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

Amphiphilic Janus nanoparticles for a superhydrophobic coating on the enamel surface to prevent caries

Bacteria are pivotal in the etiology of dental caries, underscoring the critical importance of effective plaque control in mitigating dental tissue diseases. Superhydrophobic materials, with their exceptional properties of non-wettability, antibacterial activity, and self-cleaning capabilities, present a promising approach for caries prevention. However, their clinical application remains constrained by challenges in achieving stable adhesion to tooth surfaces. Inspired by the natural adhesion mechanisms of acquired salivary pellicle (ASP), we synthesized Janus amphiphilic superhydrophobic nanoparticles comprising 1H,1H,2H,2H-perfluorooctyltriethoxysilane (FOTS), nano-silica, and the enamel binding peptide DDDEEKC-Peg(2000)-COOH. These nanoparticles were engineered to form a superhydrophobic film (FOTS-SiO2-Peptide) on tooth surfaces. Experimental analyses revealed rapid adsorption of these nanoparticles onto enamel, with their exposed surfaces creating a durable superhydrophobic layer that remained stable under diverse thermal conditions. Topical application of FOTS-SiO2-Peptide significantly reduced the incidence and severity of dental caries while preserving oral microbiota diversity and avoiding adverse effects on surrounding mucosal tissues. Safety and efficacy evaluations confirmed the biocompatibility of these Janus nanoparticles, highlighting their potential as a novel biomedical solution for caries prevention.

Saliva-acquired pellicle inspired multifunctional gargle with wet adhesion, photodynamic antimicrobial, and In situ remineralization properties for dental caries prevention

Dental caries is primarily caused by cariogenic bacteria metabolizing carbohydrates to produce acidic substances that erode the dental hard tissues. Traditional remineralization treatments often have limited efficacy due to their lack of antibacterial activity. According to the Interrupting Dental Caries (IDC) theory, ideal caries-preventive materials should possess both antibacterial and remineralizing properties. Furthermore, effective adhesion to dental surfaces is crucial. Inspired by the wet adhesion properties of the salivary acquired pellicle, we developed a multifunctional gargle named Ce6@PDN-SAP (CP-SAP). This formulation employed peptide dendrimer nanogels (PDN) as a carrier for the photosensitizer Ce6, further functionalized with saliva-acquired peptide (SAP) to confer wet adhesion properties. CP-SAP rapidly adhered to the dental surface and remained effective for extended periods. Upon laser irradiation, Ce6 generated reactive oxygen species (ROS), disrupting bacterial outer membrane integrity, causing protein leakage, and reducing ATP levels, thereby achieving potent antibacterial effects. Following this, PDN and SAP acted as nucleation templates to promote in situ remineralization of demineralized dental hard tissues. In vivo studies using rat models demonstrated that CP-SAP provided significantly superior caries-preventive effects compared to chlorhexidine gargle. In conclusion, CP-SAP, as an innovative approach grounded in the IDC theory, holds great promise for the prevention and treatment of dental caries.

Yellow light and ultrasound Dual-responsive strontium-doped zinc oxide composites for dental caries prevention and remineralization

Dental caries is one of the most prevalent chronic infectious diseases, mainly due to acid production by bacteria in the plaque biofilm, leading to enamel demineralization, tooth defects and pulpitis. Most of the current treatments are invasive and do not combine restoration of dental tissues, resolution of tooth staining or prevention of dental caries. In this study, a polydopamine (PDA)-encapsulated strontium-doped zinc oxide composite (Sr-ZnO@PDA, denoted as SZ@PDA) has been developed for caries prevention and remineralization. The PDA wrapping endows SZ@PDA with a narrow energy band gap (1.78 eV), which can simultaneously respond to yellow light (YL) with favorable biosafety and ultrasound (US) with high tissue penetration. The synergistic piezo-photocatalytic action of YL and US with the enhanced catalytic efficiency can generate an appropriate amount of reactive oxygen species (ROS), thus destroying the structure of bacterial cellular membranes and decomposing pigments for caries prevention and improvement of tooth staining, respectively. In addition, strontium ions (Sr2+) released by SZ@PDA, as an active element, can promote the remineralization of enamel and dentin, repairing defective dental tissues. Collectively, this versatile system (SZ@PDA) provides an effective strategy for the prevention and treatment of caries.

Antimicrobial, remineralization, and infiltration: advanced strategies for interrupting dental caries

Dental caries, driven by plaque biofilm, poses a major oral health challenge due to imbalance in mineralization and demineralization. The primary objective in caries management is to maintain biofilm homeostasis while facilitating the repair and regeneration of dental hard tissues, thus restoring both structural integrity and functionality of affected teeth. Though antimicrobial and remineralization approaches haven shown promise, their standalone utilization without concurrent bacterial control or rebalancing lacks an integrated strategy to effectively arrest caries progression. Furthermore, according to the principles of minimally invasive dentistry, treatment materials should exhibit high permeability to ensure optimal sealing of demineralized tooth surfaces. The concept of interrupting dental caries (IDC) has emerged as a holistic approach, drawing upon extensive research encompassing three pivotal techniques: antibacterial strategies, remineralization therapies, and infiltration mechanisms, all of which are indispensable components in combating the progression of dental caries. In this review, we provide a comprehensive overview of the mechanisms and applications of antibacterial, remineralization, and infiltration technologies within the context of caries management. Additionally, we summarize advanced materials that align with the IDC concept, aiming to offer valuable insights for designing next-generation materials adept at preventing or halting caries progression efficiently.

The advancement of nanosystems for drug delivery in the prevention and treatment of dental caries

The dental caries remains a globally prevalent disease. Although its incidence has decrease due to enhancements in sanitation policies and public health measures, the treatment and prevention of dental caries still pose significant challenges. Within the oral cavity, traditional drug delivery systems suffer from limitation such as inadequate tissue penetration, short duration of action at target site, and low specificity, which minimally affect the prevention and treatment of dental caries. Consequently, nanosystem for drug delivery, offering enhanced drug stability, solubility, and bio-availability while reducing side effects, garnering attention increasing attention in the fight against dental caries. Therefore, this review examines the role of nanosystems for drug delivery in combating dental caries by inhibiting bacteria survival, biofilm formation, demineralization, and promoting remineralization, and exploring their potential to become the mainstream means of prevention and treatment of dental caries in future.

