pH Cycling Research Articles

Soil microbiological assessment on diversified annual cropping systems in China

Recent studies have demonstrated that monocropping of flue-cured tobacco can lead to various issues, including nutrient deficiencies, accumulation of allelopathic substances, and disturbance in soil microbial flora. While diversification in cropping systems has proven effective in alleviating monocropping barriers, however, further exploration is needed to understand the potential microbial mechanisms involved in this process. In our study, we set five cropping systems (RR: rice monocropping; TR: tobacco-rice rotation over 20 years; TRA: tobacco-rice-astragalus rotation; TRW: tobacco-rice-wheat rotation; TRO: tobacco-rice-oilseed rape rotation) to explore the impact on crop yield and quality, soil chemical properties, and microbial diversity. The results showed that the yield and gross margin were significantly decreased. Following diversification in cropping systems, particularly after implementing the TRA treatment, the yield and gross margin increased by 27.35% and 38.67%, respectively, compared to the TR treatment. Additionally, the presence of tobacco in the soil resulted in acidification, reduced soil fertility, and suppression of soil microorganism diversity and metabolite abundance. With diversification in cropping systems, there was an increase in soil pH, carbon and nitrogen cycle enzyme activities, and the relative abundance of beneficial microorganisms (acidobacteria, nitrospirillum, and ascomycota) and soil metabolites. Diversification in cropping systems has the potential to increase crop biomass, soil fertility, and soil microbial environment. Our results suggest a scientific foundation for implementing effective nutrient management practices and rational crop rotation systems.

Physio-Mechanic and Microscopic Analyses of Bioactive Glass-Based Resin Infiltrants.

This study aimed to investigate the efficacy and durability of bioactive glass-based dental resin infiltrants. Resin infiltrants were formulated by combining photoinitiated dimethacrylate monomers with three variations of bioactive glass: 45S5 Bioglass (RIS), boron-substituted (RIB), fluoride-substituted (RIF), and pure resins (PR), whereby TOOTH group (TH) and ICON (CN) served as commercial control groups. Teeth samples were prepared, and experimental and control infiltrants were applied on demineralized human-extracted teeth. All the samples were subjected to immersion in artificial saliva and pH cycling for 30 days. The samples from another group underwent tooth brushing simulation for 9600 cycles. Following artificial saliva immersion, the samples' hardness values showed that RIB had the highest values (318.44 ± 3.83) while PR (212.52 ± 9.02) had the lowest values. After immersing into the pH cycling solution, the RIF showed the highest hardness (286.86 ± 5.11), while the lowest values for the CN (143.76 ± 3.50). After the tooth brushing simulation, the teeth samples with RIB showed maximum microhardness values (312.06 ± 16.30) and the weakest for the TH (189.60 ± 6.43). The commercial and experimental enamel resin infiltrants showed almost similar results overall, with RIB demonstrating better microhardness and comparable surface roughness. In contrast, RIF proved more resistant to pH cycling, exhibited higher microhardness, and performed better in surface roughness analysis. These findings suggest that resin infiltrant materials, especially RIF, have promising potential for effectively and esthetically managing white spot lesions.

Enhancement of the rice protein solubility using industry-scale microfluidization and pH cycling: A mechanistic study

Enhancement of the rice protein solubility using industry-scale microfluidization and pH cycling: A mechanistic study

