Caries-like Lesions Research Articles

Comparison of hydroxyapatite and fluoride oral care gels for remineralization of initial caries: a pH-cycling study

ObjectiveThe present in vitro study investigated if simulated daily use of hydroxyapatite-based gel (15% HAP) remineralizes early caries lesions as effective as weekly use of high fluoride (12,500 ppm) concentration gel, comparing them with artificial saliva alone.Materials and methodsThree tooth blocks were produced from each of 20 bovine teeth. Caries-like lesion was created on each block by 4-day demineralization in acidified gel. The blocks were randomized into three remineralization groups (20 blocks/group); Hydroxyapatite-based gel (Karex gelée, 15% HAP, fluoride-free), fluoride-based gel (Elmex gelée, 12,500 ppm F−), and artificial saliva (AS). Remineralization was conducted using pH-cycling model for 28 days with storage in AS. The pH cycling model consisted of 2 h demineralization once daily for all groups, and 3 min HAP gel application once daily, 3 min fluoride gel application once weekly, or remain in AS only respectively. Baseline and post-test mineral loss were quantified using microradiography.ResultsPaired t-tests (baseline vs. post-Test) indicated significant (p < 0.0001) remineralization in all groups. When compared against each other using Games-Howell’s multiple comparison test, no significant difference in remineralization was observed between the two gels, but both gels exhibited significantly (p < 0.001) higher percentage mineral gain (HAP:39 ± 7%; fluoride:41 ± 11%) than AS alone (6 ± 2%).ConclusionHydroxyapatite-based gel (15% HAP) was as effective as fluoride-based gel (12,500 ppm F−) in remineralizing initial caries lesion.

Microtensile bond strength of TTEMA/TEGDMA remineralizing adhesive to early carious enamel lesions

Objectives: Resin adhesive could be used as a carrier of nano-hyrdoxy apatite particles added to treat early enamel caries. The aim of this study was to evaluate microtensile bond strength of a remineralizing enamel infiltrant to early carious enamel lesion. Methods: An artificial caries model was used to induce early partially-cavitated enamel caries-like lesion in maxillay centrals. Nano hydroxyapatite particles (nHA) were applied in two forms to a low shrinkage low viscosity resin adhesive: particles were directly added to resin adhesive or silanated before addition. Unmodified ad-hesive was used as control. Micro-tensile bond strength (MTBS) was performed to evaluate bond strength to demineralized enamel after application of the remineralizing resin adhesive (n=20, α=0.05). Scanning electron microscopy (SEM) was performed to assess mode of failure and to study infiltrant-enamel interface. Results: Direct addition of nano-particles resulted in significant reduction (F=32, P<0.001) in MTBS (19 MPa ± 3.8) compared to addition of silanated particles (24 MPa ± 3.2) which presented comparable values to the unmodified enamel infiltrant (26 MPa ± 4.1). SEM image analysis revealed adhesive failure observed for directly added particles while the other two groups demonstrated cohesive failure observed in the resin adhesive. On the other hand, direct addition of nHA resulted in partial remineralization of enamel (42% recovery in calcium content). Conclusions: TTEMA/TEGDMA enamel infiltrant could be used as a carrier for nano hydroxyapatite particles without compromising bond strength to early carious enamel lesions.

