Atherogenic Indices as a Predictor of Aortic Calcification in Prostate Cancer Patients Assessed Using 18F-Sodium Fluoride PET/CT

A major pathophysiological cause of cardiovascular disease is vascular plaque calcification. Fluorine 18−Sodium Fluoride (18F-NaF) PET/CT can be used as a sensitive imaging modality for detection of vascular calcification. The aim of this study was to find a non-invasive, cost-efficient, and readily available metric for predicting vascular calcification severity. This retrospective study was performed on 36 participants who underwent 18F-NaF fused PET/CT scans. The mean standard uptake values (SUVs) were calculated from manually sectioned axial sections over the aortic arch and thoracic aorta. Correlation analyses were performed between SUVs and calculated atherogenic indices (AIs). Castelli’s Risk Index I (r = 0.63, p < 0.0001), Castelli’s Risk Index II (r = 0.64, p < 0.0001), Atherogenic Coefficient (r = 0.63, p < 0.0001), Atherogenic Index of Plasma (r = 0.51, p = 0.00152), and standalone high-density lipoprotein (HDL) cholesterol (r = −0.53, p = 0.000786) were associated with aortic calcification. AIs show strong association with aortic arch and thoracic aorta calcifications. AIs are better predictors of vascular calcification compared to standalone lipid metrics, with the exception of HDL cholesterol. Clinical application of AIs provides a holistic metric beneficial for enhancing screening and treatment protocols.

Simultaneous assessment of microcalcifications and morphological criteria of vulnerability in carotid artery plaque using hybrid 18F-NaF PET/MRI

BACKGROUND

Previous studies have suggested the role of microcalcifications in plaque vulnerability. This exploratory study sought to assess the potential of hybrid positron-emission tomography (PET)/magnetic resonance imaging (MRI) using 18F-sodium fluoride (18F-NaF) to check simultaneously 18F-NaF uptake, a marker of microcalcifications, and morphological criteria of vulnerability.

METHODS AND RESULTS

We included 12 patients with either recently symptomatic or asymptomatic carotid stenosis. All patients underwent 18F-NaF PET/MRI. 18F-NaF target-to-background ratio (TBR) was measured in culprit and nonculprit (including contralateral plaques of symptomatic patients) plaques as well as in other arterial walls. Morphological criteria of vulnerability were assessed on MRI. Mineral metabolism markers were also collected. 18F-NaF uptake was higher in culprit compared to nonculprit plaques (median TBR 2.6 [2.2-2.8] vs 1.7 [1.3-2.2]; P = 0.03) but was not associated with morphological criteria of vulnerability on MRI. We found a positive correlation between 18F-NaF uptake and calcium plaque volume and ratio but not with circulating tissue-nonspecific alkaline phosphatase (TNAP) activity and inorganic pyrophosphate (PPi) levels. 18F-NaF uptake in the other arterial walls did not differ between symptomatic and asymptomatic patients.

CONCLUSIONS

18F-NaF PET/MRI may be a promising tool for providing additional insights into the plaque vulnerability.

[Fluorides in water for consumption in northern and western Mexico]

The amount of fluoride in water in some regions of Mexico represents a public health problem. The aim of this study was to conduct a systematic review of original studies that report fluoride levels in tap and bottled water from the northern and western regions of Mexico. A systematic review was conducted using the PRISMA method in PubMed, Scopus, Medigraphic and Scielo databases. The keywords fluoride OR fluorosis AND water AND Mexico were used for the search and the records found were included and excluded according to the previous established criteria. We reviewed data in articles published between January 1st, 2010 and March 30th, 2021. We identified a total of 36 records. Most showed data found in the western region (n = 23), while the rest reported data found in the north. Both regions reported maximum and mean sample ranges above those suggested by the World Health Organization and national regulations. According to the analyzed data, in Mexico, the northern and western regions of the country show a concerning situation due to the high levels of fluoride reported by many authors in tap and bottled water. Almost all authors reported data above those recommended for national and international regulations, which represent an important public health problem that requires attention.