MMP Inhibition, Marginal Integrity and Cytotoxicity of Zinc-Releasing GIC

ObjectivesThe degradation of the restorative-dentin interface due to endogenous dentin enzymes, such as matrix metalloproteinases (MMPs), is a significant issue that accelerates the deterioration of the dentin matrix and leads to the failure of restorative treatments. Caredyne Restore (CR), a novel glass ionomer cement (GIC) with zinc ions in its formulation, represents the latest effort to mitigate this issue. This investigation aimed to evaluate the MMPs inhibitory effect, marginal integrity, and cytotoxicity of CR compared to a conventional GIC, Fuji IX (FIX). MethodsThe inhibitory effect of CR on MMPs activity was evaluated using in-situ zymography to visualize the endogenous gelatinolytic activity in the GIC-dentin interface. Additionally, CR's sealing properties were investigated using dye-assisted confocal laser microscopy (CLSM) to assess marginal leakage across the GIC-dentin interface. Both in-situ zymography and CLSM observations were conducted 1 day and seven days after pH cycling. Finally, the cytotoxicity of the GIC eluates was examined on rat dental pulp cells (RPC-C2A). Assay measurements were performed after 24 and 48 h of incubation with test solutions prepared using various GIC eluate concentrations. ResultsThe MMPs activity of the CR specimens was significantly lower than that of FIX specimens after seven days of pH cycling. Signs of marginal leakage were also lower in the CR specimens. Comparison of CR and FIX eluates at the same concentration showed no significant difference in terms of biocompatibility. ConclusionsCaredyne restore is capable of inhibiting endogenous enzyme activity and improving sealing properties, while maintaining sufficient biocompatibility. Clinical SignificanceZinc ions released from Caredyne Restore offer a safe way to improve the quality of dental restorations and promote minimally invasive treatment, especially in lesions where the dentin matrix is susceptible to enzymatic degradation and recurrent caries.

Formulation of Cushion Preparations from Duck Egg Shells and SPF Value Testing Using the UV-Vis Spectrophotometry Method

The effectiveness of a sunscreen can be indicated by the value of Sun Protection Factor (SPF), which is defined as the amount of UV energy needed. Cream is a semi-solid dosage from containing one or more medicinal ingredients dissolved or dispersed in a suitable base material. One of the compounds contained in eggshells is CaCO3. Calcium carbonate is necessary for cell regeneration and as a barrier to ultaviolet (UV) rays. This study aims to determine the potential SPF in duck eggshell, the SPF value contained in the cushion and the physical properties of the cushion preparation. Here, three variations of duck egg shell flour concentrations (4%, 8% and 16%) were made, tested in vitro using UV-Vis spectrophotometry from a wavelength of 290-320 nm every 5 nm and the absorbance was measured and the properties were tested. and physical stability (organoleptic, pH, spreadability, stickiness, viscosity, centrifugation, and Freeze-Thaw Cycling for 6 days (3 cycles) at temperatures of 40°C and 4°C). Our research results show that the duck egg shell formulation cannot be used as an SPF product. Formula 1 has an SPF value of 2.6, formula 2 has an SPF value of 3.3 and formula 3 has an SPF value of 3. The test results for the properties and stability of formula 2 with a concentration of 8% duck egg shell flour show the most stable results compared to the other 2 formulas

Effects of glutathione and potassium iodide on silver diamine fluoride application on remineralisation and colour change in dentine caries of primary teeth: an in vitro study.

The aim of this study is to compare the effect of GSH (reduced glutathione) and KI (potassium iodide) on SDF (silver diamine fluoride) discolouration and dentine remineralisation. Sixteen primary molars were utilised, yielding 4 dentine specimens each. Three specimens per tooth were allocated: one as a control and the others to experimental groups. Initial microhardness measurements were taken from one remaining dentine specimen per tooth. Subsequently, all groups underwent exposure to a demineralisation solution. Colorimetry assessed specimen colour, and post-second microhardness measurements on demineralised specimens, treatments were administered as follows: group 1 (control, n = 16): 38% SDF, group 2 (n = 16): 38% SDF followed by KI, group 3 (n = 16): 38% SDF with 5% GSH added by weight. Following pH cycling across all groups, colorimetry reassessed 48 dentine specimens. Final microhardness measurements ensued, followed by statistical analysis. Normality was checked via Shapiro-Wilk, and homogeneity via Levene's test. Independent samples t test compared normally distributed groups; Mann-Whitney U compared non-normally distributed groups. ANOVA compared means of normally distributed groups, and Kruskal-Wallis for non-normally distributed ones. Repeated measures ANOVA compared dependent groups with normal distribution, and Friedman test for non-normal. Post hoc Bonferroni analyses identified significant differences. IBM SPSS 25 was used to conduct analyses. The mean ΔE* values for SDF and SDF + GSH groups were significantly higher than those of the SDF + KI group (p < 0.05). Significant differences in L* values during final colour measurement were noted between the SDF + KI group and both SDF and SDF + GSH groups (p < 0.05). Although mean remineralisation microhardness measurements were higher than mean demineralisation microhardness measurements in all groups, statistical significance was observed only in the SDF and SDF + KI groups (p < 0.05). The study found that the addition of 5% GSH by weight to SDF does not significantly affect discolouration. Moreover, the addition of 5% GSH to the SDF solution may have a minor impact on the remineralisation potential of SDF. The application of KI after SDF reduces discolouration and does not affect the expected remineralisation process.