The enamel remineralization potential of fluoride varnishes containing arginine

ObjectivesTo examine the effect of incorporating arginine in a 5% sodium fluoride (NaF) varnish on its remineralization potential and HGF-1 cytotoxicity. MethodsExperimental varnishes were prepared using two arginine variants: l-arginine (Arg) and l-arginine monohydrochloride (Arg.HCl) at 2%, 4%, & 8% w/v. with control 5% NaF varnish. Sound enamel specimens with varnish treatments were subjected to a 4-day demineralization assay and surface roughness analysis using AFM (n = 3). Enamel specimens with artificial incipient caries-like lesions were subjected to a remineralization assay (n = 6) and an 8-day pH-cycling (n = 3). For remineralization assay, enamel F/Arg-uptake and Ca/PO43−i-content were estimated. During pH-cycling, EDX mapping for Ca/F-content and mineral density using micro-CT were assessed. The HGF-1 cytotoxicity of the varnishes was examined using MTT/CCK-8 assay. ResultsThe Ca-content/F-uptake of the 2% Arg-NaF varnish treated specimens were significantly higher than other varnishes (p < 0.05). The 2% Arg-NaF had significantly higher remineralization potential than NaF (p < 0.001), suggesting Arg-Ca-F complex formation post-varnish application. The 8% Arg-NaF exhibited significantly more pronounced cytotoxicity to HGF-1 cells than 2% Arg-NaF (p < 0.001) and NaF varnish. ConclusionsIncorporation of 2% Arg in NaF varnish enhanced the enamel remineralization potential of NaF varnish; while 8% Arg in NaF varnish was cytotoxic to HGF-1. Clinical SignificanceA professionally deliverable l-arginine-enriched NaF varnish for caries prevention addresses a global public health priority. The synergism between l-arginine and NaF varnish counters the limited antimicrobial effects of fluorides and supports acquisition of a balanced oral microbiome. The combined arginine-fluoride varnish will provide the much-needed ecological-based approach for caries prevention.

REMINERALIZATION EFFECT OF EGG SHELL POWDER AND NOVAMINE ON INITIAL CARIES-LIKE LESIONS IN YOUNG PERMANENT TEETH (IN-VITRO STUDY)

Introduction: Despite the cariostatic effect of fluoride, the continuous use of fluoridated toothpastes increases the risk of dental fluorosis. Therefore, new safe alternative technologies of teeth remineralization must be introduced to arrest dental caries and remineralize the early enamel carious lesions. Objectives: The aim of the study was to evaluate the remineralizing effect of eggshell powder and novamine on initial caries-like lesions in young permanent teeth compared to fluoride. Material and Methods: A total of 96 permanent teeth were selected. Each Tooth was coated with nail varnish, leaving squares of 4x4 mm. Each tooth was sectioned into 2 halves longitudinally in a buccolingual direction through the center of the window to obtain a mesial and a distal half (192 specimens). One half was treated and the other half was remained untreated to serve as its negative control. Teeth were assigned into three groups according to treatment agent; group I (eggshell powder solution), group II (novamine toothpaste) and group III (fluoride toothpaste) .Specimens were immersed in the demineralizing solution for 72 hours to produce artificial carious lesions on the exposed enamel surface. Results: There was a statistically significant mean microhardness and lesion depth values between test subgroups IA (eggshell powder), IIA (novamine) and their controls (P 0.001). There was statistically significant difference in mean percent difference values of enamel microhardness among three groups (P 0.001). Conclusions: Both eggshell powder and novamine were effective for remineralization of initial caries-like lesions of young permanent teeth.

Enamel Subsurface Caries-Like Lesions Induced in Human Teeth By Different Solutions: A TMR Analysis.

This study assessed the effectiveness of models for developing subsurface caries lesions in vitro and verified mineral changes by transverse microradiography (TMR). Enamel blocks from permanent (n=5) and deciduous teeth (n=5) were submitted to lesion induction by immersion in demineralizing solutions during 96 h, followed by pH cycles of demineralization (de) and remineralization (re) for 10 days. Two de-/re solutions were tested. Demineralizing solution "A" was composed by 2.2 mM CaCl2, 2.2 mM KH2PO4, 0.05 M acetic acid, with pH 4.4 adjusted by 1 M KOH. Demineralizing solution "B" was composed by 2.2 mM CaCl2, 2.2 mM NaH2PO4, 0.05 M acetic acid and 0.25 ppmF, with pH 4.5 adjusted by 1M KOH. Solution "A" produced cavitated lesions in permanent teeth, whereas solution "B" led to subsurface lesions in deciduous teeth. Solution "B" was then tested in enamel blocks from permanent teeth (n=5) and subsurface lesions were obtained, so that solution "B" was employed for both substrates, and the blocks were treated with slurries of a fluoride dentifrice (1450 ppm F, as NaF, n=5) or a fluoride-free dentifrice (n=5). Solution "B" produced subsurface lesions in permanent and primary teeth of an average (±SD) depth of 88.4µm (±14.3) and 89.3µm (±15.8), respectively. TMR analysis demonstrated that lesions treated with fluoride-free dentifrice had significantly greater mineral loss. This study concluded that solution "B" developed subsurface lesions after pH cycling, and that mineral changes were successfully assessed by TMR.

