PURPOSE: As a requirement of the Food & Drug Administration's final monograph on "Anticaries drug... more PURPOSE: As a requirement of the Food & Drug Administration's final monograph on "Anticaries drug products for over-the-counter human use", the toothpaste industry has been conducting animal caries tests on every fluoride-containing toothpaste introduced into the U.S. market since 1996. The practice of testing in animals, although required by law, is in stark conflict with the corporate policy of many U.S. and global toothpaste manufacturers, in which, if possible, alternatives to animal testing are utilized. A provision does exist within the regulation which allows the use of an alternative method to demonstrate efficacy. However, to take advantage of this provision, a petition must be submitted to the FDA and in this petition data demonstrating the alternative provides results of "equivalent accuracy" must be included. After many years of research, model development and model comparisons, we have identified one particular laboratory model that demonstrated excellent correlation with the currently accepted animal caries models. This model, known as the Featherstone pH cycling model, is discussed in this paper.METHODS: The Featherstone pH cycling model has been shown to produce results of equivalent accuracy to the animal caries model by: (1) demonstrating a clinically relevant fluoride dose response similar to that shown in the animal caries model (including 1100 ppm F, 250 ppm F and placebo); (2) demonstrating similar results to the animal caries model for clinically proven dentifrice formulations relative to positive and negative controls; (3) demonstrating discriminating ability in strong agreement with the animal caries model for differentiating between a dentifrice formulation with attenuated fluoride activity and a USP standard; and (4) providing a clinically relevant representation of the caries process, as demonstrated by orthodontic banding studies. In addition, the model sufficiently addresses both salivary and abrasive/anticalculus agent interference concerns.RESULTS: For more than 50 years, fluoride has been the first defense in the fight against dental caries. The clinical effectiveness of fluoride is well accepted and documented extensively in the literature. The mechanism through which fluoride provides its benefit is very straightforward and well understood. The proposed laboratory model effectively simulates the effect of the caries process and has been shown to demonstrate equivalent accuracy to animal caries. This indicates that there are strong scientific grounds for the use of this model as an alternative to the animal caries test. Based on the strength of the data and the correlations noted between the two models, we recommend that the scientific community and the toothpaste industry broadly accept the Featherstone laboratory pH cycling model as an appropriate alternative to animal testing, particularly for ionic fluoride based dentifrices.
PURPOSE: To determine the ability of QLF to assess the activity of white spots using visual exami... more PURPOSE: To determine the ability of QLF to assess the activity of white spots using visual examination (VE) as the gold standard.METHODS: Thirty-four specimens were prepared from extracted human permanent posterior teeth presenting natural white spots on the approximal surface. Fluorescence images were acquired at 1-second intervals for the first 10 seconds and every 5 seconds thereafter to 45 seconds. During image acquisition, specimens were dehydrated with compressed air. QLF variables of fluorescence loss (deltaF [%]), lesion size (S [mm2]), and deltaQ (deltaFxS [% x mm2]), were determined. Change in QLF variables per second (deltaQLF(D): deltaF(D), deltaS(D), deltaQ(D)) was determined using the following equation: (subsequent QLF-variables--baseline QLF-variables)/dehydration time. Five experienced dentists independently conducted VE under standardized conditions using a dental unit's light, compressed air, with an explorer, used only to check surface structure. Prior to VE, examiners had participated in a half-day training seminar on VE. After drying the specimens, examiners graded the lesions according to dullness of surface, roughness and presence of microcavitation. Agreement by at least three of them determined the activity status of lesions.RESULTS: deltaQLF(D) values of Active white spot group (n = 7) were compared with those of Inactive white spot group (n = 27) using a two-sample t-test. In general, the active group presented larger values of deltaQLF(D) than the inactive group; however, there were no differences in deltaF(D) and deltaS(D). There were significant differences in deltaQ(D) up to 6 seconds of dehydration (P < 0.05), and no differences after 7 seconds. The results suggest that deltaQ(D) can differentiate between active and inactive white spot lesions using QLF during the first few seconds of dehydration.
