Effect of treatment with phosphate, casein phosphopeptide and fluoride on the remineralization: in vitro study.

This study aimed to evaluate in vitro the effect protocols and anticaries agents containing casein amorphous calcium fluoride phosphopeptide-phosphate (CPP-ACPF, MI Paste Plus), sodium trimetaphosphate (TMP) and fluoride (F), in remineralization of caries lesions. Bovine enamel blocks with initial caries lesions were divided into groups (n = 12): 1) Toothpaste without F-TMP-MI Plus (Placebo); 2) Toothpaste 1100 ppm F (1100F), 3) 1100F + MI Paste Plus (1100F-MI Paste Plus), 4) Toothpaste with 1100F + Neutral gel with 4,500 ppm F + 5%TMP (1100F + Gel TMP) and 5) Toothpaste with 1100F + Neutral gel with 9,000 ppm F (1100F + Gel F). For the 4 and 5 groups the gel was applied only once for 1 minute, initially to the study. For the 3 group, after treatment with 1100F, MI Paste Plus was applied 2x/day for 3 minute. After pH cycling, the percentage of surface hardness recovery (%SHR); integrated loss of subsurface hardness (ΔKHN); profile and depth of the subsuperficial lesion (PLM); concentrations of F, calcium (Ca) and phosphorus (P) in enamel was determined. The data were analyzed by ANOVA (1-criterion) and Student-Newman-Keuls test (p < 0.001). Treatment with 1100F alone led to ~ 28% higher remineralization when compared to treatment with 1100F associated with MI Paste Plus (p < 0.001). The 1100F and 1100F + Gel F groups showed similar values for %SHR (p = 0.150). 1100F + Gel TMP treatment also remineralized the enamel surface by ~ 30% and 20% when compared to the 1100F + Gel F and 1100F groups (p < 0.001). The lower lesion depth (ΔKHN) was observed for the 1100F + Gel TMP group (p < 0.001), where it was 54% and 44% lower in comparison to the 1100F and 1100F + Gel F groups (p < 0.001). Polarized light microscopy photomicrographs showed subsurface lesions in all groups, but these lesions were present to a lower extent in the 1100F + Gel TMP group (p < 0.001). Treatment with 1100F + Gel TMP promoted an increase in the concentration of Ca in the enamel by ~ 57% and ~ 26% when compared to the 1100F and 1100F + MI Paste Plus groups (p < 0.001), respectively. There were no significant differences between the 1100F, 1100F + MI Paste Plus and 1100F + Gel F groups (p > 0.001). Similar values of P in the enamel were observed in the 1100F, 1100F + MI Paste Plus and 1100F + Gel F groups (p > 0.001), except for the 1100F + Gel TMP group, which presented a high concentration (p < 0.001). We conclude that the 1100F+TMP gel treatment/protocol led to a significant increased remineralization when compared to the other treatments/protocols and may be a promising strategy for patients with early caries lesions.

Microhardness and elemental analysis of ion-releasing restoration/ dentin interface following enzymatic chemomechanical caries excavation.

BACKGROUND: This study was conducted to compare chemical, elemental and surface properties of sound and carious dentin after application of two restorative materials resin-modified glassionomer claimed to be bioactive and glass hybrid restorative material after enzymatic chemomechanical caries removal (CMCR) agent. METHODS: Forty carious and twenty non-carious human permanent molars were used. Molars were randomly distributed into three main groups: Group 1 (negative control) - sound molars, Group 2 (positive control) - molars were left without caries removal and Group 3 (Test Group) caries excavated with enzymatic based CMCR agent. After caries excavation and restoration application, all specimens were prepared Vickers microhardness test (VHN), for elemental analysis using Energy Dispersive Xray (EDX) mapping and finally chemical analysis using Micro-Raman microscopy. RESULTS: Vickers microhardness values of dentin with the claimed bioactive GIC specimens was statistically higher than with glass hybrid GIC specimens. EDX analysis at the junction estimated: Calcium and Phosphorus of the glass hybrid GIC showed insignificantly higher mean valued than that of the bioactive GIC. Silica and Aluminum mean values at the junction were significantly higher with bioactive GIC specimens than glass hybrid GIC specimen. Micro-raman spectroscopy revealed that bioactive GIC specimens showed higher frequencies of v 1 PO 4, which indicated high level of remineralization. CONCLUSIONS: It was concluded that ion-releasing bioactive resin-based restorative material had increased the microhardness and remineralization rate of carries affected and sound dentin. In addition, enzymatic caries excavation with papain-based CMCR agent has no adverse effect on dentin substrate.

Effect of phosphate group on remineralization of early enamel caries regulated by amelogenin peptide.

