5 Antibiotics and Dental Caries BASIL G. BIBBY
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Eastman Dental Center, Rochester, Ν. Y . 14603
When
fed in water or diet, penicillin
biotics
consistently
applications Clinical
on animals'
teeth
studies in human
frices or as prophylaxis
in animals.
seem to have
against
rheumatic
to the manner
of use rather than the absence
long-range ecological
an important
ill effects may balance
findings
result
of the oral
are probably of
consideration
from
effect.
in denti
fever gave
While
properties,
negative
anti Topical
some
subjects using antibiotics
sistent results. cariostatic
The
and some other
limit caries activity
disturbance
incon related inherent is of
that the
flora.
i n i t i a l studies o n t h e relationships b e t w e e n a n t i b i o t i c s a n d d e n t a l caries w e r e d e s i g n e d to i n d i c a t e t h e i m p o r t a n c e of b a c t e r i a o r c e r t a i n
b a c t e r i a l g r o u p s i n its e t i o l o g y . T h e r e a f t e r , attempts w e r e m a d e t o estab l i s h t h e usefulness
of c e r t a i n a n t i b i o t i c s i n caries p r e v e n t i o n i n m a n .
R e c e n t l y they h a v e b e e n u s e d a g a i n i n caries research f o r e v a l u a t i n g t h e i m p o r t a n c e of specific b a c t e r i a l types a n d testing n e w ideas i n caries etiology. T w e n t y years ago, t h e b e l i e f that g r a m p o s i t i v e b a c t e r i a , s u c h as t h e streptococci,
w e r e t h e a c t i v a t i n g agents of d e n t a l d e c a y w a s n o t as
g e n e r a l l y a c c e p t e d as i t is t o d a y , a n d some d e n t a l investigators b e l i e v e d that i n a d e q u a t e n u t r i t i o n m i g h t h a v e e q u a l i m p o r t a n c e .
O n e w a y of
settling this q u e s t i o n w a s t o a d d a n agent, s u c h as p e n i c i l l i n , w h i c h w o u l d d e s t r o y a c i d - p r o d u c i n g g r a m p o s i t i v e organisms, to a d i e t w h i c h w a s k n o w n to cause d e n t a l d e c a y i n rats, a n d see w h e t h e r i t w o u l d p r o t e c t the a n i m a l s against caries.
I n s u c h a n experiment, i t w a s f o u n d
(29)
that rats e a t i n g a c a r i e s - p r o d u c i n g d i e t w i t h 75 u n i t s of p e n i c i l l i n p e r g r a m of f o o d o r w a t e r d e v e l o p e d n o d e n t a l d e c a y , w h e r e a s a n i m a l s e a t i n g t h e p e n i c i l l i n - f r e e c o n t r o l d i e t d e v e l o p e d caries as u s u a l . T h e l a c t o b a c i l l i , w h i c h at that t i m e w e r e b e l i e v e d to b e causative agents of caries, h a d b e e n e l i m i n a t e d f r o m t h e m o u t h s of t h e p e n i c i l l i n g r o u p . F o l l o w i n g this a p p r o a c h , S t e p h a n et al. (36, 37)
tested t h e effect of p e n i c i l l i n , A u r e o 46
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
5.
Antibiotics
BiBBY
and
Dental Caries
47
mycin, bacitracin, Chloromycetin, streptomycin, Terramycin,
cephalo
s p o r i n , a n d p o l y m y x i n o n rat caries for the d o u b l e p u r p o s e of d e t e r m i n i n g the r e l a t i v e effectiveness of these agents i n p r e v e n t i n g caries a n d i n d i c a t i n g w h i c h spectra of m i c r o o r g a n i s m s p l a y e d the most i m p o r t a n t p a r t i n its etiology. T h e i r findings s h o w e d that o n l y c e p h a l o s p o r i n a n d p o l y m y x i n f a i l e d to r e d u c e caries, a n d that n o n e of the b r o a d - s p e c t r u m a n t i b i o t i c s w a s a n y m o r e effective t h a n p e n i c i l l i n i n this respect. T h e f a i l u r e of c e p h a l o s p o r i n , w h i c h is effective against most g r a m p o s i t i v e organisms
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except some s t r e p t o c o c c i a n d l a c t o b a c i l l i , t o r e t a r d caries i n d i c a t e d the i m p o r t a n c e of these b a c t e r i a l types i n caries.
T h e n e g a t i v e results w i t h
p o l y m y x i n l i k e w i s e s h o w e d that g r a m n e g a t i v e organisms h a d n o signifi c a n c e i n the c a u s a t i o n of rat caries. Fitzgerald and Jordan
(5)
tested 10 units or 10 μξ
p e r g r a m of
several different a n t i b i o t i c s i n c a r i o g e n i c diets i n a rat s t u d y .
