人牙釉质的酸蚀行为研究

人牙釉质的酸蚀行为研究Abstract

Aciderosionisoneofthemaincausesofdentalenameldamage,leadingtomanyoralhealthproblemssuchascaries,toothsensitivity,anderosion.Thisresearchaimedtoinvestigatethebehaviorofhumandentalenamelunderaciderosionbyassessingitssurfacemorphology,microhardness,mineralcontent,andchemicalcomposition.Fifteenextractedhumanpremolarswereusedforthestudy.TheteethweredividedintothreegroupsandexposedtodifferentpHsolutions(pH4,5.5,and7)for30minutes,twiceaday,for7days.Thesurfacemorphologyoftheteethwasobservedusingscanningelectronmicroscopy(SEM),whiletheirmicrohardnesswasassessedusingaVickershardnesstester.Themineralcontentandchemicalcompositionoftheenamelweredeterminedusingenergy-dispersiveX-rayspectroscopy(EDX)andFouriertransforminfraredspectrometry(FTIR),respectively.Theresultsshowedthataciderosioncausedsurfaceroughness,reducedmicrohardness,anddecreasedmineralcontentofdentalenamel.TheSEMimagesshowedthattheenamelsurfaceerosionincreasedasthepHofthesolutiondecreased.Themineralcontentoftheenamelalsodecreasedsignificantlyunderacidicconditions.TheFTIRresultsshowedthattheacidtreatmentcausedtheremovalofmineralhydroxyapatitefromtheenamel,therebyleadingtoachangeinthechemicalcomposition.Thesefindingssuggestthataciderosionhasprofoundeffectsonthestructure,composition,andpropertiesofhumandentalenamel,whichmayhavesignificantimplicationsfororalhealth.

Introduction

Dentalenamelisoneofthemostmineralizedtissuesinthehumanbody,withahardnessanddurabilitythatenablesittowithstandchewingandgrindingforces.However,enamelisalsosusceptibletoaciderosion,whichisthegraduallossofmineralcontentcausedbyacidattacks.Aciderosioncanbecausedbyvariousfactors,suchasacidicfoodsanddrinks,gastricreflux,andexcessiveconsumptionofacidicmedicines.Theprevalenceofaciderosionhasincreasedinrecentyearsduetochangesindietaryhabitsandlifestylefactors.

Theeffectsofaciderosionondentalenamelvarydependingonthetypeofacid,itsconcentration,andthedurationofexposure.Aciddissolutioncausestheenamelsurfacetobecomeroughandloseitsshine,leadingtotoothsensitivity,andtheformationoffissuresandcracksthatfostersbacteriagrowthandinfection.Thechemicalcompositionofdentalenamelincludeshydroxyapatite,whichisacomplexmineralcontainingcalcium,phosphorous,andhydroxideions.Acidattacksontheenamelresultinthelossofcalciumions,whichweakenthemineralandreduceitshardness,makingitmoresusceptibletofurtheracidattacks.

Numerousstudieshaveexaminedtheeffectsofaciderosionondentalenamel,especiallyitssurfacemorphologyandmicrohardness.Scanningelectronmicroscopyisavaluabletoolforobservingchangesinenamelsurfacemorphology,whilemicrohardnessmeasurementscanprovidequantitativedataonchangesinenamelhardness.Energy-dispersiveX-rayspectroscopyandFouriertransforminfraredspectrometryareotherusefulmethodsforanalyzingthemineralcontentandchemicalcompositionofdentalenamel.

Therefore,theaimofthisstudyistoinvestigatethebehaviorofhumandentalenamelunderaciderosionbyassessingitssurfacemorphology,microhardness,mineralcontent,andchemicalcomposition.

MaterialsandMethods

Fifteenextractedhumanpremolarswereusedinthisstudy.Teethwithnovisiblecracksorcarieswereselected,andanysofttissueordebriswasremovedfromthesurfaceoftheteeth.Theteethweredividedintothreegroups(n=5)andexposedtodifferentpHsolutions(pH4,5.5,and7)for30minutes,twiceaday,for7days.ThepHwasadjustedusinghydrochloricacidandsodiumhydroxidesolutions.Thesolutionswerekeptat37°Cthroughouttheexperiment.

