- Email: [email protected]
A comparison of pH values of in vivo dental plaque after sucrose and sorbitol mouth rinses
FOSDICK AND OTHERS . . . VOLUME 55, AUGUST 1957 • 191
o r ig in a l v e r t ic a l d im e n s io n , o c c lu s a l p la n e
o r ig in a l p la n e
a n d t o o t h p o s it io n in e d e n tu lo u s p a tien ts.
d im e n s io n
T h e t e c h n ic u s e d in v o lv e s d e v e lo p m e n t
t o o t h p o s it io n o n th is p la n e . T h e results
o f a f u n c t io n a l v e r t ic a l d im e n s io n as c lo s e
a re f u n c t io n a l a n d esth etic.
and
of
o c c lu s io n
re s to r a tio n
w ith in of
this
n a tu r a l
3 7 8 0 W ils h ir e B o u le v a r d
to th e o r ig in a l as p o s s ib le , lo c a t io n o f th e
A comparison of p H values of in vivo dental plaque after sucrose and sorbitol mouth rinses
L e o n a r d S . F o s d ic k , * P h .D ., C h i c a g o ; H a r o l d R . E n g la n d e r D .D .S ., M . P . H . ; K i r k C . H o e r m a n ,\ D .D .S ., M .S . , G r e a t L a k e s , III., a n d R o b e r t G . K esel,% D .D .S ., M .S ., C h ic a g o
I t is f e lt b y m a n y in v e s tig a to rs 1' 3 th a t
T h e r e is s tr o n g in v itro e v id e n c e th a t
d e n ta l ca rie s is in itia t e d a n d c o n t in u e d b y
s o r b ito l is n o t r e a d ily fe r m e n t e d b y a c id o -
th e p r o d u c t i o n o f a c i d in th e d e n t o b a c -
g e n ic m o u t h o rg a n is m s . G r u b b 5 d e m o n
te ria l p la q u e d u r in g a s h o r t p e r io d a ft e r
s tra te d th a t s o r b ito l w a s fe r m e n t e d m o r e
th e
in g e s tio n
of
fe r m e n t a b le
ca rb o
s lo w ly
th a n
s u cro se
strain s
of
and
d e x tr o s e
L a c to b a c il lu s
by
h y d ra te s. I f a n o n f e r m e n t a b le s w e e t s u b
v a r io u s
a c id o
s ta n ce c o u l d b e s u b s titu te d f o r s u cro se o r
p h ilu s, o r a l s t r e p t o c o c c i, yea sts, a n d m i x
o t h e r fe r m e n t a b le c a r b o h y d r a t e s , s ig n ifi
tu res o f yeasts a n d L . a c id o p h ilu s in v a
c a n t r e d u c t io n s in th e in c id e n c e o f d e n ta l
riou s m e d ia . I t w a s b e lie v e d th a t s o rb ito l
ca rie s m ig h t b e a tta in e d . S u c h a p o s s i
is o x id iz e d t o s o rb o s e a n d G r u b b d e m o n -
b ility exists w it h th e s u b s titu tio n o f th e h e x a h y d r o x y a lc o h o l, s o r b ito l f o r s u cro se a n d d e x tr o s e in v a r io u s c o n fe c t io n s . S o r b it o l o c c u r s n a t u r a lly in m a n y fru its a n d m a y b e s y n th e tic a lly p r o d u c e d b y th e c a ta ly tic r e d u c t io n o f g lu c o s e . A lt h o u g h s o r b ito l is c o n s id e r e d a n a lc o h o l a n d n o t a
sugar
becau se
it
does
n ot
c o n t a in
a c h a r a c te r is t ic a ld e h y d e o r k e to n e c o n fig u r a t io n , it is a f o o d a n d , as s u ch , c a n b e c o n v e r t e d in to liv e r g ly c o g e n a n d in to g lu c o s e .4 S o r b it o l is u tiliz e d a t a m u c h s lo w e r r a te a ft e r in g e s tio n th a n g lu c o s e ; h o w e v e r , c h ie fly b e c a u s e o f its d e la y e d in te stin a l a b s o r p t io n , its to ta l o x id a t io n app roach es h o u r p e r io d .
th a t o f
g lu c o s e
over
a
24
The o p in io n s o r a ssertion s c o n t a in e d in this a r t ic le a re th e p r iv a t e o n e s o f th e w riter a n d a r e n ot t o b e c o n s tru e d as o ffic ia l o r r e fle c tin g th e v iew s o f th e N avy D e p a rtm e n t o r th e n a va l s e r v ic e a t la r g e . of
* P r o fe s s o r o f ch e m istry , N orth w estern U n iversity S c h o o l D entistry.
fL ie u te n a n t c o m m a n d e r ( D C ) , U n ited S ta tes N avy, d e n ta l re s e a r ch fa c ilit y , d e n ta l d e p a r t m e n t , U. S. N a v al T ra ining C o r p s . of
{P r o fe s s o r o f d en tistry , D entistry.
U n iv ersity
of
Illin ois C o l l e g e
1._ S te p h a n ,_ R. M . In tra -ora l h y d r o g e n - io n c o n c e n tra tio n s a s s o c ia t e d w ith d e n ta l c a r ie s a c t iv it y . J .D . Res. 23:257 A u g . 1944. 2. S tra lfo rs, A . S tu d ies o f m ic r o b io l o g y o f ca rie s . II. A c i d fe r m e n t a t io n in d e n ta l p la q u e s in situ c o m p a r e d with la c t o b a c illu s co u n ts . J .D . Res. 27:576 O c t . 1948. 3. M o o r e , B. W ., a n d o th e rs . F orm a tion o f la c t ic a c id in d e n ta l p la q u e s . I. C a r ie s -a c t iv e in d iv id u a ls . J.D Res. 35:778 O c t . 1956. 4. W ic k , A . N .; A lm e n , M . C ., M e t a b o lis m o f s o r b i t o l. J .A m .P h a r m . 40:542 N o v . 1951.
and J oseph , L. A . (S c ie n t . e d . )
5. G r u b b , T. C . S tu d ie s o n fe r m e n t a t io n o f s o r b it o l b y o r a l m ic r o o r g a n is m s . J .D . Res. 24:3 ! F e b . 1945.
