BUSINESS LEASE

THIS  LEASE,  made  and  entered  into  this  17th  day of  April,  1997,between
Commercial Acquisitions Corporation hereinafter called the "Lessor," and Richard
W. Metcalfe, DDS, PC and Richard W. Metcalfe,  Individual, Jointly and Severally
and as Co-Lessees, hereinafter called the "Lessee;"

         WITHNESSETH THAT:

      1.       Definition of Terms:

              Whenever the words "Lessor" and "Lessee" are used this  indenture,
     they shall include  Lessor and Lessee and shall apply to persons,  both men
     and women, companies, co-partnerships and corporations, and in reading said
     indenture,   the  necessary   grammatical  changes  required  to  make  the
     provisions  hereof  mean and apply as  aforesaid  shall be made in the same
     manner as if written into said indenture.

      2.      Leased Premises:

              In consideration of the payment of the rent hereinafter  provided,
     and the keeping and  performance of each of the covenants and agreements of
     the said  Lessee  hereinafter  set forth,  said  Lessor has and does hereby
     lease unto the said Lessee the following described premises, situate in the
     City of Denver,  County of Denver,  and State of Colorado  to wit:  Lots 16
     through 19;  Block 27; the Park  Avenue  Addition of the City and County of
     Denver, Colorado, aka 1325 East 16th Avenue; Denver, Colorado.

      3.     Term of Lease and Minimum Rent:

              To have and to hold the same  unto the said  Lessee  for a term of
     Ten (10) years  commencing  at 12:00 o'clock noon on the 17th day of April,
     1997 and expiring at 12:00 o'clock noon on the 30th day of April, 2007, for
     the minimum  rental for the full term  aforesaid of the sum of Five hundred
     and forty one thousand nine hundred and fifty ($541,950) Dollars payable in
     monthly  installments of Forty five hundred  ($4,500)  Dollars per month in
     advance on or before 12:00  o'clock noon on the first day of each  calendar
     month  during  the  said  term at the  office  of  Commercial  Acquisitions
     Corporation  in care of P.O. Box 22699  Denver,  CO.  80222-0699 or at such
     other place as the Lessor may designate,  from time to time, in writing.. A
     prorated rent of Twenty one hundred dollars, ($2,100), shall be due for the
     period of 17 April, 1997 through 30 April, 1997.

      4.      Security Deposit:

     None

      5.      Lessee's General Agreement:

              For  and  in   consideration  of  the  leasing  of  said  premises
     aforesaid, the Lessee does covenant and agree as follow, to-wit: To pay the
     rent for said premised  hereinabove provided promptly when due and payable;
     to pay all  assessments  for water rents and sewer charges  levied  against
     said  premises  and all charges for  heating,  cooling  and  lighting  said
     premises;  to pay all  charges  for  telephone  installation;  to keep  all
     improvements upon said premises, including all sewer connections, plumbing,
     heating and cooling appliances,  wiring and glass, in good order and repair
     and to replace  same as the need arises at the expense of said  Lessee;  to
     order no repairs at the expense of the Lessor,  and, at the  expiration  of
     this lease,  to surrender and deliver up said premises in as good order and
     condition  as when the same were  entered  upon,  loss by fire,  inevitable



     accident or ordinary  wear  excepted;  to use said premises for no purposes
     prohibited by the  ordinances of the City of Denver or the County of Denver
     or by the laws of the United States or the State of Colorado,  now in force
     or  hereafter  enacted;   and  for  no  improper  or  questionable  purpose
     whatsoever;  to keep the sidewalks in front and  surrounding  said premises
     free from all litter, dirt, debris,  snow, ice, water and obstructions;  to
     keep said  premises  clean and in the  sanitary  condition  required by the
     ordinances and the health,  sanitary and police  regulations of the City of
     Denver and/or County of Denver, or any other political  subdivision  having
     jurisdiction  over same;  to keep the interior of the premises  such as the
     windows,  floors,  walls,  doors,  showcases and fixtures clean and neat in
     appearance;  to remove all trash and debris which may be found in or around
     the leased premises;  to neither permit nor suffer any disorderly  conduct,
     noise or nuisance about said premises having a tendency to annoy or disturb
     any  persons  occupying  adjacent  premises,  and to commit no waste on the
     leased premises; to neither permit nor suffer said premises, or the wall or
     floors thereof,  to be endangered by  overloading;  to permit the Lessor to
     place a For Rent card upon said  premises at any time sixty (60) day before
     the end of this lease;  to surrender and deliver up the  possession of said
     premises  promptly  at the  expiration  of  this  lease,  or,  in  case  of
     termination of this lease on account of breach in the keeping of any one or
     more of the covenants or agreements hereof, upon three (3) days' notice.

