Effects of silver diamine fluoride on demineralization protection after a secondary acid challenge.

OBJECTIVE: This investigation describes the effects of 5% sodium fluoride varnish and 38% silver diamine fluoride on demineralization protection of human enamel lesions of three different severities after a secondary acid challenge. STUDY DESIGN: Specimens underwent color and enamel surface microhardness change measurements after demineralization and treatment events. Transverse microradiography was conducted following the secondary demineralization. RESULTS: After treatments, enamel surface microhardness change showed that 24-hour lesions treated with fluoride varnish had less rehardening than 24-hour lesions treated with silver diamine fluoride (p<0.05), whereas 144-hour lesions from both treatment groups showed a beneficial decrease in surface microhardness change that was markedly better in samples treated with silver diamine fluoride (p<0.05). After the secondary demineralization, 24- and 144-hour lesions treated with silver diamine fluoride showed a sustained beneficial decrease in enamel surface microhardness change when compared to fluoride varnish-treated samples of the corresponding lesion severity (p<0.05). Transverse microradiography showed no difference between fluoride varnish- and silver diamine fluoride-treated samples of any corresponding lesion severity, indicating that remineralization in both fluoride varnish- and silver diamine fluoride-treated samples was proportional to each other after a secondary acid challenge. CONCLUSIONS: Using silver diamine fluoride may have comparable benefits to fluoride varnish in mineral loss prevention.

Longitudinal assessment of dental erosion-abrasion by cross-polarization optical coherence tomography in vitro.

This study tested a novel in vitro dental erosion-abrasion model and the performance of cross-polarization optical coherence tomography (CP-OCT) in longitudinally monitoring the simulated lesions. Thirty human enamel specimens were prepared and randomized to receive three dental erosion-abrasion (EA) protocols: severe (s-EA, lemon juice/pH:2.5/4.25%w/v citric acid), moderate (m-EA, grapefruit juice/pH:3.5/1.03%w/v citric acid) and no-EA (water, control). EA challenge was performed by exposing the specimens to acidic solutions 4x/day and to brushing 2x/day with 1:3 fluoridated toothpaste slurry, for 14 days. Enamel thickness measurements were obtained using CP-OCT at baseline (D0), 7 (D7) and 14 days (D14) and micro-computed tomography (micro-CT) at D14. Enamel surface loss was measured with both CP-OCT and optical profilometry at D0, D7 and D14. Data was analyzed with repeated-measures ANOVA and Pearson's correlation (r) (α = 0.05). CP-OCT enamel thickness decreased over time in the s-EA group (D0 >D7 > D14, p < 0.001) and m-EA group (D0 > D14, p = 0.019) but did not change in the no-EA group (p = 0.30). Overall, CP-OCT and micro-CT results at D14 correlated moderately (r = 0.73). CP-OCT surface loss was highest for s-EA (p <0.001) but did not differ between moderate and no-EA (p = 0.25). Enamel surface loss with profilometry increased with severity (no-EA>m-EA>s-EA, p < 0.001). D14 surface loss was higher than D7 for both methods except for the no-EA group with profilometry. CP-OCT and profilometry had moderate overall correlation (r = 0.70). Our results revealed that the currently proposed in vitro dental erosion-abrasion model is valid and could simulate lesions of different severities over time. CP-OCT was a suitable method for monitoring the EA lesions.

Susceptibility of fluorotic enamel to dental erosion-abrasion.