A l l the
agents s i g n i f i c a n t l y r e d u c e d the caries score b e l o w that g i v e n b y control diet.
the
P e n i c i l l i n w a s m o s t effective, w i t h o n l y one t h i r d of t h e
a n i m a l s s h o w i n g caries, f o l l o w e d i n o r d e r b y o r y t h r o m y c i n , z i n c b a c i tracin, carbomycin, and neomycin. I n a s t u d y of the m e c h a n i s m s of caries p r e v e n t i o n b y v a r i o u s agents, M c C l u r e et al
(28)
f o u n d that p e n i c i l l i n at 10 u n i t s p e r g r a m of d i e t w a s
m o r e effective i n p r e v e n t i n g caries i n w h i t e rats t h a n 50 p p m of s o d i u m fluoride
o r i o d o a c e t i c a c i d or a h i g h - m i n e r a l diet. T h e y i n t e r p r e t e d this
to m e a n that b a c t e r i a l a c t i v i t y o n the teeth w a s of p r i m a r y i m p o r t a n c e i n c a u s i n g caries. I n e n d e a v o r i n g to d e t e r m i n e w h i c h types of b a c t e r i a p r o d u c e d caries i n t h e i r caries-susceptible
s t r a i n of rats, R o s e n et al
(33)
f o u n d that
w h e n 500 units o f p e n i c i l l i n or 0 . 0 2 5 % T e r r a m y c i n p e r g r a m of d i e t w e r e f e d , n o caries o c c u r r e d i n the p e n i c i l l i n rats, b u t a l l t h e i r T e r r a m y c i n rats s h o w e d caries.
S i n c e b o t h a n t i b i o t i c s are effective
against
g r a m p o s i t i v e organisms, they c o n c l u d e d that some u n r e c o g n i z e d types of b a c t e r i a m u s t b e r e s p o n s i b l e f o r caries i n t h e i r a n i m a l s . S h a w a n d S w e e n e y (34)
u s e d c o t t o n rats, w h i t e rats, a n d d e s a l i v a t e d
w h i t e rats i n a c o m p a r i s o n of the effectiveness of different levels of a v a r i e t y o f a n t i b i o t i c agents o n caries, a n d also c o m p a r e d t h e i r in effectiveness against a h u m a n a n d rat strain of Lactobacillus
P e n i c i l l i n w a s the m o s t effective i n r e d u c i n g caries i n b o t h species. mycin, Chloromycetin, streptomycin, and Terramycin were
vitro
acidophilus. Aureo-
moderately
effective, whereas p a n t h e n o l , t y r o t h r i c i n , s u b t i l i n , a n d b a c i t r a c i n
gave
o n l y s l i g h t or n o p r o t e c t i o n . N o c o r r e l a t i o n w a s f o u n d b e t w e e n effective ness i n r e d u c i n g a n i m a l caries a n d the a b i l i t y to p r e v e n t a c i d f o r m a t i o n i n the l a c t o b a c i l l u s cultures.
F a l l a a n d S h a w (4)
s h o w e d that
injected
p e n i c i l l i n w o u l d r e d u c e caries i n rats, b u t to b e effective, levels t w i c e as h i g h as i n the f o o d h a d to b e u s e d .
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
48
DIETARY
C H E M I C A L S
VS.
D E N T A L
U s i n g a 15-day, rather t h a n the u s u a l 80- to 100-day, p e r i o d , M u h l e m a n n et al. (31) a d d i t i o n s of 0.01 to 0 . 2 %
CARTES
experimental
m a d e a n extensive c o m p a r i s o n of d i e t a r y
of a n t i b a c t e r i a l a n d a n t i f u n g a l a n t i b i o t i c s a n d
other a n t i b a c t e r i a l c h e m i c a l a n d cariostatic agents o n the i n i t i a t i o n of rat caries.
T h e a n t i b a c t e r i a l agents u s e d w e r e p e n i c i l l i n , A u r e o m y c i n ,
D e c l o m y c i n , erythromycin, O l e a n d o m y c i n , novobiocin, thiostrepton, bacitracin,
dihydrostreptomycin, and
chloramphenicol.
The
antimycotic
agents u s e d w e r e n y s t a t i n , g r i s e o f u l v i n , a m p h o t e r i c i n B , e c h i n o m y c i n ,
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usnic acid, and penicillin,
flavofungin.
T h e antibiotics w i t h gram positive s p e c t r a —
Oleandomycin, erythromycin, and
novobiocin—were
most
effective i n p r e v e n t i n g e a r l y caries, a n d t h e i r b r i e f l y - p r e s e n t e d
results
c a n b e i n t e r p r e t e d as s h o w i n g caries r e d u c t i o n s of f r o m 85 to 9 0 %
below
t h e w a t e r controls.
Tetracyclines—Aureomycin, Tetracyn, and Declo-
m y c i n — g e n e r a l l y gave r e d u c t i o n s i n the 6 0 % w e r e c o m p a r a b l e i n effectiveness t o s o d i u m
range a n d i n this respect fluoride,
as w e r e the a n t i -
b i o t i c s w i t h b o t h g r a m p o s i t i v e a n d g r a m negative spectra. a n t i m y c o t i c s n o r the disinfectants r e d u c e d caries.