OBJECTIVE: To show the effect of the phosphate group on the remineralization process of early enamel caries mediated by amelogenin peptide. METHODS: Freshly extracted, completed, and crack-free bovine teeth were used to create artificial early enamel caries, which were randomly divided into four groups: Group A: fluorination remineralized solution treatment group; Group B: pure remineralized solution treatment group. Group C: 100 g/ml recombinant Amelogenin peptide remineralized solution treatment group (with single phosphate group on N-terminus); Group D: 100 g/ml non-phosphorylated recombinant Amelogenin peptide remineralized solution treatment group (without single phosphate group on N-terminus). For 12 days, fresh remineralized solutions were replaced daily. Transverse microradiography (TMR) was used after remineralization to determine mineral loss and demineralization depth before and after each sample's remineralization. Each sample's depth of remineralization and mineral acquisition were then determined. RESULTS: The recombinant amelogenin peptide group significantly outperformed the non-phosphorylated amelogenin peptide group in terms of mineral acquisition and mineralization depth (P<0.05). CONCLUSIONS: The recombinant Amelogenin's solitary phosphate group at the N-terminus helps recombinant Amelogenin to encourage the remineralization process of early enamel caries.

Enamel remineralisation prospect of Moringa Oleifera hydrogel, eggshell hydrogel versus sodium fluoride varnish on artificially demineralised primary teeth: in vitro study.

PURPOSE: The purpose of the present in vitro study is to investigate and compare the remineralising potential of Moringa Oleifera extract, eggshell, and sodium fluoride varnish on microhardness of artificially demineralised enamel of primary teeth with biomimetic minimally invasive approach following the world paradigm shift towards natural products in paediatric dentistry. MATERIAL AND METHODS: Sample size included 44 primary molars. The mineral content and surface microhardness of all specimens were initially assessed using energy dispersive x-ray examination (EDX) and Vickers microhardness. The specimens were artificially demineralised for 96 h at a temperature of 37°C and then reassessed directly after demineralisation. The demineralised enamel specimens were randomly divided into four groups according to the remineralisation regimen utilised. Group 1: Artificial saliva (control); Group 2: Sodium fluoride varnish; Group 3: Eggshell hydrogel; and Group 4: Moringa Oleifera hydrogel. The specimens were stored for 8 days and then subsequently evaluated using EDX and microhardness assessment by Vickers microhardness test and scanning electron microscope (SEM).  Results: Regarding the microhardness test, there was a significant difference between the Moringa Oleifera group and Eggshell group compared to fluoride varnish (p < 0.05). Regarding EDX analysis, there was a statistically significant difference (p < 0.05) between Moringa Oleifera group and Eggshell group compared to fluoride varnish as the highest values were for Moringa Oleifera and Eggshell. On the other hand, there was no statistically significant difference (p > 0.05) between Moringa Oleifera and Eggshell in both the measurements. CONCLUSION: Moringa Oleifera and Eggshell might be considered as a biomimetic natural material capable of guiding enamel tissue remineralisation in early carious lesion of primary teeth. CLINICAL RELEVANCE: This research demonstrated the capability for early enamel caries to be remineralised using novel materials with a naturally counterpart implicated in biomineralisation as proved to be more effective than traditionally used fluoride varnish in primary teeth.

Inhibition of incipient caries lesion progression by different fluoridated varnishes.

The aim of this in vitro study was to evaluate the potential of different fluoridated varnishes to inhibit the progression of incipient caries lesions after cariogenic challenge. Seventy-five enamel specimens of bovine teeth were prepared and selected based on the initial surface microhardness (SMH). The specimens were first subjected to artificial demineralization (in buffer solution) after which SMH was re-analyzed (SM1). They were then randomly assigned to five experimental groups: 1- CONTROL (pH cycling), 2 - MI VAR (MI Varnish with RECALDENTTM - CPP-ACP), 3 - PROFL (Profluorid®), 4 - CLIN (ClinproTM White Varnish with TCP), and 5 - DUR (Duraphat®) (n=15). The varnishes were applied in a thin layer and the specimens were then subjected to pH cycling for eight days. The SMH and cross-sectional microhardness (CSMH) were then analyzed (SM2). The fluoride and calcium ion concentrations in the solution were analyzed by the indirect method and atomic absorption spectrophotometry, respectively. Data were statistically analyzed by Student's t-test, ANOVA/Tukey-Kramer, or Kruskall-Wallis/Dunn tests for individual comparisons (p˂0.05). All varnishes led to significantly higher surface and subsurface remineralization compared with the control group but did not differ from each other. The varnishes with the highest fluoride release were: PROFL and CLIN, followed by MI VAR and DUR. The varnishes with significantly higher release of calcium were: DUR, CLIN, and PROFL. In conclusion, all commercial fluoridated varnishes tested have good potential to inhibit the progression of demineralization, regardless of the ion release mechanisms.