Effectiveness of CPP-ACP and Fluoride Products in Tooth Remineralization

OBJECTIVES

To compare the effectiveness of the casein phosphopeptide-stabilized amorphous calcium phosphate (CPP-ACP) in the in situ remineralization of enamel exposed to two different degrees of preformed enamel lesions.

METHODS

One hundred and sixty 3x3x2 mm human enamel slabs were demineralized and divided into two subgroups according to baseline surface hardness (SH=B1≤150 and B2 >150). During each of four 10-day experimental periods, 10 participants wore intraoral removable acrylic palatal expanders with four human enamel slabs with preformed lesions (B1 and B2): CO1 and CO2 - Control: silica dentifrice without fluoride; MP1 and MP2: MI Paste; MPP1 and MPP2: MI Paste Plus; and FD1 and FD2: Fluoride dentifrice. The Knoop hardness test (50/15s Micromet 2001, Buehler, IL, USA) was performed after demineralization (B1 and B2) and after treatment (T1 and T2).

RESULTS

SH was higher in all treatment groups when compared with the controls, except for CO2 (Mann Whitney Wilcoxon Test; p <0.05). %SH was similar between MPP2 and FD2 and between MPP2 and MP2; however, FD2 and MPP2 products were more effective in microhardness recovery. In B1, all treatment groups were similar.

CONCLUSION

MPP and FD are more effective in preventing demineralization in enamel subsurface lesions.

Cytotoxicity of the Ingredients of Commonly Used Toothpastes and Mouthwashes on Human Gingival Fibroblasts

Objectives:

Toothpastes and mouthwashes contain ingredients that may be toxic for oral mucosal tissues. This study aimed to assess the cytotoxicity of the ingredients of commonly used toothpastes and mouthwashes.

Materials and Methods:

This experimental study was performed on 16 toothpastes and four mouthwashes widely available in the Iranian market. First, the concentration of six main ingredients of these products, namely sodium fluoride (NaF), sodium lauryl sulfate, cocamidopropyl betaine, zinc lactate, paraben, and sodium benzoate, was determined. The methyl thiazolyl tetrazolium (MTT) assay was used to assess the cytotoxicity of these materials for human gingival fibroblasts (HGFs). The MTT assay was performed at 1, 15, and 30 minutes following exposure to five concentrations of each material in triplicate (according to the concentrations obtained in the isolation step). Data were analyzed using three-way analysis of variance (ANOVA).

Results:

The difference in the cytotoxicity of the materials was statistically significant (P<0.001). Cytotoxicity was time- and concentration-dependent; by an increase in the concentration of the materials, their cytotoxicity increased over time. The cytotoxicity of sodium lauryl sulfate and cocamidopropyl betaine was >90%. The cytotoxicity of NaF varied from 25% to 70%, and the cytotoxicity of all concentrations of zinc lactate and sodium benzoate was <50% for HGFs.

Conclusion:

To decrease the cytotoxic effects of toothpastes, sodium lauryl sulfate and cocamidopropyl betaine should be replaced with safer detergents, and the concentration of fluoride should be decreased to 400 parts per million (ppm). Alternatively, fluoride may be replaced with other antibacterial and cariostatic agents.

Comparison of Fluoride Ion Release from Fluoride Gel in Various Solvents

OBJECTIVE

The aim of this study was to determine the concentration of fluoride ions present in various solvent solutions and compare it to the label amount of fluoride concentration.

MATERIAL AND METHODS

The gel containing amine fluoride and sodium fluoride was compared to gel containing sodium fluoride only. The solvents used in this study were distilled water, redistilled water, tap water, 0.9% sodium chloride solution and the artificial saliva. The amount of fluoride ion (F^-) was determined by the use of fluoride ion-selective electrode. The ANOVA and the Post hoc Tukey's test were used. The significance level was α = 5%.