N e i t h e r the
F r o m these results, it
w a s c o n c l u d e d that the a n t i b i o t i c s w e r e the most effective agents against rat caries. T h e o b v i o u s c o n c l u s i o n f r o m a l l of these studies is that a n t i b i o t i c s are c a p a b l e of p r e v e n t i n g d e n t a l d e c a y i n a n i m a l s . S e v e r a l o f t h e m are v e r y potent, a n d t h e i r effectiveness seems to b e r e l a t e d to t h e
capacity
to interfere w i t h the g r o w t h of g r a m p o s i t i v e b a c t e r i a i n g e n e r a l , rather t h a n the l a c t o b a c i l l i i n p a r t i c u l a r . T h e d e m o n s t r a t e d effectiveness of antibiotics i n p r e v e n t i n g a n i m a l caries l e d to a c o n s i d e r a t i o n of their use to c o m b a t d e n t a l d e c a y i n m a n . A s a result, b o t h in vitro a n d a n i m a l caries studies w e r e u n d e r t a k e n , w i t h a v i e w to d e v e l o p i n g p r o p h y l a c t i c p r o d u c t s for h u m a n use. T h e in vitro experiments w e r e b a s e d o n the k n o w l e d g e that d e n t a l caries results f r o m d e c a l c i f i c a t i o n of teeth b y acids f o r m e d b y b a c t e r i a l f e r m e n t a t i o n of c a r b o h y d r a t e s , a n d , therefore, a n y agent w h i c h w o u l d effectively interfere w i t h the p r o d u c t i o n of a c i d w o u l d b e l i k e l y to p r e vent tooth decay.
U s i n g this a p p r o a c h , large n u m b e r s of
antibacterial
agents a n d e n z y m e i n h i b i t o r s h a v e b e e n tested i n several w a y s to i n d i c a t e t h e i r p o t e n t i a l usefulness i n p r e v e n t i n g caries.
Zander and B i b b y
(44)
m e a s u r e d r e d u c t i o n of a c i d f o r m a t i o n f r o m glucose i n s a l i v a , F o s d i c k
(9)
c a l c i u m loss f r o m e n a m e l i n a s a l i v a r y f e r m e n t a t i o n system, a n d M a h l e r a n d M a n l y (27) p a c k e d organisms
acid formation i n an "artificial plaque" composed obtained b y centrifuging m o u t h washings.
In
of our
experiments, a n d F o s d i c k ' s , p e n i c i l l i n w a s the most effective of the m a n y agents tested.
F o s d i c k c o n c l u d e d that since p e n i c i l l i n w a s a b s o r b e d i n
p r o t e i n films, a n d other e n z y m e i n h i b i t o r s w e r e not, i t w o u l d h a v e
a
l a s t i n g effect o n the c a r i e s - p r o d u c i n g a c t i v i t y of the b a c t e r i a l p l a q u e s o n
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
5.
Antibiotics
BIBBY
the t o o t h surface.
and
Dental
49
Caries
H o w e v e r , i n M a h l e r a n d M a n l y ' s (27)
experiments,
i n w h i c h p a c k e d m i c r o o r g a n i s m s w e r e u s e d rather t h a n
suspensions,
p e n i c i l l i n w a s ineffective i n c h a n g i n g the course of a c i d p r o d u c t i o n . T h i s finding
o n short-term a c i d f o r m a t i o n i n " a r t i f i c i a l p l a q u e " w a s e x t e n d e d
i n t o the m o u t h b y B r u d e v o l d a n d H a w e s ' (3)
finding
that p e n i c i l l i n d i d
not interfere w i t h a c i d f o r m a t i o n i n p l a q u e s o n h u m a n t o o t h surfaces. A different sort of in vitro e v i d e n c e o n the effectiveness of p e n i c i l l i n i n p r e v e n t i n g caries w a s offered b y Z a n d e r a n d B i b b y (44),
w h o showed
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t h a t s a l i v a c o l l e c t e d f r o m h u m a n m o u t h s 2 h o u r s after a p e n i c i l l i n rinse s t i l l l a c k e d the a b i l i t y to f e r m e n t glucose. W h i l e a t t e n t i o n has b e e n c e n t e r e d o n p e n i c i l l i n , other g i v e c o m p a r a b l e i n h i b i t i o n of a c i d f o r m a t i o n i n in vitro Brudevold and B i b b y (2)
antibiotics
tests (2,
29).
f o u n d that a m o n g e x p e r i m e n t a l l y d e v e l o p e d
a n t i b i o t i c s that the m a n u f a c t u r e r s d e e m e d u n s u i t a b l e f o r systemic a d m i n i s t r a t i o n there w e r e some w h i c h w e r e e q u a l l y as effective as p e n i c i l l i n i n reducing acid production b y m o u t h bacteria.