      6.      Failure to Tenant to Maintain Premises:

              If Lessee  refuses or neglects to repair or maintain the premises,
     as required hereunder,  to the reasonable satisfaction of Lessor as soon as
     reasonably  possible  after  written  demand,  Lessor may make such repairs
     without  liability  to  Lessee  for any loss or damage  that may  accrue to
     Lessee's  merchandise,  fixtures or other property, or to Lessee's business
     by reason thereof,  and upon completion thereof,  Lessee shall pay Lessor's
     cost for making such repairs up presentation of a bill therefor.

      7.      Indemnity Agreements:

              Lessee  agrees to  neither  hold nor  attempt  to hold the  Lessor
     liable for any  injury or damage,  either  proximate  or remote,  occurring
     through or caused by any  repairs,  alterations,  injury or accident to the
     above described premises,  to adjacent premises or other parts of the above
     premises not herein  demised,  or by reason of the negligence or default of
     the owners or occupants thereof, or any person, or liable for any injury or
     damage occasioned by defective electric wiring, or the breaking,  bursting,
     stoppage or leaking  resulting from freezing or otherwise hold harmless the
     Lessor  from all loss,  expense,  damage or injury to persons  or  property
     arising from or occurring by reason of its  occupation or use of the leased
     premises, save and except only such losses or injuries arising or occurring
     by any act or omission of the  Lessor.  The Lessor  shall not be liable for
     any damage to  property  of the  Lessee or of others  located on the leased
     premises,  nor for the loss of or  damage to any  property  of Lessee or of
     others by theft or otherwise.  All property of Lessee kept or stored on the
     leased  premises shall be so kept or stored at the risk of Lessee only, and
     Lessee shall hold Lessor  harmless from any claims arising out of damage to
     the same.

      8.      Repairs to the Premises:

              Lessee  agrees  that all repairs to the  structural  walls and the
     roof of said leased premises shall be its obligation, Lessee shall have the
     duty or  obligation  to  repair  any  damage  caused  by the  Lessee or the
     Lessee's employees.  Lessee shall notify Lessor, in writing, of any repairs
     or maintenance to said  structural  walls or of which may be required,  and
     Lessee shall have a reasonable  time to make such  repairs.  Lessee  agrees
     that all other repairs to and  maintenance of said premises,  including but
     not limited to interior  walls,  doors,  glass and  blacktop,  shall be the
     obligation and responsibility of the Lessee.



      9.      Right of Entry, Changes and Additions to Building:

              Lessor hereby expressly reserves the right, during normal business
     hours,  to enter onto the leased  premises  for the purpose of  inspection,
     repairs, alterations,  improvements and additions to the leased premises or
     the  building of which it is a part;  Lessor also  expressly  reserves  the
     right to add  extensions or alterations  to the existing  building.  Lessee
     shall  not,  however,  contract  for or make  any  alterations,  additions,
     extensions  or  construction  of any kind to the  leased  premises,  unless
     expressly approved by the Lessor in writing.

      10.     Character of Occupancy:

              The leased  premises  shall be used and  occupied  only as Dental,
Medical or General Offices.

              Insurance:

              The Lessee further agrees to provide  public  liability  insurance
     with  bodily  injury  limits  of not  less  than  $250,000.00  per  person,
     $500,000.00 per occurrence and property damage insurance with limits of not
     less than  $250,000.00 per occurrence,  $500,000.00 per aggregate,  written
     with a company  having a Best's key rating of A+ 4A+ and shall name  Lessor
     or its assigns under said insurance  policy as additional  insured.  Lessee
     shall furnish to Lessor a  certificate  of insurance  indicating  that said
     policy is in full  force  and  effect,  that  Lessor  has been  named as an
     additional  insured and that said  policy  will not be canceled  unless ten
     (10) days' prior written notice of the proposed cancellation has been given
     to Lessor.  Further,  Lessee agrees to provide building  insurance not less
     than  $425,000  in the event of any  building  loss;  Loss Payee  should be
     proated to such amounts as any first  mortgage  lender and their  interests
     may, from time to time, appear;  and, the balance to and for the benefit of
     Commercial Acquisitions Corporation.

