Exhibit 4.18

ALL INDEBTEDNESS  EVIDENCED HEREBY AND REFERENCED HEREIN IS SUBJECT TO THE TERMS
OF THAT CERTAIN  SUBORDINATION  AGREEMENT AMONG BRIDGE HEALTHCARE FINANCE,  LLC,
BRIDGE  OPPORTUNITY  FINANCE,  LLC, THE HOLDER UNDER THIS DOCUMENT AND THE OTHER
PARTIES NAMED THEREIN.

THIS  SUBORDINATED  PROMISSORY NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES
ACT OF 1933, AS AMENDED (THE  "SECURITIES  ACT") OR THE SECURITIES,  BLUE SKY OR
OTHER APPLICABLE LAWS OF ANY STATE, OR ANY OTHER RELEVANT JURISDICTION,  AND MAY
NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS IT
IS (A) REGISTERED AND/OR QUALIFIED  PURSUANT TO THE RELEVANT  PROVISIONS OF U.S.
FEDERAL  SECURITIES LAWS, THE SECURITIES,  BLUE SKY, OR OTHER APPLICABLE LAWS OF
ANY STATE, OR OTHER RELEVANT  JURISDICTION OR (B) EXEMPT FROM SUCH  REGISTRATION
OR QUALIFICATION.

                         SUBORDINATED PROMISSORY NOTE

$______________ - Principal Amount                   Issue Date - March 29, 2005

      FOR VALUE  RECEIVED,  Crdentia Corp, a Delaware  corporation  ("OBLIGOR"),
hereby  promises  to pay to the  order  of  ____________  or  permitted  assigns
("HOLDER"),  in lawful  money of the United  States at the address of Holder set
forth below,  the principal sum of On Million Six Hundred Seven  Thousand  Seven
Hundred Forty Five and No/100  Dollars  ($1,617,745.00),  together with interest
thereon  as  provided  in this  Convertible  Subordinated  Promissory  Note (the
"NOTE") on the unpaid  principal  balance.  Interest  shall  accrue at a rate of
seven and three quarters percent (7.75%), simple interest, until paid in full.

      Unpaid  principal  under this Note  together  with all  accrued and unpaid
interest  shall be paid to Holder  (subject to the  provisions  of the following
paragraph)  as follows:  (i)  beginning on April 30, 2005 and  continuing on the
last day of each month through  September 30, 2005,  Obligor shall make payments
to Holder of interest only and (ii) beginning on October 31, 2005 and continuing
on the last day of each month  through the  Maturity  Date (as herein  defined),
Obligor shall make a total of thirty (30) equal, consecutive monthly payments to
Holder each in the amount of Fifty-Nine  Thousand One Hundred  Twenty-Three  and
5/100 Dollars  ($59,123.05).  All  outstanding  principal and accrued and unpaid
interest  shall be due and  payable  in full on March 31,  2008  (the  "MATURITY
DATE").  Notwithstanding the foregoing, this Note may be prepaid, in whole or in
part, at any time without premium or penalty.

      This Note is one of a series  issued by Obligor  pursuant  to the terms of
that certain  Agreement and Plan of Reorganization  (the "MERGER  AGREEMENT") by
and among Obligor,  CRDE Corp.,  TravMed Acquisition  Corporation,  TravMed USA,
Inc. and the Shareholders  (as defined in the Merger  Agreement) of TravMed USA,
Inc.  dated March 28, 2005.  This Note is subject to the  provisions  of Section
9.3(a) of the Merger Agreement.


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<PAGE>


      If any payment of  principal or interest on this Note shall become due and
on a Saturday, Sunday, or a public holiday under the laws of the State of Texas,
such payment shall be made on the next succeeding business day.


      The indebtedness  evidenced by this Note is hereby subject to the terms of
that certain  Subordination  Agreement  date of even date  herewith by and among
Obligor, Holder, Bridge Healthcare Finance, LLC, Bridge Opportunity Finance, LLC
and other parties named therein.

      Subject to and upon compliance with the provisions contained in this Note,
at the option of the Holder,  the principal amount of this Note may be converted
in whole or in increments of not less than $500,000 in principal into fully paid
and nonassessable  shares of common stock, $.0001 par value (the "COMMON STOCK")
of the  Obligor  at the  conversion  price of $2.06 per share  (the  "CONVERSION
PRICE").  Such  conversion  right  shall  expire at the close of business on the
Maturity Date. In case this Note is called for early prepayment, such conversion
right shall expire at the close of business on the second business day preceding
the date set for prepayment,  unless the Obligor  defaults in making the payment
then due.

      In order to exercise  the  conversion  privilege,  the Holder of this Note
shall surrender the original of this Note, along with a Conversion Notice in the
form  attached  hereto as Exhibit  "A",  at the  Obligor's  principal  executive
offices.