Layer-by-layer coated probiotics with tannic acid-Ca2+ and casein phosphopeptide complexes for caries prevention and enamel remineralization

Dental caries is a common disease resulting from tooth demineralization caused by bacterial plaque. Probiotics have shown great potential against caries by regulating the balance of oral flora. However, obstacles such as poor colonization and lysozyme sensitivity in oral cavity hinder their further application. In this study, an efficient layer-by-layer surface coating of tannic acid (TA)-Ca2+ and casein phosphopeptide (CPP) was applied to the probiotic Bifidobacterium infantis (BI) with potential anti-caries activity. Multi-functionalized probiotics thus prepared (called BI@TA-Ca2+@CPP) exhibited similar growth pattern, resistance to lysozyme and enhanced colonization potential. The ability of BI@TA-Ca2+@CPP in inhibiting cariogenic biofilm formation was improved. Moreover, BI@TA-Ca2+@CPP showed excellent remineralization efficacy. In a caries-induced rat model, BI@TA-Ca2+@CPP significantly prevented the occurrence and progression of tooth decay, meanwhile showing good biocompatibility. In summary, this study underlines the importance of probiotics coating in antibiofilm and remineralization activity as a promising strategy against dental caries.

Antibacterial and Antileishmanial Activity of 1,4-Dihydropyridine Derivatives

We have synthesized twenty-three 1,4-dihydropyridine derivatives (1,4-DHPs) by using a microwave-assisted one-pot multicomponent Hantzsch reaction and evaluated their antibacterial activity against a representative panel of cariogenic bacteria and their in vitro antileishmanial activity against Leishmania (L.) amazonensis promastigotes and amastigotes. Thirteen compounds were moderately active against Streptococcus sanguinis, Streptococcus mitis, and Lactobacillus paracasei. Compound 22 (diethyl 4-(3-methoxy-4-hydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate) displayed moderate antibacterial activity against S. mitis and S. sanguinis, with a Minimum Inhibitory Concentration (MIC) of 500 μg/mL); compounds 8 (ethyl 2,7,7-trimethyl-4-(3-chlorophenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate) and 10 (ethyl 2,7,7-trimethyl-4-(3-nitrophenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate) were moderately active against S. sanguinis (MIC=500 μg/mL) and very active against L. amazonensis promastigotes (IC50=43.08 and 34.29 μM, respectively). Among the eight 1,4-DHPs that were active (IC50 <50 μM) against L. amazonensis promastigotes, compound 13 (ethyl 2,7,7-trimethyl-4-(3,4,5-trimethoxyphenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate) was the most active (IC50=24.62 μM) and had a Selectivity Index (SI) higher than 4 compared to GM07492 A cells. On the other hand, compounds 7 (ethyl 2,7,7-trimethyl-4-(3-fluorophenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate) and 9 (ethyl 2,7,7-trimethyl-4-(2-nitrophenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate) were the most active against L. amazonensis amastigotes (IC50=12.53 and 13.67 μM, respectively; SI>7.9 and >7.3, respectively) after 24 h of treatment. Our results indicated that asymmetric 1,4-DHPs derived from dimedone exhibit antileishmanial potential.

Constructing two bifunctional tooth-targeting antimicrobial peptides for caries management: an in vitro study

OBJECTIVES

Caries is a significant public health challenge. Herein, novel tooth-targeting antimicrobial peptides (HABPs@AMPs) were developed by combining the antimicrobial peptide DJK-5 with hydroxyapatite (HA) binding peptides, providing a potential new strategy for caries management.

MATERIALS AND METHODS

The minimal inhibitory concentration (MIC100) and minimal biofilm inhibitory concentration (MBIC100) values of HABPs@AMPs were determined via micro-broth dilution and crystal violet staining. The affinities of the peptides for HA were measured by mass depletion, and the abilities of peptides to inhibit Streptococcus mutans (S. mutans) biofilm formation and kill 3-day-old S. mutans biofilms were evaluated in HA disk and tooth slice biofilm models through confocal laser scanning microscopy. Biocompatibility with human gingival fibroblasts was evaluated via CCK8 assays.

RESULTS

The best performing peptides, DJK-5@SVA and SVA@DJK-5 exhibited MIC100 and MBIC100 values of 31.25 µg/mL, similar to DJK-5. DJK-5@linker2@YSL had the highest affinity for HA, followed by YSL@DJK-5, DJK-5@linker1@YSL, and DJK-5@SVA. Moreover, the biofilms on HABPs@DJK-5 coated surfaces had more dead bacteria by volume than those in the DJK-5 and SVA groups (p < 0.05). DJK-5@SVA outperformed SVA@DJK-5 and DJK-5 in killing 3-day-old S. mutans biofilms (p < 0.05). With the exception of established biofilms on tooth slices, DJK-5@SVA exhibited greater killing efficiency in the bottom half of the biofilms than in the top half. The CCK-8 assay results confirmed peptides' biocompatibility.

CONCLUSIONS

DJK-5@SVA with good affinity for HA, has excellent biocompatibility and efficacy against S. mutans biofilms.

CLINICAL RELEVANCE

HABPs@AMPs with effective inhibitory effects on the growth of S. mutans and biofilm formation, contributing to intraoral targeted application AMPs and providing a new strategy for caries management.

Black Phosphorus Nanosheets-Loaded Mussel-Inspired Hydrogel with Wet Adhesion, Photothermal Antimicrobial, and In Situ Remineralization Capabilities for Caries Prevention

The main features of early caries are the massive colonization of cariogenic bacteria and demineralization of tooth enamel by the acids that they produce. Owing to the lack of effective treatments, the development of anticaries therapeutics with both antimicrobial and remineralizing properties is urgently required. Black phosphorus nanosheets (BPNs) are ideal therapeutics for the treatment of early caries because they can mediate photothermal antibacterial activity and subsequently promote remineralization by generating PO4 3-. However, the dynamic and wet environment of the oral cavity prevents the long-term adhesion of BPNs to the tooth surface. In this study, using catechol-modified chitosan and PLGA-PEG-PLGA as raw materials, a mussel-inspired versatile hydrogel, BP@CP5, is presented that can be used to physically load BPNs. BP@CP5 has exceptional injectability and can firmly adhere to tooth surfaces for up to 24 h. Upon irradiation, BP@CP5 can quickly eliminate ≈99% of Streptococcus mutans and Streptococcus sanguinis; furthermore, the PO4 3- generated via degradation also promotes rapid remineralization of enamel slabs. Importantly, the vivo rodent caries modeling results further confirm the excellent caries-prevention properties of BP@CP5. This study demonstrates that BP@CP5 is a promising anticaries material for caries management.