192 • THE JOURNAL OFTHE AMERICAN DENTAL ASSOCIATION
T a b le 1
• D is tr ib u tio n o f 31
c a r ie s a c t iv e
in d iv id u a ls a c c o r d i n g
to
m inimum
pH
v a lu e s
a t t a in e d d u rin g t h e 2 0 m in u te p e r i o d a f t e r a s u c r o s e m ou th rin se
Upper right quadrant
pH
< 5 .3 5.4— 5.6 5.7— 5.9 > 6 .0
Low er left quadrant
Upper left quadrant
N o.
| Per cent
N o.
Per cent
No.
Per cent
No.
Per cent
2 11 7 11
6.5 35.5 22.6 35.5
1 12 8 10
3.2 38.7 25.8 32.3
5 7 12 7
16.1 22.6 38.7 22.6
4 16 6 5
12.9 51.6 19.4 16.1
31
Total
Low er right quadrant
100
31
100
31
100 p e r c e n t o f p H v a lu e s a ft e r s o r b it o l rinses w e re >
100
31
100
6.0 in a ll q u a d ra n ts .
s tra te d th a t b a c t e r ia l e n zy m e s fin d it d iffi
te r m in a tio n s w e r e m a d e , o n e f r o m e a ch
c u lt t o ca u s e th e f u r t h e r d e c o m p o s it io n
p o s t e r io r
o f s o rb o s e .
s id e re d
C r o w le y ,
H arn er,
B en n ett
and
Jay6
q u a d ra n t. any
P la q u e
s u b s ta n ce
w as
n o r m a lly
con fo u n d
a r o u n d th e te e th re g a rd le s s o f its o r ig in .
c o m p a r e d th e in v itr o fe r m e n t a b ilit y o f
T h is
s o r b ito l, g ly c e r o l a n d g lu c o s e b y c e r t a in
d e b ris , b u t n o t f o o d , c a lc u lu s o r d e c a y .
o r a l m ic r o o r g a n is m s ( la c t o b a c illi, s tr e p to
S u ffic ie n t p la q u e t o c o v e r th e h e a d o f a
c o c c i , s t a p h y lo c o c c i a n d y e a s t ) . W it h in
d is c o id in s tr u m e n t w a s r e m o v e d f r o m th e
in c lu d e d
m a t e r ia
a lb a
and
o th e r
2 4 h o u r s , th e v a s t m a jo r it y o f th e c o m
b u c c o p r o x im a l s u rfa ce s o f th e m o la r s a n d ,
m o n o r a l m ic r o o r g a n is m s tested p r o d u c e d
w h e n e v e r p o s s ib le , w a s ta k e n f r o m
s u ffic ie n t a c id f r o m g lu c o s e t o d e c a lc ify
s a m e t o o t h in e a c h p o s t e r io r q u a d r a n t at
th e
e n a m e l; h o w e v e r , th is w a s n o t tr u e o f
e a c h tim e in te r v a l t h r o u g h o u t th e stu d y.
s o r b ito l. A f t e r o n e w e e k th e m e a n p H o f
O v e r 1 00 in d iv id u a ls w e r e s c r e e n e d b u t
s o r b it o l- la c t o b a c illi c u ltu r e s w a s 5 .1 , b u t
o n ly 31 p r o d u c e d a n a c id p o t e n t ia l o f p H
it w a s c o n c l u d e d
th a t s o r b ito l w a s n o t
5 .6 o r b e lo w a t s o m e tim e d u r in g th e 20
lik e ly t o b e r e t a in e d in th e m o u t h f o r so
m in u te in te r v a l a n d th ese w e r e s e le cte d
lo n g a tim e .
f o r s tu d y .
S h o c k le y , R a n d le s a n d D o d d 7 d e m o n
E a c h in d iv id u a l w a s in s t r u c te d t o r e
s tra te d th a t th e m ix e d flo r a o f s a liv a h a d
tu rn a t a p p r o x im a t e ly th e s a m e tim e th e
lit tle t e n d e n c y t o fe r m e n t s o r b ito l d u r in g
f o l l o w i n g d a y . S im ila r p H d e te r m in a tio n s
s h o r t p e r io d s o f in c u b a t io n in v itro . It
w a s th e p u r p o s e
o f this s tu d y to
a fte r a 5 0 p e r c e n t s o r b ito l rin se w e r e th e n
ta k en .
A p p r o x im a t e ly
one
hour
c o m p le m e n t th e p r e v io u s in v itr o stu d ies
la te r , a s u cr o s e m o u t h
w it h in v iv o d e t e r m in a tio n s o f a c id p o
g iv e n a n d p H v a lu e s w e r e d e t e r m in e d .
rin se w a s a g a in
te n tia ls p r o d u c e d in th e d e n ta l p la q u e b y s o r b ito l a n d s u cr o se rinses. METHOD
RESULTS
T a b l e 1 sh o w s th e d is t r ib u t io n o f th e 31 in d iv id u a ls te s te d , a c c o r d in g to th e m in i-
C a r ie s a c tiv e in d iv id u a ls ( n a v a l r e c r u i t s ) , a v e r a g e a g e 18 y ea rs, w e r e s c r e e n e d fo r th is s tu d y . D e n t a l p la q u e p H d e t e r m in a tio n s w e r e m a d e w it h a C o le m a n v a c u u m t u b e p o t e n t io m e t e r 8 b e fo r e a n d a t 5 , 10, 15 a n d 2 0 m in u t e in te rv a ls a ft e r a o n e m in u t e 5 0 p e r c e n t s u cr o se m o u t h rin se. A t e a c h tim e in te r v a l, f o u r p la q u e p H d e
6
. C r o w le y , M . C ., a n d o th e rs . C o m p a r a t iv e f e r m e n ta b ility o f s o r b it o l, g lu c o s e a n d g ly c e r o l b y c o m m o n o r a l m ic r o o r g a n is m s . J .A .D .A . 52:148 F e b . 1956. 7 . S h ock ley , T. E.; R a n dles, C . I., a n d D o d d , M . C . F e rm e n ta tio n o f s o r b it o l b y ce r ta in a c i d o g e n i c ora l m ic r o o r g a n is m s . J .D . Res. 35:233 A p r il 1956.
8
. F o sd ick , L. S .; C a m p a ig n e , E. E., a n d F an ch er, O . Rate o f a c id fo r m a t io n in ca r io u s a r e a s : e t i o l o g y o f d e n ta l c a r ie s . Illin ois D .J. 10:85 M a rc h 1941.