      This  Note,  or  the  principal  amount  converted  as  set  forth  in the
Conversion  Notice shall be deemed to have been converted  immediately  prior to
the close of business on the date of  surrender of this Note for  conversion  in
accordance with the foregoing  provisions (the "CONVERSION  DATE"),  and at such
time the rights of the Holder in this Note for repayment of the principal amount
so converted shall cease, and the Holder shall be entitled to receive the Common
Stock  issuable  upon  conversion  and shall be treated for all  purposes as the
record  holder or holders of such  Common  Stock at such time.  As  promptly  as
practicable on or after the  Conversion  Date, the Obligor shall issue and shall
deliver to the Holder (i) a certificate or  certificates  for the number of full
shares of Common Stock issuable upon  conversion,  together with payment in cash
in lieu of any fraction of a share and (ii) a new  subordinated  promissory note
in the form of this Note (the "NEW NOTE") for the remaining  principal amount of
this Note which has not been converted  pursuant to the Conversion  Notice.  The
New Note  will  call for  payments  of  principal  and  interest  following  the
Conversion  Date  which  reamortizes  the  principal  amount  of the  Note  then
remaining  outstanding  over the  original  term of the Note  (such  New Note to
commence  amortization  effective  October 31, 2005 if the Note is  converted in
part prior to such date)

      In the event  Obligor  shall issue  additional  shares of Common  Stock by
reason of a stock dividend or distribution or in any manner  subdivide (by stock
split,  stock exchange or otherwise) the outstanding shares of Common Stock into
a greater  number of shares of Common Stock or combine (by reverse  stock split,
stock  exchange or  otherwise)  the  outstanding  shares of Common  Stock into a
lesser  number  of  shares  of  Common  Stock,  the  Conversion  Price in effect
immediately  prior  thereto  shall be  adjusted  so that the Holder of this Note
thereafter surrendered for conversion shall be entitled to receive the number of
shares of Common  Stock which such holder  would have owned or been  entitled to
receive  after the happening of any of the events  described  above if this Note
had been converted  immediately  prior to the happening of such event on the day


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<PAGE>


upon which such event becomes  effective.  In the  provisions of this  paragraph
become effective,  Obligor shall send to Holder a certificate  setting forth the
computation of the new Conversion Price.

      Any interest due and owing on the  principal  amount of this Note which is
converted as of the Conversion Date shall be paid on the next succeeding payment
date as though this Note had not been converted.  Interest shall cease to accrue
on the  principal  amount of this Note which is converted  as of the  Conversion
Date.

      No  fractional  shares of Common Stock shall be issued upon  conversion of
this  Note.  Instead  of any  fractional  shares of  Common  Stock  which  would
otherwise be issuable upon conversion of this Note, the Obligor shall pay a cash
adjustment  in respect of such  fraction in an amount equal to the same fraction
multiplied  by the fair market  value per share of the Common Stock at the close
of business on the  Conversion  Date as determined in good faith by the Board of
Directors of the Obligor.

      Unless the shares of Common Stock to be issued on  conversion of this Note
have  been  registered  under  the  Securities  Act of  1933,  as  amended,  the
certificates  representing such shares shall bear a restrictive legend regarding
the  transfer  thereof  in form and  substance  satisfactory  to  counsel to the
Obligor.

      In the  event  that  (a)  Obligor  fails to make  payment  on any date for
payment herein above specified of any principal and/or interest due hereunder on
such date and such failure  continues  for five (5) business  days,  (b) Obligor
admits in writing its  inability to pay its debts as they become due, or makes a
general  assignment for the benefit of creditors or files any petition or action
for relief under any bankruptcy,  reorganization,  insolvency or moratorium law,
or any other law or laws for the  relief of, or  relating  to,  debtors,  (c) an
involuntary   petition  is  filed   against   Obligor   under  any   bankruptcy,
reorganization,  insolvency or moratorium  law, or any other law or laws for the
relief of, or relating to,  debtors  unless such petition  shall be dismissed or
vacated  within  sixty (60) days of the date  hereof or (d) a  monetary  default
occurs under Obligor's credit facility with its secured lenders which default is
not cured, Obligor shall be deemed to be in default hereunder (a "DEFAULT").  In
the event of such Default,  Holder may, at Holder's  option and in Holder's sole
discretion,  ten (10)  business  days after giving notice of Default to Obligor,
accelerate  the maturity of all amounts due under this Note by giving  notice of
such acceleration.

