﻿<?xml version="1.0" encoding="utf-8"?>
<Return xmlns="http://www.irs.gov/efile" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.irs.gov/efile" returnVersion="2011v1.5">
  <ReturnHeader binaryAttachmentCount="0">
    <Timestamp>2013-03-07T13:54:20-06:00</Timestamp>
    <TaxPeriodEndDate>2012-04-30</TaxPeriodEndDate>
    <PreparerFirm>
      <EIN>042571780</EIN>
      <PreparerFirmBusinessName>
        <BusinessNameLine1>ALEXANDER ARONSON FINNING &amp; CO PC</BusinessNameLine1>
      </PreparerFirmBusinessName>
      <PreparerFirmUSAddress>
        <AddressLine1>21 EAST MAIN STREET</AddressLine1>
        <City>WESTBORO</City>
        <State>MA</State>
        <ZIPCode>01581</ZIPCode>
      </PreparerFirmUSAddress>
    </PreparerFirm>
    <ReturnType>990</ReturnType>
    <TaxPeriodBeginDate>2011-05-01</TaxPeriodBeginDate>
    <Filer>
      <EIN>041590155</EIN>
      <Name>
        <BusinessNameLine1>MASSACHUSETTS DENTAL SOCIETY</BusinessNameLine1>
      </Name>
      <NameControl>MASS</NameControl>
      <Phone>5084809797</Phone>
      <USAddress>
        <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
        <City>SOUTHBOROUGH</City>
        <State>MA</State>
        <ZIPCode>01745</ZIPCode>
      </USAddress>
    </Filer>
    <Officer>
      <Name>KATHLEEN BOYCE</Name>
      <Title>CFO</Title>
      <Phone>5084809747</Phone>
      <DateSigned>2013-03-07</DateSigned>
      <AuthorizeThirdParty>1</AuthorizeThirdParty>
    </Officer>
    <Preparer>
      <Name>JOHN BUCKLEY CPA</Name>
      <PTIN>P00830631</PTIN>
      <Phone>5083669100</Phone>
      <DatePrepared>2013-03-07</DatePrepared>
    </Preparer>
    <TaxYear>2011</TaxYear>
    <BuildTS>2016-03-07 17:11:31Z</BuildTS>
  </ReturnHeader>
  <ReturnData documentCount="7">
    <IRS990 documentId="RetDoc1038000001" referenceDocumentId="RetDoc1044400001">
      <NameOfPrincipalOfficerPerson>KATHLEEN BOYCE</NameOfPrincipalOfficerPerson>
      <AddressPrincipalOfficerUS>
        <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
        <City>SOUTHBOROUGH</City>
        <State>MA</State>
        <ZIPCode>01745</ZIPCode>
      </AddressPrincipalOfficerUS>
      <GrossReceipts>16334165</GrossReceipts>
      <GroupReturnForAffiliates>0</GroupReturnForAffiliates>
      <Organization501c typeOf501cOrganization="6">X</Organization501c>
      <WebSite>WWW.MASSDENTAL.ORG</WebSite>
      <TypeOfOrganizationCorporation>X</TypeOfOrganizationCorporation>
      <YearFormation>1865</YearFormation>
      <StateLegalDomicile>MA</StateLegalDomicile>
      <ActivityOrMissionDescription>TO PROMOTE AND ADVANCE THE ART AND SCIENCE OF DENTISTRY AND THE INTEREST OF THE MEMBER DENTISTRY RELATIVE TO THE PRACTICE OF DENTISTRY AND TO REPRESENT MEMBERS IN RELATIONSHIPS WITH THIRD PARTIES AND WITH AGENCIES OF FEDERAL, STATE AND LOCAL GOVERNMENT.</ActivityOrMissionDescription>
      <NbrVotingMembersGoverningBody>22</NbrVotingMembersGoverningBody>
      <NbrIndependentVotingMembers>22</NbrIndependentVotingMembers>
      <TotalNbrEmployees>47</TotalNbrEmployees>
      <TotalNbrVolunteers>550</TotalNbrVolunteers>
      <TotalGrossUBI>-31075</TotalGrossUBI>
      <NetUnrelatedBusinessTxblIncome>-94891</NetUnrelatedBusinessTxblIncome>
      <ContributionsGrantsPriorYear>32050</ContributionsGrantsPriorYear>
      <ContributionsGrantsCurrentYear>38075</ContributionsGrantsCurrentYear>
      <ProgramServiceRevenuePriorYear>9488062</ProgramServiceRevenuePriorYear>
      <ProgramServiceRevenueCY>9379372</ProgramServiceRevenueCY>
      <InvestmentIncomePriorYear>372091</InvestmentIncomePriorYear>
      <InvestmentIncomeCurrentYear>360018</InvestmentIncomeCurrentYear>
      <OtherRevenuePriorYear>404946</OtherRevenuePriorYear>
      <OtherRevenueCurrentYear>79058</OtherRevenueCurrentYear>
      <TotalRevenuePriorYear>10297149</TotalRevenuePriorYear>
      <TotalRevenueCurrentYear>9856523</TotalRevenueCurrentYear>
      <GrantsAndSimilarAmntsPriorYear>77375</GrantsAndSimilarAmntsPriorYear>
      <GrantsAndSimilarAmntsCY>75279</GrantsAndSimilarAmntsCY>
      <BenefitsPaidToMembersPriorYear>0</BenefitsPaidToMembersPriorYear>
      <BenefitsPaidToMembersCY>0</BenefitsPaidToMembersCY>
      <SalariesEtcPriorYear>3327255</SalariesEtcPriorYear>
      <SalariesEtcCurrentYear>3411004</SalariesEtcCurrentYear>
      <TotalProfFundrsngExpPriorYear>0</TotalProfFundrsngExpPriorYear>
      <TotalProfFundrsngExpCY>0</TotalProfFundrsngExpCY>
      <TotalFundrsngExpCurrentYear>0</TotalFundrsngExpCurrentYear>
      <OtherExpensePriorYear>6128638</OtherExpensePriorYear>
      <OtherExpensesCurrentYear>6111471</OtherExpensesCurrentYear>
      <TotalExpensesPriorYear>9533268</TotalExpensesPriorYear>
      <TotalExpensesCurrentYear>9597754</TotalExpensesCurrentYear>
      <RevenuesLessExpensesPriorYear>763881</RevenuesLessExpensesPriorYear>
      <RevenuesLessExpensesCY>258769</RevenuesLessExpensesCY>
      <TotalAssetsBOY>16220286</TotalAssetsBOY>
      <TotalAssetsEOY>15232877</TotalAssetsEOY>
      <TotalLiabilitiesBOY>8450925</TotalLiabilitiesBOY>
      <TotalLiabilitiesEOY>7581733</TotalLiabilitiesEOY>
      <NetAssetsOrFundBalancesBOY>7769361</NetAssetsOrFundBalancesBOY>
      <NetAssetsOrFundBalancesEOY>7651144</NetAssetsOrFundBalancesEOY>
      <MissionDescription>TO PROMOTE AND ADVANCE THE ART AND SCIENCE OF DENTISTRY AND THE INTEREST OF THE MEMBER DENTISTRY RELATIVE TO THE PRACTICE OF DENTISTRY AND TO REPRESENT MEMBERS IN RELATIONSHIPS WITH THIRD PARTIES AND WITH AGENCIES OF FEDERAL, STATE AND LOCAL GOVERNMENT.</MissionDescription>