FOSDICK AND OTHERS . . .VOLUME 55, AUGUST 1957 • 193
Table 2 • Com parison o f a v e ra g e minimum pH values, by quadrants, during the 20 minute interval a fte r sucrose and sorbitol mouth rinses in 31 caries-a ctive individuals
val
fo r
b o th
s u cr o se
and
s o r b it o l
a re
s h o w n in T a b le s 3 a n d 4 . T h e s e p H r e a d in gs w e r e r o u n d e d t o th e n e a r e s t te n th
A ve ra g e minimum pH values Q uadrant Sucrose
Sorbitol
5.77 5.79 5.66 5.60
6.64 6.72 6.72 6.70
a n d p lo t t e d
(se e illu s t r a t io n ) . I t s h o u ld
b e n o t e d th a t th ese a v e r a g e v a lu e s a re m u c h h ig h e r th a n th e a v e r a g e m in im u m
Upper lo w e r Low er Upper
right right left left
pH
v a lu e s
b ecau se
th e
m in im u m
pH
v a lu e s d id n o t o c c u r at ther s a m e tim e in te rv a ls a n d th e fr e q u e n c y o f lo w p H
N o t e : The o v e r -a ll a v e r a g e m in im u m pH v a lu e s, w ith o u t r e f e r e n c e t o th e q u a d r a n t b r e a k d o w n o f t h e in d i v id u a l r e a d in g s , a ft e r s u c r o s e w as 5.38 a n d a ft e r s o r b it o l w as 6.55.
r e a d in g s
v a r ie d
w ith
ea ch
in d iv id u a l.
H e n c e , th e h ig h e r in d iv id u a l p H re a d in g s w o u l d te n d
t o e le v a t e th e a v e r a g e p H
r e a d in g s a t e a c h tim e in te rv a l. A t e a c h tim e in te r v a l, p la q u e w a s r e m u m p H v a lu e s a tt a in e d f o r e a c h q u a d
m o v e d f r o m e a c h q u a d r a n t in th e f o l l o w
r a n t a ft e r th e
in g o r d e r :
s u cr o s e m o u t h
rin se.
In
u p p e r r ig h t q u a d r a n t , lo w e r
e a c h q u a d r a n t , th e p e r c e n t a g e o f in d i
r ig h t q u a d r a n t , lo w e r le f t q u a d r a n t , a n d
v id u a ls f a l lin g in t o v a r io u s p H ra n g e s is
upper
n o te d . M o s t s u b je c ts , a ft e r s u cro se rinses,
s h o w s th a t th e a v e r a g e p H
c o n s is te n tly p r o d u c e d
e a c h q u a d r a n t w e r e in itia lly a t p H 6 .6 b e
pH
v a lu e s b e lo w
le f t
q u a d ra n t.
The
illu s tra tio n r e a d in g s f o r
6 .0 in s e v e ra l q u a d r a n t s . A l l in d iv id u a ls
f o r e th e o n e m in u te 5 0 p e r c e n t s u cro se
p r o d u c e d a n a c id p o t e n t ia l o f p H 5 .6 o r
m o u th
b e lo w
tio n s in p H a ft e r s u cr o s e o c c u r r e d s o m e
a t le a s t o n c e
a ft e r s u cr o se ,
and
rin se. T h e m o s t e x t r e m e r e d u c
m a n y p r o d u c e d h ig h a c id itie s in sev era l
w h ere b e tw e e n 5 a n d
q u a d r a n ts .
m ost
V a lu e s
b e lo w
pH
6 .0
w ere
n e v e r r e a c h e d a ft e r s o rb ito l.
10 m in u te s . T h e
r e d u c t io n
in
pH
c u r r e d in th e u p p e r le f t q u a d r a n t
T a b le 2 re v e a ls th e a v e r a g e m in im u m pH
p r e c ip it o u s
oc (p H
5 . 7 ) . M o s t lik ely , i f a ll th e p H d e t e r m in a
v a lu e s o f th e 31 in d iv id u a ls su b se
tio n s b e t w e e n th e 5 a n d 10 m in u t e in te r
q u e n t t o th e s u cr o s e a n d s o r b ito l m o u t h
v a l c o u ld h a v e b e e n d e t e r m in e d s im u l
rinses.
t a n e o u s ly , th e p H d r o p w o u l d h a v e b e e n
T h is
t a b le
sh ow s
th e
a verage
m in im u m p H v a lu e s b y q u a d r a n ts a n d th e
equal
in
o v e r -a ll a v e r a g e m i n im u m p H v a lu e s f o r
lo w e r
r ig h t
th e 31 in d iv id u a ls w it h o u t r e fe r e n c e t o
p r o b a b ly d r o p p e d t o th e s a m e le v e l as
ea ch
qu a d ra n t.
and
lo w e r
U pper le ft
rig h t,
q u a d r a n ts
th e q u a d r a n t b r e a k d o w n o f th e in d iv id u a l p H re a d in g s . T h e a v e r a g e m in im u m p H f o r e a c h q u a d r a n t w a s c a lc u la t e d f r o m th e r a w d a t a b y s e le c t in g th e lo w e s t p H r e a d in g o c c u r r in g f o r e a c h in d iv id u a l in
T ab le 3 • A ve ra g e pH readings by quadrants (31 individuals) b efo re and during the 20 minute interval a fte r a 1 minute 50 per cent sucrose mouth rinse
a g iv e n q u a d r a n t a t a n y tim e d u r in g th e
20 m in u te p e r i o d a ft e r th e rin s e s; th e m e a n o f t h e 31 r e a d in g s w a s th e n c a lc u
Q uadrant
0
5
10
15
20
right
6.61
6.15
5.97
6.06
6.19
right
6.64
5.91
6.03
6.09
6.21
left
6.62
5.82
5.93
6.07
6.23
la te d . T h e o v e r -a ll a v e r a g e m in im u m p H v a lu e s
w ere
sim ila r ly
d e t e r m in e d ,
but
d iffe r e d o n ly in th a t th e lo w e s t p H r e a d in g o c c u r r in g f o r e a c h in d iv id u a l in a n y q u a d r a n t w a s s e le cte d . T h e o v e r - a ll a v e r a g e m in im u m p H v a lu e a ft e r su crose w a s 5 .3 8 a n d a ft e r s o r b ito l w a s 6 .5 5 .