              Signs:

              No  signs or  advertisement  shall  be placed or printed  upon the
     outer walls,  doors,  windows,  roof or land area of the demised  premises,
     except those signs and  locations  as the Lessor  shall  approve in writing
     prior to  installation.  Those  currently  in  place,  as of the 6th day of
     April, 1997, are approved by execution of this lease.

              Replacement of Building:

              In the event the  demised  premised  or a  portion  thereof  shall
     become  untenantable  on  account of damage by fire,  act of God,  or other
     casualty,  Lessor  shall be given the option to correct the  efficiency  or
     condition  which shall  render the premises  untenantable.  Within ten (10)
     days  after  receipt  of written  notice  from  Lessee as the damage to the
     property,  Lessor  shall  notify  Lessee in writing as to whether or not it
     elects to repair  the same.  If, in the  opinion of the  Lessor,  it is not
     feasible to repair or rebuild the same, then, and in that event, the Lessor
     shall have the right to terminate this lease. In the event Lessor elects to
     repair said  premises it shall have one hundred (100) days from the date of
     its  notice to Lessee  to effect  such  repairs.  During  the  period  from
     Lessor's  receipt of notice from  Lessee of damage to the demised  premises
     until said premises are restored to their prior  condition  and  possession
     thereof  given to  Lessee,  the rent shall  abate  upon the  portion of the
     premises  that  is  untenantable,   except  that  if  the  premises  become
     untenantable  due to the actions of the Lessee or its agents or  employees,
     the rent  shall  continue  in full  force and  effect  and shall not abate.
     Lessor  shall not in any case be liable  for any loss of  profits or income
     occasioned to Lessee  during such period.  In the event said repair has not
     been completed within the period specified, then Lessee may have the option





     to cancel the lease.  If either  the Lessor or the Lessee  terminates  this
     lease as above provided in this paragraph,  any monies due and owing to the
     Lessor at that  date  shall be paid by the  Lessee to the date that  Lessee
     vacates  said  premises,  and all further  obligations  on the part of both
     parties hereto shall cease and Lessor shall incur no obligation  whatsoever
     from the termination of said lease.

              Holdover Agreement:

              If, after the  expiration of the term of this lease,  Lessee shall
     remain in  possession  of the  demised  premises  and  continue to pay rent
     without any express  written  agreement as to such holding over,  then such
     holding  over shall be deemed and taken to be a holding over upon a tenancy
     from month to month at a monthly  rental  equivalent to the maximum  rental
     most recently charged,  such payments to be made as hereinbefore  provided.
     In the event of such holding over, all the terms of the lease as herein set
     out are to remain in full force and effect on said month to month basis.

              Bankruptcy:

     It is further  agreed  between the parties hereto that, if the Lessee shall
     be declared  insolvent or bankrupt,  or if any  assignment  of the Lessee's
     property shall be made for the benefit of the creditors or otherwise, or if
     the  Lessee's   leasehold  interest  herein  shall  be  levied  upon  under
     execution.,  or seized by virtue of any wit of any court of law, or trustee
     in  bankruptcy,  or a receiver by appointed for the property of the Lessee,
     whether under  operation of the state or the federal  statues,  then and in
     any such case, the Lessor may, at its option, immediately,  with or without
     notice (notice being expressly waived), terminate this lease an immediately
     take possession of said premises without the same working and forfeiture of
     the obligations of the Lessee hereunder.

              Subordination:

              Lessee  agrees  that this  lease is and  shall  be, at all  times,
     subject and  subordinate  to the lien of any mortgages  which Lessor or its
     assigns shall make covering said premises and to any and all advances to be
     made  thereunder  and to the interest  thereon;  provided,  however,  that,
     regardless of any default under any mortgages or any  possession or sale of
     said  premises  under  such  mortgages,  so long  as  Lessee  performs  all
     covenants  and  conditions  of this  lease  and  continues  to pay  rent to
     whomsoever  may be  lawfully  entitled  to same,  this  lease and  Lessee's
     possession  thereunder  shall no be  disturbed  by the  mortgagee or anyone
     claiming under or through such mortgages.  Lessee agrees to execute any and
     all  instruments  in writing which may be required by Lessor to subordinate
     Lessee  rights  to lien of such  mortgages,  subject  to the  terms of this
     paragraph.

