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) 8-10, RUE MATHIAS HARDT (Street) L-1717 N4 NONE (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) 06/20/2006
	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	06/20/2006		P		36,972,480	A	(1)	36,972,480	I	See Footnote(2)(3)

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) 8-10, RUE MATHIAS HARDT (Street) L-1717 N4 NONE (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) 10, RUE HENRI M. SCHNADT (Street) L-2530 N4 NONE (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below) Sole manager of 10% holder

1. Name and Address of Reporting Person* MDCP IV Global Investments LP (Last) (First) (Middle) C/O WALKERS SPV LIMITED, WALKER HOUSE PO BOX 908GT, MARY STREET (Street) GEORGE TOWN, GRAND CAYMAN E9 NONE (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below) Primary shareholder of manager

1. Name and Address of Reporting Person* MDCP IV Global GP, LP (Last) (First) (Middle) C/O WALKERS SPV LIMITED, WALKER HOUSE PO BOX 908GT, MARY STREET (Street) GEORGE TOWN, GRAND CAYMAN E9 NONE (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below) Indirect GP of 10% owner

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, GRAND CAYMAN E9 NONE (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below) Indirect GP of 10% owner

Explanation of Responses:

1. Sirona Dental Systems, Inc. issued 36,972,480 shares of its Common Stock to Sirona Holdings Luxco S.C.A. ("Luxco") in exchange for 100% of the issued and outstanding share capital of Sirona Holding GmbH ("Sirona") and a Promissory Note issued June 30, 2005 by Sirona to Luxco in the original principal amount of <euro>150,992,464.

2. Owned by Luxco.

3. The following entities may be deemed to have a beneficial interest in the Common Stock held by 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.

	Sirona Holdings Luxco S.C.A., by Sirona Holdings S.A., its Manager, by /s/ Timothy Sullivan, its ''A'' Director	06/21/2006
	Sirona Holdings S.A., by /s/ Timothy Sullivan, its ''A'' Director	06/21/2006
	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	06/21/2006
	MDP IV Global GP, LP, by MDP Global Investors Limited, its General Partner, by /s/ Timothy Sullivan, its Managing Director	06/21/2006
	MDP Global Investors Limited, by /s/ Timothy Sullivan, its Managing Director	06/21/2006
	** Signature of Reporting Person	Date
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