scholarly journals Effect of Enamel Caries Lesion Baseline Severity on Fluoride Dose-Response

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Frank Lippert
Keyword(s):  
Dose Response ◽  
Artificial Saliva ◽  
Fluoride Concentration ◽  
Caries Lesion ◽  
Treatment Groups ◽  
Baseline Severity ◽  
Enamel Caries ◽  
Human Enamel ◽  
Ph Cycling ◽  
Early Caries

This study aimed to investigate the effect of enamel caries lesion baseline severity on fluoride dose-response under pH cycling conditions. Early caries lesions were created in human enamel specimens at four different severities (8, 16, 24, and 36 h). Lesions were allocated to treatment groups (0, 83, and 367 ppm fluoride as sodium fluoride) based on Vickers surface microhardness (VHN) and pH cycled for 5 d. The cycling model comprised 3 × 1 min fluoride treatments sandwiched between 2 × 60 min demineralization challenges with specimens stored in artificial saliva in between. VHN was measured again and changes versus lesion baseline were calculated (ΔVHN). Data were analyzed using two-way ANOVA (p<0.05). Increased demineralization times led to increased surface softening. The lesion severity×fluoride concentration interaction was significant (p<0.001). Fluoride dose-response was observed in all groups. Lesions initially demineralized for 16 and 8 h showed similar overall rehardening (ΔVHN) and more than 24 and 36 h lesions, which were similar. The 8 h lesions showed the greatest fluoride response differential (367 versus 0 ppm F) which diminished with increasing lesion baseline severity. The extent of rehardening as a result of the 0 ppm F treatment increased with increasing lesion baseline severity, whereas it decreased for the fluoride treatments. In conclusion, lesion baseline severity impacts the extent of the fluoride dose-response.

scholarly journals Effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness

2005 ◽  
Vol 16 (2) ◽  
pp. 103-106 ◽  
Author(s):  
Rogério de Oliveira ◽  
Adriana Franco Paes Leme ◽  
Marcelo Giannini
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Enamel Surface ◽  
Control Group ◽  
Carbamide Peroxide ◽  
Surface Microhardness ◽  
Treatment Groups ◽  
Peroxide Bleaching ◽  
Human Enamel

This in vitro study evaluated the surface microhardness of human enamel submitted to bleaching with 10% carbamide peroxide (CP) containing calcium or fluoride. Ninety-eight dental blocks (5 x 5 mm²) with polished enamel surfaces were randomly assigned to 7 treatment groups (n=14), as follows: without bleaching and storage in artificial saliva (control); 10% CP; 10% CP + 0.05% calcium; 10% CP + 0.1% calcium; 10% CP + 0.2% calcium; 10% CP + 0.2% fluoride; and 10% CP + 0.5% fluoride. During 14 days, enamel surfaces were daily exposed to a 6-h bleaching regimen followed by storage in artificial saliva. Surface microhardness was measured before (baseline), during (7th day), immediately after bleaching (14th day) and 1 week post bleaching. Data were analyzed by two-way ANOVA and Tukey's test (p<0.05). All treatments reduced SM significantly during the bleaching cycle (7th day), immediately after bleaching (14th day) and 1 week post bleaching, compared to baseline and to the unbleached control group. In conclusion, in spite of the addition of calcium and fluoride, all bleaching treatments affected the enamel surface microhardness.

scholarly journals An In Vitro Investigation of Anticaries Efficacy of Fluoride Varnishes

2019 ◽  
Vol 44 (5) ◽  
pp. E234-E243 ◽  
Author(s):  
L Al Dehailan ◽  
EA Martinez-Mier ◽  
GJ Eckert ◽  
F Lippert
Keyword(s):  
Artificial Saliva ◽  
Acid Resistance ◽  
Fluoride Release ◽  
In Vitro Investigation ◽  
Ph Cycling ◽  
Baseline Values ◽  
Bovine Enamel ◽  
Early Caries ◽  
Caries Lesions