A v. pH upper A v. pH lo w e r A v. pH lo w e r A v. pH upper
M ean time a fte r 1 minute rinse with sucrose 50 per cent
left
6.64
5.73
5.84
6.07
6.12
6.63
5.90
5.94
6.07
6.19
T h e m e a n p H r e a d in g s f o r e a c h q u a d ra n t in 31 in d iv id u a ls a t e a c h tim e in te r
Total
194 • THE JO U R N A L OF THE A M E R IC A N DENTAL A SSO C IA T IO N
T a b le 4
• A v e ra g e
in d iv id u a ls ) a fte r a
b e fo re
pH and
r e a d in g s d u r in g
by
q u a d ra n ts
(31
1 m in u te 5 0 p e r c e n t s o r b i t o l m o u t h rin s e M e a n tim e a f t e r 1 m in u te r in s e w it h s o r b i t o l 5 0 p e r c e n t
Q u a d ra n t
0
5
10
15
j 20
Av. pH u p p e r rig h t
6 .7 6
6.8 9
6 .8 7
6.8 7
6.8 8
6.71
6 .8 6
'6 . 8 8
6.8 7
6.9 7
6 .6 4
6 .8 5
6.9 0
6 .9 0
6.8 9
6 .7 7
6 .9 2
6.8 5
6.8 7
6 .8 6
6.7 2
6.8 8
6.8 8
6.8 8
6.9 0
Av. pH l o w e r r ig h t Av. pH l o w e r le ft Av. pH u p p e r left T o ta l
D IS C U S S IO N
t h e 2 0 m in u te in t e r v a l
the upper left, but this could not be de tected because, at subsequent time inter vals, upper right, lower right, and lower left quadrant had already passed through the stage of greatest acidity and started to approach the initial pH reading. For purposes o f simplicity, pH readings for each time interval were plotted as occur ring at 5, 10, 15 and 20 minutes. At the 20 minute interval after the sucrose rinse, none of the quadrants exhibited pH values greater than 6.2 and therefore did not approach the initial readings of 6.6. Plots of the average pH readings at each time interval after sorbitol showed that although there was a slight variation in the average plaque pH readings before the sorbitol rinse by quadrants (approxi mately 0.2 pH units), the average pH readings for each postrinse time interval in each quadrant increased to 6.9 and were maintained at that level for 20 minutes. Twenty o f the 31 caries active indi viduals were again given a one minute 50 per cent sucrose mouth rinse at ap proximately one hour after the sorbitol mouth rinse. All produced considerable amounts of acid with pH readings con siderably lower than those after sorbitol rinses. Eighteen o f these 20 individuals dropped to below pH 6.0 at some time during the 20 minute interval after the sucrose mouth rinse.
There was a minor variation in the day to day prerinse mean plaque pH values ( Tables 3 and 4 ). This can be accounted for by the method of pH measurement and clearly demonstrates that the varia tion o f mean plaque acidities from quad rant to quadrant and from corresponding quadrant to quadrant on successive days is slight. This consistency of results in mean plaque sampling before sucrose and sorbitol rinses in the same individuals in dicates the reliability of the testing methods. A comparison of pH determinations after sucrose and sorbitol mouth rinses in 31 individuals demonstrates clearly that sorbitol is not metabolized to acid by den tal plaque during the 20 minute period. Indeed, sorbitol produced a consistent elevation of plaque pH over initial read ings. The same 31 individuals produced acidities sufficient to decalcify the hard substance of the teeth after the sucrose rinse, and all produced an acid potential of at least pH 5.6 at some time during the 20 minute interval. The average mini mum pH (all quadrants combined) after
TIM EINM IN U TESFO LLO W IN GR IN SES C o m p a r is o n o f a v e r a g e p H r e a d in g s fo r each q u a d r a n t a t five m inute in te rv a ls a fte r a 50 p e r ce n t su c ro se a n d so rb ito l m outh rinse in 31 ca rie sa c tiv e in d iv id u a ls
FO SD IC K A N D OTHERS . . . VO LUM E 55, AUGUST 1957 • 195
the sucrose rinse was 5.38 and for sorbitol was 6.6. pH values were determined for the sucrose and sorbitol solutions. The pH of the sorbitol solution was 5.5 and for sucrose, 6.6. It seems doubtful, therefore, that the differences in action by the den tal plaque on sucrose and sorbitol could be accounted for by the pH of the sorbitol and sucrose solutions per se but must be due to the metabolism of the microorgan isms in the dental plaque. T o substantiate the fact that the 31 in dividuals selected were consistent acid producers, 20 were given an additional sucrose mouth rinse at approximately one hour after the sorbitol rinse. All produced greater acidities than with sorbitol and 18 o f the 20 dropped below pH 6.0. H ow ever, the drops were not as severe as after the initial sucrose rinses, and it seems that residual sorbitol in the plaque may have had some effect in preventing a greater drop in pH levels. This study bears out the in vitro studies o f Grubb, Crowley and co-workers and Shockley and associates and provides further evidence that the in vitro study of acid production by oral microflorae gives an excellent indication of the actual carbohydrate metabolism in the dental plaque. Although cyclamate and saccharin are effective sweetening agents and can be used as sugar substitutes, they are not foods and do not have any nutritional value. However, in the rat, sorbitol ap proaches glucose in caloric value.4 It has been reported that sorbitol has cathartic properties in quantities over 50 Gm.® This action is probably due to its delayed
absorption in the intestine and is based on the osmotic transfer of water into the bowel. Although sorbitol cannot replace sugar completely in the normal diet, it may be used effectively in confections, in limited amounts, in certain persons with rampant caries. SU M M A R Y
1. Plaque pH determinations were made after sucrose and sorbitol mouth rinses. 2. Slight variation was noted when the average pH readings for each quad rant were compared before sucrose and sorbitol mouth rinses. 3. The average minimum pH (all quadrants combined) during the 20 minute interval after a one minute 50 per cent sucrose mouth rinse was pH 5.38 and after sorbitol was 6.55. 4. All individuals produced an acid potential o f at least pH 5.6 at some time during the 20 minute interval after the sucrose rinse. None of these individuals produced pH values below pH 6.0 at any time after sorbitol mouth rinses. 5. For each quadrant, the average pH value during the 20 minute period after a one minute 50 per cent sorbitol mouth rinse was 6.9. The average pH value for each quadrant during the 20 minute period after a sucrose rinse dropped precipitously. 6. I f acid production in the dental plaque after ingestion of fermentable carbohydrate is responsible for the initia tion of caries, the inclusion of sorbitol in moderate amounts in diets for individuals with rampant caries seems rational.