Evaluation of toothpastes for treating root carious lesions - a laboratory-based pilot study.

BACKGROUND: Root caries is preventable and can be arrested at any stage of disease development. The aim of this study was to investigate the potential mineral exchange and fluorapatite formation within artificial root carious lesions (ARCLs) using different toothpastes containing 5,000 ppm F, 1,450 ppm F or bioactive glass (BG) with 540 ppm F. MATERIALS AND METHODS: The crowns of each extracted sound tooth were removed. The remaining roots were divided into four parts (n = 12). Each sample was randomly allocated into one of four groups: Group 1 (Deionised water); Group 2 (BG with 540 ppm F); Group 3 (1,450 ppm F) and Group 4 (5,000 ppm F). ARCLs were developed using demineralisation solution (pH 4.8). The samples were then pH-cycled in 13 days using demineralisation solution (6 h) and remineralisation solution (pH 7) (16 h). Standard tooth brushing was carried out twice a day with the assigned toothpaste. X-ray Microtomography (XMT) was performed for each sample at baseline, following ARCL formation and after 13-day pH-cycling. Scanning Electron Microscope (SEM) and 19F Magic angle spinning nuclear magnetic resonance (19F-MAS-NMR) were also performed. RESULTS: XMT results showed that the highest mineral content increase (mean ± SD) was Group 4 (0.09 ± 0.05), whilst the mineral content decreased in Group 1 (-0.08 ± 0.06) after 13-day pH-cycling, however there was evidence of mineral loss within the subsurface for Groups 1, 3 and 4 (p < 0.05). SEM scans showed that mineral contents within the surface of dentine tubules were high in comparison to the subsurface in all toothpaste groups. There was evidence of dentine tubules being either partially or completely occluded in toothpaste groups. 19F-MAS-NMR showed peaks between - 103 and - 104ppm corresponding to fluorapatite formation in Groups 3 and 4. CONCLUSION: Within the limitation of this laboratory-based study, all toothpastes were potentially effective to increase the mineral density of artificial root caries on the surface, however there was evidence of mineral loss within the subsurface for Groups 1, 3 and 4.

Comparison of the effects of fluoride varnish containing silver nanoparticles and conventional fluoride varnish on the surface microhardness of tooth enamel.

BACKGROUND: Nano-silver fluoride (NSF) has been introduced to improve enamel lesions. The effective use of varnishes is important in the prevention of dental caries. OBJECTIVES: The study aimed to compare the effect of conventional sodium fluoride varnish with the same varnish containing 1% and 2% silver nanoparticles (AgNP) on the surface microhardness of enamel. MATERIAL AND METHODS: The baseline surface microhardness of 40 premolar teeth was measured using a Vickers microhardness tester. After immersing the samples in a demineralizing agent for 24 h, the microhardness was measured again. In group B, a layer of conventional fluoride varnish was applied to the tooth surfaces using a microbrush with soft bristles, following the manufacturer's instructions. Groups C and D were treated with 1% and 2% NSF varnishes, respectively, while group A received no varnish. Surface microhardness tests were conducted on all specimens, including those previously tested. RESULTS: The microhardness of the enamel surface increased significantly in all 3 test groups compared to the microhardness after demineralization (p < 0.05). CONCLUSIONS: Conventional fluoride varnish and fluoride varnishes containing 1% and 2% AgNP are equally effective in remineralizing initial caries.

Effect of strontium fluoride on mechanical and remineralization properties of enamel: An in-vitro study on a modified orthodontic adhesive.

OBJECTIVES: Evaluate the ability of strontium fluoride on bond strength and enamel integrity after incorporation within orthodontic adhesive system as a delivery vehicle. METHODS: Experimental orthodontic adhesive system Transbond™ XT were modified with 1% Sr2+, 0.5% SrF2, 1% strontium, 0.5% Sr2+, 1% F-, 0.5% F-, and no additions were control. Mixing of formulation was monitored using Fourier transform infrared spectroscopy. Small-molecule drug-discovery suite was used to gain insights into Sr2+, F-, and SrF2 binding. Shear bond testing was performed after 6-months of ageing. Enamel blocks were cut, and STEM pictures were recorded. Specimens were indented to evaluate elastic modulus. Raman microscope was used to collect Raman spectra and inspected using a scanning electron microscope. Crystal structural analysis was performed using X-ray diffraction. Effect of material on cellular proliferation was determined. Confocal was performed to evaluate the effect of formulation on biofilms. RESULTS: FTIR of modified adhesives depicted peak changes within range due to various functional groups existing within samples. TEM represented structurally optimized hexagonal unit-cell of hydroxyapatite. Mean shear bond strength is recorded highest for Transbond XT with 1% SrF2. Dead bacterial percentage appeared higher in 0.5% SrF2 and 1% F- specimens. Crystal lengths showed an increase in 0.5% and 1% SrF2 specimens. Phase contrast within TEM images showed a union of 0.5% SrF2 crystal with enamel crystal with higher elastic modulus and highly mineralized crystalline hydroxyapatite. Intensity of ν1 PO43- and ν1 CO32- along with carbonate - / ν1PO43- ratio displayed good association with strontium fluoride. The formulation showed acceptable cell biocompatibility (p < 0.353). All specimens displayed characteristic diffraction maxima of different apatite angles within XRD. SIGNIFICANCE: Experimental results suggested good biocompatibility, adequate mechanical strength, and far-ranging crystallization ability. This would provide a new strategy to overcome the two major challenges of fixed orthodontics, biofilm growth, and demineralization of enamel.