EFFECTIVENESSOF CASEIN PHOSPOPEPTIDE AMORMPHOUS CALCIUM PHOSPHATE WITH OR WITHOUT FLUORIDE ON REMINELIZATION OF ENAMEL CARIES- LIKE LESIONS IN PRIMARY TEETH

Abstract: Objective: To evaluate and compare the remineralization effect of casein phospho-peptide amorphous calcium phosphate with or without fluoride “MI paste”&“MI Paste Plus” respectively” on the re-mineralization of enamel caries-like lesions in primary teeth. Material and methods: Artificial caries lesion was made on the labial surface of 40 extracted or exfoliated sound primary teeth which were then divided into 2 halves; one half was treated with one of the tested remineralizing agent “MI paste” or “MI Paste Plus”” while the other half served as a control. The lesions were evaluated both qualitatively using a polarized light microscope and quantitatively by measuring “calcium and phosphate” content using “energy-dispersive X-ray spectroscopy”. Data were collected and analyzed by using paired t-test to compare the control and the study groups for each material, while the “t-test” was used to compare between the two study groups. Results: Both “MI paste” and “MI Paste Plus” showed significant re-mineralization to the subsurface enamel lesions. “MI Paste Plus” showed significantly better results than “MI paste” with an increased amount of calcium “t=5.59 p=<0.0001”, Ca/phosphate ratio “t=4.08 p=0.003” and reduction in the amount of phosphate content “t=4.57 p= 0.001”. Conclusion: Both “MI paste” and “MI Paste Plus” were effective in enamel remineralization, the addition of fluoride in “MI Paste Plus” acted synergistically with the casein phospho-peptide amorphous calcium phosphate and gave better remineralization effect on enamel.

Remineralizing Effect of Nanofilled Glass Ionomer Combined with Titanium Dioxide Nanoparticle and Nanohydroxyapatite in Root Caries-like Lesions

Purpose: This study designed to evaluate the remineralizing effect of nanofilled glass ionomer combined with titanium dioxide nanoparticle and nano hydroxyapatite in root caries like-lesions. Materials and Methods: sixty specimens from sound human premolars, standardized rounded class V cavities were prepared in the middle of cervical one third of the labial surface of root. Then the specimens were divided into three main groups according to the experimental restored material (20 specimens each). Group (A): received nanofilled glass ionomer (NGI), group (B): received 10% nano hydroxyapatite (NHA) incorporated into conventional glass ionomer (GI), and group (C): received 10% titanium dioxide nanoparticles (TiO2NPs) incorporated in conventional glass Ionomer (GI). Each group was further subdivided into two subgroups of (10 each), according to the topical application of nano hydroxyapatite solution either the surface was treated with 10% nano hydroxyapatite solution (I), or the surface was not treated (II). EDAX measurements were done for all specimens before demineralization, after demineralization, and after remineralization. Results: all materials caused significance remineralization of dentin. When comparing the materials effect on remineralization, (NHA) and (NGI) had much higher phosphors and calcium % change than (TiO2 NPs) when used without (NHA) coat. In comparing use of coat of NHA solution, results showed no significant effects in remineralization, except with TiO2 NPs. Conclusion: Modification of conventional GI restorations using nanoparticles is beneficial to dentin remineralization. NHA topical coat has limited beneficial effect when used in conjunction with NHA and NGI restoration. TiO2 NPs although produces remineralization, is of lesser value than NHA.

