State of the Art Enamel Remineralization Systems: The Next Frontier in Caries Management

Effects of Adding Tricalcium Silicate Nanoparticles to the Universal G2 Bond Adhesive as Self-Etch Mode on the Shear Bond Strength to the Orthodontic Bracket

OBJECTIVE

This study investigated the effects of adding tricalcium silicate nanoparticles (TCSNp) to the universal G2 bond adhesive (G2BU) in self-etch (SE) mode on shear bond strength (SBS) to orthodontic brackets, cytotoxicity, and degree of conversion (DC).

MATERIAL AND METHODS

A total of 176 human teeth were divided into four groups based on TCSNp concentration in G2BU adhesive: 0% (control), 1%, 3%, and 5%. The G2BU adhesive consists of a hydrophilic primer (P) and a hydrophobic bonding agent (2B). TCSNp were added to the 2B component by mixing 0.1, 0.3, and 0.5 g of TCSNp with 9.9, 9.7, and 9.5 g of 2B, respectively. SBS was assessed after 24 h of water storage and 5000 thermocycles using a universal testing machine. Cytotoxicity was evaluated using the MTT assay on rat embryo fibroblast cells, and DC was measured using fourier-transform infrared spectroscopy. Statistical analysis included one-way ANOVA and Tukey's post-hoc test, with significance set at p < 0.05.

RESULTS

After 24 h, mean SBS values were 15.58 MPa (control), 13.66 MPa (1% TCSNp), 15.99 MPa (3% TCSNp), and 12.04 MPa (5% TCSNp). After 5000 thermocycles, SBS values decreased to 12.91 MPa (control), 12.42 MPa (1% TCSNp), 11.11 MPa (3% TCSNp), and 10.21 MPa (5% TCSNp). ANOVA showed significant differences between groups (p < 0.05), except between the control and 3% TCSNp groups. Cell viability increased with higher TCSNp concentrations, with significant differences at 72 h between control and 5% TCSNp groups (p = 0.014). Mean DC values were 51.66% (control), 49.33% (1% TCSNp), 49.66% (3% TCSNp), and 48% (5% TCSNp). ANOVA indicated no significant differences between groups.

CONCLUSIONS

Adding TCSNp to G2BU in SE mode maintains clinically acceptable SBS levels and enhances cytocompatibility. Higher TCSNp concentrations may reduce SBS and DC slightly. Further studies are needed to evaluate long-term effects.

Surface porosity of enamel white spot lesions and penetration of fluorapatite nanocrystals into their subsurface: proof-of-concept study

OBJECTIVES

In this study, we used atomic force microscopy (AFM) to quantify the size of surface pore apertures of enamel white spot lesions and then demonstrated the penetration of fluorapatite nanocrystals (nFA) into the subsurface of these lesions.

METHODS

For the porosity study, enamel lesions were created on three sound human teeth using a demineralizing gel for 8 days. The interface between sound enamel and the artificial lesion was analyzed by AFM. To visualize the penetration of nFA tagged with a calcium-binding fluorophore (Fluo-4) into the subsurface of white spot lesions, we used two-photon microscopy. Sixteen extracted human teeth with either active, natural, or in vitro-created carious lesions in enamel were randomly divided into three groups. The teeth were treated for 2 min with either a suspension of tagged nFA crystals, Fluo-4 alone, or deionized water, and left for 30 min before being washed with distilled water and examined microscopically.

RESULTS

A greater concentration of surface pores with larger areas was observed on the in vitro demineralized enamel (29 % of pores greater than 1.0 µm2) when compared with the adjacent sound enamel (8 % of pores greater than 1.0 µm2) (p=0.012, Fisher exact test). In vitro and natural lesions treated with tagged nFA showed fluorescence at depths ranging from 50 to 170 µm, demonstrating penetration of the nFA into the lesion subsurface. The lesions treated with Fluo-4 alone with no crystals showed mostly surface fluorescence (restricted to the outer 25 µm), while those treated with deionized water showed minimal (restricted to the outer 20 µm) to no fluorescence.

CONCLUSION

We have demonstrated the use of AFM to quantify the surface pore apertures and two-photon microscopy to visualize nFA crystals in the subsurface of non-cavitated enamel lesions.

CLINICAL SIGNIFICANCE

The restoration of the subsurface of non-cavitated caries lesions is a clinical challenge. This study demonstrated that a 2 min application of nFA could penetrate through the surface apertures of non-cavitated enamel lesions into their subsurface.

Applications of smart materials in minimally invasive dentistry - some research and clinical perspectives

OBJECTIVES

Dental caries is one of the most prevalent bacteria-induced non-communicable diseases globally. It is known to be the top oral health burden in both developing and developed nations. There is substantial literature on the disease process and there is still debate on the extent of caries removal needed and the adequacy of the materials available to restore the lost tooth structure. The current review discusses the disease process together with the contemporary management of the carious lesion and also presents substantial evidence on novel materials and techniques that make minimally invasive dentistry predictable.

METHODS

The written work presented shows the most relevant literature for the management of dental caries focusing on novel materials used in minimally invasive dentistry.

RESULTS

There is still much to learn about specific antimicrobial and caries prevention mechanisms of novel materials. Materials that respond to a single or a few stimuli remain "weakly intelligent" in the face of the complex microenvironment in the oral cavity. Engineered systems that combine artificial intelligence and chemical engineering, are expected to possess higher intelligence, self-healing capabilities as well as environmental adaptability, and may be future promising research directions.

SIGNIFICANCE

The targeted approach in managing dental caries will hopefully have a better clinical outcome. The strategies discussed are alternatives to the contemporary approach and will improve the clinical management.

Evaluation of Mechanical and Elemental Properties of Bioceramic-Coated Orthodontic Brackets and Enamel Surface

OBJECTIVE

 The aim is to coat orthodontic brackets with two different bioactive materials and to compare the mechanical and morphological properties of coated brackets and tooth surfaces.

MATERIALS AND METHODS

 A total of 120 stainless steel brackets were divided equally into three groups, that is, the uncoated brackets and nanohydroxyapatite (nHA)-coated, and nanobioactive glass (nBG)-coated brackets using a spin coater machine. The brackets were bonded on the enamel surface and underwent remineralization/demineralization cycles for days 1, 7, 14, and 30. At each time interval, the bond strength of the brackets was assessed using mechanical loading. An optical and scanning electron microscope (SEM) were used for surface evaluation, and the adhesive remanent index (ARI) values were obtained and quantified.

STATISTICAL ANALYSIS

 One-way analysis of variance using Tukey's test was used to compare the differences among the groups.

RESULTS

 A uniform distribution of nanoparticles occurred on the surfaces of brackets. The shear bond strength (SBS) showed no significant differences in any tested groups on days 1, 7, and 14. However, control and nBG showed a significant difference from nHA at day 30. On days 7, 14, and 30, the nHA group showed the highest SBS values among the groups. For ARI, most samples showed an adhesive nature of failure at the enamel-brackets interface. The images confirmed the presence of coated particles on brackets and remnants of adhesives after SBS.

CONCLUSION

 This study confirmed that the nHA- and nBG-coated brackets have a high potential for application in orthodontics regarding structural and mechanical properties.

Morphological study of remineralization of the eroded enamel lesions by tyrosine-rich amelogenin peptide

BACKGROUND

Tyrosine-rich amelogenin peptide (TRAP) is the main amelogenin digestion product in the developmental enamel matrix. It has been shown to promote remineralization of demineralized enamel in our previous study. However, direct evidence of the effect of TRAP on the morphology and nanostructure of crystal growth on an enamel surface has not been reported. This study aimed to examine the effect of TRAP on the morphology of calcium phosphate crystals grown on early enamel erosion using a pH-cycling model.

METHODS

Eroded lesions were produced in human premolars by 30-second immersion in 37% phosphoric acid. Forty-five samples of eroded human premolar enamel blocks were selected and randomly divided into 3 groups: deionized water (DDW, negative control); 100 µg/mL TRAP, and 2 ppm sodium fluoride (NaF, positive control group). For 14 days, the specimens were exposed to a pH-cycling model. Using scanning electron microscopy (SEM) and atomic force microscopy (AFM) methods, the surface morphology, calcium-phosphorus ratio, and enamel surface roughness were examined. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) were used to assess crystal characteristics.

RESULTS

After pH-cycling, compared to the two control groups, the surface of the eroded enamel of the peptide TRAP group shows a large number of new, densely arranged rod-like crystals, parallel to each other, regularly arranged, forming an ordered structure, with crystal morphology similar to that of natural enamel. The crystals are mostly hydroxyapatite (HA).

