学习龋病学需要了解的人精品课件

DentalCaries OuyangYongAssociateprofessorDepartmentofEndodonticsandOperativeDentistrySunYat senUniversity 岳松龄王满恩史俊南刘正樊明文 李玉晶王嘉德周学东高学军凌均棨刘天佳 学习龋病学需要了解的人 史俊南 刘正 樊明文 李玉晶 周学东 凌均棨 吴补领 高学军 Introduction Photosofdentalcaries Photosofdentalcaries Photosofdentalcaries Caries isLatinfor rot or rotten Dentalcariesmeansrottenteeth CariesisthenounwhichnamesthediseaseCariousistheadjective not acaries acariousarea or anareaofcaries Dentalcariescanbedefinedas ChronicprogressivedeconstructivediseaseofharddentaltissuesBacterialinfecteddiseasescausedbyspecificbacteriaareversiblemultifactorialprocessoftoothdemineralizationandremineralization Dentalcaries Dentalcaries abacterialinfection maybedefineasaposteruptivepathologicalprocessofexternalorigin involvingthesofteningoftheharddentaltissueandproceedingtocavityformation Thisisdistinctfromthedissolutionoftheharddentaltissuesofanuneruptedtoothwhichisnotdentalcariesbuttoothresorption Thecariousprocess apathologicalprocessoflocalizeddestructionofcalcifiedtoothtissuesbyacidsproducedbyorganisms Etiologicallycariesisconsideredamulti factorialdisease whichinvolvesinterplaybetweenthehost salivaandteeth microorganisms streptococcusmutans andthesubstrate dietarycarbohydratesucrose withtheproductionofLacticacid Dentalplaque Bio film servesasthemediumforcariesdevelopment Basicpathologicalchanges demineralizationofinorganictissuesoftoothDisintegrationoftheorganictissuesoftoothinvolvesenamel dentin cementum Epidemiologyofdentalcaries流行病学 Prevalencerate 患病率 istheproportionofapopulationaffectedbyadiseaseofaconditionatonepointtime Incidence 发病率 isamesurementoftherateatwhichadiseaseprogressestheincreaseordecreaseinthenumberofnewcasesoccurringinapopulationwithinthesametimeperiod Measuringcariesactivity DMFindex DthemeannumberofdecayedteethwithuntreatedcariouslesionsMthemeannumberofteethwhichhavebeenextractedandarethereforemissingFthemeannumberoffilledteethDMF T todenotedecayed missing andfilledteethDMF S todenotedecayed missing andfilledsurfacesinpermanentteethdmf t dmf s similarindicesfortheprimarydentition Frequencydistributionofdentalcariesaccordingtovarioustoothlocation permanentdentition Deciduousdentition distributionofdentalcariesaccordingtotoothsurface Occlusal interproximal buccal Cariesisworldwideinitsdistribution TheprevalenceofdentalcariesincreaseswiththedevelopmentofeconomyHighDMFbefore1970intheindustrializedcountryTodecreaseafter1970intheindustrializedcountryMoreprevalenceinindustrializedthaninthethirdwordcountryCariesexperiencetendstoincreaseinthedevelopingcountryanddeclineinmanywesterncountries Cariesexperienceishigherinurbanthaninruralcommunitiesindevelopingcountries Prevalenceofdentalcaries 1995 specialfor12 18Yagegroupsisincreasedsignificantly 20 40 Inrecent10years prevalenceofdentalcariesinprimarydentitionisincreasedsignificantlythanthepermanent Whyhascariesprevalencedecreasedinmodernpopulation TheispossiblyattributabletoThefluoridationofdrinkingwater useoffluoridetoothpastesandimprovedoralhealthAchangingpatternofsugarconsumptionAdecreaseinvirulence 毒力 oftheorgansims Aetiologyofdentalcaries龋病的病因学 Theorganicdepositsontheenamelsurface fourfactorsisessentialfortheinitiationofdentalcaries namely Micro organismmutansstreptococciLactobacilliActinomyces SubstrateRefinedcarbohydrates 精制碳水化合物 suchassucrose蔗糖provideasuitablesubstrateonwhichthecariogenicmicro organismsacttoproducetheacidsthatleadtodissolutionoftheharddentaltissuesCariesexperienceisinfluencedbythequantity qualityandespeciallyfrequencyofconsumptionoftherefinedcarbohydrate Susceptibleteeth易感牙Theingestionoffluoridesduringtoothmineralizationleadstotheformationoffluor apatiteinenamel Itspresenceinenamelmakesthetoothlesssusceptibletodentalcariesbecauseitislesssolubleinacidthanthehydroxyapatite 羟磷灰石 whichisnormallypresentintheharddentaltissues TimeAllthefactorsshouldbepresentforsufficientlylongtimeforthecariesprocesstobeinitiated Definition Dentalplaque 牙菌斑 ClassificationofDentalplaque supragingivalplaque dentalcariessubgingivalplaque periodontaldiseases STRUCTUREOFDENTALPLAQUE PlaqueonsmoothsurfacePlaque dentalsurfaceMiddlelayer condensedmicrobiallayerbodyofplaqueThesurfacelayerofplaquePlaqueinpitandfissure CompositionofDentalplaque bacteriawhichform50 70 ofdentalplaqueasmallnumberofepithelialcellsLeukocytesMacrophagesglycoproteinswhich togetherwithextracellularpolysaccharides formtheplaquematrixmucopolysaccharides 粘多糖 suchasglucansandfructans 右旋糖 Inorganiccomponentscalciumphosphorusfluorides MECHANISMSOFPLAQUEFORMATION