      <SignificantNewProgramServices>0</SignificantNewProgramServices>
      <SignificantChange>0</SignificantChange>
      <Description>TO PROMOTE AND ADVANCE THE ART AND SCIENCE OF DENTISTRY AND THE INTEREST OF THE MEMBER DETDISTRY RELATIVE TO THE PRACTICE OF DENTISTRY AND TO REPRESENT MEMBERS IN RELATIONSHIPS WITH THIRD PARTIES AND WITH AGENCIES OF FEDERAL, STATE AND LOCAL GOVERNMENT.</Description>
      <DescribedIn501C3>0</DescribedIn501C3>
      <ScheduleBRequired>0</ScheduleBRequired>
      <PoliticalActivities referenceDocumentId="RetDoc1039700001">0</PoliticalActivities>
      <SubjectToProxyTax referenceDocumentId="RetDoc1039700001">1</SubjectToProxyTax>
      <DonorAdvisedFunds referenceDocumentId="RetDoc1040000001">0</DonorAdvisedFunds>
      <ConservationEasements referenceDocumentId="RetDoc1040000001">0</ConservationEasements>
      <CollectionsOfArt referenceDocumentId="RetDoc1040000001">0</CollectionsOfArt>
      <CreditCounseling referenceDocumentId="RetDoc1040000001">0</CreditCounseling>
      <TermOrPermanentEndowments referenceDocumentId="RetDoc1040000001">0</TermOrPermanentEndowments>
      <ReportLandBldgEquip referenceDocumentId="RetDoc1040000001">1</ReportLandBldgEquip>
      <ReportInvestOthSecurities referenceDocumentId="RetDoc1040000001">0</ReportInvestOthSecurities>
      <ReportProgRelInvest referenceDocumentId="RetDoc1040000001">0</ReportProgRelInvest>
      <ReportOtherAssets referenceDocumentId="RetDoc1040000001">0</ReportOtherAssets>
      <ReportOtherLiabilities referenceDocumentId="RetDoc1040000001">1</ReportOtherLiabilities>
      <ReportFin48Footnote referenceDocumentId="RetDoc1040000001">1</ReportFin48Footnote>
      <IndependentAuditFinancialStmt referenceDocumentId="RetDoc1040000001">0</IndependentAuditFinancialStmt>
      <ConsolidatedAuditFinancialStmt referenceDocumentId="RetDoc1040000001">1</ConsolidatedAuditFinancialStmt>
      <School>0</School>
      <ForeignOffice>0</ForeignOffice>
      <ForeignActivities>0</ForeignActivities>
      <MoreThan5000KToOrganizations>0</MoreThan5000KToOrganizations>
      <MoreThan5000KToIndividuals>0</MoreThan5000KToIndividuals>
      <ProfessionalFundraising>0</ProfessionalFundraising>
      <FundraisingActivities>0</FundraisingActivities>
      <Gaming>0</Gaming>
      <Hospital>0</Hospital>
      <GrantsToOrganizations referenceDocumentId="RetDoc1041900001">1</GrantsToOrganizations>
      <GrantsToIndividuals referenceDocumentId="RetDoc1041900001">1</GrantsToIndividuals>
      <ScheduleJRequired referenceDocumentId="RetDoc1042400001">1</ScheduleJRequired>
      <TaxExemptBonds>0</TaxExemptBonds>
      <LoanToOfficerOrDQP>0</LoanToOfficerOrDQP>
      <GrantToRelatedPerson>0</GrantToRelatedPerson>
      <BsnssRltnshpWithOrganization>0</BsnssRltnshpWithOrganization>
      <BsnssRltnshpThruFamilyMember>0</BsnssRltnshpThruFamilyMember>
      <OfficerEntityWithBsnssRltnshp>0</OfficerEntityWithBsnssRltnshp>
      <DeductibleNonCashContributions>0</DeductibleNonCashContributions>
      <DeductibleContributionsOfArt>0</DeductibleContributionsOfArt>
      <Terminated>0</Terminated>
      <PartialLiquidation>0</PartialLiquidation>
      <DisregardedEntity referenceDocumentId="RetDoc1043400001">1</DisregardedEntity>
      <RelatedEntity referenceDocumentId="RetDoc1043400001">1</RelatedEntity>
      <RelatedOrgControlledEntity>0</RelatedOrgControlledEntity>
      <TransactionRelatedEntity referenceDocumentId="RetDoc1043400001">0</TransactionRelatedEntity>
      <ActivitiesConductedPartnership referenceDocumentId="RetDoc1043400001">0</ActivitiesConductedPartnership>
      <ScheduleORequired>1</ScheduleORequired>
      <NumberFormsTransmittedWith1096>132</NumberFormsTransmittedWith1096>
      <NumberW2GIncluded>0</NumberW2GIncluded>
      <NumberOfEmployees>47</NumberOfEmployees>
      <EmploymentTaxReturnsFiled>1</EmploymentTaxReturnsFiled>
      <UnrelatedBusinessIncome>1</UnrelatedBusinessIncome>
      <Form990-TFiled>1</Form990-TFiled>
      <ForeignFinancialAccount>0</ForeignFinancialAccount>
      <ProhibitedTaxShelterTrans>0</ProhibitedTaxShelterTrans>
      <TaxablePartyNotification>0</TaxablePartyNotification>
      <NonDeductibleContributions>0</NonDeductibleContributions>
      <FundsToPayPremiums>0</FundsToPayPremiums>
      <PremiumsPaid>0</PremiumsPaid>
      <IndoorTanningServices>0</IndoorTanningServices>
      <InfoInScheduleOPartVI>X</InfoInScheduleOPartVI>
      <NbrVotingGoverningBodyMembers>22</NbrVotingGoverningBodyMembers>
      <NumberIndependentVotingMembers>22</NumberIndependentVotingMembers>
      <FamilyOrBusinessRelationship>0</FamilyOrBusinessRelationship>
      <DelegationOfManagementDuties>0</DelegationOfManagementDuties>
      <ChangesToOrganizingDocs>0</ChangesToOrganizingDocs>
      <MaterialDiversionOrMisuse>0</MaterialDiversionOrMisuse>
      <MembersOrStockholders>1</MembersOrStockholders>
      <ElectionOfBoardMembers>1</ElectionOfBoardMembers>
      <DecisionsSubjectToApproval>1</DecisionsSubjectToApproval>
      <MinutesOfGoverningBody>1</MinutesOfGoverningBody>
      <MinutesOfCommittees>1</MinutesOfCommittees>
      <OfficerMailingAddress>0</OfficerMailingAddress>
      <LocalChapters>1</LocalChapters>
      <PoliciesReferenceChapters>1</PoliciesReferenceChapters>
      <Form990ProvidedToGoverningBody>1</Form990ProvidedToGoverningBody>
      <ConflictOfInterestPolicy>1</ConflictOfInterestPolicy>