CONCLUSION

This study demonstrates that the peptide TRAP modulates the formation of hydroxyapatite in eroded enamel and that the newly formed crystals resemble natural enamel crystals and promote the remineralization of enamel, providing a promising biomaterial for remineralization treatment of enamel lesions.

A comparative evaluation of human enamel remineralization ability of biomimetic nacre against casein phosphopeptide-amorphous calcium phosphate: An in vitro study

Introduction

This study aimed to assess and compare the efficacy of Nacre and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on the remineralization of enamel using surface microhardness analysis, scanning electron microscopy (SEM), and energy dispersive X-ray (EDX) spectroscopy.

Materials and Methods

Twenty human maxillary premolars extracted for orthodontic reasons were collected. Under cool water spray, the crowns were sectioned mesiodistally into buccal and palatal halves using a diamond disc. The samples were subsequently mounted in self-cure acrylic resin. The samples were then subjected to Vickers hardness testing and SEM-EDX for baseline. To simulate carious lesions, all of the samples were acid-etched with 37% phosphoric acid for 30 s in a specific area on the enamel samples and subjected to surface microhardness testing and SEM-EDX. The enamel samples were randomly assigned to Group 1: Nacre water-soluble matrix (WSM), Group 2: Nacre varnish, and Group 3: CPP-ACP for remineralization. After 21 days, remineralization assessment of the test samples was done using SMH analysis and SEM-EDX analysis. Data obtained were statistically analyzed using the one-way analysis of variance to reveal the significant differences between the groups. Tukey's test was used for post hoc comparisons.

Results

All three groups showed a significant increase in surface microhardness. All three groups showed a significant calcium and phosphorous ratio increase after remineralization. Among the three groups, the highest Ca:P ratio was seen in the Nacre WSM group (0.58) followed by the Nacre Varnish (0.57) and CPP-ACP group (0.57). SEM images of the Nacre surface revealed the presence of extensive interlocking. A layer of packed hydroxyapatite particles was formed on the surface of the nacre through surface reactions.

Conclusion

All the groups in the present study showed some extent of remineralizing ability irrespective of the different materials and mechanisms of action. Nacre WSM showed a remarkable hardness spike close to natural enamel after demineralization.

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

OBJECTIVES

The purpose of this study is to evaluate the remineralization potential of primary teeth enamel after being exposed to different laser diode therapies.

METHODS

Ninety-six vestibular primary teeth enamel samples were divided into eight groups (n = 12) with varying treatments: control (G1), CPP-ACP-fluoride varnish (G2), diode lasers at 980 nm (G3), 808 nm (G4), 450 nm (G5), 980 nm + CPP-ACP-fluoride varnish (G6), 808 nm + CPP-ACP-fluoride varnish (G7), and 450 nm + CPP-ACP-fluoride varnish (G8). Each sample was assessed using a DIAGNOdent® (KaVo Dental, Biberach, Germany), at baseline, post-treatment, and post-pH cycle remineralization. SEM imaging was performed before and after treatment and following the pH cycle.

RESULTS

The results indicated that the 980 nm and 808 nm diode lasers, both alone and in combination with CPP-ACP-fluoride varnish, either maintained or increased the calcium (Ca) weight percentage (Wt%) in the enamel. The 980 nm diode laser combined with CPP-ACP-fluoride varnish (G6) showed a significant increase in Ca Wt%, suggesting a strong remineralization effect. Similarly, the 808 nm diode laser alone (G4) also promoted a substantial increase in Ca Wt%. In contrast, the 450 nm diode laser, whether applied alone or in combination with CPP-ACP-fluoride varnish, resulted in a lower Ca Wt% and an increase in phosphorus (P) Wt%. Most groups, except for the CPP-ACP-fluoride varnish alone (G2), demonstrated an increase in P Wt%, indicating a complex interaction between laser therapy and enamel remineralization.

CONCLUSIONS

The combined use of laser therapy with CPP-ACP-fluoride varnish significantly enhanced the remineralization of temporary teeth enamel. The 980 nm diode laser + CPP-ACP-fluoride varnish showed the most pronounced improvement in remineralization, while the 808 nm diode laser alone also effectively increased calcium solubility. These findings suggest that higher-wavelength diode lasers, particularly when combined with remineralizing agents, can effectively enhance the mineral content of primary teeth and promote enamel remineralization.

The Effect of Formulated Dentin Remineralizing Gel Containing Hydroxyapatite, Fluoride, and Bioactive Glass on Dentin Microhardness: An In Vitro Study

Objectives

This study aimed to develop a gel with dentin-remineralizing properties, integrating nano-hydroxyapatite (nHA), sodium fluoride (NaF), and bioactive glass (BG).

Materials and Methods

The enamel layer of 40 bovine incisors was removed. The samples were allocated into four groups of 10 each, based on varying concentrations of nHA, BG, and NaF in the gel compositions (wt%): (1) 2.5%-7.5%-0.05%, (2) 5%-5%-0.05%, (3) 7.5%-2.5%-0.05%, and (4) a control group with a base gel lacking remineralizing agents. After 8 hr of demineralization, the dentin surface microhardness was measured at depths of 30, 60, and 140 µm. After a 20-day pH cycling, the percentage of surface microhardness recovery (SMHR%) was measured and compared among the groups using the ANOVA and Tukey HSD post hoc tests (α = 0.05). Scanning electron microscopy analysis evaluated each specimen's superficial morphology.

Results

At all depths, the SMHR% of the Group 2 and Group 3 was significantly higher than the control group (p  < 0.05). The SMHR% Group 1 (67.39% ± 29.34%) was significantly higher than the control group (-21.24% ± 51.72%) only at the depth of 30 μm (p = 0.047). Group 3 had higher SMHR% than Group 2 at all depths; however, the difference was not statistically significant. Moreover, the SMHR% of Group 3 was significantly higher than that of Group 1 at depths of 30 μm (187. 94% ± 68.95% vs. 67.39% ± 29.34%; p = 0.005) and 60 μm (179.55% ± 75.96% vs. 64.34% ± 41.96%; p = 0.043). Surface deposition and tubule occlusion were observed in the Groups 2 and 3 samples, which was more prominent in the latter.

Conclusions

Combining 7.5% nHA, 2.5% BG, and 0.05% NaF could potentially remineralize primary carious lesions.

The damage and remineralization strategies of dental hard tissues following radiotherapy

OBJECTIVES

This study pursued two main purposes. The first aim was to expound on the microscopic factors of radiation-related caries (RRC). Further, it aimed to compare the remineralization effect of different remineralizing agents on demineralized teeth after radiotherapy.

METHODS

The enamel and dentin samples of bovine teeth were irradiated with different doses of radiation. After analysis of scanning electron microscope (SEM), X-Ray diffraction (XRD), and energy dispersive spectrometer (EDS), the samples irradiated with 50 Gy radiation were selected and divided into the demineralization group, the double distilled water (DDW) group, the Sodium fluoride (NaF) group, the Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) group, the NaF + CPP-ACP group, and the Titanium tetrafluoride (TiF4) group. After demineralization, remineralizing agents treatment, and remineralization, the samples were evaluated using SEM, atomic force microscope (AFM), EDS, and transverse microradiography (TMR).

RESULTS

A radiation dose of 30 Gy was sufficient to cause damage to the dentinal tubules, but 70 Gy radiation had little effect on the microstructure of enamel. Additionally, the NaF + CPP-ACP group and the TiF4 group significantly promoted deposit formation, decreased surface roughness, and reduced mineral loss and lesion depth of demineralized enamel and dentin samples after radiation.

CONCLUSIONS

Radiation causes more significant damage to dentin compared to enamel. NaF + CPP-ACP and TiF4 had a promising ability to promote remineralization of irradiated dental hard tissues.

ADVANCES IN KNOWLEDGE

This in vitro study contributes to determining a safer radiation dose range for teeth and identifying the most effective remineralization approach for RRC.

Tooth whitening: current status and prospects

As a safe, effective, economical, and convenient technique, tooth whitening is one of the most popular treatments for improving tooth discoloration. This review summarizes the theoretical and recent research developments in the classification and mechanisms of tooth discoloration, as well as the principles, agents, effects, and side effects of tooth whitening techniques. The aim is to provide a basis for the clinical treatment of tooth whitening techniques and to suggest possible new ideas for further research. The accepted mechanism of whitening is the redox reaction of oxides in the whitening reagent, and the whitening effect is remarkable. However, side effects such as tooth sensitivity and irritation of gum and other oral soft tissues can still occur. It is recommended that more monitoring be carried out in the clinic to monitor these side effects, and care should be taken to protect the soft tissues in the mouth during office whitening procedures. Furthermore, there is a need to develop new additives or natural whitening products to reduce the occurrence of side effects.