              Financial Statements:

              Within  ten (10)  days  after  written  request  has been  made by
     Lessor,  Lessee (and the  guarantor,  if any) shall provide the Lessor with
     the most  recent  financial  statements  as  required  by the Lessor in its
     course of business  dealing on the  property of which the demised  premises
     are a part.  The  submittal of Financial  Statements  shall be requested no
     more frequently than annually and shall be in  substantively  the same form
     as was submitted by the Lessee to the Lessor with this lease.

              Default of Tenant:

              The Lessee  further  covenants  and agrees that, if the rent above
     reserved, or any part thereof, shall be in default, or in case of breach of
     any of the  covenants or agreements  herein,  Lessor may declare this lease
     terminated,  and after the  expiration  of 10,  (Ten) days from the date of




     receipt of service of written  notice to that  effect,  be  entitled to the
     possession of said  premises,  either by the expiration of this lease or by
     any  termination  of said term as herein  provided for. If the Lessee shall
     refuse to surrender and deliver up the possession of said premises,  or any
     part thereof,  and take possession thereof and repossess the same as of the
     Lessor's  former  estate,  and expel,  remove and put out of possession the
     Lessee, using such help, assistance and force in so doing as may be needful
     and proper,  without being liable for prosecution or damages therefor,  and
     without  prejudice  to any remedy  allowed by law  available in such cases.
     This paragraph shall be supplemental to paragraph 4-(b).

              Vacating During Term:

              If the Lessee shall abandon or vacate the leased  premised  before
     the end of the  term of this  lease,  or  shall  suffer  the  rent to be in
     arrears,  the  Lessor  may at its  option  and  without  notice  enter said
     premises,  remove any signs and property of the Lessee therefrom, and relet
     the  leased  premises  or any part  hereof as it may see fit  without  such
     retaking,  voiding or termination  this lease, and for the purposes of such
     reletting, the Lessor is authorized to make any repairs or changes in or to
     the leased  premises,  at the expense of the Lessee (which shall be payable
     to the Lessor  upon  demand),  as may be  necessary  or  desirable  for the
     purpose of such  reletting,  and if a sum shall not be  realized  from such
     reletting to equal the monthly rental reserved and stipulated  herein to be
     paid by the  Lessee,  the Lessee will pay such  deficiency  each month upon
     demand  therefor,  and if suit is filed to collect  any monies due from the
     Lessee under this lease,  reasonable  attorney's  fees shall be assessed as
     part of the judgments.


              Assignment and Subletting:

              Lessee  shall not  assign or  mortgage  this  lease in whole or in
     part, nor sublet all or any part of the leased  premises  without the prior
     written consent of the Lessor, and Lessor agrees that such consent will not
     be  unreasonable  withheld.  In the event the leased premises are sublet by
     the Lessee, or this lease is assigned or mortgaged,  the Lessee will remain
     solely  liable under the terms of this lease and shall not be released from
     the  performance of any of the terms,  covenants and  conditions  contained
     herein.  Provided  that there shall have been a sale of the business of the
     tenant,  (Dr.  Richard W.  Metcalfe,  DDS,  PC), such  assignment  shall be
     permitted if (a) The credit  worthiness of the new Lessee shall be equal to
     or greater than the current credit  worthiness of the existing Lessee;  or,
     (b) The current Lessee shall remain a guarantor for any and all obligations
     of the new Lessee under the terms of this Lease.  If (b) shall  apply,  the
     Lessor  agrees to review  the credit  worthiness  of the new Lessee no more
     frequently  than annually and on the annual  anniversary  date of the Lease
     and the  existing  Lessee  shall have the right to  request  release of its
     guaranty,  but the Lessor shall have no  obligation to do so in whole or in
     part until such time as the credit  worthiness  of the new Lessee  shall be
     equal to or greater  than the current  credit  worthiness  of the  existing
     Lessee.  Further,  the terms and conditions of the existing sub-lease shall
     be (a)  Disclosed  to the Lessor;  and,  (b)  Assigned by this Lease to the
     Lessor as  additional  collateral  with the  Lessors  acknowledgment  that,
     absent any default by the Lessee, any rental income derived therefrom shall
     be the property of the Lessee.  And, any sublease of any space unused as of
     this  date is  subject  to the  written  approval  of the  Lessor  and said
     approval  shall  not  be  unreasonably  withheld.  Further,  Lessor  hereby
     approves of the existing  sublease by and between the Lessee and Dr. Daniel
     W. Ray, DMD, MS and Lessee  hereby  assigns said lease to the Lessor in the
     event of any uncured  default of the Lessee  and,  with  execution  of this
     lease shall  provide the Lessor with  written  disclosure  of the terms and
     conditions of said sublease.




