cadcam article

7/24/2019 CADCAM Article

1/10

C D A J O U R N A L

v o L 4 1 ,

N o 6

CAD/CAM

omplete

Dentures:Review

of

Two

Commercial

Fabricationystems

M A T H E W . K A T T A D I Y I L, D 5 ,M D S ,

M S ; C H A R L E S .

G O O D A C R E ,

D 5 ,M S D ,M S ;

A N D N A D I MZ , B A B A ,

D M D ,M 5 D

ABsrRAcrThe se f computer-aided

esignnd omputer-aided

anufacturing

(CAD/CAM)

as

ecome vailableor complete

entureshrough

heAvaDent

nd

Dentca ystems.

vaDentses aser cann ing

nd omputer

echnology.

eeth re

arranged

ndbases

ormed

sing

roprietary

oftware.

he

bases remitled

rom

prepolymerizeducks f resin. entca

ses omputeroftware

o

produce

irtual

maxi[ [arynd

mandibulardentulous

idges,rrangehe

eeth nd orm

bases.he

denturesre

abricatedsing conventionaI

rocessingechnique.

A U T H O R S

Mathew

T.Kattadiyil, os,

t"ros,"ts,s a diplornate

of heAmerican

oard

of Prosthodontics

and

ellow fthe

American ollege f

Prosthodontists.

e s

currentlyhedirector f

theAdvanced

pecialty

Educationrogramn

Prosthodonticst Loma

Linda niversity

chool

f

Dentistry.

Conftict f Interest

Disciosure:

one eported

Charles,Goodacre,

os ,

MsD, s, sa diplomate

oftheAmerican

oard

of Prosthodontics

and

ettow fthe

American

ollege f

Prosthodontists.e

iscurrently

rofessor

and ean t

Loma inda

University chooI f

Dentistry.

Conflict flnterest

Disclosure;

one eported.

Nadim

.

Baba,

uo,

r"rso,

s

a diplomate f

theAmerican oard

of Prosthodontics

and ellow fthe

American ollege

f

Prosthodontists.

e s

currently

rofessor

f

Restorative

entistry t

Loma inda niversity

School f Dentistry.

Conflict of lnterest

Disclosure; one eported,

nmnrr icr -e i r lp r l

r l ^ " i - -

" - r l

rqes

ucJ1511 arru

computer-aided

anufacturing

(CAD/CAM)

echnology

as

beenused

or the fabrication

of

inlays, rowns, ixed

partial

dentures,

mplant

abutments/prostheses

and

maxillofacial

rostheses.

AD

software

enders

he

geometrical hape

of anobject.CAM software irects he

fabrication

rocess.

Recently,

CAD/CAM

technology

has

becomecommercially

avaiiable

or

fabrication f complete entures

hrough

the ntroductionof AvaDentdigital

dentures

Global

Dental

Science LC,

Scottsdale,

riz.)

and

he DentcaCAD/

CAM system

Dentca

nc.,LosAngeles).

Insteadof a five-appointmen t

rocess

usedwith conventionallv

abricated

complete entures,

he CAD/CAM

systems sea two-appointmen t

echnique

whereby

mpressions,

nterocclusal

records nd ooth

selection anbe

completed

n one appointment,

The

denturesare

hen fabricatedusing

CAD/

CAM

technology nd

placed t the second

appointment.

TheCAD/CAMprocess ffers

significant

advantageso the

dental

practitionerand he

patient,Becauset

is

possible o recordall the clinical

data

in one

appointment

one

o

two hours),

chair

ime is reducedconsiderably,

hereby

providing

he opportunity

or a more

cost-effective

et of appropriately

accurate

complete entures.

repository f

digital data

remainsavailable hat

allows

for more

apid abrication f a spare

- , u r . r ro r s 407


2/10

dr:nture,

a replacement

denture

or

even

a

radiograplric

or surgical

template

that

aids

in

the

plar:rning

and

placement

of den[a]

implants

in the

future.

Additionally,

because

he

digital

data

is associated

witl-r

a specificpractitioner,

it is

more

1ike1y

that patients

wil l return

to

the dentist

who Fabricated

heir first

digitaJ

dentur:e

when future

treatment

is needed.