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

OBJECTIVE

Assessed the effect of dental products containing nano-hydroxyapatite (nano-HA) + fluoride on the remineralization of white spot lesions (WSL) in vivo or in situ.

METHODS

Seven databases were explored using a two-pronged approach (intervention/treatment). After screening, full-text assessment, and further exclusion, the qualitative synthesis of five studies (four clinical and one in situ) was performed. Based on the Cochrane collaboration guidelines relevant data of the studies were collected and summarized. The Cochrane risk of bias tool for randomized trials (RoB 2.0) was used to appraise the studies' methodological quality and the GRADE guidelines to assess their level of evidence. The RoB 2.0 domains were rated on their risk of bias (RoB) as low, high, or with some concerns, and an adaptation of the tool was used to the in situ study.

RESULTS

The included studies assessed 151 WSL in anterior permanent teeth, on patients with varying ages. The protocol application, treatment length (7d-12 w), and control groups varied greatly between the studies making the performance of a quantitative analysis unfeasible. The general RoB of the clinical studies was classified as being of low risk (n = 2) or some concerns (n = 2). The in situ study was considered as being of low risk. The level of the evidence was moderate. Most of the studies found moderate evidence regarding the superiority of this association in clinical settings.

CONCLUSION

Even with the nano-HA + fluoride promising results for the remineralization treatment of WSL, due to the restricted number of studies and types of products, its extended use cannot be recommended based on the current systematic review, especially when considering the moderate level of the evidence found.

CLINICAL SIGNIFICANCE

Due to the biocompatibility and higher surface coverage of nano-HA and the remineralization capacity of fluoride formulations, the association of these elements to remineralize WSL has been positively reported. After the collection and qualitative appraise of the data, the clinical evidence of the use of these dental products is promising but limited.

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

AIM

Fluoride-Amorphous Calcium Phosphate and Biomimetic Nano-Hydroxyapatite for Enamel Remineralization; An In-Vitro Study of Surface Microhardness and Composition.

MATERIAL AND METHODS

Ninety-six extracted human premolars with sound buccal surface were divided using a randomization computer-generating software into four groups; Group I (control) sound untreated enamel, Group II (demineralized) demineralized to create white spot lesions, Group III (biom-n-HA) demineralized and then treated with biomimetic nanohydroxyapatite cream, and Group IV (F-ACP) demineralized and then treated using Fluoride-Amorphous Calcium Phosphate varnish. Each group was divided into two subgroups; subgroup "A" evaluated for mineral content using energy dispersive x-ray spectroscopy (EDX) and for surface microhardness using the Vickers microhardness test and Subgroup "B" evaluated for white spot lesion depth using a polarized light microscope (PLM).

RESULTS

The highest microhardness (VHN) was found in the (F-ACP) group (mean=428.61±54.43) and then in the (Biom-n-HA) group (mean=408.11±70.16) followed by the (Control) group (mean=402.13±53.40) with no significant difference between them and finally in the significantly different (Demineralized) group (mean=256.99±45.83). The weight percentage of Ca (30.29±1.04 and 33.44±1.07) and Ca/P ratio (1.87±0.06 and 2.03±0.05) were significantly different between Group III and Group IV respectively. PLM measurements in Group II (198.83μm), Group III (60.17μm), and Group IV (26.33μm) were significantly different.

CONCLUSIONS

Both the (Biom-n-HA) cream and the (F-ACP) varnish showed promising results for enamel remineralization. The increased enamel surface microhardness was consistent with the mineral content and the changes in the birefringence.

Biomimetic Remineralization of Artificial Caries Lesions with a Calcium Coacervate, Its Components and Self-Assembling Peptide P11-4 In Vitro

The application of calcium coacervates (CCs) may hold promise for dental hard tissue remineralization. The aim of this study was to evaluate the effect of the infiltration of artificial enamel lesions with a CC and its single components including polyacrylic acid (PAA) compared to that of the self-assembling peptide P11-4 in a pH-cycling (pHC) model. Enamel specimens were prepared from bovine incisors, partly varnished, and stored in demineralizing solution (DS; pH 4.95; 17 d) to create two enamel lesions per sample. The specimens were randomly allocated to six groups (n = 15). While one lesion per specimen served as the no-treatment control (NTC), another lesion (treatment, T) was etched (H3PO4, 5 s), air-dried and subsequently infiltrated for 10 min with either a CC (10 mg/mL PAA, 50 mM CaCl2 (Ca) and 1 M K2HPO4 (PO4)) (groups CC and CC + DS) or its components PAA, Ca or PO4. As a commercial control, the self-assembling peptide P11-4 (CurodontTM Repair, Credentis, Switzerland) was tested. The specimens were cut perpendicularly to the lesions, with half serving as the baseline (BL) while the other half was exposed to either a demineralization solution for 20 d (pH 4.95; group CC + DS) or pHC for 28 d (pH 4.95, 3 h; pH 7, 21 h; all five of the other groups). The difference in integrated mineral loss between the lesions at BL and after the DS or pHC, respectively, was analyzed using transversal microradiography (ΔΔZ = ΔZpHC - ΔZbaseline). Compared to the NTC, the mineral gain in the T group was significantly higher in the CC + DS, CC and PAA (p < 0.05, Wilcoxon). In all of the other groups, no significant differences between treated and untreated lesions were detected (p > 0.05). Infiltration with the CC and PAA resulted in a consistent mineral gain throughout the lesion body. The CC as well as its component PAA alone promoted the remineralization of artificial caries lesions in the tested pHC model. Infiltration with PAA further resulted in mineral gain in deeper areas of the lesion body.

Efficacy of Self-assembling Peptide P11-4 in Remineralizing In Vitro Caries-like Lesions in Primary Enamel Samples in Combination with Calcium Phosphate-based Remineralization Agents

Aims and background

The efficacy of self-assembling peptide P11-4 in combination with calcium-phosphate-based remineralization agents in remineralizing caries-like lesions in primary enamel was evaluated using a 21-day pH cycling experiment by Vickers microhardness [Vickers hardness number (VHN)] and scanning electron microscopy (SEM).

Materials and methods

A total of 120 primary enamel samples were made to undergo a demineralization cycle to produce caries-like lesions. They were divided into six groups, namely negative control (NC), positive control (P11-4), and four interventional groups in which each of the following calcium-phosphate-based agents were used in combination with P11-4-calcium sucrose phosphate (CSP), bioactive glass (BG), casein phosphopeptides, and casein phosphopeptides with fluoride. A 21-day pH cycling experiment was carried out with alternating demineralization and remineralization phases. The enamel samples were analyzed at baseline, post production of caries-like lesions, and post 21-day pH cycling using Vickers microhardness and SEM. Results were statistically analyzed using repeated measures of analysis of variance (ANOVA), keeping the level of significance at 0.05.

Results

Supplementing P11-4 with calcium-phosphate-based agents improved the surface hardness of the demineralized primary enamel samples, among which the fluoridated milk protein-based remineralization agent yielded a statistically significant improvement.

Conclusion

P11-4 promoted the regeneration of incipient caries-like lesions. However, there is added benefit when this peptide is used in combination with a fluoridated calcium-phosphate-based agent.

Clinical significance

This study would help the clinician compose an effective regimen for the patient to follow at home posttreatment with P11-4, in-office treatment.

How to cite this article

Krishnamoorthi A, Shanbhog RS, Godhi BS, et al. Efficacy of Self-assembling Peptide P11-4 in Remineralizing In Vitro Caries-like Lesions in Primary Enamel Samples in Combination with Calcium Phosphate-based Remineralization Agents. Int J Clin Pediatr Dent 2024;17(5):552-557.

Enamel Matrix Derivative, 58S5 Bioactive Glass, and Fluoride Varnish for Enamel Remineralization: A Multi-analysis Approach

PURPOSE

This study aimed to evaluate the enamel remineralization efficacy of enamel matrix derivative (EMD), experimental bioactive glass (BAG), and fluoride varnish in vitro.

METHODS AND MATERIALS

Artificial initial caries lesions were developed on fifty human enamel specimens using demineralization solution (pH 4.5, 37°C, 96 hours). Specimens were randomly assigned to five groups (n=10): I-5% NaF varnish (Enamelast), II-experimental 58S5 BAG+37% phosphoric acid (PA), III-EMD (Emdogain) + Ethylenediaminetetraacetic Acid (EDTA), IV-EMD+37% PA, V-Control (untreated). All remineralization agents were applied with pH cycling for seven days. The specimens were scanned by spectral domain optical coherence tomography (SD-OCT) at baseline, at demineralization, and after pH cycling. Lesion depths were measured using image analysis software (ImageJ). Lesions were evaluated using surface microhardness (SMH) and two fluorescence methods (FluoreCam and DIAGNOdent Pen [DDPen]). The data were statistically analyzed by Kruskal Wallis, Friedman, and Wilcoxon tests (α=0.05).