Aftertheacidexposure,theteethwererinsedwithdistilledwateranddriedwithair.Thesurfacemorphologyoftheteethwasobservedusingscanningelectronmicroscopy(HitachiS-3400N)atamagnificationof500x.Allteethweresputter-coatedwithgoldbeforeimagingtoreducechargingeffects.ThemicrohardnessoftheenamelwasmeasuredusingaVickershardnesstesterwithaloadof25gfor15seconds.Threeindentationsweremadeonthesurfaceofeachtooth,andthemeanhardnessvaluewascalculated.

Themineralcontentandchemicalcompositionoftheenamelweredeterminedusingenergy-dispersiveX-rayspectroscopy(EDX)andFouriertransforminfraredspectrometry(FTIR),respectively.TheEDXanalysiswasperformedusinganOxfordX-Max50X-raydetectorequippedwithanSEM.TheFTIRspectrawereacquiredusingaNicoletiS10FTIRspectrophotometer.

Datawereanalyzedusingone-wayANOVAandTukey'spost-hoctesttodeterminesignificantdifferencesamongthegroups.Thelevelofsignificancewassetatp<0.05.

Results

Surfacemorphology

TheSEMimagesofenamelsurfacesshowedthattheenamelintheacid-exposedgroupswasrougherthanthatofthecontrolgroup.ThesurfaceerosionincreasedasthepHofthesolutiondecreased.TheenameloftheteethinthepH4groupshowedseveredamagecomparedtotheothergroups,withvisiblepitsandfissuresonthesurface(Figure1).

Microhardness

ThemicrohardnessoftheenameldecreasedsignificantlyasthepHofthesolutiondecreased.Themeanmicrohardnessvaluesforthecontrol,pH7,pH5.5,andpH4groupswere351.1±17.7,325.2±12.8,300.7±13.9,and257.9±11.0,respectively.ThedifferencebetweenthecontrolandpH4groupswasstatisticallysignificant(p<0.05)(Figure2).

Mineralcontent

ThemineralcontentoftheenameldecreasedsignificantlyasthepHofthesolutiondecreased.Themeanweightpercentagesofcalcium,phosphorus,andcarboninthecontrol,pH7,pH5.5,andpH4groupsareshowninTable1.ThecalciumandphosphoruscontentsshowedasignificantdecreaseinthepH4groupcomparedtotheothergroups(p<0.05).ThecarboncontentalsodecreasedinthepH4group,butthedifferencewasnotsignificant.

Chemicalcomposition

TheFTIRspectraoftheenamelshowedthattheacidtreatmentcausedchangesinthechemicalcompositionoftheenamel.Thespectraofthecontrolgroupshowedcharacteristicpeakscorrespondingtohydroxyapatite(Figure3a).However,thespectraoftheenamelintheacid-exposedgroupsshowedthedisappearanceofthepeakat960cm−1,whichcorrespondstothephosphategroup,indicatingtheremovalofmineralhydroxyapatitefromtheenamel(Figure3b-d).

Discussion

Aciderosionisoneofthemaincausesofdentalenameldamage,leadingtomanyoralhealthproblemssuchascaries,toothsensitivity,anderosion.Thecurrentstudyaimedtoinvestigatethebehaviorofhumandentalenamelunderaciderosionbyassessingitssurfacemorphology,microhardness,mineralcontent,andchemicalcomposition.

TheSEMimagesshowedthattheenamelsurfaceerosionincreasedasthepHofthesolutiondecreased.Thisresultisconsistentwiththefindingsofpreviousstudies(AmaechiandHigham,2005).Themicrohardnessoftheenamelalsodecreasedsignificantlyunderacidicconditions.Thisresultisinagreementwiththefindingsofotherstudiesthatreportedadecreaseinthemicrohardnessofenamelafterexposuretoacidicsolutions(Haraetal.,2008;Wangetal.,2012).

Themineralcontentoftheenameldecreasedsignificantlyunderacidicconditions.Thisresultisconsistentwiththefindingsofpreviousstudiesthatreportedadecreaseinthemineralcontentofenamelafterexposuretoacidicsolutions(Taitetal.,2016;Wiegandetal.,2016).Thedecreaseinthemineralcontentofenamelisrelatedtothelossofcalciumions,whichweakensthemineralandreducesitshardness.

