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A Multiple-Examiner Clinical Evaluation of a Sodium Fluoride Dentifrice
A multiple-examiner clinical evaluation of a sodium fluoride dentifrice
P. R. Weisenstein, DDS W. A. Zacherl, DDS, MPh, Columbus, Ohio
Either a nontherapeutic d entifrice or a dentifrice containing sodium fluoride was assigned random ly to about 700 suburban schoolchildren for use. The children were examined at the beginning of the study, and then after 9, 16, and 21 months. After 21 months, the two examiners fo un d-sta tis tic a lly significant reductions o f caries in children using the fluoride dentifrice.
D ental researchers have been interested in sodium fluoride as an anticaries agent sin ce the early 1940s. A lthough early clinical studies o f den ti frice system s containing sodium fluoride failed to dem onstrate anticaries effectiven ess,1-2 a latent interest in sodium fluoride dentifrice system s persisted. With the advent o f an effective stan n ous fluoride dentifrice in the m id -1 9 5 0 s and with the ensuing advances in dentifrice techn ol ogy, new dentifrice system s containing sodium fluoride w ere pursued. In 1968, Zacherl3 reported a statistically significant reduction in dental caries with a neutral-pH sodium fluoride dentifrice sy s tem incorporating a new high-beta-phase calcium
pyrophosphate abrasive that is less soluble than ordinary dentifrice abrasives. R eed and King4 in 1970 also reported a statistically significant r e duction in dental caries for the sam e dentifrice system. T h is dentifrice system is the subject o f the clinical evaluation described in this report.
Procedure In this study, 694 children ranging in age from 5 to 15 years were recruited from several elem en tary schools in suburban C olum bus, O hio. F lu o r id e in the com m unal water supply was negligible. T h e children were accepted into the study on a voluntary basis with written consent o f th e parent or guardian. E xam inations o f each ch ild were conducted independently by both authors initially, then after 9 m onths, after 16 m onths, and at the term ination o f th e study after 21 m onths. A supervised brush ing with a nontherapeutic dentifrice preceded the exam inations at each stage o f the study. Both exam iners used a visual-tactile exam ination that was supplem ented by a seven-film bitew ing radiographic series for each child. D M F T (decayed, m issing and filled teeth) and D M F S (decayed, m issing, and filled surfaces) scores were recorded. G enerally recognized criteria for diagnosis o f carious lesion s5 w ere applied by both exam iners. E xam inations were conducted in th e schools with use o f p ortable field equipm ent. JADA, Vol. 84, March 1972 ■ 621
o f a nonstudy dentifrice w as m inim ized because enough dentifrice was given each ch ild to supply th e h ousehold for the duration o f th e study. I f m ore than o n e ch ild in a fam ily p articipated in the study, they w ere assigned the sam e dentifrice.
