� �

CONTENTS 2 Preface

3 CourseSchedule

4 CourseSurvivalTips 6 InlayCavityPreparationforPosteriorTeeth RichardV.Tucker,DDS 9 ImpressionTechnique

�0 Temporaries

�� LaboratoryNotesforCastGoldRestorations RichardV.Tucker,DDS

�4 ATechniqueforFinishingGoldCastings RichardV.Tucker,DDS

�6 ConservativeCastGoldRestorations RichardV.Tucker,DDS DennisM.Miya,DDS

4� AllAboutPinsinGoldCastings RichardD.Tucker,DDS RichardV.Tucker,DDS

44 CastGoldClinicalInstrumentandSupplyList RichardV.Tucker,DDS

46 LaboratoryInstrumentsandSupplies RichardV.Tucker,DDS

47 Suppliers

48 EducationalMaterials

49 Map

50 RubberDamPlacement DennisM.Miya,DDS

PREFACE

A fewyears ago,DickTucker and Iwere having lunch at the

MeanyHotelandwetalkedaboutcreatingaclinicalcoursein

Seattlewheredentistscouldlearnaboutconservativegoldcast-

ings.Thereseemedtobeaneedforsuchacoursesincetheonly

wayadentistcouldlearnagoodtechniqueatthattimewasthrough

participation in a study club. Dick had taught a five day clinical course for many years at the

UniversityofBritishColumbia.Theidealscenariowouldbetoprovidecoursesfordentistsand

laboratorytechniciansinaprivateteachingfacility.Hence,theconceptoftheTuckerInstitute

wasconceived.

Thereisnoprivatefacilityyet,butthiscourseandotherslikeit,marksthebeginningof

ourjourney.Ihopethattheinformationinthissyllabusandyourexperienceinthecoursewillbe

ofassistanceforyourjourneytowardperfectionandenjoymentofgoldcastings.

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CourseSurvivalTips

PreparationYouarecomingtolearnRichardV.Tucker’stechniqueforgoldrestorations.Youputyourselfatadisadvantageifyoudonothavealloftheexactinstrumentsandsuppliesthatarelistedforthetechnique.Youwillspendprecioustimeborrowingitemsfromyourfellowstudents.Oryoumightsubstituteinstrumentsorsuppliesthatdon’tworkaswellforthetechnique.Basedonourexperiencefrompreviouscourses,ablindfaithapproachseemstoworkthebest.

IfyouchosetomaximizeyourexperiencewithDr.Tucker,Iwouldrecommendthefollowingpreparation:readthesyllabus;watchDr.Tucker’sDVDwiththeThe Gold Inlay,Varia-tions in Cavity Design,andThe Laboratory:getthemodelsofDr.Tucker’spreparationsandthenpracticecuttingpreparationsonivoreenteeth,tryingtoduplicatethemodelsexactlyasfarasoutlineform,proportionandpreciseness.

TreatmentPlanningCreateasituationwhereyouhavethebestchanceofhavingapositivelearningexperience.Chooseapatientthatiseasytoworkon.Chooseteeththatareidealfortherestorationsthatyouwanttolearnhowtodo.Teethwithincipientlesionsorsmallrestorationsareideal.Trytostayawayfromteethwithlargerestorations,poorqualitytoothstructure,potentialcariousexposures,andteethwithaccessproblems.Itisbettertotakeyourtimeanddoonerestorationwellratherthanmultiplerestoresatamediocrelevel.

StudyClubFormatWhen someone is finished with his preparation or seat, the mentor will ask for permission to an-nouncethattheprocedurehasbeencompleted.Allparticipantsofthegroupcanthenlookatthecompletedprocedure.Youcanlearnalotfromobservingwhatothershavedone.Itisalsoaformofsupportforyourfellowparticipantstotakethetimetolookattheirprocedure.

MasteryInabookcalledMastery, GeorgeLeonardtalksaboutsucceedingatanytask.Hesaysthatmas-teryisnotperfection,butratherajourney,andthetruemastermustbewillingtotryandfailandtryagain.PerhapssomeofhisthoughtsonmasterywillassistyouonyourjourneytowardbecomingaMasterDentist.

TheFiveMasterKeys:�. Instruction2. Practice3. Surrender4. Intentionality5. TheEdge

55 5

•InstructionFindtherightteacher.“Whyre-inventthewheel?”Beginwithagoodfoundation.Lookforthosewhothemselveshavehadgreatteachers.Lookforpatientsandempathy.Lookforthosewhointeract,whopraiseatleastasmuchastheycritique.•PracticePracticecanbeusedasaverb.WepracticetogettoCarnegieHall.Forthemaster’sjourney,prac-ticeisnotsomethingyoudobutsomethingyouare.Practiceisthepathuponwhichyoutravel.Apractice(asanoun)canbeanythingyoupracticeonaregularbasisasanintegralpartofyourlife-nottogainsomethingelse,butforitsownsake.•SurrenderThecourageofamasterismeasuredbyhisorherwillingnesstosurrender.Thismeanssurrendertoyourteacherandtothedemandsofyourdiscipline.Perhapsthebestyoucanhopeforonthemas-ter’sjourneyistocultivatethemindandheartofthebeginningateverystagealongtheway.Forthemaster,surrendermeanstherearenoexperts.Thereareonlylearners.•IntentionalityApplyfullconsciousnesstoanactivity,don’tjustgothroughthemotions.•TheEdgeA master is one who not only pursues the refinements of a skill; he eventually pushes the edge of the envelope.

77

InlayCavityPreparationforPosteriorTeethRichardV.Tucker,D.D.S.

Thestepsrequiredintheplacementofacastgoldrestorationareasfollows:diagnosis,toothpreparation, impressions, models, wax up, investing, casting, cementation and finishing. A flaw in any of these steps or lack of attention to the finest detail would result in failure or an unsatisfactory result. Thesinglestepwhichcontributestoalargenumberoffailures,andthatwhichrequiresaspecialeffortfromtheoperatingdentististhecavitypreparation..Awellpreparedcavitynotonlymeetsthestandardcriteriaofasatisfactoryoutlineform,resistanceform,retentionformandtheotherrequirementsestablishedyearsagobyG.V.Black,italsomustbesmoothandpreciseinbothitsinternalandexternalform.Itisthisprecise,smooth,properlytaperedcavitywithsharpmarginsandinternalanglesthatmakeitpossibletocarryouteachoftheotherstepswithprecision2. Considerthesestepsmentionedaboveinrelationtothecavitypreparation.Theproperdiagnosisandtreatmentplanisoflittlevalueifthetreatmentisnotadequatelycarriedoutwhilepreparingthetooth.Thepreparationshouldencompassthatwhichwasconsideredwhenitwasdeterminedthatthecastgoldrestorationwasindicated.Itinvolvesocclusalcoverage,estheticconsiderationsandpreven-tiveconcepts. Agoodimpressionismoreeasilyobtainedifthecavityissmoothandsharp,andwithoutthissharpness it is difficult to evaluate the impression. The models are enhanced also by the fine definition ofagoodcavityandfewerfragileareasresult.Asatisfactorywaxpatternismoreeasilyobtainedfromthe model of a smooth cavity preparation with a proper taper and well defined margins. As a result the casting, which can be no better than the wax pattern, is likely to have fewer flaws and discrepancies thanifthepreparationofthetoothwereroughandirregular. Thelastconsiderationwouldbethataproperlyextendedcavitywithsharpsmoothmarginsmake it possible to finish the restoration on the tooth and to produce a more perfectly adapted gold inlay. Dr.GeorgeEllsperman, an outstanding teacher and critic of operative dentistry,invariablyspeaks of his concern with cavity detail, cavity design and fine margins3.Consideringtheimportanceascribedtothecavitypreparation,whichisthethemeofthispaper,ashortdiscussionofthesometimesmundanesubjectofcavityinstrumentationwillbepresented.ThefollowingstepsinprocedurewillinvolvetheposteriorClassIIcavity.

�.Therubberdamshouldbeplacedtogivevisibility,tissueretraction,andforeaseof operation.Whenitisapparentthatsomeprocedurecanbedonebetterwiththedamremoved,suchasdiscingofamarginonthedistalsurfaceofthemostposteriortooth,thenthepreparationshouldbecompletedas nearly as possible before removing the dam for final completion.

2.Thetoothopenedwithahighspeeddiamondstonetheneithera#56carbideburforabicuspidtoothora#57carbideburforamolarwouldbesubstituted.Careisusedtoavoidovercutting.Theflat occlusal and gingival walls are placed at the same time as establishing the axial wall and the oc-clusalpulpalwall.Theroughedoutcavo-surfacemarginiscutatthesametime.Allofthisisdonewhilemaintainingaslighttaperawayfortheocclusalsurface.

3.Thedoubleendedoffanglechisel#42S(�5-�0-�6)isusedtoplanethedistalbuccalwallwiththeoneblade,thendownthedistallingualwallwiththeother,whilemaintainingaslightdivergencetoallowfordrawofthewaxpattern.ThesameinstrumentoftheFerrierenamelhatchet#�5and#�6

77 7

(�5-8-�4)isthenplacedontheedgeoftheocclusalwallandwithtwoorthreeslicestowardthegin-gival,theaxialwallisplaned.Thechiselmeetstheproximalwallstoestablishthebucco-axialandthelinguo-axiallineangles.Thebucco-gingivalandlinguo-gingivallineanglesarecoincidentallyformed by the chisel chopping to the gingival wall. The 42S chisel also should smooth any flaws or discrepanciesontheocclusalwallandgingivalwallwhileitisinhand.Thesameprocedureisusedonthemesialareasofthetoothwiththeoffanglechisel#43S(�5-�0-�6)andortheenamelhatchet#15 or #16. On both the mesial and distal areas of the tooth, the proximal walls should be planed first sotheeffectofgougingthelineangleswiththeedgeofthechiselwouldberemovedastheaxialwallisplanedalongthisangle.

4.Thegingivalmarginsarebeveledwithdoubleendedmarginaltrimmers#232(�0-95-�9-�6)forthedistal;then#233(�0-80-�0-�6)forthemesialareasofthetooth.Thedoubleendedinstrumentswouldbeusedforeaseofoperation.Themarginaltrimmersshouldbesharpenedtoacuteanglessothebevelonthegingivalmarginswillbelongerthanthatwhichwouldbeproducedwiththemoreflattened marginal trimmers. The gingival bevel should be made smooth and even with the trimmers planingtowardtheproximalwalls.

5.Thereissomedifferenceofopinionregardingtheuseofabevelontheocclusalmargins4.Whenthetoothbeingpreparedisverysound,withocclusalenamelthat hasnotbeenbruisedorcrazed,itmay be justifiedthat just a faint contouring should be done with a medium sand disc. There would be lessconcernoffuturebreakdownoftheocclusalmarginhowever,ifabevelofapproximatelytwentydegreeswereplacedwitha#56carbidebur.Thediscdoesservetopolishtheproximalwallsiftheyhavenotbeenplanedsharpandstraightwithchisels.

6.Whenitisnecessarytocoveracusporcuspswithgolditcanbeaccomplishedeffectively with a #7404 or #7406 twelve fluted bur producing a hollow ground relief and bevel. This finishing bur is used in almost a painting motion to establish a smooth, well defined flowing outline totheextendedcavity5.Thistechniquewouldnotbeusedforcoverageofmaxillarybuccalcuspsasitwoulddisplayanunnecessaryamountofgoldandtheinclinedplanesoftheoccludingteethdonotrequiresuchcoverage.Insuchcasesafterocclusalreductionhasbeendonewiththehollowgrindingbur,onlyasleightdiscingisnecessarytoremovetheacutenessofthemargin.

Ithasbeendemonstratedthatthereisarelationshipbetweensurfaceroughnessofthecavityorthecastingandconsequentretention6.Itwouldseemunreasonabletoapplythisfacttoposteriorinlayswhichpresentlittleornoretentiveproblems.

