cadcam article
TRANSCRIPT
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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
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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
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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
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{ 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
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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
les in s fhen rp l r tno lvmcr ized
o
af l tx
- ' " . , ' b , ' -
L h c e m p l a t e
n
p o s i t i o n
r r c u n e
z ) .
Theo l ien fa t i t - rn
f
fhe empla te s thcn
assessed uring
talking
and smiling.
F
GU RE 13. Ava lJent
u ler
le ing
t tached
o he
nraxi l la ryMD .
0.ffi0
Fl c U RE 15.Tceth e lect ionrokl abs
FIcURE 17. Lu l ingse lecter l tabwi th
lowal l leight-cured
cDmposi te
esin .
With
the mandible
stabil lzed n
j I s
c e l r i c
e l . r t i o no s i t i o n
y t h e
styJusengagrng
he
recess
n the
r r a c i n g l a t e ,
A v aD e n t r e g i s t r a L i o n
n r a t e r j r l
s n j c c L c d
n t o t h c
s p a c e
h t r l \ ^ / p e nh e m . r ' i l l e r v
a n d m . f n d r b U l a r
a r c l r e s
r r c u n E
a ) . f i s m p o r L a n t
h a f
I s p n e r o u s
l n r o r r n t
f
m a t e r i a l
e u s e
b ' " ' _ " * "
F
c U
RE 1
4. Deternr in ingheappr
pr ia le cc lusa l
lane
wi h AvaDcnl r i { ln ta t ionu ler .
F c U RE 1
6. Deternr in ingncisa l -cerv ica l
er rg th f c len lure
tocth s ing ld lenture .rsgu ic le .
F l G U R E
l S . l n j e c t i n g r e c o r i l i n g n a t e r i a l
o c a p t u r e
cen l r ice la t ion.
so i l f lows ; t round
rhe Lr , rc ing
l r l . r fe
, . , r - r . . r , , - . . r r ; - * r , . . . l . r c l t e s
L h e
r r r u r r 1 1 r r 1 /
cr L
r n r r i l l r r ' , . ' . , . 1 " - . l i l . " l e r
f \ N / lD r r , r r