Protective effect of various toothpastes and mouthwashes against erosive and abrasive challenge on eroded dentin: an in vitro study

The study aimed to compare various toothpastes and mouthwashes on permanent tooth dentin after erosive and abrasive challenges. 130 sound premolars dentin were randomly submitted to an initial erosive challenge and a cycle of erosive and abrasive challenges for five days. The five experimental groups (n = 26) were: (1) Control group (artificial saliva), (2) Elmex erosion protection toothpaste and mouthwash, (3) Vitis anticaries biorepair toothpaste and mouthwash, (4) Oral B Pro-expert toothpaste and Oral B Fluorinse mouthwash, and (5) MI Paste ONE toothpaste and Caphosol mouthwash. Microhardness, surface roughness values, and the topographical characteristics of the dentin surface were assessed. The highest percentage of recovered dentin microhardness (%RDMH) value was observed in groups 2 and 4, followed by groups 5 and 3, respectively. The %RDMH values in groups 2 and 4 did not demonstrate a significant difference (p = 0.855). The highest percentage of improvement in surface roughness was recorded in groups 2 and 4, with no significant differences (p = 0.989). The atomic force microscopy (AFM) findings were consistent with the surface roughness data. The best recovery of dentin microhardness and roughness were measured with the Elmex and Oral B toothpaste and mouthwash, followed by MI Paste ONE toothpaste and Caphosol mouthwash and Vitis anticaries biorepair toothpaste and mouthwash.

Clinical and ex-vivo effect of LASERs on prevention of early-enamel caries: systematic review & meta-analyses

To investigate the in vivo and in situ effect of different types of lasers in prevention of enamel demineralization in high caries risk cases (around orthodontic brackets, around restoration and in caries susceptible pits and fissures). PubMed was searched using the following keyword sequence; (Laser therapy OR laser irradiation OR laser application) AND (enamel caries prevention OR enamel demineralization OR enamel remineralization OR early enamel caries OR early-enamel caries OR enamel resistance OR enamel decalcification OR white spot lesions WSLs OR incipient lesion OR enamel decay OR enamel Dissolution OR enamel microhardness) AND (clinical trial OR Randomized clinical trial OR In situ study). The latest literature search was ended by "30 January 2023". PubMed was used as a primary data base for study selection. Scopus, EBSCO, and Google scholar are checked in our study after results of systematic search on PubMed. Only duplicates were found. Two meta-analyses were carried out. The first, clinical meta-analysis on incidence of white spot lesions (WSLs) following CO2 laser irradiation of enamel. The second meta-analysis on ex-vivo/in situ effect of CO2 laser on microhardness of enamel. In each meta-analysis three studies were included. Risk of bias was assessed. The search identified eight studies (four ex-vivo and four clinical trials). Regarding the clinical meta-analysis, the overall standardized mean difference was 0.21 [ 95% confidence interval (CI): 0.15-0.30, p < 0.00001]. This indicates that the incidence of new WSLs in patients who received low power CO2 laser treatment was highly significantly lower than placebo groups. The heterogeneity was considerable (I2 = 71%). In the second meta-analysis, the overall standardized mean difference was 49.55 [ 95% confidence interval (CI): 37.74, 61.37, p < 0.00001]. This indicates that microhardness of enamel receiving low power (0.4-5 W) CO2 laser irradiation is highly significantly lower than control untreated enamel. The heterogeneity was substantial (I2 = 48%). Within the limitations of this study, Low level laser therapy concept with CO2 laser seems to be effective in preventing enamel caries.Prospero registration number: CRD42023437379.

Enamel changes of bleached teeth following application of an experimental combination of chitosan-bioactive glass

BACKGROUND

Considering the extensive use of bleaching agents and the occurrence of side effects such as enamel demineralization, this study aimed to assess the enamel changes of bleached teeth following the experimental application of chitosan-bioactive glass (CH-BG).

METHODS

In this in vitro study, CH-BG (containing 66% BG) was synthesized and characterized by Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thirty sound human premolars were bleached with 40% hydrogen peroxide, and the weight% of calcium and phosphorus elements of the buccal enamel surface was quantified before and after bleaching by scanning electron microscopy/ energy-dispersive X-ray spectroscopy (SEM, EDX). Depending on the surface treatment of the enamel surface, the specimens were divided into three groups (n = 10): control (no treatment), MI Paste (MI), and CH-BG. Then the specimens were stored in artificial saliva for 14 days. The SEM/EDX analyses were performed again on the enamel surface. Data were analyzed by one-way ANOVA and Tukey's test and a p-value of < 0.05 was considered statistically significant.

RESULTS

In all groups, the weight% of calcium and phosphorus elements of enamel decreased after bleaching; this reduction was significant for phosphorus (p < 0.05) and insignificant for calcium (p > 0.05). After 14 days of remineralization, the weight% of both calcium and phosphorus elements was significantly higher compared to their bleached counterparts in both MI and CH-BG groups (p < 0.05). Following the remineralization process, the difference between MI and CH-BG groups was not significant (p > 0.05) but both had a significant difference with the control group in this regard (p < 0.05).

CONCLUSIONS

The synthesized CH-BG compound showed an efficacy comparable to that of MI Paste for enamel remineralization of bleached teeth.

Mechanical properties of simulated dentin caries treated with metal cations and L-ascorbic acid 2-phosphate

This pH cycling study aimed to investigate the effects of L-Ascorbic acid 2-phosphate (AA2P) salts of Mg, Zn, Mn, Sr, and Ba on the surface microhardness, compressive strength, diametral tensile strength (DTS), and solubility of root canal dentin. 186 cylindrical dentin specimens from 93 teeth were fortified with optimal concentrations of AA2P salts of Mg (0.18 mM), Zn (5.3 µM), Mn (2.2 × 10-8 M), Sr (1.8 µM), and Ba (1.9 µM). Saline was used as the control group. These dentin specimens underwent a 3-day cycling process simulating dentin caries formation through repeated sequences of demineralization and remineralization. Surface microhardness at 100 and 500 µm depths (n = 10/subgroup), scanning electron microscopy (n = 3/group), compressive strength (n = 10/group), DTS (n = 6/group), and solubility (n = 5/group) tests were performed to analyze the dentin specimens. Data were analyzed using Kolmogorov-Smirnov, one-way ANOVA, and Post Hoc Tukey tests (p < 0.05). The control group had significantly lower microhardness at both depths (p < 0.001), reduced DTS (p = 0.001), decreased compressive strength (p < 0.001), and higher weight loss (p < 0.001) than all other groups. The Sr group had the highest compressive strength and microhardness among all the groups. The microhardness was significantly higher for the 500 µm depth than the 100 µm depth (p < 0.001), but the difference in microhardness between depths across groups was not significant (p = 0.211). All fortifying solutions provided some protection against artificial caries lesions. Therefore, these elements might have penetrated and reinforced the demineralized dentin against acid dissolution.

Remineralization potential of apacider mangosteen adhesive pastes on artificial carious lesions

Background/purpose

Attention to caries administration has altered toward an early finding of lesions and targeted to noninvasive management with a remineralizing agent. This study compared the remineralization potential of apacider mangosteen adhesive pastes (AMAP), 500-ppm fluoride toothpaste (FT500), and 1000-ppm fluoride toothpaste (FT1000) on artificial caries.

Materials and methods

Artificial caries were generated to enamel of eighty extracted human premolars. The specimens were allocated to four groups and subjected to pH-cycling with the application of testing agents (2 min each, for 10 days): (1) AMAP, dairy, (2) FT500, twice a day, (3) FT1000, twice a day, and (4) no treatment (NT). The surface microhardness was determined before demineralization, after demineralization, and after application of pH-cycling. The hardness, percent of hardness recovery (%HR), and percent of remineralization potential (%RP) were analyzed with ANOVA and Bonferroni's test (α = 0.05). Polarized light microscopy (PLM) was assessed for lesion depth.

Results

Significant differences in remineralization were observed upon various agents compared to NT (P < 0.05). A significant difference in remineralization was found among AMAP, FT1000, and FT500 (P < 0.05). No significant difference in %HR and %RP was observed between AMAP and FT1000 (P > 0.05). PLM signified greater decrease in depth for AMAP, compared to FT1000 and FT500, but no depth reduction for NT.

Conclusion

AMAP possesses comparable remineralization ability to FT1000. However, decreasing in depth of carious lesions was evinced with using AMAP more than FT1000 and FT500. AMAP was recommended as a potential remineralization material for handling initial caries.

Biomineralization and remineralizing potential of toothpastes containing nanosized β-calcium glycerophosphate: an in vitro study

To evaluate the effect of 1100 ppm F toothpastes supplemented with micrometric or nanosized β-CaGP (β-CaGPm/β-CaGPn) on artificial enamel remineralization, using a pH cycling model. Enamel blocks with artificial caries were randomly allocated into ten groups (n = 10), according to the toothpastes: without fluoride/β-CaGPm/β-CaGPn (negative control); 1100 ppm F (1100F); 1100F plus 0.125%, 0.25%, 0.5%, and 1.0% of β-CaGPm or β-CaGPn. The blocks were treated 2×/day with slurries of toothpastes. After pH cycling, the percentage of surface hardness recovery (%SHR); integrated loss of subsurface hardness (ΔKHN); integrated mineral loss (ΔIMR); fluoride (F), calcium (Ca), and phosphorus (P) concentrations in the enamel; polydispersity index (PdI); and zeta potential (Zp) were determined. The data were analyzed by ANOVA (p < 0.001). For Zp/PdI, no significance was observed when comparing the means (p > 0.001). The treatment with 1100F-0.25%β-CaGPn led to %SHR ∼57 higher when compared to the 1100F group (p < 0.001). The lowest ΔKHN was observed for the 1100F-0.25%β-CaGPn group (p < 0.001). The ΔIMR was lower (∼201%) for the 1100F-0.25%β-CaGPn when compared to 1100F (p < 0.001). The association of β-CaGPm and β-CaGPn to 1100F did not influence its F concentration (p > 0.001). The highest increase in Ca and P was observed for 1100F-0.25%β-CaGPn (p < 0.001). The addition of 0.25%β-CaGPn to 1100F toothpaste was able to promote an additional remineralizing effect of artificial caries lesions.