99

However,itshouldgivecausetoavoidpolishingwithdiscsthebulkofthreequartercrownorfullcrownpreparations.Ithasbeenshownthatproperlyplacedpinsservewelltoincreasetheretentivequalityofacasting.Ifatoothisdestroyedtotheextentthatretentionshouldbeaproblemtheplace-mentofthepinsisthesimplesolution. In view of the fundamental necessity to prepare a fine cavity to accomplish a satisfactory gold in-lay,itishopedthatthispaperandthetechniquethathasbeendescribedwillbeofsomeassistance.

References�.Brown,MiltonH.,ImpressionProceduresforRestorativeDentistry.Dental ClinicsofNorthAmerica,Philadelphia,W.B.SaundersCo.,�967,p.�49.

2.Bassett,IngrahamandKoser,AnAtlasofCastGoldProcedures,Uni-tro CollegePress,BuenaPark,Califronia,p.�4.3.Ellsperman,GeorgeE.,Bellingham,Washinton,PersonalConsultation.4.Frates,F..E.,Inlays,DentalClinicsofNorthAmerica,Philadelphia,W.B. SaundersCo.,�967,p.�63.

5.Tucker,R.V.,VariationofInlayCavityDesign,JADA84:March�972,p. 6�6.

6.Charbaneau,G.T.,SomeEffectsofCaityRoughnessOnAdaptationofGold Castings.J.DentRes.37:95Feb.�958.

7.Lore,R.E.andMyers,G.E.,RetentiveQualitiesofBridgeRetainers, JADA76:p.57�March�968.

99 9

ImpressionTechnique�.Foroneortwocrownsorperhapsaquadrantofinlays,thequadrantcheckbiteisaproventech-

nique.2.ThemetalCoetrayisusedmostoften.WhenthebackoftheCoetraydoesnotallowthepatienttobiteintocentricocclusioncomfortably,thesmallerwireEmerytrayisused.3. Forgingivalretraction,abulky,non-braidedcord(Gingivi-Pak#3,Surgident)ispre ferred.Thiscordprovidesgoodretractiondepthbelowthepreparationandgoodwidth of the sulcus. The popular braided cord, double pack method where the first chord remainsinthesulcusduringtheimpressiongenerallydoesnotprovidethedepthand widthdesiredforgoodimpressions.Invariablythetissueseemstobleedifbothchords areremoved.A25%aluminumchloridesolution(Hemodent)isusedforhemorrhage control. It seems to be kind to the tissue and leaves no film on the preparation. Ferric sulfate is notrecommendedforahemostaticagentforinlaypreparations.4.Oneortwocordsareplacedaroundthepreparation.Twocordsseemtoworkwell interproximally.Theyshouldbeleftinplaceforabout3–4minutes.Priortotakingthe impression, check the fit of the tray and have the patient practice getting the “feel” of bitingintocentricocclusionwiththetrayinplace.Notetheocclusiononthe contralateralsideasaguidesoyouknowwhenthepatientisbitingintocentric occlusion.5.Lightbodypolyvinylsiloxaneimpressionmaterialisusedfortheentireimpressiontoavoid foldsthatcanoccurattheinterfaceoflightandheavybodymixes.Thepotentialsetinhibitionduetotherubberdamorlatexglovescanbecounteractedbycleaningthepreparationandadjacentteethwithacottonpelletsaturatedwithdilutedhydrogenperoxide,followedby athoroughrinse.Hydrogengasevolutionisaby-productofthepolymerizationofpolyvinyl siloxaneimpressionmaterials.Smallvoidsinthestonemodelwillresultiftheimpressionispouredtoosoon.Modelpourupsshouldbedelayed30minutesto2hoursdependingonthebrandofmaterial.6. Before the impression material is mixed, the operating field should be spray washed and driedandthecordisslowlyremoved.Itischeckedforadequateretractionandthatthereisnohemorrhage.Ifretractionisnotadequateorifthereishemorrhage,repack.Ifitissatisfactory,itmustbemaintaineddryandtheimpressionmaterialismixed.Syringeimpressionmaterialintothepreparation,placethecheckbitetrayandhavethepatientbiteintocentricocclusion.Bepreparedto“assist”thepatientintotheproperjawpositionwithgentlepressureonthechin.Continuetomonitorandsupportthepatientforafewminutestomakesurethatthereisnodistortionintheimpressionduetopatientmovement.7.Checkthesetofthematerialwiththetipofthecottonpliers.Whenthematerialseemstobeset,

allowonemoreminuteofsettime.8.Removetheimpressionwithafastmovementinaverticaldirectiontominimizedistortionandtearing.9.Ifthereisaquestionthatthepatientwasbitingincentricocclusion,asupplementalbiteofBlu-

Moussematerialcanbetaken.Anewimpressionisgenerallynotnecessary.

����

DuraSealTemporaryArmamentarium

DuraSealacrylicTemporarystopping(guttapercha)LargestraightbrushWoodsenhandinstrument2dappendisheslighter (flame)

IndicationDuraSealisasemi-softacrylicthatisidealforinlaysandonlays.Itiseasyandquicktoplaceandtoremove.

�.Apieceoftemporarystoppinglargeenoughtocoverthegingival2/3ofeachboxformisheatedwithalighterandtakentoplacewithaWoodseninstrument(packer/pluggercombination).Itactslikeadamsothattheacrylicdoesnottouchthetissuesothestoppingmustbeplacedagainsttheadjacenttoothaswell.

2.Thestoppingshouldnotextendabovethecontactstoallowtheacrylictobe“lockedin”atthecontactsoftheadjacentteeth.Excessstoppingcanbecontouredandremovedwithaheatedinstrument.

3.TheDuraSealacrylicisplacedwiththeliquid/powdermethodusingafairlylargebrush.Buildacrylictocontour,besuretocoverallmarginsofthepreparation.Workquicklybecausethepatientmustbiteandgothroughexcursivemovementswhiletheacrylicisstillfairlysoft.Theacrylic can be molded with moistened finger-tips. No attempt is made to refine the occlusion if it is not grossly excessive. Excess flash can be

removedwithacleoidoraheatedinstrument.4.Multiplepreparationscanbeconnectedwithasinglelayerofacrylic.5. Tell the patient they will not be able to floss.6.Therearemoresophisticatedmethodstotemporizeinlaysandonlaysbutthismethodisveryeasy

andfastbothduringplacementandremovalsincenotemporarycementisused.Patientsseemtotoleratethistemporarywell.Thegingivaltissueresponseisgenerallysurprisinglygood.

���� ��

LaboratoryNotesForCastGoldRestorationsRichardV.Tucker,D.D.S.ImpressionPour-up

�. Rinseandcleanimpressionwithroomtemperaturewater.2. Spraytheimpressionwithsurfactant.3. Pourtheimpressionimmediately.4. Useadiematerialwithminimumexpansion.FujiRock(goldenbrown).5. Weighthediematerialandmeasurethedistilledwatertomanufacturer’s specifications. Proportion of 20 ml water/100 g of stone.6. Lineupthepinssodiescanbewithdrawn.

Articulating�. Pourtheopposingcast.2. Cutkeywayoneachsideofdowelpins.3. Paintarounddowelpinswithseparatingmedium.4. Fitimpressiontoarticulator.5. Pour�/2atatime.6. Removeimpressionfromthecasts.7. Immediatelypouraback-updie.8. Allow the die material to set at least five hours.

Dies�. Separatedieswithcopingsawandthinblade.Treatdiesverycarefully.2.Trimdieswithsharpknivesandchisel,notwithabur.3. Donotusecyanoacrylate(superglue)onthedies.4. Donotwetorwashdies.5. Donotsoakdiesinlubricant.

Waxing�. Brushonwaxseparatorsparingly.(NeyDieLube)2. Paintopposingandadjacentteethwithdielube.3. Apply wax (Yeti grey) evenly, flowing into all line and point angles.4. Flowwaxwithsweepingmotionovertheentiresurfaceofthediebeforeallowingitto

hardeninordertoavoidlinesandvoidsinthepattern.5. Buildwaxtoexcess.6. Establishcontacts.7. Meltocclusionwithhotspatulaandclosearticulatortoregisterbite.8. Carve and finish the wax pattern immediately after the wax is built up.9. Avoidscrapingthediemarginswithcarvinginstruments.�0.Avoidreapplyingwaxoveraoncecarvedmargin.��.Besurewaxiscoolbeforeremovingwaxpattern(mayrefrigerate).�2.Avoidrepeatedremovalofwaxpattern.

�3�3

Howtosprue�. Spruepatternonthedie.2. Using#�2shapes,cutapproximately�/8in.longblindspruesandattachtoallgingivalmar-

gins.3. Placemainsprueonheaviestpart.4. Oncontactoppositemainsprue,place�/8in.waxsprue.Runawaxspruefrombasetothis

sprue.5. Donotdistortwaxpatternonremoval.6. Applysurfacetensionremover.(WaxIt)

Investing �. Investimmediately.Donotallowittosetonthesprueformer.2. Linetheringwithasbestosorasbestossubstitute.3. Allowafewmillimetersoftheendoftheringtobefreeofliner.4. Soakringinwaterandshakeoffexcess.5. Useroomtemperaturedistilledwaterwithinvestment.6. Measurebothwaterandpowderaccurately.7. Spatulate�0secondsforathickmixand20secondsforathinmix.8. Usevacuuminvestor.NovocastInvestment(WhipMix)50gramsofpowder.Nowater

bath.Paintinvestmentonthepattern.Fillthering.

Water/Powder(cc)Temperature˚FRingLinerCrown �5.5 ��75 23/4,7/8Cr �8 ��50 2MODBL �8 ��50 2MOD �8.5 ��50 2DO,MO,Occ �5 ��75 2BurnOut

�. Allowtheinvestmenttosetatleast�hour.2. Carveoffendofinvestmentinthering.3. Placeincoolfurnace.4. Besurefurnaceiscalibrated.5. Runfurnacetotemperature,heatrateat3takesabout�hour.

Casting�. Castwithin20minutes.2. Use air and gas flame ( no oxygen).3. Do not over heat gold. Dust with flux, cast as soon as the gold rolls together.4. Kerrbrokenarmcastingmachineisgood.5. UseaTypeIIgoldwithBrinellhardnessof95-��0withapproximately80%goldalloy.6. Letgoldcoolinringbeforebreakingout.7. Brushcastingcleanandplaceinanultrasoniccleaner.Donottouchinsidewithaninstru-

ment.8. Boilinreducingsolution(Prevox).

�3�3 �3

Finishing�. Cutcastingoffspruewithseparatingdisc.2. Trycastingondiecarefullycheckingforopenmarginsandproperexpansion.3. Keepalogofeachcastingwithvariablesnoted.e.g.water/powderratio,castingtem-

perature,andtimeoffurnacetemperaturebuild-up.4. Adjustcontactsandbite.5. Adjustcontactwithrubberwheel.6. Finish casting with #.5 round bur over all occlusal fissures.7. UseRobertson#��standardstiffbristlebrushwithTripolioverocclusalalsoendbrush

mandrelsthathavebeensharpened.8. All other surfaces are finished with discs in the following order: medium garnet, fine sand

and fine cuttle.9. Robertsonsoftbristlebrushwithrougeovertheocclusal.�0.FeltwheelonmandrelwithTripoli.��.Chamoiswheelonmandrelwithrouge.DonotletTripoligetonchamois.�2.Washpolishoffcastingwithhotwaterandallpurposecleaner. (Mayuseultrasonic).�3.*Note:Whilewaxing,removeasmuchbulkfromtheinsideaspossiblewithasharp

cleoidordiscoidinstrument.�4.*Note: Do not finish on the die, and avoid finishing the margins.

�5�5

ATechniqueForFinishingGoldCastingsRichardV.Tucker,D.D.S.