      Obligor  will never be  obligated to pay interest in excess of the Highest
Lawful Rate (as herein  defined),  and, in the event that Holder ever  receives,
collects,  or applies as interest  any such  excess,  such amount which would be
excessive interest will be deemed a partial prepayment of principal and interest
hereunder as such; and if the principal amount of this Note is paid in full, any
remaining  excess will forthwith be paid to Obligor.  In determining  whether or
not the interest paid or payable,  under any specific  contingency,  exceeds the
Highest Lawful Rate,  Obligor and Holder will, to the maximum  extent  permitted
under applicable law: (a) characterize any non-principal  payment as an expense,
fee or premium rather than interest;  (b) exclude  voluntary  prepayment and the
effects thereof; and (c) amortize, prorate, allocate and spread, in equal parts,
or as otherwise  appropriate  to reflect  variations in the Highest Lawful Rate,
the total amount of interest throughout the entire term of this Note so that the


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<PAGE>


interest rate is uniform and does not exceed the Highest Lawful Rate  throughout
the entire term of this Note;  provided that, if this Note is paid and performed
in full  prior  to the end of the  full  contemplated  term  hereof,  and if the
interest  received for the actual period of existence hereof exceeds the Highest
Lawful  Rate,  then  Holder  will refund to Obligor the amount of such excess or
credit the amount of such excess against the principal amount of this Note, and,
in such event,  Holder will not be subject to any penalties provided by any laws
for contracting for, charging, taking, reserving or receiving interest in excess
of the Highest Lawful Rate. As used herein, the term "HIGHEST LAWFUL RATE" means
the maximum  rate of interest  that Holder is allowed to contract  for,  charge,
take,  reserve  or  receive  under the laws of the State of Texas or  applicable
federal law, whichever, from time to time, permits the higher rate.

      Obligor   waives,   presentment,   demand  for   performance,   notice  of
nonperformance,  protest,  notice of protest,  and notice of  dishonor  (but not
notice  of  Default).  No delay on the part of Holder  in  exercising  any right
hereunder  shall operate as a waiver of such right under this Note. This Note is
being delivered in and shall be construed with the laws of the State of Texas.

      The right to plead any and all statutes of limitations as a defense to any
demand on this Note,  or any guaranty  hereof,  or any agreement to the same, or
any  instrument  securing this Note, or any and all  obligations  or liabilities
arising out of or in connection  with this Note, is expressly  waived by Obligor
and each and every endorser or guarantor if any, to the fullest extent permitted
by law.

      The  provisions  of this Note are intended by Obligor to be severable  and
divisible and the invalidity or  unenforceability  of a provision or term herein
shall not invalidate or render  unenforceable  the remainder of this Note or any
part thereof.

      If the  indebtedness  represented  by this  Note or any  part  thereof  is
collected at law or in equity or in bankruptcy,  receivership  or other judicial
proceedings  or if this Note is placed in the hands of attorneys for  collection
after default,  Obligor agrees to pay, in addition to the principal and interest
payable hereon, reasonable attorneys' fees and costs incurred by Holder.

      The Obligor may prepay the unpaid  balance of, and accrued  interest upon,
this  Note in whole or in part at any  time and from  time to time.  In order to
accomplish  such  prepayment,  the Obligor shall provide a written notice to the
Holder  setting  forth (i) the  Obligor's  election  of its right of  prepayment
hereunder and (ii) the date (which shall not be less than five (5) business days
from the date the notice is sent) established by the Obligor for prepayment.  In
the event the Obligor  defaults in making the prepayment,  Holder's rights under
this Note shall continue as though the notice of prepayment had not been sent.

      Any notice or other  communication  (except payment) required or permitted
hereunder  shall be in  writing  and shall be deemed  to have  been  given  upon
delivery if  personally  delivered or one day after  deposit if deposited in the
United States mail for mailing by certified mail, postage prepaid, and addressed
as follows:

      If to Holder:

      If to Obligor:          Crdentia Corp.
                              14114 Dallas Parkway, Suite 600


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<PAGE>


                              Dallas, Texas  75254
                              Attention: James D. Durham

Each of Holder or Obligor  may change his or its  address  for  purposes of this
paragraph by giving to the other party notice in conformance with this paragraph
of such new address.


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<PAGE>


                 SIGNATURE PAGE TO SUBORDINATED PROMISSORY NOTE


EXECUTED as of the Issue Date initially set forth above.

            OBLIGOR:                      CRDENTIA CORP.,
                                          a Delaware corporation

                                          By:_____________________________
                                             Pamela G. Atherton, President



            HOLDER:                       ________________________________


<PAGE>


                 SIGNATURE PAGE TO SUBORDINATED PROMISSORY NOTE


                                 EXHIBIT "A"

                              CONVERSION NOTICE

      The  undersigned  hereby  converts,  in accordance  with the  Subordinated
Promissory  Note dated March 29,  2005 (the  "Note")  $_____________________  in
principal amount of such Note at the Conversion Price set forth therein.  Please
issue a new  note in the form of the Note  for any  remaining  principal  amount
outstanding following the conversion contemplated in this Notice.


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