Unraveling Nanomaterials in Biomimetic Mineralization of Dental Hard Tissue: Focusing on Advantages, Mechanisms, and Prospects

The demineralization of dental hard tissue imposes considerable health and economic burdens worldwide, but an optimal method that can repair both the chemical composition and complex structures has not been developed. The continuous development of nanotechnology has created new opportunities for the regeneration and repair of dental hard tissue. Increasingly studies have reported that nanomaterials (NMs) can induce and regulate the biomimetic mineralization of dental hard tissue, but few studies have examined how they are involved in the different stages, let alone the relevant mechanisms of action. Besides their nanoscale dimensions and excellent designability, NMs play a corresponding role in the function of the raw materials for mineralization, mineralized microenvironment, mineralization guidance, and the function of mineralized products. This review comprehensively summarizes the advantages of NMs and examines the specific mineralization mechanisms. Design strategies to promote regeneration and repair are summarized according to the application purpose of NMs in the oral cavity, and limitations and development directions in dental hard tissue remineralization are proposed. This review can provide a theoretical basis to understand the interaction between NMs and the remineralization of dental hard tissue, thereby optimizing design strategy, rational development, and clinical application of NMs in the field of remineralization.

Biofilm formation of Streptococcus mutans, Streptococcus sanguinis, Staphylococcus epidermidis, Staphylococcus aureus, Lactobacillus casei, and Candida Albicans on 5 thermoform and 3D printed orthodontic clear aligner and retainer materials at 3 time points: an in vitro study

INTRODUCTION

Orthodontic clear aligners and retainers have numerous advantages that is making them ever increasingly popular. However, they might, similar to any other oral appliance, contribute to biofilm formation and finally dental caries or white spot lesions or gingival inflammations. The literature on biofilm formation on orthodontic clear appliances is very scarce and limited to a few microorganisms and materials. Therefore, this experimental study evaluated the biofilm formation on 5 thermoformed and 3D printed CAD/CAM orthodontic retainers in 3 intervals.

METHODS

In this in vitro study, 345 specimens (270 test discs and 45 negative controls) were created from fabricated retainers. Retainers included a 3D printed CAD/CAM material (Detax) and four thermoformed retainers [Erkodent (polyethylene terephthalate glycol [PETG]); EasyVac (polyethylene); DB (polyester based on terephthalic acid); and Clear Tech]. They were all 1 mm thick, and all completely fabricated, i.e., heated or printed. The discs were placed in 96-well plates. Microorganisms were cultured on 270 discs for 24 h (90 discs), 72 h (90 other discs), and 5 days or 120 h (90 other discs). Biofilm formation of the strains and negative controls was measured using the microtiter plate assay by ELISA reading. The microbes' ability to produce biofilm was categorized based on the comparison of average optical density (OD) of tests versus a cut-off point OD (ODc) calculated as the average of the OD of corresponding negative controls plus 3× its standard deviation: non-biofilm former [OD ≤ ODc], weak biofilm former [ODc < OD ≤ (2 × ODc)], moderate biofilm former [(2 × ODc) < OD ≤ (4 × ODc)], and strong biofilm former [(4 × ODc) < OD]. These were also converted to ranked scores between zero (no biofilm) and 3. The difference between ODs with control ODs were calculated. These were analyzed using 3-way ANOVA, 2-way ANOVA, and Tukey tests (α = 0.05, α = 0.008).

RESULTS

The 3-way ANOVA showed that the overall difference among the ΔODs of 5 retainers (all microorganisms and all intervals combined, n = 270) was not significant (F = 1.860, P = 0.119). Nevertheless, the difference among 3 intervals (F = 31.607, P = 0.0000) and the difference among the 6 microorganisms (F = 24.044, P = 0.0000) were significant. According to the Tukey test, the differences between the 1st interval with either of the other two intervals was significant (both P values = 0.000). There were significant differences between Candida albicans with all other organisms (all 5 P values = 0.0000). All other pairwise comparisons were insignificant (all 10 P values ≥ 0.1). After taking the averages of the 3 intervals, the order of the biofilm generation for different materials were as follows: Detax (average score: 1.56), Easyvac (1.67), Erkodent (1.78), Clear Tech (1.83), BD (2.28).

CONCLUSIONS

As far as these 6 microorganisms are of concern, there might not be a significant overall difference among the clear retainer materials tested in this study. A significant overall increase was observed between the first and third days, which later did not significantly increase more until day 5. The Candida albicans biofilm was more intense than the tested 5 bacteria, which themselves showed rather similar growth patterns to each other.

Advances in hybridized nanoarchitectures for improved oro-dental health

On a global note, oral health plays a critical role in improving the overall human health. In this vein, dental-related issues with dentin exposure often facilitate the risk of developing various oral-related diseases in gums and teeth. Several oral-based ailments include gums-associated (gingivitis or periodontitis), tooth-based (dental caries, root infection, enamel erosion, and edentulous or total tooth loss), as well as miscellaneous diseases in the buccal or oral cavity (bad breath, mouth sores, and oral cancer). Although established conventional treatment modalities have been available to improve oral health, these therapeutic options suffer from several limitations, such as fail to eradicate bacterial biofilms, deprived regeneration of dental pulp cells, and poor remineralization of teeth, resulting in dental emergencies. To this end, the advent of nanotechnology has resulted in the development of various innovative nanoarchitectured composites from diverse sources. This review presents a comprehensive overview of different nanoarchitectured composites for improving overall oral health. Initially, we emphasize various oral-related diseases, providing detailed pathological circumstances and their effects on human health along with deficiencies of the conventional therapeutic modalities. Further, the importance of various nanostructured components is emphasized, highlighting their predominant actions in solving crucial dental issues, such as anti-bacterial, remineralization, and tissue regeneration abilities. In addition to an emphasis on the synthesis of different nanostructures, various nano-therapeutic solutions from diverse sources are discussed, including natural (plant, animal, and marine)-based components and other synthetic (organic- and inorganic-) architectures, as well as their composites for improving oral health. Finally, we summarize the article with an interesting outlook on overcoming the challenges of translating these innovative platforms to clinics.