Afterallproceduresnecessarytoproduceagoldinlay,onlay,orothertypeofcastinghavebeencompleted with care and understanding; the last step, the finishing of the gold if done properly will make the difference between a serviceable restoration and that of a fine, beautiful case. The procedures described below are predicated on the fact that the casting fits the tooth cavity, because without a good casting no finishing technique will produce a fine case, nor even a serviceable restoration. The initial procedure of finishing involves the laboratory, as it is here that the difficult access areas on the occlusal portion of the restoration are refined and polished; and the final contours are placed onthecastingToavoiddestructionofthedetailedanatomyinthecasting,thefollowingproceduresaresuggested.Allaccessiblesurfaces,exceptcontactareasandmarginsaresmoothedwith�/2inchgarnet medium, and 1/2 inch sand fine discs in that order. Then 1/2 inch cuttle fine discs are used over allsurfacesofthecasting,includingmarginsandinterproximalcontactpoints.. All pits and fissures are smoothed lightly with a No. 3 carbide bur, contacts corrected, occlusion corrected,thenallocclusalanatomyispolishedwithaNo.��standardstiffbrushwheelandtripoli.Ifneededtheendbrushmandrelmaybeusedwithtripoliinthedeepareasofthecasting.Finallytheno.��softbrushwheelisusedwithahighpolishingcompoundoverallsurfacesofthecasting. Since the restoration is finished except for the margins before cementation, the dentist confines hiseffortsintheoperatorytothemarginsonly. Followingtheadministrationofananestheticandproperisolationwiththerubberdam,thecavityiscleanedandthencavityvarnishisappliedtothedentinwalls,usingcarenottoapplyitonthemargins.Therestorationis“tried”toinsurepropercontact.Itisnotnecessarytodrivetherestorationtoplacepriortocementation.Usuallyitcanbeleftahalfmillimeterfrombeingcompletelyseated,wecanbesureofproperexpansionofthecasting,doanynecessaryadjustmentofthecontactpoint,andavoid the difficult task of removing a hard seating casting that could damage the tooth or the restoration. Aslowsettingmixofzincphosphatecementshouldbemadeonacoolglassslab.Thisisaccomplishedbyslowintroductionofthepowdertotheliquidandpowderwouldbeaddedonlytothepointthatitwoulddropfreelyfromthespatula.Thisisimportantasthecastingwouldnothavebeenfinished on the tooth prior to this time and the margins should be smoothed with the most coarse of the threediscs,priortothehardeningofthecement. The interior surfaces of the casting are first covered with cement which would also be applied tothecavityinthetooth.Afterhavingplacedthecastinginthetoothitwouldbeseatedhardbyapply-ingconsiderablepressureonanorangewoodstickwhilebeinggentlymallotted.Thecastingshouldbeheldwithpressureforashortperiodoftimetoallowreleaseofhydraulicpressure,whichcouldcausethecastingtolift. Withaslowlyrotatingmandrelinastraighthandpiece,amediumgritgarnetdiscshouldberolledoverthemarginsfromthecastingtowardthetoothsurface,creatingasingleplanebetweenthegoldandthetooth.Thisalsoaccomplishesaslightburnishingofthegoldatthemargin. Allmarginsofthegoldcanbeoperatedwiththestraighthandpieceexceptthemesio-lingualmarginandthegingivalmarginsofallposteriorteethinboththemandibleandthemax-illa,withsomeunusualexception.Afterallothermarginshavebeensmoothedwiththistypedisconthestraighthandpiece,thecontra-anglewouldbeusedtosmooththemesio-lingualaspect.Thisisaccomplishedwiththegritsideofthedisc“in”facingthehandpiece.Finishingtothispointshouldbedonebeforethecementhashardened.

�5�5 �5

Thenextprocedurerequireslittletimebecauseitismerelytopolishthegoldandthetoothatthe margins, not reduce them. The 1/2 inch fine sand grit disc would be used with the same handpiece proceduresasdiscussedabovetoaccomplishareductioninthesizeofscratchesleftbythemediumgarnetdiscs. Attention is next given to the gingival margins. The casting should fit accurately, with no excess gold over the margin. A narrow eighteen inch finishing strip, with medium garnet grit, sharpened to allow passage, would be passed interproximally. This is aided, as is the entire finishing of the gingival margins,bytheassistantretractingthetissueastheinterproximalrubberdamisheldup,onboththebuccalandlingualaspects.AlittleVaselinelubricantalsoisanaidtoavoidcatchingtherubberwiththestripasitispassedoverthemargins. Theuseofthestripsmoothesthegingivalgoldandtoothstructuretothesameplane,aswellasthegingivalthirdofthebuccalandlingualcavosurfacemargins,whichcannotbereachedwithdiscs.Usuallytwoorthreeswipesoverthemarginaccomplishesthispurpose,andcareshouldbegiventoavoidoveruseofthestripontherelativelysoftcementum.Itisobservedthatifgoldisinexcess,itseldom can be finished properly to the tooth, since the strip seems to remove tooth structure faster than thegold. After use of the medium garnet strip, a similar fine cuttle strip is use in the same manner. Again only two or three passes with the strip should suffice. This is only to remove fine scratchesandpolishwhereitisnotpossibletouseadisc. If there are inaccessible areas such as in grooves or fissures, a fine white stone may be used in those specific areas of the tooth. A fine cuttle disc is then used to polish all accessible margins in the manner described above. Thisseemstoclosethejointaswellaspolishthesurfaces. Finalpolishingcanbedone,aftertheproperdiscingwithverylittleeffort.Firstaslurryofpumice in a rubber cup on a contra-angle would be used, to be followed by flushing and irrigation. After drying the field of operation, dry tin oxide or similar polishing agent would be lightly used over allaccessiblesurfaces. Itshouldbenotedthataircoolantbeusedduringalldiscingandduringuseofthestrip,aswellaspolishing,toavoidover-heatingthetooth.

�7�7

Introduction

ConservativeCastGoldRestorationsRichardV.Tucker,DDSDennisM.Miya,DDS

Historically,theuseofgoldforrestora-tionsindentistryhasdeclinedwiththedevelop-mentofcompositeandporcelainrestorations.However,conservativecastgoldrestorationscontinuetobethetreatmentofchoicetorestoreposteriorteethanddistalofcuspidsformanyclinicians(Fig�).Theprimaryadvantageofagoldcastingisitspermanence(Fig2).Thistypeofrestorationcanlastalifetime.Acast-goldres-torationmaintainsthebeautyofanaturaltoothinmostcaseswhencavitydesignisthoughtfullyconsidered,andwhencareisgiventoperfectionof the casting and its finishing. Typical cast gold restorationsareshowninFigs3ato3f.Theadvantagesofgoldcastingsare:

�. Goldalloysdonotoxidizeanddis-colortheteeth.

2. Fragileareasofteethcanbeprotect-edbycoveringthemwithathinlayerofgold.

3. Thegoldrestorationitselfwillnotfractureintheisthmusorotherareas.

4. Themarginsofthetoothandgoldarenearlyimperceptibleifhandledproperly.Thisisnotsolikelytohar-borplaqueandconsequentlyshouldcontributetobettertissuehealth.

5. The cast gold inlay can be finished to beahighlypolishedandsmoothsur-face,whichispleasanttothetongueandcompatiblewiththeoraltissues.Thisalsoismoreplaqueresistantthanamoreroughenedsurface.

6. Goldcastingssuchas3/4,7/8orfullcrownscanbindthetoothtogethertopreventfractureorrelievesensitivitywhentinyfracturesarepresent.

7. Thedentalanatomycanbemore

nearlyreproducedwithacasting.8. Agoldinlayoronlaydoesnot

becomeworntoproduceasub-mar-ginalsurface,nordoesitchipandfractureatthecavosurfacemargins.

9. Goldcastingshaveafavorablecoefficient of expansion with tooth structure.

Fig 2Longevity.TheDOinlayon#28hasbeeninser-viceformorethan60.

Fig 1 Conservativegoldinlays

�7�7 �7

Typical Cast Gold RestorationsFigs 3a to 3f

Inlay, onlays, gold foil 3a Inlays 3b

Onlay with buccal bale 3c 7/8 Crowns 3d

Full Crown 3e Distal of Cuspid 3f

�9�9

Similartootherrestorativematerials,goldcastingsalsohavetheirdisadvantages.Someofthedisadvantagesare:

�. Theproceduresforrestoringteethwithcastingsaremoretimeconsumingthanmostothermaterials.

2. Typicallythegoldcastingismoreex-pensive for thepatient than formostothertypesofrestorations.

3. Agoldcastingissomewhattechniquesensitive,and if it isnotdonewitharealconcernforexcellence,itprobableisnotassatisfactoryasothertypes.

4.Goldcanbeestheticallyunacceptableifplacedincertainareasofthemouth,particularlytheanterior teethandthebuccal areas of themaxillary poste-riors.

Fig 4Outlinewithoutcompositebuild-up(A)andwithbuild-up(B).

Preparation CavityPreparationSequence •Placerubberdam •Removalofpreviousrestorationand caries •Calciumhydroxidebase •Compositebuildup •Occlusalpreparation •Proximalboxform •Handinstrumentation •Occlusalbevel •Diskingofproximalwalls

•RubberdamPlacementofarubberdamisstandardprocedureforthistechnique.Itallowstheopera-tor to have the best field possible to work in. Theteethareisolated,gingivaltissueisslightlyretractedandsalivaiseliminated.Thetongue,cheekandlipsareeliminatedfromtheoperatingfield. The patient is not concerned about swal-lowinganypreparationdebris.Thequalityandquantityofrestorationsareenhanced.�-3

•RemovepreviousrestorationandcariesTheentireexistingrestorationisexpedi-tiouslyremoved.Careshouldbetakennottoextendtheoutlinebeyondtheexistingrestora-tion.Removeallremainingcaries.Theoperatorshouldnotbeconcernedaboutthepreparationtaperatthisstage.Theremainingtoothstructureisthenevaluatedandtheappropriaterestorationistreatmentplanned.Itishelpfultotransillu-minate with a fiber optic light during the evalu-ationoftheremainingtoothstructure.Someimportanttreatmentplanningconsiderationsare:amountandqualityofremainingtoothstructure,occlusion, significant fracture lines or enamel crazing,parafunctionalhabitsandgolddisplay.

•Calciumhydroxidebase A thin film of calcium hydroxide (Dycal) is placedontheinternalofthepreparationwithasmallcottonpellet.Itactsasaseparatorforeasyremovalofthecompositebuilduppriortocementation.Retentivepitsforretentionofthecompositecanbeplacedwitha#2roundburafterthebaseisset.

•CompositebuildupTheuseofacompositebuildupconservestoothstructurebecausetheoperatorcancontrolthedepthoftheocclusalandaxialwalls(Fig4).Itallowstheoperatortocutaprecisecavitypreparationthathasidealtaper,smoothnessandproportions.Anicepreparationwillfacilitatesubsequentproceduresofimpressiontaking,castingfabricationandseating.

�9�9 �9

Anauto-curecompositecanbeplacedwithapackinginstrumentorasyringe.Amatrixbandmaybeusedtocontainthebuildupcomposite.Thebuildupisusuallytotallyremovedpriortocementingthecasting.Thecastingoftenseatstoplacemorecompletelybecauseoftheabsenceofthecompositepulpalwall.

•Occlusalpreparation The preparation is cut with a #56 fissure bur for bicuspids and a #57 fissure bur for molars. The occlusal outline and pulpal floor are placed

Fig 5Idealburinclination.

Fig 7 Proximalwallenamelrods.

Fig 8 Idealpreparationwithuniforminclinationofwallsandtaper.Noreversecurve.

toadepthof�.5-2mmandauniforminclina-tionofthewallsof3-5degrees(Fig5).Thisresultsinanidealpreparationtaperof6-�0degrees ( Fig 6). The #56 and #57 fissure burs are4mminlengthandcanbeusedtodetermineproperdepth.

