FlexuralStrengthandFatigueofNewActiva RMGICsFGarcia-Godoy,BRMorrow*,CHPameijer

CollegeofDentistry,UTHSC,Memphis,TNandUConnSchoolofDentalMedicine,Farmington,CT

morrow.brian@hotmail.com,fgarciagodoy@gmail.com

ABSTRACTObjectives:Tomeasureflexuralstrength(FS)andfatigue(FF)ofActiva (newRMGIC)comparedtoRMGIcontrols(RMGIC),flowable composite-resins(FC)andglass-ionomercement(GI).

Methods:Rectangularsamples(2x2x25mm)weremade(ISO4049)accordingtothemanufacturers’instructions.FS(n=6/gp)andFF(n=11/gp minimum)testingwascarriedoutwithathree-pointbendingtest(0.75mm/min,100cyclesat0.03Hz,respectively).Flexuralstress,load,anddisplacementwererecordedforalltests.FSdatawerestatisticallycompared(ANOVA,SNK,P<0.05).StatisticaldataanalysisforFFwasachievedthroughtheleastfrequenteventsmethod(failuresversusnon-failures).

Results ThetablebelowshowstestresultsforFSandFF.AnalysisforFSrevealedGroups1-3werestatisticallydifferentfromGroups6-12(P<0.001).Additionally,Group4differedfromGroups5-12(P<0.025).DifferencesoccurredbetweenGroup6andallGroups(P<0.001).FatiguestatisticsdemonstratedGroups1-6werestatisticallydifferentfromGroups7-12(P<0.002).

Conclusions:AllActiva RMGICs(Groups1-3)demonstratedcomparableflexuralstrengthandfatiguetoflowablecomposites(Groups4-5)withinthepresenttestinglimits.

Table1.RoughnessData.

CONCLUSIONAllnewACTIVA™BioACTIVEProducts(Groups1-3)demonstratedcomparablemeanflexuralstrengthandmeanflexuralfatiguestressestoflow-ablecomposites(Groups4-5)withinthepresenttestinglimits.

ACKNOWLEDGEMENTS:Researchsupported inpartbythePulpdentCorporationandUTHSCCollegeofDentistryAlumniEndowmentFund.

INTRODUCTIONUnderstandingthemechanicalperformanceofvariousdentalmaterialscanhelpdetermineaspecificpatient’sneedfortreatment.Thetraditionalflow-ablecompositeresins,glassionomers,andresinmodifiedglassionomercompositeseachprovidecertainbenefitsfortreatment.ThenewACTIVA™BioACTIVEproducts deliveranewblendofadvantagesfromthetraditionalmaterialsFC,GI,andRMGIC.1

Dentalmaterialsareoftenonlyinvestigatedforflexuralstrengthorstaticperformancewithinthenormalmechanicaltesting.Although,mechanicalfatiguetestingcanrevealadditionaldataforconsideration.Therefore,flexuralfatiguewasinvestigatedinadditiontoflexuralstrengthofthesenewRMGIC’s.

Tomeasurethemechanicalcharacteristics,flexuralstrengthandflexuralfatiguewerecharacterizedandcomparedusingthemeanvalueforeachstudymaterialsimilartoISO4049.

PURPOSETheobjectiveofthisstudywastoevaluatethenewRMGIC(ACTIVA™BioACTIVEProducts;BASE/LINER™,CEMENT,andRESTORATIVE™)forflexuralstrengthandflexuralfatiguecomparedtootherRMGICcontrols,flow-ablecomposite-resins,andglass-ionomercements.

RESULTSCompleteflexuralstrengthtestingresultsarelocatedinTable1andFigure2.StatisticallyanalysisrevealedthenewRMGICsandFCs(Groups1thru5)weresignificantlydifferentandgreaterthanthecontrolRMGICsandGIs(Groups7thru12)withP<0.001.Furthermore,Geristore(Group6)wasstatisticallydifferentfromallotherstudyGroups,P<0.001.

CompleteflexuralfatiguetestingresultsarelocatedinTable1andFigure3.Statisticallyanalysisdemonstrated thenewRMGICsandFCs(Groups1thru6)weresignificantlydifferentandgreaterthanthecontrolRMGICsandGIs(Groups7thru12)withP<0.001.

MATERIALSANDMETHODSISO4049rectangularsamples(2x2x25mm)werefabricatedinpolymermoldsaccordingtothemanufacturers’instructions.Samplesofeachmaterialwerestoredindependentlyindeionizedwaterfor24hoursat37°Cbeforetesting.Seventeenormoresampleswerefabricatedforeachstudymaterial.Eachmaterialutilizedsixsamplesforflexuralstrengthandelevenormoresamplesforflexuralfatigue.Flexuralstrengthandflexuralfatiguewereevaluatedwitha three-pointbendingtestfixtureonamechanicaltestingmachine(Instron®;Norwood,MA).Flexuralstrengthwasperformedatarateof0.75mm/minuteuntilfailure.Flexuralfatiguetestingwasachievedbyusingthefrequencyoffatiguefailuresornonfailureeventswiththestaircasemethod.2Fatiguewasexecutedat1.8cycles/minute(or0.03Hz)for100cyclesuntilcompletionor failure.Flexuraldatawerecomparedusinganone-wayANOVAwithanSNKpairwisecomparisons(P<0.05).

References:1http://www.activabioactive.com/2Garcia-GodoyF,et.al.Fatiguebehavior ofdentalresincomposites:Flexuralfatigueinvitroversus6yearsinvivo.JBiomedMaterResPartB2012.

Groups - Materials Flexural Strength (MPa)

Flexural Fatigue (MPa)

Group 1: ACTIVA™ BioACTIVE-RESTORATIVE™ (RMGIC) 105.4 ± 14.3 63.7 ± 15.1Group 2: ACTIVA™ BioACTIVE-BASE/LINER™ (RMGIC) 99.8 ± 24.0 59.0 ± 4.4Group 3: ACTIVA™ BioACTIVE-CEMENT (RMGIC) 97.1 ± 15.8 59.9 ± 5.9Group 4: Tetric EvoFlow® (FC) 115.2 ± 15.4 68.4 ± 26.8Group 5: Beautifil® Flow Plus (FC) 92.8 ± 18.2 64.0 ± 11.1Group 6: Geristore® (RMGIC) 58.8 ± 12.2 45.5 ± 11.8Group 7: Fuji Filling™ LC (RMGIC) 22.2 ± 3.8 7.1 ± 1.9Group 8: Fuji Lining™ LC (RMGIC) 20.0 ± 17.6 3.5 ± 0.5Group 9: Fuji IX™ GP Extra (GI) 28.1 ± 5.0 3.1 ± 0.5Group 10: Fuji Triage® (GI) 19.7 ± 4.9 4.9 ± 3.0Group 11: Ketac™ Nano (RMGIC) 28.4 ± 10.1 6.4 ± 1.3Group 12: Vitrebond™ Plus (RMGIC) 24.0 ± 9.6 10.2 ± 11.4

Figure3. CompiledFlexuralFatiguegraphicalresults.

Figure2. CompiledFlexuralStrengthgraphicalresults.

Table1. FlexuralStrengthandFlexuralFatigueData.

Figure1. ACTIVA™BioACTIVERESTORATIVE™andBASE/LINER™.