Trans-Cinnamaldehyde Inhibition of Pyruvate Dehydrogenase: Effects on Streptococcus mutans Carbohydrate Metabolism

Dental caries is a chronic oral infectious disease, and Streptococcus mutans (S. mutans) plays an important role in the formation of dental caries. Trans-cinnamaldehyde (CA) exhibits broad-spectrum antibacterial activity; however, its target and mechanism of action of CA on S. mutans needs to be further explored. In this study, it was verified that CA could inhibit the growth and biofilm formation of S. mutans. Further proteomic analysis identified 33, 55, and 78 differentially expressed proteins (DEPs) in S. mutans treated with CA for 1, 2, and 4 h, respectively. Bioinformatics analysis showed that CA interfered with carbohydrate metabolism, glycolysis, pyruvate metabolism, and the TCA cycle, as well as amino acid metabolism of S. mutans. Protein interactions suggested that pyruvate dehydrogenase (PDH) plays an important role in the antibacterial effect of CA. Moreover, the upstream and downstream pathways related to PDH were verified by various assays, and the results proved that CA not only suppressed the glucose and sucrose consumption and inhibited glucosyltransferase (GTF) and lactate dehydrogenase (LDH) activities but also decreased the ATP production. Interestingly, the protein interaction, qRT-PCR, and molecular docking analysis showed that PDH might be the target of CA to fight S. mutans. In summary, the study shows that CA interferes with the carbohydrate metabolism of bacteria by inhibiting glycolysis and the tricarboxylic acid (TCA) cycle via binding to PDH, which verifies that PDH is a potential target for the development of new drugs against S. mutans.

Chitosan Phytate Nanoparticles: A Synergistic Strategy for Effective Dental Caries Prevention

Dental caries is a widespread oral disease that poses a significant medical challenge. Traditional caries prevention methods, primarily the application of fluoride, often fall short in effectively destroying biofilms and preventing enamel demineralization, thereby providing limited efficacy in halting the progression of caries over time. To address this issue, we have developed a green and cost-effective synergistic strategy for the prevention of dental caries. By combining natural sodium phytate and chitosan, we have created chitosan-sodium phytate nanoparticles that offer both the antimicrobial properties of chitosan and the enamel demineralization-inhibiting capabilities of sodium phytate. In an ex vivo biofilm model of human teeth, we found that these nanoparticles effectively prevent biofilm buildup and acid damage to the mineralized tissue. Additionally, topical treatment of dental caries in rodent models has shown that these nanoparticles effectively suppress disease progression without negatively impacting oral microbiota diversity or causing harm to the gingival-mucosal tissues, unlike traditional prevention methods.

Urchin-like multiscale structured fluorinated hydroxyapatite as versatile filler for caries restoration dental resin composites

Caries is one of the most prevalent human diseases, resulting from demineralization of tooth hard tissue caused by acids produced from bacteria, and can progress to pulpal inflammation. Filling restoration with dental resin composites (DRCs) is currently the most common treatment for caries. However, existing DRCs suffer from low fracture strength and lack comprehensive anti-caries bioactivity including remineralization, pulp protection, and anti-cariogenic bacteria effects. In this study, inspired by plant roots' ability to stabilize and improve soil, fluorinated urchin-like hydroxyapatite (FUHA) with a three-dimensional whisker structure and bioactive components of calcium, phosphorus, and fluorine was designed and synthesized by a dynamic self-assembly method. Furthermore, versatile FUHA particles with different loading fractions were used as functional fillers to fabricate methacrylate-based DRCs, where the urchin-like hydroxyapatite (UHA) filled DRCs and commercial DRCs (Z350XT and BEAUTIFIL II) served as the control groups. The results demonstrated that FUHA with 50 wt% loading in resin matrix endowed DRC (F5) with excellent physicochemical properties, dentin remineralization property, cell viability, promotion of dental pulp stem cells mineralization, and antibacterial properties. Meanwhile, F5 also presented good clinical handling and aesthetic characteristics. Therefore, structure/functional-integrated FUHA filled DRCs have potential as a promising strategy for tooth restoration and anti-caries bioactivity.

Integrating Artificial DNAzymes with Natural Enzymes on 2D MOF Hybrid Nanozymes for Enhanced Treatment of Bacteria-Infected Wounds

Removal of invasive bacteria is critical for proper wound healing. This task is challenging because these bacteria can trigger intense oxidative stress and gradually develop antibiotic resistance. Here, the use of a multienzyme-integrated nanocatalytic platform is reported for efficient bacterial clearance and mitigation of inflammatory responses, constructed by physically adsorbing natural superoxide dismutase (SOD), in situ reduction of gold nanoparticles (Au NPs), and incorporation of a DNAzyme on 2D NiCoCu metal-organic frameworks (DNAzyme/SOD/Au@NiCoCu MOFs, termed DSAM), which can adapt to infected wounds. O2 and H2O2 replenishment is achieved and alleviated the hypoxic microenvironment using the antioxidant properties of SOD. The H2O2 produced during the reaction is decomposed by peroxidase (POD)-like activity enhanced by Au NPs and DNAzyme, releasing highly toxic hydroxyl radicals (•OH) to kill the bacteria. In addition, it possesses glutathione peroxidase (GPx)-like activity, which depletes GSH and prevents •OH loss. Systematic antimicrobial tests are performed against bacteria using this multienzyme-integrated nanoplatform. A dual-mode strategy involving natural enzyme-enhanced antioxidant capacity and artificial enzyme-enhanced •OH release to develop an efficient and novel enzyme-integrated therapeutic platform is integrated.

Hard tissue formation in pulpotomized primary teeth in dogs with nanomaterials MCM-48 and MCM-48/hydroxyapatite: an in vivo animal study

BACKGROUND

This animal study sought to evaluate two novel nanomaterials for pulpotomy of primary teeth and assess the short-term pulpal response and hard tissue formation in dogs. The results were compared with mineral trioxide aggregate (MTA).

METHODS

This in vivo animal study on dogs evaluated 48 primary premolar teeth of 4 mongrel female dogs the age of 6-8 weeks, randomly divided into four groups (n = 12). The teeth underwent complete pulpotomy under general anesthesia. The pulp tissue was capped with MCM-48, MCM-48/Hydroxyapatite (HA), MTA (positive control), and gutta-percha (negative control), and the teeth were restored with intermediate restorative material (IRM) paste and amalgam. After 4-6 weeks, the teeth were extracted and histologically analyzed to assess the pulpal response to the pulpotomy agent.