Quantitative evaluation of remineralizing potential of three agents on artificially demineralized human enamel using scanning electron microscopy imaging and energy-dispersive analytical X-ray element analysis: An in vitro study

The aim of this study is to quantitatively evaluate the remineralization potential of three remineralizing systems as follows: fluoride, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and CPP-ACP with fluoride, under scanning electron microscope with energy-dispersive X-ray analysis. In this in vitro study A total of 40 enamel specimens were prepared from the buccal or lingual surfaces of human premolars extracted for orthodontic reason. Specimens were then placed in demineralizing solution for 96 h, to produce artificial caries-like lesion. Calcium and phosphate weight percentage of demineralized specimens was measured. Specimens were divided into four groups as follows: (a) control, (b) CPP-ACP, (c) CPP-ACP with fluoride, and (d) fluoride varnish. Except for the control group, the entire specimens were subjected to remineralization using respective remineralizing agents of their groups. The prepared specimens were assessed for calcium and phosphate weight percentage using scanning electron microscopy-energy dispersive X-ray spectroscopy. One way analysis of variance (ANOVA), followed by Tukey's test, was performed with the help of critical difference (CD) or least significant difference at 5% and 1% level of significance. P ≤ 0.05 was taken to be statistically significant and P < 0.001 as statistically highly significant. The mean weight percentage of calcium and phosphorus of specimens treated with CPP-amorphous calcium phosphate nanocomplexes plus fluoride (ACPF) was significantly higher than other groups. All the groups showed statistically significant remineralization. However, because of added benefit of fluoride, CPP-ACPF showed statistically significant amount of remineralization than CPP-ACP.

Effect of CPP-ACP on remineralization of artificial caries-like lesion: an in situ study.

The purpose of this double-blind, randomized, crossover in situ study is to compare remineralization of preformed enamel lesions by casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) and fluoride dentifrice products. During each of four 10-day experimental legs, 10 participants wore intraoral removable palatal acrylic appliances with four human enamel slabs with preformed lesions. A 0.03-mL treatment paste was dripped extraorally onto the enamel blocks once a day for 3 min. The four randomly allocated treatments were as follows: CO- Control: silica dentifrice without fluoride; MP: MI Paste; MPP: MI Paste Plus and FD: Fluoride dentifrice - 1100 ppm F as NaF). Knoop surface hardness (SH) test was performed in three stages (T0 - sound enamel, T1 - after preformed lesion, and T2 - after treatment) and the cross-sectional hardness (CSH) test was performed after treatment using a 50-gram Knoop load for 15 s. Knoop hardness number (KHN) was similar between treatments. %SHr was significantly higher in the MP, FD, and MPP when compared to CO group (Kruskal-Wallis and Mann-Whitney tests, p < 0.05). Harder enamel was found in MP (75 μm) and FD groups at 75 to 175 μm. Treatment with DF, MP, and MPP promoted an increase of 20.27%, 19.24%, and 14.71%, respectively, in Integral Hardness Change (ΔIHC) when compared to CO (p<0.05). Remineralizing agents (MP, MPP, and DF) were able to inhibit demineralization of human enamel subjected to high cariogenic challenge in situ. DF had the greatest preventive potential against the progression of carious lesions.

EFFECT OF TWO REMINERALIZING AGENTS ON MICROHARDNESS OF INITIAL ENAMEL CARIESLIKE LESIONS IN YOUNG PERMANENT TEETH

INTRODUCTION: Dental caries in enamel is unique amongst diseases as enamel is both acellular and avascular. Thus, in contrast to other tissues, enamel cannot heal itself by a cellular repair mechanism. Nonetheless, it is now well established that the formation of incipient enamel caries is a reversible process where periods of progression alternates with periods of remineralization. OBJECTIVES: The purpose of this study was to compare the effect of Nano-hydroxyapatite paste and casein phosphopeptide-amorphous calcium phosphate fluoride paste remineralizing capacity on initial enamel carious lesions of young permanent teeth. MATERIALS AND METHODS: Sixty extracted young permanent teeth with a standardized window on enamel were immersed in a demineralizing solution for 48 hours to produce subsurface enamel lesions. They were divided into three groups according to remineralizing agents (N=20): group I: Nano-hydroxyapatite paste; group II: casein phosphopeptide-amorphous calcium phosphate fluoride paste; and group III: control (untreated). The enamel surface microhardness (SMH) was measured at baseline, after incipient enamel lesion formation and after treatment. RESULTS: The mean surface microhardness (201.46) was found to be higher in teeth treated with Nano-hydroxyapatite paste than mean surface microhardness (195.61) in those treated with casein phosphopeptide-amorphous calcium phosphate fluoride paste. However, this difference was not statistically significant P=0.26. CONCLUSIONS: Both Nano-hydroxyapatite paste and casein phosphopeptide-amorphous calcium phosphate fluoride paste were effective for remineralization of early caries-like lesions of young permanent teeth.