In Vitro Models Used in Cariology Mineralisation Research-A Review of the Literature.

Dental caries remains a significant global health problem. One of the fundamental mechanisms underlying the development and progression of dental caries is the dynamic process of demineralisation/remineralisation. In vitro models have played a critical role in advancing our understanding of this process and identifying potential interventions to prevent or arrest dental caries. This literature review aims to provide a structured oversight of in vitro mineralisation models which have been used to study the tooth demineralisation/remineralisation process. Publications from 2019 to 2023 were screened to identify articles reporting the use of in vitro models to study the demineralisation/remineralisation of tooth caries. The included studies were methodologically assessed for their information on (i) substrate, (ii) lesion formation, and (iii) mineralisation models. The most reported substrates used in the studies were human teeth along with bovine incisors. Acetic/lactic buffers were the most common solutions to induce caries lesions. pH cycling was the most frequently used mineralisation model for simulating the daily change within the oral environment. This review discussed the advantages and limitations of various approaches. Standardisation of in vitro mineralisation models is crucial for enabling effective comparison between studies and advancing caries research.

Efficacy of silver diamine fluoride (SDF) in arresting dentin caries against inter-kingdom biofilms of Streptococcus mutans and Candida albicans.

To compare, in vitro, the efficacy of three proprietary silver diamine fluoride (SDF) products in mitigating progression of dentinal caries induced by an inter-kingdom, dual-species, bacterial-yeast biofilm. Human dentin blocks were demineralized to create artificial caries lesions and randomized into three SDF test groups: Saforide, Topamine, T-SDF, and an aqueous control (n = 26 per group). After application of foregoing SDF variants, the blocks were incubated with Streptococcus mutans and Candida albicans for 24 h for biofilm development, and subsequently subjected to a microbe-induced, pH-cycling process for 7 days, to mimic the oral eco-system. The biofilm cell viability and surface topography were assessed by colony-forming units (CFUs) and scanning electron microscopy respectively. The lesion depth and mineral density were evaluated by micro-computer tomography. SDF precipitate and matrix-to-mineral ratio were evaluated by X-ray diffraction and Fourier transform infrared spectroscopy, respectively. Standard, accepted methodology was used for all these evaluations and procedures. After pH cycling, the SDF groups demonstrated comparable inhibition of the biofilm relative to the control. the log CFU of S. mutans for Saforide, Topamine, T-SDF, and control were 6.69±0.73, 6.48±0.56, 6.63±0.66, and 8.01±0.45, respectively. For C. albicans, the log CFU were 4.86±0.44, 4.72±0.53, 4.92±0.29, and 5.60±0.27, respectively. The log CFU of S. mutans and C. albicans in the SDF groups were significantly lower than the control group (p<0.001). Further, the lesion depth decreased by approximately 14.79±7.00% in the SDF groups, while it increased by 11.07±8.61% in the control (p<0.001), and the mineral density increased by 16.36±4.58% in the SDF group, as opposed to a 5.59±2.64% reduction in the control (p<0.001) implying their caries mitigating effect. These findings were corroborated by SEM images of the lesions. SDF significantly mitigated dentin caries due to an assault by a polymicrobial plaque biofilm whilst arresting mineral loss and lesion growth. There was no difference in the caries-arresting efficacy of the compared SDF variants.