F r o m this, i t m a y b e s u g -
gested that the l o n g - r a n g e p o s s i b i l i t i e s of u t i l i z i n g a n t i b i o t i c s i n caries c o n t r o l m i g h t w e l l d e p e n d u p o n the selection o f types w h i c h w o u l d n o t b e e m p l o y e d f o r a n y other m e d i c a l p u r p o s e . S e v e r a l a n i m a l - f e e d i n g studies d e s i g n e d to s u p p l e m e n t those a l r e a d y c i t e d h a v e b e e n c a r r i e d out to select a n d evaluate a n t i b i o t i c s f o r i n c l u s i o n i n d e n t i f r i c e s i n t e n d e d f o r caries p r e v e n t i o n i n m a n . finding
L o o k i n g towards
the lowest effective c o n c e n t r a t i o n of p e n i c i l l i n w h i c h w o u l d b e
effective against caries, W e b m a n et al.
(40)
s h o w e d that as l i t t l e as 2
units of p e n i c i l l i n a d d e d to a c a r i e s - p r o d u c i n g d i e t r e d u c e d d e n t a l d e c a y i n rats b y almost a t h i r d , a n d that a r e d u c t i o n of l a c t o b a c i l l u s c o u n t a n d a n increase
of g r a m negative organisms also o c c u r r e d i n the
m o u t h s . V o l k e r et al. (38)
animals'
c o m p a r e d the effect of p e n i c i l l i n , a m e r c u r i c
benzoate, a n d a sarcosinate, a l l of w h i c h i n h i b i t e d a c i d p r o d u c t i o n b y s a l i v a r y b a c t e r i a a n d w e r e r e t a i n e d o n the t o o t h surface, o n
hamster
caries. T h e y f o u n d p e n i c i l l i n to b e the most effective u n d e r the t w o test c o n d i t i o n s u s e d . I n another c o m p a r i s o n of the effectiveness of p e n i c i l l i n a n d other cariostatic agents, P i n d b o r g (32)
f o u n d that 20 m g of p r o c a i n e
p e n i c i l l i n p e r k g of d i e t ( t h e e q u i v a l e n t of 20 i n t e r n a t i o n a l u n i t s p e r g r a m of d i e t ) r e d u c e d d e n t a l d e c a y b y 8 1 % , whereas 10 p p m of s o d i u m fluoride
or of stannous
fluoride
a d d e d to the same d i e t gave
caries
r e d u c t i o n s of o n l y 31.6 a n d 28.9, respectively. Another type
of
experiment,
i n w h i c h antibiotic mixtures
were
b r u s h e d o n a n i m a l teeth, has b e e n u s e d to p r e d i c t t h e p o t e n t i a l effectiveness of a n t i b i o t i c dentifrices i n m a n . I n the first e x p e r i m e n t of this sort, Z a n d e r a n d B i b b y (44)
b r u s h e d a s o l u t i o n c o n t a i n i n g 500 u n i t s of p e n i -
c i l l i n p e r c c o n t h e t e e t h of hamsters
w h i c h were kept on a
caries-
p r o d u c i n g d i e t f o r 40 days. I n e i g h t animals w h o s e teeth w e r e b r u s h e d
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
50
DIETARY
C H E M I C A L S
VS.
D E N T A L
CARIES
w i t h p e n i c i l l i n , there was less t h a n one c a v i t y p e r a n i m a l , whereas i n the w a t e r - b r u s h e d c o n t r o l g r o u p , the a n i m a l s h a d a n average of seven cavities. I n another hamster e x p e r i m e n t ( 4 5 ) , solutions c o n t a i n i n g v a r i o u s c o n c e n trations of p e n i c i l l i n , A u r e o m y c i n , a n d t y r o t h r i c i n w e r e b r u s h e d o n the teeth.
P e n i c i l l i n w a s most effective.
testing i n c h i l d r e n , Shiere ( 3 5 )
T o select a d e n t i f r i c e f o r c l i n i c a l
b r u s h e d five different t y r o t h r i c i n d e n t i -
frices a n d a c o n t r o l o n hamster teeth.
T h e one w h i c h gave the m a x i m a l
caries
c o n t r o l , was
reduction, 25.6%
b e l o w the
subsequently
found
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e q u a l l y effective i n m a n . T h e a c c u m u l a t e d e v i d e n c e that p e n i c i l l i n w o u l d interfere w i t h a c i d formation b y salivary bacteria and w o u l d unquestionably prevent dental caries i n a n i m a l s l e d to tests of its caries-preventive effect i n m a n . B e f o r e m e n t i o n i n g the findings i n the c l i n i c a l tests w h i c h h a v e b e e n c a r r i e d o u t u s i n g a n t i b i o t i c dentifrices, it s h o u l d b e p o i n t e d out
that
m a n y v a r i a b l e s b e y o n d that of the agent u s e d c o m p l i c a t e the o b t a i n i n g of r e l i a b l e results i n h u m a n studies.