Dental hard tissue conditions can be of pre- or post-eruptive nature, such as enamel fluorosis and erosive tooth wear (ETW), respectively. Dental enamel fluorosis is caused by the chronic and excessive intake of fluoride during enamel development, leading to increased fluoride concentration and increased porosity. ETW has become a common clinical condition and often impairs dental function and aesthetics. This in vitro study tested the hypothesis that fluorotic enamel presents different susceptibility to dental erosion-abrasion. It consisted of a 3×3×2 factorial design, considering a) fluorosis severity: sound (TF0), mild (TF1-2), moderate (TF3-4); b) abrasive challenge: low, medium, and high; and c) erosive challenge: yes or no. A total of 144 human teeth were selected according to the three fluorosis severity levels (n=48), and subdivided into six groups (n = 8) generated by the association of the different erosive and abrasive challenges. Enamel blocks (4×4 mm) were prepared from each tooth and their natural enamel surfaces subjected to an erosion-abrasion cycling model. After cycling, the depth of the lesions in enamel was assessed by profilometry. ANOVA showed that the three-way and two-way interactions among the factors were not significant (p > 0.20). Enamel fluorosis level (p=0.638) and abrasion level (p = 0.390) had no significant effect on lesion depth. Acid exposure caused significantly more enamel surface loss than water (p < 0.001). Considering the limitations of this in vitro study, fluorosis did not affect the susceptibility of enamel to dental erosion-abrasion.

Susceptibility of fluorotic enamel to dental erosion-abrasion

Abstract Dental hard tissue conditions can be of pre- or post-eruptive nature, such as enamel fluorosis and erosive tooth wear (ETW), respectively. Dental enamel fluorosis is caused by the chronic and excessive intake of fluoride during enamel development, leading to increased fluoride concentration and increased porosity. ETW has become a common clinical condition and often impairs dental function and aesthetics. This in vitro study tested the hypothesis that fluorotic enamel presents different susceptibility to dental erosion-abrasion. It consisted of a 3×3×2 factorial design, considering a) fluorosis severity: sound (TF0), mild (TF1-2), moderate (TF3-4); b) abrasive challenge: low, medium, and high; and c) erosive challenge: yes or no. A total of 144 human teeth were selected according to the three fluorosis severity levels (n=48), and subdivided into six groups (n = 8) generated by the association of the different erosive and abrasive challenges. Enamel blocks (4×4 mm) were prepared from each tooth and their natural enamel surfaces subjected to an erosion-abrasion cycling model. After cycling, the depth of the lesions in enamel was assessed by profilometry. ANOVA showed that the three-way and two-way interactions among the factors were not significant (p > 0.20). Enamel fluorosis level (p=0.638) and abrasion level (p = 0.390) had no significant effect on lesion depth. Acid exposure caused significantly more enamel surface loss than water (p < 0.001). Considering the limitations of this in vitro study, fluorosis did not affect the susceptibility of enamel to dental erosion-abrasion.

Longitudinal assessment of dental erosion-abrasion by cross-polarization optical coherence tomography in vitro

Abstract: This study tested a novel in vitro dental erosion-abrasion model and the performance of cross-polarization optical coherence tomography (CP-OCT) in longitudinally monitoring the simulated lesions. Thirty human enamel specimens were prepared and randomized to receive three dental erosion-abrasion (EA) protocols: severe (s-EA, lemon juice/pH:2.5/4.25%w/v citric acid), moderate (m-EA, grapefruit juice/pH:3.5/1.03%w/v citric acid) and no-EA (water, control). EA challenge was performed by exposing the specimens to acidic solutions 4x/day and to brushing 2x/day with 1:3 fluoridated toothpaste slurry, for 14 days. Enamel thickness measurements were obtained using CP-OCT at baseline (D0), 7 (D7) and 14 days (D14) and micro-computed tomography (micro-CT) at D14. Enamel surface loss was measured with both CP-OCT and optical profilometry at D0, D7 and D14. Data was analyzed with repeated-measures ANOVA and Pearson's correlation (r) (α = 0.05). CP-OCT enamel thickness decreased over time in the s-EA group (D0 >D7 > D14, p < 0.001) and m-EA group (D0 > D14, p = 0.019) but did not change in the no-EA group (p = 0.30). Overall, CP-OCT and micro-CT results at D14 correlated moderately (r = 0.73). CP-OCT surface loss was highest for s-EA (p <0.001) but did not differ between moderate and no-EA (p = 0.25). Enamel surface loss with profilometry increased with severity (no-EA>m-EA>s-EA, p < 0.001). D14 surface loss was higher than D7 for both methods except for the no-EA group with profilometry. CP-OCT and profilometry had moderate overall correlation (r = 0.70). Our results revealed that the currently proposed in vitro dental erosion-abrasion model is valid and could simulate lesions of different severities over time. CP-OCT was a suitable method for monitoring the EA lesions.