Remineralizing effect of the association of nano-hydroxyapatite and fluoride in the treatment of initial lesions of the enamel: A systematic review.

OBJECTIVE: Assessed the effect of dental products containing nano-hydroxyapatite (nano-HA) + fluoride on the remineralization of white spot lesions (WSL) in vivo or in situ. METHODS: Seven databases were explored using a two-pronged approach (intervention/treatment). After screening, full-text assessment, and further exclusion, the qualitative synthesis of five studies (four clinical and one in situ) was performed. Based on the Cochrane collaboration guidelines relevant data of the studies were collected and summarized. The Cochrane risk of bias tool for randomized trials (RoB 2.0) was used to appraise the studies' methodological quality and the GRADE guidelines to assess their level of evidence. The RoB 2.0 domains were rated on their risk of bias (RoB) as low, high, or with some concerns, and an adaptation of the tool was used to the in situ study. RESULTS: The included studies assessed 151 WSL in anterior permanent teeth, on patients with varying ages. The protocol application, treatment length (7d-12 w), and control groups varied greatly between the studies making the performance of a quantitative analysis unfeasible. The general RoB of the clinical studies was classified as being of low risk (n = 2) or some concerns (n = 2). The in situ study was considered as being of low risk. The level of the evidence was moderate. Most of the studies found moderate evidence regarding the superiority of this association in clinical settings. CONCLUSION: Even with the nano-HA + fluoride promising results for the remineralization treatment of WSL, due to the restricted number of studies and types of products, its extended use cannot be recommended based on the current systematic review, especially when considering the moderate level of the evidence found. CLINICAL SIGNIFICANCE: Due to the biocompatibility and higher surface coverage of nano-HA and the remineralization capacity of fluoride formulations, the association of these elements to remineralize WSL has been positively reported. After the collection and qualitative appraise of the data, the clinical evidence of the use of these dental products is promising but limited.

Fluoride-amorphous calcium phosphate and biomimetic nano-hydroxyapatite for enamel remineralization: An in-vitro study of surface microhardness and composition.

AIM: Fluoride-Amorphous Calcium Phosphate and Biomimetic Nano-Hydroxyapatite for Enamel Remineralization; An In-Vitro Study of Surface Microhardness and Composition. MATERIAL AND METHODS: Ninety-six extracted human premolars with sound buccal surface were divided using a randomization computer-generating software into four groups; Group I (control) sound untreated enamel, Group II (demineralized) demineralized to create white spot lesions, Group III (biom-n-HA) demineralized and then treated with biomimetic nanohydroxyapatite cream, and Group IV (F-ACP) demineralized and then treated using Fluoride-Amorphous Calcium Phosphate varnish. Each group was divided into two subgroups; subgroup "A" evaluated for mineral content using energy dispersive x-ray spectroscopy (EDX) and for surface microhardness using the Vickers microhardness test and Subgroup "B" evaluated for white spot lesion depth using a polarized light microscope (PLM). RESULTS: The highest microhardness (VHN) was found in the (F-ACP) group (mean=428.61±54.43) and then in the (Biom-n-HA) group (mean=408.11±70.16) followed by the (Control) group (mean=402.13±53.40) with no significant difference between them and finally in the significantly different (Demineralized) group (mean=256.99±45.83). The weight percentage of Ca (30.29±1.04 and 33.44±1.07) and Ca/P ratio (1.87±0.06 and 2.03±0.05) were significantly different between Group III and Group IV respectively. PLM measurements in Group II (198.83µm), Group III (60.17µm), and Group IV (26.33µm) were significantly different. CONCLUSIONS: Both the (Biom-n-HA) cream and the (F-ACP) varnish showed promising results for enamel remineralization. The increased enamel surface microhardness was consistent with the mineral content and the changes in the birefringence.

Amelogenin-inspired peptide, calcium phosphate solution, fluoride and their synergistic effect on enamel biomimetic remineralization: an in vitro pH-cycling model.