o r ig in a l v e r t ic a l d im e n s io n , o c c lu s a l p la n e
o r ig in a l p la n e
a n d t o o t h p o s it io n in e d e n tu lo u s p a tien ts.
d im e n s io n
T h e t e c h n ic u s e d in v o lv e s d e v e lo p m e n t
t o o t h p o s it io n o n th is p la n e . T h e results
o f a f u n c t io n a l v e r t ic a l d im e n s io n as c lo s e
a re f u n c t io n a l a n d esth etic.
and
of
o c c lu s io n
re s to r a tio n
w ith in of
this
n a tu r a l
3 7 8 0 W ils h ir e B o u le v a r d
to th e o r ig in a l as p o s s ib le , lo c a t io n o f th e
A comparison of p H values of in vivo dental plaque after sucrose and sorbitol mouth rinses
L e o n a r d S . F o s d ic k , * P h .D ., C h i c a g o ; H a r o l d R . E n g la n d e r D .D .S ., M . P . H . ; K i r k C . H o e r m a n ,\ D .D .S ., M .S . , G r e a t L a k e s , III., a n d R o b e r t G . K esel,% D .D .S ., M .S ., C h ic a g o
I t is f e lt b y m a n y in v e s tig a to rs 1' 3 th a t
T h e r e is s tr o n g in v itro e v id e n c e th a t
d e n ta l ca rie s is in itia t e d a n d c o n t in u e d b y
s o r b ito l is n o t r e a d ily fe r m e n t e d b y a c id o -
th e p r o d u c t i o n o f a c i d in th e d e n t o b a c -
g e n ic m o u t h o rg a n is m s . G r u b b 5 d e m o n
te ria l p la q u e d u r in g a s h o r t p e r io d a ft e r
s tra te d th a t s o r b ito l w a s fe r m e n t e d m o r e
th e
in g e s tio n
of
fe r m e n t a b le
ca rb o
s lo w ly
th a n
s u cro se
strain s
of
and
d e x tr o s e
L a c to b a c il lu s
by
h y d ra te s. I f a n o n f e r m e n t a b le s w e e t s u b
v a r io u s
a c id o
s ta n ce c o u l d b e s u b s titu te d f o r s u cro se o r
p h ilu s, o r a l s t r e p t o c o c c i, yea sts, a n d m i x
o t h e r fe r m e n t a b le c a r b o h y d r a t e s , s ig n ifi
tu res o f yeasts a n d L . a c id o p h ilu s in v a
c a n t r e d u c t io n s in th e in c id e n c e o f d e n ta l
riou s m e d ia . I t w a s b e lie v e d th a t s o rb ito l
ca rie s m ig h t b e a tta in e d . S u c h a p o s s i
is o x id iz e d t o s o rb o s e a n d G r u b b d e m o n -
b ility exists w it h th e s u b s titu tio n o f th e h e x a h y d r o x y a lc o h o l, s o r b ito l f o r s u cro se a n d d e x tr o s e in v a r io u s c o n fe c t io n s . S o r b it o l o c c u r s n a t u r a lly in m a n y fru its a n d m a y b e s y n th e tic a lly p r o d u c e d b y th e c a ta ly tic r e d u c t io n o f g lu c o s e . A lt h o u g h s o r b ito l is c o n s id e r e d a n a lc o h o l a n d n o t a
sugar
becau se
it
does
n ot
c o n t a in
a c h a r a c te r is t ic a ld e h y d e o r k e to n e c o n fig u r a t io n , it is a f o o d a n d , as s u ch , c a n b e c o n v e r t e d in to liv e r g ly c o g e n a n d in to g lu c o s e .4 S o r b it o l is u tiliz e d a t a m u c h s lo w e r r a te a ft e r in g e s tio n th a n g lu c o s e ; h o w e v e r , c h ie fly b e c a u s e o f its d e la y e d in te stin a l a b s o r p t io n , its to ta l o x id a t io n app roach es h o u r p e r io d .
th a t o f
g lu c o s e
over
a
24
The o p in io n s o r a ssertion s c o n t a in e d in this a r t ic le a re th e p r iv a t e o n e s o f th e w riter a n d a r e n ot t o b e c o n s tru e d as o ffic ia l o r r e fle c tin g th e v iew s o f th e N avy D e p a rtm e n t o r th e n a va l s e r v ic e a t la r g e . of
* P r o fe s s o r o f ch e m istry , N orth w estern U n iversity S c h o o l D entistry.
fL ie u te n a n t c o m m a n d e r ( D C ) , U n ited S ta tes N avy, d e n ta l re s e a r ch fa c ilit y , d e n ta l d e p a r t m e n t , U. S. N a v al T ra ining C o r p s . of
{P r o fe s s o r o f d en tistry , D entistry.
U n iv ersity
of
Illin ois C o l l e g e
1._ S te p h a n ,_ R. M . In tra -ora l h y d r o g e n - io n c o n c e n tra tio n s a s s o c ia t e d w ith d e n ta l c a r ie s a c t iv it y . J .D . Res. 23:257 A u g . 1944. 2. S tra lfo rs, A . S tu d ies o f m ic r o b io l o g y o f ca rie s . II. A c i d fe r m e n t a t io n in d e n ta l p la q u e s in situ c o m p a r e d with la c t o b a c illu s co u n ts . J .D . Res. 27:576 O c t . 1948. 3. M o o r e , B. W ., a n d o th e rs . F orm a tion o f la c t ic a c id in d e n ta l p la q u e s . I. C a r ie s -a c t iv e in d iv id u a ls . J.D Res. 35:778 O c t . 1956. 4. W ic k , A . N .; A lm e n , M . C ., M e t a b o lis m o f s o r b i t o l. J .A m .P h a r m . 40:542 N o v . 1951.
and J oseph , L. A . (S c ie n t . e d . )
5. G r u b b , T. C . S tu d ie s o n fe r m e n t a t io n o f s o r b it o l b y o r a l m ic r o o r g a n is m s . J .D . Res. 24:3 ! F e b . 1945.
