In fact, we have further empowered our accomplished R&D team by opening our brand-new, state-of-the-art, center of innovation in Bensheim, Germany. This exceptional facility is a testament to why we think Sirona is ideally positioned to continue our tradition of leading the way with innovation for the dental industry. We are extremely excited to see what will emerge from our newly commissioned facility.
In fiscal 2011, Sirona invested heavily in expanding its global sales and service infrastructure with major initiatives in Japan, Russia and Korea, to name but a few. These investments were a key driver for our strong international growth. Clearly, this strategy is paying substantial dividends. Importantly, the two prong strategy of our commitment to innovation supported by an expanding global sales and service organization is delivering strong results.
Imaging was our best performing segment in fiscal 2011, up 24.8% constant currency. With strong performance from our Orthophos XG 3D and 3D imaging systems.
In 3D imaging, Sirona is the global leader. CAD/CAM increased 15.9%, benefiting from the continuous international build out of our sales and services infrastructure and the successful trading programs in Germany and the U.S.Treatment centers increased 10.2%; revenue growth was particularly driven by non-European international markets. And instruments increased 5.6%. International revenues increased 20.5% constant currency with Germany, other European markets and other world markets all increasing at solid, double-digit rates. For the U.S., our revenues increased 6.8% with particularly strength in the imaging segment. In addition to our strong revenue growth, we also made progress in expanding our margin. SG&A as a percent of sales, excluding the one-time charge, declined 100 basis points to 29.6%. In our operating income, excluding amortization as a one-time charge was 222.5 million, up 17.8% compared to 2010. All of our hard work translated into solid free cash flow, a total of 121.9 million in financial year ‘11. We used this cash to reduce our net debt by 96.4 million, deleveraging our balance sheet and strengthening our financial position for the future. Read the rest of this transcript for free on seekingalpha.com