The chapter describes briefly the current methodologies used to measure mineral gain and loss in ... more The chapter describes briefly the current methodologies used to measure mineral gain and loss in dental enamel and dentin using confocal microscopy. The studies described in the chapter support the use of confocal laser scanning microscopy (CLSM) as an effective technique for measuring in vitro mineral changes in dental tissues. Enamel is more mineralized than bone or dentin. It is approximately 99% mineral by weight and averages 87% mineral by volume. Most of the research up to date has focused on the two-dimensional (2-D) analysis of affected areas, not taking into account the potential for optical sectioning of the teeth that CLSM offers. Studies have focused on the measurement of fluorescent dye penetration in the porosities of demineralized tissue, on the measurement of changes in autofluorescence of the tissue, or on the changes in the reflection of light from the lesion. Analyses have been done on intact surfaces and cross sections, with the latter being studied most frequently. Future studies need to focus on the three-dimensional (3-D) analysis of carious lesions, as new information could be gained by analyzing volume changes and mineral distributions.
This clinical investigation was conducted to evaluate the impact of a unique soft rawhide product... more This clinical investigation was conducted to evaluate the impact of a unique soft rawhide product on the formation of dental calculus in a housed colony of beagle dogs. The study was designed as a 2-way crossover test with 4-week test periods and a 1-week wash-out period between the test periods. All dogs were provided a dry commercial diet and tap water ad libitum. The dogs were stratified into two groups of matched pairs on the basis of their calculus and plaque formation rates. Each test period was initiated immediately following a complete supragingival scaling and crown polishing and the dogs in the test group received a soft rawhide treat about 4-hours after their normal feeding. Examinations were performed about 20 to 24-hours after the last feeding by an experienced clinical examiner using conventional indices. The data indicated that once daily feeding of the soft rawhide chew product resulted in statistically significant reductions in the formation of dental calculus (28.0%), dental plaque (19.0%), and gingivitis (46.0%).
Clinical and Diagnostic Laboratory Immunology, May 1, 1999
Streptococcus mutans has been identified as the major etiological agent of human dental caries. T... more Streptococcus mutans has been identified as the major etiological agent of human dental caries. The first step in the initiation of infection by this pathogenic bacterium is its attachment (i.e., through bacterial surface proteins such as glucosyltransferases, P1, glucan-binding proteins, and fimbriae) to a suitable receptor. It is hypothesized that a mucosal vaccine against a combination of S. mutans surface proteins would protect against dental caries by inducing specific salivary immunoglobulin A (IgA) antibodies which may reduce bacterial pathogenesis and adhesion to the tooth surface by affecting several adhesins simultaneously. Conventional Sprague-Dawley rats, infected with S. mutans at 18 to 20 days of age, were intranasally immunized with a mixture of
To compare the distribution of the three most suspected cariogenic groups of bacteria, mutans str... more To compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci, Actinomyces naeslundii genospecies 2, and lactobacilli in carious lesions around tooth-colored restorations. Samples from extracted teeth with clinical secondary caries around tooth-colored restorations were immuno-labeled with antibodies to the referred groups of bacteria and subsequently analyzed three dimensionally using confocal microscopy. The three different bacterial groups were usually present in secondary caries around tooth-colored restorations suggesting that they are involved in its formation and development.
Purpose: To assess the "whitening" through stain removal benefit delivered by a prototype power t... more Purpose: To assess the "whitening" through stain removal benefit delivered by a prototype power toothbrush and a positive control power toothbrush over a 2-week period. Methods: Four independent studies with identical protocols were conducted to examine tooth whitening through the removal of extrinsic stain with power toothbrushes. These were randomized, positive-controlled, two treatment, parallel group, examiner-blind, 2-week studies involving approximately 20 healthy adults with longstanding visible extrinsic stain on the facial surfaces of the 12 anterior teeth. Approximately 10 subjects per group were enrolled into the study for each of the two treatment groups; a prototype-powered toothbrush group (Crest SpinBrush Pro Whitening) and a positive control powered toothbrush group (Sonicare Personal 4100). Results: In these four studies, the positive control sonic power toothbrush statistically significantly (P< 0.05) reduced stain scores by 84%, 77%, 44% and 49% following 2 weeks of brushing. Importantly, the prototype whitening power toothbrush statistically significantly (P< 0.05) reduced stain scores by 88%, 65%,59% and 57% following 2 weeks of brushing. In both the individual studies and a combined analysis involving all four studies, the adjusted mean changes between treatment groups did not differ significantly between the two treatment groups. In the combined analysis, a one-sided upper 95% confidence bound on the difference in stain reduction scores between the two toothbrushes (positive control minus prototype) was found to be 8.3% of the prototype toothbrush adjusted mean change. This supports that the prototype power toothbrush removed extrinsic stain at least as well as the positive control toothbrush across these four studies. (Am J Dent 2004;17: 18A-24A).