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.

Dentin remineralization using a stimuli-responsive engineered small molecule GSK3 antagonists-functionalized adhesive

OBJECTIVES

Tideglusib has shown great performance in terms of dentin regenerative properties. This study aims to evaluate bonding ability, of demineralized dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TG) (TG-NPs).

METHODS

Dentin conditioned surfaces were infiltrated with NPs and TG-NPs. Bonded interfaces were created and stored for 24 h and then submitted to mechanical, chemical and thermal challenging. The resin-dentin interface was evaluated through a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy, and by field emission scanning electron microscopy.

RESULTS

Dentin surfaces treated with TG-NPs and load cycled produced higher bond strength than the rest of the groups. Immersion of dentin specimens treated with undoped-NPs in collagenase solution attained the lowest microtensile bond strength (MTBS) values. Both porosity and nanoleakage decreased when dentin was infiltrated with TG-NPs, that revealed strong signals of xylenol orange stain at both hybrid layer and dentinal tubules. The presence of NPs, in general, inducted the presence of mineralized interfaces after mechanical loading and thermocycling.

CONCLUSIONS

Nanoparticles doped with tideglusib promoted the highest dentin bonding efficacy among groups, as they facilitated the maximum bond strength values with creation of mineral deposits at the hybrid layer and dentinal walls. Tideglusib enabled scarce porosity, nanoleakage and advanced sealing among dentin groups.

SIGNIFICANCE

Doping hydrophilic polymeric NPs with tideglusib, infiltrated in etched dentin represents a reproducible technique to create reparative dentin at the resin-dentin interface, by inducing therapeutic bioactivity.

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.

Epigallocatechin gallate-immobilized antimicrobial resin with rechargeable fluorinated synergistic composite for enhanced caries control

OBJECTIVES

Given the global prevalence of dental caries, impacting 2.5 billion individuals, the development of sophisticated prevention filling materials is crucial. Streptococcus mutans, the principal caries-causing strain, produces acids that demineralize teeth and initiate dental caries. To address this issue, we aimed to develop a synergistic resin-based composite for enhancing caries control.

METHODS

The synergistic resin composite incorporates fluorinated kaolinite and silanized Al2O3 nanoparticle fillers into an epigallocatechin gallate (EGCG) immobilized urethane-modified epoxy acrylate (U-EA) resin matrix, referred to the as-prepared resin composite. The EGCG-modified TPGDA/U-EA network was synthesized by preparing methacrylate-functionalized isocyanate (HI), reacting it with EGCG to form HI-EGCG, and then incorporating HI-EGCG into the TPGDA/U-EA matrix. The lamellar space within the kaolinite layer was expanded through the intercalation of acrylamide into kaolinite, enhancing its capability to adsorb and release fluoride ions (F-). The layered structure of acrylamide/ kaolinite in the U-EA resin composite acts as a F- reservoir.

RESULTS

The physico-mechanical properties of the as-prepared resin composites are comparable to those of commercial products, exhibiting lower polymerization shrinkage, substantial F- release and recharge and favorable diametral tensile strength. The immobilized EGCG in the composite exhibits potent antimicrobial properties, effectively reducing the biofilm biomass. Furthermore, the synergistic effect of EGCG and fluorinated kaolinite efficiently counteracts acid-induced hydroxyapatite dissolution, thereby suppressing demineralization and promoting enamel remineralization.

SIGNIFICANCE

Our innovative EGCG and fluoride synergistic composite provides enhanced antimicrobial properties, durable anti-demineralization, and tooth remineralization effects, positioning it as a promising solution for effective caries control and long-term dental maintenance.

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.

Nanotechnology in toothpaste: Fundamentals, trends, and safety

Several studies have revealed that healthcare nanomaterials are widely used in numerous areas of dentistry, including prevention, diagnosis, treatment, and repair. Nanomaterials in dental cosmetics are utilized to enhance the efficacy of toothpaste and other mouthwashes. Nanoparticles are added to toothpastes for a variety of reasons, including dental decay prevention, remineralization, hypersensitivity reduction, brightening, and antibacterial qualities. In this review, the benefits and uses of many common nanomaterials found in toothpaste are outlined. Additionally, the capacity and clinical applications of nanoparticles as anti-bacterial, whitening, hypersensitivity, and remineralizing agents in the treatment of dental problems and periodontitis are discussed.

Reinforced dentin remineralization via a novel dual-affinity peptide

OBJECTIVES

In light of the constantly flowing saliva, anti-caries remineralization agents are inclined to be taken away. Owing to their limited residence time, the remineralization effect is not as desirable as expected. Hence, our study aimed to synthesize a novel peptide (DGP) with high affinity to both collagen fibrils and hydroxyapatite, and investigated its dentin remineralization efficacy in vitro and anti-caries capability in vivo.

METHODS

DGP was synthesized through Fmoc solid-phase reaction. The binding ability and interaction mechanism of DGP to demineralized dentin were investigated. Dentin specimens were demineralized, then treated with DGP and deionized water respectively. The specimens were incubated in artificial saliva and in-vitro remineralization effectiveness was analyzed after 14 days. The rat caries model was established to further scrutinize the in-vivo efficacy of caries prevention.

RESULTS

DGP possesses an enhanced adhesion force of 12.29 ± 1.12 nN to demineralized dentin. The favorable adsorption capacity is ascribed to the stable hydrogen bonds between S2P-101 and ASP-100 of DGP and GLY33 and PRO-16 of collagen fibers. Abundant mineral deposits and remarkable tubule occlusion were observed in the DGP group. DGP-treated dentin obtained notable microhardness recovery and higher mineral content after a 14-day remineralization regimen. DGP also demonstrated potent caries prevention in vivo, with substantially fewer carious lesions and significantly lower Keyes scoring.

SIGNIFICANCE

DGP proves to possess a high affinity to demineralized dentin regardless of saliva flowing, thus enhancing remineralization potency significantly in vitro and in vivo, potential for dental caries prevention and combatting initial dentin caries clinically.

Efficacy of different remineralizing agents on primary teeth exposed to therapeutic gamma radiation: An in vitro randomized control study

Background

Therapeutic radiation-induced caries is a major side effect. Dental and oral heath are adversely affected by the direct effects of radiotherapy. Preventive procedures are preferred to reinforce dental tissue resistance against radiation damage.

Objective

Research aim is to test the impact of different remineralizing protocols on the mineral content of deciduous enamel exposed to a therapeutic dose of gamma radiation.

Methods

Thirty deciduous enamel specimens were divided randomly into three experimental categories based on the type of remineralizing agent used. Group I (gamma irradiated teeth, then painted with fluoride varnish), Group II (gamma irradiated teeth, then treated with bioactive glass) and Group III (gamma irradiated teeth, and then treated with a diode laser 980 nm). Prepared specimens were assessed for mineral content by environmental Energy Dispersive X-ray Analysis. SEM photomicrographs were performed simultaneously. Results were investigated concerning pre- and post-irradiation values difference. The paired-samples t-test was performed to compare the atomic and weight percentages of the selected elements obtained from the samples in the control groups before and after therapeutic radiation. One-way analysis of variance and post hoc Tukey tests were used to compare between the categories regarding weight and atomic percentages.

Results

Calcium/Phosphorus (Ca/P) ratio and Fluoride content decreased significantly after radiotherapy. Fluoride content significantly increased after remineralizing agents' application with the greatest increase in Bioactive glass group followed by fluoride varnish (F.varnish) group and the least increase was in diode laser group. Significant increase in Ca/P ratio in bioactive glass group followed by insignificant increase in F.varnish group (I) with the least increase noticed in the Diode laser group.

Conclusion

Therapeutic radiation caused marked decrease in enamel mineral content. However, the reminralizing agents applied have an improving effect on the caused damage.

Bioactivity and remineralization potential of modified glass ionomer cement: A systematic review of the impact of calcium and phosphate ion release

This systematic review investigates the effectiveness of calcium and phosphate ions release on the bioactivity and remineralization potential of glass ionomer cement (GIC). Electronic databases, including PubMed-MEDLINE, Scopus, and Web of Science, were systematically searched according to PRISMA guidelines. This review was registered in the PROSPERO database. Five eligible studies on modifying GIC with calcium and phosphate ions were included. The risk of bias was assessed using the RoBDEMAT tool. The incorporation of these ions into GIC enhanced its bioactivity and remineralization properties. It promoted hydroxyapatite formation, which is crucial for remineralization, increased pH and inhibited cariogenic bacteria growth. This finding has implications for the development of more effective dental materials. This can contribute to improved oral health outcomes and the management of dental caries, addressing a prevalent and costly oral health issue. Nevertheless, comprehensive longitudinal investigations are needed to evaluate the clinical efficacy of this GIC's modification.

Elevated internal phosphorus loading from shallow areas of eutrophic boreal lakes: Insights from porewater geochemistry

Internal phosphorus (P) loading is widely recognized as a major cause of lake eutrophication. One conventional paradigm states that the magnitude of internal loading through P diffusion is constrained by the presence of iron (Fe) oxides in surface sediments under oxic conditions near the sediment-water interface (SWI). However, biogeochemical P dynamics in Fe-rich sedimentary systems are still not fully understood, especially in eutrophic lakes where intensively coupled organic matter (OM) remineralization and reductive dissolution of Fe-bound P (Fe-P) exist concurrently. Here, we assess the diagenetic processes that govern sedimentary P cycling in two eutrophic Fe-rich lakes in southern Finland, Lake Hiidenvesi and Lake Kytäjärvi, using a combination of porewater and solid-phase analyses. Coupled reductive dissolution of Fe-P and OM remineralization controlled P regeneration in both lakes, with Fe-P acting as the dominant source for porewater P. Vivianite formation likely immobilized sedimentary P in the deepest basin of Hiidenvesi. Elevated P diffusion rates were observed at shallow sites under oxic bottom water conditions in summer in both lakes, stimulated by enhanced remineralization of both freshly- (mostly phytoplankton-origin) and earlier-deposited OM under elevated temperatures. Areas overlain by oxic bottom water contributed more benthic P fluxes to the water column compared to anoxic/hypoxic areas in both lakes during all sampling seasons. Our study suggests that in shallow eutrophic settings with high OM deposition and elevated temperatures, remineralization in upper sediments regenerates P efficiently enough to support a significant amount of P release to the water column even under sedimentary molar Fe/P ratios >20. We also discuss the implication of our findings for lake restoration strategies.

