113B Selective Grinding Review

113B:CompleteDentures

Deflasking,Remounting,andSelectivelyGrindingCompressionMoldedCompleteDentures.

StudyReviewGuide

Reference:“YellowAFP;pgs95‐106”

1.Theobjectiveofthedeflaskingprocedureistoremovethedenturefromtheinvestmentmaterialwithout:

a.breakingthedenture

b.exposingthedenturetoleftovermonomer

c.dislodgingthedenturefromthecast

d.exposingthepolymerizedacrylicresintooxygen

ANSWER=AandC

2.Thedentureflaskanditscontentsshouldbekeptat_____________°Fbeforedeflasking.

a.100 b.70 c.roomtemperature d.60

ANSWER=C

3.Theequipmentneededtodeflaskadentureincludes:

a.Plasterknife b.twochisels c.waxspatula d.plastersaw

e.flaskejectorunit

ANSWER=A,B,D,E

4.Arrangethestepsfordeflaskingadentureintotheircorrectorder.

a.Usinginwardanddownwardpressure,applyforceuntiltheflaskhalves comeapart

b.Makesuretheflaskiscool

c.Placeflaskintheejectorunit

d.Closetheunitandpassthechiselsthroughtheholesinthesidesofthe ejectorintotheslotsbetweenthetwohalvesoftheflask

e.Removelidofflaskwithplasterknife

ANSWER=B,E,C,D,A

5.TorF:_____Chiselsactaslevers,andthesidesoftheejectorasfulcrums,makingitquiteeasytoseparatethemoldfromtheflask.

ANSWER=TRUE(givemealeverlongenough,andapropstrong enough,andIcansingle‐handedlymovetheworld….Archimedes)

6.Whenthedentureflaskisplacedintotheejectorunit,theknockoutplateshouldbe:

a.faceup

b.facedown

c.beremovedfirst

d.hitwithahammerlightlyfirst

ANSWER=A

7.Arrangethestepsforremovingadenturecastfromtheinvestmentmoldintotheircorrectorder.

e.Pryofftheocclusioncaptoexposingthecusptipsandincisaledgesofthe dentureteeth.

d.Inspecificareas,cuttheouterwallsofthestonemoldwithaplastersaw.

b.Prythesectionedstonemoldawayfromthefacialsurfacesofthedenture withaplasterknife.

a.Trimstoneawayfromlingualareasofanteriorteeth.

f.Takeoutinnersectionsofthemaxillaryandmandibularmold.

g.removealldebrisfromindexinggroovesandbaseofthecast.

.ccleanawayanyremainingplasticbubblesorstoneresiduefromthe dentureteeth.

ANSWER=E,D,B,A,F,G,C

8.TorF:_____Sawcutsshouldbemadeintheareasaroundthecanines,takingcarenottosawintothedenture.

ANSWER=TRUE

9.TorF:_____Trimmingstoneawayfromthelingualportionofanteriordentureteethbefore removingexcessinnerstonepreventsthepossibilityofthedenturesnappinginhalf.

ANSWER=FALSE(ithelpsreducethepossibilityofthedenturelifing offthecastwhentheinnerportionofthemoldisremoved).

10.Afterdeflasking,ifthereisanyevidencethatthedenturehascomeloosefromthecast,thelabtechmust:

a.reflaskdirectlytofinalclose

b.notifythedentistthattheoperationhasfailedandmustberestarted.

c.askthedentistifthecaseshouldberemountedontothearticulator

d.usearticulatingpapertodeterminehighspots,andaddmethyl methacrylatetocorrectthediscrepancy.

e.proceedasnormal,becauseshiftingofthedentureonthecastisnormal afterprocessing,andiseasilycorrectedduringfinishing.

ANSWER=C

11.TorF:_____Denturesshouldnotbeshellblastedduringthedeflaskingprocedure.

ANSWER=TRUE

12.Shellblastingadentureonthecastcancause:

a.Thedenturetobeliftedfromthecast

b.Shellfragmentstolodgebetweenthedentuereandthecast

c.thedenturetonotfitonthecastrightagain,makingproperfitimpossible.

d.thedenturetosplitinhalf,orabradedentureteethsoquicklytheylose function

ANSWER=A,B,C,

13.TorF:_____Remountingandselectivegrindingcorrectscontactrelationchangesindentureteeththatmayhaveoccurredduringprocessing.