Effects of Dentifrices Differing in Fluoride Content on Remineralization Characteristics of Dentin in vitro

Objectives: The aim of this study was to compare the caries preventive effect of highly fluoridated dentifrices and gels on sound dentin as well as on artificial dentin caries-like lesions. Methods: Bovine dentin specimens (n = 240), with 2 different surfaces each (1 sound surface [sound treatment (ST)] and one caries lesion [demineralized treatment (DT)]), were prepared and randomly allocated to one highly (6 × 120 min demineralization/day [H]) and one lowly cariogenic (6 × 60 min demineralization/day [L]) pH-cycling model. Treatments during pH-cycling (28 days) were: brushing 2×/day with: 0 ppm F [H₀/L₀], 1,450 ppm F [H_1,450/L_1,450], 2,800 ppm F [H_2,800/L_2,800], 5,000 ppm F [H_5,000/L_5,000], 5,000 ppm F plus TCP [H_5,000+TCP/L_5,000+TCP], and 12,500 ppm F [H_12,500/L_12,500] containing dentifrices/gels. Dentifrice/gel slurries were prepared with deionized water (1:2 wt/wt). Differences in integrated mineral loss (∆∆Z) and ∆ lesion depth were calculated between values before and after pH-cycling using transversal microradiography. Results: The correlation between ΔΔZ_DT and F^– was strong for the highly (r_H = 0.691; p < 0.001) and moderate (r_L = 0.500; p < 0.001) for the lowly cariogenic model, indicating a fluoride dose-response for both. Significant differences for ΔΔZ_DT and ΔΔZ_ST could be found between H₀, H_1,450, H_5,000, and H_12,500 as well as L₀, L_5,000, and L_125,000 (p ≤ 0.046; analysis of covariance [ANCOVA]). Except for 0 ppm F^–, no significant difference in ΔΔZ_ST and ΔΔZ_DT could be found between the highly and lowly cariogenic model (p ≥ 0.056; ANCOVA). Conclusion: For both pH-cycling conditions a dose-response for fluoride could be revealed. For elderly people with exposed root surfaces, the use of gels containing 12,500 ppm F instead of regularly (1,450 ppm F) or highly (5,000 ppm F) fluoridated dentifrices should be further investigated, as it offered higher caries-preventive effects in vitro.

Root caries lesions inhibition and repair using commercial high-fluoride toothpastes with or without tri-calcium phosphate and conventional toothpastes containing or not 1.5% arginine CaCO3: an in situ investigation.

This double-blind, crossover, and in situ study evaluated the effect of commercial high-F toothpastes with or without functionalized β-tri-calcium phosphate (fTCP) and conventional-F toothpaste containing or not 1.5% arginine-CaCO3 in preventing and repairing root caries-like lesions. Twelve volunteers wore palatal appliances containing sound (S) and pre-demineralized (PD) bovine root dentin blocks in 4 phases of 14days/each. They used F toothpastes, 3×/day: (i) 1,450μgF/g (conventional-F); (ii) 1,450μgF/g + 1.5% arginine-CaCO3 (conventional-F + arginine/CaCO3); (iii) 5,000μgF/g (high-F); and (iv) 5,000μgF/g (high-F + fTCP). Sucrose solution (20%) was dropped 8×/day on the S blocks. The demineralization in the S blocks and the remineralization in the PD ones were estimated by % of surface hardness difference (%SH-S) and % of SH recovery (%SHR-PD), respectively. Caries lesion area (ΔS) was determined in the blocks. Statistical analyses were performed by one-way ANOVA/Kruskal-Wallis and multiple comparisons tests (p < 0.05). Both high-F toothpastes presented similar effect to prevent early caries lesions and it was higher than conventional-F + arginine/CaCO3. All treatments resulted in significantly lower ΔS values compared with conventional-F toothpaste (p < 0.0001). High-F + fTCP showed non-significantly higher preventive and reversible effect compared to high-F. The effect of conventional-F + arginine/CaCO3 was similar to high-F and lower than high-F + fTCP in preventing and reverting in-deep caries lesions. Overall, high-F toothpastes seem to be more effective and interesting feasible strategy for both prevention and remineralization actions in root dentin. With the trend of increasing dentin root caries, this study brings new evidences about the preventive and repair effect of high-F toothpastes with or without fTCP in root caries and support the use of arginine in toothpastes.