In vitro remineralization of adjacent interproximal enamel carious lesions in primary molars using a bioactive bulk-fill composite

BACKGROUND

Surface remineralization is recommended for the management of active non-cavitated interproximal carious lesions in primary teeth. According to the American Academy of Pediatric Dentistry, a recently recognized category of materials called bioactive restorative materials can be used for remineralization. This study aimed to evaluate the release of fluoride (F), calcium (Ca) and phosphate (P) ions from Predicta® Bioactive Bulk-fill composite compared with EQUIA Forte® and Filtek™ Z350 and to determine the remineralization effect of these 3 restorative materials on adjacent initial interproximal enamel carious lesions.

METHODS

The release of F, Ca and P ions from 3 groups ((n = 10/group) (Group 1- Predicta®, Group 2- EQUIA Forte® and Group 3- Filtek™ Z350)) was determined at 1st, 4th, 7th and 14th days. After creating artificial carious lesions, human enamel samples were randomly assigned into 3 groups (n = 13/group) which were placed in contact with occluso-proximal restorative materials and exposed to a 14-day pH cycling period. Surface microhardness was determined using a Knoop microhardness assay at baseline, after artificial carious lesions formation and after pH cycling. The difference in the percentage of surface microhardness recovery (%SMHR) among groups was compared. Mineral deposition was analyzed with energy-dispersive x-ray spectroscopy (EDS) and the enamel surface morphology was evaluated with scanning electron microscopy (SEM). Kruskal-Wallis's test with Dunn's post hoc test and one-way ANOVA with Tukey's post hoc test were used for data analysis.

RESULTS

EQUIA Forte® released the highest cumulative amount of F and P ions, followed by Predicta® and Filtek™ Z350. Predicta® released higher amount of Ca ions than EQUIA Forte® and Filtek™ Z350. Predicta® demonstrated the highest %SMHR, followed by EQUIA Forte® and Filtek™ Z350. There was a significant difference in the %SMHR between Predicta® and Filtek™ Z350 (p < 0.05). However, EQUIA Forte® demonstrated the highest fluoride content, followed by Predicta® and Filtek™ Z350. The SEM images of EQUIA Forte® and Predicta® revealed the greater mineral deposition.

CONCLUSION

Predicta® demonstrated a marked increase in surface microhardness and fluoride content of adjacent initial interproximal enamel carious lesions in primary molars compared with Filtek™ Z350. Predicta® is an alternative restorative material to remineralize adjacent initial interproximal enamel carious lesions in primary molars, especially in high-risk caries patients.

Encapsulation of a novel peptide derived from histatin-1 in liposomes against initial enamel caries in vitro and in vivo

OBJECTIVES

Biomimetic mineralization mediated by proteins and peptides is a promising strategy for enamel repair, and its specific application model needs more research. In this work, we exploited a liposomal delivery system for a novel peptide (DK5) derived from histatin-1 (DK5-Lips) as a new biomimetic mineralization strategy against initial enamel caries.

MATERIALS AND METHODS

The DK5-Lips was prepared using calcium acetate gradient method and then the in vitro release, salivary stability, and cytotoxicity were studied. Initial enamel caries was created in bovine enamel blocks and subjected to pH-cycling model treated with DK5-Lips. Surface microhardness testing, polarized light microscopy (PLM), and transverse microradiography (TMR) were analyzed. Then the biocompatibility of DK5-Lips was evaluated in the caries model of Sprague-Dawley rats, and the anti-caries effect was assessed using Micro-CT analysis, Keyes scores, and PLM in vivo.

RESULTS

DK5-Lips provided a mean particle size of (97.63 ± 4.94)nm and encapsulation efficiency of (61.46 ± 1.44)%, exhibiting a sustained release profile, excellent stability in saliva, and no significant toxicity on human gingival fibroblasts (HGFs). The DK5-Lips group had higher surface microhardness recovery, shallower caries depth, and less mineral loss in bovine enamel. Animal experiments showed higher volume and density values of residual molar enamel, lower Keyes score, and shallower lesion depth of the DK5-Lips group with good biocompatibility.

CONCLUSION

As a safe and effective application model, DK5-Lips could significantly promote the remineralization of initial enamel caries both in vitro and in vivo.

CLINICAL RELEVANCE

The potential of liposome utilization as vehicle for oral delivery of functional peptides may provide a new way for enamel restoration.

Remineralization ability of different root canal sealers

Aims

This research was designed to contrast the biocompatibility and remineralization ability of different sealers (BioRoot, MTA-FillApex and GuttaFlow-Bioseal).

Method

Twenty rabbits were used in this study, they were randomly divided into 4 groups equally depending on the observation time"3,7,14, and 28 days" post-implantation. Each rabbit was generally anesthetized,"7cm"long incision was made on the skin of the right and left sides of the ventral aspect of the mandible of each rabbit, 4 bony cavities of approximately"5mm"in depth and"2mm"in diameter (2 cavities on the left side and 2 cavities on the right side of mandible of each rabbit) were made in the cortical surface of the buccal alveolar bone. The sealers mixed depend on manufactural instructions and immediately insert into the prepared cavities (in the right side the BioRoot and MTA-FillApex were placed while on the left side, GuttaFlow-Bioseal was placed in one cavity and the other cavity was left unfilled as control).The same volume of each sealer was placed in the corresponding cavity using disposable syringes. After each observation period, the animals were sacrificed and bone biopsy from the tested area was taken and examined histologically using Olympus light microscopy at"400X"magnification.

Results

The obtained data were analyzed through non-parametric statistical tests using SPSS software version"22".Kruskal-Wallis test and Mann - Whitney test were utilized at"0.05"levels of significance to evaluate the results. GuttaFlow-Bioseal displayed excellent biocompatibility in comparison to other groups indicated by low inflammatory tissue reaction at all evaluation intervals. While the BioRoot group represented better osteo-conductivity although statistically not significant than GuttaFlow-Bioseal group.

Conclusion

BioRoot and GuttaFlow-Bioseal showed higher osteo-conductivity and biocompatibility than MTA-FillApex. However, all sealer used in this study were well tolerated by bone tissue and might accelerate bone repair.

Effect of re-mineralizing surface treatment on the shear bond strength of orthodontic bracket: A systematic review and meta-analysis of in-vitro studies

INTRODUCTION

Re-mineralizing surface pretreatment is essential for both controlling and preventing white spot lesion (WSL) throughout the time of fixed orthodontic treatment. It is also important that the re-mineralizing have no negative impact on the bonding between the bracket, adhesive, and enamel. Therefore, this review is aimed to investigate the orthodontic brackets' shear bond strength after re-mineralizing surface treatment of enamel.

MATERIAL AND METHODOLOGY

The review was conducted following the PRISMA 2020 guidelines. In-vitro experimental studies measuring shear bond strength (SBS) of orthodontic brackets on both demineralized and intact enamel following re-mineralizing surface treatment were included. Database search was done in PubMed, Scopus, and Science Direct during July 2023. Methodological quality of the studies was assessed according to the guidelines for the reporting of pre-clinical in-vitro studies. Both qualitative and quantitative analyses of the included studies were done.

RESULTS

Matching the inclusion criteria, 46 and 37 studies were selected for qualitative and quantitative analysis respectively. On intact enamel re-mineralizing agents had no negative impact on the brackets' SBS. On the contrary, they seemed to enhance the bond strength remarkably on the demineralized enamel.

DISCUSSION

Re-mineralizing surface pretreatment is crucial prior to fixed orthodontic treatment as it did not reduce the bond strength. Although, it cannot be judged depending solely on the in-vitro results with high heterogeneity. Clinical evidence is required to support the statement.

Loss of POC and DOC on seagrass sediments by hydrodynamics

Coastal development and climate change are sparking growing concern about the vulnerability of the organic carbon (OC) stocks in marine sediments to remineralization, especially in high threaten coastal ecosystems like seagrass meadows. Uncertainties still exist regarding the role played by hydrodynamics, seagrass canopies and sediment properties in OC resuspension and remineralization. A set of laboratory experiments were conducted to assess, for the first time, the mechanisms by which the particulate and dissolved organic carbon (POC and DOC) may be released and remineralized under hydrodynamic conditions (i.e., unidirectional and oscillatory flows) in two eelgrass densities and sediments properties (i.e., grain size and OC content). After a gradually increase in hydrodynamic forces, our results demonstrated that the presence of eelgrass reduced sediment erosion and OC loss in high-density canopies, while low-density canopies promote OC resuspension (on average, 1.8-fold higher than high-density canopies). We also demonstrated that unidirectional and oscillatory flows released similar DOC from surface sediments (on average, 15.5 ± 1.4 and 18.4 ± 1.8 g m-2, respectively), whereas oscillatory flow released significantly more POC than unidirectional flows (from 10.8 ± 1.1 to 32.1 ± 5.6 g m-2 for unidirectional and oscillatory flows, respectively). POC and DOC released was strongly influenced by both seagrass meadow structure (i.e., lower eelgrass density and shoot area) and sediment properties (i.e., lower mud and higher sediment water content). We found that, although >74 % of OC in upper sediments was remineralized within 30 days, a relatively high amount of OC in high-density canopies is recalcitrant, highlighting its potential for the formation of blue carbon deposits. This study highlights the vulnerability of OC deposits in seagrass sediments to resuspension if the meadow is degraded and/or the climate change yield stronger storms, which could potentially weaken the seagrass meadows' service as blue carbon ecosystem in the future.