ANSWER=TRUE

14.Themostcommonchangethatoccurswithcompressionmolded,heat‐cureddenturesis:

a.lateraltoothshift

b.toothaxialshift(twisting)

c.lossofcurveofWilson

d.lossofVDO

ANSWER=D

15.IncreasesinVDOintherangeof______mmto______mmareacceptable.

ANSWER=0.25to0.5

16.Twocommonchangesincontactrelationofdentureteeththatcanoccurduringprocessingare(listthem):

_________________________________ _________________________________

ANSWER=ChangeinVDO,Toothshifting

17.Circleallthatapply.Reasonsthatdentureteethmayshiftinpositioninclude:

a.Baseplatewaxisunstable,anddentureteethcandrifteasilyintrial denture.

b.Settingexpansionofthestoneusedtoflaskthewaxdenture.

c.Notremovingexcessstoneinincisalareasofdentureteethafterdeflasking.

d.Resinpackingpressuresduringtrialpacksandfinalclose

e.Duringpolymerization,theresinexpandsandcontracts,possiblymoving teeth.

ANSWER=A,B,D,E

18.TorF:_____Acrylicresindoughexpandswhenitisheated,andcontractswhenitiscooled.

ANSWER=TRUE

19.Whenrearticulatingadenture,retentiongroovesshouldbecarvedwitha:

a.cutoffdisc b.heatlessstonec.84‐Tbur d.rubberwheel

ANSWER=A

20.Retentiongroovesshouldbeplacedonto______________areasofthecast:

a.rightandleftbuccal,anterior,andposterior

b.posteriorandanterioronly

c.continuouslinesaroundthebody

d.rightandleftbuccal,andposterioronly

ANSWER=A

21.Beforerearticulatingadenture,thebottomofthecastand_______________mustbecompletelycleanandfreeofdebris.

ANSWER=IndexKeys.

22.TorF:_____Whilerearticulatingadenture,totalcontactbetweenthecastandthemountingmustbeachieved.

ANSWER=TRUE

23.Itisnotagoodideatocovertheentirejunctionlineofadenture/mountingwhenrearticulatingthedenturebecause:

a.itwillformapermanentseal,andtheonlywaytobreakitistobreakthe dentureormounting.

b.itwillsecurethemountingtothedenturetootightly,allowingnocushion forcheckingtheteeth,whichcancausethedentureteethtobecomeloose

c.itwillmaskthejunctionline,andyouwillnotbeabletotellifthedenture isfirmlyseatedagainstthemounting

d.noneoftheabove,becausetheentirejunctionlineshouldbecovered.

ANSWER=C

24.Theobjectiveofselectivegrindingadentureisto:

a.reducethecuspanglestomoreacceptablelevels

b.increasethedepthofthefossa’s

c.addanatomyforesthetics

d.eliminateprematuretoothcontactsinawiderangeofjawmovements.

ANSWER=D[fromthebook,pg98,b:Theobjectiveofselectively grindingcompletedenturesforbalanceistoeliminatepremature toothcontacts(interferences)thatpreventmultiple,welldistributed pointsofcontactbetweenupperandlowerteeth,inanteriorand posteriorareas,ontherightandleft,duringworking,balancing,and protrusiveocclusion]

25.Listthreetypesoftoothinterferencesthatmaybepresentonacompletedenturepriortoselectivegrinding.

______________________________________________

______________________________________________

______________________________________________

ANSWER=highspots,deflectivecontacts,prematurities

26.Matchthetypeofinterfacewiththetypeofmarkitwillleavewhenarticulatingpaperisusedontheocclusalsurface.

TYPEOFCONTACT MARKSLEFTBYARTICULATINGPAPER

a.propercontact i.whitespotssurroundedby carbonringsor“donuts”.

b.lightcontact ii.Asingledarkspotonthetooth

c.contacttoostrong iii.Afaintsmudgeisleftontheteeth

ANSWER=(a–ii);(b–iii);(c–i)

27.TorF:_____whenadentureisproperlybalanced,markswillrevealthemselvesassoliddarkspotsinallareasofcontact.