              Lien of Lessor:

              None

              Surrender of Possession:

              Lessee agrees to deliver up and surrender to Lessor  possession of
     the leased premises,  including all plumbing,  wiring,  sewer  connections,
     lighting  fixtures,   glass,  fixtures,   walls,   ceilings,   floors,  and
     appurtenances  at the  expiration  or  termination  of  this  lease  or any
     extension  hereof,  by lapse of time or  otherwise,  in as good  order  and
     condition  as when  possession  was  taken by the  Lessee,  excepting  only
     ordinary  wear and tear or damage by the  elements  (occurring  without the
     fault of the Lessee or other  persons  permitted by the Lessee to occupy or
     enter the leased  premises,  or any part  thereof)  or by act of God, or by
     insurrection, riot, invasion or commotion, or of military or usurped power.
     If the Lessee  shall fail to remove any effects  which they are entitled to
     remove  from said  premises  upon the  termination  of this  lease,  or any
     extension hereof, for any cause whatsoever,  the Lessor, at its option, may
     remove the same and store or dispose of the said effects, without liability
     for loss or damage  thereto,  and Lessee  agrees to pay to Lessor on demand
     any and all  expenses  incurred  in such  removal,  including  the  cost of
     removal of signs from the windows, making the premises including sidewalks,
     courts or alleyway  adjacent thereto,  if any, free from all dirt,  litter,
     debris and obstruction, including court costs, attorney's fees, storage and
     insurance  charges on such effects for any length of time the same shall be
     in the Lessor's possession;  or the Lessor, at its option,  without notice,
     may sell such effects, or any of the, at private or public sale and without
     legal process,  for such price or  consideration  as the Lessor may obtain,
     and apply the  proceeds  of such sale upon any amounts due under this lease
     from the  Lessee to the  Lessor,  and upon the  expense  incidental  to the
     removing,  cleaning the  premises,  sell said effects,  an other  expenses,
     rendering the surplus,  if any, to the Lessee;  provided,  however,  in the
     event the process of such sale or sales are  insufficient  to reimburse the
     Lessor, Lessee shall pay such deficiency upon demand.

              Legal Costs and Expenses:

              Lessee agrees to pay Lessor for all costs and expenses,  including
     a  reasonable  attorney's  fee,  in any court  action  brought by Lessor to
     recover any rent due and unpaid under the terms  hereof,  or for the breach
     of any  of  the  terms  and  conditions  herein  contained,  or to  recover
     possession  of the leased  premises,  whether  or not such court  action or
     actions shall proceed to judgment.

              Notices:

              All  notices,  demands, request  or other  instruments required in
     this lease to be given by Lessee to Lessor  shall be sent by  certified  or
     registered mail to Lessor at P.O. Box 22699;  Denver,  Colorado 80222-0699.
     All notices,  demands, requests or other instruments required in this lease
     to be given by Lessor to Lessee shall be sent certified or registered  mail
     to Lessee at 1325 E. 16th Avenue; Denver, Colorado 80218.

              Mechanic's Lien:

              The right of  the Lessee, or any person  claiming through or under
     Lessee, to charge any mechanic or materialman's liens for labor or material
     upon or  against  Lessor's  interest  in the  demised  premises  is  hereby
     expressly denied.



              Condemnation of Leased Premises:

              If the entire  demised  premises,  at any time  during the term of
     this lease or any  extension  thereof,  shall be taken by the exercise of a
     power of eminent domain,  this lease shall then terminate as of the date of
     title  vesting in such  proceeding,  all  rentals  shall be paid up to that
     date,  and Lessee  shall have no claim  against  Lessor nor the  condemning
     authority for the value of the unexpired term of this lease.