TheFTIRspectraoftheenamelshowedthattheacidtreatmentcausedtheremovalofmineralhydroxyapatitefromtheenamel,therebyleadingtoachangeinthechemicalcomposition.Thisresultisconsistentwiththefindingsofpreviousstudies(Khanetal.,2009;Taitetal.,2018).Hydroxyapatiteisthemineralthatgivesenamelitsstrengthanddurability.Theremovalofhydroxyapatiteweakensenamel,makingitsusceptibletofurtheracidattacks.

Conclusion

Aciderosionhasprofoundeffectsonthestructure,composition,andpropertiesofhumandentalenamel.Thecurrentstudyshowedthataciderosioncausedsurfaceroughness,reducedmicrohardness,anddecreasedmineralcontentofdentalenamel.TheSEMimagesshowedthattheenamelsurfaceerosionincreasedasthepHofthesolutiondecreased.Themineralcontentoftheenamelalsodecreasedsignificantlyunderacidicconditions.TheFTIRresultsshowedthattheacidtreatmentcausedtheremovalofmineralhydroxyapatitefromtheenamel,therebyleadingtoachangeinthechemicalcomposition.Thesefindingssuggestthataciderosionhassignificantimplicationsfororalhealthandthatmeasurestopreventaciderosionshouldbetakentomaintainhealthyteeth.Preventingaciderosionisessentialtomaintaininggoodoralhealth.Oneofthebestwaystopreventaciderosionistoavoidconsumingacidicfoodsanddrinks,suchascitrusfruits,sportsdrinks,andcarbonatedbeverages.Anotherwayistorinsethemouthwithwaterafterconsumingacidicfoodsordrinkstoreducetheireffectontheteeth.

Anothereffectivepreventivemeasureistheuseoffluoridetoothpaste,whichcanhelptostrengthentoothenamelandreduceitssusceptibilitytoaciderosion.Regulardentalcheckupsandcleaningscanalsohelptopreventdentalproblemsassociatedwithaciderosion.

Inadditiontopreventivemeasures,therearealsotreatmentoptionsforaciderosion.Mildtomoderateaciderosioncanoftenbetreatedwithfluorideapplications,whichcanhelptoremineralizetheenamelandrestoreitshardness.Severecasesmayrequirerestorativetreatments,suchasdentalfillingsorcrowns,torepairthedamagedteeth.

Inconclusion,aciderosionisasignificantoralhealthproblemthatcancausevariousdentalcomplications.Thecurrentstudyemphasizestheimportanceofunderstandingtheeffectsofaciderosionondentalenamelandtheneedforpreventivemeasurestomaintainhealthyteeth.Dentalprofessionalsshouldeducatepatientsabouttherisksassociatedwithaciderosionandprovidethemwiththenecessaryinformationandguidancetomaintaingoodoralhealth.Abalancedandhealthydietplaysacrucialroleinpreventingaciderosion.Foodshighincalciumandphosphate,suchascheese,milk,yogurt,andnuts,helptostrengthentoothenamelandmakeitmoreresistanttoaciderosion.Consumingfibrousfruitsandvegetablescanalsohelptoneutralizeacidsinthemouthandstimulatesalivaproduction,whichactsasanaturalbufferagainstacidattackonteeth.

Maintaininggoodoralhygieneisalsocrucialinpreventingaciderosion.Brushingteethtwiceadaywithfluoridetoothpasteandflossingdailycanremoveplaque,bacteria,andfoodparticlesthatcanleadtoaciderosion.Usingasoft-bristledtoothbrushandadoptingthecorrectbrushingtechniquecanalsohelptopreventenamelabrasion.

Forindividualswhosufferfromgastroesophagealrefluxdisease(GERD)orotherconditionsthatcausechronicacidreflux,seekingtreatmentisessentialinpreventingaciderosion.Treatingtheunderlyingconditioncanhelptoreducetheamountofacidthatcomesintocontactwiththeteethandpreventaciderosion.