ANSWER=TRUE

28.Fromthelistbelow,choosetheequipmentandmaterialsthatarerecommendedforselectivegrindingoperations.

a.blackandredarticulatingpaper(thethinnestavailable)

b.engineandhandpiece

c.hand‐heldwaxcarvingtools

d.burnishingtools

e.mountedstonesanddiamondsforthestraighthandpiece.

f.millingpaste

ANSWER=A,B,E,F

29.The_____________________burattachmentisespeciallyrecommendedforselectivegrindingoperations.

a.84‐T b.margintrimming. c.#6balldiamondd.½round

ANSWER=C

30.Themajorproceduresforselectivegrindingoperationsare(circleallthatapply):

a.correcttheVDO

b.restoreCO

c.correctworkingandbalancingocclusion

d.correctprotrusiveocclusion

e.mill‐inthedentures

ANSWER=AthruE

31.Beforeattemptinganycorrections,youmustmakesurethereadingsonthearticulatorarethesameaswhenthedentureteethweresetinwax,includingmakingsurethatthe______________________________andthe_______________________areproperlyplaced.

ANSWER=condylarelements/incisalguidepin.

32.TorF:_____Beforemakingselectivegrindingadjustments,theincisalguidepinshouldbeinthesamesettingaswhenthecasewasfinallywaxed.

ANSWER=TRUE

33.TorF:_______bulkgrindingonseveralteethtore‐establishthecompensatingcurveisacceptable.

ANSWER=FALSE(Onlygrindonanisolatedtooththathasclearly migratedoutofline.Donotgrindonseveralteethjustto“touchup” yourcompensatingcurve.)

34.Inasetofcompletedentures,apinopeningof______mmisthelimitofreasonableacceptability.

ANSWER=1mm

35.Inasinglecompletedenture,apinopeningof_______mmisthelimitofreasonableacceptability.

ANSWER=0.5mm(halfthatofasetofdentures)

36.If2mmofincisalpinopeningispresentandisolatedmigrationofatoothisnotresponsibleforit,youshould:

a.useselectivegrindingoperationstoclosethegaptoacceptablelimits.

b.useafinecuttingdisktoremove1mmofacrylicfromthedenturebase, thenre‐processthedenturetorepairyourcut.

c.notifythedentistthatthepatientneedstocomebackinforpreliminary impressions.

d.Donotproceeduntilyouconsultthedentist.

ANSWER=D

37.Whendeepeningsurfacesmarkedbyarticulatingpaperoppositestampcusps,youshould:

a.useblackarticulatingpapertomarkthehighspotsontheleftandright sides

b.tapthedenturetogethergently

c.useredarticulatingpaperformarkinghighspots,notblack

d.Makecorrectionsbygrindingstampcuspsonly

e.beingcarefultonotgrindstampcusptips.

ANSWER=A,B,E

38.Whendeepeningsurfacesmarkedbyarticulatingpaperoppositestampcusps,itisacceptabletogrindon______________________,__________________________and

__________________________________.

ANSWER=fossae,proximalmarginalridges,cuspinclines.

39.Whentheincisalguidepinistouchingthetable,andtherearemultiple,evenlydistributedpointsofcontactbetweenMAXandMANDteeth,youhaverestored:

a.VerticalDimensionofOcclusion(VDO)

b.CentricOcclusion(CO)

c.CentricRelation(CR)

d.Facebowreplicationposition

ANSWER=B

40.Incompletedentures,thecuspto__________________approachtocuspplacementistypicallyused.

ANSWER=“occlusalembrasure”

41.Occasionally,contactsbetweenopposinganteriorteethdevelopduringcorrectionofverticalprocessingerrors.Whenthisoccurs,itisbesttoselectivelygrindthe_________________________________________________________________________________asneeded,untilproperfunctionisrestored.

a.facioincisalsurfacesoftheMAXanteriors

b.linguoincisalsurfacesoftheMAXanteriors

c.linguoincisalsurfacesofMANDanteriors

d.facioincisalsurfacesofMANDanteriors.

e.Noneoftheabove,anteriorteethshouldNEVERbeexposedtogrinding (forestheticspurposes)

ANSWER=D

42.Thereare________pathsoftravelpossiblewhennewlyremounteddenturesaremovedintoworkingandbalancingrelations.