Effects of silver diamine fluoride on demineralization protection after a secondary acid challenge

Abstract Objective This investigation describes the effects of 5% sodium fluoride varnish and 38% silver diamine fluoride on demineralization protection of human enamel lesions of three different severities after a secondary acid challenge. Study design Specimens underwent color and enamel surface microhardness change measurements after demineralization and treatment events. Transverse microradiography was conducted following the secondary demineralization. Results After treatments, enamel surface microhardness change showed that 24-hour lesions treated with fluoride varnish had less rehardening than 24-hour lesions treated with silver diamine fluoride (p<0.05), whereas 144-hour lesions from both treatment groups showed a beneficial decrease in surface microhardness change that was markedly better in samples treated with silver diamine fluoride (p<0.05). After the secondary demineralization, 24- and 144-hour lesions treated with silver diamine fluoride showed a sustained beneficial decrease in enamel surface microhardness change when compared to fluoride varnish-treated samples of the corresponding lesion severity (p<0.05). Transverse microradiography showed no difference between fluoride varnish- and silver diamine fluoride-treated samples of any corresponding lesion severity, indicating that remineralization in both fluoride varnish- and silver diamine fluoride-treated samples was proportional to each other after a secondary acid challenge. Conclusions Using silver diamine fluoride may have comparable benefits to fluoride varnish in mineral loss prevention.

Objective assessment of simulated non-carious cervical lesion by tridimensional digital scanning.

OBJECTIVE: To explore the use of 3D intraoral scanner/image analysis for the detection and monitoring of simulated non-carious cervical lesions (NCCLs) in vitro. MATERIALS AND METHODS: A total of 288 NCCLs of different severities and simulated using a laboratorial model associating toothbrush stiffness (soft, medium, and hard) and toothpaste abrasivity (low, medium, high, and negative control) were analyzed. Dental impressions were taken from specimens before and after 35K and 65K brushing strokes, and then scanned with a CEREC Omnicam scanner. 3D models were analyzed for volumetric tooth loss. 3D optical profilometry was considered as the gold standard. Data were analyzed using ANOVA and Fisher's PLSD tests (alpha = 0.05), and agreement between methods by using intraclass correlation coefficient. RESULTS: Toothbrushes of hard and mid stiffness caused higher tooth loss than soft when associated with the highest abrasive, at 35K and 65K strokes (p < 0.001). Variation in slurry abrasivity led to differences in tooth loss (with control < low < medium < high, p < 0.0001) after both 35K and 65K strokes, regardless of the type of toothbrush used, except at 35K, wherein control = low (p = 0.55). 35K strokes caused less tooth loss than 65K for all abrasive slurries (p < 0.0001) except controls. The intraclass correlation coefficient for agreement between the test and gold standard methods was 0.85. CONCLUSIONS: Analysis of 3D images from intraoral scanner could detect and monitor NCCL progression, although this ability was limited on incipient lesions. Overall good agreement was found between the test method and optical profilometry. CLINICAL RELEVANCE: The suggested method may be applicable to detect and monitor NCCLs clinically.

Susceptibility of Dental Enamel of Different Ages to Caries-Like Lesion Development.

This study investigated the impact of estimated age, anatomical location, and the presence of wear facets on the susceptibility of enamel to develop caries-like lesions. Extracted human premolars (n = 261) had their age estimated between 10 and 93 years old, using established forensic methods. Specimens of enamel (4 × 4 mm) were prepared from the middle of the buccal surfaces, preserving the outer surface layer. The central area of the block (4 × 1 mm) was protected with nail polish and used as an internal control. The specimens were demineralized for 8 days (with 0.1 M acetic acid, 1.28 mM Ca, 0.74 mM Pi, and 0.03 µg F/mL, pH 5.0), to simulate caries-like lesion development. They were then scanned individually using microtomography, and digital 2D images were used to calculate the outcomes of integrated mineral concentration loss (ΔZ in µm/g/cm3) and lesion depth (LD in µm) at 3 locations, i.e., the cervical, middle, and occlusal thirds. The presence of natural surface wear facets was considered in the analysis. Data were evaluated using a linear mixed-effects models (α = 0.05). ΔZ increased significantly as a function of estimated tooth age at all 3 locations, and this increase was greater after the age of 30 years (p < 0.001), when a higher ΔZ was found in the occlusal third than in the middle and cervical thirds (p < 0.001). LD increased only in the occlusal third before the age of 30 years (p = 0.039) and this increase was significantly greater after 30 years at all 3 locations (p < 0.01), with no differences among them (p > 0.15). The presence of wear facets significantly increased ΔZ and LD (p < 0.001 for both). Overall, we concluded that the susceptibility of enamel to developing caries-like lesions increased with estimated dental age. This effect was more pronounced after the estimated age of 30 years and in the presence of natural tooth wear facets.