SUMMARY Most currently marketed fluoride varnishes (FVs) have not been evaluated for their effectiveness in preventing dental caries. The objective of this study was to investigate the anticaries efficacy, measured as fluoride release into artificial saliva (AS); change in surface microhardness of early enamel caries lesions; and enamel fluoride uptake (EFU) of 14 commercially available FVs and two control groups. Bovine enamel specimens (5×5 mm) were prepared and assigned to 18 groups (n=12). Early caries lesions were created in the specimens and characterized using Vickers microhardness (VHNlesion). FV was applied to each group of specimens. Immediately afterward, specimens were incubated in 4 mL of AS for 18 hours, which were collected and renewed every hour for the first six hours. AS samples were analyzed for fluoride using an ion-specific electrode. Specimens were then brushed for 20 seconds with toothpaste slurry and subjected to pH cycling consisting of a four-hour/day acid challenge and one-minute treatments with 1100 ppm F dentifrice for five days. Microhardness was measured following pH cycling (VHNpost). EFU was determined using microbiopsy. Acid resistance (eight-hour demin challenge) was performed after pH cycling, and microhardness was measured (VHNart) and compared with baseline values to test the FV impact after pH cycling. One-way analysis of variance was used for data analysis (α=0.05). FVs differed in their release characteristics (mean ± SD ranged from 14.97 ± 2.38 μg/mL to 0.50 ± 0.15 μg/mL), rehardening capability (mean ± SD ranged from 24.3 ± 15.1 to 11.7 ± 12.7), and ability to deliver fluoride to demineralized lesions (mean ± SD ranged from 3303 ± 789 μg/cm3 to 707 ± 238 μg/cm3). Statistically significant but weak linear associations were found between ΔVHN(post – lesion), EFU, and fluoride release (correlations 0.21-0.36). The results of this study demonstrated that differences in FV composition can affect their efficacy in in vitro conditions.

Combined Effects of Nano-Hydroxyapatite and NaF on Remineralization of Early Caries Lesion

2007 ◽  
Vol 330-332 ◽  
pp. 1347-1350 ◽  
Author(s):  
M.Y. Kim ◽  
H.K. Kwon ◽  
Choong Ho Choi ◽  
B.I. Kim
Keyword(s):  
Statistical Significance ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
P Value ◽  
Distilled Water ◽  
Combined Effects ◽  
Caries Lesion ◽  
Human Enamel ◽  
Early Caries

A previous study reported that many supplements have been added to NaF mouthrinses to improve the remineralization potential. Nano-hydroxyapatite (nano-HA) might also be suitable to this purpose because these nano-size particles can penetrate the enamel pores. Moreover, hydroxyapatite is similar to the inorganic component of teeth and is both bioactive and biocompatible. The aim of this study was to evaluate the combined effects of a nano-HA and fluoride mouthrinse on an early caries lesion in human enamel using an in vitro cycle remineralization and treatment model. Forty-eight human enamel specimens, which had a Vickers Hardness Number (VHN) of 25~45 were artificially demineralized for 48h. There were 8 treatment groups (0%, 1%, 5%, 10% nano-HA in distilled water and the same concentrations of nano-HA in a 0.05% NaF solution). The specimens were incubated in an in vitro remineralization model. After immersing the specimens into the treatment and remineralization solution for 12 hours each, the VHN of each specimen was evaluated for total 24 hours. This step was repeated once again for total 48 hours. The enamel surfaces of all specimens were examined by Confocal Laser Scanning Microscopy (CLSM) and SEM. The statistical significance of the data was identified by one-way ANOVA followed by a Duncan’s studentized range test. A p value < 0.05 was considered significant. The results showed that the degree of remineralization, as revealed by the VHN values, was higher in the NaF groups than in the distilled water groups. The VHNs of the remineralized enamel specimens for 48 hours were higher than after the 24 hours treatment. In addition, the level of remineralization increased with increasing concentration of nano-HA and was more pronounced in the NaF groups than the distilled water groups (p<0.05). The CLSM and SEM images nano-sized particles attached to the enamel in the nano-HA treated groups. Nano-HA might play a synergistic role in remineralization with a fluoride mouthrinse. However, more study will be needed to determine the optimal condition of nano-HA and NaF mouthrinse for human use. In conclusion, nano-HA in a 0.05% NaF mouthrinse can help remineralize an early caries lesion.

scholarly journals Efficacy of amelogenin-chitosan hydrogel in biomimetic repair of human enamel in pH-cycling systems

2015 ◽  
Vol 2 (1) ◽  
pp. 119 ◽  
Author(s):  
Qichao Ruan ◽  
David Liberman ◽  
Rucha Bapat ◽  
Karthik Balakrishna Chandrababu ◽  
Jin-Ho Phark ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Oral Cavity ◽  
Chitosan Hydrogel ◽  
Enamel Defects ◽  
Human Enamel ◽  
Carious Lesions ◽  
Ph Cycling ◽  
Ph Conditions ◽  
Incipient Caries ◽  
Early Caries