      <AnnualDisclosureCoveredPersons>1</AnnualDisclosureCoveredPersons>
      <RegularMonitoringEnforcement>0</RegularMonitoringEnforcement>
      <WhistleblowerPolicy>1</WhistleblowerPolicy>
      <DocumentRetentionPolicy>1</DocumentRetentionPolicy>
      <CompensationProcessCEO>1</CompensationProcessCEO>
      <CompensationProcessOther>1</CompensationProcessOther>
      <InvestmentInJointVenture>0</InvestmentInJointVenture>
      <StatesWhereCopyOfReturnIsFiled>MA</StatesWhereCopyOfReturnIsFiled>
      <UponRequest>X</UponRequest>
      <TheBooksAreInCareOf>
        <NameBusiness>
          <BusinessNameLine1>MDS CO KATHLEEN BOYCE</BusinessNameLine1>
        </NameBusiness>
        <TelephoneNumber>5084809747</TelephoneNumber>
        <AddressUS>
          <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
          <City>SOUTHBOROUGH</City>
          <State>MA</State>
          <ZIPCode>01745</ZIPCode>
        </AddressUS>
      </TheBooksAreInCareOf>
      <Form990PartVIISectionA>
        <NamePerson>CHARLES L SILVIUS DDS</NamePerson>
        <Title>PRESIDENT</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>PAULA J FRIEDMAN DDS</NamePerson>
        <Title>PRESIDENT - ELECT</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>MICHAEL WASSERMAN DDS</NamePerson>
        <Title>VICE PRESIDENT</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>THOMAS TORRISI DDS</NamePerson>
        <Title>SPEAKER OF THE HOUSE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>TONY N GIAMBERARDINO DMD</NamePerson>
        <Title>SECRETARY</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>WILLIAM R DENNIS DDS</NamePerson>
        <Title>ASSISTANT SECRETARY</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>MICHAEL A JUSSEAUME DDS</NamePerson>
        <Title>TREASURER</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>HOWARD ZOLOT DMD</NamePerson>
        <Title>ASSISTANT TREASURER</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>JOHN P FISHER DDS</NamePerson>
        <Title>IMMEDIATE PAST PRESIDENT</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>RAYMOND JAY WISE DDS</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>RICHARD D MARCHAND DMD</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>TOFIGH RAAYAI DMD</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>THOMAS A TROWBRIDGE DDS MD</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>JOHN CHRIS OWEN</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>JANIS C MORIARTY</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>DAVID B BECKER DMD</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>N PETER HJORTH DMD</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>RAYMOND K MARTIN DDS</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>DAVID P LUSTBADER DMD</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>EDWARD J WELCH DDS</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>STEPHEN J SHEA DDS</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>EDWARD SWIDERSKI DDS</NamePerson>
        <Title>TRUSTEE</Title>
        <AverageHoursPerWeek>4.00</AverageHoursPerWeek>
        <IndividualTrusteeOrDirector>X</IndividualTrusteeOrDirector>
        <ReportableCompFromOrganization>0</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>0</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>KATHLEEN BOYCE</NamePerson>
        <Title>CHIEF FINANCIAL OFFICER</Title>
        <AverageHoursPerWeek>35.00</AverageHoursPerWeek>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>156817</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>18074</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>ROBERT BOOSE</NamePerson>
        <Title>EXECUTIVE DIRECTOR</Title>
        <AverageHoursPerWeek>35.00</AverageHoursPerWeek>
        <Officer>X</Officer>
        <ReportableCompFromOrganization>264849</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>36802</OtherCompensation>
      </Form990PartVIISectionA>
      <Form990PartVIISectionA>
        <NamePerson>KAREN RAFELD</NamePerson>
        <Title>ASSISTANT EXECUTIVE DIRECT</Title>
        <AverageHoursPerWeek>35.00</AverageHoursPerWeek>
        <KeyEmployee>X</KeyEmployee>
        <ReportableCompFromOrganization>157789</ReportableCompFromOrganization>
        <ReportableCompFromRelatedOrgs>0</ReportableCompFromRelatedOrgs>
        <OtherCompensation>21010</OtherCompensation>
      </Form990PartVIISectionA>
      <TotalReportableCompFromOrg>579455</TotalReportableCompFromOrg>
      <TotalReportableCompFrmRltdOrgs>0</TotalReportableCompFrmRltdOrgs>
      <TotalOtherCompensation>75886</TotalOtherCompensation>
      <NumberIndividualsGT100K>3</NumberIndividualsGT100K>
      <FormersListed>0</FormersListed>
      <TotalCompGT150K>1</TotalCompGT150K>
      <CompensationFromOtherSources>0</CompensationFromOtherSources>
      <ContractorCompensation>
        <NameOfContractor>
          <NameBusiness>
            <BusinessNameLine1>MASSACHUSETTS CONVENTION CENTER AUTHORIT</BusinessNameLine1>
          </NameBusiness>
        </NameOfContractor>
        <AddressOfContractor>
          <AddressUS>
            <AddressLine1>415 SUMMER STREET</AddressLine1>
            <City>BOSTON</City>
            <State>MA</State>
            <ZIPCode>02210</ZIPCode>
          </AddressUS>
        </AddressOfContractor>
        <DescriptionOfServices>EVENT SPACE RENTAL</DescriptionOfServices>
        <Compensation>397415</Compensation>
