Exhibit 4.11

AMENDMENT
NO. 2 TO
ASSET PURCHASE AGREEMENT

AMENDMENT
NO. 2 TO ASSET PURCHASE AGREEMENT (the "Second Amendment"), dated as of May 23, 2001, among CORE-VENT CORPORATION, d/b/a Paragon Implant Company, a Nevada
corporation ("Paragon"), CORE-VENT BIOENGINEERING, INC., a California corporation ("C-V BioEngineering"), CORE-VENT PARAGON BIO, a California corporation
("C-V Paragon"), PARAGON ADMINISTRATION, INC., a California corporation ("Paragon Administration"), CORE-VENT GmbH, a corporation organized under the laws of the Federal
Republic of Germany ("C-V GmbH"), CORE-VENT ISRAEL (1997), a PARAGON Company Ltd., a corporation organized under the laws of Israel ("C-V Israel"; and
together with Paragon, C-V BioEngineering, C-V Paragon, Paragon Administration, C-V GmbH and C-V Israel, the "Seller"), the shareholders of Paragon
identified on the signature page hereof (the "Paragon Shareholders"), the shareholders of C-V BioEngineering identified on the signature page hereof (the "C-V BioEngineering
Shareholders"), the Niznick Family Foundation (the "Niznick Foundation"), a California not-for-profit corporation, DR. GERALD A. NIZNICK, an individual ("Dr. Niznick";
and together with the Paragon Shareholders, the C-V BioEngineering Shareholders and the Niznick Foundation, the "Shareholders"), SULZER MEDICA USA INC., a Delaware corporation
("Parent"), SULZER DENTAL INC. (formerly known as Sulzer Calcitek Inc.), a Delaware corporation ("Calcitek") and SULZER DENTAL GmbH (formerly known as Sulzer Calcitek GmbH.), a
corporation organized under the laws of the Federal Republic of Germany ("Calcitek GmbH"), SULZER DENTAL LTD., a corporation organized under the laws of Israel ("Calcitek Israel") and SULZER
DENTAL CORP, a corporation organized under the laws of Canada ("Calcitek Canada" and together with Calcitek, and Calcitek GmbH and Calcitek Israel, the "Purchaser").

W
I T N E S S E T H:

WHEREAS,
the Seller, the Shareholders, Parent and Purchaser entered into (i) the Asset Purchase Agreement dated November 1, 2000, pursuant to which Seller agreed to sell
and Purchaser agreed to purchase the Assets, all as more particularly set forth therein and (ii) Amendment No. 1 to Asset Purchase Agreement dated January 8, 2001, (as so amended,
the "Asset Purchase Agreement") pursuant to which Seller agreed to modify certain of the terms of the original Asset Purchase Agreement, all as more particularly set forth therein;

WHEREAS,
the parties hereto wish to further amend the Asset Purchase Agreement by executing this Amendment No. 2 to Asset Purchase Agreement all as more particularly set forth
herein.

NOW,
THEREFORE, in consideration of the premises and the mutual agreements and covenants hereinafter set forth, and intending to be legally bound hereby, the parties hereby agree as
follows:

1.Definitions.Capitalized terms used herein without definition shall have the meanings ascribed to such terms
in the Asset Purchase Agreement.

2.Amendments.The parties hereby agree to amend the Asset Purchase Agreement as follows:

(a)    In
Section 2.08(b)(ii), the first sentence is deleted in its entirety and replaced with the following: "The Seller may dispute any amounts reflected on the
Closing Balance Sheet, provided that the Seller shall have notified the Purchaser and the Purchaser's Accountants in writing of each disputed item, specifying the estimated amount thereof in dispute
and setting forth, in reasonable detail, the basis for such dispute, on or before the latter of June 30, 2001 or 30 days after an initial meeting with Purchaser and/or Purchaser's
Accountants to discuss the Closing Balance Sheet. In the event that Seller identifies disputed amounts, Seller and Purchaser will begin discussions in an attempt to identify the Independent Accounting
Firm."

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(b)    In
Section 2.08(c), clause (A) is deleted in its entirety and replaced with the following: "(A) the failure of Seller to notify the Purchaser and the
Purchaser's Accountants as provided in clause (ii) of Section 2.08(b),".