T h e findings o f o n e o f th e tw o exam iners were used arbitrarily for dentifrice assignm ent. Im m ediately after th e initial visual-tactile exam i nation, each ch ild was assigned on e o f the tw o dentifrices random ly within the strata o f age, sex, and th e visual-tactile D M F S exam ination results. A lthough this clinical evaluation is based on findings in perm anent dentitions, th e findings on deciduous teeth were used in assigning den ti frices to kindergarten children. T h e control and test dentifrices w ere sim ilar in color, flavor, and other properties. T h e form ulations o f the den ti frices are given in T ab le 1. T h e exam iners had no know ledge o f th e den ti frice assigned to each child, and the children had no know ledge o f the identities o f th e dentifrices assigned to them. A ll clinical exam inations and radiographic interpretations w ere m ad e in d e pendently o f previous exam ination records. F rac tured teeth, banded teeth, and teeth extracted for orthodontic reasons w ere not included in the data tabulations. Posterior teeth that w ere e x tracted because o f caries w ere counted as three surfaces and extracted anterior teeth as two sur faces. H ow ever, a lesser num ber o f surfaces than that which w as counted on a previous exam ina tion was never recorded. T oothbrushes and a supply o f th e assigned d en tifrice in co d ed w hite tubes were given each ch ild p eriodically during the study. T h e p ossib le effect
Results and discussion T ab le 2 shows the initial characteristics o f the children who participated during th e various stages o f the study. A ge, D M F T , and D M F S are given as m eans. D esp ite the attrition in the n u m ber o f children, th e tw o dentifrice grou p s c o m p ared favorably throughout th e study. T h e tw o dentifrice groups show n o significant differences in th e initial characteristics for either exam iner at any stage. M ost o f th e ch il dr a t w ho d id not c o m p lete the study had m oved. A sm all num ber w ere absent on th e days o f exam ination. T ab les 3 and 4 show the m ean caries in cre m ents based on the D M F T and D M F S in dexes respectively for both exam iners after th e three stages o f the study. T h e results in term s o f percent reduction are consistent for each exam iner with th e exception o f the nine-m onth v a lu es for E xam iner B. T h e aberrant reductions are attributed to the circum stances under which the nine-m onth exam inations were made. D uring this period, Exam iner B w as in poor health and yet p articipated in th e exam inations because o f th e critical sched u le n ecessitated by a m ultiple-exam iner study. T h e probabilities given are based on a o n e tailed norm al deviate test.6 Exam iner A observed statistically significant ( « = 0 .0 5 ) caries reductions, based on the D M F T index after 16 and 21 m onths with use o f the fluoride dentifrice. E xam iner B found statistically significant caries reduction for th e fluoride dentifrice after 9, 16, and 21 m onths, based on both the D M F T and D M F S indexes.
Table 1 ■ D e n tifric e fo rm u la tio n s. % com position Com ponents
C ontrol den tifrice
Test den tifrice
40.00 1.48 1.38 24.00 33.14
40.00 1.48 1.38 24.00 32.92
Sodium fluoride High-beta-phase calcium pyrophosphate Binders Surfactants Humectants Water, buffers, and flavor
0 22
Ta ble 2 ■ C h a ra c te ris tic s o f c h ild re n c o m p le tin g an in d ica te d p o rtio n o f th e study. Sex No. Stage C hildren starting test Children com pleting 9 m onths Children com pleting 16 months Children com pleting 21 m onths
Male
Age (yrs)
Female
Average
Range
D entifrice C ontrol N eutral-pH NaF C ontrol Neutral-pH NaF C ontrol Neutral-pH NaF C ontrol N eutral-pH NaF
DM FT Exam iner A
DMFS Exam iner B
E xam iner A
Exam iner B
Average
SE M '
Average
SEM
Average
SEM
Average
SEM
348 346 278 270
168 169 141 133
180 177 137 137
9.49 9.39 9.68 9.34
5-15 5-14 5-15 5-14
4.18 4.02 4.35 3.99
0.197 0.204 0.214 0.227
6.24 6.04 6.33 5.94
0.245 0.258 0.264 0 287
6.99 7.01 7.13 6.93
0.357 0.387 0.378 0.430
12.16 11.80 12.28 11.73
0.518 0.552 0.551 0.621
231 234
119 123
112 111
9.68 9.34
5-15 5-14
4.19 4.00
0.220 0.245
6.25 5.85
0.270 0.302
6.81 6.88
0.399 0.454
11.94 11.48
0.546 0.641
196 206
101 95
95 111
9.52 9.38
5-15 5-14
4.09 4.11
0.243 0.263
6.22 5.94
0.310 0.316
6.66 6.97
0.428 0.481
11.78 11.67
0.626 0.677
*SEM: standard erro r o f the mean.
622 ■ JADA, Vol. 84, March 1972
Table 3 ■ D M FT results d u rin g a 2 1 -m o n th p e rio d fo r all ch ild re n w h o co m p le te d th e sp e c ifie d stage o f th e stu d y. Exam iner A Stage
D entifrice
No.