Microtensile bond strength of a self-etch adhesive used as a carrier for a remineralizing agent

Objectives: resin adhesive could be used as a carrier of nano-hyrdoxy apatite particles added to treat early enamel caries. The aim of this study was to evaluate microtensile bond strength of a remineralizing adhesive to early carious enamel lesionMethods: an artificial caries model was used to induce early non cavitated enamel caries-like lesion in maxillay centrals. Nano hydroxyapatite particles (nHA) were applied in two forms to a self-etch resin adhesive: particles were directly added to resin adhesive or silanated before addition. Unmodified adhesive was used as control. Micro-tensile bond strength (MTBS) was performed to evaluate bond strength to demineralized enamel after application remineralizing resin adhesive (n=20, α=0.05). Scanning electron microscopy (SEM) was performed to assess mode of failure and to study adhesive enamel interface. Results: Direct addition of nano-particles resulted in significant reduction (F=32, P<0.001) in MTBS (12 MPa±3.8) compared to addition of silanated particles (24 MPa ± 3.2) which presented comparable values to the control group (26 MPa ± 4.1). SEM image analysis revealed adhesive failure observed for directly added particles while the other two groups demonstrated cohesive failure observed in the resin adhesive. Direct addition of nHA resulted in partial remineralization of enamel (42% recovery in calcium content. Conclusions: Self-etch resin adhesive could be used as a carrier for nano hydroxyapatite particles without compromising bond strength to early caries-like enamel lesions.

REMINERALIZATION EFFECT OF FLUORIDE VARNISH CONTAINING CASEIN PHOSPHOPEPTIDE AMORPHOUS CALCIUM PHOSPHATE ON CARIES-LIKE LESIONS IN PRIMARY TEETH (IN VITRO STUDY)

INTRODUCTION: Fluoride containing casein phosphopeptide amorphous calcium phosphate (CPP-ACP) varnishes are now available as (MI Varnish). It has an effect on the remineralization process of demineralized enamel, since it has the highest release of calcium and fluoride ions. OBJECTIVES: To study the remineralizing effect of fluoride varnish containing casein phosphopeptide amorphous calcium phosphate (MI varnish) on the remineralization of caries-like lesions in primary teeth compared to sodium fluoride varnish. MATERIALS AND METHODS: Twenty-four freshly extracted primary maxillary incisors with standardized 4x4 windows were immersed in demineralizing solution for four days. Teeth were divided into two groups, group I (n=12 teeth); MI varnish and group II (n=12 teeth); Prevident varnish. They were sectioned into two halves in a buccolingual direction (48 specimens). One half was treated with the remineralizing agent and the other half remained untreated and served as its control. Specimens were assigned into subgroup I A (MI varnish) n=12 specimens, subgroup I B (untreated) n=12 specimens, subgroup II A (Prevident varnish) n=12 specimens and subgroup II B (untreated) n=12 specimens. Specimens were subjected to pH cycling for ten days. The specimens were evaluated quantitatively using energy dispersive x-ray spectrometer (EDX). RESULTS: MI varnish treated specimens (subgroup I A) showed significant high mean Ca, Ca/P ratio than the untreated specimens. Also, Prevident varnish treated specimens showed significant high mean Ca, Ca/P ratio than the untreated specimens. Median percent change of Ca/P ratio of MI varnish treated specimens was significantly higher than Prevident varnish treated specimens. CONCLUSIONS: Fluoride varnish containing CPP-ACP has a higher remineralization potential of the caries-like lesion in primary teeth in comparison to sodium fluoride varnish.