Development of dental caries is associated with the loss of minerals and change in the enamel str... more Development of dental caries is associated with the loss of minerals and change in the enamel structure. In this study, we have measured and compared reflectance spectra of sound and carious enamel, to investigate its utility in detection and analysis of dental caries. One hundred twenty, 3-mm diameter human enamel cores, with no sign of fluorosis, tetracycline stain, hypoplasia, fracture
This study evaluated the agreement between clinical and photographic assessment of dental fluoros... more This study evaluated the agreement between clinical and photographic assessment of dental fluorosis (DF) in 73 children during a field study, using portable equipment and a standardising device. A dental exam was performed using the Tooth Surface Index of Fluorosis (TSIF). Photographs of the facial aspects of front teeth and from the occlusal aspect of the mandibular posterior teeth were taken. All photographs were taken following a standard operating procedure. Photographs of anterior and posterior teeth were coded and assigned a random study number. Examiners scored photographs as fluorosis cases or non-cases. Agreement among the clinical examiners ranged from good to excellent. Agreement was also good for the repeated photographic evaluations. In total, 22% of the children were diagnosed with DF during a clinical exam, and 19% were diagnosed with DF using the photographs. Development of this method aided in the photographic assessment of DF. The photographs obtained were a useful...
PURPOSE: As a requirement of the Food & Drug Administration's final monograph on "Anticaries drug... more PURPOSE: As a requirement of the Food & Drug Administration's final monograph on "Anticaries drug products for over-the-counter human use", the toothpaste industry has been conducting animal caries tests on every fluoride-containing toothpaste introduced into the U.S. market since 1996. The practice of testing in animals, although required by law, is in stark conflict with the corporate policy of many U.S. and global toothpaste manufacturers, in which, if possible, alternatives to animal testing are utilized. A provision does exist within the regulation which allows the use of an alternative method to demonstrate efficacy. However, to take advantage of this provision, a petition must be submitted to the FDA and in this petition data demonstrating the alternative provides results of "equivalent accuracy" must be included. After many years of research, model development and model comparisons, we have identified one particular laboratory model that demonstrated excellent correlation with the currently accepted animal caries models. This model, known as the Featherstone pH cycling model, is discussed in this paper.METHODS: The Featherstone pH cycling model has been shown to produce results of equivalent accuracy to the animal caries model by: (1) demonstrating a clinically relevant fluoride dose response similar to that shown in the animal caries model (including 1100 ppm F, 250 ppm F and placebo); (2) demonstrating similar results to the animal caries model for clinically proven dentifrice formulations relative to positive and negative controls; (3) demonstrating discriminating ability in strong agreement with the animal caries model for differentiating between a dentifrice formulation with attenuated fluoride activity and a USP standard; and (4) providing a clinically relevant representation of the caries process, as demonstrated by orthodontic banding studies. In addition, the model sufficiently addresses both salivary and abrasive/anticalculus agent interference concerns.RESULTS: For more than 50 years, fluoride has been the first defense in the fight against dental caries. The clinical effectiveness of fluoride is well accepted and documented extensively in the literature. The mechanism through which fluoride provides its benefit is very straightforward and well understood. The proposed laboratory model effectively simulates the effect of the caries process and has been shown to demonstrate equivalent accuracy to animal caries. This indicates that there are strong scientific grounds for the use of this model as an alternative to the animal caries test. Based on the strength of the data and the correlations noted between the two models, we recommend that the scientific community and the toothpaste industry broadly accept the Featherstone laboratory pH cycling model as an appropriate alternative to animal testing, particularly for ionic fluoride based dentifrices.