Amelogenin-chitosan (CS-AMEL) hydrogel has shown great potential for the prevention, restoration, and treatment of defective enamel. As a step prior to clinical trials, this study aimed to examine the efficacy of CS-AMEL hydrogel in biomimetic repair of human enamel with erosive or caries-like lesions in pH-cycling systems. Two models for enamel defects, erosion and early caries, were addressed in this study. Two pH-cycling systems were designed to simulate the daily cariogenic challenge as well as the nocturnal pH conditions in the oral cavity. After pH cycling and treatment with CS-AMEL hydrogel, a synthetic layer composed of oriented apatite crystals was formed on the eroded enamel surface. CS-AMEL repaired the artificial incipient caries by re-growing oriented crystals and reducing the depth of the lesions by up to 70% in the pH-cycling systems. The results clearly demonstrate that the CS-AMEL hydrogel is effective at the restoration of erosive and carious lesions under pH-cycling conditions.  

scholarly journals Anticariogenic potencial of acidulate solutions with low fluoride concentration

2006 ◽  
Vol 14 (4) ◽  
pp. 233-237 ◽  
Author(s):  
Alberto Carlos Botazzo Delbem ◽  
Gilberto Carlos Tiano ◽  
Karina Mirela Ribeiro Pinto Alves ◽  
Robson Frederico Cunha
Keyword(s):  
Citric Acid ◽  
Dose Response ◽  
Fluoride Concentration ◽  
Response Relationship ◽  
Surface Microhardness ◽  
Dose Response Relationship ◽  
Mouth Rinses ◽  
Ph Cycling ◽  
Bovine Enamel ◽  
Mineral Loss

OBJETIVES: The aim of this study was to verify the anticariogenic effect of acidulate solutions with low NaF concentration, using pH-cycling model and bovine enamel. MATERIAL AND METHODS: Enamel blocks were submitted to the surface microhardness (SMH) test and randomly divided in 12 experimental and one placebo groups. The blocks were submitted to pH cycling for 7 days, with daily applications once/day of 0.05% NaF and 0.1% NaF and twice/day of 0.02% NaF solutions. Four different pH: 4.0, 5.0, 6.0 and 7.0 were used. Next, SMH test was again used to determine the surface microhardness percentage change (%SMH). Data obtained for %SMH were homogeneous and passed through variance analyses and Tukey's test (5%) as far as fluoride concentrations and pH. RESULTS:The results showed that pH influenced %SMH in 0.02% NaF and 0.05% NaF solutions with pH 4.0, which had less mineral loss compared to pH 7.0 (p<0.05). The 0.02% NaF - pH 4.0, and 0.05% NaF - pH 7.0 groups showed similar results (p>0.05). A dose-response relationship was observed among the tested solutions, with better anticariogenic effect for the 0.1% NaF solution. CONCLUSION: The results suggest that the addition of citric acid to acidulate mouth rinses reduce mineral loss.

scholarly journals A modified pH-cycling model to evaluate fluoride effect on enamel demineralization

2003 ◽  
Vol 17 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Rosane Maria Orth Argenta ◽  
Cinthia Pereira Machado Tabchoury ◽  
Jaime Aparecido Cury
Keyword(s):  
Dose Response ◽  
Significant Negative Correlation ◽  
Enamel Surface ◽  
Cross Sectional ◽  
Enamel Demineralization ◽  
Human Enamel ◽  
Ph Cycling ◽  
Dose Response Effect ◽  
Mineral Loss

Since in vitro pH-cycling models are widely used to study dental caries, they should allow evaluations of fluoride effect on early stages of caries development. Therefore, acid etching on enamel surface must be avoided, enabling surface microhardness (SMH) analysis. In the present study, the pH-cycling model originally described by Featherstone et al.9 (1986) was modified to preserve the enamel surface and to produce early carious lesions that could be evaluated using SMH and cross-sectional microhardness (CSMH) measurements. In order to validate this modified model, a dose-response evaluation with fluoride was made. Human enamel blocks with known SMH were submitted to such regimen with the following treatments: distilled deionized water (DDW; control) and solutions containing 70, 140 and 280 ppm F. Data from %SMH change and deltaZ (mineral loss) showed a statistically significant negative correlation between F concentration in treatment solutions and mineral loss. In conclusion, the modified pH-cycling model allowed the evaluation of changes on the outermost enamel layer during caries development, and a dose-response effect of fluoride reducing enamel demineralization was observed.