Adjunctive use of fluoride rinsing and brush-on gel increased incipient caries-like lesion remineralization compared with fluoride toothpaste alone in situ

Objective: The objective of this study was to compare the remineralizing effect of sodium fluoride (NaF) mouth rinse or NaF gel as an adjunct to NaF dentifrice on incipient caries-like lesions in an in situ cross-over design study, with three sessions of 30 days each.Materials and methods: Orthodontic brackets with artificial demineralized enamel slabs were attached to the upper first molars of 12 participants. A set of 3 test specimens from the same tooth was randomly assigned to each participant and allocated into three 30-day sessions: 1) brushing with 0.22% NaF dentifrice 2 times/day (F dentifrice), 2) brushing with 0.22% NaF dentifrice 2 times/day+ rinsing with 0.05% NaF before bedtime (F mouth rinse), 3) brushing with 0.22% NaF dentifrice 2 times/day + brushing with 1.1% NaF gel before bedtime (F brush-on gel). The mineral gain and lesion depth of the specimens were evaluated by micro-computed tomography.Results: The mean mineral gain from the NaF mouth rinse and the NaF brush-on gel was similar, but greater than that from the NaF dentifrice (p < .05). The NaF brush-on gel yielded the greatest mean depth of remineralization (168 µm), followed by the NaF mouth rinse (144 µm). Both depths were significantly greater than that of the NaF dentifrice (84 µm) (p < .05).Conclusions: Both 0.05% NaF mouth rinse and 1.1% NaF brush-on gel, used at bedtime, increased incipient caries-like lesion remineralization in situ in combination with brushing with NaF dentifrice twice a day.

Is Novamin Toothpaste Effective on Enamel Remineralization? An In-Vitro Study

Objectives: New bio-active glass containing toothpaste (NovaMin) is one of the most effective cariostatic products when used as a daily application the aim of this in-vitro study is to evaluate the influence of NovaMin on enamel remineralization.Materials and Methods: Twenty-eight sound human enamel samples were randomly divided into four groups (A-D) each having seven samples as follows: A (Novamin), B (1450 ppm NaF and Novamin), C (CPP-ACP), D (1450ppm NaF). After inducing caries-like lesions, each group was maintained daily for demineralization-remineralization cycle for seven days. During this cycle, samples were treated by the selected toothpaste for each group. Enamel mineral loss was assessed by surface microhardness. Surface enamel microhardness was determined on the enamel blocks. Non-parametric Kruskar-Wallis test compares the amount of surface microhardness recovery (SMHR%) across four different toothpastes.Results: PLM data revealed a mineral precipitation band on the surface layer of all toothpastes; however, when compared to treated lesions, no statistically significant differences among the groups (p&amp;gt;0.05) were found. Conclusions: NovaMin containing dentifrice has similar remineralization potential on carious-like lesions when compared to fluoride containing dentifrices.

Microhardness of bovine enamel after different fluoride application protocols.

The aim of the present study was to evaluate microhardness, mineral recovery and the enamel surface after the application of topical fluoride to artificial dental caries. Twenty-five bovine enamel blocks were prepared for artificial caries-like lesions and randomly divided into five groups (n=5): untreated (C control), 1.23% acidulated phosphate fluoride gel (APG), 2% neutral fluoride gel (NFG), 1.23% acidulated fluoride mousse (AFM) and fluoride varnish (5% Duraphat, DFV). Knoop microhardness (KHN) was evaluated after 7 and 14 days of treatment as well as 1 week after 28 days of treatment. Electron and confocal microscopy and energy dispersive spectroscopy were performed. KHN data were treated with two-way ANOVA (material×time) and Tukey's test at a 5% significance level. Differences were found among groups over time (p<0.001). Microhardness varied after 7 and 14 days of treatment and remained stable 1 week after 28 days of treatment. Mineral recovery and enamel topography varied among groups, with the fluoride varnish achieving the most uniform topography.

Effect of iontophoresis on fluoride uptake in enamel with artificial caries lesion.