PURPOSE: To determine the ability of QLF to assess the activity of white spots using visual exami... more PURPOSE: To determine the ability of QLF to assess the activity of white spots using visual examination (VE) as the gold standard.METHODS: Thirty-four specimens were prepared from extracted human permanent posterior teeth presenting natural white spots on the approximal surface. Fluorescence images were acquired at 1-second intervals for the first 10 seconds and every 5 seconds thereafter to 45 seconds. During image acquisition, specimens were dehydrated with compressed air. QLF variables of fluorescence loss (deltaF [%]), lesion size (S [mm2]), and deltaQ (deltaFxS [% x mm2]), were determined. Change in QLF variables per second (deltaQLF(D): deltaF(D), deltaS(D), deltaQ(D)) was determined using the following equation: (subsequent QLF-variables--baseline QLF-variables)/dehydration time. Five experienced dentists independently conducted VE under standardized conditions using a dental unit's light, compressed air, with an explorer, used only to check surface structure. Prior to VE, examiners had participated in a half-day training seminar on VE. After drying the specimens, examiners graded the lesions according to dullness of surface, roughness and presence of microcavitation. Agreement by at least three of them determined the activity status of lesions.RESULTS: deltaQLF(D) values of Active white spot group (n = 7) were compared with those of Inactive white spot group (n = 27) using a two-sample t-test. In general, the active group presented larger values of deltaQLF(D) than the inactive group; however, there were no differences in deltaF(D) and deltaS(D). There were significant differences in deltaQ(D) up to 6 seconds of dehydration (P < 0.05), and no differences after 7 seconds. The results suggest that deltaQ(D) can differentiate between active and inactive white spot lesions using QLF during the first few seconds of dehydration.
The chapter describes briefly the current methodologies used to measure mineral gain and loss in ... more The chapter describes briefly the current methodologies used to measure mineral gain and loss in dental enamel and dentin using confocal microscopy. The studies described in the chapter support the use of confocal laser scanning microscopy (CLSM) as an effective technique for measuring in vitro mineral changes in dental tissues. Enamel is more mineralized than bone or dentin. It is approximately 99% mineral by weight and averages 87% mineral by volume. Most of the research up to date has focused on the two-dimensional (2-D) analysis of affected areas, not taking into account the potential for optical sectioning of the teeth that CLSM offers. Studies have focused on the measurement of fluorescent dye penetration in the porosities of demineralized tissue, on the measurement of changes in autofluorescence of the tissue, or on the changes in the reflection of light from the lesion. Analyses have been done on intact surfaces and cross sections, with the latter being studied most frequently. Future studies need to focus on the three-dimensional (3-D) analysis of carious lesions, as new information could be gained by analyzing volume changes and mineral distributions.
This clinical investigation was conducted to evaluate the impact of a unique soft rawhide product... more This clinical investigation was conducted to evaluate the impact of a unique soft rawhide product on the formation of dental calculus in a housed colony of beagle dogs. The study was designed as a 2-way crossover test with 4-week test periods and a 1-week wash-out period between the test periods. All dogs were provided a dry commercial diet and tap water ad libitum. The dogs were stratified into two groups of matched pairs on the basis of their calculus and plaque formation rates. Each test period was initiated immediately following a complete supragingival scaling and crown polishing and the dogs in the test group received a soft rawhide treat about 4-hours after their normal feeding. Examinations were performed about 20 to 24-hours after the last feeding by an experienced clinical examiner using conventional indices. The data indicated that once daily feeding of the soft rawhide chew product resulted in statistically significant reductions in the formation of dental calculus (28.0%), dental plaque (19.0%), and gingivitis (46.0%).