Stability and dissolution of single-crystalline iron oxide thin films in electrochemical environments

The stability of single-crystalline monolayer FeO(111) and 10 nm thin Fe3O4(111) films on Pt(111) upon exposure to environments of increasing chemical complexity has been studied with X-ray photoelectron spectroscopy, temperature-programmed desorption, in-situ scanning tunneling microscopy, and cyclic voltammetry. The well-defined oxide films, which were prepared under ultrahigh-vacuum conditions, were exposed to aqueous solutions of different pH and electrochemical cycling in pure and catechol-containing electrolyte. The films are stable in neutral (pH 7) and alkaline (pH 13) solutions both at open circuit conditions and during electrochemical cycling within the limits of hydrogen and oxygen evolution potentials. Also in strongly acidic (pH 1) perchlorate solution the films remain intact under open circuit conditions, but they quickly dissolve on application of electrochemical potential. Especially for the ultrathin FeO(111) films, catechol enhances the dissolution at neutral pH during electrochemical cycling. A comparison of Pt(111), FeO(111) and Fe3O4(111) substrates in the electrochemical catechol oxidation reaction reveals enhanced and sustained activity of FeO in alkaline environment, while strong deactivation occurs on Pt(111) and Fe3O4(111). This is explained by the weaker interaction between catechol and FeO(111) compared to the other substrates, which hampers the formation of a barrier layer on the electrode surface.

Evaluation of the Remineralization Potential of an Herbal Non-fluoridated Dentifrice on Carious Lesions: An In Vitro Study

Background: This in vitro study compared the remineralization potential of Dabur red (DR), a non-fluoridated herbal toothpaste, with Colgate Strong Teeth (CST), a fluoride-based toothpaste, on permanent teeth with artificially created white spot lesions. Vickers microhardness (VMH), quantitative light-induced fluorescence system (QLF), and scanning electron microscopy (SEM) were used for data analysis. Methods: Enamel samples were prepared from the buccal surface of forty-five extracted maxillary premolars and subjected to demineralization to achieve adequate fluorescence loss (ΔF). The samples were divided into DR, CST, and control groups (n=15) and underwent 21 days of pH cycling. VMH was measured at baseline and after 21 days. QLF imaging was performed on days 7, 14, and 21. One randomly selected sample from each group underwent SEM examination to compare morphological variations. The statistical analysis was conducted using SPSS 22.0. Intra-group comparisons were made with repeated measures of analysis of variance (ANOVA), and one-way ANOVA with Tukey’s post-hoc test was utilized for inter-group comparisons (P&lt;0.05). Results: Mean VHN increased significantly in all three groups from baseline (DR=40.47, CST=41.91, control=36.42) to the 21st day (DR=119.47, CST=120.36, control=74.36) (P=0.00). Significant differences were found between the control and test groups, but not between DR and CST. No statistically significant difference was observed in ΔF at baseline and 7 days, but there were significant differences among the groups at 14 and 21 days. SEM images revealed dense mineralization for both DR and CST. Conclusion: After 21 days of in vitro remineralization, both DR and Colgate toothpaste demonstrated similar remineralizing potential as evaluated by surface MH and QLF.

Comparison of remineralizing efficacy of two novel preparation of arginine and theobromine on white spot lesion - an in vitro SEM analysis

ABSTRACT Purpose Evaluation of the efficacy of two novel formulations of arginine and theobromine in remineralizing artificial enamel defects using in vitro testing techniques- Microhardness and SEM Materials and methods Enamel slabs measuring 3 mm by 3 mm by 1.5 mm were created using 11 healthy premolars that were excised for orthodontic treatment. Group 1 (control, treated with merely a remineralization solution), Group 2 (0.05% arginine in 10 ml distilled water), and Group 3 (2% theobromine in 10 ml distilled water) were the three groups to which the slabs were randomly allocated (n = 7 per group). The pH cycle was run for 14 days, starting with a 72-h demineralization period and ending with 11 days of remineralization in the corresponding solutions. Prior to and during remineralization, microhardness was measured, and surface features were assessed using scanning electron microscopy (SEM). Statistical analysis, including Paired T Test, one-way ANOVA, and post hoc Tukey tests, determined that the mean values were significant at the 0.05 level. Results The control group showed a mean microhardness increase from 192.09 ± 19.30 to 208.58 ± 5.76. The arginine group increased significantly from 217.20 ± 4.24 to 304.00 ± 15.96, and the theobromine group from 214.09 ± 7.67 to 283.14 ± 10.91. Statistical analysis indicated that both arginine and theobromine groups had significantly greater microhardness improvements compared to the control (p < 0.05). SEM revealed that although arginine and theobromine enhanced enamel microhardness, surface morphology remained irregular and non-uniform. Conclusion Arginine and theobromine improve enamel microhardness and promote remineralization, but they do not create a uniform surface texture. Further research is needed to optimize their use and explore long-term effects on enamel surface uniformity.