RESULTS

The data were analyzed using the Kruskal‒Wallis, Fisher's exact, Spearman's, and Mann‒Whitney tests. The four groups were not significantly different regarding the severity of inflammation (P = 0.53), extent of inflammation (P = 0.72), necrosis (P = 0.361), severity of edema (P = 0.52), extent of edema (P = 0.06), or connective tissue formation (P = 0.064). A significant correlation was noted between the severity and extent of inflammation (r = 0.954, P < 0.001). The four groups were significantly different regarding the frequency of bone formation (P = 0.012), extent of connective tissue formation (P = 0.047), severity of congestion (P = 0.02), and extent of congestion (P = 0.01). No bone formation was noted in the gutta-percha group. The type of newly formed bone was not significantly different among the three experimental groups (P = 0.320).

CONCLUSION

MCM-48 and MCM-48/HA are bioactive nanomaterials that may serve as alternatives for pulpotomy of primary teeth due to their ability to induce hard tissue formation. The MCM-48 and MCM-48/HA mesoporous silica nanomaterials have the potential to induce osteogenesis and tertiary (reparative) dentin formation.

Polyelectrolyte-Cation Complexes Using PAsp-Sr Complexes Induce Biomimetic Mineralization with Antibacterial Ability

Remineralized dentin with an antibacterial ability is still a significant challenge in dentistry. Previously, a polyelectrolyte-calcium complexes pre-precursor (PCCP) process is proposed for rapid collagen mineralization. In the present study, the expansion concept of the PCCP process is explored by replacing the calcium with other cations, such as strontium. The results of transmission electron microscopy (TEM), 3D stochastic optical reconstruction microscopy, energy-dispersive X-ray analysis, Fourier transform infrared spectroscopy, and high-resolution TEM with selected area electron diffraction demonstrate that biomimetic mineralization of collagen fibrils and demineralized dentin could be fulfilled with Sr&F-codoped hydroxyapatite (HAp) after they are treated with poly-aspartic acid-strontium (PAsp-Sr) suspension followed by a phosphate&fluoride solution. Moreover, dentin remineralized with Sr&F-codoped HAp exhibits in vitro and in vivo antibacterial ability against Streptococcus mutans. The cytotoxicity and oral mucosa irritation tests reveal excellent biocompatibility of mineralization mediums (PAsp-Sr suspension and phosphate&fluoride solution). The demineralized dentin's mechanical properties (elastic modulus and microhardness) could be restored almost to that of the intact dentin. Hence, the expansion concept of the PCCP process that replaces calcium ions with some cationic ions along with fluorine opens up new horizons for generating antibacterial remineralized dentin containing ions-doped HAp with excellent biocompatibility via biomimetic mineralization technology.

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

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

Assessment of Decision-Making and Material Selection for Vital Pulp Therapy in Deep Carious Lesions: A Study at the Faculty of Dentistry, King Abdulaziz University

PURPOSE

The purposes of this study were to assess decision-making, material selection, and management of deep carious lesions in permanent teeth requiring vital pulp therapy (VPT); investigate the intradepartmental and interdepartmental consensus in the management of those cases; and correlate this study's results to the current scientific literature, clinical experience, and postgraduate training among staff and postgraduate students at the Faculty of Dentistry, King Abdulaziz University.

MATERIALS AND METHODS

The survey included faculty from pedodontics, endodontics, and restorative/operative dentistry; postgraduate students; and interns, excluding specific categories such as retired faculty, external trainers, non-faculty hospital specialists, general practitioners, students, interns outside the institution, and other departments. An anonymous electronic questionnaire was developed and validated. Ethical approval was obtained, and the questionnaire was distributed to all 148 English-proficient members of the targeted population via email and WhatsApp, accompanied by a cover letter. The questionnaire encompassed demographic, education, experience, assessment, decision-making, and management sections. Data were collected and analyzed using Microsoft Excel, with results presented using categorical variables, Pareto charts, and statistical tests.

RESULTS

There were 86 responses, representing 58% of the target population, with the key findings including the prominence of "Pre-operative vitality test result" as the most important factor in assessing deep carious lesions, with no significant differences among specialties. The (one-step and one-visit) management approach was preferred by 50% of participants, with no significant specialty differences. For deep carious lesions without pulpal exposure, glass ionomer (GI)/resin-modified glass ionomer (RMGI) base was the top choice, with no variation among all specialties. In cases with pulpal exposure, the one-visit approach (direct pulp capping (DPC), base, and restoration) was the most favored, with no specialty differences. Material availability significantly influenced decision-making, with no specialty variations.

CONCLUSION

The study highlights the crucial role of pre-operative vitality tests in assessing deep carious lesions for VPT or root canal treatment (RCT). Participants generally favored VPT for cases with normal pulp vitality, with some departmental variation. Controlling bleeding post-pulpal exposure was a central concern. Mineral trioxide aggregate (MTA) was the most commonly used VPT material, followed by Ca(OH)2 and Biodentine. Factors such as treatment access, patient compliance, remaining dentin thickness, and oral hygiene had minimal impact on treatment choice. Limited availability of VPT materials was the primary reason for non-use. The survey's acceptable response rate raises concerns about potential non-response bias, though limitations include a lack of data on non-responders. Nevertheless, the survey's strength lies in its comprehensive coverage of key clinical aspects, engaging professionals from diverse specialties and educational levels who are collectively interested in addressing deep caries cases.

Full Pulpotomy as a Treatment for Irreversible Pulpitis in Permanent Teeth: A Systematic Review of the Literature Based on Case Reports

The objective of this systematic review was to evaluate the current evidence of case reports where the treatment for permanent teeth with a diagnosis of irreversible pulpitis was a full pulpotomy. This study was carried out by two reviewers following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. A systematic electronic search was carried out in the PubMed, Google Scholar, and Scopus databases until the year 2022 to find articles in English where the treatment for irreversible pulpitis in permanent teeth was a full pulpotomy. Literature reviews, in vitro or animal studies, abstracts, and unpublished data were excluded. The intervention, control, and outcome parameters were selected following the "Population, Interventions, Control, and Outcome" (PICO) guidelines. A total of 636 articles were found, and 14 articles were selected to be included in this review. The selected articles describe cases of full pulpotomies in mature permanent teeth with a diagnosis of irreversible pulpitis with a total of 34 (100%) successful cases, where 18 were men and 16 were women, with an average age of 19.20 ± 10.59 years and an average follow-up of 35.82 ± 26.39 months, with 12 months being the minimum follow-up time. The material used most frequently for obturation of the full pulpotomy was mineral trioxide aggregate in 16 cases (47.06%). Within the limitations of this review, full pulpotomy presents a high success rate regardless of the tooth, age, or sex as a treatment for teeth diagnosed with irreversible pulpitis.