(c)    In
Section 2.08(c)(ii), the second paragraph is deleted in its entirety and replaced with the following: "Notwithstanding the foregoing, on or before
May     , 2001, Purchaser will (A) deliver instructions to the Escrow Agent to distribute to the Seller the Adjustment Escrow Funds, net of the Seller's share of the Escrow
Agent's estimated fees; and (B) deliver to Seller the amount by which the Closing Date Net Assets reflected on the draft Closing Balance Sheet sent to Seller on May 8, 2001 exceeds
$12,000,000 plus any interest payable pursuant to Section 2.08(d). Any amount so distributed shall be offset against the amounts, if any, payable to Seller pursuant to the procedures set forth
in Section 2.08(c)(i) and 2.08(c)(ii)."

3.Name Changes.

(a)    Sulzer
Calcitek Inc. has changed its name to "Sulzer Dental Inc.". All references in the Asset Purchase Agreement and its amendments to "Calcitek" shall be
references to Sulzer Dental Inc.

(b)    Sulzer
Calcitek GmbH. has changed its name to "Sulzer Dental GmbH". All references in the Asset Purchase Agreement and its amendments to "Calcitek GmbH" shall be
references to Sulzer Dental GmbH.

4.No Further Modifications.Except as expressly set forth herein, the terms and provisions of the Asset
Purchase Agreement remain unmodified and in full force and affect.

5.Miscellaneous.

(a)    This
Second Amendment shall be governed by, and construed in accordance with, the laws of the State of California, applicable to contracts executed in and to be
performed entirely in that state.

(b)    This
Second Amendment may be executed in one or more counterparts, and by the different parties hereto in separate counterparts, each of which when executed shall be
deemed to be an original but all of which taken together shall constitute one and the same agreement.

IN
WITNESS WHEREOF, the parties hereto have executed, or have caused this Agreement to be executed by their respective officers thereunto duly authorized, as of the date first written
above.

| |  | CORE-VENT CORPORATION,
d/b/a Paragon Implant Seller                     
| |  | ------------------------------------------------------------------------
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President
| |  | CORE-VENT BIOENGINEERING, INC.                                          
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President
| |  | CORE-VENT PARAGON BIO                                                   
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President
| |  | PARAGON ADMINISTRATION, INC.                                            

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| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President                          
| |  | --------------------------------------------------------------------------------------------------
| |  | CORE-VENT GmbH                                                                                    
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President                          
| |  | CVPBE, Inc.                                                                                       
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President                          
| |  | CV Equipment, Inc.                                                                                
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President                          
| |  | PARAGON DENTAL IMPLANT, LTD.                                                                      
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: President                          
| |  | THE PARAGON SHAREHOLDERS                                                                          
| |  | By: /s/DR. GERALD A. NIZNICKDr. Gerald A. Niznick                                                 
| |  | THE C-V BIOENGINEERING STOCKHOLDERS                                                               
| |  | By: /s/DR. GERALD A. NIZNICKDr. Gerald A. Niznick                                                 
| |  | THE NIZNICK FOUNDATION                                                                            
| |  | By: /s/DR. GERALD A. NIZNICKName: Dr. Gerald A. Niznick
Title: Director                           
| |  | SULZER MEDICA USA INC.                                                                            
| |  | By: /s/DAVID S. WISEName: David S. Wise
Title: Group Vice President, General Counsel and Secretary
| |  | SULZER DENTAL INC.                                                                                

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| |  | By: /s/STEVEN E. HANSONName: Steven E. Hanson
Title: President
| |  | --------------------------------------------------------------
| |  | SULZER DENTAL GmbH                                            
| |  | By: /s/STEVEN E. HANSONName: Steven E. Hanson
Title: President
| |  | SULZER DENTAL LTD.                                            
| |  | By: /s/STEVEN E. HANSONName: Steven E. Hanson
Title: President
| |  | SULZER DENTAL CORP.                                           
| |  | By: /s/STEVEN E. HANSONName: Steven E. Hanson
Title: President

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