BACKGROUND: Several methods were introduced for enamel biomimetic remineralization that utilize a biomimetic analogue to interact and absorb bioavailable calcium and phosphate ions and induce crystal nucleation on demineralized enamel. Amelogenin is the most predominant enamel matrix protein that is involved in enamel biomineralization. It plays a major role in developing the enamel's hierarchical microstructure. Therefore, this study was conducted to evaluate the ability of an amelogenin-inspired peptide to promote the remineralization potential of fluoride and a supersaturated calcium phosphate solution in treating artificially induced enamel carious lesions under pH-cycling regimen. METHODS: Fifty enamel slices were prepared with a window (4*4 mm2 ) on the surface. Five samples were set as control healthy enamel and 45 samples were subjected to demineralization for 3 days. Another 5 samples were set as control demineralized enamel and 40 enamel samples were assigned into 8 experimental groups (n=5) (P/I, P/II, P/III, P/AS, NP/I, NP/II, NP/III and NP/AS) according to peptide treatment (peptide P or non-peptide NP) and remineralizing solution used (I; calcium phosphate solution, II; calcium phosphate fluoride solution, III; fluoride solution and AS; artificial saliva). Samples were then subjected to demineralization/remineralization cycles for 9 days. Samples in all experimental groups were evaluated using Raman spectroscopy for mineral content recovery percentage, microhardness and nanoindentation as healthy, demineralized enamel and after pH-cycling. Data were statistically analysed using two-way repeated measures Anova followed by Bonferroni-corrected post hoc test for pairwise multiple comparisons between groups. Statistical significance was set at p= 0.05. Additionally, XRD, FESEM and EDXS were used for crystal orientation, surface morphology and elemental analysis after pH-cycling. RESULTS: Nanocrystals clumped in a directional manner were detected in peptide-treated groups. P/II showed the highest significant mean values in mineral content recovery (63.31%), microhardness (268.81±6.52 VHN), elastic modulus (88.74±2.71 GPa), nanohardness (3.08±0.59 GPa) and the best crystal orientation with I002/I300 (1.87±0.08). CONCLUSION: Despite pH changes, the tested peptide was capable of remineralizing enamel with ordered crystals. Moreover, the supplementary use of calcium phosphate fluoride solution with peptide granted an enhancement in enamel mechanical properties after remineralization.

Remineralisation of enamel and dentine with stabilised stannous fluoride dentifrices in a randomised cross-over in situ trial.

OBJECTIVES: To compare the remineralisation efficacy and ion bioavailability of two novel SnF2-containing dentifrices in a blinded, cross-over, randomised in situ clinical study. METHODS: Six participants wore removal palatal appliances holding human enamel and dentine blocks with subsurface lesions. Appliances were worn for two treatment periods of 14 consecutive days each, with a one-week washout period in-between. Participants were randomly allocated to rinse with a 1:5 diluted coded slurry of one of two dentifrices containing either 5 % casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) +1100 ppm F as SnF2 [MIPOP], or 1100 ppm F as SnF2 [CT], for 1 min, four times a day. Saliva was collected post-treatment and analysed for tin, calcium, inorganic phosphate and fluoride ions using atomic absorption spectrophotometry and ion chromatography. Enamel and dentine lesions were analysed for percent remineralisation (%R) using transverse microradiography and percent surface microhardness recovery (%SMHR). RESULTS: MIPOP released significantly higher F (3.00 ± 0.27 mM), Ca (15.23 ± 3.23 mM) and Sn (1.18 ± 0.13 mM) into saliva whereas CT released 2.89 ± 0.32 mM F and only 0.84 ± 0.11 mM Ca and 0.28 ± 0.10 mM Sn. MIPOP produced significantly higher %R than CT: 25.6 ± 1.5 % compared to 15.2 ± 0.7 % in enamel, and 33.6 ± 3.1 % compared to 20.6 ± 1.1 % in dentine. Additionally, MIPOP produced significantly higher %SMHR (18.2 ± 7.9 %) compared to CT (4.1 ± 0.6 %). CONCLUSIONS: Both dentifrices promoted remineralisation, but the MIPOP dentifrice with added CPP-ACP and the ion-stabilising effects of CPP released higher amounts of bioavailable tin and produced significantly higher remineralisation and surface microhardness recovery. CLINICAL SIGNIFICANCE: Modern dentifrices contain SnF2 for a range of oral health benefits. Challenges associated with stability of these formulations can affect ion bioavailability, reducing efficacy. Two dentifrices with SnF2 promoted remineralisation in situ, however the dentifrice with the added saliva biomimetic CPP-ACP was superior and therefore may produce greater health benefits.

Xylitol associated or not with fluoride: Is the action the same on de- and remineralization?