Comparison of various chitosan-based in situ forming gels with sodium fluoride varnish for enamel biomineralization: an in-vitro pH cycling model

This study aimed to evaluate chitosan (CS)-based formulations loaded with 5% sodium fluoride (NaF) and/or 10% nanohydroxyapatite (nHA) to remineralize the demineralized primary tooth enamel surface. Ninety enamel blocks were demineralized and were divided into six groups (n = 15): (1) CS-based hydrogel, (2) CS-based hydrogel loaded with NaF, (3) CS-based hydrogel loaded with nHA, (4) CS-based hydrogel loaded with NaF and nHA, (5) 5% NaF varnish, and (6) negative control with no intervention. After intervention, the specimens were pH cycled by 2 h immersion in demineralizing solution and 22 h immersion in remineralizing solution for 8 days. The remineralization effects were evaluated by Vickers microhardness measurements and field emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (FESEM-EDS). The best mean ± SD percentage microhardness recovery in remineralized enamel (%REMH) was found in group 4 (56.90 ± 5.49). The %REMH of groups 2 (30.74 ± 3.51) and 5 (29.23 ± 5.65) were statistically the same (p = 0.943). FESEM images confirmed partial coverage of the porous demineralized enamel with a newly formed mineralized layer. Based on EDS findings, the Ca/P ratio values of the treated enamel surfaces with CS-based hydrogels ranged between 1.71 and 1.87, and the highest F content was noticed in group 2 (1.02 ± 0.03). Although, all tested CS-based hydrogels demonstrated the potential to repair demineralized enamel, nHA- and NaF-containing CS-based hydrogel showed the highest remineralization effect. We infer that this new hybrid hydrogel is a potentially useful dental material for tooth biomineralization.

Evaluation of the efficacy of various remineralization agents and grape seed extract on microhardness and lesion depth of primary tooth enamel: An in vitro study.

This study evaluated the efficacy of grape seed extract (GSE) on the remineralization of primary tooth enamel alone or in combination with remineralizing agents. The initial microhardness value of 90 primary tooth enamel samples was calculated; then, the samples were demineralized. The post-demineralization hardness of the samples was measured and the samples were randomly divided into 6 groups as follows: G1: negative control, G2: GSE, G3: NaF, G4:Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), G5: GSE+NaF, and G6: GSE+CPP-ACP (n=15). Oral environment pH cycle was applied and hardness measurements were repeated after treatments. The samples were stained with 1% rhodamine B dye and sectioned, and the lesion depth was measured. Statistical significance was set at P<0.05. The hardness decrease of the GSE and GSE+NaF groups was less than the other groups (P<0.05). The decrease was also less in the other groups than in the control group (P>0.05). GSE showed a positive effect when combined with NaF in maintaining microhardness but did not show the same effect when combined with CPP-ACP (P<0.05). Concerning penetration depth, all the groups had statistically lower values than the control group (P<0.05). The lowest penetration rates were observed in the GSE+NaF and GSE+CPP-ACP groups (P<0.05). The lowest hardness decrease was observed in the GSE and GSE+NaF groups, and the lowest penetration rates were observed in the GSE+NaF and GSE+CPP-ACP groups. It has been determined that a 15% GSE solution might be used as an alternative to fluoride in primary tooth remineralization and can increase the effectiveness of fluoride when used together.