F o r instance, a n agent w h i c h is
effective i n a n i m a l s m a y not b e of a n y use i n m a n , or one e x a m i n a t i o n a n d r e c o r d i n g p r o c e d u r e m a y f a i l to s h o w differences w h i c h w o u l d a p p e a r i f another w e r e u s e d , b u t m o s t i m p o r t a n t l y , the w h o l e result is g o i n g to d e p e n d u p o n the extent to w h i c h the instructions o n the use of the test d e n t i f r i c e are f o l l o w e d . O b v i o u s l y , n o t h e r a p e u t i c agent c a n b e expected to p r o d u c e benefit as l o n g as it r e m a i n s i n its container. S e v e r a l c l i n i c a l tests o n the effect of a n t i b i o t i c dentifrices o n caries have been reported.
T h e first s t u d y , that of H i l l et al.
(15),
used a
p o w d e r c o n t a i n i n g 500 units of p e n i c i l l i n p e r g r a m a n d p r o d u c e d n o a p p a r e n t r e d u c t i o n i n d e n t a l decay, a l t h o u g h a r e d u c t i o n i n s a l i v a r y l a c t o b a c i l l u s c o u n t was o b s e r v e d .
H o w e v e r , since the test subjects w e r e
8- to 16-year-old boys w h o s e u n s u p e r v i s e d b r u s h i n g habits
are
most
u n p r e d i c t a b l e , the negative result c o u l d h a v e b e e n the result of l i m i t e d use of the d e n t i f r i c e .
I n another
study, Zander
(43)
found a
55%
r e d u c t i o n i n d e n t a l d e c a y i n 6- to 14-year-old c h i l d r e n i n the first year, a n d a 57.6%
r e d u c t i o n i n the s e c o n d y e a r w h e n a p o w d e r c o n t a i n i n g
500 units of p e n i c i l l i n p e r g r a m w a s b r u s h e d o n the teeth u n d e r superv i s i o n five times p e r w e e k i n school. I n the t h i r d test of a n a n t i b i o t i c d e n t i f r i c e ( 1 6 ) , 1000 units of p e n i c i l l i n p e r g r a m i n a n a n h y d r o u s c r e a m y base was used under supervised brushing.
It w a s o n l y s l i g h t l y effective i n
r e d u c i n g d e n t a l d e c a y a n d d i d not r e d u c e the l a c t o b a c i l l u s c o u n t i n the s a l i v a . T h e l a c k of success i n this instance c o u l d h a v e b e e n c a u s e d b y the p e n i c i l l i n not b e i n g l i b e r a t e d f r o m the d e n t i f r i c e r a p i d l y e n o u g h i n the m o u t h . I n a s m a l l test ( 3 9 )
w i t h a p o w d e r c o n t a i n i n g 100 units of
p e n i c i l l i n p e r g r a m , o r p h a n a g e c h i l d r e n s h o w e d n o s l o w i n g of the caries attack o r r e d u c t i o n of the
l a c t o b a c i l l u s c o u n t as c o m p a r e d w i t h
the
controls. I n the o n l y d e n t i f r i c e s t u d y w i t h a n a n t i b i o t i c other t h a n p e n i -
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
5.
BIBBY
Antibiotics
and
Dental
51
Caries
c i l l i n ( 3 5 ) , a t y r o t h r i c i n d e n t i f r i c e w h i c h h a d b e e n s h o w n to b e effective against hamster caries gave a 2 6 %
reduction i n dental decay w h e n com-
p a r e d w i t h a c o n t r o l paste. Using
only lactobacillus
counts
and acid formation by
m o u t h organisms to assess caries a c t i v i t y , L u d w i c k et al
(26)
aciduric compared
different concentrations of several a n t i b i o t i c s a n d other agents over 6- to 7-week p e r i o d s . T h e y f o u n d that a p o w d e r c o n t a i n i n g 0.07%
penicillin
was m o r e effective t h a n p o w d e r s c o n t a i n i n g t y r o t h r i c i n , s t r e p t o m y c i n ,
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g r a m i c i d i n , b a c i t r a c i n , a n d other anticaries agents. T h e effect of a n a n t i b i o t i c i n a m o u t h w a s h o n caries seems to h a v e b e e n tested o n l y o n c e ( 2 3 ) , i n w h i c h a 1-year t r i a l of b a c i t r a c i n i n a m o u t h w a s h f a i l e d to r e d u c e caries.
W h i l e p e n i c i l l i n has b e e n i n c o r p o r a t e d i n t o c h e w i n g g u m a n d
troches f o r other o r a l uses, t h e r e does not seem to h a v e b e e n a n y o r g a n i z e d s t u d y of t h e i r effect o n d e n t a l caries. R e a s o n f o r b e l i e v i n g that p e n i c i l l i n is c a p a b l e of r e d u c i n g d e n t a l d e c a y i n h u m a n subjects has c o m e f r o m another t y p e of use.
Many
c h i l d r e n are p l a c e d o n p r o p h y l a c t i c p e n i c i l l i n f o r the c o n t r o l of r h e u m a t i c fever or as a means of c o m b a t t i n g c h r o n i c p u l m o n a r y
diseases.