Blood levels of lead and dental caries in permanent teeth.

OBJECTIVES: The purpose of this study was to determine whether there is an association between lead exposure within the ages of 1-4 years and dental caries in the permanent dentition between ages 9-17 among Mexican youth. METHODS: Data were collected for the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort from a group of 490 children born and reared in Mexico City. Among ages 1-4 years, blood lead levels were measured in micrograms of lead per deciliter of blood (µg/dL) and the presence of caries in adolescence was determined using the International Caries and Detection and Assessment System (ICDAS). The relationship between blood levels of lead and decayed, missing, or filled surfaces (DMFS) was examined using negative binomial regression. Covariates were selected based on previous studies and included age, gender, socioeconomic status, oral hygiene, body mass index, and diet. The nonlinear relationship between lead and DMFS was examined using smoothing splines. RESULTS: The mean overall blood lead level (BLL) was 4.83 µg/dL (S.D. of 2.2). The mean overall caries level (DMFS) was 4.1. No statistically significant association was found between early childhood blood lead levels and dental caries in adolescence. CONCLUSION: This study shows a lack of association between exposure to lead between the ages of 1-4 years of age and dental caries in permanent dentition later in life. Other covariates, such as age and sugar consumption, appeared to play a more prominent role in caries development.

Cross-Sectional Association between Behaviors Related to Sugar-Containing Foods and Dental Outcomes among Hispanic Immigrants.

A cross-sectional, self-administered survey was used to gather information about dental outcomes, sugar-containing food behaviors and intake, and sociodemographic characteristics of adults of Mexican and Central-American (Guatemala, El Salvador, Honduras) origin (n = 517). Bivariate and multiple-variable logistic regressions were used to examine the associations of behaviors related to added sugar-containing foods/beverages (overall intake and consumption before bed) with dental outcomes. Outcome measures involved dental outcomes, dental self-care practices, and added sugar intake. Estimated daily added sugar intake among all participants was 98 (SD = 99) g, with no difference in consumption among participants from different countries. The majority of added sugar (63 (SD = 74) g) was provided by sugar-sweetened beverages. Participants who reported consuming sugar-containing foods or beverages within an hour before bed were more likely to report having a fair/poor/very poor condition of teeth and gums and having felt dental pain (p < 0.05 for all). The amount of sugar intake was associated with being prescribed medication for oral or dental problems (p = 0.008) and dental pain (p = 0.003). Findings support the association between sugar containing food-related behaviors and dental problems among Hispanic immigrants to the U.S. Health promotion and preventive interventions for this population should consider these behaviors as modifiable contributors to adverse dental outcomes.

Interplay between toothbrush stiffness and dentifrice abrasivity on the development of non-carious cervical lesions.