Effect of cationized guar gum on stability and bioaccessibility of curcumin-loaded Pickering emulsion stabilized by starch nanoparticles

To enhance stability and bioaccessibility of curcumin in Pickering emulsions stabilized by starch nanoparticles (SNP), cationized guar gum (CGG) was incorporated into the emulsion. Zeta potential results revealed that SNP and CGG formed electrostatic interactions, resulting in stable interfacial layer with higher hydrophobicity. Adding 0.4 % CGG maintained a homogeneous phase without significant droplet size change for up to one month. The emulsion with 0.4 % CGG demonstrated stable storage under varying pH (4–10), ionic strength (0–10 mM NaCl), and freeze-thaw cycles (up to 3). When optimized Pickering emulsion system was applied to curcumin encapsulation, curcumin-loaded emulsions were stably maintained for up to one month. The curcumin retained approximately 100 % stability under thermal (90 °C) and UV (12h) treatments. In the optimized emulsion, starch components resisted digestion in oral and gastroenteric phases but were primarily digested in small intestine, resulting in an increasing bioaccessibility from 88.23 to 96.92 %.

A comparison of conventional sodium fluoride varnish and nano-sodium fluoride varnish regarding enamel microhardness of deciduous teeth: an in-vitro study.

Dental caries is the most common chronic disease worldwide, and various forms of fluoride are considered useful preventive tools. The production of nanoscale materials can significantly improve their mechanical and chemical properties. The present study compared the microhardness of primary tooth enamel after applying sodium fluoride varnish (conventional) and nano-sodium fluoride varnish. Sixty-eight sound canine teeth were selected in this experimental study. The teeth were mounted so that the buccal surface was exposed. A 3 × 3mm square was obtained on the buccal surface of the crown of each tooth. Enamel surfaces were polished using sandpaper in the presence of water as a coolant. The samples were randomly divided into four groups (n = 17): G1, conventional 5% NaF; G2, 1% nano-NaF; G3, 5% nano-NaF; G4, control. The initial microhardness was measured. Before surface treatment with different fluoride compounds, the samples were placed in a demineralizing solution for two days, and the microhardness of all the samples was re-measured. Then G1, G2, and G3 were treated with the fluoride type specified for each group, and G4 was treated as a control (without treatment). Finally, pH cycling was applied, and the microhardness was measured again. Data were analyzed with SPSS 20, using Repeated measure ANOVA and post-hoc Tukey tests. P < 0.05 was considered significant. Repeated measure ANOVA showed that microharness of G1, G2, G3, and G4 was statistically significant different. Tukey tests showed that the microhardness of G1, G2, and G3 were not significantly different. However, these three groups exhibited significantly more microhardness than the control group (P = 0.024, P = 0.027, and P = 0.010). There was no significant differences in enamel microhardness of deciduous teeth between conventional 5% NaF,1% nano-NaF and 5% nano-NaF.

Surface and Mineral Changes of Primary Enamel after Laser Diode Irradiation and Application of Remineralization Agents: A Comparative In Vitro Study.

The purpose of this study is to evaluate the remineralization potential of primary teeth enamel after being exposed to different laser diode therapies. Ninety-six vestibular primary teeth enamel samples were divided into eight groups (n = 12) with varying treatments: control (G1), CPP-ACP-fluoride varnish (G2), diode lasers at 980 nm (G3), 808 nm (G4), 450 nm (G5), 980 nm + CPP-ACP-fluoride varnish (G6), 808 nm + CPP-ACP-fluoride varnish (G7), and 450 nm + CPP-ACP-fluoride varnish (G8). Each sample was assessed using a DIAGNOdent® (KaVo Dental, Biberach, Germany), at baseline, post-treatment, and post-pH cycle remineralization. SEM imaging was performed before and after treatment and following the pH cycle. The results indicated that the 980 nm and 808 nm diode lasers, both alone and in combination with CPP-ACP-fluoride varnish, either maintained or increased the calcium (Ca) weight percentage (Wt%) in the enamel. The 980 nm diode laser combined with CPP-ACP-fluoride varnish (G6) showed a significant increase in Ca Wt%, suggesting a strong remineralization effect. Similarly, the 808 nm diode laser alone (G4) also promoted a substantial increase in Ca Wt%. In contrast, the 450 nm diode laser, whether applied alone or in combination with CPP-ACP-fluoride varnish, resulted in a lower Ca Wt% and an increase in phosphorus (P) Wt%. Most groups, except for the CPP-ACP-fluoride varnish alone (G2), demonstrated an increase in P Wt%, indicating a complex interaction between laser therapy and enamel remineralization. The combined use of laser therapy with CPP-ACP-fluoride varnish significantly enhanced the remineralization of temporary teeth enamel. The 980 nm diode laser + CPP-ACP-fluoride varnish showed the most pronounced improvement in remineralization, while the 808 nm diode laser alone also effectively increased calcium solubility. These findings suggest that higher-wavelength diode lasers, particularly when combined with remineralizing agents, can effectively enhance the mineral content of primary teeth and promote enamel remineralization.