AD M FT*
SEM t
Examiner B
P ro b t
% Reduction
ADMFT
SEM
Prob
% R eduction
0.125 1.19 0.81 0.106 C hildren C ontrol 278 77.8% 1.07 0.2090 0.18 0.090 <0.0001 0.102 10.1% com pleting Neutral-pH 270 NaF 9 m onths 0.174 2.01 1.93 0.129 C hildren 231 C ontrol 0.141 28.0% 1.56 0.127 0.0066 22.4% 1.39 0.0080 234 com pleting Neutral-pH 16 m onths NaF 2.60 0.208 3 40 0.198 C hildren 196 Control 0.0250 1.64 0.165 <0.0001 36.9% 2.90 0.161 14.7% com pleting NeutraJ-pH 206 21 m onths_________NaF__________________________________________________________________________________________________________________ _______ 'A D M F T is the mean increm ent fo r the DM FT index. fSEM is standard erro r of the mean. tP ro b is the probability that a difference as large as or larger than the observed difference between means co u ld have occurred by chance alone.
Table 4 ■ DMFS results during a 21-month period for all children who completed the specified stage o f the study. Examiner A Stage C hildren com pleting 9 m onths C hildren com pleting 16 months C hildren com pleting 21 months
Examiner B
Dentifrice
No.
AD M F S
SEMf
P ro b t
% reduction
AD M F S
SEM
Prob
C ontrol N eutral-pH NaF Control Neutral-pH NaF Control Neutral-pH NaF
278 270
1.96 1.75
0.177 0.166
0.1949
10.7%
1.05 -0.17
0.220 0.181
<0.0001
116.2%
231 234
3.16 2.75
0.204 0.197
13.0%
4.02 2.78
0.348 0.273
0.0026
30.8%
196 206
5.60 4.98
0.310 0.279
11.1%
4.76 2.94
0.407 0.324
<0.0002
38.2%
0.0735
0.0681
% reductio
*AD M FS is the mean increm ent fo r the DMFS index. tS E M is standard error of the mean. {P ro b is the probab ility that a difference as large as o r la rge r than the observed difference between means c o u ld have occurred by chance alone.
Summary and conclusions A neutral-pH dentifrice containing sodium flour id e and high-beta-phase calcium pyrophosphate was evaluated by two exam iners in a double blind clinical caries study. T h e participants were 6 9 4 schoolchildren, aged 5 to 15 years, in subur ban Colum bus, Ohio. A fter 21 m onths, both exam iners observed statistically significant re ductions o f caries rates in the group using the fluoride dentifrice.
Doctors Weisenstein and Zacherl are research associates at th e College o f Dentistry, The Ohio State University, 305 W 12th Ave, Columbus, Ohio 43210.
1. Shaw, J.H. Fluoridation as a p u b lic health measure. Washington, DC, American Association fo r th e Advancement of Science, 1954, p 158. 2. Muhler, J.C., and others. Comparison between th e anticariogenic effects o f d e n tifrice s co n taining stannous flu o ride and sodium fluoride. JADA 51:556 Nov 1955. 3. Zacherl, W.A. A c lin ic a l evaluation o f sodium flu o rid e and stannous flu o rid e dentifrices. Abstracted, IADR Pro gram and Abstracts, No. 253, March 1968. 4. Reed, M.W., and King, J.D. A clin ic a l evaluation of'-a sodium flu o rid e den tifrice . Abstracted, IADR Program and Abstracts, No. 340, March 1970. 5. Green, G.E., and Weisenstein, P.R. Caries diagnosis and experim ental caries conference, fin a l report, 1960. (Re search foundation p ro je ct 977, National In s titu te s o f Health Grant D-1091) Columbus, Ohio, The Ohio State U niversity Research Foundation, 1960. Mimeographed. 6. Dubey, S.D.; Lehnhoff, R.W.; and Radike, A.W. A statistical confidence interval for tru e percent reduction in caries-incidence studies. J Dent Res 44:921 Sept-Oct 1965.
