| |  | AMENDMENTdated as of April 13, 2001 (the "Note Amendment") to the7% CONVERTIBLE SUBORDINATED NOTES(the "Notes") issued byGENTLE DENTAL SERVICE CORPORATION, a Washington corporation (the "Company"), in the aggregate principal amount of
$30,000,000.
| |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

WHEREAS,Section 9 of the Notes provides,inter alia, that each of the Notes may
be amended by the written consent of the Requisite Holders; and

WHEREAS,the Company and the Requisite Holders desire to amend each of the Notes to the extent set forth herein.

NOW, THEREFORE,in consideration of the foregoing, and for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged by the parties, the Company and the Requisite Holders, on behalf of themselves and each Purchaser and holder of a Note, hereby agree as follows:

1.  Each
of the Notes is hereby amended by deleting Section 2 in its entirety and substituting the following therefor:



2.  All
of the provisions of this Note Amendment shall be deemed to be incorporated in, and made a part of, each of the Notes, and each of the Notes, as supplemented
and amended by this Note

2

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Amendment shall be read, taken and construed as one and the same instrument. Except as otherwise expressly provided herein, each of the Notes shall remain in full force and effect and is hereby
ratified.

3.  All
of the agreements in this Note Amendment shall bind all successors and assigns, whether so expressed or not.

3

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IN WITNESS WHEREOF, the parties hereto have executed this Note Amendment as of the date first above written.

|                                         |  | GENTLE DENTAL SERVICE CORPORATION   
|---------------------------------------- |  | ------------------------------------
|                                         |  | By:                                 
|                                         |  |                                     
|Aggregate Principal Amount of Notes Held |  | REQUISITE PURCHASERS:               
|                                         |  | J.P. MORGAN PARTNERS (23A SBIC), LLC
|$15,000,000.00                           |  | By:                                 
|                                         |  | By:                                 
|                                         |  |                                     
|$209,998.75                              |  | DLJ CAPITAL CORP.                   
|                                         |  | By:                                 
|                                         |  |                                     

S1

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|$1,049,999.70 |  | DLJ FIRST ESC L.L.C.     
|------------- |  | -------------------------
|              |  | By:                      
|              |  | By:                      
|              |  |                          
|$5,051,520.90 |  | SPROUT CAPITAL VII, L.P. 
|              |  | By:                      
|              |  | By:                      
|              |  |                          
|$4,129,800.10 |  | SPROUT GROWTH II, L.P.   
|              |  | By:                      
|              |  | By:                      
|              |  |                          
|$58,680.55    |  | THE SPROUT CEO FUND, L.P.
|              |  | By:                      
|              |  | By:                      
|              |  |                          

S2

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| |  |  |  | Title: Attorney In Fact
| |  |  |  | -----------------------