192 • THE JOURNAL OFTHE AMERICAN DENTAL ASSOCIATION
T a b le 1
• D is tr ib u tio n o f 31
c a r ie s a c t iv e
in d iv id u a ls a c c o r d i n g
to
m inimum
pH
v a lu e s
a t t a in e d d u rin g t h e 2 0 m in u te p e r i o d a f t e r a s u c r o s e m ou th rin se
Upper right quadrant
pH
< 5 .3 5.4— 5.6 5.7— 5.9 > 6 .0
Low er left quadrant
Upper left quadrant
N o.
| Per cent
N o.
Per cent
No.
Per cent
No.
Per cent
2 11 7 11
6.5 35.5 22.6 35.5
1 12 8 10
3.2 38.7 25.8 32.3
5 7 12 7
16.1 22.6 38.7 22.6
4 16 6 5
12.9 51.6 19.4 16.1
31
Total
Low er right quadrant
100
31
100
31
100 p e r c e n t o f p H v a lu e s a ft e r s o r b it o l rinses w e re >
100
31
100
6.0 in a ll q u a d ra n ts .
s tra te d th a t b a c t e r ia l e n zy m e s fin d it d iffi
te r m in a tio n s w e r e m a d e , o n e f r o m e a ch
c u lt t o ca u s e th e f u r t h e r d e c o m p o s it io n
p o s t e r io r
o f s o rb o s e .
s id e re d
C r o w le y ,
H arn er,
B en n ett
and
Jay6
q u a d ra n t. any
P la q u e
s u b s ta n ce
w as
n o r m a lly
con fo u n d
a r o u n d th e te e th re g a rd le s s o f its o r ig in .
c o m p a r e d th e in v itr o fe r m e n t a b ilit y o f
T h is
s o r b ito l, g ly c e r o l a n d g lu c o s e b y c e r t a in
d e b ris , b u t n o t f o o d , c a lc u lu s o r d e c a y .
o r a l m ic r o o r g a n is m s ( la c t o b a c illi, s tr e p to
S u ffic ie n t p la q u e t o c o v e r th e h e a d o f a
c o c c i , s t a p h y lo c o c c i a n d y e a s t ) . W it h in
d is c o id in s tr u m e n t w a s r e m o v e d f r o m th e
in c lu d e d
m a t e r ia
a lb a
and
o th e r
2 4 h o u r s , th e v a s t m a jo r it y o f th e c o m
b u c c o p r o x im a l s u rfa ce s o f th e m o la r s a n d ,
m o n o r a l m ic r o o r g a n is m s tested p r o d u c e d
w h e n e v e r p o s s ib le , w a s ta k e n f r o m
s u ffic ie n t a c id f r o m g lu c o s e t o d e c a lc ify
s a m e t o o t h in e a c h p o s t e r io r q u a d r a n t at
th e
e n a m e l; h o w e v e r , th is w a s n o t tr u e o f
e a c h tim e in te r v a l t h r o u g h o u t th e stu d y.
s o r b ito l. A f t e r o n e w e e k th e m e a n p H o f
O v e r 1 00 in d iv id u a ls w e r e s c r e e n e d b u t
s o r b it o l- la c t o b a c illi c u ltu r e s w a s 5 .1 , b u t
o n ly 31 p r o d u c e d a n a c id p o t e n t ia l o f p H
it w a s c o n c l u d e d
th a t s o r b ito l w a s n o t
5 .6 o r b e lo w a t s o m e tim e d u r in g th e 20
lik e ly t o b e r e t a in e d in th e m o u t h f o r so
m in u te in te r v a l a n d th ese w e r e s e le cte d
lo n g a tim e .
f o r s tu d y .
S h o c k le y , R a n d le s a n d D o d d 7 d e m o n
E a c h in d iv id u a l w a s in s t r u c te d t o r e
s tra te d th a t th e m ix e d flo r a o f s a liv a h a d
tu rn a t a p p r o x im a t e ly th e s a m e tim e th e
lit tle t e n d e n c y t o fe r m e n t s o r b ito l d u r in g
f o l l o w i n g d a y . S im ila r p H d e te r m in a tio n s
s h o r t p e r io d s o f in c u b a t io n in v itro . It
w a s th e p u r p o s e
o f this s tu d y to
a fte r a 5 0 p e r c e n t s o r b ito l rin se w e r e th e n
ta k en .
A p p r o x im a t e ly
one
hour
c o m p le m e n t th e p r e v io u s in v itr o stu d ies
la te r , a s u cr o s e m o u t h
w it h in v iv o d e t e r m in a tio n s o f a c id p o
g iv e n a n d p H v a lu e s w e r e d e t e r m in e d .
rin se w a s a g a in
te n tia ls p r o d u c e d in th e d e n ta l p la q u e b y s o r b ito l a n d s u cr o se rinses. METHOD
RESULTS
T a b l e 1 sh o w s th e d is t r ib u t io n o f th e 31 in d iv id u a ls te s te d , a c c o r d in g to th e m in i-
C a r ie s a c tiv e in d iv id u a ls ( n a v a l r e c r u i t s ) , a v e r a g e a g e 18 y ea rs, w e r e s c r e e n e d fo r th is s tu d y . D e n t a l p la q u e p H d e t e r m in a tio n s w e r e m a d e w it h a C o le m a n v a c u u m t u b e p o t e n t io m e t e r 8 b e fo r e a n d a t 5 , 10, 15 a n d 2 0 m in u t e in te rv a ls a ft e r a o n e m in u t e 5 0 p e r c e n t s u cr o se m o u t h rin se. A t e a c h tim e in te r v a l, f o u r p la q u e p H d e
6
. C r o w le y , M . C ., a n d o th e rs . C o m p a r a t iv e f e r m e n ta b ility o f s o r b it o l, g lu c o s e a n d g ly c e r o l b y c o m m o n o r a l m ic r o o r g a n is m s . J .A .D .A . 52:148 F e b . 1956. 7 . S h ock ley , T. E.; R a n dles, C . I., a n d D o d d , M . C . F e rm e n ta tio n o f s o r b it o l b y ce r ta in a c i d o g e n i c ora l m ic r o o r g a n is m s . J .D . Res. 35:233 A p r il 1956.
8
. F o sd ick , L. S .; C a m p a ig n e , E. E., a n d F an ch er, O . Rate o f a c id fo r m a t io n in ca r io u s a r e a s : e t i o l o g y o f d e n ta l c a r ie s . Illin ois D .J. 10:85 M a rc h 1941.