OBJECTIVES: This study evaluated the effect of xylitol combined or not with fluoride (F) on reduction of demineralization and increase of remineralization of shallow and deep artificial enamel lesions. METHODS: Bovine enamel samples were allocated to the following solutions groups: no xylitol (negative control), 5% xylitol, 10% xylitol, 20% xylitol, 500 ppm F (as NaF), 5% xylitol+F, 10% xylitol+F or 20% xylitol+F (n = 12-15). For the demin study, a pH-cycling model (demineralization-6 h, pH 4.7/remineralization 18 h, pH 7.0) was employed for 7 days. Treatments were applied 2 × 1 min. In the remin study, specimens were pre-demineralized for 2, 5 or 10 days. Afterwards, a pH-cycling protocol was conducted (2 h demineralizing and 22 h remineralizing solution/day for 8 days) and the same treatments were done. The response variables were percentage surface hardness loss (%SHL) and transverse microradiography. Data were analyzed by RM ANOVA/Tukey or Kruskal-Wallis/Dunn (p < 0.05) RESULTS: F and Xylitol combined with F reduced the %SHL (23-30%) compared to the negative control (61.5%). The integrated mineral loss and the lesion depth were not reduced by any treatment. Surface hardness recovery was seen only for shallow lesions in case of 20% xylitol+F compared to negative control. No lesion depth recovery, but significant mineral recovery was seen for F (2-days and 10-days lesion). CONCLUSIONS: All concentrations of xylitol+F reduced enamel surface demineralization, while only 20% xylitol+F improved surface remineralization of shallow lesions in vitro. CLINICAL SIGNIFICANCE: Our results suggest that while F or any concentration of xylitol + F reduces surface demineralization, only 20% xylitol+F improves surface remineralization of shallow lesions in vitro. Therefore, xylitol may be added into oral products, combined to F, to control dental caries.

Remineralizing effects of hydroxypropyl methylcellulose film-loaded amorphous calcium phosphate nanoprecursors on enamel artificial caries lesions.

OBJECTIVES: This study was to investigate hydroxypropyl methylcellulose (HPMC) film as a carrier for amorphous fluorinated calcium phosphate (AFCP) nanoprecursors to continuously deliver biomimetic remineralization of enamel artificial caries lesions (ACL). MATERIALS AND METHODS: The AFCP/HPMC films were comprised of 25 wt% AFCP nanoparticles and 75 wt% HPMC. They were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and biocompatibility tests. Forty enamel ACL were prepared and randomly divided into four groups (n = 10): The enamel surfaces were covered with a pure HPMC film, Tooth Mousse Plus (contains 10% CPP-ACP and 0.2% NaF), and AFCP/HPMC film, or without any things (serving as negative control). Subsequently, all samples were alternatively kept in artificial saliva and a modified pH-cycling before they were characterized by Micro-CT, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflectance (ATR)-FTIR, XRD, and nanoindentation. RESULTS: After the enamel ACL was challenged by pH cycling, Tooth Mousse Plus and AFCP/HPMC film groups exhibited less lesion depth and mineral loss than the negative control and pure HPMC film groups. Additionally, the AFCP/HPMC film group revealed a highest remineralization rate of 55.34 ± 3.10 % among the all groups (p < 0.001). The SEM findings showed that the enamel ACL were densely deposited with minerals in the AFCP/HPMC film group, and the EDX results suggested a higher content of fluorine in the remineralized tissues. In particular, the AFCP/HPMC film group exhibited the best nanomechanical performance after 2 weeks of pH cycling (p < 0.05), with the hardness (H) restored from 0.29 ± 0.19 to 2.69 ± 0.70 GPa, and elastic modulus (Er) restored from 10.77 ± 5.30 to 68.83 ± 12.72 GPa. CONCLUSION: The AFCP/HPMC film might be used as a promising strategy for arresting or reversing incipient enamel caries lesions.

An in vitro evaluation of the effects of fluoride, CPP-ACP, or resin infiltration on discoloration caused by pediatric supplements.

OBJECTIVES: White spot lesions are more susceptible to staining agents due to their porous structure. This study examines the impact of white spot lesion treatments on discoloration caused by pediatric supplements. METHOD AND MATERIALS: Three treatments (fluoride, casein phosphopeptide-amorphous calcium phosphate [CPP-ACP], resin infiltration), a control, and their respective syrup-based subgroups (iron and black elderberry syrups) were established, each with eight teeth. Artificial white spot lesions were induced, and weekly applications of fluoride varnish, daily applications of CPP-ACP paste, or a single resin infiltration procedure were performed on the white spot lesions within the treatment groups over 4 weeks. Simultaneously, samples were exposed daily to iron or black elderberry syrups. Spectrophotometer measurements were taken at baseline, after demineralization (T0), and after 1 (T1), 2 (T2), and 4 weeks (T4). ΔE00 values were calculated. Statistical analysis was conducted using a three-way mixed-design ANOVA, with the significance level set at P = .05. RESULTS: At T4, ΔE00 values from all groups exceeded the clinical acceptability limit of 1.8. At T2 and T4, the ΔE00 values obtained from the black elderberry syrup subgroups were significantly higher (P < .001). At T4, the highest ΔE00 values were seen in the CPP-ACP groups (P < .001). The lowest ΔE00 values at T2 and T4 were observed in the resin infiltration groups (P < .05). CONCLUSIONS: Supplements containing ferrous sulfate and black elderberry extract caused color changes in white spot lesions that exceeded the clinical acceptability limit. Resin infiltration of white spot lesions provides advantages over remineralization treatments, particularly in minimizing discoloration induced by pediatric supplements.