Evaluation of flexural strength, degree of conversion, and demineralization-prevention properties in adjacent tooth structures of an experimental fissure sealant containing nano-calcium-phosphate compounds

BACKGROUND

The present study aimed to evaluate the flexural strength, degree of conversion, and demineralization-prevention ability of an experimental fissure sealant containing nano-calcium-phosphate compounds.

METHODS

An experimental sealant was formulated using silica and nano hydroxyapatite filler particles. The control group consisted of the DENU Seal (n = 10, each group). The flexural bond strength was evaluated by UTM. DC was evaluated by FTIR. To evaluate the demineralization-prevention ability, Cl V cavities in 10 third molar teeth restored with two sealant products, followed by an acid challenge then the Vickers microhardness test was carried out.

RESULTS

The mean flexural strength in the commercial group was higher than the experimental group. However, the mean flexural modulus was not significantly different between the two groups. In the experimental group, DC was significantly higher than the commercial group. Adjacent to the interface, the decrease in microhardness in the experimental group was significantly less than the commercial group. However, on the tooth surface, there were no significant differences between the two groups. In the experimental group, the decrease in microhardness at the interface was less than at the tooth surface, however the situation was opposite in the commercial group.

CONCLUSIONS

Incorporating hydroxyapatite into the sealant structure might prevent demineralization, without adverse effects on flexural modulus and degree of conversion.

Surface topography and spectrophotometric assessment of white spot lesions restored with nano-hydroxyapatite-containing universal adhesive resin: an in-vitro study

BACKGROUND

White spot lesion (WSL) is a main shortcoming accompanied by orthodontic treatment. It impairs the esthetic, surface hardness, and surface texture of enamel. So, this study was conducted to analyze the surface characteristics and color change of white spot lesions treated with nano-hydroxyapatite (nHA)-enriched universal adhesive resin.

MATERIALS AND METHODS

Eighty sound human permanent molars crowns were sectioned into two halves, producing 160 specimens. 16 specimens were left untreated, and 144 specimens were artificially-demineralized to generate WSLs. The specimens were classified according to the treatment approach applied as follows: I; Sound enamel, Group II; artificially-created WSLs, Group III; ICON resin-restored WSLs, Group IV; Universal adhesive resin-restored WSLs, Group V; 0.5 wt% nHA-containing universal adhesive resin-restored WSLs, Group VI; 1 wt% nHA-containing universal adhesive resin- restored WSLs, and Group VII; 3 wt% nHA-containing universal adhesive resin-restored WSLs, Group VIII; 5 wt% nHA-containing universal adhesive resin-restored WSLs, Group IX; 7 wt% nHA-containing universal adhesive resin-restored WSLs, and Group X; 10 wt% nHA-containing universal adhesive resin-restored WSLs. Some surface characteristics and color changes were assessed. Data was collected and analyzed statistically using ANOVA and the Tukey test at p < 0.05.

RESULTS

Surface microhardness of WSLs was significantly improved with all investigated ratios of nHA-containing universal adhesive (p < 0.0001), with the highest mean belonging to 10 wt% nHA-containing universal adhesive resin treated WSLs. All ratios of nHA-containing universal adhesive resin significantly reduced the surface roughness of WSLs (p < 0.0001). The investigated ratios of 1, 3, 5, 7, and 10 wt% nHA-containing universal adhesive resin treatment approach could mask the WSLs significantly (p < 0.0001).

CONCLUSIONS

Nano-hydroxyapatite-containing universal adhesive is a promising contemporary approach for the management of WSLs, coupled both the remineralizing concept and the minimally invasive resin infiltration.

Evaluation of the Effect of NovaMin and Er,Cr:YSGG Laser on Remineralization of Erosive Lesions of Primary Enamel Teeth: An In Vitro Study

Introduction: The purpose of this in vitro study is to ascertain how NovaMin and Er,Cr:YSGG laser radiation affect the remineralization of primary tooth enamel lesions. Methods: 40 main teeth served as the study's sample size. These teeth were allocated into five groups at random. The first group served as a negative control (artificial saliva); the second group served as a positive control (APF gel 1.23%); the third group NovaMin, the fourth group Er,Cr:YSGG laser, the fifth group Er,Cr:YSGG laser and finally, the application of NovaMin. For the purpose of measuring microhardness, all samples were submitted to the dental materials laboratory three times. Results: The collected data were compared using the SPSS 28 program between the baseline measurement, after demineralization, and after remineralization. The data were analyzed using ANCOVA and Bonferroni tests. All groups demonstrated a considerable increase in microhardness as compared to the negative control group (P<0.05). With the exception of the third and fourth groups, there was no discernible difference in the rise in microhardness between the other groups. The third and fourth groups were compared, and the results revealed that NovaMin had a greater impact than laser therapy alone (P=0.023). Scanning electron microscopy (SEM) analysis backed up the findings. Conclusion: In comparison to using the Er,Cr:YSGG laser alone, using NovaMin alone can speed up the remineralization of erosion lesions on the surface of primary teeth.

Effect of the association of microparticles and nano-sized β-calcium glycerophosphate in conventional toothpaste on enamel remineralization: In situ study

OBJECTIVES

This in situ study aimed to assess the remineralizing effect of a fluoride toothpaste supplemented with β-calcium glycerophosphate in both micro (β-CaGPm) and nano-sized forms (β-CaGPn).

METHODS

This blind and cross-over study was performed in 4 phases, each spanning 3 days. Twelve volunteers utilized palatal appliances containing four bovine enamel blocks with artificial caries lesions. Volunteers were randomly assigned to the following treatment groups: Placebo (no F-β-CaGPm-β-CaGPn); 1100 ppm F alone (1100F); 1100F plus 0.5% micrometric β-CaGP (1100F-0.5%β-CaGPm); and 1100F plus 0.25%nano-sized β-CaGP (1100F-0.25%β-CaGPn). Participants were instructed to brush their natural teeth with the palatal appliances in the mouth for 1 min (3 times/day), ensuring that the enamel blocks were exposed to the natural toothpaste slurries. Following each phase, evaluations were conducted to determine the percentage of surface hardness recovery (%SHR), integrated recovery of subsurface hardness (ΔIHR), profile subsurface lesion through polarized light microscopy (PLM), as well as fluoride (F), calcium (Ca), and phosphorus (P) concentrations within the enamel. Data were analyzed by ANOVA and Student-Newman-Keuls test (p < 0.001).

RESULTS

Treatment with 1100F-0.25%β-CaGPn resulted in %SHR ∼69 % and ∼40 % higher when compared to 1100F and 1100F-0.5%β-CaGPm (p < 0.001). The reduction in lesion body (ΔIHR; PLM) was ∼40 % higher with 1100F-0.25%β-CaGPn (p < 0.001) compared to 1100F. The addition of β-CaGPm and β-CaGPn did not influence enamel F concentration (p > 0.001). Treatment with 1100F-0.25%β-CaGPn led to an increase in the concentration of Ca and P in the enamel (p < 0.001).

CONCLUSION

The addition of 0.25%β-CaGPn into 1100F formulation increased the bioavailability of calcium and phosphate, promoting a higher remineralizing effect.

CLINICAL SIGNIFICANCE

Toothpaste containing 1100F-0.25%β-CaGPn showed a potential of higher remineralization to 1100 ppm F and 1100 ppm F micrometric β-CaGP could be a strategy for patients at caries activity.

Multifunctional magnesium organic framework-based photothermal and pH dual-responsive mouthguard for caries prevention and tooth self-healing promotion

Caries is considered to be the most prevalent non-communicable disease in humans, mainly deriving from acidogenic bacterial biofilm and resulting in the demineralization and decomposition of hard dental tissue. Herein, a composite responsive foam brace loaded with magnesium organic framework (MPC) is designed for caries prevention and tooth remineralization. MPC can intelligently release organic antibacterial molecules (gallic acid) and mineralized ions (Mg²⁺, Ca²⁺ and PO₄^3-) under acidic conditions (pH < 5.5) of biofilm infection, regulating pH and killing bacteria. Additionally, due to the excellent photothermal conversion efficiency, MPC can further enhance the destruction of bacterial biofilm by inhibiting virulence genes and destroying bacterial adhesion under near-infrared light irradiation (808 nm). More importantly, MPC can not only reverse the cariogenic environment at both pH and microbial levels, but also promote self-healing of demineralized teeth in terms of both the micro-structure and mechanical properties.

Synthesis and characterization of hydroxyapatite nanoparticles and their effects on remineralization of demineralized enamel in the presence of Er,Cr: YSGG laser irradiation

BACKGROUND

This study aims to synthesize and characterize hydroxyapatite nanoparticles (nano-HA) and evaluate their effects on the remineralization of demineralized enamel in the presence to Er,CR: YSGG laser irradiation.

MATERIALS AND METHODS

Enamel specimens from 44 human molars were divided into four groups: control, demineralized enamel, demineralized enamel treated with nano-HA, and demineralized enamel treated with nano-HA followed by Er,Cr:YSGG laser irradiation (0.5, 20 Hz, 60 µs, 20 s). Vickers microhardness test was used to evaluate the enamel surface hardness. The morphology and chemistry of enamel surfaces were assessed using scanning electron microscopy (SEM) and Raman spectroscopy, respectively.

RESULT

The result of this study showed that the application of Er,CR: YSGG laser irradiation to demineralized enamel treated with nano-HA had the highest impact on its microhardness.

CONCLUSION

ER,CR: YSGG laser irradiation promotes enamel remineralization after treatment with nano HA.

Comparative evaluation of four treatments for postorthodontic white spot lesions: a randomized controlled trial

OBJECTIVES

To evaluate the treatment efficacy of fluoride toothpaste alone and those of adjunctive use of resin infiltration, sodium fluoride varnish, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on white spot lesions (WSLs).