Effects of graphene oxide and graphene quantum dots on enhancing CPP-ACP anti-caries ability of enamel lesion in a biofilm-challenged environment

ObjectiveTo investigate the anticaries effects of graphene oxide (GO) and graphene quantum dots (GQDs) combined with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on enamel in a biofilm-challenged environment. Material and methodsGO and GQDs were synthesised using citric acid. The antibiofilm and biofilm inhibition effects for Streptococcus mutans were evaluated by scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM), and colony-forming units (CFU). Remineralisation ability was determined by assessing mineral loss, calcium-to-phosphorus ratio, and surface morphology. To create a biofilm-challenged environment, enamel blocks were immersed in S. mutans to create the lesion and then subjected to artificial saliva/biofilm cycling for 7 days. Anticaries effects of GO, GQDs, GQDs@CPP-ACP, GO@CPP-ACP, and CPP-ACP were determined by broth pH and mineral changes after 7-day pH cycling. Biocompatibility was tested using a Cell Counting Kit-8 (CCK8) assay for human gingival fibroblasts (HGF-1). ResultsGQDs and GO presented significant antibiofilm and biofilm inhibition effects compared to the CPP-ACP and control groups (P < 0.05). The enamel covered by GQDs and GO showed better crystal structure formation and less mineral loss (P < 0.05) than that covered by CPP-ACP alone. After 7 days in the biofilm-challenged environment, the GO@CPP-ACP group showed less lesion depth than the CPP-ACP and control groups (P < 0.05). GO and GQDs showed good biocompatibility compared to the control group by CCK8 (P > 0.05) within 3 days. ConclusionGO and GQDs could improve the anti-caries effects of CPP-ACP, and CPP-ACP agents with GO or GQDs could be a potential option for enamel lesion management.Clinical Significance: GO and GQDs have demonstrated the potential to significantly enhance the anticaries effects of CPP-ACP. Incorporating these nanomaterials into CPP-ACP formulations could provide innovative and effective options for the management of enamel lesions, offering improved preventive and therapeutic strategies in dental care.

Remineralizing effect of NSF on artificial enamel caries

IntroductionNanotechnology offers new approaches and endless opportunities for remineralizing tooth decay without being toxic or causing allergies. This study aimed to determine the effect of nanosilver fluoride (NSF) on the remineralization potential of enamel caries-like lesions compared to 5% sodium fluoride varnish in permanent teeth.MethodsFifteen teeth (molars and premolars) were gathered, cleaned, and polished using a scaler. After sectioning the teeth mesiodistally and removing the roots, the thirty specimens were subjected to a demineralized solution to induce early enamel lesions and then assigned randomly into two equal groups. The test materials were applied, and then all the specimens were subjected to a pH cycling model for 30 days. DIAGNOdent and surface roughness were investigated, and an evaluation of the enamel Ca and P weight% for Ca/P ratio calculation was done using SEM-EDX to analyze the specimens at the end of the study. The data were analyzed using an independent t-test.ResultsThe mean values for the DIAGNOdent measurements for NSF and NaF at baseline and after demineralization were not significantly different (p > 0.05). After treatment, NaF varnish showed a significantly higher mean DIAGNOdent measurement (11.8 ± 5.80) than NSF (4.7 ± 1.6). The mean surface roughness of the NaF group (1.64 ± 0.39) was much higher than NSF’s mean surface roughness (1.07 ± 0.21). Specimens treated with NSF had statistically significant smoother surfaces (p < 0.001). The NSF group had a higher mean Ca/P ratio (2.9 ± 0.35) than NaF (2.2 ± 0.11). This difference was statistically significant (p = 0.012).ConclusionThe study reveals that nano silver fluoride is a more effective treatment than sodium fluoride varnish in enhancing teeth’s clinical characteristics, particularly in terms of mineral content and surface roughness, suggesting it could be an improved strategy to prevent dental caries and maintain enamel integrity.