OBJECTIVE: This study investigated the effect of toothbrush stiffness and dentifrice slurry abrasivity on the development and progression of simulated non-carious cervical lesions (NCCLs). MATERIALS AND METHODS: Human maxillary premolars were allocated to 12 groups generated by the association between toothbrushes, soft, medium, and hard stiffness, and simulated dentifrice slurries, lower, medium, and higher; deionized water (DI) served as negative control. Teeth were mounted on acrylic blocks, and their root surfaces partially covered with acrylic resin to simulate gingiva, leaving a 2-mm area apical to the cemento-enamel junction exposed to toothbrushing. Specimens were brushed with the test slurries for 35,000 and 65,000 double strokes. Impressions taken at baseline and after both brushing periods were scanned by a 3D optical profilometer. Dentin volume loss (mm3) was calculated by image subtraction. Data were analyzed using three-way ANOVA and Fisher's PLSD tests. RESULTS: All toothbrushes caused higher volume loss when associated to higher abrasive slurry, compared to medium- and lower-abrasive slurries. Medium caused more volume loss than lower-abrasive slurry, which led to more volume loss than DI. Hard and medium toothbrushes were not different when used with medium- or higher-abrasive slurries. There were no differences among toothbrushes when used with DI and lower-abrasive slurry. Overall, 35,000 brushing strokes resulted in significantly less volume loss than 65,000. CONCLUSIONS: Toothbrush stiffness was an important factor on NCCL development, especially when brushing with medium- and higher-abrasive slurries. CLINICAL RELEVANCE: Medium and hard toothbrushes associated with medium- and high-abrasive toothpastes can yield more severe NCCLs.

Caries lesion remineralization with fluoride toothpastes and chlorhexidine - effects of application timing and toothpaste surfactant.

INTRODUCTION: Habitual toothbrushing with fluoridated toothpaste followed by rinsing with antibacterial mouthwashes is a method to maintain good oral hygiene and to diminish the occurrence and severity of dental caries and periodontal disease. However, our understanding of how antimicrobial agents in mouthwashes affect fluoride-mediated caries lesion remineralization is still poor. OBJECTIVE: The objectives of this in vitro study were a) to determine the effects of the waiting period of chlorhexidine (CHX) rinsing after fluoride toothpaste use and b) to further determine the effect of the type of toothpaste surfactant [sodium dodecyl sulfate (SDS) or cocamidopropyl betaine (CAPB)] on caries lesion remineralization associated with CHX rinsing. MATERIAL AND METHODS: Caries lesions were formed in bovine enamel specimens and assigned to 10 treatment groups (n=18) based on Vickers surface microhardness (VHN). Lesions were then pH-cycled for 10 days with daily regimen comprised of twice daily toothpaste slurry treatments (1150 ppm fluoride, with SDS or CAPB), followed by CHX solution treatments [0, 15, 30 or 60 minutes following slurry treatment or no CHX treatment (negative control)]. VHN was measured again and the extent of lesion remineralization calculated (∆VHN). RESULTS: ∆VHN with SDS-toothpaste was significantly lower than with CAPB-toothpaste, indicating more remineralization for the CAPB-toothpaste. ∆VHN with 0-minute waiting time was significantly lower than with 30-minute waiting time and with negative control. CONCLUSIONS: The absence of CHX as an adjunct to fluoride toothpastes led to greater remineralization of enamel lesions compared with the immediate use of CHX treatment for both SDS- and CAPB-toothpastes. CAPB-toothpastes indicated significantly greater remineralization than SDS-toothpastes, and can be suggested for patients at high risk of caries. A 30-minute waiting time for CHX treatment is recommended after brushing.

Factors associated with seeking preventive dental care: an integrative model exploration of behaviors in Mexican immigrants in Midwest America.

BACKGROUND: Mexican immigrants in the United States suffer from poor oral health. The objective of the current study was to explore the utility of applying theory-based factors associated with seeking preventive dental care in a sample of Mexican American adults. METHODS: Data were collected from a cross-sectional survey of a sample of 157 people of Mexican origin (64% female; age 34 ± 11 years) recruited primarily from church congregations and lay community organizations in Central Indiana. Using the Integrative Model of Behavioral Prediction as the guiding framework, structural equation modeling was used to test factors associated with intention to seek preventive dental care. RESULTS: Attitude towards seeking preventive dental care (estimate = 0.37; p < .0001) and self-efficacy for seeking preventive dental care (estimate = 0.68; p < .0001) were associated with intention to seek preventive dental care. The association between dental beliefs and intention to seek preventive dental care was mediated by attitude and self-efficacy (indirect effect = 0.26, p = .002), and the association between past behavior and intention to seek preventive dental care was mediated by self-efficacy (indirect effect = 0.26, p = .003). CONCLUSIONS: These findings suggest that interventions to increase preventive dental care seeking behavior among Mexican Americans should focus on changing attitudes toward seeking preventive dental care and on increasing self-efficacy to seek preventive dental care. Findings also support the use of interventions to influence dental beliefs.

