework fit. The current study would support this with a very low rate of mechanical problems with less than 2% of problems related to the retaining screws after 5 years of function.
The radiographic follow-up certainly demonstrates a marginal bone maintenance that fulfils currently accepted criteria for success, giving an implant survival rate of 98.5% which is comparable to other marketed implant systems. It can therefore be concluded that the current 5-year results demonstrate that the Cresco system is efficacious in the restoration of partially and fully edentulous jaws.
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BioManagement Complex 
