EXHIBIT 10.1

Confidential Treatment Requested

Pursuant to Rule 24b-2

Certain portions of this exhibit, as indicated by “[+++]”, have been omitted,
pursuant to a request for confidential treatment under Rule 24b-2 of the
Securities Exchange Act of 1934. The omitted materials have been filed
separately with the Securities and Exchange Commission.

AMENDMENT TO CONSOLIDATED AND RESTATED AMENDMENT TO DISTRIBUTORSHIP AGREEMENT

THIS AMENDMENT to the Consolidated and Restated Amendment to Distributorship
Agreement (this “Amendment”) is made and entered as of May 3, 2011, between
PATTERSON COMPANIES, INC., a Minnesota corporation (“Patterson”) and SIRONA
DENTAL SYSTEMS GMBH, a limited liability company organized under the laws of the
Federal Republic of Germany (“Sirona”). Patterson and Sirona are sometimes
collectively referred to as the “Parties” and each individually as a “Party”.

WHEREAS, the Parties entered into a Distributorship Agreement dated by Patterson
April 24, 1998 and dated by Sirona April 27, 1998 (the “Distributorship
Agreement”);

WHEREAS, the Parties entered into a Consolidated and Restated Amendment to
Distributorship Agreement dated as of June 30, 2005 (the “Consolidated and
Restated Amendment”); and

WHEREAS, the Parties desire by this Amendment to amend the Consolidated and
Restated Amendment.

NOW, THEREFORE, in consideration of the above premises and the mutual covenants
in this Amendment, and for other good and valuable consideration, given by each
Party to the other, the sufficiency and receipt of which are hereby
acknowledged, the Parties, for themselves, their successors and permitted
assigns, intending to be legally bound, agree that the Consolidated and Restated
Amendment be amended as follows:

I. Dental Lab Products. Section IV of the Consolidated and Restated Amendment is
deleted in its entirety and is replaced by the following provisions:

IV. inLab Products.

A. “inLab Products” shall mean Contractual Products offered by Sirona
specifically for dental laboratory use. inLab Products shall include all CAD/CAM
equipment made by Sirona under the inLab product line including inLab MC XL,
inLab (compact milling unit), inLab PC and monitor, inEos Blue scanner, inLab 3D
software, and any other product that Sirona may introduce under the inLab line.
For the avoidance of doubt, inLab Products shall not include infiniDent products
and CEREC Connect.

B. The “Sirona Lab Market” shall comprise all commercial laboratories in the
Territory that do not reside within a dental practice with the sole purpose of
serving such dental practice or affiliated practices. The “Patterson Lab Market”
shall comprise dental laboratories in the Territory that reside within a dental
practice and the sole purpose of which is to serve such dental practice or
affiliated practices (together with the Sirona Lab Market, the “Lab Market”).

C. Sirona and Patterson shall each use best efforts in the sale and promotion of
the inLab Products. Sirona shall be responsible for training, marketing and
promoting the sale of the inLab Products in the Sirona Lab Market. Patterson
shall be responsible for invoicing, installing, servicing and supporting the
inLab Products in the Sirona Lab Market. Patterson shall be responsible for
training, marketing, promoting, invoicing, installing, servicing and supporting
the inLab Products in the Patterson Lab Market. Notwithstanding anything to the
contrary in Section 5 of the Distributorship Agreement, Patterson shall provide
to Sirona a monthly sales report for the Lab Market within one week after the
end of each month. For the avoidance of doubt, Patterson shall sell consumable
products, including, without limitation, Blocks for the inLab Products and other
sundry items related to the inLab Products, in the Lab Market. Further,
Patterson’s exclusive right to distribute Contractual Products in the Territory
to end users shall apply to inLab Products. Sirona and its representatives shall
not participate in Lab Market programs with other distributors without
Patterson’s prior written consent.

D. Notwithstanding anything to the contrary in Section 6 of the Distributorship
Agreement, Sirona shall be responsible for conducting training sessions for the
inLab Products in the Sirona Lab Market. Such training

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shall be provided directly by Sirona or, at Sirona’s discretion, with the
support of Sirona’s manufacturing partners and all costs associated with such
training shall be paid by Sirona. Patterson shall be responsible for conducting
training sessions for the inLab Products in the Patterson Lab Market and shall
pay all costs associated with such training.

E. Notwithstanding anything to the contrary in Section 8.5 of the
Distributorship Agreement, Sirona shall provide a three year warranty on parts
of the inLab Products and Patterson shall provide a 90-day labor warranty.

F. The Parties agree that a service club for the inLab Products will be
established on or before December 31, 2011 pursuant to terms and conditions to
be agreed upon by the Parties. Margins derived from the operations of such
service club will be split between the Parties, with [+++] to Sirona and [+++]
to Patterson.

II. Annex 3 to Distributorship Agreement. The line item relating to inLab
Products in Annex 3 to the Distributorship Agreement is deleted and is replaced
with Annex 3-inLab Products attached as Exhibit A hereto.

III. Successors Bound. This Amendment shall inure to the benefit of and be
binding upon the successors to the Parties.

IV. Headings. The captions, headings and titles used in this Amendment are for
convenience of reference only and will not affect in any way the meaning or
interpretation of this Amendment.

V. Counterparts. This Amendment may be executed in multiple counterparts, which
shall be deemed to be one and the same instrument and each of which shall be
deemed enforceable without production of the others.

VI. Full Force and Effect. Except as expressly amended hereby, the Consolidated
and Restated Amendment remains in full force and effect.

 

(signature page follows)

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IN WITNESS WHEREOF, the undersigned have caused this Amendment to be duly
executed as of the date first above written.

 

PATTERSON COMPANIES, INC. By:       /s/ Paul A. Guggenheim Name:       Paul A.
Guggenheim Title:       President

 

SIRONA DENTAL SYSTEMS GMBH By:       /s/ Bart Doedens Name:       Bart Doedens
Title:       Vice President       Dental CAD/CAM Systems By:       /s/ Joachim
Pfeiffer Name:       Joachim Pfeiffer Title:       Vice President       Dental
CAD/CAM Systems

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EXHIBIT A

Annex 3—inLab Products to Distributorship Agreement

Prices of inLab Products

Sirona Lab Market

 

inLab Product

   MSRP

Equipment and Software

   *

Digital Impressions

   *

Patterson Lab Market

 

inLab Product

   MSRP

Equipment and Software

   *

Digital Impressions

   *

Agreed Patterson Discount from Retail:

 

Product

   Patterson Discount from MSRP*

Equipment and Software into Sirona Lab Market

   [+++]

Equipment and Software into Patterson Lab Market

         [+++] **

Digital Impression Systems

   [+++]

Sales into Group Practices of all Sirona Equipment

   [+++]

 

* MSRP means the price set forth on the then current Sirona/Patterson inLab
price list.

** Patterson will purchase all inLab Equipment from Sirona at the Sirona Lab
Market Pricing. Patterson will provide reconciliation with proof of actual sales
(copies of invoices) into the Patterson Lab market once per quarter and Sirona
will rebate the additional margin on such sales within 30 days of receipt of
such reconciliation.