A review

of

recent literature

reveals

mul t ipJe

cpor [s

where

compute

-a ided

technology

was used

n the

f.abrlcation

f

comple f

< lcn

urcs .

The

ac tua lprocess

l

compuic r -a idcd

es ign ing

as nc ludcd

laser

scanning'

of delinitive impressions

or previous

dentures,'

as

wel.l

as he use

of

cone

beam

compu[erized

omography

(CBCT)

of mod i f i

d

ex is l i rg

c len

ures . ,

Th

e compLlter-aided

manufacturing

process

has

uti l jzcd

lascr l i thography,

computer

numerical

control

(CNC)

mill ing

techniques,'

efined

versions

of

the rapid prototyping

technique'r 'r i

nd

state-of-the-art

CNC techniques

hat

used five-axis

milling.3

Currently,

two

techniques

ar e

being

used

for

the

actual fabrication

of CAD/CAI\4 dentures. One process

(the

AvaDent

system)

uses

he

subtractive

technique

of mil l ing

a

denture

base

rom

a

prepo lymer ized

"puck"

of

denture

base resin

and the

otJrerprocess

the

Dentca

system)

uses

an additive

technique

whereby

rapid

pro io typ ing

(s ie reo l i thogr :aphy)

s

used

Lo orm

a t r ia l

den lur -e ,

f reques ied

by

the

dentist.

The

definitive

denture

is

processed

conventlonally.

4 0 8 rL r r

, . : r ,r

F

c U R E 2.

Putty

astcfeated

y adaptation

o the

old

maxi l la ry

lenture .

Reporting

the

"first

proof-of-

concept"

for

the clinical

fabrication

and placement

of CAD/CAM

complete

dentures

in

a

patient

and

describing

clinical

methods

used

to acquire

he

necessary

morphoJogical

ata,

Goodacre

et a1." r:edicted,

[W]hen

the CAD/CAM

Lechrrology

or

fabricating

complefe

dentures

becomes

commercially

available,

jt

wil l be possible

o scan

he

denture

base

morphology

and tooth positi ons

recorded

with this

technique

and impor:t

those

data

into

a virtual

tooth

arrangement

program

where

teeth

can be

articulated

and then

cxpor i the data o a mi l l ingdev ice or the

fabrlcation

of the complete

dentures."

Wi th

the

ntroduc t ion

of

commcrc ia l ly

ava j lab le

AD/CAM

denture

ys fems

such

as AvaDent

and Dentca,

the era

of

digital

complete

dentures

has

arrived.

The

purpose

of

this

article s

to

describe

he

procedures

associated

with

the AvaDent

and Dentca

systems.

The

AvaDent

digital

denLure rocess

involves

the

following

two

appolnrments:

r. Impressions, aw relation records,

occlusal

plane

orientatlon,

tooth

mold

and

shade

selectlon

and maxillary

anterior

tooth positioning

record;

and

z. Placement

of the

dentures.

: '

The

AvaDent

ystem

ncludes

kit

of

all

the required

materials

and devices

o

complete

the

two-appointment

clinical

p rocess

r rcune

).

(

D A

J O I ] R N A I ,

V O I

4 I , N O

F GUR

E

g.

Selected

vaDent

tock

ayand

maxillary

putty

ast.

t ' 1 . 1 ' : ' I

,

: ,

i , ' l ' ;

Theprocedure tartswith fabrication

of a

putt.y

cast

ormed

by

pressing

mixed

poly(viny1

iloxane) utty

into

the

intagl io

r- r r face

f

he

par ient 's

x isLing

dentures

rrcune

).

f these

entures

areunacceptable

r unavailable,

hen

diagnosfic

asts

anbc generated

rom

a

prelimirrary

mpression.

F rcuRE

shows

he he rmop l as t i c

tray

selcct. ion

or

the maxil lary

rch.

The

ray s

sof rened

y mnrersing

t i n

a waterbath

set

at Bo'

C

(r7o'

F)

or

approximately

ne

minute

and

adapting

the tray o the putty castby pressinghe

materiaI

nto

contact

with the

castor

stretching

he material

o cover

equire

areas. he

aclapted

rays

can

hen

be

adjustecl-rsing

crylic

esin

burs o

remove

verextended

reas.