•ProximalboxformTheproximalboxformisestablishednextandisblendedwiththeocclusalpreparation.Theboxformiscutwiththesameoveralltaperas the occlusal. The width of the gingival floor isslightlylargerthanthediameterofthe#56burforbicuspidsandthe#57burformolars.Thebuccalandlingualwallsmustbeextendedfarenough(�mm)beyondtheadjacenttoothtofinish the casting. A smaller bur (169L) is some-timesconvenienttoestablishtheproximalwallextensionswithoutdamagingtheadjacenttooth. The proximal walls have a slight flare (~45˚) thateliminateunsupportedenamel

Fig 6 WallInclination/preparationtaper(draw).

2�2�

rods(Fig7).Maximizingtheuseoftheburtocutmostofthepreparationresultsinsmoothuniformwallsandlineanglesandthereforeverylittleeffortwithhandinstrumentsisnecessary(Fig8).

•HandinstrumentationsequenceSmooth,precisepreparationscanbecreatedwithminimumeffortwithverysharpinstru-ments. Instrumentsshouldbesharpenedbeforeeachprocedure.Thesequenceisillustratedin(Fig9).A. Pulpalandgingivalwallsaresmoothed-

witha42Soffanglechisel.

B. ProximalaxiallineangleIdeally,thislineanglecanbeformedwith oneortwostrokes.Themesialproximal

Fig 9 InstrumentationSequence:(A)Pulpal&gingivalwalls(B)Proximallineangles(C)Axialwall(D)Gingivalbevel

Fig 10Gingivalbeveltoolarge(A),idealbevel(B).

axiallineanglesareplacedwiththe42Schisel.Distalproximalaxiallineanglesareplacedwiththe43Schisel.

C.AxialwallBeginbyremovingthelittlegougeontheaxialwallformedfromcreatingtheproximalaxiallineangleandthensmooththerestoftheaxialwallasneeded.Thedistalaxialwallissmoothedwitha42Schisel.Themesialaxialwallissmoothedwitha43Schisel.

D.GingivalbevelItisasmallbevelthatis.5-.75mmwide.Thebevel should be definitive and smooth but not toowide(Fig.�0).Thereisnoadvantageincut-tingalargebevel.Thebeveliscreatedinthirdstopreventget-tingaswaleinthemiddlewhereitiseasiesttocut.Startbycuttingthebuccalandlingual�/3byplaningtowardtheproximalwall.Thenjointhebuccalandlingualsegmentsbycuttingthemiddle�/3ofthebevellast.Gingivalmargintrimmersthatarepre-sharp-enedbythemanufacturer(Suter)atamoreacuteangle than normal (30˚) are marked “Tucker.” The#232Tuckergingivalmargintrimmerisusedonthedistal.The#233Tuckergingivalmargintrimmerisusedonthemesial.

2�2� 2�

•OcclusalbevelThefunctionoftheocclusalbevelistore-movefragileenamelrodsandanyirregularitiesinthecavosurfacemargin.Itgivestheoperatoran opportunity to prepare a smooth, flowing, estheticallypleasingoutline.Thisbevelshouldbe placed with the same straight fissure bur ( #56 or#57)usedfortherestofthepreparation.Thebevelisplacedwiththeburinclineofonlyafewdegreesmorethantheocclusalwall(Fig��).Wheretheexistingoutlineisalreadyadequate,nobevelisneededsincetherearenounderminedenamelrods(Fig�2).

Fig 11Occlusalbevelisonlyafewdegreesmorethantheocclusalwall.Itcaninclude�/2-2/3oftheocclusalwall.

Fig 12 Nounderminedenamelrodsontheocclusal.

Fig 14DObicuspiddovetailandinternalbevel.

Fig 15 Gingivalwall.

•DiskproximalwallsA�/2inchgarnetdiskisusedtostraightentheproximalwalls.A#42Sor#43Schiselisusedto plane the proximal walls if space is insuffi-cientforthedisk.Thesingleplaneoftheproxi-malwallismaintainedsinceatwoplanewallisnotdesirable.Thediskcanalsobeusedtoblend

theboxformandtheocclusaloutline,removinganyremnantsofareversecurve. Asynopsisoftheentirepreparationse-quenceisshowninFigs�3ato�3l.

DOandMOBicuspidInlaysAdovetailiscutontheocclusalforretentionandresistanceform.Adovetailistheportionoftheocclusalthatismadewiderthantheisthmustopreventdisplacementofthecastingproxi-mally(Fig�4).Formostbicuspids,aninternalbevelisrec-ommendedforaddedresistanceandretentionform(Fig�4,Fig�5).Thebevelalsoactsasaseatingguideforthesesmallercastingsduringcementation(Fig�6).Withoutthisbevel,thecementtendstoforcethecastingawayfromtheaxialwallduringseating.Theentiregingivalwalliscuttomeettheaxialwallatanacuteangleutilizinganon-Tucker#232or#233gingivalmargintrimmer.

2323

Inlay Preparation Sequence

Fig 13aOcclusalpreparation. Fig 13bProximalpreparation.Fig 13cPreparationcompleted#57 fissure bur for molars, #56 with bur.fissure bur for bicuspids.

Fig 13d Instrument pulpal floor Fig 13eInstrumentgingivalwall. Fig 13f Instrumentproximalwithenamelhatchet. lineangle.

Fig 13gInstrumentaxialwall. Fig 13hGingivalbevelcutwith Fig 13i Mediumgarnetdiskon Tuckergingivalmargintrimmers.proximalandocclusalwalls.

Fig 13jOcclusalbevelwith Fig 13kOcclusalviewof Fig 13lProximalviewof fissure bur. completed preparation. completed preparation.

Figs 13a to 13l

2323 23

Thebevelsontheseinstrumentsarelessacute(45˚) than the ones marked Tucker (30˚)(Fig 17). Theaxialwallisinstrumentednexttoinsurethatitisnotundercutorirregularatthegingivo-axial line angle. The gingival floor must be cut approximately.5mmwiderthanusualtoaccom-modateaninternalbevel

MODInlayMODsareprobablythemostcommonpreparationsmade.Theopposingmesialbuc-cal/distallingualproximalwallsandthemesiallingual/distalbuccalproximalwallsarecutap-proximatelyparalleltoeachother.Thesewallsarethenretentiveagainsteach

Fig 16Internalbevelfuctionsasaseatingguideandgivesaddedretentionandresistanceform.

Fig 17 The Tucker margin trimmers 30˚(top)forgingivalbevel.Non-Tuckermargintrimmers45˚(bottom) for internal bevel.

Fig 18Opposingproximalwallsofmesialanddistalboxforms(MB/DL&ML/DB)areparallelandretentivewitheachother.Notethenicesymetryofthepreparation.

Fig 19 CoeandEmerycheckbitetrays.

ImpressionForoneortwocrownsorperhapsaquadrantofinlays,thequadrantcheckbiteisaclinicallyproventechnique.��.Ametalcheckbitetray(Coe)isrecommended.Whenthebackofthistraydoesnotallowthepatienttobiteintocentricocclusioncomfortably,asmallerwiretray(Em-ery)isused(Fig�9).Theimpressionistakenasthepatientbitesintocentricocclusion. Theadvantageofthisprocedureisthattheimpres-sionregisterstheocclusionastheteethareinfunctiontherebyallowingamoreperfectocclu-sionoftheopposingarches.Inturnthisusuallyallowsthecastingstobeplacedwithoutneedtorelievetheocclusion.Thismoreaccurateoc-clusionregistrationisprobalyduetothesmallamountofmovementintheperiodontalmem-branethatallows

otherandgivethepreparationanicesymmetry(Fig�8).Thetwoaxialwallsarealsonearlypar-alleltoaddretentiveformtothecavity.�0

Seating

Function

2525

theteethtomorecompletelyinterdigitateastheimpressionregisterstheirpositioninfunction. TheresultingquadrantmodelsmountedfromthecentricocclusionbiteoftheimpressiononasimplehingearticulatorisshowninFig20. Forgingivalretraction,abulky,non-braidedcord(Gingivi-Pak#3,Surgident)ispreferred.Thiscordprovidesgoodretractiondepthbelowthepreparationandgoodwidthofthesulcus.Thepopularbraidedcord,doublepackmethodwhere the first chord remains in the sulcus dur-ingtheimpressiongenerallydoesnotprovidethedepthandwidthdesiredforgoodimpressions.Invariablythetissueseemstobleedifbothchordsareremoved.A25%aluminumchloridesolution(Hemodent)isusedfor

Fig 20Quadrantmodelwithhingearticulator. Fig 21 DuraSealacrylicandtemporarystopping.

Fig 22 Temporarystoppingplaced.

hemorrhagecontrol.Itseemstobekindtothetissue and leaves no film on the preparation.Oneortwocordsareplacedaroundthepreparation.Twocordsseemtoworkwellin-terproximally.Theyshouldbeleftinplaceforabout3–4minutes.Priortotakingtheimpres-sion, check the fit of the tray and have the patient practicegettingthe“feel”ofbitingintocentricocclusionwiththetrayinplace.Notetheoc-clusiononthecontralateralsideasaguidesoyouknowwhenthepatientisbitingintocentricocclusion. Iftheoperatorchoosestouseapolyvinylsiloxaneimpressionmaterial,itisadvisabletouseonlythelightbodymaterialfortheentireim-pressionbecausefoldscanoccurattheinterfaceofthelightandheavybodythatareunacceptableforinlayimpressions.Thepotentialsetinhibi-

tionduetotherubberdamorlatexglovescanbecounteractedbycleaningthepreparationandadjacentteethwithacottonpelletsaturatedwithhydrogenperoxideafterthecordisremoved.Rinsethoroughlybeforetakingtheimpression.Beforetheimpressionmaterialismixed,theoperating field should be spray washed and dried andthecordisslowlyremoved.Itischeckedforadequateretractionandthatthereisnohemor-rhage.Ifretractionisnotadequateorifthereishemorrhage,repack.Ifitissatisfactory,itmustbemaintaineddryandtheimpressionmaterialismixed.Syringeimpressionmaterialintothepreparation,placethecheckbitetrayandhavethepatientbiteintocentricocclusion.Bepre-paredto“assist”thepatientintotheproperjawpositionwithgentlepressureonthechin.Con-tinuetomonitorandsupportthepatientforafewminutestomakesurethatthereisnodistortionintheimpressionduetopatientmovement.

2525 25

Checkthesetofthematerialwiththetipofthecottonpliers.Whenthematerialseemstobeset,allowonemoreminuteofsettime.Removetheimpressionwithafastmovementinaverticaldirectiontominimizedistortionandtearing.

Temporization Armamentarium Soft,fastsetacrylic(DuraSeal)

Temporarystopping(guttapercha)LargestraightbrushWoodsenhandinstrument2dappendishesLighter (flame)

Fig 23DuraSealplaced.

Fig 24Inadequateexpansion:inlayloosewith marginalgaps,crownwillnotcompletelyseat.

Fig. 25Inlaywithoutproperexpansion.Notemarginalgapsandcementmargins.

Asemi-softacrylic(DuraSeal,Reliance)isidealfortemporizinginlaysandonlays(Fig2�).Itiseasyandquicktoplace.Nocementisusedsoitiseasilyremoveandthereisnocleanup.Apieceoftemporarystoppinglargeenoughtocoverthegingival2/3ofeachboxformisheatedwithadisposablelighterandplacedwithaplas-ticinstrument(packer/pluggercombination).Itactslikeadamsothattheacrylicdoesnottouchthetissue,toaccomplishthis,thestoppingmustbeplacedagainsttheadjacenttoothaswell.Thestoppingshouldnotextendabovethecontactstoallowtheacrylictobe“lockedin”atthecontactsoftheadjacentteeth(Fig22).Excessstoppingcanbecontouredandremovedwithaheatedinstrument.