The color stability of artificial white spot lesions treated with resin infiltration after exposure to staining beverages

BackgroundTo evaluate the effect of staining beverages on the color-changing of resin-infiltrated artificial white spot lesions (WSLs).MethodsThirty-five artificial WSLs were created by pH cycling on flat bovine teeth specimens. The WSLs were treated with resin infiltration and were divided into five groups based on staining beverages: artificial saliva, coffee, wine, green tea, and Coca-Cola. These specimens were subjected to a 28-day exposure to the respective beverages. Color stability was assessed using a spectrophotometer at different time points: baseline, after 7, 14, 21, and 28 days of exposure, and repolishing. The color difference (∆E) between each time point and the baseline was calculated. Statistical analysis was performed using two-way measures ANOVA with a significance level of p = 0.05.ResultsAll resin-infiltrated specimens exposed to staining beverages for 7 days exhibited more significant color changes than those exposed to artificial saliva. The color change patterns varied based on the type of beverage. The color alterations intensified with extended immersion in the wine and Coca-Cola groups, while there were no significant differences in the color of specimens after 28 days of immersion in the coffee and green tea groups. However, after cleaning with pumice powder, all specimens showed significantly reduced color changes compared to those observed after 28 days of immersion, except those immersed in coffee.ConclusionsExposure of resin-infiltrated bovine tooth specimens to staining beverages resulted in a significant color alteration as the immersion time increased. However, the staining effect could be minimized by cleaning with pumice powder, except for the coffee group.Clinical relevanceAfter resin infiltration treatment, patients should be advised to minimize the consumption of colored beverages to prevent staining that could impact esthetic appearance.

Effect of the use of remineralization agents before resin infiltration on the treatment of initial enamel lesions: an in-vitro study

AimThis study aimed to evaluate the effect of the use of remineralization agents before the application of resin infiltration on the treatment of initial enamel lesions.Materials and methodsEighty buccal enamel samples were prepared from human molars, and artificial initial lesions were formed after 96 h of incubation with a demineralizing solution. The samples were randomly divided into 8 groups (n = 10) including a remineralizing agent (Tooth Mousse, Medical Mineral Gel, Remin Pro), resin infiltration (ICON), and a combined treatment of both. Remineralizing agents were applied in pH cycle for 7 days. Baseline, demineralization, and after-treatment fluorescence (FluoreCam and DIAGNOdent Pen), surface microhardness (HMV-2T), surface roughness (M300C), OCT (Maestro-2) and ultrasonic system (Novascope 4500) data were obtained for all groups. The sample surfaces were examined under SEM/EDX (SU3500) at x1000. Data were statistically analyzed using the Two-Way Robust ANOVA and Bonferroni tests (p < 0.05).ResultsThere was no statistically significant difference between the groups for microhardness, roughness, OCT, DIAGNOdent Pen, ultrasound, and FluoreCam size/intensity values (p = 0.582; p = 0.963; p = 0.884; p = 0.923; p = 0.051; p = 0.268; p = 0.793 respectively). The effect of the treatment procedure showed a significant difference (p < 0.001), except for the roughness values (p = 0.984). The lowest Calcium (Ca) ratio (%atomic) was observed in the RI group in the EDX analysis.ConclusionRemineralizing agents and resin infiltration methods may be used in combination or alone in the treatment of initial enamel lesions. Combining remineralizing agents with resin infiltration does not alter the efficacy of the treatment.