      </ContractorCompensation>
      <ContractorCompensation>
        <NameOfContractor>
          <NameBusiness>
            <BusinessNameLine1>LEVY PREMIUM FOOD SERVICE</BusinessNameLine1>
          </NameBusiness>
        </NameOfContractor>
        <AddressOfContractor>
          <AddressUS>
            <AddressLine1>980 N MICHIGAN AVENUE</AddressLine1>
            <City>CHICAGO</City>
            <State>IL</State>
            <ZIPCode>60611</ZIPCode>
          </AddressUS>
        </AddressOfContractor>
        <DescriptionOfServices>CATERING</DescriptionOfServices>
        <Compensation>304678</Compensation>
      </ContractorCompensation>
      <ContractorCompensation>
        <NameOfContractor>
          <NameBusiness>
            <BusinessNameLine1>PROJECTION INC</BusinessNameLine1>
          </NameBusiness>
        </NameOfContractor>
        <AddressOfContractor>
          <AddressUS>
            <AddressLine1>415 SUMMER STREET</AddressLine1>
            <City>BOSTON</City>
            <State>MA</State>
            <ZIPCode>02210</ZIPCode>
          </AddressUS>
        </AddressOfContractor>
        <DescriptionOfServices>AUDIO / VISUAL SERVICES</DescriptionOfServices>
        <Compensation>259809</Compensation>
      </ContractorCompensation>
      <ContractorCompensation>
        <NameOfContractor>
          <NameBusiness>
            <BusinessNameLine1>PRINT RESOURCES INC</BusinessNameLine1>
          </NameBusiness>
        </NameOfContractor>
        <AddressOfContractor>
          <AddressUS>
            <AddressLine1>2720 19TH STREET</AddressLine1>
            <City>BIRMINGHAM</City>
            <State>AL</State>
            <ZIPCode>35209</ZIPCode>
          </AddressUS>
        </AddressOfContractor>
        <DescriptionOfServices>PRINTING</DescriptionOfServices>
        <Compensation>212868</Compensation>
      </ContractorCompensation>
      <ContractorCompensation>
        <NameOfContractor>
          <NameBusiness>
            <BusinessNameLine1>RHODE PLANNING &amp; MANAGEMENT SERVICES IN</BusinessNameLine1>
          </NameBusiness>
        </NameOfContractor>
        <AddressOfContractor>
          <AddressUS>
            <AddressLine1>640 TEN ROAD</AddressLine1>
            <City>NORTH KINGSTOWN</City>
            <State>RI</State>
            <ZIPCode>02852</ZIPCode>
          </AddressUS>
        </AddressOfContractor>
        <DescriptionOfServices>TRANSPORTATION</DescriptionOfServices>
        <Compensation>209979</Compensation>
      </ContractorCompensation>
      <NumberOfContractorsGT100K>5</NumberOfContractorsGT100K>
      <AllOtherContributions>38075</AllOtherContributions>
      <TotalContributions>38075</TotalContributions>
      <ProgramServiceRevenue>
        <Description>YANKEE DENTAL CONGRESS</Description>
        <BusinessCode>900099</BusinessCode>
        <TotalRevenueColumn>6464231</TotalRevenueColumn>
        <ExclusionAmount>6464231</ExclusionAmount>
      </ProgramServiceRevenue>
      <ProgramServiceRevenue>
        <Description>MEMBERSHIP DUES</Description>
        <BusinessCode>900099</BusinessCode>
        <TotalRevenueColumn>2116080</TotalRevenueColumn>
        <RelatedOrExemptFunctionIncome>2116080</RelatedOrExemptFunctionIncome>
      </ProgramServiceRevenue>
      <ProgramServiceRevenue>
        <Description>CONFERENCES AND WORKSH</Description>
        <BusinessCode>900099</BusinessCode>
        <TotalRevenueColumn>361709</TotalRevenueColumn>
        <RelatedOrExemptFunctionIncome>361709</RelatedOrExemptFunctionIncome>
      </ProgramServiceRevenue>
      <ProgramServiceRevenue>
        <Description>CONTINUING EDUCATION</Description>
        <BusinessCode>900099</BusinessCode>
        <TotalRevenueColumn>282307</TotalRevenueColumn>
        <RelatedOrExemptFunctionIncome>282307</RelatedOrExemptFunctionIncome>
      </ProgramServiceRevenue>
      <ProgramServiceRevenue>
        <Description>ADVERTISING</Description>
        <BusinessCode>541800</BusinessCode>
        <TotalRevenueColumn>155045</TotalRevenueColumn>
        <UnrelatedBusinessRevenue>155045</UnrelatedBusinessRevenue>
      </ProgramServiceRevenue>
      <TotalProgramServiceRevenue>9379372</TotalProgramServiceRevenue>
      <InvestmentIncome>
        <TotalRevenueColumn>278686</TotalRevenueColumn>
        <ExclusionAmount>278686</ExclusionAmount>
      </InvestmentIncome>
      <RoyaltiesRevenue>
        <TotalRevenueColumn>278192</TotalRevenueColumn>
        <ExclusionAmount>278192</ExclusionAmount>
      </RoyaltiesRevenue>
      <GrossRents>
        <Real>306613</Real>
      </GrossRents>
      <LessRentalExpenses>
        <Real>505927</Real>
      </LessRentalExpenses>
      <RentalIncomeOrLoss>
        <Real>-199314</Real>
      </RentalIncomeOrLoss>
      <NetRentalIncomeOrLoss>
        <TotalRevenueColumn>-199314</TotalRevenueColumn>
        <UnrelatedBusinessRevenue>-186120</UnrelatedBusinessRevenue>
        <ExclusionAmount>-13194</ExclusionAmount>
      </NetRentalIncomeOrLoss>
      <GrossAmountSalesAssets>
        <Securities>6053047</Securities>
      </GrossAmountSalesAssets>
      <LessCostOthBasisSalesExpenses>
        <Securities>5965524</Securities>
        <Other>6191</Other>
      </LessCostOthBasisSalesExpenses>
      <GainOrLoss>
        <Securities>87523</Securities>
        <Other>-6191</Other>
      </GainOrLoss>
      <NetGainOrLossInvestments>
        <TotalRevenueColumn>81332</TotalRevenueColumn>