Theacrylicisplacedwiththeliquid/powdermethodusingafairlylargebrush.Buildacrylictocontour,besuretocoverallmarginsofthepreparation.Workquicklysothatthepatientcanbiteandgothroughexcursivemovementswhiletheacrylicisstillfairlysoft(Fig23).Theacrylic can be molded with moistened fingertips. No attempt is made to refine the occlusion unless there is a gross excess of acrylic. Excess flash canberemovedwithacleoidoraheatedinstru-ment.Multiplepreparationscanbeconnectedwithasinglelayerofacrylic.Besuretotellthepatient they will not be able to floss.

2727

Therearemoresophisticatedmethodstotemporizeinlaysandonlaysbutthismethodisveryfastandeasyduringbothplacementandremovalsincenotemporarycementisused.Pa-tientsseemtotoleratethistemporarywell.Thegingivaltissueresponseisgenerallysurprisinglygood.

Lab Theskillinwhichanoperatorcanprepareteethandseatcastingsisaveryimportantpartofthistechniquebutunlessqualitycastingsarefabricatedinthelaboratory,itisimpossibletocreateconsistentlyexcellentrestorationsforourpatients.Abasicunderstandingofthelaboratoryproceduresisessentialtobeabletocritiquecast-ings and to communicate with your lab if refine-mentsarenecessary.Itisnotwithinthescopeofthischaptertodiscusslabproceduresindetailbutcastingexpansionwillbecoveredbecauseitisanimportantconcepttounderstand. Goldshrinksapproximately2.4%ofits

Fig 26 ExpansionrecommendationsforNovocast

Water/Powder(cc)Temperature˚FRingLinerCrown �5.5 ��75 23/4,7/8Cr �8 ��50 2MODBL �8 ��50 2MOD �8.5 ��50 2DO,MO,Occ �5 ��75 2

massasitiscastandgoesfromaliquidtoasolid.�5Ifnothingisdonetocompensateforthis gold shrinkage, inlays will fit loosely with marginalgapsandcrownswillnotseattoplace(Fig24).Thetermexpansionisusedtodescribemethodsusedtocompensateforgoldshrinkage. Is the gold shrinkage clinically significant? Theocclusalinlayin(Fig25)isanexampleofaninlaythatistoosmallforthepreparation

resultinginmarginalgapsthatcannotbeclosedduring finishing. Theinvestmentproceduresarewherethecompensationforgoldshrinkagetakesplace.Themethodstoincreaseexpansionbymanipu-latingtheinvestmentaretodecreasethewaterinthewater/powderratio;increaseoventempera-ture;increasethenumberofringliners;hydro-scopic expansion in water bath (100˚F). Asmanyvariablesaspossibleshouldbeeliminated.Onlywater/powderratioandoventemperatureshouldbevariedtogivemaximumaccuracytoeachtypeofcasting.Itisimportanttorealizethateachtypeofcastinghasitsownrequirementasregardstoexpansion.Itmightbenotedthatthedoubleringlineraccountsforthenecessity of fifty degrees less furnace tempera-ture.Thisallowsthecastingtemperaturetobebelowthatwhichcausesbreakdownoftheinvestment. Dr.RichardV.Tucker’srecommenda-tionsforexpansionwithNovocastinvestmentareshowninFig26.

SeatingCastingsshouldbeseatedwithanesthetic.Thetemporaryisremovedandarubberdamis placed. The fit of the casting is verified on thepreparationandthecontactsareadjustedifnecessary.

2727 27

Justpriortocementation,allofthecompos-itebuildupshouldberemoved.Ahighspeed#2roundburcanbeusedtosectionit.Theprepa-rationiscleanedandadesensitizingagentlikeGluma3isplacedonthedentin.Aslowsettingmixofzincphosphatecementispreparedbyaddingsmallincrementsofpow-derslowlytotheliquidoveraperiodofabouttwominutesuntilthemixturewilljustdropfreelyfromthespatula.Cementisplacedbothinthecastingandthepreparation.Thecastingisseatedandthenconsiderablepressureisplacedwithapointedorangewoodstick.Theorangewoodstickislightlymalletandheldforseveralsecondsuntilthehydraulicpressureofthece-menthasdissipated.Excesscementcannowberemoved.

Fig 27 Moore�/2inchdisks. Fig 28Polishingpowders.

TheFinishingSequenceDisks(1/2”): medium garnet, fine

sand, fine cuttle (Fig 27).Powders: slurry of flour pumice,

aluminumoxidewithalcohol(�5 micron),aluminumoxidedry(�

micron)(Fig28).Note:Continuousairshouldbeblownonthecastingduringdiskingtodissipatetheheatgeneratedinthegold.�6

Enamelandgoldarereducedtothesameplaneandthemarginsareburnishedwithme-diumgarnetdiskspriortohardeningofthece-ment.Thedisksshouldalwaysberotatedfrom

goldtowardthetooth.Thegarnetdiskistheworkhorse of the finishing process and usually severaldisksareused.Allmarginscanusuallybe finished with a straight hand piece except themesiallingualarea,whereacontra-angleisusedwiththegritofthedisktowardtheman-drel.Aftercompletionwithgarnetdisks,mostoftheworkwillhavebeendonesothegoldandtooth are merely finished so that the scratches are smaller. The fine sand disks are used next. Thegingivalonethirdofthecastingandgingival margins can be finished with finishing strips. After completion with fine sand disks, a narrow eighteen-inch medium garnet finishing stripthathasbeencuttoapointispassedunderthecontact.Usuallytwoorthreeswipeswiththe strip will adequately finish this area. Care mustbetakennottoovercuttherelativelysoftcementum. A fine cuttle stip should be used next inthesamemanner.

Finecuttledisksareusednexttoremoveanyremainingscratchesandpolishthegold.The key to fine finishing seems to be good use ofcuttledisks.Asdisksbecomeusedandworn,thescratchestheyleavebecomesmaller.Ithasbeensaidthatdiskshavethreelives:new,usedand worn. When gold is finished to a “third life” worncuttledisk,itcanthenbepolishedwithpowders to a mirror-like high finish. This

2929

Fig 29 Slight reflection at functional margins of gold inlay.Openingandgapformationatfunctionalmarginsofbothporcelaininlays..

Fig 30Estheticallypleasingrestorationofmaxillaryposteriorteethwithconservativeoutlinesallowingpreservationofthebuccalenamel.

Occlusionandmarginalintegrity Basedonresults,themarginalintegrity

oftheenamel/goldcavosurfacemarginholdsupwellunderocclusalstress.Thegoldandtooth wear at a similar rate and the coefficient ofexpansionissimilar.Therefore,preparationcavosurfacemarginscanbeplacedwithouttoomuchconcernfortheopposingocclusion.Thegold margin exhibits only a slight reflection even aftermanyyearsoffunctionwhereasfunctionalmarginsofamalgam,compositeandporcelainwilleventuallyopen(Fig29).

Esthetics Ifconservativegoldrestorationsareproperly designed and finished, gold display can beminimalornonexistent.Atoothcanbefunc-tionallyrestoredforalifetimewhiletheestheticsoftheoriginaltoothcanbemaintained

Fig 31Slightgolddisplayatocclusalof7/8crown#4.

can be accomplished by finishing the casting a sectionatatimewithallthreelivesofthesamecuttledisk.Thelifeofadiskcanbeacceleratedtoamorewornstagebyrotatingitonthemirrorhandle. Difficult access areas might be finished with the smaller 3/8 inch disks. Small finishing dia-mondsfollowedbybrownie,greenieandsupergreenie points work well for grooves and fissures thatarenotaccessiblewithdisks.

Thecastingisthenreadytopolishwithpowders.Caremustbetakenbecausethepow-derscutthetoothandgoldatdifferentratesandcan open up a margin or cause a reflection. This is especially true with flour pumice. Each of the powdersshouldbeusedwithaclean,ribbedrub-bercuponacontra-angle.Aslurryofpumiceisused to give the gold a uniform finish after the disks.�5micronaluminumoxidewithalcoholis used next. The final powder, 1 micron alumi-numoxide,isuseddrywhiletheassistantblowscontinuousairandsuctions. Aftertherubberdamisremoved,theoc-clusionischeckedwitharticulatingpaper.Adjustmentsaremadewithahighspeedgreenstoneandpolishedwithhighspeedbrownieandgreeniepoints. Thelongevityofconservativegoldcastingsislargelyduetoourabilitytocreatecastingsthat fit well and are nicely finished with marginal gapsoflessthan50microns.�7Keenan�8suggeststhat a well finished gold surface accumulates less plaque.

2929 29

Fig 33 Magnification.

Magnification The use of magnification for this type of dentistryisveryhelpful.Ourabilitytodeliverqualityrestorationsisenhancedwiththeuseofsome type of magnification. A range of 2 - 3.5 dioptersisrecommended(Fig33).

Fig 32Colordiscrepancyofaporcelaincrownasnatu-ralteethdarkenwithage.

(Figs30,3�).Ifatoothcannotberestoredes-theticallywithaconservativegoldrestoration,thenaporcelainrestorationmightbethebesttreatmentofchoice.Keepinmind,however,thatthecolorofaporcelainrestorationwilleventual-lynotmatchtherestofthedentitionasteethageandbecomedarker(Fig32).Soaconservativegoldrestorationisoftentheideallong-term

esthetictreatment.

VARIATIONS OF CAVITY DESIGNInlay vs onlayTherestorationofchoiceforaposteriortoothisaninlaybecauseitpreservesmorefunctionaltooth structure and can be predictably fitted and finished. It is often very esthetic because most of theenamelcanbepreserved.Itistheexperienceoftheauthorsthatcuspfractureofaninlayisrare.Anonlayrestoresthestrengthofatoothbutdestroysmoretoothstructureandthegolddisplaycanbeunesthetic.

OnlayAnonlayisindicatedwhenthereisnotenoughsoundtoothstructureremainingtosupportaninlay.Thebasictechniqueistoalwayscutthemod preparation first and then onlay the cusps as the final step. In questionable situations where the

remainingtoothstructuremightsupportaninlay,generallyitisadvisabletoonlaythetoothsincepredictablelongevityisourgoal.Ifthereissuf-ficient tooth structure, only the weakened portion ofthetoothcanbeonlayed.However,inmostcasesbothbuccalandlingualcuspsareonlayedtodistributetheocclusalforcesoverabroadersurface.Anonlayedtoothcanbestrongerthantheoriginalnon-restoredtooth.Cuspreduc-tionforafunctionalcuspisabout�.5-2mm.Non-functionalcuspscanbereducedless.Theappropriatebevelsareplacedwitha7404bur.Theresultinghollowgrindbevelgivesbulkofgoldatthebevelandprovidesaverynicemarginto wax and finish to. Step-by step procedures for onlaysareshownonFigs33ato33L.

3�3�

LoweronlayBothcuspshavebeenreducedandcounterbev-eled.Thecounterbevelonthebuccalfunctionalcuspislargerthanthenon-func

UpperonlayProperreductionofthecuspsisshownforanupperonlay.Acounterbevelisplacedonlyonthefunctionallingualcusptominimizegolddisplay.

InvisibleOnlay

Indication This preparation is a modification of the traditionalonlaypreparationtominimizegolddisplayontheocclusalbuccalmarginofupperbicuspids.Armamentarium1. #56 fissure bur2. Brasseler7404bur3. Finecuttledisk

Preparationsynopsis�. Thelingualinclineofthebuccalcusp

isreducedsteeplyfromthecusptip to the level of the pulpal floor.

2. Theincreasedthicknessofgold protectsthecuspandallowsthegold tobethinnedonthebuccalsoit cannotbeseen.

3.Moreofthelabialportionofthebuccalcusp remainswhencomparedtothetraditionalup-

peronlay.

Preparationsequence�. Thelingualinclinereductionofthe

buccalcuspisdonewitha#56bur.2. A fine cuttle disk is used to place a

microscopiccounterbevelonthe buccalcusp.

3. Thelingualcuspreductionand counterbevelarecutinthetypical manner.

tional lingual cusp.

3�3� 3�

EstheticOnlay

Fig 34jBuccalocclusal Fig 34kMicro-bevelbuccalcusp Fig 34lEstheticonlaycompleted. reduction to pulpal floor. with fine cuttle disk.