FOSDICK AND OTHERS . . .VOLUME 55, AUGUST 1957 • 193
Table 2 • Com parison o f a v e ra g e minimum pH values, by quadrants, during the 20 minute interval a fte r sucrose and sorbitol mouth rinses in 31 caries-a ctive individuals
val
fo r
b o th
s u cr o se
and
s o r b it o l
a re
s h o w n in T a b le s 3 a n d 4 . T h e s e p H r e a d in gs w e r e r o u n d e d t o th e n e a r e s t te n th
A ve ra g e minimum pH values Q uadrant Sucrose
Sorbitol
5.77 5.79 5.66 5.60
6.64 6.72 6.72 6.70
a n d p lo t t e d
(se e illu s t r a t io n ) . I t s h o u ld
b e n o t e d th a t th ese a v e r a g e v a lu e s a re m u c h h ig h e r th a n th e a v e r a g e m in im u m
Upper lo w e r Low er Upper
right right left left
pH
v a lu e s
b ecau se
th e
m in im u m
pH
v a lu e s d id n o t o c c u r at ther s a m e tim e in te rv a ls a n d th e fr e q u e n c y o f lo w p H
N o t e : The o v e r -a ll a v e r a g e m in im u m pH v a lu e s, w ith o u t r e f e r e n c e t o th e q u a d r a n t b r e a k d o w n o f t h e in d i v id u a l r e a d in g s , a ft e r s u c r o s e w as 5.38 a n d a ft e r s o r b it o l w as 6.55.
r e a d in g s
v a r ie d
w ith
ea ch
in d iv id u a l.
H e n c e , th e h ig h e r in d iv id u a l p H re a d in g s w o u l d te n d
t o e le v a t e th e a v e r a g e p H
r e a d in g s a t e a c h tim e in te rv a l. A t e a c h tim e in te r v a l, p la q u e w a s r e m u m p H v a lu e s a tt a in e d f o r e a c h q u a d
m o v e d f r o m e a c h q u a d r a n t in th e f o l l o w
r a n t a ft e r th e
in g o r d e r :
s u cr o s e m o u t h
rin se.
In
u p p e r r ig h t q u a d r a n t , lo w e r
e a c h q u a d r a n t , th e p e r c e n t a g e o f in d i
r ig h t q u a d r a n t , lo w e r le f t q u a d r a n t , a n d
v id u a ls f a l lin g in t o v a r io u s p H ra n g e s is
upper
n o te d . M o s t s u b je c ts , a ft e r s u cro se rinses,
s h o w s th a t th e a v e r a g e p H
c o n s is te n tly p r o d u c e d
e a c h q u a d r a n t w e r e in itia lly a t p H 6 .6 b e
pH
v a lu e s b e lo w
le f t
q u a d ra n t.
The
illu s tra tio n r e a d in g s f o r
6 .0 in s e v e ra l q u a d r a n t s . A l l in d iv id u a ls
f o r e th e o n e m in u te 5 0 p e r c e n t s u cro se
p r o d u c e d a n a c id p o t e n t ia l o f p H 5 .6 o r
m o u th
b e lo w
tio n s in p H a ft e r s u cr o s e o c c u r r e d s o m e
a t le a s t o n c e
a ft e r s u cr o se ,
and
rin se. T h e m o s t e x t r e m e r e d u c
m a n y p r o d u c e d h ig h a c id itie s in sev era l
w h ere b e tw e e n 5 a n d
q u a d r a n ts .
m ost
V a lu e s
b e lo w
pH
6 .0
w ere
n e v e r r e a c h e d a ft e r s o rb ito l.
10 m in u te s . T h e
r e d u c t io n
in
pH
c u r r e d in th e u p p e r le f t q u a d r a n t
T a b le 2 re v e a ls th e a v e r a g e m in im u m pH
p r e c ip it o u s
oc (p H
5 . 7 ) . M o s t lik ely , i f a ll th e p H d e t e r m in a
v a lu e s o f th e 31 in d iv id u a ls su b se
tio n s b e t w e e n th e 5 a n d 10 m in u t e in te r
q u e n t t o th e s u cr o s e a n d s o r b ito l m o u t h
v a l c o u ld h a v e b e e n d e t e r m in e d s im u l
rinses.
t a n e o u s ly , th e p H d r o p w o u l d h a v e b e e n
T h is
t a b le
sh ow s
th e
a verage
m in im u m p H v a lu e s b y q u a d r a n ts a n d th e
equal
in
o v e r -a ll a v e r a g e m i n im u m p H v a lu e s f o r
lo w e r
r ig h t
th e 31 in d iv id u a ls w it h o u t r e fe r e n c e t o
p r o b a b ly d r o p p e d t o th e s a m e le v e l as
ea ch
qu a d ra n t.
and
lo w e r
U pper le ft
rig h t,
q u a d r a n ts
th e q u a d r a n t b r e a k d o w n o f th e in d iv id u a l p H re a d in g s . T h e a v e r a g e m in im u m p H f o r e a c h q u a d r a n t w a s c a lc u la t e d f r o m th e r a w d a t a b y s e le c t in g th e lo w e s t p H r e a d in g o c c u r r in g f o r e a c h in d iv id u a l in
T ab le 3 • A ve ra g e pH readings by quadrants (31 individuals) b efo re and during the 20 minute interval a fte r a 1 minute 50 per cent sucrose mouth rinse
a g iv e n q u a d r a n t a t a n y tim e d u r in g th e
20 m in u te p e r i o d a ft e r th e rin s e s; th e m e a n o f t h e 31 r e a d in g s w a s th e n c a lc u
Q uadrant
0
5
10
15
20
right
6.61
6.15
5.97
6.06
6.19
right
6.64
5.91
6.03
6.09
6.21
left
6.62
5.82
5.93
6.07
6.23
la te d . T h e o v e r -a ll a v e r a g e m in im u m p H v a lu e s
w ere
sim ila r ly
d e t e r m in e d ,
but
d iffe r e d o n ly in th a t th e lo w e s t p H r e a d in g o c c u r r in g f o r e a c h in d iv id u a l in a n y q u a d r a n t w a s s e le cte d . T h e o v e r - a ll a v e r a g e m in im u m p H v a lu e a ft e r su crose w a s 5 .3 8 a n d a ft e r s o r b ito l w a s 6 .5 5 .