RESULTS

The differences between F^- ion release in various solvents were statistically significant (p < 0.05). The F^- ion concentrations measured in both gels' redistilled water solutions were higher than the label concentration. There was a significant difference in fluoride ion release in sodium fluoride only gel solutions. Fluoride ion release was significantly different in combined fluoride gel solutions.

CONCLUSIONS

Amine fluorides do not interact with other ions present in the solution, whereas F^- ion release from sodium fluoride alters when other ions are dissolved in the same solution. Amine fluorides deliver F^- ions for caries prevention more efficiently.

Delayed Tooth Replantation after Root Surface Treatment with Papain and Sodium Fluoride in Rats: A Histological and Histomorphometrical Evaluation

Introduction

The aim of this study was to examine the histological effect of papain and sodium fluoride in delayed replantation of rat incisor teeth on the repair process.

Methods and Materials

Forty upper incisors of Wistar rats were randomly assigned to four groups (n=10). In group I, the dental papilla and the pulp tissue of extracted teeth were removed before immediate replantation in their sockets. In the other groups, the extracted teeth were maintained in dry storage for 60 min and subjected to different root surface treatments. In group II, the teeth were immersed in 10% papain for 20 min, scrubbed with gauze soaked in saline for 1 min, and immersed in a 2% acidulated-phosphate sodium fluoride solution for 20 min. In group III, the teeth were immersed in saline for 20 min, scrubbed with gauze soaked in saline for 1 min, and immersed in a 2% acidulated-phosphate sodium fluoride solution for 20 min. In group IV, root surface treatment was not applied. The root canals were treated and filled with a calcium hydroxide paste and the teeth were replanted. The animals were euthanized after 60 days and anatomic specimens containing the teeth were subjected to routine histochemical processing and staining with hematoxylin and eosin. The Kruskal-Wallis test was used, followed by the Dunn's test for multiple comparisons.

Results

Groups I and II had less inflammatory root resorption and total area of root resorption (P<0.05) than groups III and IV respectively.

Conclusions

Based on this animal study, root surface treatment with papain and sodium fluoride in delayed tooth replantation showed greater efficacy in controlling inflammatory root resorption and may be a viable option for clinical application.

Effect of 0.05% Sodium Fluoride Mouthwash on Surface Roughness and Friction between Ceramic Brackets and Rhodium-Coated and Uncoated Stainless Steel Wires

Objectives:

This study aimed to assess the effect of 0.05% sodium fluoride (NaF) mouthwash on the surface roughness and friction between ceramic brackets and rhodium-coated (RC) and uncoated stainless steel (SS) wires.

Materials and Methods:

This experimental study was performed on 48 maxillary premolar ceramic brackets. Twenty-four pieces of RC-SS wires were used. Samples were divided into four groups. Groups 1 and 2 were immersed in artificial saliva, and groups 3 and 4 were immersed in a solution consisting of artificial saliva (9%) and mouthwash (91%). To assess surface roughness, images were obtained from the surface of wires and brackets with atomic force microscopy (AFM) and scanning electron microscopy (SEM) before and after the intervention. To assess friction, the wires were ligated into brackets, and friction was measured at a crosshead speed of 0.5 mm/minute using a universal testing machine. Data were analyzed using one-way analysis of variance (ANOVA) at the 0.05 significance level.

Results:

Friction during sliding in RC wires was significantly less than that in SS wires (P<0.05). Increase in the friction in SS wires by mouthwash was significantly greater compared to RC wires (P<0.05). Surface roughness coefficients of the wires before the intervention were not significantly different. The surface roughness of the wires significantly increased after the intervention and it was greater in SS wires than in RC wires (P<0.05).

Conclusion:

Considering the lower friction and surface roughness of SS-RC wires compared to SS wires, SS-RC wires may be a better alternative for use with ceramic brackets.