Fig 34gLingualcounterbevel Fig 34h Micro-bevelbuccalcusp Fig 34i Upperonlaycompleted.

Fig. 34d Counterbevelon Fig 34e Onlaypreparation Fig 34f Occlusalreductionboth buccal and lingual with completed. #56 fissure bur.7404bur.

UpperOnlay

LowerOnlay

Fig 34a Cut MOD first. Fig 34b OcclusalreductionwithFig 34cOcclusalreduction #57 fissure bur. completed.

with7404bur. with fine cuttle disk.

Onlays Fig 34a to 34l

3333

Molar7/8Crown

Indication Thispreparationisindicationwhenthetooth

needstobeboundtogetherorwhenthetoothisbadlydestroyedbutthereisstillagoodmesialbuccalcusp.

Armamentarium 1. 57 fissure bur 2. 860-0�2diamond 3. 860-0�4diamond 4. 42Sand43Soffanglechisels 5. Mediumgarnetdisk 6. FinecuttlediskPreparationsynopsis 1. A definitive occlusal center line angle

iscreatedastheocclusalisreduced. 2. Aminimaltaperofthepreparation

resultsinparallelwalls. 3. Themesialhollowgrindiscutto

drawslightlytothelingual.Itallows

thiswalltohavemorelength,increasingretention.4. Thebuccalwalliscutrelatively

straightacrossandthedistalbuccal angleofthetoothisleftrelatively squareforaddedretention.This resultsinasmallirregulartriangleat the distal buccal finish line.

5. Thedistalbuccalwalloftheprepara tioniscuttofunctioninconcertwith themesialhollowgrind.

6. A definitive distal buccal line angle is createdwithenamelhatchets.

Preparationsequence�. A57burisusedfortheocclusal

reduction. There is a definitive occlusallineangleinthemiddle.

2. Thesmall860-0�2diamondmaybe usedtobreakthroughtheinterproxi malcontacts.

3. Thelarger860-0�4isusedtocutthe restofthepreparation.First,ahol lowgroundwalliscutonthemesial. Bycuttingthisareawithaslight lingualdrawthemesialbuccalwall ofthepreparationcanbelongerfor additionalretention.Thelingualand distalwallsarecutnext.

4. Thebuccalwalliscutfairlystraight acrossandthedistalbuccallineangle isquitesquaretotryandmaintainan actualbuccalwall.Thisresultsina littletriangleorirregularityonthe distal buccal finish line. This is left sincesmoothingthisareawould resultinanundercut.

5. The42Soffanglechiselcreatesa sharplineangleinthebackofthe mesialbuccalcusp.The43Sisthen usedtoslidedownthebuccalwallto completethelineangle.Thisangle shouldbeabout90°.

6. Themediumgarnetdiskisplacedon thedistalbuccalwalltosharpenthe outlineofthepreparation.

3333 33

occlusaledgeofthebuccalcusptodullandsmooththemargin.

Premolar7/8Crown

Difference from the molar preparation:• Thesmall860-0�2diamondisalways

usedfortheinitialproximalreduction.Overcuttingordamagetotheadjacenttoothmightresultfromusingalargerburinitially.

• Thedistalwallhasaslighthollowgrindcurvethatseemstoincreaseresistanceformenoughtoallowamoreconserva-tivereductionofthebuccalwalltomini-mizegolddisplay.

FullGoldCrownVariationsThevariationsallowthebuccalmargintobekeptwellabovethegingivaforbettertissuehealth.Eachvariationhasafeaturethataddsre-tentionandresistanceformtothepreparationtoallowahighbuccalmargin.Thebuccalmarginis finished like an onlay.

•HollowGrindCrown

IndicationsLowermolarfullcrownpreparationswhereoldrestorationsorcarieswouldrequireproximalmarginsthataredeepgingivally.

Preparationsynopsis�.Agentlebuccaltolingualhollowgrindcurveonbothmesialanddistalwallsprovideadequateresistanceform.2.Retentionisenhancedbythelongmesialanddistalwallsofthehollowgrindthatresultedfromtheincreasedgingivaldepthofthepreparation.Theyarealsocutquite parallel.Armamentarium1. 57 fissure bur2.860-0�2diamond

7. The fine cuttle disk is placed on the

3535

3. 860-0�4diamond4. Brasseler7404bur5. Finecuttledisk

Preparationsequence�. Theocclusalreductionisdonewitha57

bur.Asharplineangleiscreatedinthecenteroftheocclusal.

2. The860-0�2diamondmaybeusedtobreakthecontactsinitially.

3. Thelarger860-0�4isusedtocutthebulkofthepreparation.

4. The 7404 bur is used to finish the buccal margin to provide a sharp smooth finish linethatprovidesadequatebulkofgoldfor casting and finishing.

5. A fine cuttle disk is used to smooth the occlusallineangles.

•CrownwithShoulder

IndicationLowermolarfullcrownpreparationswithoutextensiveproximalinvolvementwhereadeephollowgrindwouldbeinappropriate.

Armamentarium1. 57 fissure bur2. 860-0�2diamond3. 860-0�4diamond4. Finecuttledisk

PreparationsynopsisAdditionalretentionandresistance

formiscreatedbymakingabuccalwallmoreparalleltotheotherwallsbyplac ingabuccalshoulder.

Preparationsequence�. Thepreparationiscutinthetypicalman-

nerforatraditionalfullcrownexceptforthebuccalwall.

2. Theshoulderiscutwitha57burandblendedintotheinterproximalwiththe860-0�4diamond.

Brasseler7404BurPreparationVariationsThisbulletshapedburproducesaverysmoothhollow ground margin that allows good defini-tionandbulkofgoldatthemargins.�9

•HollowGrindMarginalRidge

IndicationThin,weakeneddistalmarginal

3535 35

•OLUpperMolar

Indication OLgrooveonuppermolars.

PreparationSynopsis�. Theentirecavityiscutwiththe7404.2. Thissimplepreparationwillhave

a rounded pulpal floor and no line angles.

3. Drawiscreatedbytheshapeoftheburonly.

•Midwest7404PotHoles Indication Wideopencavityneedingadditional retentionandresistanceform.Thetypical situationisalargecavitywithacompos itebuildup.

ridge,usuallyonsecondmolar.

SynopsisThemarginalridgecanbeexpedientlyincludedintothepreparationwithoutadistalboxorhandinstrumentation.

•BuccalExtension(Bale) Indication

The finger-like extension on the buccal of molarsisplacedwhenthereisextensivebreakdownofthelingualcusp.Itallowsthecastingtoengagethestrongerbuccaltoothstructure,reducingthestressonthelingual.

PreparationSynopsis�. Theextensionmusthaveadequate

lengthandshouldnottapertoomuchtothelingual.

2. Adequatedepthisnecessaryforenoughbulkofgoldtopreventthecastingfrombendinganddistorting.

3737

Preparationsynopsis�. AMidwest7404isusedbecauseithas

theidealshapeofmoretaper.2. Thedepthofthepotholeisatleast2

mm.Itisoftenmoresinceweliketocutthroughtheentiredepthofthebuilduptodentin.

3. Theentirecompositebuildupisremovedpriortocementation.

Impression�. Breakofftheendofananestheticneedle

toremovethebevelwithoutclosingthelumen.

2. Placetheneedleinthepotholeandinjectimpressionmaterial.

3. Theneedleallowsairtoescapeandthusdecreasesvoids.

SlotInlay

Indication

Restorationofthedistalofacuspid withasmalllesionorasmallexistingrestoration.20

Armamentarium1. 169L fissure bur2. 44Sand45Soffanglechisels3. 232and233gingivalmargintrimmers4. Tucker232and233gingivalmargin

trimmer5. 55 fissure bur

Preparationsynopsis�. Handinstrumentationresultsinsharp

internallineangles.2. Twoplanelabialandlingualwallsen-

hanceretention.3. Aninternalbeveladdsretentionandaids

inseatingofthecastingduringcementa-tion.

4. A small definitive gingival bevel is placed.

Preparationsequence�. Openthecavitywiththe�69Lburand

establishthelabialandlingualextensionsandthegingivalwall.Thecavitylookslikeacrescentatthistime.

2. Usethe�69Lburtoenhancetheaxiallineangleslabiallyandlinguallyforre-tention.Thiscreatesthetwo-planelabialandlingualwalls.

3. Usethenarrow45Soffanglechiseltoplacetheproximalaxiallineangles,whichcreatesharpretentivewalls.

4. Usingthe#233margintrimmerplaceaninternalbevelonthegingivalwall.Slidedownboththelabialandlingualwallsto define the line angles and sharpen the pointangles.

5. Smooththeaxialwallwiththe44Soffanglechiselsinceitwillberoughfrominstrumentingtheinternalbevel.

6. Place a small definitive gingival bevel withthe232Tuckermargintrimmer.

7. A 55 fissure bur is used for the occlu-salbevelwhichremovesunsupportedenamel,smoothestheoutline,andcreatesa“funnel”whichaidsinseating.

3737 37

Armamentarium

DistalHollowGrind

Indication

Restorationofalargecariouslesionorlargeexistingrestorationwithalingualdovetail.20

Armamentarium1. 56 fissure bur2. Brasseler7404bur

Preparationsynopsis�. Nohandinstrumentsareusedforthis

preparation.2. Thepreparationconsistsofalingual

dovetailandadistalhollowgrind.3. Ithasaneasydrawtothelingualbecause

therearenosharpinternalangles.

Preparationsequence1. Place the lingual dovetail with a 56 fis-

surebur.Itdrawsperpendiculartothelingualcavosurfacewithequaldepthinallaspects.

2. TheBrasseler7404isusedtoplacethedistalhollowgrind.Thehollowgrindisparalleltothelabialsurface.Theaxialwalltaperiskepttoaminimum.

3. Placealightocclusalbevelwiththe7404.

DistalHollowGrindwithaPin

IndicationLargecavityneedingadditionalretentionandresistanceform.20

�. #6roundbur2. 169 L fissure burPreparationsynopsis�. 50%ofdistalhollowgrindpreparations

needapin.2. Thepinisplacedasfarawayfromthe

primaryretentionofthedovetailaspos-sible.

Preparationsequence�. Acountersinkisplacedwithahigh

speed#6roundbur.2. Thepinholeisplacedwitha�69Lburto

adepthofabout�.5mmandisparalleltothelingualdrawofcavity.

ConclusionAlthoughgoldcastingsarerelativelytech-niquesensitive,anddemandingontheoperator,whenthistyperestorationiswelldoneitoffersagreatsatisfactiontothepatientintheformofcomfortandpermanence.Itisthedesireoftheauthorsthatmorestudentsanddentistsacquiretheknowledgerequiredtoperformthistypeservicefortheirpatientsandperformthistypeofdentistryroutinely.

3939

PitGoldFoil

Indication Oftenappropriatewhereacastinghasbeenplacedtorestorethetoothanda smallbuccalorlinguallesionremainsthatcanberestoredseparately. Armamentarium Preparation 1. 55 fissure bur 2.35invertedcone 3.7404bur Condensation �.Powderedgold(EasyGold) 2..5foilcondenser 3..7foilcondenser 4.Goldfoilmallet 5.Goldfoilcarrier 6.Woodbury-Myerholder 7.Goldknife 8.Varneyfootcondenser 9.Cohesivegoldpellets Finishing 1. Disks: medium garnet, fine sand, fine cuttle 2.Cleoid 3.Beavertailburnisher 4.Ribbedrubbercups 5. Polishing powders: #4 flour pumice, 15 and 1 micron aluminum oxide. Preparationsynopsis Asmallcircularpreparationwithaxialretentioncutwitha35inverted oneandasmallocclusalbevelplacedwitha7404bur. Preparationsequence 1. Use a 55 fissure bur to outline the cavity. An ideal depth is 1.5 mm. 2.Usea35invertedconetogivetheaxialwallalittleretention. 3.The7404burisusedtosmooththeoutlineformandplacealittle bevelonthecavosurfacemargin. Foilplacement �.Usea.5or.7condenser.Usethelargestcondenserthatthecavitywill accommodate. The bulk of the restoration is filled with powdered goldbecauseitisquickerandeasier. 2. Anneal the powdered gold over a flame using a foil carrier.