Drug delivery strategies for antibiofilm therapy

Although new antibiofilm agents have been developed to prevent and eliminate pathogenic biofilms, their widespread clinical use is hindered by poor biocompatibility and bioavailability, unspecific interactions and insufficient local concentrations. The development of innovative drug delivery strategies can facilitate penetration of antimicrobials through biofilms, promote drug dispersal and synergistic bactericidal effects, and provide novel paradigms for clinical application. In this Review, we discuss the potential benefits of such emerging techniques for improving the clinical efficacy of antibiofilm agents, as well as highlighting the existing limitations and future prospects for these therapies in the clinic.

Influence of Sucrose and Arenga pinnata Solutions on Enamel Surface Demineralization: A Profilometric Study

Background Dental caries is a multifactorial disease that has the potential to impact individuals across various life stages. The influential role of sugar as a contributing risk element in the inception and advancement of dental caries is significantly pronounced.  Aim The research aim was to analyze and compare the enamel surface roughness in teeth exposed to sucrose and Arenga pinnata (palm sugar) solutions by using a stylus profilometer Materials and methods In this investigation, 34 freshly extracted anterior teeth were obtained and they were split into two groups depending on the solution in which they were immersed. Group A consists of 17 teeth immersed in 1% sucrose solution supplemented in brain heart infusion (BHI) broth solution and Group B consists of 17 teeth immersed in 1% Arenga pinnata BHI broth. Each sample served as its own control. Streptococcus mutans was inoculated into these groups and they were immersed in their respective solution for five days. A stylus profilometer was utilized to measure the surface roughness of the teeth in this study. Data analysis involved paired t-tests for intragroup comparisons and independent t-tests for intergroup comparisons using SPSS software version 23. Results After five days of exposure to palm sugar or sucrose, it was observed that there was demineralization of the enamel surface on both samples. Although there was no statistical significance (p<0.05) when an independent t-test was conducted among these samples, there was a visible increase in the numerical values of Ra, Rq, Rz of teeth exposed to sucrose compared to palm sugar with a p-value of 0.529, 0.122 and 0.357, respectively. Conclusion From this study, it was concluded that although both sucrose and Arenga pinnata cause demineralization of enamel, it was shown that the latter caused lesser demineralization when compared to refined sugars to a certain extent. This study establishes a foundation for forthcoming investigations that could potentially explore the utilization of natural sugars as a substitute for sucrose, while also evaluating the mechanistic aspects underlying the impact of these sugars on enamel demineralization.

Engineered Biomaterials Trigger Remineralization and Antimicrobial Effects for Dental Caries Restoration

Dental caries is the most prevalent chronic disease globally, significantly impacting individuals' quality of life. A key reason behind the failure of implanted restorations is their biological inactivity, meaning they are unable to form crosslinks with the surrounding tooth structures, thus making patients susceptible to implant loss and recurrent tooth decay. For the treatment of caries, antibacterial medicine and remineralization are effective means of treating the recurrence of caries. Owing to the rapid progression in the biomaterials field, several biomaterials have been reported to display antimicrobial properties and aid in dentin remineralization. Bioactive materials hold considerable potential in diminishing biofilm accumulation, inhibiting the process of demineralization, enabling dentin remineralization, and combating bacteria related to caries. Bioactive materials, such as fluoride, amorphous calcium phosphate, bioactive glass, collagen, and resin-based materials, have demonstrated their effectiveness in promoting dentin remineralization and exerting antibacterial effects on dental caries. However, the concentration of fluoride needs to be strictly controlled. Although amorphous calcium phosphate can provide the necessary calcium and phosphorus ions for remineralization, it falls short in delivering the mechanical strength required for oral mastication. Resin-based materials also offer different advantages due to the complexity of their design. In this review, we delve into the application of advanced bioactive materials for enhancing dentin remineralization and antibacterial properties. We eagerly anticipate future developments in bioactive materials for the treatment of dental caries.

An epigallocatechin gallate-amorphous calcium phosphate nanocomposite for caries prevention and demineralized enamel restoration

Biomineralization with amorphous calcium phosphate (ACP) is a highly effective strategy for caries prevention and defect restoration. The identification and interruption of cariogenic biofilm formation during remineralization remains a challenge in current practice. In this study, an epigallocatechin gallate (EGCG)-ACP functional nanocomposite was developed to prevent and restore demineralization by integrating the antibacterial property of EGCG and the remineralization effect of ACP. The synthesized EGCG-ACP showed good biocompatibility with L-929 ​cells and human gingival fibroblasts. Under neutral conditions, the sustained release of ACP from EGCG-ACP restored the microstructure and mechanical properties of demineralized enamel. Under acidic conditions, protonated EGCG released from EGCG-ACP exerted a strong antibacterial effect, and the ACP release rate doubled within 4 ​h, resulting in the prevention of demineralization in the presence of cariogenic bacteria. The pH-responsive features of EGCG-ACP to promote the protonation of EGCG and ACP release facilitated its performance in remineralization effect to overcome the difficulty of restoring demineralized enamel in a cariogenic acidic environment, which was evidenced by the in vivo experiment carried out in a rat oral cariogenic environment. The results of this study indicate the potential of EGCG-ACP for the prevention of enamel demineralization and provide a theoretical basis its application in populations with high caries risk.