scholarly journals Effect of Fluoride Concentration on Reduction of Enamel Demineralization According to the Cariogenic Challenge

2016 ◽  
Vol 27 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Mayara dos Santos Noronha ◽  
Dayse Andrade Romão ◽  
Jaime Aparecido Cury ◽  
Cínthia Pereira Machado Tabchoury
Keyword(s):  
Fluoride Concentration ◽  
Caries Risk ◽  
Cross Sectional ◽  
Treatment Groups ◽  
Enamel Demineralization ◽  
Ph Cycling

Abstract Fluoride present in toothpaste at 1,100 µg/g is considered effective on caries control. However, under high cariogenic challenge due to increasing sugar exposure, higher fluoride concentration (5,000 µg/g) could be necessary to compensate the unbalance on caries process. This was tested in a pH-cycling regimen, which evaluated the effect of fluoride concentration relative to toothpaste on reduction of enamel demineralization under conditions of two levels of cariogenic challenge. Enamel slabs (n=20) were subjected to two pH-cycling regimens, simulating 8x and 16x/day sugar exposure and were treated with solutions containing: 0 (no fluoride), 275 or 1,250 µg F/mL, resulting in 6 treatment groups: 4-h/0-F; 8-h/0-F; 4-h/275-F; 8-h/275-F; 4-h/1,250-F and 8-h/1,250-F. The 275 and 1,250 µg F/mL concentrations simulate mouth salivary dilution when 1,100 and 5,000 µg/g toothpastes are used. Enamel demineralization was assessed by surface (%SHL) and cross-sectional hardness. Fluoride taken up by enamel was also evaluated. Data were analyzed by ANOVA one-way and Tukey's test. The treatment with 1,250 µg F/mL significantly reduced %SHL compared with 275 µg F/mL (p<0.05), irrespective the level of cariogenic challenge (4-h/1,250-F vs. 4-h/275-F and 8-h/1,250-F vs 8-h/275-F comparisons, respectively). These data were supported by fluoride concentration found in enamel. These findings suggest that higher fluoride concentrations could partly compensate the greater caries risk under higher cariogenic challenge due to increasing sugar exposure.

scholarly journals In Vitro Enamel Remineralization by Low-Fluoride Toothpaste with Calcium Citrate and Sodium Trimetaphosphate

2013 ◽  
Vol 24 (3) ◽  
pp. 253-257 ◽  
Author(s):  
Edo Hirata ◽  
Marcelle Danelon ◽  
Isabelle Rodrigues Freire ◽  
Alberto Carlos Botazzo Delbem
Keyword(s):  
Artificial Saliva ◽  
Fluoride Concentration ◽  
Surface Hardness ◽  
Positive Control ◽  
Calcium Citrate ◽  
Fluoride Toothpaste ◽  
Sodium Trimetaphosphate ◽  
Ph Cycling ◽  
Bovine Enamel

The objective of this study was to evaluate in vitro the effect of a low fluoride toothpaste (450 µgF/g, NaF) combined with calcium citrate (Cacit) and sodium trimetaphosphate (TMP) on enamel remineralization. Bovine enamel blocks had the enamel surface polished sequentially to determine the surface hardness. After production of artificial carious lesions, the blocks selected by their surface hardness were submitted to remineralization pH cycling and daily treatment with dentifrice suspensions (diluted in deionized water or artificial saliva): placebo, 275, 450, 550 and 1,100 µgF/g and commercial dentifrice (positive control, 1,100 µgF/g). Finally, the surface and cross-section hardness was determined for calculating the change of surface hardness (%SH) and mineral content (%∆Z). Fluoride in enamel was also determined. The data from %SH, %∆Z and fluoride were subjected to two-way analysis of variance followed by Student-Newman-Keuls's test (p<0.05). The mineral gain (%SH and %∆Z) was higher for toothpastes diluted in saliva (p<0.05), except for the 450 µgF/g dentifrice with Cacit/TMP (p>0.05). The 450 Cacit/TMP toothpaste and the positive control showed similar results (p>0.05) when diluted in water. A dose-response was observed between fluoride concentration in toothpastes and fluoride present in enamel, regardless of dilution. It was concluded that it is possible to enhance the remineralization capacity of low F concentration toothpaste by of organic (Cacit) and inorganic (TMP) compounds with affinity to hydroxyapatite.