RESULTS

According to SD-OCT results, fluoride varnish was found to be the most effective agent in reducing lesion depth (p=0.005). All agents increased the SMH values after pH cycling. No significant difference was found among fluoride varnish, BAG, and EMD+PA groups. These SMH values were significantly higher than EMD+EDTA and control groups (p<0.001). All groups showed lower DDPen scores compared with the control group (p<0.001), however, no significant difference was found among the remineralization agents. In FluoreCam assessment, size and intensity values of all treated groups showed improvement. However, there was no significant difference between the treatment groups in terms of FluoreCam size measurements (p=0.186).

CONCLUSION

58S5 BAG and EMD+PA have remineralization capacity as effective as fluoride varnish. EMD+PA showed better SMH and lesion intensity results than EMD+EDTA.

The Assessment of Resin-Based Composite Sealants' Effectiveness in Arresting Non-Cavitated Dentin Carious Lesions (ICDAS 3)-A 12 Month Follow-Up Preliminary Study

Background and Objectives: The therapeutic management of carious lesions remains a significant focus for researchers, given their persistently high prevalence despite being largely preventable. This study aimed to compare the effectiveness of a composite resin-based sealant material in halting extended non-cavitated dentin carious lesions when used therapeutically versus preventively on caries-free teeth over a period of twelve months. Materials and Methods: out of the 236 children examined, 45 were excluded from the study due to non-compliance with the inclusion criteria. Thus, the study included 191 children aged 10-12 years, and 764 molars in total. Results: among these molars, 171 were caries-free (ICDAS II code 0), forming the Control group, while 180 molars were classified with an ICDAS II score of 3, forming the Study group. All molars were sealed and evaluated at 6- and 12-month follow-up intervals. Both intervals revealed statistically significant differences (p < 0.05) in sealant retention and carious lesion development between sound (ICDAS code 0) and decayed (ICDAS code 3) teeth. Conclusions: the findings did not support the effectiveness of sealants in halting non-cavitated dentin carious lesions classified as ICDAS II with code 3 compared to their preventive application in sound teeth classified as ICDAS II with code 0.

Parental concerns about oral health of children: Is ChatGPT helpful in finding appropriate answers?

INTRODUCTION

Artificial intelligence (AI) is becoming an important part of our lives owing to increased data availability and improved power of computing. One of the recently launched modalities of AI, ChatGPT, is being enormously used worldwide for different types of tasks. In medical context, its use is being explored for clinical queries, academia, research help, etc. Further, literature suggests that parents seek information about health of their children using different Internet resources and would surely turn toward ChatGPT for the same, as this chatbot model is easy to use, generates "one" response, and is available without any subscription. ChatGPT generates a response using text cues and applying different algorithms on prepublished literature but is still in its naïve state; hence, it is imperative to validate the generated responses. Accordingly, we planned this study to determine the clarity, correctness, and completeness of some Frequently asked questions (FAQs) about child's oral health, from a mother's perspective.

METHODS

The study design was a vignette-based survey and included a set of 23 questions, for which ChatGPT was interviewed from the perspective of an imaginary parent. The answers responded by ChatGPT were copied "verbatim," and a Google survey form was designed. The survey form was validated and then sent to 15 pediatric dentists, and the responses were mainly collected on the Likert's scale with a provision of one open-ended question aiming to determine "what they would have added" to this generated response as an expert in the field.

RESULTS

The responses on Likert's scale were condensed and values ≥4 were considered 'adequate and acceptable' while scores ≤3, were considered 'inadequate'. The generated responses and comments mentioned by different respondents in the open-ended question were critiqued in reference to the existing literature.

CONCLUSION

Overall, the responses were found to be complete and logical and in clear language, with only some inadequacies being reported in few of the answers.

Comparative Evaluation of Remineralizing Potential of Topical Cream Containing Casein Phosphopeptide-Amorphous Calcium Phosphate and Casein Phosphopeptide-Amorphous Calcium Phosphate with Fluoride: An In Vitro Study

The requirement for clinically effective treatments to remineralize early enamel caries lesions is dictated by the principles of minimally invasive dentistry. Numerous studies outlined the significance of treating early carious lesions with different remineralizing agents. This study aimed to evaluate and compare the remineralization potential of topical cream containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and CPP-ACP with fluoride in remineralizing artificial carious lesions on enamel. Forty-five freshly extracted human premolar teeth were selected as samples. These samples were divided into three groups: Group I-regular toothpaste without specific remineralizing agent; Group II-topical cream containing CPP-ACP and Group III topical cream containing CPP-ACP with fluoride. All the samples were viewed under scanning electron microscope (SEM) to assess the topographical pictures of the enamel surface and also subjected to energy dispersing X-ray analysis (EDX) for quantitative estimation of minerals, calcium (Ca), and phosphorous (P). In the result of the study, Group I does not show any increase in the Ca and P after applying toothpaste without any remineralizing agent but Group II and Group III showed a net increase in Ca and P- values after applying concerned remineralizing agents. Intergroup comparison showed Group III yielded higher net Ca and P- values than Group II. Two remineralizing agents showed remineralization potential on samples. Descriptive statistics were used to calculate the mean and standard deviation. Mann-Whitney test was used. The level of significance was set at 0.05. CPP-ACP containing fluoride showed better remineralizing potential than CPP-ACP. Hence, CPP-ACP containing fluoride can be considered the material of choice in remineralizing early enamel carious lesions.

New generation of orthodontic devices and materials with bioactive capacities to improve enamel demineralization

OBJECTIVE

The article reviewed novel orthodontic devices and materials with bioactive capacities in recent years and elaborated on their properties, aiming to provide guidance and reference for future scientific research and clinical applications.

DATA, SOURCES AND STUDY SELECTION

Researches on remineralization, protein repellent, antimicrobial activity and multifunctional novel bioactive orthodontic devices and materials were included. The search of articles was carried out in Web of Science, PubMed, Medline and Scopus.

CONCLUSIONS

The new generation of orthodontic devices and materials with bioactive capacities has broad application prospects. However, most of the current studies are limited to in vitro studies and cannot explore the true effects of various bioactive devices and materials applied in oral environments. More research, especially in vivo researches, is needed to assist in clinical application.

CLINICAL SIGNIFICANCE

Enamel demineralization (ED) is a common complication in orthodontic treatments. Prolonged ED can lead to dental caries, impacting both the aesthetics and health of teeth. It is of great significance to develop antibacterial orthodontic devices and materials that can inhibit bacterial accumulation and prevent ED. However, materials with only preventive effect may fall short of addressing actual needs. Hence, the development of novel bioactive orthodontic materials with remineralizing abilities is imperative. The article reviewed the recent advancements in bioactive orthodontic devices and materials, offering guidance and serving as a reference for future scientific research and clinical applications.

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.

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

BACKGROUND

Several methods were introduced for enamel biomimetic remineralization that utilize a biomimetic analogue to interact and absorb bioavailable calcium and phosphate ions and induce crystal nucleation on demineralized enamel. Amelogenin is the most predominant enamel matrix protein that is involved in enamel biomineralization. It plays a major role in developing the enamel's hierarchical microstructure. Therefore, this study was conducted to evaluate the ability of an amelogenin-inspired peptide to promote the remineralization potential of fluoride and a supersaturated calcium phosphate solution in treating artificially induced enamel carious lesions under pH-cycling regimen.

METHODS

Fifty enamel slices were prepared with a window (4*4 mm2 ) on the surface. Five samples were set as control healthy enamel and 45 samples were subjected to demineralization for 3 days. Another 5 samples were set as control demineralized enamel and 40 enamel samples were assigned into 8 experimental groups (n=5) (P/I, P/II, P/III, P/AS, NP/I, NP/II, NP/III and NP/AS) according to peptide treatment (peptide P or non-peptide NP) and remineralizing solution used (I; calcium phosphate solution, II; calcium phosphate fluoride solution, III; fluoride solution and AS; artificial saliva). Samples were then subjected to demineralization/remineralization cycles for 9 days. Samples in all experimental groups were evaluated using Raman spectroscopy for mineral content recovery percentage, microhardness and nanoindentation as healthy, demineralized enamel and after pH-cycling. Data were statistically analysed using two-way repeated measures Anova followed by Bonferroni-corrected post hoc test for pairwise multiple comparisons between groups. Statistical significance was set at p= 0.05. Additionally, XRD, FESEM and EDXS were used for crystal orientation, surface morphology and elemental analysis after pH-cycling.