MATERIALS AND METHODS

Seventy-nine patients (356 teeth) with WSLs after orthodontic treatment were randomly allocated into four groups. The WSLs of the participants received resin infiltration only at baseline, and the other groups received fluoride varnish, CPP-ACP mousse, and placebo treatment every 6 months, respectively. A toothpaste containing 1400 ppm fluoride and toothbrushes were distributed to all participants, and oral hygiene instructions were provided. Photos of the teeth with WSL were taken to compare the change between groups which was measured by ImageJ software.

RESULTS

Twelve months later, different degrees of reduction in the area of WSLs were observed in all groups. The percentage of lesion area reduction in WSLs in the resin infiltration group was 46.6%, which was significantly higher than that in fluoride varnish group (26.6%), CPP-ACP group (28.6%), and control group (29.8%), and the differences were statistically significant (p < 0.001).

CONCLUSIONS

This study shows that after 1-year follow-up, the use of fluoride toothpaste, with or without the use of fluoride varnish or CPP-ACP, can reduce the area of WSLs. While resin infiltration can immediately improve dental aesthetics and continuously improved in 12 months, resin infiltration group showed much better results than other groups.

TRIAL REGISTRATION

Clinical Trials Registration Number: ChiCTR2000032516.

CLINICAL SIGNIFICANCE

The use of fluoride toothpaste, with or without adjunctive use of fluoride varnish and CPP-ACP, can reduce the area of WSLs, while resin infiltration treatment has additional effect and can immediately improve dental aesthetics.

A novel orthodontic adhesive containing zinc-doped phosphate-based glass for preventing white spot lesions

OBJECTIVES

This study aimed at demonstrating the remineralization effect of the enamel around the brackets to aid reduction in white spot lesions (WSLs) with use of zinc-doped phosphate-based glass (Zn-PBG) containing orthodontic adhesives.

METHODS

Zn-PBG powder was synthesized, and particle morphology, size, and density were evaluated. Orthodontic adhesives with increasing loading percentage of Zn-PBG powder were prepared: ZnPG3 (3 wt.%), ZnPG6 (6 wt.%), and ZnPG9 (9 wt.%). Brackets were bonded on the etched enamel surface and stored in distilled water (DW) for 1 h. Following, Shear bond strength (SBS) along with adhesive remnant index were analyzed. The release of calcium (Ca), phosphorus (P), and zinc (Zn) from adhesive specimens in DW was evaluated after 7, 15 and 30 days of immersion. The remineralization effect was confirmed by microhardness and surface morphology analysis with scanning electron microscopy.

RESULTS

The SBS value was observed between 20 and 22 MPa on enamel surface. The concentration of Ca, P and Zn released in DW increased with loading percentage of Zn-PBG. The microhardness increased in the experimental groups after immersion in artificial saliva for 7 days. Apatite-like crystal formation was observed after 30 days in the ZnPG 9 group.

CONCLUSIONS

The orthodontic adhesive containing Zn-PBG with an optimal SBS performance has an enamel remineralization effect, and therefore can aid in prevention of WSLs.

CLINICAL SIGNIFICANCE

The orthodontic adhesive containing Zn-PBG is clinically advantageous as it can promote remineralization and resist the formation of WSLs that may occur during orthodontic therapy.

Fluoride Varnish in Dentistry: A Bibliometric Analysis of the 100 Most-Cited Papers

A highly cited paper is a milestone and might impact research and clinical practice. The present study analyzed the 100 most-cited papers on fluoride varnishes in dentistry. A search was performed on July 20, 2022, on the Web of Science Core Collection. Two independent researchers extracted the following data: number and citation density; year and journal of publication; study design; main topic; authors; institutions; keywords; countries and continents. Scopus and Google Scholar were consulted to compare the number of citations. Bibliometric networks were generated in the VOSviewer. The number of citations ranged from 36 to 351, and thirteen papers were cited more than 100 times. The papers were published between 1977 and 2018, most of which were published after 2008 (48%). The most prevalent journal was Caries Research (17%). Intervention studies were the most common design (41%). The most discussed topics were dental caries prevention (48%) and dental remineralization (31%). Europe was the continent with the highest number of publications (46%), mainly from Sweden (14%), and Umea University had the most substantial number of studies (8%). Petersson L.G. was the author with more papers in the top 100 (6%). The most used keywords were "dental caries" (34%) and "fluoride varnish" (31%). It can be concluded that the top 100 cited papers on fluoride varnish primarily originated from Europe, with the majority consisting of intervention studies focusing on the utilization of fluoride varnish for the prevention of dental caries.

Effectiveness of MI Varnish™ and PreviDent® Varnish in Noncavitated Interproximal Lesions: A Randomized Clinical Trial

Aim

Evaluating the remineralization efficacy of noncavitated proximal incipient lesions with Colgate® PreviDent® and MI™ varnishes in comparison to the industry standard (1.23%) acidulated phosphate fluoride (APF) gel.

Study design

Parallel randomized controlled, multicenter, single-blinded trial.

Materials and methods

By flipping a coin, 18 patients with 91 lesions were divided into three groups. The Colgate® PreviDent (n = 33), MI varnish (n = 30), and control (APF gel) groups (n = 28) were identified as the three arms. We conducted an initial assessment and therapy as well as follow-ups at 3 and 6 months to evaluate the course of the caries lesion.

Results and statistics

Caries progression was significantly reduced on treated surfaces across both groups. Nine surfaces in the Colgate® PreviDent® group with white spots and dryness did not change, one surface turned into a white patch without dryness, and another surface changed to a sound surface; only two surfaces were discontinued from treatment (restored) due to a misdiagnosis by the operator (n = 2). Nine of the surfaces in the MI™ group maintained their white patches with dryness, whereas one developed a new white patch that was not dry. Only MI varnish™-treated teeth exhibited dramatic radiographic improvement. Caries on the outside enamel were either unchanged or restored to healthy levels. Caries on the inner surface of the enamel also did not change.

Conclusion

Remineralizing noncavitated early-stage lesions may be done with both MI™ and Colgate® PreviDent® varnishes. Despite this, radiographic results did not vary significantly across the three groups. In situations of rather advanced incipient caries seen on radiographs, the MI varnish™ might be recommended.

How to cite this article

Helal N, Azzahrani GS, Azzouz LZ. Effectiveness of MI VarnishTM and PreviDent® Varnish in Noncavitated Interproximal Lesions: A Randomized Clinical Trial. Int J Clin Pediatr Dent 2023;16(5):751-757.

Nanohydroxyapatite in dentistry: A comprehensive review

Enamel, being the hardest and the highest mineralized tissue of the human body, contains nearly 96% inorganic components and 4% organic compounds and water. Dentin contains 65% inorganic components and 35% organic and water content. The translucency and white appearance of enamel are attributed to Hydroxyapatite (HA), which constitutes the major part of the inorganic component of dental hard tissue. With the advent of nanotechnology, the application of Nanohydroxyapatite (nHA) has piqued interest in dentistry due to its excellent mechanical, physical, and chemical properties. Compared to HA, nHA is found to have superior properties such as increased solubility, high surface energy and better biocompatibility. This is due to the morphological and structural similarity of nanosized hydroxyapatite particles to tooth hydroxyapatite crystals. These nanoparticles have been incorporated into various dental formulations for different applications to ensure comprehensive oral healthcare. To prevent dental caries, several nHA based dentifrices, mouth rinsing solutions and remineralizing pastes have been developed. nHA-based materials, such as nanocomposites, nano impression materials, and nanoceramics, have proven to be very effective in restoring tooth deformities (decay, fracture, and tooth loss). The nHA coating on the surface of the dental implant helps it bind to the bone by forming a biomimetic coating. A recent innovative strategy involves using nHA to reduce dentinal hypersensitivity and to reconstruct periodontal bone defects. The purpose of the present review is to discuss the different applications of nHA in dentistry, especially in preventive and restorative dentistry, dental implantology, bleaching and dentine hypersensitivity management.

Evaluation of Iontophoresis as a Tool in Comparison to Topical Remineralization Systems by Transverse Microradiography and Polarized Light Microscopy: An In Vitro Study

Aim

To compare the efficacy of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (GC Tooth Mousse) and tricalcium phosphate formulation (Clinpro) by topical application and iontophoresis.

Background

Noninvasive treatment of dental caries is a major advance in the clinical management of the disease.

Materials and methods

A total of 20 primary anterior and 20 primary molars were included in the study to be analyzed by transverse microradiography (TMR) and polarized light microscopy (PLM). The samples were coated with acid-resistant varnish, leaving a window on the buccal/lingual surface of enamel and immersed in demineralizing solution for 96 hours. Each sample was coated with varnish on the left half (control), and the right half served as a test. All the samples were divided into four groups. The test windows of specimens in groups I (GC Tooth Mousse) and II (Clinpro) were subjected to remineralization treatments for 10 days. Similarly, groups III and IV were subjected to iontophoresis using GC Tooth Mousse and Clinpro for 7 minutes. The samples were analyzed by TMR and PLM.

Results

There was no significant difference in the mean difference of mineral loss among the four groups. There was a significant difference in the mean difference of lesion depth among the four groups.

Conclusion

Both iontophoresis and topical application were equally efficient, but one remineralization by iontophoresis equals 10 topical applications.

How to cite this article

VC R, Muppa R, Nallanchakrava S, et al. Evaluation of Iontophoresis as a Tool in Comparison to Topical Remineralization Systems by Transverse Microradiography and Polarized Light Microscopy: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-1):S85-S90.

