LETTERS TO THE JOURNAL

THE JOURNAL devotes th is section to com m ent by readers on top ics of current interest to dentistry. The m anaging ed itor reserves the righ t to edit all com m unications to fit available space and requires tha t all letters be signed. Printed com m unications do not necessarily reflect the opinion or official p o licy of the A ssociation. Y our pa rticipatio n in th is section is invited.

c a r e f u l a tt e n ti o n t o d e t a il, a n d fa ilu re

Dental econom ics ■ . . .

s tic k to th e t o o t h , n o t to th e r e s t o r a ­

o f b r id g e w o r k is a c o s t l y a n d d a m a g ­

ti o n . H o w e v e r , g o ld c a s t i n g s c a n b e

in g e x p e r i e n c e f o r th e p r a c t i t i o n e r .

c h e m ic a lly b o n d e d to p o ly c a r b o x y la te c e m e n t s b y c o a t i n g th e fit s u r f a c e o f

I f t he dent al p ro fe ssio n had

D r . A c h a r y a ’ s r e p ly is e x c e l l e n t b u t

p r o p e r l e a d e r s h i p , th e d e n t i s t w o u ld

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th e

n o t h a v e a llo w e d h i m s e lf t o b e rip p e d

I w o u ld lik e t o r a i s e . T h e b o n d in g in

m a te ly 2/x t h i c k . 4 T h i s w ill h e lp r e t e n ­

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h y d r o ly z e d in th e p r e s e n c e o f w a t e r to

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w h ic h p o s s e s s th e a d v a n t a g e s o f th e

th e p a t ie n t to c o m e o u t f in a n c ia lly b e t­

c e s s c o n t i n u e s , a s e u g e n o l is r e m o v e d

p o l y c a r b o x y l a t e s b u t a ls o h a v e e x c e l ­

t e r w h e n d e n tis ts p r a c t i c e a s a g r o u p .

b y w a t e r le a c h i n g , u n til th e m a tr i x is

le n t c r e e p r e s i s t a n c e . 2

. . . I m e a n w h e r e s e v e r a l d e n tis ts

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g r o u p to g e t h e r in s u f f ic ie n t n u m b e r to

d r o x i d e .1

in c lu d e a t l e a s t o n e m e m b e r o f e a c h s p e c ia lty ,

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A p p a re n tly

th e

s tr e n g th

z in c p h o s p h a te c e ­

m e n ts b u t n o t u n til t h e y c a n b e r e ­ p l a c e d w ith m a t e r i a l s o f c o m p a r a b l e

q u a n tity p u r c h a s i n g o f s u p p lie s , a n d

p r o p e r t ie s o f th e E B A

c o m p l e t e u tiliz a tio n o f p e r s o n n e l an d

a d e q u a t e , b u t a v ita l p r o p e r t y th a t is

e r t i e s th a t a r e n e e d e d f o r e x t e n s i v e

e q u ip m e n t.

o v e r l o o k e d b y d e n tis ts a n d s c i e n ti s t s

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is th a t o f c r e e p r e s i s t a n c e . 2 In th is a r e a

JO H N w . M C L E A N , M D S, L D S . R C S

c id e d t h a t d e n tis tr y is a f in e p r o f e s s io n

th e E B A c e m e n t s a r e n o t v e r y g o o d . I

L O N D O N , EN G

a n d s u b s titu te c o u r s e s in d i s s e c tio n f o r

s u g g e s t th a t D r . S h illin g ’ s f a ilu r e s o c ­

co u rses

c u r r e d b e c a u s e th e c e m e n t “ m o v e d ”

in d e n ta l e c o n o m i c s

to w a r d b e n e f i ts f o r th e

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under

s tre ss .

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d e n tis t? G E R A R D S. F R A N K E L , D D S B E V E R L Y H IL L S , C A L IF

w e n e e d in o u r c e m e n t s is high c r e e p r e s i s t a n c e a n d rig id ity , t o g e t h e r w ith a d e q u a t e s tr e n g t h p r o p e r t i e s , r e s i s t ­ a n c e to s o lu b ility , a n d b io lo g ic a l c o m ­ p a tib ility .

C em ent failure in bridges

In

a d d iti o n ,

a d h e s io n

to

to o th s t r u c t u r e is e s s e n t i a l . T h e p o ly c a rb o x y la te

c e m e n ts

fulfill

m ost of

■ T h e l e t t e r f r o m D r . G e o r g e S h illin g

th e s e r e q u i r e m e n t s e x c e p t f o r c r e e p

(The Journal, A u g u s t ) is e x t r e m e l y in ­

re sista n c e , and h ere

t e r e s tin g . A t th e p r e s e n t t i m e , th e r e

p h a te

a r e fe w a r e a s in r e s t o r a t i v e d e n tis tr y

s e q u e n tl y , in c a s e s w h e r e r e te n t io n o f

w h e r e m o r e c o n t r o v e r s y e x i s t s th a n in

th e c a s t i n g s is m a r g i n a l, th e z in c p h o s ­

th e field o f c e m e n t a t i o n . D r . S h illin g

p h a te c e m e n t s a r e b e t t e r . 3

has

had

v ery

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w ith a lu m in a E B A

r e s u lts

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Toward total health care ■

T h e c r i t i c i s m le v e le d a t th e p o l y c a r b o x y la te

1. Wilson, A .D ., and Bachelor, R .F . Zinc oxide-eugenol cements. 2. Study o f erosion and disintegration. J Dent Res 49:593, 1970. 2. Wilson, A .D ., and others. Experimental luting which is based on the glass-ionomer ce­ ments. Br Dent J 142:117-122, 1977. 3. M cLean, J.W . Polycarboxylate cements: 5 years’ experience in general practice. Br Dent J 132:9-15, 1972. 4. Hotz, P ., and others. T he bonding o f glassionomer cements to metal and tooth substrates. Br Dent J 142:41-47, 1977.

o n ly

In c o o p e r a t i o n w ith F a i r le i g h D i c k ­

in s o n

U n iv e rsity

d e n ta l

sch o o l

and

th e B e r g e n C o u n t y D e n ta l S o c i e t y , 11 JADA, Vol. 96, January 1978 ■ 25

Cement failure in bridges.

LETTERS TO THE JOURNAL THE JOURNAL devotes th is section to com m ent by readers on top ics of current interest to dentistry. The m anaging ed itor r...
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