3939 39

eachpelletinitiallywithhandpressureandthencondenseusingthe mallet. 4. Fillthecavitytothebevelwithpowderedgoldsothatthereisonly about .5 mm left to fill. 5. The rest of the cavity is now filled with cohesive gold because it is denserandwillhavelessporosity.Thecondensationforceisnow directedtowardtheenamelbevel.Thiswillmakethegoldtighttothe wallsaswellasprotectthefragileenamelduringcondensation. 6. Asthegoldisaddedtobuildupthecontour,excessgoldisremovedbeyondthemarginwith

a gold knife. It can be difficult to remove later and we may lose the relationship of where the marginactuallyexists.

7. Verify if the cavity is filled by using an explorer from gold toward the tooth. If we do not feel an edge of tooth, the cavity is filled.

8. Use a Varney foot condenser to finalize the condensation. It takes out the hills and valleys a bitandsmoothesthegoldtooneplanealittlemore.

Finishing 1. Always blow air when finishing gold with disks because the heat generated can damage the

pulp. 2. Removethebulkofgoldwithamediumgarnet.Careshouldbetakenaroundthemargins

withthisdiskbecausetheenamelisquitefriableandwedonotwanttobruisetheenamelwithtoocoarseofadisk.

3. Next use the fine sand disks. Use a cleoid to remove any surplus flecks of gold since the diskswillcontinuetocarrythegoldoverthemargin.

4. Useabeavertailburnishertoburnishandworkhardenthegoldabit. 5. Follow with the fine sand again to remove any irregularities produced as the gold was work

hardened. 6. The last disk is the fine cuttle. It does not require much effort because of the step-by-step

finishing sequence we have used. Polish �. Usingaribbedrubbercup,beginpolishingwith#4pumice.Donotusepumicetoolong

becauseitremovestoothstructureandgoldatdifferentrates. 2. We now use aluminum oxide 15 microns. The final finish is with the 1 micron aluminum

oxide.

3.HoldthegoldinthecavitywiththeWoodbury-Myerholderandcon densewiththedirectionofforcedirectlyintothecavity.Condense

4�4�

References

�. GergelyEJ.Rubberdamacceptance.BrDentJ�989;�67:249-252.2. ReuterJE.Theisolationofteethandtheprotectionofthepatientduringendodontictreatment.

IntEndodJ�983;�6:�73-�8�.3. ChristensenGJ.Usingrubberdamstoboostquality,quantityofrestorativeservices.JAmDent

Assoc�994;�25:8�-82.4.TuckerRV.Class2inlaycavityprocedures.OperDent�982;7:50-4.5. JorgensenKD.Therelationshipbetweenretentionandconvergenceangleincementedveneer

crowns.ActaOdontolScand�955;�3:35-40.6. Kaufman EG, Coelho DH, Colin L. Factors influencing the retention of cemented gold castings. J

ProsthetDent�96�;��:487-502.7. DykemaRW,GoodacreCJ,PhillipsRW.Johnston’sModernPracticeinCrownandBridge

Prosthodontics,ed4.Philadelphia,WBSaundersCo,�986,p24.8. ShillingburgHT,HoboS,FisherDW.PreparationsforCastGoldRestorations.Chicago,Quin-

tessencePublCo,�974,p�6.9. TylmanSD,MaloneWFP.Tylman’sTheoryandPracticeofFixedProsthodontics,ed7.StLouis,

CVMosbyCo,�978,p�03.�0.El-EbrashiMK,CraigRG,PeytonFA.Experimentalstressanalysisofdentalrestorations.Part

IV.Theconceptofparallelismofaxialwalls.JProsthetDent�969;22:346-353.��.ParkerMH,CameronSM,HughbanksJC,ReidDE.Comparisonofocclusalcontactsinmaxi-

mumintercuspationfortwoimpressiontechniques.JProsthetDent�997;78:255-259.�2.NoonanJE,GoldfogelMH,LamberRL.Inhibitedsetofthesurfaceofadditionsiliconesincon-

tactwithrubberdam.OperDent�985;�0:46-48.�3.CookWD,ThomaszF.Rubberglovesandadditionsiliconematerials.Currentnoteno.64.Aust

DentJ�986;3�:�40.�4.KahnRL,DonovanTE,CheeWWL.Interactionofglovesandrubberdamwithpoly(vinylsilox-

ane)impressionmaterial:Ascreeningtest.IntJProsthodont�989;2:342-346.�5.HollenbackGM,SkinnerEW.Shrinkageduringcastingofgoldandgoldalloys.JAmDentAs-

soc�946;33:�39�-�399.�6.CoolyRL,etal.Heatgenerationduringpolishingofrestorations.QuintessenceInt�978Dec;

9(�2):77-80�7.SkinnerEW,PhillipsRW.Thescienceofdentalmaterials.6thed.Philadelphia:WBSaunders;

�967.p.473-74.18. Keenan MP, et al. Effects of cast gold surface finishing on plaque retention. J Prosthet Dent

�980Feb;43(2):�68-�73.�9.TuckerRV.Variationofinlaycavitydesign.JAmDentAssoc�972Mar;84(3):6�6-620.20.TuckerRV.Goldrestorationsofthedistalaspectofcuspidteeth.Signature�996:4-9.

4�4� 4�

AllAboutPinsinGoldCastingsRichardD.Tucker,DDSRichardV.Tucker,DDS Inlays are so much fun to design and finish, and they are so beautiful. A simple MO, DO, or perhapsanMODgivessuchexceptionalservicetothepatient.However,sometimesthereisinsuf-ficient tooth structure remaining to provide enough retention or resistance form to retain the simple castingwewouldliketoplace.Ratherthanapreparationforamoreextensivecastingrequiringtheremovalofmoreofthepatients’healthytoothstructure,wecangaintheresistanceformand/orretentionneededthroughtheadditionofoneormorecastgoldpinstoourgoldcasting.Thereare4typesofpinsavailabletosatisfyourneedsformoreresistanceformandretention.TheShooshanpin,the700 tapered fissure pin,avariationonthiscalledthe 700 tapered fissure slot,andtheTuckerpin. TheShooshanpintechniquewasdevelopedbyDr.DavidShooshan,anoteddentistinsouthern California. The position of the pin hole is first marked with a #4 round bur to half the depth oftheburhead.Thisformsthe“countersink”aroundthepinholeopeningwhichwillgivethepinmorestrengthwhereitjoinsthecasting.Thepinholeismadetwotothreemillimetersdeepwitha.027inchtwistdrill,usedintheslowspeedcontra-anglehandpiece.Thepositionofthepinholehavingalreadybeendeterminedandmarkedwiththe#4roundbur,theoperatorsimplyplacesthetwistdrillinthecountersinkandalignsitwiththepreparationforproperdraw.Thepinholeisthendrilled, being careful to not move your finger rest until the final depth has been reached. If more than one pin hole is to be made, the positions of all pin holes are first marked with the #4 round bur countersink. The .027 inch twist drill is placed in the first countersink and aligned with the prepara-tion draw, but no pin hole is made. Without changing the finger rest, or the angle of the twist drill, thetwistdrillisnowplacedinthenextcountersinkcheckedforalignment,andadjustedifrequired.Thisprocedureiscontinuedforallthecountersinksuntilacommonpathisdeterminedthatwillac-commodate all pin holes and draw with the preparation. Then without changing the finger rest, each pin hole is drilled. The finger rest and drill function like a surveyor, allowing the operator to place asmanypinholesasrequiredknowingtheywillallbeparallel.Thekeytothistechniqueistonotchange the finger rest until all the pin holes have been made. Theimpressionofthesepinholesiseasilymadebyplacingashortlengthof.025inchnylonbristle with a flat “nailhead” on the end, in each of the pin holes. Theimpression material subse-quentlyinjectedintothepreparationlocksontotheheadsofthebristles,andtheyareallwithdrawninperfectalignmentwhenthesetimpressionisremovedfromthemouth.Theimpressionisin-spectedforcompleteness,withatleast�mmofimpressionmaterialextendingbeyondallmargins,gentlywashedwithroomtemperaturewater,andpouredinalowexpansionstone.Oncethediehasbeenremovedfromtheimpression,an.024inchnylonbristleisinsertedintoeachpinhole.Thissizedifferentialwillallowthepinstoseateasierwhenthecastingisplacedinthetooth,andprovideroom for cement. The wax is flowed around the .024 inch nylon bristles and the wax up is carried to completion.Thenylonbristleswillburnoutcompletely,butmayrequirealongersoaktimeifthefinal burnout temperature is less than 950 Fahrenheit. The advantage of the Shooshan pins is they maybeeasilyplacedinrelativelyrestrictedareas.

4343

The Shooshan pins provide sufficient retention for an extensive inlay such as a large distal lingualinlayonamaxillarycuspid.However,ifthecastingwillrelyentirelyonitspinsforresis-tanceandretention,thenalargerpintypemaybedesirable.Inthiscase,thepinholelocationsaremarked with a #6 round bur countersink. The pin holes are then made with the same constant finger resttechnique,substitutinga169-Lor170-L(depending on size)tapered fissure bur for the twist drill. Theimpressionofthesepinholesismadedirectlywiththeimpressionmaterial,usingtheairventtechnique,asfollows.Thetipofadry27gaugeanestheticneedleisbrokenoffwithasmallplierinsuringthatthelumenremainsopen.Onesuchneedleispreparedforeachpinhole.Theneedlesareplacedtothedepthofthepinholes,andastheimpressionmaterialisforcedalongsidethe needles, the air in the bottom of the pin hole will flow out the hollow needle allowing the impres-sion material to completely fill the pin hole. The needle is then slowly withdrawn as more impres-sionmaterialisinjectedbesideit.Afterallneedleairventshavebeenremoved,theremainderofthepreparationisinjectedwithimpressionmaterialandtheimpressioniscompleted. Duringthewaxup,asize700taperedplasticpin*isplacedintoeachpinhole.Thewaxisthen carefully flowed around the protruding end of each plastic pin and down into the counter sink area.Thistechniquewillgiveamoresubstantialpinforuseinhigherstressapplications. There are times when even the 700 tapered fissure pin is not substantial enough, so a varia-tioncalledthe700 tapered fissure slot isused.Therearevariousapplicationsbutitmightbeusedin a distal occlusal inlay where there is insufficient tooth remaining in the isthmus area to provide agooddovetail.Ratherthancutanapproximalboxintheuntouchedtoothstructureofthemesialsurfacetokeepthecastingfrombeingdisplaceddistally,a�69-Lor�70-L(dependingonsize)burisusedtoplaceaslotinthepulpalwalljustinsidethemesialmarginalridge.Thisslotshouldextendbuccallinguallyabout2-3millimetersdependingonthesizeofthepreparation,andtoadepthof2.5millimeters.Thiswillprovideampleresistanceandretentionformaswellasallowingustoleavethemesialsurfaceofthetoothuntouched.Theslotthusformedisofrelativelylargedimension,andcaneasilybereproducedbyplacingthetipoftheimpressionsyringeinthebottomoftheslotastheimpressionmaterialisinjected,ortheneedletechniquecouldbeused.Afterthedieisrecoveredfrom the impression, trimmed, and lubricated, wax can be flowed directly into the slot with a small instrumentduringthefabricationofthewaxpattern.Thelargercrossectionalareaoftheslotshouldallow the wax pattern to be removed without breakage or distortion of the slot portion. The finished castings provide sufficient strength and retention without involving the remaining good approximal surface. Thefourthpintype,theTuckerpin,wasdevelopedbyDr.RichardV.TuckerinFerndale,Washington. In order to understand its use, one must first visualize a tooth which has suffered a great amount of destruction of the pulpal wall. This great void inside the tooth is filled with compos-itetoprovideabuildupyieldingoptimumdimensiontotheinternalofthecasting.