Fluoride Induces a Volume Reduction in CA1 Hippocampal Slices Via MAP Kinase Pathway Through Volume Regulated Anion Channels

Regulation of cell volume is an important aspect of cellular homeostasis during neural activity. This volume regulation is thought to be mediated by activation of specific transporters, aquaporin, and volume regulated anion channels (VRAC). In cultured astrocytes, it was reported that swelling-induced mitogen-activated protein (MAP) kinase activation is required to open VRAC, which are thought to be important in regulatory volume decrease and in the response of CNS to trauma and excitotoxicity. It has been also described that sodium fluoride (NaF), a recognized G-protein activator and protein phosphatase inhibitor, leads to a significant MAP kinase activation in endothelial cells. However, NaF's effect in volume regulation in the brain is not known yet. Here, we investigated the mechanism of NaF-induced volume change in rat and mouse hippocampal slices using intrinsic optical signal (IOS) recording, in which we measured relative changes in intracellular and extracellular volume as changes in light transmittance through brain slices. We found that NaF (1~5 mM) application induced a reduction in light transmittance (decreased volume) in CA1 hippocampus, which was completely reversed by MAP kinase inhibitor U0126 (10 µM). We also observed that NaF-induced volume reduction was blocked by anion channel blockers, suggesting that NaF-induced volume reduction could be mediated by VRAC. Overall, our results propose a novel molecular mechanism of NaF-induced volume reduction via MAP kinase signaling pathway by activation of VRAC.

Effect of Fluoride, Casein Phosphopeptide-Amorphous Calcium Phosphate and Casein Phosphopeptide-Amorphous Calcium Phosphate Fluoride on Enamel Surface Microhardness After Microabrasion: An in Vitro Study

OBJECTIVES

This study aimed to assess the effect of applying casein phosphopeptide- amorphous calcium phosphate (CPP-ACP) paste, casein phosphopeptide-amorphous calcium phosphate fluoride (CPP-ACPF) paste and sodium fluoride gel on surface microhardness of enamel after microabrasion.

MATERIALS AND METHODS

Thirty freshly extracted human premolars were selected. All samples were subjected to hardness indentations made with the Vickers hardness machine and the average value was recorded as the initial surface microhardness. The specimens were then randomly divided into three groups (n=10) of CPP-ACPF, fluoride and CPPACP. The teeth were micro-abraded with Opalustre. Microhardness test was performed to assess the post-abrasion hardness. Three remineralization modalities were performed on samples of each group. The enamel surface microhardness measurements were performed. To compare the difference between groups, the rehardening and softening values were defined. One-way ANOVA and Tukey's post hoc test at a significance level of 5% were used for statistical analysis.

RESULTS

The mean microhardness value (MMV) had a significant decrease after microabrasion from baseline. The MMV had a significant increase after remineralization in all groups. The MMV of CPP-ACPF group was significantly more than that of fluoride group (P=0.027). The rehardening value of fluoride group was significantly more than that of other groups (P<0.001).

CONCLUSION

All the remineralizing agents were effective for rehardening the enamel after microabrasion. The CPP-ACP and CPP-ACPF pastes are effective, but to a lesser extent than neutral sodium fluoride gel in remineralizing enamel surface. Incorporation of fluoride to CPP-ACP formulation does not provide any additional remineralizing potential.

Comparison of nano-hydroxyapatite and sodium fluoride mouthrinse for remineralization of incipient carious lesions

OBJECTIVE

Dental caries is an infectious disease that can be prevented in several ways. The aim of this study was to compare the efficacy of sodium fluoride mouthrinse and nano- hydroxyapatite (nano-HA) for the remineralization of incipient caries.