Clinical and Diagnostic Laboratory Immunology, May 1, 1999
Streptococcus mutans has been identified as the major etiological agent of human dental caries. T... more Streptococcus mutans has been identified as the major etiological agent of human dental caries. The first step in the initiation of infection by this pathogenic bacterium is its attachment (i.e., through bacterial surface proteins such as glucosyltransferases, P1, glucan-binding proteins, and fimbriae) to a suitable receptor. It is hypothesized that a mucosal vaccine against a combination of S. mutans surface proteins would protect against dental caries by inducing specific salivary immunoglobulin A (IgA) antibodies which may reduce bacterial pathogenesis and adhesion to the tooth surface by affecting several adhesins simultaneously. Conventional Sprague-Dawley rats, infected with S. mutans at 18 to 20 days of age, were intranasally immunized with a mixture of
To compare the distribution of the three most suspected cariogenic groups of bacteria, mutans str... more To compare the distribution of the three most suspected cariogenic groups of bacteria, mutans streptococci, Actinomyces naeslundii genospecies 2, and lactobacilli in carious lesions around tooth-colored restorations. Samples from extracted teeth with clinical secondary caries around tooth-colored restorations were immuno-labeled with antibodies to the referred groups of bacteria and subsequently analyzed three dimensionally using confocal microscopy. The three different bacterial groups were usually present in secondary caries around tooth-colored restorations suggesting that they are involved in its formation and development.
Purpose: To assess the "whitening" through stain removal benefit delivered by a prototype power t... more Purpose: To assess the "whitening" through stain removal benefit delivered by a prototype power toothbrush and a positive control power toothbrush over a 2-week period. Methods: Four independent studies with identical protocols were conducted to examine tooth whitening through the removal of extrinsic stain with power toothbrushes. These were randomized, positive-controlled, two treatment, parallel group, examiner-blind, 2-week studies involving approximately 20 healthy adults with longstanding visible extrinsic stain on the facial surfaces of the 12 anterior teeth. Approximately 10 subjects per group were enrolled into the study for each of the two treatment groups; a prototype-powered toothbrush group (Crest SpinBrush Pro Whitening) and a positive control powered toothbrush group (Sonicare Personal 4100). Results: In these four studies, the positive control sonic power toothbrush statistically significantly (P< 0.05) reduced stain scores by 84%, 77%, 44% and 49% following 2 weeks of brushing. Importantly, the prototype whitening power toothbrush statistically significantly (P< 0.05) reduced stain scores by 88%, 65%,59% and 57% following 2 weeks of brushing. In both the individual studies and a combined analysis involving all four studies, the adjusted mean changes between treatment groups did not differ significantly between the two treatment groups. In the combined analysis, a one-sided upper 95% confidence bound on the difference in stain reduction scores between the two toothbrushes (positive control minus prototype) was found to be 8.3% of the prototype toothbrush adjusted mean change. This supports that the prototype power toothbrush removed extrinsic stain at least as well as the positive control toothbrush across these four studies. (Am J Dent 2004;17: 18A-24A).
Development of dental caries is associated with the loss of minerals and change in the enamel str... more Development of dental caries is associated with the loss of minerals and change in the enamel structure. In this study, we have measured and compared reflectance spectra of sound and carious enamel, to investigate its utility in detection and analysis of dental caries. One hundred twenty, 3-mm diameter human enamel cores, with no sign of fluorosis, tetracycline stain, hypoplasia, fracture
This study evaluated the agreement between clinical and photographic assessment of dental fluoros... more This study evaluated the agreement between clinical and photographic assessment of dental fluorosis (DF) in 73 children during a field study, using portable equipment and a standardising device. A dental exam was performed using the Tooth Surface Index of Fluorosis (TSIF). Photographs of the facial aspects of front teeth and from the occlusal aspect of the mandibular posterior teeth were taken. All photographs were taken following a standard operating procedure. Photographs of anterior and posterior teeth were coded and assigned a random study number. Examiners scored photographs as fluorosis cases or non-cases. Agreement among the clinical examiners ranged from good to excellent. Agreement was also good for the repeated photographic evaluations. In total, 22% of the children were diagnosed with DF during a clinical exam, and 19% were diagnosed with DF using the photographs. Development of this method aided in the photographic assessment of DF. The photographs obtained were a useful...
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Papers by George Stookey