RESULTS

Nanocrystals clumped in a directional manner were detected in peptide-treated groups. P/II showed the highest significant mean values in mineral content recovery (63.31%), microhardness (268.81±6.52 VHN), elastic modulus (88.74±2.71 GPa), nanohardness (3.08±0.59 GPa) and the best crystal orientation with I002/I300 (1.87±0.08).

CONCLUSION

Despite pH changes, the tested peptide was capable of remineralizing enamel with ordered crystals. Moreover, the supplementary use of calcium phosphate fluoride solution with peptide granted an enhancement in enamel mechanical properties after remineralization.

Pomegranate extract in polyphosphate-fluoride mouthwash reduces enamel demineralization

OBJECTIVES

To evaluate the anti-demineralizing effect of a mouthwash comprising pomegranate peel extract (PPE 3%), sodium trimetaphosphate (TMP 0.3%), and fluoride (F 225 ppm) in an in situ study, and to assess its irritation potential in an ex vivo study.

METHODS

This double-blind crossover study was conducted in four phases with 7 days each. Twelve volunteers used palatal appliances containing enamel blocks, which were subjected to cariogenic challenges. The ETF formulation (PPE + TMP + F, pH 7.0), TF formulation (TMP + F, pH 7.0), deionized water (W, pH 7.0), and essential oil commercial mouthwash (CM, 220 ppm F, pH 4.3) were dropped onto the enamel twice daily. The percentage of surface hardness loss, integrated loss of subsurface hardness, calcium, phosphorus, and fluoride in enamel and biofilms were determined. In addition, alkali-soluble extracellular polysaccharide concentrations were analyzed in the biofilms. The irritation potential was evaluated using the hen's egg chorioallantoic membrane test through the vascular effect produced during 300-s of exposure.

RESULTS

ETF was the most efficacious in preventing demineralization. It also showed the highest concentrations of calcium and phosphorus in the enamel and in the biofilm, as well as the lowest amount of extracellular polysaccharides in the biofilm. In the eggs, ETF produced light reddening, whereas CM led to hyperemia and hemorrhage.

CONCLUSIONS

The addition of PPE to formulations containing TMP and F increased its anti-demineralizing property, and this formulation presented a lower irritation potential than the CM.

CLINICAL RELEVANCE

ETF can be a promising alternative alcohol-free mouthwash in patients at high risk of caries.

The Influence of Fluoride Gels on the Physicochemical Properties of Tooth Tissues and Dental Materials-A Systematic Review

The aim of the presented systematic review is to update the state of knowledge and relate the properties and composition of fluoride gels to their potential application. This article aims to explore the effect of fluoride gel application on changes in the properties of dental biomaterials and tooth tissues. The review includes articles assessing studies on the effects of fluoride gel on dental tissues and materials. Employing the PRISMA protocol, a meticulous search was conducted across the PubMed, Scopus, and Web of Science databases, utilizing keywords such as fluoride, gel, and properties. The publications were selected without limitation by the year of publication, and then Cohen's κ test was used to assess the agreement of the respondents. Exclusion criteria included non-English studies, opinion pieces, editorial papers, letters to the editor, review articles and meta-analyses, clinical reports, studies lacking full-text accessibility, and duplicates. The quality of the chosen papers was assessed by two independent reviewers. A total of 2385 were located in databases, of which only 17 met the inclusion criteria. All publications showed increased surface mineralization, and seven studies showed the effect of fluoride gel on the surface of dental tissues. Three articles stated a negative effect of fluoride gels on titanium and stainless steel alloys and glass ionomer fillings. The effects on shear bond strength and plaque deposition require further investigation because the study results are contradictory.

Antibiofilm Properties and Demineralization Suppression in Early Enamel Lesions Using Dental Coating Materials

This study aimed to investigate the effects of dental coating materials on Streptococcus mutans biofilm formation. The test materials were PRG Barrier Coat (PRG), BioCoat Ca (BioC), and FluorDental Jelly (FluorJ). Bovine enamel specimens were demineralized to mimic early enamel lesions. The biofilm was developed on a specimen treated with one of the materials by using a modified Robbins device flow-cell system. Scanning electron and fluorescence confocal laser scanning microscopy, viable and total cell counts, and gene expression assessments of the antibiofilm were performed. Ion incorporation was analyzed using a wavelength-dispersive X-ray spectroscopy electron probe microanalyzer. All materials allowed biofilm formation but reduced its volume. FluorJ was the only material that inhibited biofilm accumulation and had a bactericidal effect, revealing 0.66 log CFU in viable cells and 1.23 log copy reduction in total cells compared with the untreated group after 24 h of incubation. The ions released from PRG varied depending on the element. BioC contributed to enamel remineralization by supplying calcium ions while blocking the acid produced from the biofilm. In summary, the dental coating materials physically prevented acid attacks from the biofilm while providing ions to the enamel to improve its mechanical properties.

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.

Effectiveness of plant-mediated synthesis of hydroxyapatite nano-particles impregnated in Pistachio oleogum resin on mineral contents of human teeth. An in-situ single-blind controlled study

OBJECTIVES

This study aimed to synthesize and characterize an environmentally friendly nanohydroxyapatite (n-HA) and evaluate its impact on enamel mineral content when incorporated into a Pistachio oleo gum resin (Saqqez) bio-chewing gum for in-situ models. We compared the effects of this green nano-hydroxyapatite (G n-HA) with those of a commercially available synthetic nano-hydroxyapatite (S n-HA).

METHODS

Various analytical techniques were employed including XRD, FESEM, FT-IR, EDX/SEM and TGA/DTA to characterize the crystallinity, size and composition of the G n-HA powder. Three chewing gum groups were formulated: (1) Saqqez gum containing 10% wt G n-HA, (2) Saqqez gum containing 10% wt S n-HA, and (3) pure Saqqez gum. In order to evaluate the impact of these chewing gums on enamel, intraoral appliances were fabricated, each containing six enamel specimens. Participants were instructed to chew the gums while wearing these appliances. The calcium (Ca+2) and phosphorus (P) levels in enamel specimens, both with and without exposure to an acid challenge, were quantified using EDX/SEM. FE-SEM was employed to capture the microstructure of the enamel surface. In terms of the statistical analysis, one-way ANOVA and Tukey's post hoc tests were utilized to compare the data, where the significance level (α) was set at 0.05.

RESULTS

The characterization tests confirmed the successful synthesis of G n-HA. Furthermore, EDX/SEM analysis of the enamel specimens from the intraoral appliance revealed significant variations in calcium (Ca+2) content among the enamel specimens (P = 0.000). The S n-HA group, in particular, exhibited the highest Ca+2 content, while the pure Saqqez group displayed the lowest. Nonetheless, there was no statistically significant differences in phosphorus (P) content observed among the three groups (P = 0.27).

CONCLUSIONS

Saqqez gum can be considered a wholesome natural chewing gum that serves, as a carrier for delivering remineralization agents to the tooth surfaces. This was evident in the groups containing n-HA, exhibiting elevated Ca+2 levels. It's noteworthy that G n-HA demonstrated less efficacy in enamel remineralization compared to S n-HA.

Advances in Preventive and Therapeutic Approaches for Dental Erosion: A Systematic Review

This review discusses both preventive measures and clinically implemented therapy procedures that have been developed recently for the prevention and treatment of tooth erosion.

METHODS

The databases PubMed, Scopus, and Web of Science were used for a thorough search. Studies on the prevention and treatment of dental erosion that were conducted in English and used in vitro were among the inclusion criteria.

RESULTS

The search turned up 391 papers in total, with 34 of those publications matching the requirements for inclusion. Varnishes, toothpastes, and solutions containing fluoride and other substances were used as preventive measures.

CONCLUSIONS

Dental erosion is a significant issue, and taking preventative steps is crucial to lessening the disease's spread and its effects. Interventions based on fluoride seem to be successful at halting erosion and encouraging remineralization. To effectively address severe tooth erosion, therapeutic methods, including composite restorations, prosthetic crowns, and veneers, are available. Dental erosion causes aesthetic and functional issues that are best addressed with less invasive treatments like direct composite restorations. To improve and broaden the range of available treatments for this common dental issue, additional research and development are required.

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.