W eisenstein— Zacherl: EVALUATION OF SODI UM FLUORIDE DENTIFRICE ■ 623
P. R. Weisenstein, DDS W. A. Zacherl, DDS, MPh, Columbus, Ohio
Either a nontherapeutic d entifrice or a dentifrice containing sodium fluoride was assigned random ly to about 700 suburban schoolchildren for use. The children were examined at the beginning of the study, and then after 9, 16, and 21 months. After 21 months, the two examiners fo un d-sta tis tic a lly significant reductions o f caries in children using the fluoride dentifrice.
D ental researchers have been interested in sodium fluoride as an anticaries agent sin ce the early 1940s. A lthough early clinical studies o f den ti frice system s containing sodium fluoride failed to dem onstrate anticaries effectiven ess,1-2 a latent interest in sodium fluoride dentifrice system s persisted. With the advent o f an effective stan n ous fluoride dentifrice in the m id -1 9 5 0 s and with the ensuing advances in dentifrice techn ol ogy, new dentifrice system s containing sodium fluoride w ere pursued. In 1968, Zacherl3 reported a statistically significant reduction in dental caries with a neutral-pH sodium fluoride dentifrice sy s tem incorporating a new high-beta-phase calcium
pyrophosphate abrasive that is less soluble than ordinary dentifrice abrasives. R eed and King4 in 1970 also reported a statistically significant r e duction in dental caries for the sam e dentifrice system. T h is dentifrice system is the subject o f the clinical evaluation described in this report.
Procedure In this study, 694 children ranging in age from 5 to 15 years were recruited from several elem en tary schools in suburban C olum bus, O hio. F lu o r id e in the com m unal water supply was negligible. T h e children were accepted into the study on a voluntary basis with written consent o f th e parent or guardian. E xam inations o f each ch ild were conducted independently by both authors initially, then after 9 m onths, after 16 m onths, and at the term ination o f th e study after 21 m onths. A supervised brush ing with a nontherapeutic dentifrice preceded the exam inations at each stage o f the study. Both exam iners used a visual-tactile exam ination that was supplem ented by a seven-film bitew ing radiographic series for each child. D M F T (decayed, m issing and filled teeth) and D M F S (decayed, m issing, and filled surfaces) scores were recorded. G enerally recognized criteria for diagnosis o f carious lesion s5 w ere applied by both exam iners. E xam inations were conducted in th e schools with use o f p ortable field equipm ent. JADA, Vol. 84, March 1972 ■ 621
o f a nonstudy dentifrice w as m inim ized because enough dentifrice was given each ch ild to supply th e h ousehold for the duration o f th e study. I f m ore than o n e ch ild in a fam ily p articipated in the study, they w ere assigned the sam e dentifrice.
T h e findings o f o n e o f th e tw o exam iners were used arbitrarily for dentifrice assignm ent. Im m ediately after th e initial visual-tactile exam i nation, each ch ild was assigned on e o f the tw o dentifrices random ly within the strata o f age, sex, and th e visual-tactile D M F S exam ination results. A lthough this clinical evaluation is based on findings in perm anent dentitions, th e findings on deciduous teeth were used in assigning den ti frices to kindergarten children. T h e control and test dentifrices w ere sim ilar in color, flavor, and other properties. T h e form ulations o f the den ti frices are given in T ab le 1. T h e exam iners had no know ledge o f th e den ti frice assigned to each child, and the children had no know ledge o f the identities o f th e dentifrices assigned to them. A ll clinical exam inations and radiographic interpretations w ere m