S e v e r a l c o m p a r i s o n s h a v e b e e n m a d e of patients u n d e r s u c h t h e r a p y .
In
one of these ( 2 5 ) , r h e u m a t i c f e v e r patients w h o h a d b e e n o n p r o p h y l a c t i c p e n i c i l l i n f r o m the age of 7 years h a d a p p r o x i m a t e l y 4 0 %
f e w e r carious
teeth t h a n c h i l d r e n of c o m p a r a b l e age w i t h o u t a n t i b i o t i c experience.
In
a later s t u d y ( 1 3 ) , 75 a n d 74 c h i l d r e n w h o r e c e i v e d d a i l y o r a l p e n i c i l l i n , r e s p e c t i v e l y , 200,000 u n i t s f o r the p r e v e n t i o n of r e c u r r e n t fever
and
1-3,000,000 units w i t h
occasional
tetracycline
rheumatic for
chronic
r e s p i r a t o r y diseases, s h o w e d o n l y one t h i r d of the caries i n c r e m e n t
of
c o n t r o l subjects. T h e in vitro
a n d a n i m a l studies, together w i t h p r e l i m i n a r y c l i n i c a l
e v i d e n c e of caries r e d u c t i o n i n m a n , r e s u l t e d i n the b r i e f a p p e a r a n c e o n the m a r k e t of t w o p e n i c i l l i n dentifrices. their disappearance.
S e v e r a l reasons c o n t r i b u t e d to
O n e o f these w a s that c o m p e t i n g t h e r a p e u t i c d e n t i -
frices w i t h greater cosmetic a p p e a l w e r e offered at a b o u t the same t i m e . A n o t h e r is that t h e y w e r e treated w i t h s u s p i c i o n b y b o t h the m e d i c a l a n d d e n t a l professions, w h i c h , as experience g r e w , a t t a c h e d i n c r e a s i n g w e i g h t to the dangers of d e v e l o p i n g p e n i c i l l i n - r e s i s t a n t organisms a n d a l l e r g i c states. T h e e v i d e n c e o n this latter subject rests i n some
demonstrations
that the m o u t h s of c h i l d r e n u s i n g p e n i c i l l i n dentifrices c o n t a i n e d i n creased p o p u l a t i o n s of g r a m n e g a t i v e organisms i n t w o studies (14,
42).
C h i l d r e n u s i n g Z a n d e r s 500-unit p e n i c i l l i n p o w d e r f o r 1£ years d i d not s h o w a n increase i n p e n i c i l l i n - r e s i s t a n t l a c t o b a c i l l i (8) a n d s t a p h y l o c o c c i (22),
or
streptococci
b u t after 3 years m o r e p e n i c i l l i n - r e s i s t a n t strep-
t o c o c c i , m i c r o c o c c i , a n d neisseria w e r e f o u n d (21,
41).
I n patients o n
200,000-3,000,000 units of o r a l p e n i c i l l i n p e r d a y , a s l i g h t increase
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
in
52
DIETARY
C H E M I C A L S
VS.
D E N T A L
CARIES
a n t i b i o t i c resistance w a s n o t e d w i t h o u t a n y significant change i n b a c t e r i a l e c o l o g y of the m o u t h ( I I ) .
H o w e v e r , f a i l u r e to establish the safety of
p e n i c i l l i n i n the f a c e of i n d i c a t i o n s of increases i n the n u m b e r of p e n i cillin-resistant b a c t e r i a l types r e s u l t e d i n u n f a v o r a b l e o p i n i o n f r o m a n A d H o c C o m m i t t e e of the F e d e r a l F o o d a n d D r u g A d m i n i s t r a t i o n
(24),
a n d l i k e w i s e , the C o u n c i l o n D e n t a l T h e r a p e u t i c s of t h e A m e r i c a n D e n t a l A s s o c i a t i o n offered a c r i t i c a l o p i n i o n ( 1 7 ) , r e c o m m e n d i n g that " p e n i c i l l i n dentifrices
s h o u l d not
be
d i s t r i b u t e d . . . except
on
a
prescription
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basis." I n a n y case, w h e t h e r i t w a s f o r this or other reasons, the p e n i c i l l i n d e n t i f r i c e s d i d not c o n t i n u e o n the m a r k e t . A p a r t f r o m c o m m e r c i a l c o n siderations, this m a y h a v e b e e n a p r e m a t u r e d e v e l o p m e n t b e c a u s e e v e n i f p e n i c i l l i n c o u l d not b e u s e d i n e v e r y d a y d e n t i f r i c e s , a p e n i c i l l i n d e n t i f r i c e m i g h t h a v e h a d some usefulness i n s h o r t - t e r m treatment of patients w i t h o t h e r w i s e u n c o n t r o l l a b l e d e n t a l d e c a y . It is also possible that u s i n g a n t i b i o t i c s i n other w a y s m i g h t b e justified i n p h y s i c a l l y h a n d i c a p p e d or m e n t a l l y deficient patients, w h e r e o r d i n a r y m e t h o d s of caries c o n t r o l cannot be used. T h e last phase of e x p e r i m e n t a t i o n w i t h a n t i b i o t i c s has b e e n d i r e c t e d m a i n l y t o w a r d s i n v e s t i g a t i n g the r o l e of i n f e c t i o n w i t h specific m i c r o organisms i n e x p e r i m e n t a l caries. F o l l o w i n g the finding t h a t t r a n s m i s s i o n of m i c r o o r g a n i s m s w a s i m p o r t a n t i n i n i t i a t i n g a c t i v e caries i n a n i m a l s , i t b e c a m e i m p o r t a n t to establish the s p e c i f i c i t y of the b a c t e r i a l types i n volved.