Comparative evaluation of fluoride-free remineralization agents with and without Er,Cr:YSGG laser on artificial enamel remineralization

This study aimed to evaluate the efficacy of fluoride-free remineralizing agents in initial enamel caries, with and without combined Er,Cr:YSGG laser application. The remineralization effect of various agents and their combinations on artificial initial caries was investigated using 10 experimental groups (n = 7): NC, negative control; PC, positive control; TM, calcium-phosphate compounds (CPP-ACP); TD, theobromine-containing toothpaste; RG, ROCS® remineralizing gel; L, Er,Cr:YSGG laser (2780 nm; 0.25 W; repetition rate, 20 Hz; pulse duration, 140 μs; tip diameter, 600 μm; without air/water cooling); L + fluoride toothpaste; L + TM; L + TD; and L + RG. The demineralized bovine enamel specimens were subjected to an 8-day pH cycle by daily application of the remineralizing agents and laser therapy once prior to the pH cycle and paste application. The enamel samples underwent the Vickers surface microhardness test, and one sample per group was analyzed with scanning electron microscopy. The Kruskal Wallis test was used to compare the microhardness recovery percentage (SMHR%) for each group, and multiple comparisons were made with the Dunn test. Groups L (p = 0.003), RG (p = 0.019), L + TM (p < 0.001), L + fluoride toothpaste (p = 0.001),and L + RG (p = 0.036) exhibited significant increase in SMHR%. The tested remineralizing agents exhibited no statistically significant difference in effect when used alone and in combination with Er,Cr:YSGG laser. Combined application of Er,Cr:YSGG laser and ROCS® remineralization gel effectively promoted enamel remineralization, while use of CPP-ACP and fluoride toothpaste alone was ineffective. Theobromine-containing toothpaste exhibited the least SMHR%. Long-term evaluation of these agents is recommended.

Effect of Liquorice Candies on Remineralization of Initial Enamel Carious Lesion

Background

Glycyrrhiza glabra (G. glabra), known as liquorice root is one such herbal remedy that has been shown to have immense potential in the treatment of orofacial diseases.

Aim

To evaluate the remineralizing potential of liquorice extract on initial enamel carious lesions.

Materials and methods

An in vitro and in vivo study was conducted, wherein the sound-extracted human premolars were sectioned longitudinally and into enamel blocks of size 4 × 4 mm. Enamel blocks were demineralized to produce artificial carious lesions. In vitro study, the demineralized enamel block was exposed to artificial saliva for 5 minutes and artificial saliva containing liquorice for 4 minutes 14 times in a sequential manner. An in vivo study was carried out on six volunteers aged between 6 and 12 years. The demineralized enamel block was inserted into the 5 × 5 mm window created on the full palatal coverage appliance. Patients were given commercially available liquorice candies (Ricola) to consume for 7 days twice daily. The remineralization potential of liquorice on demineralized enamel block was assessed using confocal microscopy analysis.

Results

Liquorice extract containing candies showed visual remineralization of the demineralized area on the enamel surface through confocal images.

Conclusion

Liquorice extract possesses remineralizing potential with its other medicinal properties.  .

How to cite this article

Pooja HR, Nagar P, Mascarenhas AN, et al. Effect of Liquorice Candies on Remineralization of Initial Enamel Carious Lesion. Int J Clin Pediatr Dent 2023;16(S-1):S33-S38.

A Comparative Study of the Effect of Tooth Mousse Plus Remin Pro and Fluor Protector Gel on Enamel Erosion: An In Vitro Study

Background

The purpose of this in vitro study was to assess the effect of Tooth Mousse Plus, Remin Pro, and Fluor Protector Gel on enamel erosion, measuring mean weight loss after exposure to a demineralizing agent.

Materials and methods

A total of 60 sound-extracted permanent incisors were sectioned and enamel specimens were randomly distributed to different groups. The initial weight of all specimens was registered. The samples were randomly divided into four groups (n = 30). Group I specimens were treated with tap water (control). Groups II, III, and IV were treated with Tooth Mousse, Remin Pro, and Fluor Protector Gel application. After that, specimens were placed all together in a plastic container with 6 mL of a soft drink and immersed for 8 minutes at room temperature, dried, and weighed. Specimens were weighed after each immersion period and mean weight loss was calculated. The data was analyzed for probability distribution using the Kolmogorov-Smirnov test. The intergroup comparison was done using a one-way analysis of variance (ANOVA) followed by post hoc analysis.

Results

According to pairwise comparisons in post hoc analysis, the weight of specimens at baseline was significantly greater than the weight of specimens on day 12. The difference in the mean weight of the specimen from baseline to day 12 was 2.833 mg for group I, 2.367 mg for group II, 1.467 mg for group III, and 2.133 mg for group IV.

Conclusion

Tooth Mousse Plus, Remin Pro, and Fluor Protector Gel have no significant effect on dental erosion.

How to cite this article

Shukla K, Saxena A, Joshi J, et al. A Comparative Study of the Effect of Tooth Mousse Plus Remin Pro and Fluor Protector Gel on Enamel Erosion: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-1):S57-S62.

In vitro remineralization assessment of enamel subsurface lesions using different percentages of surface reaction-type pre-reacted glass-ionomer containing gum-based material

OBJECTIVE

To identify the remineralization activity of enamel subsurface lesions using different percentages of surface pre-reacted glass-ionomer (S-PRG) filler containing gum-base material.

METHODS

Gum extracts from gum-base materials containing 0wt%, 5wt%, and 10wt% S-PRG filler were prepared as GE0, GE5, and GE10, respectively. A total of 50 bovine enamel specimens were used, and the polished enamel surface of a 3 × 3 mm2 window area was exposed. The specimens were then subjected to a demineralization solution for seven days to create a subsurface enamel lesion. Remineralization was then conducted for seven days using a protocol whereby the specimens were immersed three times a day in prepared gum extracts (0wt%, 5wt%, and 10wt%) and artificial saliva of pH 7 (Control) for 20 min at 37 °C. Thereafter, remineralization assessment was performed by using Swept Source Optical Coherence Tomography (SS-OCT) and micro-computed tomography (μCT). Surface morphology and elemental analysis were conducted by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS).

RESULTS

The depths of the demineralized lesions in the GE5 and GE10 groups were significantly lower than those of the Control and the GE0 groups. SEM observations of the enamel surface morphology of the GE5 and GE10 groups indicated remineralization with S-PRG filler-related elements present.

CONCLUSION

The GE5 and GE10 S-PRG filler containing gum-base materials showed significantly improved surface remineralization and reduced demineralization of the enamel lesions. EDS analysis suggested that the released ions from the S-PRG filler might be responsible for surface remineralization.

CLINICAL SIGNIFICANCE

The S-PRG filler containing gum-base material may have a significant remineralization effect and improve the surface morphology of enamel subsurface lesions.

Theobromine versus casein phospho-peptides/Amorphous calcium phosphate with fluoride as remineralizing agents: effect on resin-dentine bond strength, microhardness, and morphology of dentine

BACKGROUND

This study aimed to assess the impact of theobromine and casein phospho-peptides/amorphous calcium phosphate with fluoride (CPP-ACPF) on the resin-dentine bond strength, microhardness, and dentine morphology.

METHODS

A total of 18 sound human molars for micro-tensile bond strength (µTBS), 20 sound human premolars for microhardness, and 30 premolars for Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) were used. Based on the pre-treatment used, teeth were split into six groups; sound dentine, demineralized dentine, and demineralized dentine treated with theobromine (Sigma Aldrich) and MI paste plus (GC International, USA) for two-time intervals; 5 min and 1 month. The bonded teeth were sectioned to produce 1 mm² resin-dentine sticks which were evaluated for µTBS using a universal testing device (Instron 3365, USA). The dentine microhardness was tested by using the Vickers microhardness tester (Nexus 4000 TM, Netherlands). The pre-treated dentine surface was examined using SEM/EDX (Neoscope JCM-6000 plus Joel benchtop SEM, Japan). µTBS results were analysed with two-way ANOVA. Microhardness and EDX results were analysed with two-way mixed model ANOVA. The significance level was set at (p ≤ 0.05).

RESULTS

While both remineralizing materials at the two-time intervals demonstrated µTBS comparable to sound dentine (46.38 ± 12.18), the demineralized group demonstrated statistically the lowest µTBS (p < 0.001). Whether used for 5 min or 1 month, theobromine significantly increased the microhardness (50.18 ± 3.43) and (54.12 ± 2.66) respectively (p < 0.001), whereas MI paste only increased the hardness (51.12 ± 1.45) after 1 month (p < 0.001).

CONCLUSIONS

The pre-treatment of demineralized dentine with theobromine for 5 min or 1 month could enhance its bond strength and microhardness while for MI paste plus, only 1-month application was efficient to ensure remineralization.

Recent advances on nanomaterials for antibacterial treatment of oral diseases

An imbalance of bacteria in oral environment can lead to a variety of oral diseases, such as periodontal disease, dental caries, and peri-implant inflammation. In the long term, in view of the increasing bacterial resistance, finding suitable alternatives to traditional antibacterial methods is an important research today. With the development of nanotechnology, antibacterial agents based on nanomaterials have attracted much attention in dental field due to their low cost, stable structures, excellent antibacterial properties and broad antibacterial spectrum. Multifunctional nanomaterials can break through the limitations of single therapy and have the functions of remineralization and osteogenesis on the basis of antibacterial, which has made significant progress in the long-term prevention and treatment of oral diseases. In this review, we have summarized the applications of metal and their oxides, organic and composite nanomaterials in oral field in recent five years. These nanomaterials can not only inactivate oral bacteria, but also achieve more efficient treatment and prevention of oral diseases by improving the properties of the materials themselves, enhancing the precision of targeted delivery of drugs and imparting richer functions. Finally, future challenges and untapped potential are elaborated to demonstrate the future prospects of antibacterial nanomaterials in oral field.

Comparison of therapies of white spot lesions: a systematic review and network meta-analysis

OBJECTIVE

White spot lesions (WSLs), the earliest evidence of enamel demineralization, are considered amenable to intervention to achieve a remineralized or arrested state of caries. The management of WSLs is quite challenging, and there is no definitive cure as yet. We performed a network meta-analysis to assess the efficacy of seven therapies for WSLs and gave a hierarchy of them.