A v. pH upper A v. pH lo w e r A v. pH lo w e r A v. pH upper
M ean time a fte r 1 minute rinse with sucrose 50 per cent
left
6.64
5.73
5.84
6.07
6.12
6.63
5.90
5.94
6.07
6.19
T h e m e a n p H r e a d in g s f o r e a c h q u a d ra n t in 31 in d iv id u a ls a t e a c h tim e in te r
Total
194 • THE JO U R N A L OF THE A M E R IC A N DENTAL A SSO C IA T IO N
T a b le 4
• A v e ra g e
in d iv id u a ls ) a fte r a
b e fo re
pH and
r e a d in g s d u r in g
by
q u a d ra n ts
(31
1 m in u te 5 0 p e r c e n t s o r b i t o l m o u t h rin s e M e a n tim e a f t e r 1 m in u te r in s e w it h s o r b i t o l 5 0 p e r c e n t
Q u a d ra n t
0
5
10
15
j 20
Av. pH u p p e r rig h t
6 .7 6
6.8 9
6 .8 7
6.8 7
6.8 8
6.71
6 .8 6
'6 . 8 8
6.8 7
6.9 7
6 .6 4
6 .8 5
6.9 0
6 .9 0
6.8 9
6 .7 7
6 .9 2
6.8 5
6.8 7
6 .8 6
6.7 2
6.8 8
6.8 8
6.8 8
6.9 0
Av. pH l o w e r r ig h t Av. pH l o w e r le ft Av. pH u p p e r left T o ta l
D IS C U S S IO N
t h e 2 0 m in u te in t e r v a l
the upper left, but this could not be de tected because, at subsequent time inter vals, upper right, lower right, and lower left quadrant had already passed through the stage of greatest acidity and started to approach the initial pH reading. For purposes o f simplicity, pH readings for each time interval were plotted as occur ring at 5, 10, 15 and 20 minutes. At the 20 minute interval after the sucrose rinse, none of the quadrants exhibited pH values greater than 6.2 and therefore did not approach the initial readings of 6.6. Plots of the average pH readings at each time interval after sorbitol showed that although there was a slight variation in the average plaque pH readings before the sorbitol rinse by quadrants (approxi mately 0.2 pH units), the average pH readings for each postrinse time interval in each quadrant increased to 6.9 and were maintained at that level for 20 minutes. Twenty o f the 31 caries active indi viduals were again given a one minute 50 per cent sucrose mouth rinse at ap proximately one hour after the sorbitol mouth rinse. All produced considerable amounts of acid with pH readings con siderably lower than those after sorbitol rinses. Eighteen o f these 20 individuals dropped to below pH 6.0 at some time during the 20 minute interval after the sucrose mouth rinse.
There was a minor variation in the day to day prerinse mean plaque pH values ( Tables 3 and 4 ). This can be accounted for by the method of pH measurement and clearly demonstrates that the varia tion o f mean plaque acidities from quad rant to quadrant and from corresponding quadrant to quadrant on successive days is slight. This consistency of results in mean plaque sampling before sucrose and sorbitol rinses in the same individuals in dicates the reliability of the testing methods. A comparison of pH determinations after sucrose and sorbitol mouth rinses in 31 individuals demonstrates clearly that sorbitol is not metabolized to acid by den tal plaque during the 20 minute period. Indeed, sorbitol produced a consistent elevation of plaque pH over initial read ings. The same 31 individuals produced acidities sufficient to decalcify the hard substance of the teeth after the sucrose rinse, and all produced an acid potential of at least pH 5.6 at some time during the 20 minute interval. The average mini mum pH (all quadrants combined) after
TIM EINM IN U TESFO LLO W IN GR IN SES C o m p a r is o n o f a v e r a g e p H r e a d in g s fo r each q u a d r a n t a t five m inute in te rv a ls a fte r a 50 p e r ce n t su c ro se a n d so rb ito l m outh rinse in 31 ca rie sa c tiv e in d iv id u a ls
FO SD IC K A N D OTHERS . . . VO LUM E 55, AUGUST 1957 • 195
the sucrose rinse was 5.38 and for sorbitol was 6.6. pH values were determined for the sucrose and sorbitol solutions. The pH of the sorbitol solution was 5.5 and for sucrose, 6.6. It seems doubtful, therefore, that the differences in action by the den tal plaque on sucrose and sorbitol could be accounted for by the pH of the sorbitol and sucrose solutions per se but must be due to the metabolism of the microorgan isms in the dental plaque. T o substantiate the fact that the 31 in dividuals selected were consistent acid producers, 20 were given an additional sucrose mouth rinse at approximately one hour after the sorbitol rinse. All produced greater acidities than with sorbitol and 18 o f the 20 dropped below pH 6.0. H ow ever, the drops were not as severe as after the initial sucrose rinses, and it seems that residual sorbitol in the plaque may have had some effect in preventing a greater drop in pH levels. This study bears out the in vitro studies o f Grubb, Crowley and co-workers and Shockley and associates and provides further evidence that the in vitro study of acid production by oral microflorae gives an excellent indication of the actual carbohydrate metabolism in the dental plaque. Although cyclamate and saccharin are effective sweetening agents and can be used as sugar substitutes, they are not foods and do not have any nutritional value. However, in the rat, sorbitol ap proaches glucose in caloric value.4 It has been reported that sorbitol has cathartic properties in quantities over 50 Gm.® This action is probably due to its delayed
absorption in the intestine and is based on the osmotic transfer of water into the bowel. Although sorbitol cannot replace sugar completely in the normal diet, it may be used effectively in confections, in limited amounts, in certain persons with rampant caries. SU M M A R Y
1. Plaque pH determinations were made after sucrose and sorbitol mouth rinses. 2. Slight variation was noted when the average pH readings for each quad rant were compared before sucrose and sorbitol mouth rinses. 3. The average minimum pH (all quadrants combined) during the 20 minute interval after a one minute 50 per cent sucrose mouth rinse was pH 5.38 and after sorbitol was 6.55. 4. All individuals produced an acid potential o f at least pH 5.6 at some time during the 20 minute interval after the sucrose rinse. None of these individuals produced pH values below pH 6.0 at any time after sorbitol mouth rinses. 5. For each quadrant, the average pH value during the 20 minute period after a one minute 50 per cent sorbitol mouth rinse was 6.9. The average pH value for each quadrant during the 20 minute period after a sucrose rinse dropped precipitously. 6. I f acid production in the dental plaque after ingestion of fermentable carbohydrate is responsible for the initia tion of caries, the inclusion of sorbitol in moderate amounts in diets for individuals with rampant caries seems rational.