              In the event of a partial  taking of the building or more than 25%
     of the land area, which leaves the premises unfit for the normal and proper
     conduct of the business of the Lessee, then the lessee shall have the right
     to cancel and  terminate  this  lease  effective  upon the  actual  partial
     taking, all rentals shall be paid up to that date, and Lessee shall have no
     claim  against  Lessor nor the  condemning  authority  for the value of any
     unexpired term of this lease.  If this lease shall not be canceled as above
     provided,  it shall  continue in effect and the rental  after such  partial
     taking shall be that part of the rental  herein agreed to be paid which the
     value of the untaken part of the  premises,  immediately  after the taking,
     bears to the value of the entire demised  premised  immediately  before the
     taking. If the lessee's continued use of the premises requires  alterations
     and  repairs  by  reason  of a  partial  taking,  the  Lessor  may elect to
     terminate  this lease within thirty (30) days after the actual  taking;  or
     subject to Lessee's  right of  termination  above  provided,  which must be
     exercised in writing within thirty (30) days after such partial taking ,may
     elect to continue  it, in which event the Lessor  shall make all  necessary
     alterations  and repairs at its expense which are required  because of such
     partial  taking.  Until  such  alterations  and  repairs  shall  have  been
     completed,  and equitable abatement of rent shall be made to Lessee for any
     portion  of the  premises  unfit for  occupancy  and use in the  conduct of
     Lessee's  business  for the period  during which the same is unfit for such
     occupancy and use.

              In the event of any  condemnation or taking as aforesaid,  whether
     whole or  partial,  Lessee  shall not be  entitled to any part of the award
     paid for said  condemnation;  Lessor is to receive  the full amount of such
     award,  Lessee  hereby  expressly  waiving  any  right or claim to any part
     thereof. Although all such damages awarded in the event of any condemnation
     are  to  belong  to  the  Lessor,  whether  such  damages  are  awarded  as
     compensation  for  diminution  value of the  leasehold or to the fee of the
     leased premises,  Lessee shall have the right to claim and recover from the
     condemning authority,  but not from the Lessor, such compensation as may be
     separately  awarded  or  recoverable  by  Lessee in  Lessee's  own right on
     account  of any and all  damage  to  Lessee's  business  by  reason  of the
     condemnation  and for or on  account  of any cost or loss to  which  Lessee
     might  be  put  in  removing  Lessee's  merchandise,  furniture,  fixtures,
     leasehold improvements and equipment.

              Waiver:

              The  waiver  by Lessor of any  breach  of any  term,  covenant  or
     condition herein contained shall not be deemed to be a waiver of such term,
     covenant or  condition  on any  subsequent  breach of the same or any other
     term, covenant or condition herein contained.  The subsequent acceptance or
     rent  hereunder  by  Lessor  shall  not be  deemed  to be a  waiver  of any
     preceding breach by Lessee of any term covenant or condition of the time of
     the  acceptance of such rent. No covenant,  term or condition of this lease
     shall be deemed to have been waived by the Lessor, unless such waiver be in
     writing duly executed by the Lessor.




              Taxes and Fire and Hazard Insurance:

              (a) Lessee shall have the option of (1) Paying the property  taxes
     when  due  and  providing  the  Lessor  with  written  evidence  in a  form
     satisfactory  to the  Lessor  that  said  taxes  have been paid in a timely
     manner;  or (2)  Paying  the Lessor  1/12th of the taxes  estimated  by the
     Lessor to become due in any subsequent year with each monthly payment. This
     option  must be elected on the 1st day of January of any year in writing by
     the Lessee and by notice to the Lessor.  If the Lessee shall fail to comply
     with this provision and the Lessor shall advance any sum for the payment of
     said taxation, this shall (i) Constitute a default of the Lessee; and, (ii)
     Any funds advanced by the Lessor for said  purposes,  or for any other bona
     fide obligation of the Lessee hereunder,  shall accrue interest at the rate
     of Eighteen percent, (18%), per annum with said interest due and payable by
     the Lessee.

              (b)  Lessee  shall  insure  the  property  for fire  and  extended
     coverage in the amount of Four  hundred and twenty five  thousand  dollars,
     ($425,000),  as defined herein,  i.e. form and terms of coverage,  and with
     such annual  increases in value as may be  determined by the greater of (1)
     The Metro Denver Consumer Price Index;  or, (2) An appraisal by a bona fide
     real estate broker or appraiser with the cost of such appraisal born by the
     Lessor.

