UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 11, 2009

SIRONA DENTAL SYSTEMS, INC.

(Exact name of Registrant as specified in its charter)

(718) 937-5765

(Registrant’s telephone number, including area code)

N/A

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

On December 11, 2009, Sirona Dental Systems, Inc. (the “Company”) entered into an Underwriting Agreement (the “Underwriting Agreement”), by and among the Company, Sirona Holdings Luxco S.C.A. (“Luxco”), Jeffrey T. Slovin (and together with Luxco, collectively, the “Selling Stockholders”) and Barclays Capital Inc. in connection with the offering of 7,350,000 shares of the Company’s common stock (the “offering”), sold by the Selling Stockholders at a price per share of $32.15. Pursuant to the Underwriting Agreement, the underwriters also have a 30-day option to purchase up to an additional 1,102,500 shares of common stock from Luxco to cover over-allotments, if any. The Company will not receive any proceeds from the offering.

The offering will be made only by means of a prospectus supplement and accompanying base prospectus, copies of which may be obtained from: Barclays Capital Inc., c/o Broadridge, Integrated Distribution Services, 1155 Long Island Avenue, Edgewood, New York 11717; Barclaysprospectus@broadridge.com (phone: 888-603-5847). A copy of the prospectus supplement and accompanying base prospectus may also be obtained at no charge at the U.S. Securities and Exchange Commission’s website, at www.sec.gov.

The shelf registration statement relating to the foregoing has previously been filed with, and declared effective by the U.S. Securities and Exchange Commission. This Form 8-K does not constitute an offer to sell or a solicitation of an offer to buy the shares of Sirona’s common stock or any other securities, nor will there be any sale of the shares of Sirona’s common stock or any other securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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