        <ExclusionAmount>81332</ExclusionAmount>
      </NetGainOrLossInvestments>
      <OtherRevenueMisc>
        <Description>MANAGEMENT FEE</Description>
        <BusinessCode>900099</BusinessCode>
        <TotalRevenueColumn>10833</TotalRevenueColumn>
        <RelatedOrExemptFunctionIncome>10833</RelatedOrExemptFunctionIncome>
      </OtherRevenueMisc>
      <OtherRevenueMisc>
        <Description>EQUITY IN WHOLLY OWNED</Description>
        <BusinessCode>900099</BusinessCode>
        <TotalRevenueColumn>-57452</TotalRevenueColumn>
        <ExclusionAmount>-57452</ExclusionAmount>
      </OtherRevenueMisc>
      <MiscellaneousRevenue>
        <TotalRevenueColumn>46799</TotalRevenueColumn>
        <RelatedOrExemptFunctionIncome>46799</RelatedOrExemptFunctionIncome>
      </MiscellaneousRevenue>
      <TotalOtherRevenue>180</TotalOtherRevenue>
      <TotalRevenue>
        <TotalRevenueColumn>9856523</TotalRevenueColumn>
        <RelatedOrExemptFunctionIncome>2817728</RelatedOrExemptFunctionIncome>
        <UnrelatedBusinessRevenue>-31075</UnrelatedBusinessRevenue>
        <ExclusionAmount>7031795</ExclusionAmount>
      </TotalRevenue>
      <GrantsToDomesticOrgs>
        <Total>75279</Total>
      </GrantsToDomesticOrgs>
      <CompCurrentOfficersDirectors>
        <Total>485404</Total>
      </CompCurrentOfficersDirectors>
      <OtherSalariesAndWages>
        <Total>2329504</Total>
      </OtherSalariesAndWages>
      <PensionPlanContributions>
        <Total>170615</Total>
      </PensionPlanContributions>
      <OtherEmployeeBenefits>
        <Total>207870</Total>
      </OtherEmployeeBenefits>
      <PayrollTaxes>
        <Total>217611</Total>
      </PayrollTaxes>
      <FeesForServicesLegal>
        <Total>206200</Total>
      </FeesForServicesLegal>
      <FeesForServicesAccounting>
        <Total>33929</Total>
      </FeesForServicesAccounting>
      <OfficeExpenses>
        <Total>294698</Total>
      </OfficeExpenses>
      <Occupancy>
        <Total>109782</Total>
      </Occupancy>
      <Travel>
        <Total>33537</Total>
      </Travel>
      <ConferencesMeetings>
        <Total>2829116</Total>
      </ConferencesMeetings>
      <Interest>
        <Total>91193</Total>
      </Interest>
      <DepreciationDepletion>
        <Total>154641</Total>
      </DepreciationDepletion>
      <Insurance>
        <Total>38065</Total>
      </Insurance>
      <OtherExpenses>
        <Description>SEMINARS AND WORKSHOPS</Description>
        <Total>411537</Total>
      </OtherExpenses>
      <OtherExpenses>
        <Description>INITIATIVES</Description>
        <Total>324132</Total>
      </OtherExpenses>
      <OtherExpenses>
        <Description>DELEGATES MEETINGS</Description>
        <Total>259552</Total>
      </OtherExpenses>
      <OtherExpenses>
        <Description>PUBLIC AWARENESS PROGRA</Description>
        <Total>257351</Total>
      </OtherExpenses>
      <AllOtherExpenses>
        <Total>1067738</Total>
      </AllOtherExpenses>
      <TotalFunctionalExpenses>
        <Total>9597754</Total>
      </TotalFunctionalExpenses>
      <CashNonInterestBearing>
        <BOY>911481</BOY>
        <EOY>322977</EOY>
      </CashNonInterestBearing>
      <SavingsAndTempCashInvestments>
        <BOY>1742541</BOY>
        <EOY>1743559</EOY>
      </SavingsAndTempCashInvestments>
      <AccountsReceivable>
        <BOY>142204</BOY>
        <EOY>140549</EOY>
      </AccountsReceivable>
      <PrepaidExpensesDeferredCharges>
        <BOY>413876</BOY>
        <EOY>338202</EOY>
      </PrepaidExpensesDeferredCharges>
      <LandBuildingsEquipmentBasis>7661177</LandBuildingsEquipmentBasis>
      <LandBldgEquipmentAccumDeprec>2253511</LandBldgEquipmentAccumDeprec>
      <LandBuildingsEquipmentBasisNet>
        <BOY>5589751</BOY>
        <EOY>5407666</EOY>
      </LandBuildingsEquipmentBasisNet>
      <InvestmentsPubTradedSecurities>
        <BOY>7109626</BOY>
        <EOY>6948973</EOY>
      </InvestmentsPubTradedSecurities>
      <InvestmentsOtherSecurities>
        <BOY>277989</BOY>
        <EOY>301650</EOY>
      </InvestmentsOtherSecurities>
      <OtherAssetsTotal>
        <BOY>32818</BOY>
        <EOY>29301</EOY>
      </OtherAssetsTotal>
      <TotalAssets>
        <BOY>16220286</BOY>
        <EOY>15232877</EOY>
      </TotalAssets>
      <AccountsPayableAccruedExpenses>
        <BOY>648824</BOY>
        <EOY>647289</EOY>
      </AccountsPayableAccruedExpenses>
      <DeferredRevenue>
        <BOY>2173582</BOY>
        <EOY>2149201</EOY>
      </DeferredRevenue>
      <MortNotesPyblSecuredInvestProp>
        <BOY>4612055</BOY>
        <EOY>4474784</EOY>
      </MortNotesPyblSecuredInvestProp>
      <OtherLiabilities>
        <BOY>1016464</BOY>
        <EOY>310459</EOY>
      </OtherLiabilities>
      <TotalLiabilities>
        <BOY>8450925</BOY>
        <EOY>7581733</EOY>
      </TotalLiabilities>
      <FollowSFAS117>X</FollowSFAS117>
      <UnrestrictedNetAssets>
        <BOY>7754869</BOY>
        <EOY>7651144</EOY>
      </UnrestrictedNetAssets>
      <TemporarilyRestrictedNetAssets>
        <BOY>14492</BOY>
        <EOY>0</EOY>
      </TemporarilyRestrictedNetAssets>
      <TotalNetAssetsFundBalances>
        <BOY>7769361</BOY>
        <EOY>7651144</EOY>
      </TotalNetAssetsFundBalances>
      <TotalLiabNetAssetsFundBalances>
        <BOY>16220286</BOY>
        <EOY>15232877</EOY>
      </TotalLiabNetAssetsFundBalances>
      <InfoInScheduleOPartXI>X</InfoInScheduleOPartXI>