Iontophoresis is a noninvasive technique, based on the application of a constant low-intensity electric current to facilitate the release of a variety of drugs, whether ionized or not, through biological membranes. The objective of this research was to evaluate the effect of iontophoresis using different electric current intensities on the uptake of fluoride in dental enamel with artificial caries lesions. In this in vitro operator-blind experiment, bovine enamel blocks (n = 10/group) with caries-like lesions and predetermined surface hardness were randomized into 6 groups: placebo gel without fluoride applied with a current of 0.8 mA (negative control), 2% NaF gel without application of any current, and 2% NaF gel applied with currents of 0.1, 0.2, 0.4 and 0.8 mA. Cathodic iontophoresis was applied for 4 min. The concentration of loosely bound fluoride (calcium fluoride) and firmly bound fluoride (fluorapatite) was determined. The results were analyzed by the nonparametric Kruskal-Wallis and Dunn tests. Iontophoresis at 0.8 mA, combined with the application of fluoridated gel (2% NaF), increased fluoride uptake in enamel with caries-like lesions, as either calcium fluoride or fluorapatite.

Enhancing the Remineralization Potential of Child Formula Dentifrices: An In Vitro Study.

Objective(s): The incorporation of Arginine (Arg) in NaF-containing child dentifrice might enhance its remineralizing potential, reducing fluorosis risk with significant anti-caries benefit. The study objective was to examine the remineralizing potential of arginine in child formula dentifrice (600-ppm NaF).Study Design: Primary teeth enamel specimens (n = 10) with artificial caries-like lesion were randomly divided to 4 treatment groups: A: 2% Arg-(600-ppm) NaF; B: 600-ppm NaF; C: 1100-ppm NaF; and D: deionized water subjected to 7-day pH-cycling. The mineral density (MD) of the treated specimens was assessed using micro-CT. The pre-/post-treated artificial caries-like lesion were acid-etched for enamel fluoride uptake (EFU) evaluation, Ca and P element analysis using ICP-OES, and the inorganic phosphate (PO43-) determination using colorimetric assay. Results: The percentage remineralization of the 2% Arg-NaF and 1100-ppm NaF groups was significantly higher than the 600-ppm NaF group (p<0.001). However, no significant difference in remineralization was observed between the two groups (p>0.05). The EFU, Ca/P ratio, PO43- content of the 2% Arg-NaF group were significantly higher than the 600-ppm NaF group (p<0.01); while no significant difference was found between the 2% Arg-NaF and 1100-ppm NaF groups. Conclusion: Within the limitations of the present study, incorporation of 2% arginine in 600-ppm NaF child formula dentifrice enhanced the remineralization potential of artificial enamel caries, to a level comparable to 1100-ppm NaF adult formula dentifrice.

Comparison of Remineralising Potential of Nano Silver Fluoride, Silver Diamine Fluoride and Sodium Fluoride Varnish on Artificial Caries: An In Vitro Study.

To evaluate the remineralisation effect of an experimental nano silver fluoride (NSF) formulation using an in vitro remineralisation model, compared with silver diamine fluoride (SDF) and sodium fluoride varnish (NaF) in current clinical use. 45 sound human third molars were sectioned in buccolingual and mesiodistal direction and 180 enamel specimens were divided into four groups (NSF; SDF; NaF; Control). Early caries-like lesions were artificially created. Remineralisation agents were applied with a microbrush for 2 min in NSF and SDF group; NaF varnish were applied in a thin layer and then all specimens were stored in a moist environment at 37°C for 24 h. Each group was subjected to a pH cycling model for 7 days. The Vickers microhardness values (VHN) of specimens were compared before treatment, after demineralisation and after remineralisation. In addition, scanning electron microscope (SEM) images were investigated to compare morphological changes on the surfaces. Kruskal-Wallis and Mann-Whitney U tests were used for statistical analysis to compare the groups at p < 0.05. All remineralisation agents were found to be statistically significant for the rehardening of the demineralised enamel specimens (p < 0.001). There was a statistically significant difference between the all groups after remineralisation (p < 0.001). The VHN values for postdemineralisation were determined as, respectively, NaF (229.96) > SDF (222.96) > NSF (191.36) > Control (175.80). SEM images have also supported the microhardness values. NSF was not found to be effective as sodium fluoride varnish and SDF on artificial enamel caries lesions. Additional investigation is needed to recommend it as an alternative agent to routine fluoride treatments.