After:

he trays

have

been

adapted

on theputty

cast, hey

are

placed

n

th e

patient's

mouth

to determine

f there

are

areas

f overextension

r

underextension

and adjustments

re

made

asneeded.

t is

lmpor:tant

hat

the maxillary

ray extends

posteriorly

o

cover he

area

of the

vibrating ine and he pterygomaxil lary

fissures

hamular

notches).

t

is als


3/10

F G

U

RE

4. Maxillaryand

andibulardefinitive

impressions,

tuberosities

o locate

he

pterygom

axillary

fissures. etermining

he extension

f the

mandibular ray requires

visually ocating

the retromolarpads

and reflecting

he

cheekso locate

he extent

of the buccal

shelves.

Evaluation

of the retromylohyoid

areas equires

placing

he head

of a

dentalmirror

into

theseareas

nd asking

the

patient

o wet his,/her

ips

with

his/

her

ongue o

determine

he degree

f

displacement

f the mirror

by the tongue

musculature.

M

aki np,Maxi

I a y ttn

d

Ma

ndibuLar

I) e

ini

tiv

e rnp

e s ons

After

customizing

he mpression

trays and confirming

appropriate

coverage

andadaptation

n the

patient's

mouth,

tissue

topsshould

be added

o the trays.

After

applying he

appropriate

adhesive,

AvaDent

egistration

s applied

s our

dabs o distributed

areas

on the maxillary

tray

and three

areason the mandibular

tray. The

rays

are hen seated

n the

patient's

mouth

and oriented

so he

trays

arenot

pressed

nto

contactwith

the

soft tissue,

hereby eaving

pace

for the subsequentordermoldingand

light-body

wash mpression

material.

TheAvaDent

border

molding mpression

material s

used o

bordermold

the

maxillary

and mandibular

rays

employing

the method

usedwith

conventional

cusrom rays.

The

border-molded

rays

are nspected.

If

thereareareas

where he

tray has

contactedhe

mucosa,

heseareas

re

removed sing

an acrylic esin

bur. f there

F GURE

S, MaxillaryMD howing

renchsed

o

move

the

djustableip

upportlange,

aredefectsn

the bordermolding,

adhesive

is

applied o

theseareas nd

additional

border

molding

materialapplied

o he

border

molding

canbe refined

n those

areas.

Definitive

mpressions

f the maxillary

and mandibular

arches

remadeusing

he

AvaDent

ight-bodypoly(vinyl

siloxane)

impression

material

rrcune

+).Because

there

s no

pol;rmerization

hrinkage

of

the

denture ase,

ecauset is

milled rom

prepolymerized

esin,

posteriorpalatal

seals

renot always

needed,

nless here

is considerable

oveableissue resent

in

the

posterior

palateand over he

edentulous

idges.

When

a

posterior alatal

ea l

is needed,

he

areaof coverages

identif ied

by marking

he vibrating

Iine and

the areas ocated

anteriorly

where

he seal

anbe

posit ioned

ased

on the

areas f

compressibil ity

nd

the depth

to

which

the

tissuecan be

compressed

n these

areas. hese reas

aremarked

and

then transferred o

the

impression.

he

radit ionalmethod

of

scoring

he definitive

maxillary

cast o

establish he posterior palatalsealarea

is not

usedwith

CAD/CAM maxillary

dentures

ecause

here s no

physical

cast.Wax

can be applied

o the areas

of

the mpression

where

a

posterior

palatal

eal s

needed nd

he wax

built

to a height

hat corresponds

o

the desired

epth

of the compressible

tissue.

t is

proposed

hat the height

of

the

waxbe one-half

r lessof

the tissue

compressibil ity

epth.

C D A . ] O U R N A L ,

V O L 4 ] , N O 6

F c

U

RE

6. MandibularA[y'D

ith racing

late

nd

maxitlarv

MDwith tvlus,

Jaw Relq.tion

Records

TheAvaDent

denture

echnique

ses

an anatomicalmeasuring

device

AMD)

that canbe adjusted

o the

desired

occlusal ertical

dimension

OVD)

and

then used

o maintain

hat dimension

while centric

elation s recorded

sing

he

incorporated othic

arch

racing

plate

and

stylus.TheAMD

is alsoused

o determine

the correct

amount of upper ip

support,

the

position

of the maxillarysix

anterior

teeth and he desired

mediolateral

orientationof the

occlusal

lane.