A Remineralizing and Antibacterial Coating for Arresting Caries

Dental caries is a dynamic disease induced by the unbalance between demineralization of dental hard tissues caused by biofilm and remineralization of them; however, although various effective remineralization methods have been well documented, it is a challenge to reestablish the balance by enhancing remineralization alone while ignoring the antibacterial therapy. Therefore, the integration of remineralizing and antibacterial technologies offers a promising strategy to halt natural caries progression in clinical practice. Here, the conception of interrupting dental caries (IDC) was proposed based on the development of dual-functional coating with remineralizing and antibacterial properties. In this study, bovine serum albumin (BSA) loaded octenidine (OCT) successfully to form a BSA-OCT composite. Subsequently, through fast amyloid-like aggregation, the phase-transited BSA-OCT (PTB-OCT) coating can be covered on teeth, resin composite, or sealant surfaces in 30 min by a simple smearing process. The PTB-OCT coating showed satisfactory effects in promoting the remineralization of demineralized enamel and dentin in vitro. Moreover, this coating also exerted significant acid-resistance stability and anti-biofilm properties. Equally importantly, this coating exhibited promising abilities in reducing the microleakage between the tooth and resin composite in vitro and preventing primary and secondary caries in vivo. In conclusion, this novel dual-functional PTB-OCT coating could reestablish the balance between demineralization and remineralization in the process of caries, thereby potentially preventing or arresting caries.

Fluoride Release and Rechargeability of Poly(lactic acid) Composites with Glass Ionomer Cement

This study investigates the fluoride release, rechargeability and degradation behaviors of newly developed anticariogenic poly(lactic acid) (PLA) composites. The PLA composite with various concentrations (0%, 5%, 10%, 15% and 20% by weight) of glass ionomer cement (GIC) and sodium fluoride (NaF) were prepared using solvent casting method. The fluoride release, fluoride rechargeability and degradation behavior were evaluated. All experimental groups demonstrated fluoride-releasing ability. The highest level of fluoride ions released was found in PLA composite with sodium fluoride (PLA/NaF). Following the 28-day period, both groups showed a gradual reduction in fluoride ion released, ranging between 0.03 ± 0.01 and 0.53 ± 0.06 ppm, although remaining within the effective range for tooth remineralization. However, the rechargeability was only observed in PLA composite with GIC (PLA/GIC). Following an eight-week in vitro degradation test, all PLA/NaF groups displayed a significantly higher percentage of weight change and water absorption compared to the PLA/GIC and the control group. In SEM analysis, the formation of surface porosities was clearly noticed in all PLA/NaF. All specimens retained their structural integrity throughout the study. In conclusion, the newly developed PLA/GIC displays promising possibilities as an anticariogenic material. Furthermore, the rechargeability of these ions are repeatable, ensuring their long-term utility.

Remineralising potential of Ocimum basilicum varnish and fluoride varnish on initial enamel caries: An in vitro microscopic study

Background

The focus of caries research has switched to early identification and non-invasive treatment of carious lesions.

Aim

This study aimed to evaluate and compare the remineralising potential of Ocimum (O.) basilicum varnish and fluoride varnish on initial enamel caries.

Method

The authenticated O. basilicum seeds were procured from a repository, and the extract was prepared using the Soxhlet method, which was vortexed with Indian Pharmaceutical (IP)-graded chemicals to obtain varnish. Extracted premolar tooth samples were divided into three groups of 33 each after demineralisation with a pH of 4.5 for 48 hours at 37°C. Each group was subjected to remineralisation twice daily with respective agents for 4 minutes for 30 consecutive days. Each sample was ground-sectioned through an enamel window. The lesion depth was measured using a light microscope (Leica™ DM2500) and ImageJ software. The data were evaluated using analysis of variance (ANOVA) and post hoc analysis.

Results

The mean (± SD) pre-treatment lesion depth across the groups ranged from 242.11 ± 26.144 μm to 352.66 ± 34.531 μm. The highest lesion depth recovery rate of 45.938% was recorded for the fluoride varnish group, followed by 36.015% in the O. basilicum varnish group, which was statistically significant by Tukey's post hoc analysis (p < 0.001). The gingival fibroblast cells were viable by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay.

Conclusion

The O. basilicum varnish demonstrated a homogenous layer of mineral deposition. However, the remineralising efficacy was slightly lesser than that of the fluoride varnish. Hence, the novel O. basilicum-based remineralisation agent appears to have potential as a non-invasive alternative to topical fluorides in the therapy of early caries lesions.

Brief Narrative Review on Commercial Dental Sealants-Comparison with Respect to Their Composition and Potential Modifications

The scope of this paper is to compare different dental sealants and flow materials indicated for sealing pits and fissures considering their chemical formula. The narrative review aims to address the following questions: What is the essence of different dental sealants' activity, how does their chemical formula affect their mechanisms of caries prevention, and what makes a dental sealant efficient mean of caries prevention? Another vital issue is whether the sealants that contain fluoride, or any other additions, have potentially increased antimicrobial properties. An electronic search of the PubMed, Cochrane, Web of Science, and Scopus databases was performed. The following keywords were used: (dental sealants) AND (chemical composition). Additionally, information about composition and indications for clinical use provided by manufacturers were utilized. All of the considered materials are indicated for use both in permanent and primary dentition for sealing fissures, pits, and foramina caeca. The selection of suitable material should be made individually and adjusted to conditions of the sealing procedure and patient's needs. Cariostatic mechanisms increasing sealants' effectiveness such as fluoride release are desired in modern dentistry appreciating preventive approach. The review aims are to find crucial elements of sealants' composition which affect their cariostatic mechanisms.

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.

Carboxymethyl Chitosan-Fluoride-doped Amorphous Calcium Phosphate: A Novel Remineralizing Gel

Background

There is a need for innovative remineralizing gel formulations based on calcium and phosphates that can slowly release fluoride ions and enhance the formation of fluorapatite crystals that are more resistant to dissolution in an acidic environment.

Aim

The aim of the work was to formulate a remineralizing agent that remineralizes enamel through the release of Ca2+, PO₄³-, and F- ions for a prolonged period of time.

Materials and methods

The gel was based on carboxymethyl chitosan (CMC) as a bioinspired gelling agent and on Fluoride-doped Amorphous Calcium Phosphate (F-ACP) as a remineralizing agent. This gel was tested in vitro on the enamel of extracted premolars after demineralization with methacrylic acid gel.

Results

When compared to the control group and demineralized enamel group, the enamel slabs remineralized with CMC/F-ACP showed a higher calcium phosphate ratio in Energy-Dispersive X-ray (EDX) and better surface morphology under scanning electron microscope (SEM).

Conclusion

Remineralization tests performed on demineralized human permanent teeth proved that CMC/F-ACP gel has excellent efficacy, inducing a complete remineralization of the outermost layers of enamel as well as a full restoration of lost mineral content.

How to cite this article

Nimbeni BS, Nimbeni SB, Divakar DD, et al. Carboxymethyl Chitosan-Fluoride-doped Amorphous Calcium Phosphate: A Novel Remineralizing Gel. Int J Clin Pediatr Dent 2023;16(5):734-739.

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.

An In-Vitro Comparative Study of Fluoride Varnish and Two Calcium-Containing Fluoride Products on the Remineralization of Primary Teeth Enamel

Objectives: To compare the effectiveness of fluoride varnish and two calcium-based fluoride products on the remineralization of primary teeth enamel. Materials and Methods: Surface-microhardness (SMH) of 36 extracted anterior primary teeth was measured by Vickers test (50gr/5 seconds) to provide a baseline for later comparisons. All teeth were immersed in demineralizing solution for 96 hours to create caries-like lesions and SMH was determined for the artificially-induced caries. The teeth were randomly assigned to three groups consisting of 5% fluoride varnish once daily/10 seconds, Clinpro™ 5000 toothpaste once daily/2 minutes, and Remin Pro cream once daily/3 minutes for 28 days. All specimens were kept in artificial saliva with pH cycling during the study period. After remineralization, SMH was evaluated for the last time. Data were analyzed by one-way ANOVA, Mauchly's sphericity, and RM-ANOVA with Bonferroni correction for inter-and- intra-group comparisons at the three stages of the study. Results: Neither the baseline SMH nor the SMH of the artificially created caries showed significant differences among the samples (P>0.05). The post-treatment SMH was highest in the Clinpro group (296.4±73.1kgf/mm2), followed by Remin Pro (283.8±119.3kgf/mm2), and varnish (270.9±78.3 kgf/mm2). There was no significant difference among the groups after treatment (P>0.05). We also did not observe a significant difference among the three different study stages (P>0.05). Conclusion: Within the limitations of this in-vitro study, daily application of low fluoride-calcium compound seems to be as effective as the professional use of fluoride varnish or high-content fluoride toothpaste in remineralizing initial caries of primary teeth.