MATERIALS AND METHODS

We systematically searched the PubMed, EMBASE, Cochrane, and Web of Science databases (last search: July 2022) to identify all relevant studies. We limited our search to studies published in English. Randomized controlled designed in vitro/clinical trials related to the efficacy of the seven therapies for WSLs were included. Data extraction was performed independently by two reviewers. The risk of bias (ROB) 2.0 tool from Cochrane and a previous in vitro methodological tool will be used for the quality assessment. Variations in quantitative light-induced fluorescence (QLF), laser fluorescence (LF), and lesions area were the primary outcome measures. Standard mean difference (SMD) was used as the effect size for the Network meta-analysis (NMA). Consistency and inconsistency tests were conducted. The hierarchy of 7 treatment effects was evaluated using surface probabilities under cumulative ranking (SUCRA). Publication bias was evaluated using a bias plot.

RESULTS

Forty-two articles were included in the systematic review. Thirty-one of them, with a total of 1906 participants, were included in the network meta-analysis. The studies owned a low and moderate risk of bias. This analysis does not suffer from significant inconsistency. The difference between 4 groups 'self-assembled peptide (SAP) P11-4', 'P11-4 + Fluoride Varnish (FV)', 'Resin Infiltration (RI)', 'casein phosphor peptides-amorphous calcium fluoride phosphate (CPP-ACFP)' and the 'Control' group was found to be statistically significant. Compared to the 'FV' and 'casein phosphor peptides-amorphous calcium phosphate (CPP-ACP)' groups, the 'P11-4 + FV" group and 'RI" group made a significant difference. The hierarchy was evident in the SUCRA values of 7 therapies. P11-4 + FV and RI were considered effective therapies compared to the control group or the FV group (gold standard group).

CONCLUSIONS

The available evidence suggests that resin infiltration and P11-4 in combination with fluoride varnish had advantages over gold standard (FV). The effect of tricalcium phosphate-based drugs and fluoride is not very noticeable. Overall, drugs based on P11-4 and resin infiltration will be better therapies. Using more than two drugs in combination also would increase efficacy.

Effect of Casein Phosphopeptide-Amorphous Calcium Phosphate Added to Milk, Chewing Gum, and Candy on Dental Caries: A Systematic Review

Casein is one of the most studied proteins with activity against dental caries. In particular, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) has shown promising remineralizing properties. In vivo evidence on the anticaries potential of CPP-ACP added to foodstuffs is elusive, nonetheless. Hence, this systematic review aimed at determining whether the use of CPP-ACP added to foodstuffs has a remineralizing or inhibitory action on dental demineralization either in vivo or in situ. The review protocol followed the PRISMA-P criteria and was registered in PROSPERO. PubMed, Scopus, and Web of Science databases were searched using predefined criteria, based on the PICO question: Is there an effect on dental caries upon adding CPP-ACP to milk, chewing gums, or candies? No year or language limits were applied. Article selection and data extraction were carried out independently by 2 investigators. Two hundred ten titles were examined, 23 were selected for full-text review, and 16 studies were included (2 in vivo and 14 in situ). CPP-ACP was added to candy in 2 studies, to milk in 2 studies, and to chewing gum in 12 studies. The main outcomes included enamel remineralization and activity against dental biofilm. The overall quality of the evidence was classified as moderate. The available evidence suggests that CPP-ACP added to milk, chewing gum, or candy has a potential remineralizing activity on tooth enamel, with some additional antibacterial activity on the dental biofilm. Further clinical studies are needed to verify if this effect is clinically significant in reducing the caries lesion incidence or to revert the demineralizing process.

Development of a bioactive dentin adhesive resin modified with magnesium-doped synthetic hydroxyapatite crystals

The aim is to evaluate the development of an experimental multi-mode/Universal resin-based dentin adhesive modified with synthetic Mg²⁺ doped hydroxyapatite crystals (HAp) having self-remineralization and antibiofilm properties. HAp doped with Mg²⁺ was prepared by the precipitation method. Experimental adhesives were subjected to degree of conversion and X-ray diffraction test for size and crystal structure. Bond strength was tested, and electron microscopy (SEM/TEM) imaging of resin-dentin interface was done along with nanoleakage, nanoindentation, confocal and Raman analyses. S. mutans was analysed using CLSM images against modified adhesive specimens. Nucleating abilities within the resin-dentin specimens are determined by measuring Ca²⁺. Alkaline phosphatase, Runx2, and Ocn transcripts are amplified using quantitative polymerase chain reaction (q-PCR). A calcium assay is performed to quantify level of mineralisation. When compared to control adhesives, the 0.5% Hap/Mg²⁺ containing experimental dentin adhesive demonstrated improved interaction with dentin. The preservation of uniform intact hybrid layer with the absence of nanoleakage indicated dentin bond integrity with 0.5% HAP/Mg²⁺ modified adhesive. Self-remineralization and antibiofilm potentials are supported.

Recent advances in the use of inorganic nanomaterials as anti caries agents

Caries is the most prevalent and widespread chronic oral disease. Traditional caries filling materials, due to their lack of anti-caries capabilities, can readily develop secondary caries. Nanomaterials proposed as an effective approach for caries treatment can inhibit biofilm formation. It also can not only reduce demineralization but also promote remineralization. In recent years, nanotechnology in anti-caries materials, particularly nano-adhesive and nano-composite resin, has advanced rapidly. Because inorganic nanoparticles (NPs) interfere with bacterial metabolism and inhibit biofilm development, inorganic NPs have emerged as a new trend in dental applications. Metal and metal oxide NPs by releasing metal ions, oxidative stress induction, and non-oxidative mechanisms showed significant antimicrobial activity. For applying metal and metal oxide NPs as anti caries agents, silver, zinc, titanium, copper, and calcium ions have been shown significant attention. Moreover, fluoride functionalized inorganic NPs were also employed to improve their efficacy of them. The fluoride-functionalized NPs can promote remineralization, and inhibit demineralization by enhancing apatite formation. In this review, we have provided an overview and recent advances in the use of inorganic NPs as anti caries agents. Furthermore, their antimicrobial, remineralizing, and mechanical impacts on dental materials were discussed.

Remineralization of lytic spinal metastases after radiotherapy

BACKGROUND CONTEXT

Palliative radiotherapy (RT) can lead to remineralization of osteolytic lesions thereby potentially restoring some of the weight-bearing capacity and preventing vertebral collapse. It is not clear, however, under which circumstances remineralization of osteolytic lesions occurs.

PURPOSE

The aim of this study was to investigate the change in bone mineral density in spinal metastases after RT compared to a reference region, and find associated factors.

STUDY DESIGN

Retrospective analysis within prospective observational cohort OUTCOME MEASURES: change in bone mineral density measured in Hounsfield Units (HU).

PATIENT SAMPLE

patients treated with RT for (painful) bone metastases.

METHODS

Patients with spinal metastases were included if computed tomography scans both pre- and post-RT were available. Bone density was measured in HU. A region of interest (ROI) was drawn manually in the metastatic lesion. As a reference, a measurement of bone density in adjacent, unaffected, and non-irradiated vertebrae was used. Factors tested for association were origin of the primary tumor, RT dose and fractionation scheme, and concomitant use of bisphosphonates.

RESULTS

A total of 31 patients with 49 spinal metastases, originating from various primary tumors, were included. The median age on baseline was 58 years (IQR: 53-63) and median time between baseline and follow-up scan was 8.2 months (IQR: 3.0-18.4). Difference in HU in the lesion before and after treatment was 146.9 HU (95% CI 68.4-225.4; p<.01). Difference in HU in the reference vertebra between baseline and first follow-up was 19.1 HU (95% CI -47.9 to 86.0; p=.58). Difference between reference vertebrae and metastatic lesions on baseline was -194.1 HU (95% CI -276.2 to -112.0; p<.01). After RT, this difference was reduced to -50.3 HU (95% CI -199.6 to 99.0; p=.52). Patients using bisphosphonates showed a greater increase in HU, 194.1 HU versus 60.6 HU, p=.01.

CONCLUSIONS

Palliative radiation of osteolytic lytic spinal metastases is positively associated with an increased bone mineral density at follow-up. The use of bisphosphonates was linked to an increased bone mineral density when used during or after RT.

Enhanced effect of a novel bioactive glass-ceramic for dental application

OBJECTIVES

Dental caries is the most common chronic disease in humans, caused by the acid produced by the microflora in the mouth that dissolves the enamel minerals. Bioactive glass (BAG) has been used in various clinical applications due to its unique bioactive properties, such as bone graft substitutes and dental restorative composites. In this study, we introduce a novel bioactive glass-ceramic (NBGC) prepared through a sol-gel process under a water-free condition.

MATERIALS AND METHODS

The anti-demineralization and remineralization effects of NBGC were evaluated by comparing the measurements of bovine enamel surface morphology, surface roughness, surface micro-hardness, enamel elements, and mineral content before and after related treatments with a commercial BAG. The antibacterial effect was characterized by minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC).

RESULTS

Results showed that NBGC had greater acid resistance and remineralization potential compared to commercial BAG. The fast formation of a hydroxy carbonate apatite (HCA) layer suggests efficient bioactivity.

CLINICAL RELEVANCE

In addition to its antibacterial properties, NBGC shows promise as an ingredient in oral care products that can prevent demineralization and restore enamel.

Evaluation of Remineralization Potential of Natural Substances on Artificially Induced Carious Lesions in Primary Teeth: An In Vitro Study

Aim

To evaluate the remineralizing potential of natural substances on artificially induced caries lesions in primary teeth.

Materials and methods

A total of 50 primary molar teeth were selected and subjected to a demineralization process. Then samples were randomly divided into five groups for the remineralization process. Group I-colophony, group II-5% sodium fluoride (NaF) + colophony, group III-grape seed extract (GSE) + colophony, group IV-5% NaF + colophony + 10% peptide, and group V- GSE + colophony + 10% peptide. All the groups were subjected to remineralization using a brushing stimulator for 3,000 cycles. Assessment was done using Vickers hardness testing machine for evaluating the enamel surface microhardness (SMH) and scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX) for evaluating the surface morphology and mineral content, before and after demineralization and after remineralization, the obtained data was analyzed statistically using IBM Statistical Package for the Social Sciences (SPSS) software version 25.