ANSWER=2

43.The2pathsoftravelpossiblewhennewlyremounteddenturesaremovedintoworkingandbalancingrelationsare(circleallthatapply):

a.apathalongwhichtheupperandlowerteethmeshbest

b.apathgovernedbythewaythearticulatorsettingsguidetheupper memberthroughlateralmovements

c.apathalongthelingualsurfacesofMAXcaninescalledcanineguidance.

d.apathwhichcausesthemandibularanteriorstolock.

ANSWER=AandB

44.TorF:_____Afterremountingadenturetoanarticulator,gettingtheteethtomeshusingthe“toothguided”pathisareliablemethodforcorrectinginterferencesbetweendentureteethalongthatpath.

ANSWER=FALSE(accordingtothebook,itisanunreliablemethod)

45.TorF:_____Theonlywaytocorrectinterferencesbetweendentureteethistousethepaththatisdictatedbyarticulatorsettings.

ANSWER=TRUE

46.Theobjectiveofcorrectingworkingandbalancingocclusionisto:

_________________________________________________________________________________.

ANSWER=onceagainmakethetoothguidedlateralpathsandthe articulatorguidedlateralpathscoincide.

47.Whencheckingworkingandbalancingjawmovementsforadenture,itisimportanttoincorporate__________________.

ANSWER=Sideshift

48.TorF:_____RedarticulatingpaperisusedwhencheckingbalancingandworkingsidesofadenturebecauseitwillnotbeconfusedwiththeblackmarksleftwhenVDOandCOwerecorrected.

ANSWER=TRUE

49.TorF:_____Whencheckingtheworkingside,posteriorteethshouldnothaveanycontactcausebyworkingsidecollisions.

ANSWER=TRUE

50.IfAnteriorinterferenceispresent,youshouldgrindthe:

a.facioincisalsurfaceofloweranteriorsasneeded

b.lingualsurfaceofupperanteriorsasneeded

c.incisalsurfaceofloweranteriorsasneeded

d.facioincisalsurfaceofupperanteriorsasneeded

ANSWER=AorB

51.Whenworkingonthe__________________sideofadentureinalateralmovement,the________________ruleisused.

a.Balancing;BULL

b.Balancing;LUBL

c.Working;BULL

d.Working;LUBL

ANSWER=C

52.TorF:_____Grindingonthe“balancing”sideofadentureinalateralexcursionmovementwillhelpcorrecthighspotsontheworkingside,iftheBULLruleisfollowed.

ANSWER=FALSE(donotgrindonthebalancingsidebyapplyingthe BULLrule,onlytheworking.)

53.Whengrindingonacompletedenturetocorrectworking/balancingmovements,younoticesomeredmarksareleftbyarticulatingpaperandyoudecidethatselectivegrindingisneededontheworkingside.FollowingtheBULLrule,selectthechoicesbelowthatwouldbeacceptabletogrindon.(allteethareonworkingside)

a.MesiobuccalcuspoftheMAX1stmolar

b.MesiolingualcuspoftheMAND2ndmolar

c.DistolingualcuspofMAND3rdmolar

d.DistobuccalcuspofMAX3rdmolar

e.MesiobuccalcuspofMAX2ndmolar

f.MesiolingualcuspofMAX1stmolar

ANSWER=A,B,E,(whileCandDaretechnicallycorrectforthe BULLrule,don’tforgetthat3rdmolarsarenot reproducedincompletedentures)

54.Theonlycuspinclinesonthebalancingsideofacompletedenturethatarecandidatesforgrindingtocorrectworking/balancinginterferencesarethe:

a.inclinesandcusptipsassociatedwiththebuccalcuspsofthemandibular teeth

b.cuspinclinesonly(nocusptips)associatedwiththebuccalcuspsofthe mandibularteeth

c.cusptipsandinclinesassociatedwiththelingualcuspsofthemaxillary teeth

d.cuspinclinesonly(nocusptips)associatedwiththelingualcuspsofthe maxillaryteeth.

ANSWER=A(allotherredmarkingsshouldbedisregardedonthe balancingside.)

55.TorF:_____Workingandbalancingcorrectionsaredonetogether,soredarticulatingfilmshouldbeplacedonboththebalancingandworkingsidepriortocheckinglateralexcursion.