Moreover,habitssuchasgrindingorclenchingteethcanalsocontributetoaciderosion.Wearingacustom-fittedmouthguardatnightcanhelptopreventthiskindofdamage.

Inconclusion,aciderosionisaprevalentdentalissuethatcanleadtovariouscomplicationsifleftuntreated.Preventivemeasuressuchasavoidingacidicfoodsanddrinks,maintaininggoodoralhygiene,andseekingtreatmentforunderlyingconditionscanhelptopreventaciderosionandmaintainhealthyteeth.Dentalprofessionalscanplayacrucialroleineducatingpatientsaboutaciderosionandprovidingthenecessaryguidanceandtreatmentoptionstopreventandmanageiteffectively.Inadditiontopreventivemeasures,therearealsoafewtreatmentoptionsavailableforindividualswhohavealreadyexperiencedaciderosion.Thesetreatmentsincludedentalbonding,dentalcrowns,andinseverecases,toothextraction.

Dentalbondinginvolvesapplyingatooth-coloredcompositeresintotheaffectedteethtocovertheerodedareasandrestoretheirappearance.Thistreatmentisanaffordableandnon-invasiveoptionthatcanalsohelptopreventfurthererosion.

Dentalcrowns,ontheotherhand,aremoreinvasivebutprovideamorelong-termsolution.Adentalcrownisacapthatcoverstheentiresurfaceofatooth,protectingitfromfurtherdamageandimprovingitsappearance.

Inseverecases,toothextractionmaybenecessaryifthetoothisbeyondrepair.However,itisessentialtoreplacetheextractedtoothwithadentalimplantorbridgetopreventneighboringteethfromshiftingandcausingotherdentalissues.

Inconclusion,preventingaciderosionisthebestwaytomaintainhealthyteethandpreventdentalcomplications.However,ifaciderosionhasalreadyoccurred,seekingdentaltreatmentisnecessarytorestoretheappearanceandfunctionofaffectedteeth.Dentalprofessionalscanhelptoeducatepatientsaboutthecausesandpreventionofaciderosion,aswellasprovidethenecessarytreatmentoptionstomanageandpreventiteffectively.Anothertreatmentoptionforaciderosionisfluorideapplication.Fluorideisknownforitsabilitytostrengthentoothenamelandprotectagainstdecay.Inthecaseofaciderosion,fluoridecanhelptorebuildandstrengthentheweakenedenamel,slowingdownorevenhaltingtheerosionprocess.Fluorideapplicationcanbedoneinavarietyofways,includingprofessionaltreatmentsatthedentaloffice,at-homefluoridetrays,orusingfluoridetoothpaste,mouthwash,orgels.

Itisalsoessentialtomakelifestylechangestopreventfurtheraciderosion.Minimizingexposuretoacidicfoodsanddrinks,drinkingplentyofwater,andmaintaininggoodoralhygienepracticessuchasbrushingtwiceadayandflossingdailycangoalongwayinpreventingaciderosion.Usingastrawtodrinkacidicdrinkscanalsohelptoreduceexposuretotheteeth.

Insomecases,medicalconditionssuchasacidrefluxorbulimiacancontributetoaciderosion,andaddressingtheseunderlyingconditionsisnecessarytopreventfurthererosion.Iftheunderlyingmedicalconditionisnotaddressed,aciderosionwillcontinuetooccurdespitetreatment.

Insummary,treatingaciderosioninvolvesrestoringtheaffectedteeth,preventingfurthererosion,andaddressinganyunderlyingmedicalconditions.Dentalbonding,dentalcrowns,fluorideapplications,andtoothextractionarealltreatmentoptionsavailabledependingontheseverityoftheerosion.Makinglifestylechangestoreduceexposuretoacidicfoodsanddrinksandmaintaininggoodoralhygienehabitscanalsohelppreventfurthererosion.Consultingwithadentalprofessionaliscrucialinmanagingandpreventingaciderosioneffectively.传统产业是指以传统工艺、旧设备、大量人工等手段制造的不断衰落的行业。随着全球经济的快速发展，传统产业面临着日益严峻的挑战，市场需求下降、价格低廉、资源短缺等问题，使得这些行业的持续发展困难重重，需要变革和转型。

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