A f t e r i t w a s f o u n d that the caries seemed to result f r o m o r a l
c o n t a m i n a t i o n w i t h the streptococcus
f r o m the feces, K e y e s (18)
was
a b l e to demonstrate that p e n i c i l l i n a n d e r y t h r o m y c i n w h i c h e l i m i n a t e d s u c h s t r e p t o c o c c a l types f r o m the m o u t h also p r e v e n t e d caries. T o d e m onstrate the s p e c i f i c i t y of specific strains of organisms, test s t r e p t o c o c c i w e r e m a d e streptomycin-resistant so that they c o u l d b e u s e d as m a r k e r s a n d i d e n t i f i e d i n the presence
of other s t r e p t o c o c c a l types
(8).
This
m a d e i t possible to s h o w that the m a r k e d types w e r e t r a n s m i t t e d f r o m one a n i m a l to another (6)
a n d to i d e n t i f y t h e m as t h e i n f e c t i v e agents
w h i c h p r o d u c e caries i n o t h e r w i s e caries-free a n i m a l s . This technique
of d e v e l o p i n g s t r e p t o m y c i n resistance
strains of s t r e p t o c o c c i w a s u s e d b y K r a s s e et al. (20)
i n specific
to s t u d y " i n f e c t i o n "
of h u m a n m o u t h s w i t h exogenous c a r i o g e n i c streptococci.
H e demon-
strated l o n g - t e r m s u r v i v a l of a h u m a n c a r i o g e n i c streptococcus i m p l a n t a t i o n i n m o u t h s i n w h i c h it w a s p r e v i o u s l y absent.
after
Cariogenic
h a m s t e r s t r e p t o c o c c i s u r v i v e d for shorter p e r i o d s . A n o t h e r w a y i n w h i c h the a n t i b i o t i c s h a v e b e e n u s e d t o i n d i c a t e the c a r i o g e n i c i t y of specific b a c t e r i a l types is b y u s i n g t h e m as G u g g e n h e i m et al.
(10)
h a v e d o n e to depress t h e u s u a l o r a l flora to p r o d u c e a
p a r t i a l gnotobiosis so that t h e i n t r o d u c e d test t y p e w i l l f a c e a less c o m p e t i t i v e struggle f o r existence a n d b e c o m e established i n a s i t u a t i o n i n
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
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5.
BIBBY
Antibiotics and Dental Caries
53
which it would not otherwise survive. Using a similar approach, Bowen (I) was able to show that an erythromycin-resistant streptococcus from human teeth could be established i n the mouths of monkeys rendered partially gnotobiotic by administration of erythromycin. A further use for antibiotics i n caries research has been to indicate the importance of bacterial polysaccharides i n the sticky masses or plaques which form on the tooth surfaces of rats and hamsters on a sucrose diet (19). Since tooth destruction occurs under these plaques, agents which w i l l inhibit the streptococci responsible for their formation would have potential importance i n the prevention of caries i n man. Keyes (19) has shown that i n rats and hamsters daily short applications of penicillin, erythromycin, streptomycin, tetracycline, and speramycin are very effective i n preventing plaque formation and subjacent tooth decalcification. Vancomycin was somewhat less so, and neomycin, bacitracin, and thiostrepton without effect. W h i l e caution cannot be too strongly emphasized i n projecting animal findings to conditions i n man, Mitchell and Holmes (30) have demonstrated that frequent applications of vancomycin w i l l prevent the development of one type of plaque deposit in human mouths. In conclusion, a final question has to be faced—that is, whether repeated use i n the mouth of a therapeutic vehicle containing a "safe" antibiotic free of a l l medical hazards would be wise. If it killed a wide spectrum of oral bacterial types, its use would not be without danger because elimination of the predominant bacterial types i n the mouth might allow other organisms, such as fungi, to become established, with possible unfortunate pathological effects. The perfect anticaries antibiotic w i l l need to have preferential antagonism for only those types which are particularly important i n caries causation and no effect on other types. Achieving this goal should not be beyond the possibilities of future research.