ANSWER=TRUE

56.Theworkingandbalancingsidesarecorrectwhen:

a.noredmarksareleftbyarticulatingpaper

b.numerous,welldistributedworkingandbalancingsidecontactsdevelop

c.redmarksareleftbyarticulatingfilmontheworkingside,butnoneare foundonthebalancing.

d.redmarksareleftbyarticulatingfilmonthebalancingside,butnoneare foundontheworking.

ANSWER=B

57.Thepracticallimitofalateralexcursiontestmovementis____________________.

a.cusptipcontact

b.cusptofossacontact

c.cusptocuspcontact

d.cuspridgecontact

ANSWER=D

58.ArrangethestepsforperformingaRIGHTlateralexcursionandselectivegrindingoperationsintotheircorrectorder.

a.Movethearticulatorintoarightlateralexcursion(rightsidebecomes workingside)

b.Selectivelygrinduntilpropercontactsareachieved.

c.Observemarksleftbyarticulatingfilm,BULLcuspsofworkingside,and buccalcuspsandinclinesofMANDteeth

d.PlaceredarticulatingpaperbetweenMAXandMANDteethonboththe rightandleftsides

e.Lockdowntherightcondylarelementandreleasetheleftonthe articulator

ANSWER=E,D,A,C,B

59.TorF:_____Tocorrectprotrusiveinterferences,itisimportanttogrindtheappropriateinclines,buttonotreducetheheightofanyofthecusps.

ANSWER=TRUE

60.Thepracticallimitofaprotrusiveexcursionis:

a.whentheincisorsareedgetoedge

b.whentheincisorsarejustshortofedgetoedgerelationship

c.theposteriorsarejustshortofcusptocusptiprelationship

d.theposteriorsaretouchingcusptocusptip

ANSWER=AandC

61.Contactbetweentheupperandloweranteriorswithnoposteriorcontactisachievedby:

a.grindingfacioincisalsurfacesofMANDincisors

b.grindinglingualsurfacesandincisaledgesofMAXanteriors

c.grindingfacialsurfacesofMAXanteriors

d.grindinglingualsurfacesofMANDanteriors.

ANSWER=AandB(Basalastresort)

62.JEOPARDYQUESTION:“Asalastresortforachievingcontactbetweenupperandloweranteriorswithnoposteriorcontact,itisacceptabletogrindonlingualsurfacesandincisaledgesoftheseteeth.”

___________________________________________?

ANSWER=Whataremaxillaryanteriorteeth?

63.Contactbetweentheupperandlowerposteriorteethwithnoanteriorcontactcanbeachievedby:

a.grindingdistalinclinesofMAXbuccalcusps

b.grindingprematuremesialinclinesonMANDlingualcusps

c.millingtheocclusionwherearticulatingpaperleavesmarks

d.asalastresort,millingfacioincisalsurfacesofMAXanteriors

ANSWER=AandB

64.Theprocessofcoveringtheocclusalsurfacesoftheteethwithabrasivepasteandwiththeteethincontact,rubbingoffanyremainingsmallinterfacesiscalled:

a.Occlusalselectivegrinding

b.Selectiveocclusalmilling

c.Milling‐intheocclusion

d.Grinding‐intheocclusion

ANSWER=C

65.Thereare_______varietiesofabrasivepasteavailableformillingoperations.

ANSWER=2(oneforporcelainteeth,theotherfor[acrylic?])

66.Arrangetheproceduresformilling‐intheocclusionintotheircorrectorder.

a.Placetheabrasivepasteontheocclusalsurfacesoftheteeth.

b.Raisetheincisalguidepinabovetheincisalguidetable

c.Releasecentriclockssotheuppermemberofthearticulatormovesfreely

d.FromCOposition,engageinprotrusivemovementsabout5times, returningtoCOeachtime.

e.Repeattheentireoperation3or4times.

f.FromCOposition,engageinrightandleftlateralmovementsabout5times foreachside,returningtoCOeachtime.

ANSWER=b,c,a,f,d,e

**Questions67‐??dealwithSelectivegrindingofMonoplaneCompleteDentures**

67.TorF:_____Theobjectiveinsettingteeth0°onamonoplaneistomakethemonoplaneasflataspossible.

ANSWER=TRUE

68.TorF:_____Theruleinselectivegrindingmonoplanedentureocclusionsistoistoflattentheocclusalplaneofonearchandthenadjusttheteethintheotherarchagainstthatstandard.