Effect of calcium-coacervate infiltration of artificial enamel caries lesions in de- and remineralizing conditions.

OBJECTIVES: Calcium-coacervate emulsions (CC) might be considered as mineral precursors to foster remineralization of carious dental hard tissues. This study analyzed the instant effect of repeated infiltration of artificial caries lesions with a CC emulsion as well as the effects of subsequent exposure of CC-infiltrated lesions to demineralizing and remineralizing environments. METHODS: Bovine enamel specimens were partly covered with varnish to leave three exposed windows. Artificial enamel caries lesions were created (pH 4.95, 17d). Baseline controls (BL) were obtained by preparing a thin section of each specimen. Specimens were allocated to five groups. In three groups lesions were etched with 37 % phosphoric acid gel, infiltrated with dipotassium hydrogen phosphate and subsequently with a calcium coacervate emulsion, prepared by mixing CaCl2 ⋅ 2H2O with polyacrylic acid sodium salt (PAA-Na). Subsequently, the infiltration effect was either analyzed immediately (Inf.) or after exposition to either de- (Inf.+DS) or remineralizing solution (Inf.+RS) for 10 or 20 days, respectively. In two control groups specimens were exposed to either DS or RS, respectively without prior CC infiltration. Integrated mineral loss [ΔZ(vol%×µm)] was analyzed using transverse microradiography (TMR). RESULTS: Infiltration of enamel caries lesions with coacervate solution resulted in only subtle immediate mineral gain even if repeated. When exposed to demineralizing conditions, infiltrated lesions showed significantly less mineral loss compared to untreated controls (p < 0.05; Kruskal Wallis) and exhibited characteristic mineral depositions within the lesion body. CONCLUSIONS: While immediate mineral gain by infiltration was only modest, the CC-emulsion might be able to prevent demineralization in acidic conditions. CLINICAL SIGNIFICANCE: Calcium coacervates might act protective against further demineralization when infiltrated into enamel caries lesions.

Ultrastructural investigation of the effect of toothpastes containing different remineralizing agents on demineralized enamel.

OBJECTIVE: The present study aimed to evaluate the effect of remineralizing agents on demineralized enamel intended for use as fluoride substitutes or supplements for oral hygiene applications. METHODOLOGY: Enamel samples were obtained from 30 bovine teeth. The enamel blocks were stored in 20 mL of demineralization solution for 72 h. They were then brushed with the following toothpaste for the remineralization protocol: NaF, NaF/SnF2 combination, NovaMin, or nano-hydroxyapatite. SEM/EDX examinations and microhardness measurements of the samples were performed to investigate the remineralization efficacy of the studied toothpaste. One-way analysis of variance (ANOVA) with post hoc Tukey's HSD test was used to analyze the change in microhardness values in different remineralization protocols (p < 0.05). RESULTS: Differences in the mean remineralization (%RP) and hardness recovery (%HR) were determined between the groups (p < 0.05). Groups 1 and 4 showed significant differences in %RP (p < 0.05). In the SEM/EDX examinations, the samples treated with n-HAp showed an accumulation of crystal deposits on the enamel surface, although at a lower density than those treated with NaF and NaF/SnF2 combination. CONCLUSION: The remineralization strategy in toothpaste plays an important role in enamel remineralization. NovaMin-containing toothpaste showed positive effects on the enamel surface with better Ca/P ratio. Toothpastes containing n-HAp triggered less change in the increase of microhardness values compared to other toothpastes. The use of SnF2 in toothpaste in combination with NaF significantly increased the binding of fluoride to demineralized enamel compared to toothpaste containing NaF alone.

A Comparison of the Enamel Remineralisation Potential of Self-Assembling Peptides.