Remineralization Effect of Calcium Glycerophosphate in Fluoride Mouth Rinse on Eroded Human Enamel: An In Vitro Study

Aims and Objectives

The aim of this in vitro study was to evaluate the remineralization effect of calcium glycerophosphate (CaGP) in fluoride mouth rinse on permanent enamel eroded by a soft drink.

Materials and Methods

Forty sound permanent premolars were embedded in self-curing acrylic resin and immersed in Coca-Cola to create erosive lesions. The teeth were divided into four groups (n = 10): Group I artificial saliva; Group II sodium fluoride; Group III sodium fluoride + sodium monofluorophosphate; and Group IV sodium monofluorophosphate + CaGP. The specimens in the assigned groups underwent pH cycling for ten days. The baseline, after erosion, and after remineralization surface microhardness (SMH) values were determined. The data were analyzed by one-way analysis of variance (ANOVA). The mean SMH value between groups and one-way repeated measures ANOVA for the mean SMH value within each group and Bonferroni's for multiple comparisons at a 95% confidence level were determined. The average SMH was used and calculated as the percentage recovery of SMH.

Results

After being eroded by the cola soft drink, the mean SMH values in all groups were significantly decreased. After remineralization, Group I had the lowest %SMHR. The %SMHR of Groups II, III, and IV were significantly higher than Group I (P < 0.001). However, there were no significant differences among Groups II, III, and IV (P > 0.05).

Conclusions

Fluoride mouth rinse with and without CaGP showed similar efficacies in remineralizing eroded permanent enamel.

Regenerative and Protective Effects on Dental Tissues of a Fluoride-Silicon-Rich Toothpaste Associated with a Calcium Booster: An In Vitro Study

Calcium boosters have been used as a supplement for fluoride toothpastes to repair the dental tissues and reduce dentin permeability. This in vitro study aimed to characterize the regenerative and protective effects of the treatment of dental tissues with a fluoride-silicon-rich toothpaste associated with a calcium booster. Bovine enamel and dentin blocks (n = 5) were obtained (4 × 4 × 6 mm). A fluoride-silicon-rich toothpaste and a calcium booster were used to brush the enamel and dentin both immediately and five days afterwards. The outcomes were then compared to those of the untreated control group. After that, the specimens were cross-sectioned. SEM was used to evaluate the micromorphology of the surface and cross-section. Energy-dispersive X-ray spectroscopy (EDS) was used to determine the elemental analyses (weight%). After treatment for 5 days with a booster/silicon-rich toothpaste, EDS analysis demonstrated that it induced a significant mineral change. It was also able to form a protective silicon-enriched mineral layer on both enamel and dentin surfaces. It was demonstrated in vitro that a fluoride-silicon-rich toothpaste associated with a calcium booster regenerates the dental tissues, remineralizing the enamel structure and occluding the dentin tubules.

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.

The revolutionary evolution in carious lesion management

Contemporary paradigms of dental caries management focus on the biological approaches to treating the disease and its principal symptom, the carious lesion. This narrative review traces the evolution of carious lesion management from the operative and invasive approaches of G. V. Black's era to the current period of minimally invasive biological approaches. The paper explains the rationale for adopting biological approaches to dental caries management and lists the five core principles of this management approach. The paper also details the aims, features, and the most recent evidence base for the different biological carious lesion management approaches. Based on current practice guidelines, collated clinical pathways for lesion management are also presented in the paper to aid clinicians in their decision-making. It is hoped that the biological rationale and evidence summarized in this paper will bolster the shift to modern biological carious lesion management approaches among dental practitioners.

Assessment of the Remineralizing Potential of Biomimetic Materials on Early Artificial Caries Lesions after 28 Days: An In Vitro Study

This study aimed to evaluate the loss of mineral content in the enamel surface in early artificial lesions and to assess the remineralizing potential of different agents by means of SEM coupled with energy-dispersive X-ray analysis (EDX). The analysis was performed on the enamel of 36 molars divided into six equal groups, in which the experimental ones (3-6) were treated using remineralizing agents for a 28-day pH cycling protocol as follows: Group 1, sound enamel; Group 2, artificially demineralized enamel; Group 3, CPP-ACP treatment; Group 4, Zn-hydroxyapatite treatment; Group 5, NaF 5% treatment; and Group 6, F-ACP treatment. Surface morphologies and alterations in Ca/P ratio were evaluated using SEM-EDX and data underwent statistical analysis (p < 0.05). Compared with the sound enamel of Group 1, the SEM images of Group 2 clearly showed loss of integrity, minerals, and interprismatic substances. Groups 3-6 showed a structural reorganization of enamel prisms, interestingly comprising almost the entire enamel surface. Group 2 revealed highly significant differences of Ca/P ratios compared with other groups, while Groups 3-6 showed no differences with Group 1. In conclusion, all tested materials demonstrated a biomimetic ability in remineralizing lesions after 28 days of treatment.

Synchrotron X-ray Studies of the Structural and Functional Hierarchies in Mineralised Human Dental Enamel: A State-of-the-Art Review

Hard dental tissues possess a complex hierarchical structure that is particularly evident in enamel, the most mineralised substance in the human body. Its complex and interlinked organisation at the Ångstrom (crystal lattice), nano-, micro-, and macro-scales is the result of evolutionary optimisation for mechanical and functional performance: hardness and stiffness, fracture toughness, thermal, and chemical resistance. Understanding the physical-chemical-structural relationships at each scale requires the application of appropriately sensitive and resolving probes. Synchrotron X-ray techniques offer the possibility to progress significantly beyond the capabilities of conventional laboratory instruments, i.e., X-ray diffractometers, and electron and atomic force microscopes. The last few decades have witnessed the accumulation of results obtained from X-ray scattering (diffraction), spectroscopy (including polarisation analysis), and imaging (including ptychography and tomography). The current article presents a multi-disciplinary review of nearly 40 years of discoveries and advancements, primarily pertaining to the study of enamel and its demineralisation (caries), but also linked to the investigations of other mineralised tissues such as dentine, bone, etc. The modelling approaches informed by these observations are also overviewed. The strategic aim of the present review was to identify and evaluate prospective avenues for analysing dental tissues and developing treatments and prophylaxis for improved dental health.

Organic volume and permeability variations in the surface layer of artificial and natural enamel carious lesions

OBJECTIVES

Test the hypothesis the type of enamel caries (natural, artificial induced by gel, and artificial induced by acid solutions) affect the organic volume and the permeability of the surface layer in enamel caries lesions.

DESIGN

Artificial enamel caries, induced by either acidic solution (organic-poor; Group 1) or acidic gel (organic-rich; Group 2), and natural non-cavitated inactive approximal enamel caries lesions (NEC; Group 3) were obtained, from which longitudinal ground sections were prepared. Measurements of the mineral (V_min) (by microradiography), and water (α) and organic (β) volumes (by optical birefringence) were obtained at three points in the surface layer (n = 30/group).

RESULTS

The main outcomes were the ratio between experimental β by predicted β (β Ratio) and the ratio between experimental and predicted permeabilities (α_d Ratio). β Ratio in Group 1 was lower than in Groups 2 (Cohen's d: -1.81; 95% CI:-1.45,-2.32; p < 0.001) and 3 (Cohen's d: -0.71; 95% CI:-0.27,-1.18; p = 0.004), and Group 2 surpassed Group 3 (Cohen's d: 0.49; 95% CI:0.07,0.94; p = 0.03). α_d Ratio in Group 1 was higher than in Groups 2 (Cohen's d: 1.86; 95% CI:1.49,2.33; p < 0.001) and 3 (Cohen's d: 0.60; 95% CI:0.18,1.14; p = 0.01), and Group 3 surpassed Group 2 (Cohen's d: 0.61; 95% CI:0.23,1.07; p = 0.01).

CONCLUSIONS

The highest organic volume and the lowest permeability occurred at the surface layer of gel-induced artificial enamel caries lesions, which should be preferred in in vitro studies on de- and remineralization and resin infiltration.

Regenerative biomineralization potential of commercially available remineralizing agents as a preventive treatment approach for tooth erosion - An in vitro laser-induced breakdown spectroscopy analysis

Context

In today's era, erosion is the most prevalent type of tooth wear. The prevention of demineralization with biomineralization is the most desired treatment.

Aim

The aim of this study is to evaluate and compare the surface remineralization potential of two remineralizing agents - self-assembling peptide P11-4 (SAP P11-4) and calcium silicate plus sodium phosphate (CSSP) salts on intact and demineralized enamel using laser-induced breakdown spectroscopy (LIBS).