      <ReconcilationRevenueExpenses>258769</ReconcilationRevenueExpenses>
      <ReconcilationOtherChanges>-376986</ReconcilationOtherChanges>
      <InfoInScheduleOPartXII>X</InfoInScheduleOPartXII>
      <MethodOfAccountingAccrual>X</MethodOfAccountingAccrual>
      <AccountantCompileOrReview>0</AccountantCompileOrReview>
      <FSAudited>1</FSAudited>
      <AuditCommittee>1</AuditCommittee>
      <FinancialStatementConsolidated>X</FinancialStatementConsolidated>
      <FederalGrantAuditRequired>0</FederalGrantAuditRequired>
    </IRS990>
    <IRS990ScheduleC documentId="RetDoc1039700001">
      <SubstantiallyAllDuesNondeduct>0</SubstantiallyAllDuesNondeduct>
      <OnlyInHouseLobbying>0</OnlyInHouseLobbying>
      <AgreeToCarryoverPriorYear>0</AgreeToCarryoverPriorYear>
      <DuesAssessments>2116080</DuesAssessments>
      <NonDedLobbyPoliticalCurrent>434986</NonDedLobbyPoliticalCurrent>
      <NonDedLobbyPoliticalTotal>434986</NonDedLobbyPoliticalTotal>
      <AggrAmtReportedInDuesNotices>503627</AggrAmtReportedInDuesNotices>
      <TaxableAmount>-68641</TaxableAmount>
    </IRS990ScheduleC>
    <IRS990ScheduleD documentId="RetDoc1040000001">
      <Land>
        <OtherCostOrOtherBasis>925873</OtherCostOrOtherBasis>
        <BookValue>925873</BookValue>
      </Land>
      <Buildings>
        <OtherCostOrOtherBasis>5121510</OtherCostOrOtherBasis>
        <Depreciation>1067959</Depreciation>
        <BookValue>4053551</BookValue>
      </Buildings>
      <LeaseholdImprovements>
        <OtherCostOrOtherBasis>375943</OtherCostOrOtherBasis>
        <Depreciation>113429</Depreciation>
        <BookValue>262514</BookValue>
      </LeaseholdImprovements>
      <Equipment>
        <OtherCostOrOtherBasis>807339</OtherCostOrOtherBasis>
        <Depreciation>700520</Depreciation>
        <BookValue>106819</BookValue>
      </Equipment>
      <OtherLandBuildings>
        <OtherCostOrOtherBasis>430512</OtherCostOrOtherBasis>
        <Depreciation>371603</Depreciation>
        <BookValue>58909</BookValue>
      </OtherLandBuildings>
      <TotalOfBookValueLandBuildings>5407666</TotalOfBookValueLandBuildings>
      <OtherLiabilities>
        <Description>CUSTOMER DEPOSITS</Description>
        <Amount>27399</Amount>
      </OtherLiabilities>
      <OtherLiabilities>
        <Description>MISCELLANEOUS</Description>
        <Amount>77698</Amount>
      </OtherLiabilities>
      <OtherLiabilities>
        <Description>DUE TO (FROM)</Description>
        <Amount>205362</Amount>
      </OtherLiabilities>
      <TotalOfAmounts>310459</TotalOfAmounts>
      <Form990ScheduleDPartXIV>
        <Explanation>MASSACHUSETTS DENTAL SOCIETY (MDS) FOLLOWS THE ACCOUNTING FOR UNCERTAINTY IN INCOME TAXES STANDARD WHICH REQUIRES MDS TO REPORT UNCERTAIN TAX POSITIONS, RELATED INTEREST AND PENALTIES, AND TO ADJUST THEIR ASSETS AND LIABILITIES RELATED TO UNRECOGNIZED TAX BENEFITS AND ACCRUED INTEREST AND PENALTIES ACCORDINGLY. AS OF APRIL 30, 2012, MDS DETERMINED THAT THERE ARE NO MATERIAL UNRECOGNIZED TAX BENEFITS TO REPORT. INFORMATION AND INCOME TAX RETURNS FILED FOR THE YEARS ENDED APRIL 30, 2011, 2010 AND 2009, REMAIN SUBJECT TO EXAMINATION BY THE INTERNAL REVENUE SERVICE AND MASSACHUSETTS STATE JURISDICTIONS.</Explanation>
      </Form990ScheduleDPartXIV>
    </IRS990ScheduleD>
    <IRS990ScheduleI documentId="RetDoc1041900001">
      <RecordsMaintained>1</RecordsMaintained>
      <RecipientTable>
        <RecipientNameBusiness>
          <BusinessNameLine1>DCD (DOCTORS CARING FOR DOCTORS)</BusinessNameLine1>
        </RecipientNameBusiness>
        <AddressUS>
          <AddressLine1>PO BOX 716</AddressLine1>
          <City>ANDOVER</City>
          <State>MA</State>
          <ZIPCode>01810</ZIPCode>
        </AddressUS>
        <IRCSection>170(B)(1)(A)(V)</IRCSection>
        <AmountOfCashGrant>48000</AmountOfCashGrant>
        <PurposeOfGrant>THESE GRANT MONIES SUPPORT THE ACITIVITIES OF THAT ORGANIZATION THAT WORKS IN CONJUNCTION WITH THE MDS WELL-BEING COMMITTEE. MDS HAS PAID OUT THIS GRANT FOR MANY YEARS AND IT IS PAID IN EQUAL MONTHLY INSTALLMENTS OVER THE COURSE OF THE FISCAL YEAR.</PurposeOfGrant>
      </RecipientTable>
      <TotalNbrOf501C3AndGovtGrants>1</TotalNbrOf501C3AndGovtGrants>
    </IRS990ScheduleI>
    <IRS990ScheduleJ documentId="RetDoc1042400001">
      <BoardOrCommitteeApproval>X</BoardOrCommitteeApproval>
      <SeverancePayment>0</SeverancePayment>
      <SupplementalNonqualRetirePlan>0</SupplementalNonqualRetirePlan>
      <EquityBasedCompArrangement>0</EquityBasedCompArrangement>
      <Form990ScheduleJPartII>
        <NamePerson>KATHLEEN BOYCE</NamePerson>
        <BaseCompensationFilingOrg>156817</BaseCompensationFilingOrg>
        <CompBasedOnRelatedOrgs>0</CompBasedOnRelatedOrgs>
        <BonusFilingOrg>0</BonusFilingOrg>
        <BonusRelatedOrgs>0</BonusRelatedOrgs>
        <OtherCompensationFilingOrg>0</OtherCompensationFilingOrg>
        <OtherCompensationRelatedOrgs>0</OtherCompensationRelatedOrgs>
        <DeferredCompFilingOrg>0</DeferredCompFilingOrg>
        <DeferredCompRelatedOrgs>0</DeferredCompRelatedOrgs>
        <NontaxableBenefitsFilingOrg>18074</NontaxableBenefitsFilingOrg>
        <NontaxableBenefitsRelatedOrgs>0</NontaxableBenefitsRelatedOrgs>
        <TotalCompensationFilingOrg>174891</TotalCompensationFilingOrg>
        <TotalCompensationRelatedOrgs>0</TotalCompensationRelatedOrgs>
        <CompReportPrior990FilingOrg>0</CompReportPrior990FilingOrg>