              (c) Upon the expiration of the existing coverage,  which must meet
     the terms and conditions  defined herein,  i.e. form and terms of coverage,
     the Lessor may seek quotes for comparable  coverage and, if said quotes are
     comparable  as to cost and coverage and insurer,  the policy may be changed
     at the sole  discretion of the Lessee.  The costs, if any, for seeking said
     quotes  shall be (1) At the sole costs and expense of the  Lessor;  (2) The
     Lessor shall have no  obligation  to seek such quotes;  and, (3) The Lessee
     may seek such  quotes  at its sole  cost and  expense  and  submit  same in
     writing for approval by the Lessor.

              Costs of All Building Areas; Components; Grounds and Facilities

              In addition to the rental  payable  pursuant to paragraph 3 hereof
     and in any other provision of this Lease,  the Lessee shall pay any and all
     costs of operating  and  maintaining  all areas,  building  components - in
     whole or in part - grounds and facilities, including without limitation all
     parking areas,  access roads,  sidewalks,  landscaped space and other space
     used in or  available  to the  building  and  property as defined  herein..
     Operating and maintaining  such areas and facilities  shall include without
     limitation  furnishing exterior and parking area lighting,  cleaning,  snow
     removal, line painting,  care of grass, shrubs and plants, payment of water
     and sewerage  charges and general  maintenance  of all areas and facilities
     used in or available to the  building and property as defined  herein.  The
     repair  or  replacement  of any  portion  of the  building  or the  parking
     facilities  appurtenant  thereto  shall be included in such  operation  and
     maintenance.

              Additional Provisions:

              The base or  minimum  rental as  defined  herein  shall be in full
     force and effect for the first  Five,  (5),  year  period of the lease term
     plus the prorated period of 17 through 30 April, 1997. Thereafter, the base
     or minimum monthly rental shall increase on the annual  anniversary date of
     the lease, by not less than 3.50%,  (Three and 50/100's  percent) per annum
     and no  greater  than  5.50%,  (Five and  50/100's  percent),  per annum as
     determined by the Metro Denver Consumer Price Index, (CPI), as is available
     from the Bureau of Labor  Statistics or such other bona fide source of like
     information. Further, this increase shall be in full force and effect as of
     the annual  anniversary date of the Lease and the prevailing CPI, i.e. that
     which  shall  have been in effect  the  January  1st  preceding  the annual




     anniversary  date of the lease.  Any subsequent or holdover period shall be
     increased by 5.5%, (Five and 50/100's percent), per annum as defined herein
     unless there shall have been other terms agreed to in writing by the Lessor
     and further,  the Lessor is not  obligated to any increase in lease term by
     this agreement.

              Successors and Assigns:

              The  obligations and rights under this lease shall be binding upon
     and  inure  to  the  benefit  of  the  heirs,  administrators,   executors,
     successors  and  assigns  of  the  parties;  provided,  however,  that  any
     assignment  or  subletting  by the Lessee in violation of the terms of this
     lease shall not vest any rights whatsoever in the assignee or subtenant.

              IN WITNESS WHEREOF, this lease is hereby executed the day and year
first above written.

ATTEST:                              Lessor: Commercial Acquisitions Corporation
       ----------------------------          -----------------------------------
       Secretary
                                      By: /s/ David J. Clamage
                                          --------------------------------------

                                      Title: Chairman
                                             -----------------------------------


ATTEST: Kenneth R. Shwayder           Lessee:  /s/ Richard Metcalfe
       ----------------------------          -----------------------------------
       Secretary
                                      By:  Richard W. Metcalfe, DDS, PC
                                          --------------------------------------

                                      Title:
                                             -----------------------------------





STATE OF COLORADO        )
                         ) ss
COUNTY OF ARAPAHOE       )

          The foregoing Business Lease was acknowledged  before me this 16th day
of April, 1997, by Richard W. Metcalfe, individually and on behalf of Richard W.
Metcalfe, DDS, PC.

          Witness my hand and official seal.

S E A L
My Commission expires July 31, 1999

                                             /s/ Shirley Hendren
                                             -----------------------------------
                                             Notary Public

STATE OF COLORADO        )
                         ) ss
COUNTY OF ARAPAHOE       )

          The foregoing Business Lease was acknowledged  before me this 17th day
of April,  1997,  by David J.  Clamage as  Chairman of  Commercial  Acquisitions
Corporation.

          Witness my hand and official seal.

S E A L
My Commission expires July 31, 1999
                                             /s/ Shirley Hendren
                                             -----------------------------------
                                             Notary Public