Literature Cited (1) (2) (3) (4) (5) (6) (7) (8)
Bowen, W., personal communication, 1968. Brudevold, F., Bibby, B. G., unpublished findings. Brudevold, F., Hawes, R. R.,J.Dental Res. 1952, 31, 474. Falla, W . S., Shaw, J. H . , Arch. Oral Biol. 1965, 10, 537. Fitzgerald, R. J., Jordan, H . J., J. Dental Res. 1955, 34, 685. Fitzgerald, R. J., Keyes, P. H . , Am. J. Pathol. 1963, 42, 7. Fitzgerald, R. J., Keyes, P. H . , J. Am. Dental Assoc. 1960, 61, 9. Fitzgerald, R. J., Zander, H . A., Jordan, H. J., J. Am. Dental Assoc. 1950, 41, 62. (9) Fosdick, L . S., Ludwick, W . E., J. Dental Res. 1950, 29, 664. (10) Guggenheim, B., Konig, K . G., Muhlemann, H. R., Helv. Odont. Acta 1965, 9, 121. (11) Handelman, S. L . , Hawes, R. R., Arch. Oral Biol. 1965, 10, 353.
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.
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54
DIETARY C H E M I C A L S VS. D E N T A L CARIES
(12) Handelman, S. L., Hawes, R. R.,J.Oral Therap. Pharmacol. 1964, 1, 23. (13) Handelman, S. L., Mills, J. R., Hawes, R. R., J. Oral Therap. Pharmacol. 1966, 2, 338. (14) Hawes, R. R., Thesis, University of Rochester, Rochester, Ν. Y., 1951. (15) Hill, T. J., Kniesner, A. H . , J. Dental Res. 1948, 27, 267. (16) Hill, T. J., Sims, J., Newman,M.,J.Dental Res. 1953, 32, 448. (17) J. Am. Dental Assoc. 1952, 45, 466. (18) Keyes, P. H . , Arch. Oral Biol. 1960, 1, 304. (19) Keyes, P. H., J. Oral Therap. Pharmacol. 1966, 3, 157. (20) Krasse, B., Edwardsson, S., Svensson, I., Trell, L . , Arch. Oral Biol. 1967, 12, 231. (21) Lind, H . E., Antibiot. Chemotherapy 1954, 4, 161. (22) Lind, H . E., Zander, Η. Α., J. Dental Res. 1950, 29, 667. (23) Law, F . E . , Wallace, D . R., Spitz, G. S., Public Health Rept. 1961, 76, 1094. (24) Lewis, Charles N., M.D., personal communication, 1952. (25) Littleton, N . W., White, C. L., J. Am. Dental Assoc. 1964, 68, 520. (26) Ludwick, W . E . , Fosdick, L. S., Schantz, C. W., J. Am. Dental Assoc. 1951, 43, 285. (27) Mahler, I. R., Manly, R. S.,J.Am. Dental Assoc. 1958, 56, 854. (28) McClure, F . J., Falk, J. E . , Rust, J. D., J. Am. Dental Assoc. 1956, 53, 1. (29) McClure, F. J., Hewitt, W . L., J. Dental Res. 1946, 25, 441. (30) Mitchell, D . F., Holmes, L. Α.,J.Periodont. 1965, 36, 202. (31) Muhlemann, H. R., Meyer, R. W., Konig, K. G., Marthaler, T. M., Helv. Odont. Acta 1961, 5, 18. (32) Pindborg, J. J., Acta Odont. Scand. 1958, 16, 383. (33) Rosen, S., Ragheb, C. Α., Hoppert, C. Α., Hunt, H . R., J. Dental Res. 1956, 35, 399. (34) Shaw, J. H., Sweeney, Ε. Α., J. Dental Res. 1957, 36, 349. (35) Shiere, F. R., J. Dental Res. 1957, 36, 237. (36) Stephan, R. M., Fitzgerald, R. J., McClure, F . J., Harris, M . R., Jordan, H . J., J. Dental Res. 1952, 31, 421. (37) Stephan, R. M., Harris, M . R., Fitzgerald, R. J., J. Dental Res. 1952, 31, 475. (38) Volker, J. F., Apperson, L. D., King, W . J., J. Dental Res. 1955, 34, 733. (39) Walsh, J. P., Smart, R. S., New Zealand Dental J. 1951, 47, 118. (40) Webman, H . , Kniesner, A. H., Hill, T. J., J. Dental Res. 1948, 27, 258. (41) Welsh, H . , Randall, W . Α., Buckman, L . E . , Hendrix, F. D . , Antibiot. Chemotherapy 1952, 2, 249. (42) White, B. J., Kniesner, A . H . , Hill, T. J., J. Dental Res. 1949, 28, 267. (43) Zander, Η. Α., J. Am. Dental Assoc. 1950, 40, 569. (44) Zander, Η. Α., Bibby, B. G., J. Dental Res. 1947, 26, 365. (45) Zander, Η. Α., Lisanti, V . F., Shiere, F . R., J. Dental Res. 1951, 30, 139. RECEIVED October 27, 1969.
In Dietary Chemicals vs. Dental Caries; Harris, R.; Advances in Chemistry; American Chemical Society: Washington, DC, 1970.