MATERIALS AND METHODS

After obtaining different concentrations of nano-HA (0-2-5-10%), 60 sound premolars fixed in acrylic blocks were coated with nail polish except for one surface. Ten teeth (control group) were stored in distilled water and the remaining 50 samples were demineralized by immersion in 13 ml of 0.1 M lactic acid and 0.2% poly acrylic acid for 48 hours. Their microhardness was then measured and compared to that of the control group. Next, the 50 test teeth were randomly divided into 5 groups of group1 (negative), group 2 (2% nano-HA), group 3 (5% nano-HA), group 4(10% nano-HA) and group 5 (0.2 NAF mouthrinse). The microhardness of the teeth was measured after 12 hours of immersion in the above-mentioned solutions. Data were analyzed using repeated measures analysis of variance (ANOVA).

RESULTS

Microhardness of all samples decreased significantly after immersion in the demineralization solution and increased following immersion in nano-HA and NAF mouthrinses; however, this increase was not statistically significant (P=0.711).

CONCLUSION

Nano-HA and NAF mouthrinses can greatly enhance remineralization and increase tooth microhardness.

The Effect of Calcium Pre-Rinse on Salivary Fluoride After 900 ppm Fluoride Mouthwash: A Randomized Clinical Trial

OBJECTIVE

Calcium fluoride deposit during fluoride application. Uptake and retention of fluoride by saliva depends generally on the concentration of calcium. In this study, the effect of calcium pre-rinse on salivary fluoride concentration after a 900 ppm fluoride mouthwash was investigated.

MATERIALS AND METHODS

This cross-over double-blind randomized clinical trial was conducted in a girls' dormitory in Zahedan University of Medical Sciences, southeast Iran. In this study, 42 female dental students were chosen using simple randomization. During the first phase, 21 subjects (group A) used fluoride rinse (F regimen) and the remaining (group B) used calcium pre-rinse followed immediately by fluoride rinse (Ca + F regimen). In the second phase, participants rinsed using the mouthwashes not previously used. Prior to each phase prophylaxis was performed and no fluoridated product was used during a two-week interval between the phases. Salivary samples were taken immediately before (baseline), 1 and 12 hours after rinsing. The salivary fluoride concentration was determined using fluoride sensitive electrode. Repeated measures ANOVA was used for statistical analysis and the significance level was set at P<0.05.

RESULTS

There was significant difference between fluoride concentrations at different time points (P< 0.001). Significant differences were observed when the different time points of two regimens were examined. In contrast to this, the baseline before using F regimen and the baseline before using Ca + F regimen did not show any significance (P= 0.070).

CONCLUSION

Pre-rinsing with calcium before fluoride is recommended because of significant increases in salivary fluoride concentration.

Remineralization Effect of Topical NovaMin Versus Sodium Fluoride (1.1%) on Caries-Like Lesions in Permanent Teeth

OBJECTIVE

NovaMin, a synthetic mineral composed of calcium, sodium, phosphorous and silica releases deposits of crystalline hydroxyl-carbonate apatite (HCA) structurally similar to tooth mineral composition. The aim of this investigation was to compare the potential remineralization effect of topical NovaMin and Sodium Fluoride gel on caries like lesions in permanent teeth.

MATERIALS AND METHODS

A total of 60 sound human freshly extracted teeth were subjected to a pH-cycling protocol. Specimens were randomly assigned to one of the two treatment groups with NovaMin contained dentifrice applied to group 1, while group 2 received a dentifrice containing 1.1% neutral Sodium Fluoride. Pastes were applied five times after the samples received a demineralization from an earlier cariogenic challenge. Specimens were then evaluated by a Surface Micro Hardness test (SMH, 25G, 5s). Post-treatment SMH measurements were conducted and Mann Whitney test was employed for statistical analysis.

RESULTS

Mean post lesion SMH values were 221.99±26.27 and 224.50±28.64 for the first and second groups, respectively. Post treatment SMH values were 232.52±24.34 for NovaMin and 232.03 ±24.46 for the fluoride group. Two way ANOVA test showed a highly significant difference between the two different treatment protocols (p<0.001).

CONCLUSION

NovaMin dentifrice appears to have a greater effect on remineralization of carious-like lesions when compared to that of fluoride containing dentifrice in permanent teeth.