Effect of New Dentifrice Containing Nano-Sized Carbonated Apatite on Enamel Remineralization

2007 ◽  
Vol 330-332 ◽  
pp. 291-294 ◽  
Author(s):  
S. H. Jeong ◽  
Suck Jin Hong ◽  
Choong Ho Choi ◽  
B.I. Kim
Keyword(s):  
Enamel Surface ◽  
Active Components ◽  
Caries Lesion ◽  
Tooth Structure ◽  
Carbonated Apatite ◽  
Significant Difference ◽  
Ph Cycling ◽  
Carbonated Apatites ◽  
Incipient Caries ◽  
Early Caries

The process of dental caries is dynamic and continuous, with periods of de- and remineralization of the tooth structure occurring over time. When the remineralization potential is superior to demineralization, the caries process can be stopped and early caries lesions can recover. Moreover, the remineralization potential will be increased if active components are added to a dentifrice. Therefore, the aim of this study was to re-evaluate the remineralizaton potential of a dentifrice containing nano-sized carbonated apatite using pH cycling, which simulates the oral environment. Artificial incipient caries was induced on bovine tooth specimens, which were treated with 4 dentifrices containing several concentrations of nano carbonated apatites with pH cycling. The remineralization effect was evaluated at each step by measuring the Vickers Hardness Number, and obtaining SEM and CLSM images of the enamel surface. The micro hardness of the enamel surface increased after the pH cycling treatment of the dentifrices. The dentifrice containing 5% n-CAPs showed the highest level of remineralization followed by 0%, 15% and 30%. One-way ANOVA indicated a significant difference in remineralization between the dentifrice containing 5% and 30% n-CAPs. SEM and CLSM also demonstrated observable differences in each step. From this study, the fluoride dentifrice containing 5% n-CAPs was effective in remineralizing an artificial incipient caries lesion. In conclusion, the dentifrice containing 5% nano carbonated apatites and 25% silica was the most effective in remineralizing early caries lesion.

Solutions and gels containing a sugarcane-derived cystatin (CaneCPI-5) reduce enamel and dentin erosion in vitro

2021 ◽  
Author(s):  
Lethycia Almeida Santos ◽  
Tatiana Martini ◽  
João Victor Frazão Câmara ◽  
Fabiana Navas Reis ◽  
Adriana de Cássia Ortiz ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
Dental Erosion ◽  
Positive Control ◽  
New Approach ◽  
Enamel Erosion ◽  
Ph Cycling ◽  
Bovine Enamel ◽  
Dentin Erosion ◽  
Positive Controls

The effect of solutions and gels containing a sugarcane-derived cystatin (CaneCPI-5) on the protection against enamel and dentin erosion in vitro was evaluated. Bovine enamel and dentin specimens were divided into two groups (n=135 and 153/group for enamel and dentin, respectively) that were treated with solutions or chitosan gels containing 0.1 or 0.25 mg/ml CaneCPI-5. The positive controls for solutions and gels were Elmex Erosion Protection™ solution and NaF gel (12,300 ppm F), respectively. Deionized water and chitosan gel served as controls, respectively. The solutions were first applied on the specimens for 1 min and the gels for 4 min. Stimulated saliva was collected from 3 donors and used to form a 2 h acquired pellicle on the specimens. Then, the specimens were submitted to an erosive pH cycling protocol 4 times/day for 7 days (0.1% citric acid pH 2.5/90s, artificial saliva/2h, artificial saliva overnight). The solutions and gels were applied again during pH cycling, 2 times/day for 1 min and 4 min, respectively, after the first and last erosive challenges. Enamel and dentin losses (µm) were assessed by contact profilometry. Data were analyzed by 2-way ANOVA and Tukey´s test (p <0.05). All the treatments significantly reduced enamel and dentin loss in comparison with controls. Both CaneCPI-5 concentrations had a similar protective effect against enamel erosion, but only the higher concentration was as effective against dentin erosion as the positive control. Regarding the vehicles, only the 0.1 mg/ml gel performed worse than the positive control for dentin. CaneCPI-5 reduced enamel and dentin erosion to a similar extent as the fluoride-containing vehicles. However, dentin requires higher CaneCPI-5 concentrations, in the case of gels. Solutions or gels containing CaneCPI-5 might be a new approach to protect against dental erosion.

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