ad e in d e pendently o f previous exam ination records. F rac tured teeth, banded teeth, and teeth extracted for orthodontic reasons w ere not included in the data tabulations. Posterior teeth that w ere e x tracted because o f caries w ere counted as three surfaces and extracted anterior teeth as two sur faces. H ow ever, a lesser num ber o f surfaces than that which w as counted on a previous exam ina tion was never recorded. T oothbrushes and a supply o f th e assigned d en tifrice in co d ed w hite tubes were given each ch ild p eriodically during the study. T h e p ossib le effect
Results and discussion T ab le 2 shows the initial characteristics o f the children who participated during th e various stages o f the study. A ge, D M F T , and D M F S are given as m eans. D esp ite the attrition in the n u m ber o f children, th e tw o dentifrice grou p s c o m p ared favorably throughout th e study. T h e tw o dentifrice groups show n o significant differences in th e initial characteristics for either exam iner at any stage. M ost o f th e ch il dr a t w ho d id not c o m p lete the study had m oved. A sm all num ber w ere absent on th e days o f exam ination. T ab les 3 and 4 show the m ean caries in cre m ents based on the D M F T and D M F S in dexes respectively for both exam iners after th e three stages o f the study. T h e results in term s o f percent reduction are consistent for each exam iner with th e exception o f the nine-m onth v a lu es for E xam iner B. T h e aberrant reductions are attributed to the circum stances under which the nine-m onth exam inations were made. D uring this period, Exam iner B w as in poor health and yet p articipated in th e exam inations because o f th e critical sched u le n ecessitated by a m ultiple-exam iner study. T h e probabilities given are based on a o n e tailed norm al deviate test.6 Exam iner A observed statistically significant ( « = 0 .0 5 ) caries reductions, based on the D M F T index after 16 and 21 m onths with use o f the fluoride dentifrice. E xam iner B found statistically significant caries reduction for th e fluoride dentifrice after 9, 16, and 21 m onths, based on both the D M F T and D M F S indexes.
Table 1 ■ D e n tifric e fo rm u la tio n s. % com position Com ponents
C ontrol den tifrice
Test den tifrice
40.00 1.48 1.38 24.00 33.14
40.00 1.48 1.38 24.00 32.92
Sodium fluoride High-beta-phase calcium pyrophosphate Binders Surfactants Humectants Water, buffers, and flavor
0 22
Ta ble 2 ■ C h a ra c te ris tic s o f c h ild re n c o m p le tin g an in d ica te d p o rtio n o f th e study. Sex No. Stage C hildren starting test Children com pleting 9 m onths Children com pleting 16 months Children com pleting 21 m onths
Male
Age (yrs)
Female
Average
Range
D entifrice C ontrol N eutral-pH NaF C ontrol Neutral-pH NaF C ontrol Neutral-pH NaF C ontrol N eutral-pH NaF
DM FT Exam iner A
DMFS Exam iner B
E xam iner A
Exam iner B
Average
SE M '
Average
SEM
Average
SEM
Average
SEM
348 346 278 270
168 169 141 133
180 177 137 137
9.49 9.39 9.68 9.34
5-15 5-14 5-15 5-14
4.18 4.02 4.35 3.99
0.197 0.204 0.214 0.227
6.24 6.04 6.33 5.94
0.245 0.258 0.264 0 287
6.99 7.01 7.13 6.93
0.357 0.387 0.378 0.430
12.16 11.80 12.28 11.73
0.518 0.552 0.551 0.621
231 234
119 123
112 111
9.68 9.34
5-15 5-14
4.19 4.00
0.220 0.245
6.25 5.85
0.270 0.302
6.81 6.88
0.399 0.454
11.94 11.48
0.546 0.641
196 206
101 95
95 111
9.52 9.38
5-15 5-14
4.09 4.11
0.243 0.263
6.22 5.94
0.310 0.316
6.66 6.97
0.428 0.481
11.78 11.67
0.626 0.677
*SEM: standard erro r o f the mean.
622 ■ JADA, Vol. 84, March 1972
Table 3 ■ D M FT results d u rin g a 2 1 -m o n th p e rio d fo r all ch ild re n w h o co m p le te d th e sp e c ifie d stage o f th e stu d y. Exam iner A Stage
D entifrice
No.