Results

The enamel microhardness results of this study revealed that remineralization of enamel was highest in group V (212.83 ± 64.416) and least in group II (137.83 ± 26.324) p-value of 0.038. SEM-EDX analysis revealed high calcium (Ca) and fluoride (F) content in groups II and IV, which was significant (p-value of 0.001) from other groups. Surface morphology evaluated with SEM revealed spherical globular agglomerates and scaffolding deposits on the enamel surface in groups III and V resembling the remineralization process.

Conclusion

Grape seed extract (GSE) with colophony and peptide is a superior natural alternative to NaF. Colophony also exhibited remineralizing potential in primary enamel.

Clinical significance

Natural remineralizing agents like GSE, colophony, and its combination serves as a potential alternative to overcome the toxic effect on long-term usage of F. These natural substances can be applicable in clinical conditions by incorporating toothpaste and varnish, which can be used as an alternative or adjuvant to the topical application of F.

How to cite this article

Pooja V Ravi, Rajakumar S, Kavitha Ramar. Evaluation of Remineralization Potential of Natural Substances on Artificially Induced Carious Lesions in Primary Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(2):244-250.

Dexamethasone-doped nanoparticles improve mineralization, crystallinity and collagen structure of human dentin

OBJECTIVES

Bioactive materials have been used for functionalization of adhesives to promote dentin remineralization. This study aims to evaluate bonding ability and both mechanical and chemical behavior of demineralized dentin infiltrated with polymeric nanoparticles doped with dexamethasone (Dex-NPs).

METHODS

Dentin conditioned surfaces were infiltrated with NPs, Dex-NPs or Dex-Zn-NPs. Bonded interfaces were also created and stored for 24 h or 21d, and then submitted to microtensile bond strength testing. Dentin remineralization was analyzed by Nanohardness, Young's modulus and Raman analysis.

RESULTS

At 21d of storage, dentin treated with undoped-NPs attained the lowest nanohardness and Young's modulus. Dex-NPs and Zn-Dex-NPs increased dentin nanohardness and Young's modulus after 21d Raman analysis showed high remineralization, crystallinity, crosslinking and better structure of collagen when functionalized Dex-NPs were present at the dentin interface.

CONCLUSIONS

Infiltration of dentin with Dex-NPs promoted functional remineralization as proved by nanomechanical and morpho-chemical evaluation tests. Dexamethasone in dentin facilitated crystallographic maturity, crystallinity and improved maturity and secondary structure of dentin collagen.

CLINICAL SIGNIFICANCE

Using dexamethasone-functionalized NPs before resin infiltration is a clear option to obtain dentin remineralization, as these NPs produce the reinforcement of the dentin structure, which will lead to the improvement of the longevity of resin restorations.

Evaluation of shear bond strength and enamel remineralizing effect of experimental orthodontic composite containing nano-hydroxyapatite: An in vitro study

OBJECTIVE

The purpose of this study was to prepare an orthodontic composite containing hydroxyapatite nanoparticles to prevent demineralization and create a suitable environment for mineral deposition around orthodontic brackets, and to investigate the mechanical and remineralizing properties of the experimental adhesive composite.

METHODS

Experimental orthodontic composite were formulated using varying percentages of nano-hydroxyapatite particles. Assessments were based on four groups: a control group (3M™ Transbond™ XT) and experimental composites containing 2% (HA2), 5% (HA5) and 10% (HA10) hydroxyapatite. Vickers Microhardness test was performed to investigate the remineralizing effect in 3 stages: initial stage, after demineralization and after 4 weeks of exposure to artificial saliva. Scanning electron microscopy with energy dispersive X-ray spectroscopy analyser (SEM/EDAX) was used to evaluate hydroxyapatite precipitation and elemental composition of enamel surface. Shear Bond Strength tests were carried out using a universal testing machine and the debonding pattern was assessed using Adhesive Remnant Index (ARI).

RESULTS

All groups showed clinically acceptable SBS values. The highest SBS was achieved in the HA2 group, followed by Transbond™ XT, HA5 and HA10. There was no significant difference in the ARI scores. In terms of microhardness properties, HA5 and HA10 demonstrated a significant increase after 4 weeks. The results of SEM analysis showed the precipitation of hydroxyapatite crystals and EDAX analysis indicated the increase of calcium and phosphate ion peaks compared to the demineralized sample. The data were analysed using one-way ANOVA and Tukey's Post-hoc test.

CONCLUSIONS

Addition of hydroxyapatite nanoparticles to orthodontic composite can increase the mineral content and microhardness of the adjacent enamel. However, increasing the amount of nanoparticles reduces shear bond strength in a decreasing trend. The above-mentioned findings showed that incremental increase of nanoparticles of HA can be incorporated in composite to a certain extent and limitations are determined by mechanical properties (SBS) required for bracket bonding.

Micro-Raman spectroscopy analysis of dentin remineralization using eggshell derived nanohydroxyapatite combined with phytosphingosine

The aim of this study was to assess the remineralization efficacy of chicken eggshell-derived nano-hydroxyapatite (CEnHAp) combined with phytosphingosine (PHS) on artificially induced dentinal lesions. PHS was commercially procured whereas CEnHAp was synthesized using microwave-irradiation method and characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), high-resolution scanning electron microscopy-energy-dispersive X-ray spectroscopy (HRSEM-EDX), and transmission electron microscopy (TEM). A total of 75 pre-demineralized coronal dentin specimens were randomly treated with one of the following test agents (n = 15 each): artificial saliva (AS), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), CEnHAp, PHS, and CEnHAp-PHS under pH cycling for 7, 14, and 28 days. Vickers microhardness indenter, HRSEM-EDX, and micro-Raman spectroscopy methods were used to assess the mineral changes in the treated dentin samples. Data were submitted to Kruskal-Wallis and Friedman's two-way analyses of variance (p < 0.05). HRSEM and TEM analysis depicted irregular spherical structure of the prepared CEnHAp with a particle size of 20-50 nm. The EDX analysis confirmed the presence of Ca, P, Na and Mg ions. The XRD pattern showed the characteristic crystalline peaks for hydroxyapatite and calcium carbonate that are present in the prepared CEnHAp. Dentin treated with CEnHAp-PHS revealed highest microhardness values along with complete tubular occlusion compared to other groups at all test time intervals (p < 0.05). Specimens treated with CEnHAp showed increased remineralization than those treated with CPP-ACP followed by PHS and AS groups. The intensity of mineral peaks, as observed in the EDX and micro-Raman spectra, confirmed these findings. Further, the molecular conformation of the collagen's polypeptide chains, and amide-I and CH₂ peaks attained peak intensities in dentin treated with CEnHAp-PHS and PHS whereas other groups revealed poor stability of collagen bands. Microhardness, surface topography, and micro-Raman spectroscopy analyses revealed that dentin treated with CEnHAp-PHS have an improved collagen structure and stability as well as highest mineralization and crystallinity.

[Effects of novel bioactive glasses on promoting remineralization of artificial dentin caries]

OBJECTIVE

To investigate the effects of novel bioactive glasses (BG) including PSC with high phosphorus component and FBG with fluorine-doped element on promoting remineralization of artificial dentin caries.

METHODS

(1) BGs were used in this study as follows: PSC (10.8%P₂O₅-54.2%SiO₂-35.0%CaO, mol.%) were synthesized using phytic acid as the phosphorus precursor through sol-gel method. FBG (6.1%P₂O₅-37.0%SiO₂-53.9%CaO-3.0%CaF₂, mol.%) and 45S5(6.0%P₂O₅-45.0%SiO₂-24.5%CaO-24.5%Na₂O, mol.%) were synthesized by traditional melt method. (2) The above BGs were soaked in simulated body fluid (SBF) for 24 hours. Then X-ray diffraction (XRD) was used to analyze the formation of hydroxyapatite (HA) crystals. (3) Prepared 1 mm thick dentin slices were soaked in 17% ethylene diamine tetraacetic acid (EDTA) for 1 week to demineralize the dentin. Then the dentin slices treated by BG were soaked in SBF for 1 week. Field emission scanning electron micro-scopy (FE-SEM) was used to observe the surface morphology of the dentin slices. (4) Four cavities were prepared to 1 mm depth in each 2 mm thick dentin slice, then were treated with lactic acid for 2 weeks to form the artificial dentin caries. Wax, mineral trioxide aggregate (MTA), PSC and FBG were used to fill four cavities as blank control group, MTA group, PSC group and FBG group respectively. Then the spe-cimens were soaked in SBF for 4 weeks. The changes of depth and density of demineralized dentin were analyzed using Micro-CT before filling and after 2 and 4 weeks filling.

RESULTS

(1) PSC and FBG promoted mineral formation on the surfaces of the demineralized dentin. And the speed was faster and crystallinity was higher in PSC group than the FBG and 45S5 groups. (2) The increased mineral density of artificial dentin caries in PSC group were (185.98 ± 55.66) mg/cm³ and (213.64 ± 36.01) mg/cm³ 2 and 4 weeks after filling respectively, which were significantly higher than the control group [(20.38 ± 7.55) mg/cm³, P=0.006; (36.46 ± 10.79) mg/cm³, P=0.001]. At meanwhile, PSC group was also higher than MTA group [(57.29 ± 10.09) mg/cm³; (111.02 ± 22.06) mg/cm³], and it had statistical difference (P=0.015; P=0.006). The depth of remineralized dentin in PSC group were (40.0 ± 16.9) μm and (54.5 ± 17.8) μm 2 and 4 weeks respectively, which were also statistically different from the control group (P =0.010;P=0.001). There were no statistical differences between the control group and MTA group. The above effects of FBG group were between PSC and MTA.

CONCLUSION

PSC has advantages in the speed, quality and depth of mineral deposition in the demineralized layer of artificial dentin caries. It would be expected to be an ideal material to promote the remineralization of dentin caries.