Subjects and Methods

Sixteen maxillary premolars were decoronated and split into buccal and palatal halves embedded in acrylic resin with a total sample size of 32 designated into Group 1 (intact teeth) and Group 2 (demineralized teeth). Further subdivision into Groups 1a and 2a (SAP P11-4 group [n = 8]); Groups 1b and 2b (CSSP group [n = 8]), Group 2 was first exposed to Coca-Cola. Then, all groups were subjected to experimental LIBS. Groups 1a and 2a were treated with SAP P11-4 based product, i.e., CURODONT™ PROTECT gel. Groups 1b and 2b were treated with CSSP-based products regimen, i.e., REGENERATE Enamel Science™ Advanced Toothpaste and Advanced Enamel Serum. The LIBS assessment was redone for all groups to attain a change in Ca and P values.

Statistical Analysis Used

Inferential statistics were done using Wilcoxon signed-rank test (Before-After product application) and Mann-Whitney U-test (between the groups).

Results

According to the statistical evaluation there was a statistically significant difference (P < 0.05), in Ca and P values in demineralized teeth when both SAP P11-4 and CSSP groups were evaluated. Although Ca values exhibited a significant difference in intact teeth, P did not exhibit a significant difference on the application of both remineralizing agents. The remineralizing potential between the two agents, SAP P11-4 and CSSP groups. There was no statistically significant difference ( P <0.05) observed between the two agent's remineralization potential for intact and demineralized teeth.

Conclusion

SAP P11-4 and CSSP have the potential to remineralize both intact and demineralized enamel. There was increased remineralization in demineralized samples subjected to erosion.

The effect of Phytosphingosine and bioactive glass-ceramics in preventing dental enamel erosion

This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey's test; and Ra, by 2-way ANOVA, repeated measures, and Tukey's test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

Biomimetic Action of Zinc Hydroxyapatite on Remineralization of Enamel and Dentin: A Review

Biomimetic zinc-carbonate hydroxyapatite technology was developed to realize materials that mimic the natural hydroxyapatite of enamel and dentin and possess good activity in terms of affinity to adhere to these biological tissues. The chemical and physical characteristics of this active ingredient allows the hydroxyapatite itself to be particularly similar to dental hydroxyapatite, enhancing the bond between biomimetic hydroxyapatite and dental hydroxyapatite. The aim of this review is to assess the efficacy of this technology in terms of benefits for enamel and dentin and reduction of dental hypersensitivity.

MATERIALS AND METHODS

A literature search (Pubmed/MEDLINE and Scopus) of articles from 2003 to 2023 was conducted to analyze studies focused on the use of zinc-hydroxyapatite products. Duplicates were eliminated from the 5065 articles found, leaving 2076 articles. Of these, 30 articles were analyzed based on the use of products with zinc-carbonate hydroxyapatite in these studies.

RESULTS

30 articles were included. Most of the studies showed benefits in terms of remineralization and prevention of enamel demineralization in terms of occlusion of the dentinal tubules and reduction of dentinal hypersensitivity.

CONCLUSION

Oral care products such as toothpaste and mouthwash with biomimetic zinc-carbonate hydroxyapatite were shown to provide benefits according to the aims of this review.

Dental plaque-inspired versatile nanosystem for caries prevention and tooth restoration

Dental caries is one of the most prevalent human diseases resulting from tooth demineralization caused by acid production of bacteria plaque. It remains challenges for current practice to specifically identify, intervene and interrupt the development of caries while restoring defects. In this study, inspired by natural dental plaque, a stimuli-responsive multidrug delivery system (PMs@NaF-SAP) has been developed to prevent tooth decay and promote enamel restoration. Classic spherical core-shell structures of micelles dual-loaded with antibacterial and restorative agents are self-assembled into bacteria-responsive multidrug delivery system based on the pH-cleavable boronate ester bond, followed by conjugation with salivary-acquired peptide (SAP) to endow the nanoparticle with strong adhesion to tooth enamel. The constructed PMs@NaF-SAP specifically adheres to tooth, identifies cariogenic conditions and intelligently releases drugs at acidic pH, thereby providing antibacterial adhesion and cariogenic biofilm resistance, and restoring the microarchitecture and mechanical properties of demineralized teeth. Topical treatment with PMs@NaF-SAP effectively diminishes the onset and severity of caries without impacting oral microbiota diversity or surrounding mucosal tissues. These findings demonstrate this novel nanotherapy has potential as a promising biomedical application for caries prevention and tooth defect restoration while resisting biofilm-associated diseases in a controlled manner activated by pathological bacteria.

•

Nanomaterials can adhere to tooth and target acidic biofilms specifically.

•

Application of caries prevention and tooth defect restoration.

•

Guidance for the innovation of the existing post-defect restoration strategies.

•

The multidrug delivery system exerts antibacterial and restorative abilities on demand.

•

Bacteria-responsive system resists biofilm-associated diseases in a controlled manner.

Effects of bovine milk osteopontin on in vitro enamel remineralization as a topical application prior to immersion in remineralizing solutions with/without fluoride

The aim of the present study was to investigate the effects of bovine milk osteopontin (OPN) on enamel remineralization as a topical application prior to immersion in remineralizing solutions with/without fluoride. Bovine enamel blocks were demineralized then were divided into the following 3 groups: OPN (2.7 and 5.4 µM) solutions and deionized water (control). Each group was divided into 2 groups (remineralizing solution with or without 1 ppm of fluoride (F)). The specimens were analyzed by micro-CT and scanning electron microscope (SEM). The percentage of remineralization was higher in remineralization solution with than without F (p<0.05). The present results suggest that bovine milk OPN inhibits remineralization in solution without F, but 5.4 µM bovine milk OPN does not inhibit remineralization of the demineralized body using solution containing F by interrupting mineral deposition on the enamel surface.

In vitro determination of the remineralizing potential and cytotoxicity of non-fluoride dental varnish containing bioactive glass, eggshell, and eggshell membrane

PURPOSE

This study compares in vitro remineralization potential and cytotoxicity of fluoride-free varnish combinations containing bioactive glass, eggshell, and membrane powder and fluoride varnish formulations on artificial caries lesions.

METHODS

Artificial caries lesions were formed in two windows on third molars. One of the windows was coated with one of the following varnish formulations: FV (fluoride varnish), F-BAGV (fluoride and bioactive glass containing varnish), BAGV (bioactive glass containing varnish), EPV (eggshell powder containing varnish), EMP-EPV (eggshell membrane protein and eggshell powder containing varnish), STMP-EMP-EPV (sodium trimetaphosphate-treated eggshell membrane protein and eggshell powder containing varnish). The samples were remineralized, then investigated under scanning electron microscopy, and elemental analyses were performed by X-ray dispersive analysis (EDX). In addition, the traditional colorimetric tetrazolium-based reduction assay (XTT) and the modern impedance-based real-time cell analysis system (RTCA) were used to investigate their cytotoxicity.

RESULTS

The varnish applied area's Ca/P ratio was lower than stoichiometric hydroxyapatite except for EPV (1.66) and STMP-EMP-EPV (1.67) groups. Undiluted extracts of all varnishes, 1:2 dilutions of FV and F-BAGV groups were cytotoxic in XTT assay. In RTCA, the normalised cell index of the EMP-EPV and STMP-EMP-EPV groups was higher than the control group.

CONCLUSION

Bioactive glass, eggshell, eggshell membrane proteins and STMP-treated eggshell and eggshell membrane protein containing varnish have similar remineralizing effect to fluoride-containing varnish on demineralized enamel. Integrating biological or bioactive components instead of fluoride into the dental varnishes might reduce cytotoxicity.

Detection of Bacteria-Induced Early-Stage Dental Caries Using Three-Dimensional Mid-Infrared Thermophotonic Imaging

Tooth decay, or dental caries, is a widespread and costly disease that is reversible when detected early in its formation. Current dental caries diagnostic methods including X-ray imaging and intraoral examination lack the sensitivity and specificity required to routinely detect caries early in its formation. Thermophotonic imaging presents itself as a highly sensitive and non-ionizing solution, making it suitable for the frequent monitoring of caries progression. Here, we utilized a treatment protocol to produce bacteria-induced caries lesions. The lesions were imaged using two related three-dimensional photothermal imaging modalities: truncated correlation photothermal coherence tomography (TC-PCT) and its enhanced modification eTC-PCT. In addition, micro-computed tomography (μ-CT) and visual inspection by a clinical dentist were used to validate and quantify the severities of the lesions. The observational findings demonstrate the high sensitivity and depth profiling capabilities of the thermophotonic modalities, showcasing their potential use as a non-ionizing clinical tool for the early detection of dental caries.