The

AMD

consists f

a

maxillary

ray

with a

centrallyocated djustable tylusand an

adjustableip support

lange

rrcunr

s)

and a mandibular

ray with

a

flat

occlusai

tracing

late

rrcune

e). n

addition,here

is an occlusal lane

orientation

uler that

canbe nserted

nto the maxillary

AMD

and used

o record he

alignmentof the

maxillary

AMD with

the interpupillary

Iine so hat

the computer rogram

will be

able o align

the maxillary

teeth with the

in l -prnr rn i l l e r r r l inp

The maxillary

AMD is coated

with

adhesive

hen covered

ith AvaDent

registration aterial rrcunez). t is then

seated

o record he ridge

morphology

of

the maxillary

archas

well as he

portion

of the

palate

overed y the AMD.

There

shouldbe suffrcient

material

o stabilize

the tray or the process

hould

be repeated.

The mandibular

ftay

with

the

recordingplate

s then coated

with

adhesive

nd

illed

with

the

recording

material

so t canbe seated

n the

patient's

mouth.

Careshould

be taken

r u N e o r a

4 0 9


4/10

{ I ) i 1 0 t r l t i l i l

Fl c URE

7.

N4axi l la fyAf4D

l lec lwi th

recofding

ma erial.

t l-rat

he

maxil lary

and mandibular

AMDs

arc

l tos i t ioncd

so

thaf

they

are

fair ly

parallel

o

each

other

and the

maxil lary

stylus

is located

over the

anterior

aspect

of the

manclibular

AM D

t r a c i r r g l a t e

r r c u n e

e ) , o r

t h e p r o c e s s

should

be

r:epeated.

The

occlusal

vertical

dimension

is

de lc rmincd.

f

the cx is t ing

dentures

provide

an

appropriate

occlusal

vertical

dirnension,

hey

can be

used

to record

thr :

distance

between

marks

on the

face

when

the

dentures

are n

occlusal

contact. ] f not, use conventlonal

methods

to

determine

the

desired

dimension,

The

rest

vertical

dimension,

speech,

onicity

of

the musculature,

facralproportions

and biofeedback

can

be

usecl

o confirm

appropriate

occ lusa l

er : t i ca l

imens ion

r rcune

e) .

The adjustable

screw n

the

maxil lary

tray

is turned

clockwise

o

extencl

he

stylus,

or

counterclockwise

o retract

the stylus

so

it contacts

he mandibular

410

r r

r

. r , r,

F

GU RE

8. Maxi l la ry

nd and ibu lar

MDplacecl

a i r

y

par

l le {

o each theL

ir :acing late at the appropriate vertical

d imens ion

r

rcu ne

r o ) .

Once

he ver t ica l

dirnension

has been

established,

he

adjustable

screw

n

the

maxil lary

AM D

is

uscd

to

ex tend

or re t racL

hc

upper

ip

support

flange

so

it provldes

appropriate

l ip

suppor t .

The pat jen t

s g iven

an

oppor tun i ty

lo assess

he

ad jusLrnenLs

by

viewing

his or

her l ips

in

a mirror.

Recording

centr ic

relatior-r

s

accomplished

by making

an intraoral

gothic

arch recording.

While

the

stylus

on

the

maxil lary

AMD

ca n

produce markings on the mandibular

plate

when

jaw

movements

are

made,

i t

is helpful

to

place

a marking

medium

on

the tracing

plate

by either

rubbing

artlculatlng

paper

over

the

plate

or

spraying

the plate

with

an

aerosol

marking

medium.

The gothic

arch

rac ing

s made

by

ins t ruc t ing

the patient

to

move his,/her

ower

jaw

forward

and

backward

while

maintaining

contact

between

the

F I c U R E

l 2 . S t y l u s s e a t e c l i n

h e r e c e s s c r e a t e d a t

h e a p e

of

thegoth ic

rch ecorc l ing .

maxil ary stylus and the mandibu]ar

AMD

trac ing

p la te .