        <CompReportPrior990RelatedOrgs>0</CompReportPrior990RelatedOrgs>
      </Form990ScheduleJPartII>
      <Form990ScheduleJPartII>
        <NamePerson>ROBERT BOOSE</NamePerson>
        <BaseCompensationFilingOrg>264849</BaseCompensationFilingOrg>
        <CompBasedOnRelatedOrgs>0</CompBasedOnRelatedOrgs>
        <BonusFilingOrg>0</BonusFilingOrg>
        <BonusRelatedOrgs>0</BonusRelatedOrgs>
        <OtherCompensationFilingOrg>0</OtherCompensationFilingOrg>
        <OtherCompensationRelatedOrgs>0</OtherCompensationRelatedOrgs>
        <DeferredCompFilingOrg>0</DeferredCompFilingOrg>
        <DeferredCompRelatedOrgs>0</DeferredCompRelatedOrgs>
        <NontaxableBenefitsFilingOrg>36802</NontaxableBenefitsFilingOrg>
        <NontaxableBenefitsRelatedOrgs>0</NontaxableBenefitsRelatedOrgs>
        <TotalCompensationFilingOrg>301651</TotalCompensationFilingOrg>
        <TotalCompensationRelatedOrgs>0</TotalCompensationRelatedOrgs>
        <CompReportPrior990FilingOrg>0</CompReportPrior990FilingOrg>
        <CompReportPrior990RelatedOrgs>0</CompReportPrior990RelatedOrgs>
      </Form990ScheduleJPartII>
      <Form990ScheduleJPartII>
        <NamePerson>KAREN RAFELD</NamePerson>
        <BaseCompensationFilingOrg>157789</BaseCompensationFilingOrg>
        <CompBasedOnRelatedOrgs>0</CompBasedOnRelatedOrgs>
        <BonusFilingOrg>0</BonusFilingOrg>
        <BonusRelatedOrgs>0</BonusRelatedOrgs>
        <OtherCompensationFilingOrg>0</OtherCompensationFilingOrg>
        <OtherCompensationRelatedOrgs>0</OtherCompensationRelatedOrgs>
        <DeferredCompFilingOrg>0</DeferredCompFilingOrg>
        <DeferredCompRelatedOrgs>0</DeferredCompRelatedOrgs>
        <NontaxableBenefitsFilingOrg>21010</NontaxableBenefitsFilingOrg>
        <NontaxableBenefitsRelatedOrgs>0</NontaxableBenefitsRelatedOrgs>
        <TotalCompensationFilingOrg>178799</TotalCompensationFilingOrg>
        <TotalCompensationRelatedOrgs>0</TotalCompensationRelatedOrgs>
        <CompReportPrior990FilingOrg>0</CompReportPrior990FilingOrg>
        <CompReportPrior990RelatedOrgs>0</CompReportPrior990RelatedOrgs>
      </Form990ScheduleJPartII>
    </IRS990ScheduleJ>
    <IRS990ScheduleO documentId="RetDoc1044400001">
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION A, LINE 6</ReturnReference>
        <Explanation>THE ORGANIZATION'S MEMBERSHIP IS COMPRISED OF ORAL HEALTH CARE PROFESSIONALS IN MASSACHUSETTS.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION A, LINE 7A</ReturnReference>
        <Explanation>THE ORGANIZATION'S MEMBERS ELECT THE DELEGATES, WHO REPRESENT THEM IN VOTING TO ELECT THE GOVERNING BODY, THE BOARD OF TRUSTEES.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION A, LINE 7B</ReturnReference>
        <Explanation>THE ANNUAL MEETING OF DELEGATES HAS THE RIGHT TO ADDRESS ANY ITEMS OR ACTIONS TAKEN BY THE BOARD DURING THE YEAR.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION B, LINE 11</ReturnReference>
        <Explanation>THE FORM 990 IS PROVIDED TO THE TRUSTEES BEFORE FILING. THE CFO REVIEWS THE RETURN PRIOR TO BEING FILED.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION B, LINE 12</ReturnReference>
        <Explanation>ALL BOARD MEMBERS SIGN THE CONFLICT OF INTEREST POLICY AND ANY CONFLICTS ARE ANNOUNCED AT THE BEGINNING OF EACH BOARD MEETING.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION B, LINE 15</ReturnReference>
        <Explanation>THE EXECUTIVE DIRECTOR'S COMPENSATION IS DETERMINED BY THE COMPENSATION COMMITTEE OF THE BOARD OF TRUSTEES. THE CHIEF FINANCIAL OFFICER'S SALARY IS DETERMINED BY THE EXECUTIVE DIRECTOR.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART VI, SECTION C, LINE 19</ReturnReference>
        <Explanation>THE ORGANIZATION MAKES ITS GOVERNING DOCUMENTS, CONFLICT OF INTEREST POLICY AND FINANCIAL STATEMENTS AVAILABLE TO THE PUBLIC UPON REQUEST.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <Identifier>CHANGES IN NET ASSETS OR FUND BALANCES:</Identifier>
        <ReturnReference>FORM 990, PART XI, LINE 5:</ReturnReference>
        <Explanation>NET UNREALIZED LOSSES ON INVESTMENTS: -278,812. ADUSTMENT DISTRICT INVESTMENTS -98,174. TOTAL TO FORM 990, PART XI, LINE 5: -376,986.</Explanation>
      </GeneralExplanation>
      <GeneralExplanation>
        <ReturnReference>FORM 990, PART XI, LINE 2C</ReturnReference>
        <Explanation>THE BOARD OF TRUSTEES ASSUMES RESPONSIBILITY FOR THE OVERSIGHT OF THE AUDIT OF ITS FINANCIAL STATEMENTS AND SELECTION OF THE INDEPENDENT AUDITOR.</Explanation>
      </GeneralExplanation>
    </IRS990ScheduleO>
    <IRS990ScheduleR documentId="RetDoc1043400001">
      <Form990ScheduleRPartI>
        <NameOfDisregardedEntity>
          <BusinessNameLine1>FIRMIN JOINT VENTURE LLC</BusinessNameLine1>
        </NameOfDisregardedEntity>
        <AddressUS>
          <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
          <City>SOUTHBOROUGH</City>
          <State>MA</State>
          <ZIPCode>01745</ZIPCode>
        </AddressUS>
        <EIN>043446721</EIN>
        <PrimaryActivities>TO OWN MDS' PRINCIPAL PROPERTY</PrimaryActivities>
        <LegalDomicileState>MA</LegalDomicileState>
        <TotalIncome>714058</TotalIncome>
        <EOYAssets>5018084</EOYAssets>
        <DirectControllingEntityName>
          <BusinessNameLine1>MASSACHUSETTS DENTAL SOCIETY</BusinessNameLine1>
        </DirectControllingEntityName>
      </Form990ScheduleRPartI>
      <Form990ScheduleRPartII>