Caries lesion remineralization with fluoride toothpastes and chlorhexidine - effects of application timing and toothpaste surfactant

Abstract Habitual toothbrushing with fluoridated toothpaste followed by rinsing with antibacterial mouthwashes is a method to maintain good oral hygiene and to diminish the occurrence and severity of dental caries and periodontal disease. However, our understanding of how antimicrobial agents in mouthwashes affect fluoride-mediated caries lesion remineralization is still poor. Objective: The objectives of this in vitro study were a) to determine the effects of the waiting period of chlorhexidine (CHX) rinsing after fluoride toothpaste use and b) to further determine the effect of the type of toothpaste surfactant [sodium dodecyl sulfate (SDS) or cocamidopropyl betaine (CAPB)] on caries lesion remineralization associated with CHX rinsing. Material and Methods: Caries lesions were formed in bovine enamel specimens and assigned to 10 treatment groups (n=18) based on Vickers surface microhardness (VHN). Lesions were then pH-cycled for 10 days with daily regimen comprised of twice daily toothpaste slurry treatments (1150 ppm fluoride, with SDS or CAPB), followed by CHX solution treatments [0, 15, 30 or 60 minutes following slurry treatment or no CHX treatment (negative control)]. VHN was measured again and the extent of lesion remineralization calculated (∆VHN). Results: ∆VHN with SDS-toothpaste was significantly lower than with CAPB-toothpaste, indicating more remineralization for the CAPB-toothpaste. ∆VHN with 0-minute waiting time was significantly lower than with 30-minute waiting time and with negative control. Conclusions: The absence of CHX as an adjunct to fluoride toothpastes led to greater remineralization of enamel lesions compared with the immediate use of CHX treatment for both SDS- and CAPB-toothpastes. CAPB-toothpastes indicated significantly greater remineralization than SDS-toothpastes, and can be suggested for patients at high risk of caries. A 30-minute waiting time for CHX treatment is recommended after brushing.

Community-based assessment and intervention for early childhood caries in rural El Salvador.

OBJECTIVE: The objectives were to assess early childhood caries (ECC) in rural areas of El Salvador and to investigate the changes in caries and mouth pain in the presence of community-based interventions. METHODS: This study was a retrospective analysis of de-identified and anonymous data obtained from baseline and four annual follow-up visits that focused on the preventive oral health intervention and nutrition in a convenience sample of children 0-6 years of age. The decayed, missing and filled teeth (dmft) index for primary teeth was used as the survey tool. Caries was defined as a cavitated lesion. Descriptive statistics were used to describe the prevalence of ECC in the sample in relation to age and dmft score. Linear mixed model analysis of variance (ANOVA) and generalised linear mixed effects models were used to compare the pre-intervention and post-intervention outcomes. RESULTS: The prevalence of caries was 58%. Incorporation of a community oral health education and fluoride supplementation programme contributed to significant reductions in caries experience (from 74% to 61%) and mouth pain (from 58% to 39%), in children 3-6 years of age. CONCLUSIONS: ECC is a common public health problem in rural El Salvador. In an established community-based maternal-child health programme in El Salvador, there appears to be an association between the incorporation of preventive oral health intervention and improvement in children's oral health and quality of life over time.

Caries Detection around Restorations Using ICDAS and Optical Devices.

