SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Sirona Holdings Luxco S.C.A. (Last) (First) (Middle) 412F, ROUTE D'ESCH L-1030 (Street) LUXEMBOURG N4 (City) (State) (Zip)	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)
	3. Date of Earliest Transaction (Month/Day/Year) 08/06/2009
	4. If Amendment, Date of 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

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)

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 Securities Underlying Derivative Security (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: 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

1. Name and Address of Reporting Person* Sirona Holdings Luxco S.C.A. (Last) (First) (Middle) 412F, ROUTE D'ESCH L-1030 (Street) LUXEMBOURG N4 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* Sirona Holdings S.A. (Last) (First) (Middle) 412F, ROUTE D'ESCH L-1030 (Street) LUXEMBOURG N4 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MDCP IV Global Investments LP (Last) (First) (Middle) C/O WALKERS SPV LIMITED PO BOX 908GT, MARY STREET (Street) GEORGE TOWN E9 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MDCP IV Global GP, LP (Last) (First) (Middle) C/O WALKERS SPV LIMITED, WALKER HOUSE PO BOX 908 GT, MARY STREET (Street) GEORGE TOWN E9 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MDP Global Investors LTD (Last) (First) (Middle) C/O WALKERS SPV LIMITED, WALKER HOUSE PO BOX 908GT, MARY STREET (Street) GEORGE TOWN E9 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

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.

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