FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * Sirona Holdings Luxco S.C.A.   2. Issuer Name and Ticker or Trading Symbol SIRONA DENTAL SYSTEMS, INC. [SIRO] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director __X__ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 412F, ROUTE D'ESCH, L-1030 3. Date of Earliest Transaction (Month/Day/Year) 08/06/2009 (Street) LUXEMBOURG, N4  4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) ___ Form filed by One Reporting Person _X_ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 08/06/2009   S   7,500,000 D $ 22.68 29,472,480 D (1) (2)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Sirona Holdings Luxco S.C.A. 412F, ROUTE D'ESCH L-1030 LUXEMBOURG, N4		X
Sirona Holdings S.A. 412F, ROUTE D'ESCH L-1030 LUXEMBOURG, N4		X
MDCP IV Global Investments LP C/O WALKERS SPV LIMITED PO BOX 908GT, MARY STREET GEORGE TOWN, E9		X
MDCP IV Global GP, LP C/O WALKERS SPV LIMITED, WALKER HOUSE PO BOX 908 GT, MARY STREET GEORGE TOWN, E9		X
MDP Global Investors LTD C/O WALKERS SPV LIMITED, WALKER HOUSE PO BOX 908GT, MARY STREET GEORGE TOWN, E9		X

Signatures

Sirona Holdings Luxco S.C.A., by Sirona Holdings S.A., its Manager, by /s/ Timothy Sullivan, its 'A' Director		08/06/2009
**Signature of Reporting Person		Date
Sirona Holdings S.A., by /s/ Timothy Sullivan, its 'A' Director		08/06/2009
**Signature of Reporting Person		Date
MDCP IV Global Investments LP, by MDP IV Global GP, LP, its General Partner, by MDP Global Investors Limited, its General Partner, by /s/ Timothy Sullivan, its Managing Director		08/06/2009
**Signature of Reporting Person		Date
MDP IV Global GP, LP, by MDP Global Investors Limited, its General Partner, by /s/ Timothy Sullivan, its Managing Director		08/06/2009
**Signature of Reporting Person		Date
MDP Global Investors Limited, by /s/ Timothy Sullivan, its Managing Director		08/06/2009
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	The following entities may be deemed to have a beneficial interest in the Common Stock held by Sirona Holdings Luxco S.C.A. ("Luxco"): Sirona Holdings S.A. ("Luxco Manager"), by virtue of its being the sole manager of Luxco; MDCP IV Global Investments LP ("MDCP IV Global Investments"), by virtue of its being the controlling shareholder of Luxco Manager; MDP IV Global GP, LP ("MDP IV Global GP"), by virtue of its being the sole general partner of MDCP IV Global Investments; and MDP Global Investors Limited by virtue of its being the sole general partner of MDP IV Global GP. A majority of the following members of MDP Global Investors Limited have the authority to vote or dispose of the shares held by MDCP IV Global Investments: John A. Canning, Jr., Paul J. Finnegan, Samuel M. Mencoff, Paul R. Wood,(Continued Footnote 2)
(2)	Benjamin D. Chereskin, Justin S. Huscher, James N. Perry, Jr., Thomas R. Reusche, Cynthia Reusche, Timothy P. Sullivan, Nicholas W. Alexos, Robin P. Selati, Gary J. Little GST Exempt Marital Trust, David F. Mosher and Thomas Souleles. Each of the members of MDP Global Investors Limited and each of MDCP IV Global Investments, MDP IV Global GP and MDP Global Investors Limited disclaims beneficial ownership of any shares directly held by Luxco except to the extent of their respective pecuniary interest therein.

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