PURPOSE: Secondary caries is the major reason for replacement of restorations in operative dentistry. New detection methods and technology have the potential to improve the accuracy for diagnosis of secondary carious lesions. This in vitro study evaluated the performance of the ICDAS (International Caries Detection and Assessment System) visual criteria and optical devices for detecting secondary caries around amalgam and composite resin restorations in permanent teeth. MATERIALS AND METHODS: A total of 180 extracted teeth with Class I amalgam (N = 90) and resin composite (N = 90) restorations were selected. Two examiners analyzed the teeth twice using the visual criteria (ICDAS), laser fluorescence (LF), light-emitting diode device (MID), quantitative light-induced fluorescence system (QLF), and a prototype system based on the Fluorescence Enamel Imaging technique (Professional Caries Detection System, PCDS). The gold standard was determined by means of confocal laser scanning microscopy. RESULTS: High-reproducibility values were shown for all methods, except for MID in the amalgam group. For both groups the QLF and PCDS were the most sensitive methods, whereas the other methods presented better specificity (p < 0.05). CONCLUSION: All methods, except the MID device appeared to be potential methods for detecting secondary caries only around resin composite restorations, whereas around amalgam restorations all methods seemed to be questionable. CLINICAL SIGNIFICANCE: Using Internal Caries Detection and Assessment System (ICDAS), an LF device, quantitative light-induced fluorescence and a novel method based on Fluorescence Enamel Imaging technique may be effective for evaluating secondary caries around composite resin restorations.

Influence of Toothbrushing on the Antierosive Effect of Film-Forming Agents.

This study evaluated the influence of toothbrushing on the antierosive effect of solutions containing sodium fluoride (225 ppm/F), stannous chloride (800 ppm/Sn), sodium linear polyphosphate (2%/LPP), and their combinations, and deionized water as negative control (C). Solutions were tested in a 5-day erosion-remineralization-abrasion cycling model, using enamel and dentin specimens (n = 8). Erosion was performed 6 times/day for 5 min, exposure to the test solutions 3 times/day for 2min, and toothbrushing (or not) with toothpaste slurry 2 times/day for 2 min (45 strokes). Surface loss (SL) was determined by noncontact profilometry. Data were analyzed using three-way ANOVA (α = 0.05). Brushing caused more SL than no brushing for enamel (mean ± SD, in micrometers: 52.7 ± 6.6 and 33.0 ± 4.5, respectively), but not for dentin (28.2 ± 1.9 and 26.6 ± 1.8, respectively). For enamel without brushing, F+LPP+Sn showed the lowest SL (23.8 ± 3.4), followed by F+Sn (30.6 ± 4.9) and F+LPP (31.7 ± 1.7), which did not differ from each other. No differences were found between the other groups and C (37.8 ± 2.1). When brushing, F+LPP+Sn exhibited the lowest SL (36.7 ± 2.4), not differing from F+LPP (39.1 ± 1.8). F, F+Sn and LPP+Sn were similar (46.7 ± 2.9, 42.1 ± 2.8 and 45.3 ± 4.6, respectively) and better than C (52.7 ± 4.3). Sn (55.0 ± 2.4) and LPP (51.0 ± 4.3) did not differ from C. For dentin, neither groups differed from C, regardless of brushing. In conclusion, toothbrushing did not affect the antierosive effect of F+Sn, F+LPP and F+LPP+Sn on enamel, although overall it led to more erosion than nonbrushing. F and LPP+Sn showed a protective effect only under brushing conditions, whereas Sn and LPP did not exhibit any protection. For dentin, neither toothbrushing nor the test solutions influenced the development of erosion.

Enamel Carious Lesion Development in Response to Sucrose and Fluoride Concentrations and to Time of Biofilm Formation: An Artificial-Mouth Study.

The aim of this study was to evaluate both sucrose and fluoride concentrations and time of biofilm formation on enamel carious lesions induced by an in vitro artificial-mouth caries model. For Study 1, biofilms formed by streptococci and lactobacilli were grown on the surface of human enamel slabs and exposed to artificial saliva containing 0.50 or 0.75 ppmF (22.5 h/d) and broth containing 3 or 5% sucrose (30 min; 3x/d) over 5 d. In Study 2, biofilms were grown in the presence of 0.75 ppmF and 3% sucrose over 3 and 9 days. Counts of viable cells on biofilms, lesion depth (LD), and the integrated mineral loss (IML) on enamel specimens were assessed at the end of the tested conditions. Counts of total viable cells and L. casei were affected by sucrose and fluoride concentrations as well as by time of biofilm formation. Enamel carious lesions were shallower and IML was lower in the presence of 0.75 ppmF than in the presence of 0.50 ppmF (P < 0.005). No significant effect of sucrose concentrations was found with respect to LD and IML (P > 0.25). Additionally, deeper lesions and higher IML were found after 9 d of biofilm formation (P < 0.005). Distinct sucrose concentrations did not affect enamel carious lesion development. The severity of enamel demineralization was reduced by the presence of the higher fluoride concentration. Additionally, an increase in the time of biofilm formation produced greater demineralization. Our results also suggest that the present model is suitable for studying aspects related to caries lesion development.