Transforming Dental Caries Diagnosis Through Artificial Intelligence-Based Techniques

Diagnosing dental caries plays a pivotal role in preventing and treating tooth decay. However, traditional methods of diagnosing caries often fall short in accuracy and efficiency. Despite the endorsement of radiography as a diagnostic tool, the identification of dental caries through radiographic images can be influenced by individual interpretation. Incorporating artificial intelligence (AI) into diagnosing dental caries holds significant promise, potentially enhancing the precision and efficiency of diagnoses. This review introduces the fundamental concepts of AI, including machine learning and deep learning algorithms, and emphasizes their relevance and potential contributions to the diagnosis of dental caries. It further explains the process of gathering and pre-processing radiography data for AI examination. Additionally, AI techniques for dental caries diagnosis are explored, focusing on image processing, analysis, and classification models for predicting caries risk and severity. Deep learning applications in dental caries diagnosis using convolutional neural networks are presented. Furthermore, the integration of AI systems into dental practice is discussed, including the challenges and considerations for implementation as well as ethical and legal aspects. The breadth of AI technologies and their prospective utility in clinical scenarios for diagnosing dental caries from dental radiographs is presented. This review outlines the advancements of AI and its potential in revolutionizing dental caries diagnosis, encouraging further research and development in this rapidly evolving field.

Evaluation of the Prevalence of White Spot Lesions During Fixed Orthodontic Treatment Among Patients Reporting for Correction of Malocclusion: A Prevalence Study

BACKGROUND

Despite recent breakthroughs in caries preventive measures, one of the biggest issues clinicians confront is preventing demineralization while undergoing orthodontic therapy. The buildup of plaques around orthodontic brackets over time causes white spot lesions (WSLs). The goal of the present research was to assess the prevalence of WSLs in patients undergoing orthodontic treatment before starting therapy and at six and 12 months into therapy, adopting the visual examination approach.

MATERIALS AND METHODS

We looked for WSLs on tooth surfaces gingival to an archwire because this is the area most likely to experience enamel demineralization during orthodontic treatment. The visual assessment was conducted using the following scale at baseline, six months, and 12 months for orthodontic patients: score 0: no demineralization or noticeable white patches on the surface; score 1: mild demineralization with a visible white spot but no surface disruption; score 2: moderate demineralization with a noticeable WSL that has a roughened surface but does not need repair; and score 3: severe demineralization with a noticeable WSL that needs repair. Fisher's exact test was used after a chi-square analysis to determine whether there were any differences between all three categories (six months, 12 months, and control).

RESULTS

The frequency of WSL in patients at 12 months of orthodontic treatment was 46.57%, while it was 11.86% in patients who just started orthodontic treatment. The difference was statistically significant (p = 0.01), showing that the frequency was greater in patients at 12 months of orthodontic treatment as compared to patients who had just started undergoing orthodontic treatment. The frequency of WSL in patients at six months of orthodontic treatment was 37.34%, while it was 11.86% in patients who just started orthodontic treatment. The difference was statistically significant (p = 0.03), showing that the frequency was greater in patients at six months of orthodontic treatment as compared to patients who had just started undergoing orthodontic treatment. The frequency of WSL in patients at six months of orthodontic treatment was 37.34%, while it was 46.57% in patients at 12 months of orthodontic treatment. The frequency was greater in patients at 12 months of orthodontic treatment as compared to patients at six months of orthodontic treatment; however, the difference was non-significant statistically (p = 0.76).

CONCLUSION

This clinical investigation revealed that the number of WSLs increased significantly during the first six months of treatment and then increased gradually until the final 12 months. During the first few months of treatment, doctors should assess the patients' dental hygiene habits and, if necessary, take further precautions to prevent demineralization.

pH-Responsive Biomaterials for the Treatment of Dental Caries-A Focussed and Critical Review

Dental caries is a common and costly multifactorial biofilm disease caused by cariogenic bacteria that ferment carbohydrates to lactic acid, demineralizing the inorganic component of teeth. Therefore, low pH (pH 4.5) is a characteristic signal of the localised carious environment, compared to a healthy oral pH range (6.8 to 7.4). The development of pH-responsive delivery systems that release antibacterial agents in response to low pH has gained attention as a targeted therapy for dental caries. Release is triggered by high levels of acidogenic species and their reduction may select for the establishment of health-associated biofilm communities. Moreover, drug efficacy can be amplified by the modification of the delivery system to target adhesion to the plaque biofilm to extend the retention time of antimicrobial agents in the oral cavity. In this review, recent developments of different pH-responsive nanocarriers and their biofilm targeting mechanisms are discussed. This review critically discusses the current state of the art and innovations in the development and use of smart delivery materials for dental caries treatment. The authors' views for the future of the field are also presented.

Smart Dental Materials Intelligently Responding to Oral pH to Combat Caries: A Literature Review

Smart dental materials are designed to intelligently respond to physiological changes and local environmental stimuli to protect the teeth and promote oral health. Dental plaque, or biofilms, can substantially reduce the local pH, causing demineralization that can then progress to tooth caries. Progress has been made recently in developing smart dental materials that possess antibacterial and remineralizing capabilities in response to local oral pH in order to suppress caries, promote mineralization, and protect tooth structures. This article reviews cutting-edge research on smart dental materials, their novel microstructural and chemical designs, physical and biological properties, antibiofilm and remineralizing capabilities, and mechanisms of being smart to respond to pH. In addition, this article discusses exciting and new developments, methods to further improve the smart materials, and potential clinical applications.

Dynamic killing effectiveness of mouthrinses and a D-enantiomeric peptide on oral multispecies biofilms grown on dental restorative material surfaces

OBJECTIVE

To evaluate the dynamics of killing of oral multispecies biofilms grown on dental restorative materials by commercially available mouthrinses and a D-enantiomeric peptide.

METHODS

Four composite resins (3M Supreme, 3M Supreme flow, Kerr Sonicfill, and Shofu Beautifil II) and one glass ionomer (GC Fuji II) were used as restorative materials. Plaque biofilms were grown on the surfaces of restorative material discs for 1 week. The surface roughness and biofilm attachment were assessed by atomic force microscopy and scanning electron microscopy. One-week-old biofilms grown anaerobically at 37°C were exposed to each of five solutions for one minute (twice daily for seven days): Listerine Total care and Paroex Gum mouthrinses, 0.12% chlorhexidine, 0.001% D-enantiomeric peptide DJK-5, and sterile water. The dynamic variation of the biovolume of the biofilms and the percentage of dead bacteria were monitored and analyzed using confocal laser scanning microscopy.