Theattachment growth removalandreattachmentofbacteriatothetoothsurfaceisacontinuousanddynamicprocess Severaldistinctprocessescanberecognized Absorptionofsalivaryproteinsandglycoproteins togetherwithsomebacterialmolecules tothetoothsurfacetoformaconditioningfilm theacquiredpellicle 获得性膜的形成non specificinteractionofmicrobialcellsurfaceswiththeacquiredpellicleviavanderWallsattractiveforces Irreversibleadhesioncanoccurifspecificinter molecularinteractionstakeplacebetweenadhesionsonthecellsurfaceandreceptorsintheacquiredpellicle Secondaryorlate colonizersattachtoprimarycolonizers coaggregation共集 alsobyspecificinter molecularinteractions FORMATIONANDDEVELOPMENTOFDENTALPLAQUE FormationofacquiredpellicleandprimaryaggregationBacteriagrowthanddevelopmentThematureofdentalplaque Development PellicleformationMicroorganismsdonotattachthermselvesdirectlytothemineralizedtoothsurfaceandtheteetharealwayscoveredbyanacellularproteinaceousfilm thepellicleFormsonthe naked toothsurfacewithinminutestohours SalivaryglycoproternsCarbohydratesLipidalesserextentcomponentsfromthegingivalcrevicularfluid 龈沟液 MajorconstituentsofPellicle Becauseofitsselectivenaturerestricttransportationofironsinandoutofthedentalhardtissue ItmayplayanimportantmodifyingroleincariesProvidefurtherprotectionagainstdemineralizationoftheenamelModifythenumberofpotentialadsorptionsitesfordifferentbacterialspeciesAsthesubstrateforthemicroorganisms FunctionofPellicle microbialcolonization Initialmicrobialcolonizationstreptococcusmutans 变形链球菌 accountingfor56 ofthetotalinitialmicrofloraActinomycesspp 放线菌 aminorproportiongram negativebacteria G Microbialsuccession TheinitialestablishmentofastreptococcalfloraappearstobeanecessaryantecedentforthesubsequentproliferationofotherorganismsThemoststrikingchangedisshiftfromstreptococcus dominatedplaquetoplaquedominatedbyActinomyces MICROBIALAETIOLOGYOFCARIES animalstudiesmicro organismsareinvolvedintheaetiologyofdentalcaries cariogenicmicroorganisms StreptococcusmutanslactobacillusActinomyces Cariogenicproperties 致龋菌的特性 theyareabletoproduceacidrapidlyfromfermentablecarbohydrates acidogenic Theythriveunderacidconditions aciduric abletoadheretothetoothsurfacebecauseoftheirabilitytosynthesizestickyextracelluarpolysaccharidesfromdietarysugars AdvancedlesionsoftenhaveahighproportionoflactobacillidentinallesionshaveadiversemicroflorawithmanyGrampositiveGramnegativebacteria RootsurfacecarieswasoriginallyassociatedwithActinomycesspp butrecentstudiessuggestasimilaraetiologytoenamelcariesRampantcariescanoccurinxerostomicpatientsandininfantsfedwithhighlevelsofsugarinpacifiers nursingbottlecaries Theplaquecontainshighlevelsofmutansstreptococciandlactobacilli Micro organismandcaries HypothesesandtheoryrelatingtoAetiologyofdentalcaries Chemico parasitictheory 化学细菌学说 Thispostulatesthatoralbacteriaactonsugartoproduceacidwhichdemineralizestheinorganiccomponentofenamel resultinginthedevelopmentofacariouslesion Proteolytictheory 蛋白溶解学说 Itisthoughtthattheorganiccomponentofenamelisfirstbrokendownbyproteolyticenzymes openinguppath waysforbacteriatoattacktheenamelbyotherprocessessuchasbyacidorbychelation Chelationtheory 螯合学说 ThispostulatesthatenamelisdemineralizedbychelatingagentsatneutralpH Proteinbreakdownproductsaswellaslacticacidaresomechelatingagentsknowntoexistinnature Auto immunitytheory Inthistheory itissuggestedthat forbiddenclones oflymphocytesattacktargetcells odontoblasts renderingthetoothvulnerabletocariesattack Fourfoctorstheories caries Thefourcirclediagrammaticallyrepresenttheparametersinvolvedinthecariousprocess Allfourfactorsmustbeactingconcurrently overlappingofthecircles forcariestooccur Theroleofdietarycarbohydrate Nutrition systemicdietaryeffectsDiet localdietaryeffects CariesprevalenceislowinpopulationsadheringtoaprimitivewayoflivingandadietoflocalproductswithlittlesugarAdrasticincreaseincariesisinvariablyseenwhenthesepopulation improve theirstandardoflivingandadoptamodern civilized dietwithhighsugarcontentAstrongcorrelationbetweencariesdevelopmentandsugarconsumption epidemiologicalstudies Sucrose 蔗糖 calledthearch criminalindentalcariesMonosaccharides disaccharidesandofthepolysaccharidestarchcanbefermentedtoacidbytheplaquebacteriaSorbitol 山梨糖 xylitol 木糖醇 sugarsubstitutesusedinsugar freechewing gumsDietaryhabitsandcariesprevalence Host tooth susceptibleteeth ItwasaclinicalexperiencethatnotallindividualswithpoororalhygieneandfrequentsugarconsumptiondevelopcariesInthelaboratory extractedteethexposedtothesameacidicbuff