Adiposity has unique influence on the renin-aldosterone axis and blood pressure in black children.

OBJECTIVE: To comparatively examine the effects of adiposity on the levels of plasma renin activity (PRA), plasma aldosterone concentration (PAC), and aldosterone-renin ratio (ARR) in young black and white children. STUDY DESIGN: We prospectively assessed 248 black and 345 white children and adolescents. A novel analytical technique was used to assess the concurrent influences of age and body mass index (BMI) on PRA, PAC, and ARR. The estimated effects were depicted by colored contour plots. RESULTS: In contrast to whites, blacks had lower PRA (2.76 vs 3.36 ng/mL/h; P < .001) and lower PAC (9.01 vs 14.59 ng/dL; P < .001). In blacks, BMI was negatively associated with PRA (P = .001), consistent with an association with a more expanded plasma volume; there was no association with PAC. In whites, BMI was positively associated with PAC (P = .005); we did not detect a BMI-PRA association. The effects of BMI on ARR were directionally similar in the two race groups but more pronounced in blacks. Mean systolic blood pressure was greater in blacks with lower PRA (P < .01), higher PAC (P = .015), and higher ARR (P = .49). CONCLUSIONS: An increase in adiposity was associated with a suppressed PRA in blacks and an increase in PAC in whites. The unique relationship between adiposity and renin-aldosterone axis in blacks suggests the possible existence of a population-specific mechanism characterized by volume expansion, which could in turn enhance the influences of adiposity on blood pressure in black children and adolescents.

In vitro evaluation of ICDAS and radiographic examination of occlusal surfaces and their association with treatment decisions.

This in vitro study evaluated the performance of visual (International Caries Detection and Assessment System [ICDAS]) and radiographic (bitewing [BW]) examinations for occlusal caries detection and their associations with treatment decision (TD). Permanent teeth (n=104) with occlusal surfaces varying from sound to cavitated were selected. Sites were identified from 10× occlusal surface photographs. Standardized bitewing (BW) radiographs were taken. Four dentists with at least five years of experience scored all teeth twice (one-week interval) for ICDAS (0­6), BW (0=sound, 1=caries restricted to enamel, 2=caries in outer third dentin, 3=caries in inner third dentin), and TD (0=no treatment, 1=sealant, 2=microabrasion and sealant, 3=round bur sealant, 4a=resin, 4b=amalgam). Histological validation was performed by observation under a light microscope, with lesions classified on a five-point scale. Intraexaminer and interexaminer repeatability were assessed using two-way tables and intraclass correlation coefficients (ICCs). Comparisons between percentage correct, specificity, sensitivity, and area under the receiver-operating characteristic (ROC) curve were performed using bootstrap analyses. ICCs for intraexaminer and interexaminer repeatability indicated good repeatability for each examiner, ranging from 0.78 to 0.88, and among examiners, ranging from 0.74 to 0.81. Correlation between ICDAS and TD was 0.85 and between BW and TD was 0.78. Correlation between the methods and histological scores was moderate (0.63 for ICDAS and 0.61 for BW). The area under the ROC curve was significantly greater for ICDAS than for BW (p<0.0001). ICDAS had significantly lower specificity than BW did (p=0.0269, 79% vs 94%); however, sensitivity was much higher for ICDAS than for BW (p<0.0001, 83% vs 44%). Data from this investigation suggested that the visual examination (ICDAS) showed better performance than radiographic examination for occlusal caries detection. The ICDAS was strongly associated with TD. Although the correlation between the ICDAS and BW was lower, it is still valuable in the clinical decision-making process.