*Mfg. by N.W. Dental Supply, 590 Clearwater Suite C, Post Falls Idaho 83854 Concept by Dr. Maurice Chechik, Vancouver, British Columbia, Canada

4343 43

If the final preparation needs more resistance and retention form, a 7404 bur is used to place apinholetothefulldepthofthecompositebuildup.The7404burwhichismanufacturedwithafairly straight, rather than rounded profile**, works well for making this pin hole. When the impres-sionismade,thesyringeneedleairventtechniquedescribedpreviously,mayberequiredtoavoidtrappinganairbubbleinthedepthofthepinhole.Thepiniswaxeddirectlyonthedieasinthecase of the 700 tapered fissure slot. Before the casting is cemented in the tooth, the entire composite buildup is completely removed. This large internal void is then filled with zinc phosphate cement andthecasting,whichalsoiscoveredontheinternalsurfacewithcement,isseated.Thecementlocksintotheinternalofthetoothandatthesametime,locksaroundthe7404pin.Inthiswayweare able to get additional resistance and retention without sacrificing any additionaltoothstructure.Becauseofitslargesize,theTuckerpinisonlyplacedinthebuildupma-terial,andneverintoothstructure. Thiscompletessomeoptionsforincreasingresistanceandretentionformthroughthein-corporation of pins in our gold castings. A first choice would be the Shooshan pin because of its conservative nature. Secondly, the 700 tapered fissure pin would be chosen if additional strength is required. Thirdly, the 700 tapered fissure slot would be indicated where there are great demands to resist mesial or distal displacement, and finally, the Tucker pin could be used when more resistance and retention form is required and there is a buildup of sufficient volume to contain the pin. Incorporatingthesepintypesinyourcastingswillallowyoutoplacemoreconservativeandlongerlastingcastgoldrestorations.

Richard D. Tucker DDS private practice 1800 C st suite 226 Bellingham WA

Richard V. Tucker DDS private practice PO Box 1146 Ferndale WA

** Mfg. by Midwest Dental Products Corp. 901 W Oakton St., DesPlaines, IL 60018-1884

4545

Clinical Instruments and SuppliesRichardV.Tucker

HandInstruments(foronesetup)*2setupsfortheInstitutecourse.FrontsurfacemirrorCottonpliers#5explorer(Sutter)42Soffanglechisel(Sutter)43Soffanglechisel(Sutter)232Tuckergingivalmargintrimmer(Sutter)233Tuckergingivalmargintrimmer(Sutter)Chordpackinginstruments(2)CrownandbridgescissorsGoldstein�compositeinst.(Hufriedy)–placetemporarystopping

*Onlyforinternalbevel232gingivalmargintrimmer(Sutter)233gingivalmargintrimmer(Sutter)

*Onlyforsmallbicuspidsorcuspids44Soffanglechisel(Sutter)45Soffanglechisel(Sutter)*OneseteachoftheabovetwosetsisprobablyadequatefortheInstitutecourse.RubberDamDamholder(Young’sframeorWizard)Dam(extraheavy6x6dark)Lubricant(shavingcream)Dampunch,clampholderClamps:Ivorywithwings:�4,56,8A,2SeeRubberDamApplicationp.5�

HandpiecesHighspeedLowspeed-straight&contra-angleattachments

Burs(Brasseler)56, 57 straight fissure7404 finishing bur2,4,6roundbur35invertedcone860-0�2coursediamond

860-0�4coursediamond7404Midwest–potholesHeatlessstone(Mizzy)169L tapered fissureBuildupmaterialCompCore(chemicalcurecorepaste,white)Dycal

ImpressionGingivi-Pak#3-notbraided(Surgident)Hemodent–25%AluminumChloride(Pre mier)Lightbodypolyvinylsiloxaine–atleast4 cartridgesforInstituteCheckbitetrays(5):Coe72(3)andEmery(2)

Mixingpad,mixingspatula,impressiontips,syringeTemporariesDuraSeal(Reliance)Temporarystopping(Hygienic)Temporaries(crowns)Temporarycement

SeatingMoore discs (1/2”): med. garnet, fine sand, fine cuttleMoorediscs(3/8”)forsmallrestorationsMoorediscmandrels-straight&contraRibbedrubbercups#�00-5559HenryShein 800-372-4346Flourpumice#4(Dixon)Aluminumoxide-�5&�micron(Micro Abrasives)FlecksCement-yellow(Mizzy)Cementslab&spatulaGluma3�/4”diameterseatingsticks(orangewoodorchopsticks)Seatingmallet

4545 45

BasicItemsBibs&clip SuctiontipsSalivatipsTopicalanesthetic Anestheticsyringe,needlesAnestheticcarpulesCottonswabsDental floss2x2sCottonrollsCottonpelletsCottonrollholdersArticulatingpaperAutoclavebagsPatienthandmirror

4747

LaboratoryInstrumentsandSuppliesByRichardV.Tucker,DDS

Models*4simplehingearticulators*straightpins*debubblizer(Delarsurfactant)*smallbrush*dowelpins*mixingbowl*spatula*FugiRockdiestone(goldenbrown)*separatingmedium(NeyDieLube)*coping saw and fine blades*Parkerknife(#25blades)*die relief (Tru-fit,Geo. Taub.)*microfilm (Kerr)

Waxing inlaywax(Yetigrey)waxspatula(Clevedent#7)Roachcarver(SSWhite)Hollenbackcarverwaxinginstrument(P.K.Thomas3)*undercutwax

Investing&Casting*plasticsprues(Williams#10)*shortnosedpliers*Kleenex**stickywax*castingrings&sprueformers*wax ready made round shapes (Kerr #14)*asbestosliner*investment(Novocast)

*measuringvialforwater*distilledwater*porcelaincrucible*Gold(typeB)

Finishing*PrevoxTripolijewelersrougebristlebrushes(Buffalo#��,stiff&soft)ultrathinJoedandydiscsheatlessstonesdiscmandrels(Moore)mediumgarnetdisc(Moore)sand fine discs (Moore)cuttle fine discs (Moore)feltwheel&chamoiswheel&mandreltoothbrushbunsenburneroralcohollampmatches169 taper fissure bur#.5roundbur(straighthp)

*Itemsprovidedatthecourse

4747 47

SuppliersAccubiteDentalSupplyWOW articulators800-248-2746

AcculabScales (.01 g)800-656-4400

TheArgenCorporationCasting gold800-544-5525

BelledeSt.ClaireElectric waxer, die spacer800-322-6666

BlueDolphinProductsDowel pins800-448-8855

BrasselerBurs�-880-84�-4522

CTEnterprisesPin kits360-676-0305

CarolinaBiologicalSupplyAICl crystal, sodium nitrite, Scales, glassware800-334-555�

ColumbiaDentoformIvoreen teeth7�8-482-�569

DelarCorporationSurfactant800-669-7499

EmeryDentalSlim check bite trays800-637-66��

GCAmericaFugirock die stone 800-323-7063

JensenIndustriesCasting gold, gold foil, DVD800-243-2000

MDLDentalProductsWaxes206-824-3449E.C.MooreCoDisks and madrels�-800-33�-3548

MicroAbrasivesPolishing powders (aluminum oxide)�-800-426-6046

MoycoPolishing strips�-800-22�-�344

NorthwestDentalSupply700-701 Plastic pins800-842-2787

PepperDentalMicropol (rubber polishing points)888-4�89

Pfingst Twits drills (.6 &.9 mm)908-56�-6400

SuterDentalMfgHand instruments, sharpener�-800-368-837620%TuckerdiscountWhipmixNovocast investment800-625-565�

4949

EducationalMaterials

RichardV.TuckerDVDThisDVDcontainsallthreeofDr.Tucker’svideos:The Gold Inlay Basics for gold inlays and onlays that include preparations, impressions and finishing.Variations in Cavity DesignCoversmostofthepreparationsandvariationsthatDr.Tuckerteaches.The LaboratoryLabbasicsandproblemsolving.Amustseefordentists.

ThecostoftheDVDis$�50.Orderfrom: JensenIndustries �-800-243-2000Ext233 AskforAnnPellegrini

PlasticmodelsofTuckerpreparationsCopiesofpreparationscutbyRichardV.Tuckerforthevideo,VariationsinCavityDesign.Costis$�50persetof�4models.Orderfrom:

VodaDieReproduction 6800“K”Montgomery Albuquerque,NM87�09 (505)88�-8463

IvoreenteethPlastic teeth to practice cutting preparations. Upper and lower first molars and second bicuspids seemtobeanadequateselectionaswellassomeuppercuspids.Orderfrom:

ColumbiaDentoformCorporation LongIsland,NewYork (7�8)482-�569 Fax(7�8)482-�585

4949 49

stadium

Dental School

parking

Montlake Blvd

Pacific PlN E 45th

N E Pacific St

I-5

520

University of Washington Dental School

A

B

entrance

Patient parking off of Pacific Pl..

Enter hospital at the main enterance.

Walk down the hallway and turn left at D-wing.

Take the elevator to the 2nd floor..

Turn right off of the elevator..

University Hospital

N

Patient ParkingTake your parking ticket with youGet a discount stamp from your Dr.Pay at the booth

Tucker Institure June 19-23Clinical Sessions:Monday: 10 AM, 2:00 PMTuesday: 9:30 AM, 1:30 PMThursday: 9:30 AM, 1:30 PMFriday: 9:30 AM, 1:30 PM

Second floor clinic, D wing

D

5�5�

RubberDamApplicationDennisM.Miya,DDSSETUPDam, punch, clamp, frame, waxed floss, mirror, explorer, cotton pliers.

PUNCHINGUppers-Usedepthofthepunchasaguide(�inchinfromedge).Startatthecentral(centerofdam)andpunchtomolars.

Lowers-Dividethedamintothirds(vertically)andcenter(horizontally).Punchfor theclamponthemolar(center/thirdonsidetorestore)andcontinuetothecentral.Thespace betweenthepunchesshouldbeabout�.5-2mm.Thereshouldbeenoughrubberbetweenthe holesforadequatetissueretraction.Alwaysusethelargestholeonthepunchfortheclamp andthesmallestholeforthelowerincisors.

CLAMPSELECTION(Ivoryclampswithwings) Molars 14 standard workhorse clamp because it fits the most teeth. 56distalextendedbowgivesgoodaccessforrestoringsecondmolar. �4ad,8adusefuldistalextensionclampswhenrestoringthesecondmolar. 8aforsmallmolars.�4aforpartiallyeruptedmolars. Bicuspids2,0 Cuspids2

PLACEMENTAneasymethodistotakethedam,frame,andclamptoplaceasoneunit.Pickyourclampandpre-fit to the tooth if necessary. Attach the top of dam to the frame by placing tension between the toptwonibsandthenthebottomportionisattachedwithtensionbetweenthebottomtwonibs.Thisallowsplentyofplayinthedamwheretheclampwillbeattached.Attachtheclamptothedamandframeviathewingsontheclamp.Lookthroughtheholeintheclampandplace.Releasethedam over the wings with cotton pliers or an explorer. Stabilize the dam initially by flossing the front tooth first and then work back to the molars. The dam is tucked around the teeth resulting two layers ofdamaroundeachtooth.Thishelpsretractthetissueandsealthedamtominimizesaliva.Thetechniqueistoinvertthedamwithanexplorerortissuepackerwhilepullinggingivallyonthedam.Eachtoothissimultaneouslydriedwithairtofacilitatetheprocedure.Re-adjustthedamtotheframeasnecessary.

5�5� 5�

Basicsetup

Puncheddamforupperandlower

Dam,frameandclampasoneunit

Invertingdamaroundeachtooth

Dampunchtable

�4,56,8aclamps

Initialplacement

Completedrubberdamplacemnt

�”