        <NameOfDisregardedEntity>
          <BusinessNameLine1>MDS FOUNDATION INC</BusinessNameLine1>
        </NameOfDisregardedEntity>
        <AddressUS>
          <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
          <City>SOUTHBOROUGH</City>
          <State>MA</State>
          <ZIPCode>01715</ZIPCode>
        </AddressUS>
        <EIN>043466040</EIN>
        <PrimaryActivities>IMPROVE ORAL HEALTH CARE OF MASSACHUSETTS RESIDENTS</PrimaryActivities>
        <LegalDomicileState>MA</LegalDomicileState>
        <ExemptCodeSection>501(C)(3)</ExemptCodeSection>
        <PublicCharityStatus>LINE 11C, III-FI</PublicCharityStatus>
        <DirectControllingEntityName>
          <BusinessNameLine1>MASSACHUSETTS DENTAL SOCIETY</BusinessNameLine1>
        </DirectControllingEntityName>
        <ControlledOrg>0</ControlledOrg>
      </Form990ScheduleRPartII>
      <Form990ScheduleRPartII>
        <NameOfDisregardedEntity>
          <BusinessNameLine1>MASSACHUSETTS DENTAL SOCIETY RELIEF FUND INC</BusinessNameLine1>
        </NameOfDisregardedEntity>
        <AddressUS>
          <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
          <City>SOUTHBOROUGH</City>
          <State>MA</State>
          <ZIPCode>01715</ZIPCode>
        </AddressUS>
        <EIN>046139122</EIN>
        <PrimaryActivities>HELP DENTISTS IN NEED</PrimaryActivities>
        <LegalDomicileState>MA</LegalDomicileState>
        <ExemptCodeSection>501(C)(3)</ExemptCodeSection>
        <PublicCharityStatus>LINE 11A, I</PublicCharityStatus>
        <DirectControllingEntityName>
          <BusinessNameLine1>MASSACHUSETTS DENTAL SOCIETY</BusinessNameLine1>
        </DirectControllingEntityName>
        <ControlledOrg>0</ControlledOrg>
      </Form990ScheduleRPartII>
      <Form990ScheduleRPartIV>
        <NameOfRelatedOrg>
          <BusinessNameLine1>MDS INSURANCE SERVICES INC</BusinessNameLine1>
        </NameOfRelatedOrg>
        <AddressUS>
          <AddressLine1>TWO WILLOW STREET SUITE 200</AddressLine1>
          <City>SOUTHBOROUGH</City>
          <State>MA</State>
          <ZIPCode>01745</ZIPCode>
        </AddressUS>
        <EIN>043432374</EIN>
        <PrimaryActivity>INSURANCE AGENT</PrimaryActivity>
        <LegalDomicileState>MA</LegalDomicileState>
        <DirectControllingEntityName>
          <BusinessNameLine1>MASSACHUSETTS DENTAL SOCIETY</BusinessNameLine1>
        </DirectControllingEntityName>
        <TypeOfEntity>C</TypeOfEntity>
        <ShareOfTotalIncome>40986</ShareOfTotalIncome>
        <ShareOfEOYAssets>301650</ShareOfEOYAssets>
        <PercentageOwnership>1.00000</PercentageOwnership>
      </Form990ScheduleRPartIV>
      <ReceiptOfIntAnnRentsRoyalties>0</ReceiptOfIntAnnRentsRoyalties>
      <GiftGrantOrCapContrToOtherOrg>1</GiftGrantOrCapContrToOtherOrg>
      <GiftGrantOrCapContrFrOtherOrg>0</GiftGrantOrCapContrFrOtherOrg>
      <LoansOrGuaranteesToOtherOrg>0</LoansOrGuaranteesToOtherOrg>
      <LoansOrGuaranteesFromOtherOrg>0</LoansOrGuaranteesFromOtherOrg>
      <SaleOfAssetsToOtherOrg>0</SaleOfAssetsToOtherOrg>
      <PurchaseOfAssetsFromOtherOrg>0</PurchaseOfAssetsFromOtherOrg>
      <ExchangeOfAssets>0</ExchangeOfAssets>
      <RentalOfFacilitiesToOtherOrgs>0</RentalOfFacilitiesToOtherOrgs>
      <RentalOfFacilitiesFrOtherOrgs>0</RentalOfFacilitiesFrOtherOrgs>
      <PerformOfServicesForOtherOrgs>0</PerformOfServicesForOtherOrgs>
      <PerformOfServicesByOtherOrgs>0</PerformOfServicesByOtherOrgs>
      <SharingOfFacilities>1</SharingOfFacilities>
      <SharingOfPaidEmployees>0</SharingOfPaidEmployees>
      <ReimbursementPaidToOtherOrg>1</ReimbursementPaidToOtherOrg>
      <ReimbursementPaidByOtherOrg>1</ReimbursementPaidByOtherOrg>
      <OtherTransferToOtherOrg>0</OtherTransferToOtherOrg>
      <OtherTransferFromOtherOrg>0</OtherTransferFromOtherOrg>
      <TransactionsRelatedOrgsTable>
        <NameOfOtherOrganization>
          <BusinessNameLine1>MDS FOUNDATION INC</BusinessNameLine1>
        </NameOfOtherOrganization>
        <TransactionType>B</TransactionType>
        <AmountInvolved>324132</AmountInvolved>
        <MethodOfAmtDetermination>AMOUNT OF CONTRIBUTION AWARDED</MethodOfAmtDetermination>
      </TransactionsRelatedOrgsTable>
      <TransactionsRelatedOrgsTable>
        <NameOfOtherOrganization>
          <BusinessNameLine1>MDS FOUNDATION INC</BusinessNameLine1>
        </NameOfOtherOrganization>
        <TransactionType>M</TransactionType>
        <AmountInvolved>38000</AmountInvolved>
        <MethodOfAmtDetermination>VALUE OF SERVICES PROVIDED</MethodOfAmtDetermination>
      </TransactionsRelatedOrgsTable>
      <TransactionsRelatedOrgsTable>
        <NameOfOtherOrganization>
          <BusinessNameLine1>MDS FOUNDATION INC</BusinessNameLine1>
        </NameOfOtherOrganization>
        <TransactionType>O</TransactionType>
        <AmountInvolved>6603</AmountInvolved>
        <MethodOfAmtDetermination>AMOUNT TO FROM MDSF</MethodOfAmtDetermination>
      </TransactionsRelatedOrgsTable>
      <TransactionsRelatedOrgsTable>
        <NameOfOtherOrganization>
          <BusinessNameLine1>MDS INSURANCE SERVICES INC</BusinessNameLine1>
        </NameOfOtherOrganization>
        <TransactionType>P</TransactionType>
        <AmountInvolved>212000</AmountInvolved>
        <MethodOfAmtDetermination>AMOUNT DUE TO MDSIS</MethodOfAmtDetermination>
      </TransactionsRelatedOrgsTable>
    </IRS990ScheduleR>
  </ReturnData>
</Return>