BACKGROUND: The aim of this research was to compare the efficacy of the remineralising potential of self-assembling peptides (SAPs): Curodont Repair (P11-4), P26, and leucine-rich amelogenin peptides (LRAP) with the standard 5% NaF varnish (Duraphat) on early enamel caries lesions (EECLs). METHODS: A demineralising solution (DS) was used to create artificial EECLs in human dental enamel specimens, which were randomly allocated to treatment groups: P11-4; P26 solution; LRAP solution; 5% NaF varnish; and deionised water (DIW). Each specimen was subjected to 8 days of pH cycling. Specimens from each test group were subjected to microcomputed tomography (micro-CT) and nanomechanical testing to assess mineral density (MD), hardness (H), and elastic modulus (EM) properties of sound, demineralised, and treated enamel. RESULTS: The mean MD percentage gain was highest in the P26 and P11-4 groups, followed by the LRAP, 5% NaF varnish, and DIW groups. There were statistically significant differences amongst groups. In the outer layer of EECLs, the EM and H were highest in P26 and P11-4 groups, followed by the LRAP and 5% NaF varnish. In the inner layer of EECLs, the EM and H were highest in P11-4 and P26 groups, indicative of enhanced penetration and remineralisation of the deeper parts of the artificial EECLs. CONCLUSIONS: P26 and P11-4 SAPs are more effective than 5% NaF varnish in remineralising the depth of EECLs.

Combined Casein Phosphopeptide-Amorphous Calcium Phosphate and Fluoride Is Not Superior to Fluoride Alone in Early Carious Lesions: A Meta-Analysis.

There is a growing need for effective methods in the management of early stage carious lesions. Therefore, the aim of this study was to evaluate the effect of combined casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride on white spot lesions (WSLs) compared to fluoride-only interventions. This meta-analysis was performed according to PRISMA guidelines and registered in PROSPERO (CRD42021286245). The Medline, Embase, and Cochrane Central databases were searched until October 17, 2022. Eligible studies were randomized controlled trials. Outcome variables included laser fluorescence (LF), quantitative light-induced fluorescence (QLF), and lesion area scores. The random-effects model was used for analysis, and results were given as standardized mean difference (SMD) and mean difference (MD) with a 95% confidence interval. Risk of bias was assessed using the RoB 2 tool, and the level of evidence with GRADE. Our systematic search yielded 973 records after duplicate removal, 21 studies were included for qualitative synthesis, and 15 studies were eligible for quantitative analysis. No significant difference was found between CPP-ACP and fluoride versus fluoride alone in LF at 1, 3, and 6 months of use: SMD -0.30 (-0.64; 0.04); SMD -0.47 (-1.02; 0.07); SMD -0.49 (-1.13; 0.15), respectively. For QLF, the analysis did not demonstrate significant differences between these two kinds of treatment at 1 and 6 months of use: MD 0.21 (-0.30;0.71); MD 0.60 (-1.70;2.90), but at 3 months, higher QLF values were found in the fluoride-only group compared to the CPP-ACP and fluoride combination was shown regarding the WSLs: MD 0.58 (0.25;0.91). On the contrary, data showed a small but statistically significant decrease in the lesion area in favor of the CPP-ACP plus fluoride versus fluoride alone at 6 months MD -0.38 (-0.72; -0.04). None of these observed changes indicated substantial clinical relevance. The combination of CPP-ACP and fluoride did not overcome the effect of fluoride given alone. Our data suggest that fluoride itself is effective in improving WSLs. However, the certainty of evidence was very low. These results indicate that further studies and future development of more effective products than CPP-ACP are needed in addition to fluoride to achieve robust amelioration of WSLs.

In vitro caries-preventive effect of a mineralization-promoting peptide combined with fluoride gel on sound primary teeth.

BACKGROUND: Mineralization-promoting peptide-3 (MPP3) is a new biomimetic remineralization agent. AIM: To assess the remineralization efficiency of MPP3, either alone or in combination with fluoride gel. DESIGN: The samples were divided into four groups: control, 1.23% fluoride gel, 10% MPP3 gel, and 1.23% fluoride gel + 10% MPP3. Following the application of remineralization agents (4 min), the samples remained in a pH-cycling model (37°C, 4 weeks). Microhardness, microcomputed tomography (micro-CT), polarized light microscopy (PLM), and field emission scanning electron microscopy (FE-SEM) analysis were conducted. RM-ANOVA, one-way ANOVA, and intraclass correlation coefficient (ICC) were used for statistical analysis, and a significance level of p < .05 was employed. RESULTS: Mineralization-promoting peptide 3 and fluoride gel + MPP3 increased the microhardness of the enamel compared with initial values in each group (p < .05). Mineralization-promoting peptide 3 successfully maintained the mineral density of enamel, although the cariogenic pH-cycling and PLM results indicated that the lesion depth (µm) was significantly lower in the fluoride gel + MPP3 group (27.0336 ± 12.53650) than in the control group (37.3907 ± 12.76002, p < .05). CONCLUSION: The combined use of MPP3 with fluoride gel enhanced the caries-protective and mineralization-promoting effects of fluoride. Mineralization-promoting peptide 3 may be a potential agent that can be employed to improve the physical properties of enamel.