RESULTS

All restorative materials had similar surface roughness with intact biofilm attachment. The percentage of dead bacteria and biovolume of biofilms treated by each oral rinse solution remained constant between days 1 and 7, with no statistically significant difference. DJK-5 showed the highest percentage of dead bacteria (up to 75.7%; cf. ∼20-40% for other mouthrinses) of all solutions tested within 7 days.

CONCLUSIONS

DJK-5 outperformed conventional mouthrinses in killing bacteria in oral multispecies biofilms grown on dental restorative materials.

CLINICAL SIGNIFICANCE

The antimicrobial peptide DJK-5 is effective against oral biofilms and serves as a promising candidate for the development of future mouthrinses to improve long-term oral hygiene.

Epigallocatechin-3-gallate/mineralization precursors co-delivery hollow mesoporous nanosystem for synergistic manipulation of dentin exposure

As a global public health focus, oral health plays a vital role in facilitating overall health. Defected teeth characterized by exposure of dentin generally increase the risk of aggravating oral diseases. The exposed dentinal tubules provide channels for irritants and bacterial invasion, leading to dentin hypersensitivity and even pulp inflammation. Cariogenic bacterial adhesion and biofilm formation on dentin are responsible for tooth demineralization and caries. It remains a clinical challenge to achieve the integration of tubule occlusion, collagen mineralization, and antibiofilm functions for managing exposed dentin. To address this issue, an epigallocatechin-3-gallate (EGCG) and poly(allylamine)-stabilized amorphous calcium phosphate (PAH-ACP) co-delivery hollow mesoporous silica (HMS) nanosystem (E/PA@HMS) was herein developed. The application of E/PA@HMS effectively occluded the dentinal tubules with acid- and abrasion-resistant stability and inhibited the biofilm formation of Streptococcus mutans. Intrafibrillar mineralization of collagen fibrils and remineralization of demineralized dentin were induced by E/PA@HMS. The odontogenic differentiation and mineralization of dental pulp cells with high biocompatibility were also promoted. Animal experiments showed that E/PA@HMS durably sealed the tubules and inhibited biofilm growth up to 14 days. Thus, the development of the E/PA@HMS nanosystem provides promising benefits for protecting exposed dentin through the coordinated manipulation of dentin caries and hypersensitivity.

New Technological Approaches for Dental Caries Treatment: From Liquid Crystalline Systems to Nanocarriers

Dental caries is the most common oral disease, with high prevalence rates in adolescents and low-income and lower-middle-income countries. This disease originates from acid production by bacteria, leading to demineralization of the dental enamel and the formation of cavities. The treatment of caries remains a global challenge and the development of effective drug delivery systems is a potential strategy. In this context, different drug delivery systems have been investigated to remove oral biofilms and remineralize dental enamel. For a successful application of these systems, it is necessary that they remain adhered to the surfaces of the teeth to allow enough time for the removal of biofilms and enamel remineralization, thus, the use of mucoadhesive systems is highly encouraged. Among the systems used for this purpose, liquid crystalline systems, polymer-based nanoparticles, lipid-based nanoparticles, and inorganic nanoparticles have demonstrated great potential for preventing and treating dental caries through their own antimicrobial and remineralization properties or through delivering drugs. Therefore, the present review addresses the main drug delivery systems investigated in the treatment and prevention of dental caries.

pH-activated antibiofilm strategies for controlling dental caries

Dental biofilms are highly assembled microbial communities surrounded by an extracellular matrix, which protects the resident microbes. The microbes, including commensal bacteria and opportunistic pathogens, coexist with each other to maintain relative balance under healthy conditions. However, under hostile conditions such as sugar intake and poor oral care, biofilms can generate excessive acids. Prolonged low pH in biofilm increases proportions of acidogenic and aciduric microbes, which breaks the ecological equilibrium and finally causes dental caries. Given the complexity of oral microenvironment, controlling the acidic biofilms using antimicrobials that are activated at low pH could be a desirable approach to control dental caries. Therefore, recent researches have focused on designing novel kinds of pH-activated strategies, including pH-responsive antimicrobial agents and pH-sensitive drug delivery systems. These agents exert antibacterial properties only under low pH conditions, so they are able to disrupt acidic biofilms without breaking the neutral microenvironment and biodiversity in the mouth. The mechanisms of low pH activation are mainly based on protonation and deprotonation reactions, acids labile linkages, and H⁺-triggered reactive oxygen species production. This review summarized pH-activated antibiofilm strategies to control dental caries, concentrating on their effect, mechanisms of action, and biocompatibility, as well as the limitation of current research and the prospects for future study.

Enhancing adhesive-dentin interface stability of primary teeth: From ethanol wet-bonding to plant-derived polyphenol application

OBJECTIVES

To investigate whether the adhesive-dentin interface stability of primary teeth would be enhanced by epigallocatechin-3-gallate (EGCG) with ethanol wet-bonding.

METHODS

Non-caries primary molars were sliced to achieve a flat dentin surface and etched then randomly distributed into five groups in accordance with different treatments: group 1, no treatment; group 2, applying absolute ethanol wet-bonding for 60 s; groups 3-5, applying 0.1%, 0.5%, and 1% (w/v) EGCG-incorporating ethanol wet-bonding (0.1%, 0.5%, and 1% EGCG) for 60 s. Singlebond universal adhesive was then applied followed by resin composite construction. Microtensile bond strength, fracture mode, and nanoleakage at adhesive-dentin interface were evaluated after 24 h of water storage or 10,000 times of thermocycling. Zymography of hybrid layer, biofilm formation of Streptococcus mutans by CLSM, FESEM, and MTT test, and cytotoxicity by CCK-8 assay were respectively assessed.

RESULTS

Irrespective of thermocycling, the dentin bond strength was preserved with reduced nanoleakage in the 0.5% and 1% EGCG groups. Furthermore, the activity of endogenous proteases and the growth of Streptococcus mutans biofilm were inhibited after treatment with 0.5% and 1% EGCG/ethanol solutions (groups 4 and 5). CCK-8 results of the 0.1% and 0.5% EGCG groups showed acceptable biocompatibility.

CONCLUSIONS

Treatment by EGCG/ethanol solutions effectively enhanced the bond stability of primary teeth at the adhesive-dentin interface.

CLINICAL SIGNIFICANCE

Synergistic application of EGCG and ethanol wet-bonding suggesting a promising strategy to improve dentin bonding durability with bacterial biofilm inhibition, thus increasing resin-based restorations' service life in primary dentition.