AD M FT*
SEM t
Examiner B
P ro b t
% Reduction
ADMFT
SEM
Prob
% R eduction
0.125 1.19 0.81 0.106 C hildren C ontrol 278 77.8% 1.07 0.2090 0.18 0.090 <0.0001 0.102 10.1% com pleting Neutral-pH 270 NaF 9 m onths 0.174 2.01 1.93 0.129 C hildren 231 C ontrol 0.141 28.0% 1.56 0.127 0.0066 22.4% 1.39 0.0080 234 com pleting Neutral-pH 16 m onths NaF 2.60 0.208 3 40 0.198 C hildren 196 Control 0.0250 1.64 0.165 <0.0001 36.9% 2.90 0.161 14.7% com pleting NeutraJ-pH 206 21 m onths_________NaF__________________________________________________________________________________________________________________ _______ 'A D M F T is the mean increm ent fo r the DM FT index. fSEM is standard erro r of the mean. tP ro b is the probability that a difference as large as or larger than the observed difference between means co u ld have occurred by chance alone.
Table 4 ■ DMFS results during a 21-month period for all children who completed the specified stage o f the study. Examiner A Stage C hildren com pleting 9 m onths C hildren com pleting 16 months C hildren com pleting 21 months
Examiner B
Dentifrice
No.
AD M F S
SEMf
P ro b t
% reduction
AD M F S
SEM
Prob
C ontrol N eutral-pH NaF Control Neutral-pH NaF Control Neutral-pH NaF
278 270
1.96 1.75
0.177 0.166
0.1949
10.7%
1.05 -0.17
0.220 0.181
<0.0001
116.2%
231 234
3.16 2.75
0.204 0.197
13.0%
4.02 2.78
0.348 0.273
0.0026
30.8%
196 206
5.60 4.98
0.310 0.279
11.1%
4.76 2.94
0.407 0.324
<0.0002
38.2%
0.0735
0.0681
% reductio
*AD M FS is the mean increm ent fo r the DMFS index. tS E M is standard error of the mean. {P ro b is the probab ility that a difference as large as o r la rge r than the observed difference between means c o u ld have occurred by chance alone.
Summary and conclusions A neutral-pH dentifrice containing sodium flour id e and high-beta-phase calcium pyrophosphate was evaluated by two exam iners in a double blind clinical caries study. T h e participants were 6 9 4 schoolchildren, aged 5 to 15 years, in subur ban Colum bus, Ohio. A fter 21 m onths, both exam iners observed statistically significant re ductions o f caries rates in the group using the fluoride dentifrice.
Doctors Weisenstein and Zacherl are research associates at th e College o f Dentistry, The Ohio State University, 305 W 12th Ave, Columbus, Ohio 43210.
1. Shaw, J.H. Fluoridation as a p u b lic health measure. Washington, DC, American Association fo r th e Advancement of Science, 1954, p 158. 2. Muhler, J.C., and others. Comparison between th e anticariogenic effects o f d e n tifrice s co n taining stannous flu o ride and sodium fluoride. JADA 51:556 Nov 1955. 3. Zacherl, W.A. A c lin ic a l evaluation o f sodium flu o rid e and stannous flu o rid e dentifrices. Abstracted, IADR Pro gram and Abstracts, No. 253, March 1968. 4. Reed, M.W., and King, J.D. A clin ic a l evaluation of'-a sodium flu o rid e den tifrice . Abstracted, IADR Program and Abstracts, No. 340, March 1970. 5. Green, G.E., and Weisenstein, P.R. Caries diagnosis and experim ental caries conference, fin a l report, 1960. (Re search foundation p ro je ct 977, National In s titu te s o f Health Grant D-1091) Columbus, Ohio, The Ohio State U niversity Research Foundation, 1960. Mimeographed. 6. Dubey, S.D.; Lehnhoff, R.W.; and Radike, A.W. A statistical confidence interval for tru e percent reduction in caries-incidence studies. J Dent Res 44:921 Sept-Oct 1965.
W eisenstein— Zacherl: EVALUATION OF SODI UM FLUORIDE DENTIFRICE ■ 623