ANSWER=TRUE

69.TorF:_____Afterremountingacase,iftheincisalguidepindoesnottouchtheplate,youshouldconsultthedentistbeforeproceeding.

ANSWER=FALSE(Onlyifthepinisofftheplate>2mm)

70.TorF:_____Themandibulararchshouldbethefirstarchadjustedbecausethemandibularteetharealmostsetonaflatplane.

ANSWEER=TRUE

71.TorF:_____Teeththatdonotconformtothemonoplatecanbedetectedbyrubbingaflatglassplateacrosstheentirearchform.Theglasswillleaveglassoxidesonhighspots,markingthem.

ANSWER=FALSE(Aflataluminumplateshouldbeused,notaglass plate)

72.TorF:_____Highspotscanbereducedbyusingtheedgeofanabrasivewheelmountedinahandpiece.

ANSWER=TRUE

73.TorF:_____Oncetheocclusalplaneofthemandibulararchisflat,thearticulatershouldbelockedandthelowerarchshoultnotbetouchedagainforgrinding.

ANSWER=TRUE

74.Fordentureswithacrylicteeth,thedenturecanberemovedfromthearticulatorandtheocclusalsurfacesoftheteethcanbesandedagainstaglassslabwrappedin_________gritwetordrysandpaper..

a.300 b.320 c.350 d.375

ANSWER=B

75.TorF:_____WhengrindingMAXteethinadenture,highspotsarelocatedbyapplyingtwopiecesofarticulatingpaper,oneontherightandtheotherontheleft.

ANSWER=TRUE

76.TorF:_____GrindingonMaxillaryteethshouldbecontinueduntiltheincisalguidepintouchestheplate.

ANSWER=TRUE

77.Whengrindingahighspot,youshouldzeroinonthatareauntilnogrindingisrequiredonthatspot.

ANSWER=FALSE(Youshouldgrindalittlebitinthespots surroundingthehighpointtoavoidditchingandcreationofposterior verticaloverlap).

78.Inthediagramsbelow,determinewhereandhowthecontactisincorrect(whichtoothinthefigureistheproblem,contacttooheavyortoolittle),indicatewhatthemarkleftbythearticulatingpaperwouldlooklike(“donut”,soliddarkspot,orsmudge),anddescribewhereselectivegrindingwouldbestbeusedtocorrecttheproblem.(cuspincline,marginalridge,fossa,etc).Alldiagramsshowtheteethfromthelingualaspectoftherightside.(Answersaregivenaftereachsetoffigurequestions)

FigA

78A:Circlethecorrectanswer:ThecontactforFigAis:

a.tooheavy b.toolight c.correct e.can’tbedetermined

78B:Thesetofteethshowingincorrectcontact(s)toarethe:

a.2ndpremolars b.1stmolars c.2ndmolars d.tongue

78C:Basedonyouranswerfor78A,themarkleftbythearticulatingpaperwouldappeartobe(circlethecorrectanswer):

a. b. c. d.Nomarkswouldbeseen.

DonutDarkMarkLightMark

78D.Ifadjustmentisneeded,Thecorrectwaytoremedythisproblemusingselectivegrindingwouldbeto:

______________________________________________________________________________.

ANSWERS=(78A:A);(78B:B);(78C:A);(78D:SelectivelygrindintheMAND1molarfossa)

79. FigB

79A:Circlethecorrectanswer:ThecontactforFigBis:


79B:Thesetofteethshowingincorrectcontact(s)arethe:

a.2ndpremolars b.1stmolars c.2ndmolars d.none





______________________________________________________________________________.

ANSWERS=(79A:B);(79B:B);(79C:C);(79DgrindinthefossaoftheMAND2nd premolarandMAND2rdmolaruntilthecontactisclosedtothepointofbeing correct)

80: FigC

80A:Circlethecorrectanswer:ThecontactforFigBis:


80B:Thesetofteethshowingincorrectcontact(s)arethe:

a.2ndpremolars b.1stmolars c.2ndmolars d.none





______________________________________________________________________________.

ANSWERS=(80A:C);(80B:D);(80C:B);(80D:Noadjustmentneeded)

81.Inthediagrambelow,circletheareasthatwouldsignifyidealStampcuspplacementincentricocclusion.

81ANSWER=

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113B Selective Grinding Review