The pat ien t

i s

then instructed

to move

his/her

jaw

to one

side, making

a lateral

excursive

movement

from

the

centr ic

relation

positlon,

and

then

to the

contralateral

slde.

The

stylus

on the

rnaxil lary

tray

scribes

ines

on

the mandlbular

r:ecording

late,

and if

the

process

s

done

correctly,

an

arrow point

or gothic

arch recording

should

be

clearly

seen

( r r

cune

r r ) . The

apex

of

the record ing

denotes

he centr ic

relation

positiorr.

A

recesss then made n Lhe rac ingp la ie

tha t rpprox in rares

he

t jp

d iamefer

oF

the stylus

at

the apex

of the

gothic

arch

arrowpoint

using

an approprlately

sized

round

bur or

acrylic

resin

bur,

and the

mandibular

tray is reinserted

in

the

patient's

mouth.

The patient

can

then

move

his/her

mandible

or be guided

to

the pos i t ion

where

Lhe

max iJ la ry

ty lus

engages

he

recess

o as

o maintain

the

centr ic

e la t ion

pos i t ion

( r rcune

rz ) .

F I G U R E

9. Eva lua l ing

cclusa l

er t ica l

l inension.

F T G U R E

o . O c c l u s a l v e r t i c a l c l i n e n s i o n b e i n q a d i u s t e d .

1 . Gothic

rch ecorcling


5/10

To record

he occlusal lane

orienl,atio n, he AvaDent

ruler rs

nsert.ed

il-r l-re naxil laryAMD

(rrcune

ra)

anrl

the anterior

acljustable ortion

movec[

u r t l i l t i s , r l i p , n c d

l ) , 1 r ' l ] l t ' l

o

l r t '

r t r , r g r l . r r y

i r t

' r l ) r

l ) i l l . r ' y t t ' t , r

n , ' t ng

t

r t , u r

c rs

o f

ther

up i ls

o1 ' the

yes

r rcunr

r+ ) .

' lhe

angJes noted

ancl ccorded

on the

laboratory

work authorization

orm. Ihis

wil l assist he rnanufacturer

n

orientlng

tl're

medlolatcral

occlr-rsallanc

so it

para11e1s

he

interpr,rpillary

1lnc.

TtLe ext pr:ocedure

n

t1-risirst

appointment is

to mark

the lridline or-t

fhc 1ip support

flange

as well as tlre smile

lir-re or

the naxillary

antel.ior

teeth based

or r

l recurv l t r rc

o l t l tc c rwcr ip

r lu r ing

smiling.

he :;ize

of the maxil lary

anterior

lcc fh s

dcLe l ln incd

y ovc r lay ing

l rc

l l r r c c

v ; r i l e b l t :t , r , t l r

i z cL t ' r n | l a t c sr n l t t '

teetlr n

thc existing

denture,asisr-Lming

the

existing lcnture

tooth size s

desjrable

t o

t 1 - r e

a t i e n t

r r c unes

s n N o o ) .

f

not, the

tootJr en'rplate

s selected

ha t

tn , r tc f tcsl rc r r r t i c r r l ' c os i rcd

oo l l t

j ze .

ln

addition, by

overlaying the maxiJlar :y

f o o l l t l e m r l l , r t ' c s n l l r l n x i s f i n o d p r r l r r r o

the

position

of

tio

pink

clenture

as e

resin

around tl-re

necks o1 1-re

eeth car-r

be selected rom

the tl-rree r-rmbereil

loca fons pr r 's i { 'n

or r hc too fh

t .empl . tt ' .

fb serve

as a guicle

dur:ing der-rture

fabrication, l owablecontposite esin

is applied

o the nside

of the selecteil

tooth mold

ternplate.

ll're

tooth mold

f e m n l . l l e i s l l r l n r r n s i l i n n e d r r r , . f , , l l r r , r r r o t

t h c m i d l j n e n d

s r r r i l ci n cm a r k i r r g s

nd

placecl

n the

exact ocation

where ther

denture teeth

should be arranged.

The

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assessed uring

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A v aD e n t r e g i s t r a L i o n

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4. Deternr in ingheappr

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er rg th f c len lure

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so i l f lows ; t round

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cr L

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