Potential apply of hydrogel-carried chlorhexidine and metronidazole in root canal disinfection

Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases

Oral health is the basis of human health, and almost everyone has been affected by oral diseases. Among them, endodontic disease is one of the most common oral diseases. Limited by the characteristics of oral biomaterials, clinical methods for endodontic disease treatment still face large challenges in terms of reliability and stability. The hydrogel is a kind of good biomaterial with an adjustable 3D network structure, excellent mechanical properties, and biocompatibility and is widely used in the basic and clinical research of endodontic disease. This Review discusses the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment. The emphasis is on the working principles and therapeutic effects of treating different diseases with functional hydrogels. Finally, the challenges and opportunities of hydrogels in oral clinical applications are discussed and proposed. Some viewpoints about the possible development direction of functional hydrogels for oral health in the future are also put forward. Through systematic analysis and conclusion of the recent advances in functional hydrogels for dental hard tissue and endodontic disease treatment, this Review may provide significant guidance and inspiration for oral disease and health in the future.

Nanoarchitectonics-Based Materials as a Promising Strategy in the Treatment of Endodontic Infections

Endodontic infections arise from the interactive activities of microbial communities colonizing in the intricate root canal system. The present study aims to update the latest knowledge of nanomaterials, their antimicrobial mechanisms, and their applications in endodontics. A detailed literature review of the current knowledge of nanomaterials used in endodontic applications was performed using the PubMed database. Antimicrobial nanomaterials with a small size, large specific surface area, and high chemical activity are introduced to act as irrigants, photosensitizer delivery systems, and medicaments, or to modify sealers. The application of nanomaterials in the endodontic field could enhance antimicrobial efficiency, increase dentin tubule penetration, and improve treatment outcomes. This study supports the potential of nanomaterials as a promising strategy in treating endodontic infections.

Recent advancements in hydrogels as novel tissue engineering scaffolds for dental pulp regeneration

Although conventional root canal treatment offers an effective therapeutic solution, it negatively affects the viability of the affected tooth. In recent years, pulp regeneration technology has emerged as a novel method for treating irreversible pulpitis due to its ability to maintain tooth vitality. The successful implementation of this technique depends on scaffolds and transplantation of exogenous stem cells or recruitment of endogenous stem cells. Accordingly, the three-dimensional structure and viscoelastic characteristics of hydrogel scaffolds, which parallel those of the extracellular matrix, have generated considerable interest. Furthermore, hydrogels support the controlled release of regenerative drugs and to load a wide variety of bioactive molecules. By integrating antibacterial agents into the hydrogel matrix and stimulating an immune response, root canal disinfection can be significantly improved and the rate of pulp regeneration can be accelerated. This review aims to provide an overview of the clinical applications of hydrogels that have been reported in the last 5 years, and offer a comprehensive summary of the different approaches that have been utilized for the optimization of hydrogel scaffolds for pulp regeneration. Advancements and challenges in pulp regeneration using hydrogels treating aged teeth are discussed.

Factorial design of in situ gelling two-compartment systems containing chlorhexidine for the treatment of periodontitis

Periodontitis is one of the most widespread bacterial infectious oral diseases that affects a significant percentage of the population worldwide. Different bacterial strains are responsible for the chronic inflammation and subgingival plaque that could be effectively treated with prolonged exposure to therapeutic levels of antibiotics and antiseptics in the periodontal pockets. Medicated in situ gels of chlorhexidine (CHX), for extended drug release and long-lasting antiseptic effect in the targeted cavities, were prepared in a two-compartment system. One compartment was loaded with sodium alginate solution while other was filled with CHX and calcium solution. The mixing of the solutions during the application resulted in gelation. Two 33 full factorial designs were applied in this study in order to optimize the gel formulation. Initially, the effects of concentration of gelling agent, crosslinker, and pH of the system on the dependent variables such as gel formation and structure characteristics were investigated. Then, the concentration of the crosslinker was optimized. Afterwards, the effect of gelling agent, loading of the drug, and pH of the gel system were correlated with the gel characteristics through another factorial design. Optimized formulations were tested for mucoadhesion, in vitro drug release, and microbiological investigation. Based on the results of the factorial design, mucoadhesiveness, antimicrobial investigation, and drug release, a 4 % alginate composition can be considered optimal. Overall, the optimized in situ periodontal gel was found to be effective with prolonged retention time and desirable outcomes.

Bioactive Endodontic Hydrogels: From Parameters to Personalized Medicine

Regenerative endodontic procedures (REPs) aim at recreating dental pulp tissue using biomaterials such as hydrogels. Their bioactivity is mostly related to the nature of biomolecules or chemical compounds that compose the endodontic hydrogel. However, many other parameters, such as hydrogel concentration, bioactive molecules solubility, and apex size, were reported to influence the reciprocal host-biomaterial relationship and hydrogel behavior. The lack of knowledge regarding these various parameters, which should be considered, leads to the inability to predict the clinical outcome and suggests that the biological activity of endodontic hydrogel is impossible to anticipate and could hinder the bench-to-bedside transition. We describe, in this review, that most of these parameters could be identified, described, and studied. A second part of the review lists some challenges and perspectives, including development of future mathematical models that are able to explain, and eventually predict, the bioactivity of endodontic hydrogel used in a clinical setting.

Characterization, Antimicrobial Activity, and Antioxidant Efficacy of a Pomegranate Peel Solution Against Persistent Root Canal Pathogens

BACKGROUND

The limitations of dental irrigation solutions reinforce the need to explore novel bioactive compounds that are safer and biodegradable. This study aimed to prepare a 10% pomegranate peel solution (Punica granatum extract - PGE) and evaluate its antimicrobial and antioxidant effects for root canal treatment.

METHODS

Lyophilized extracts (1g/10 mL) from pomegranate peels were prepared, and the punicalagin content was assessed by ultra-performance liquid chromatography using pure punicalagin (standard). The antimicrobial activity was tested against common persistent root canal pathogens by the agar diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal/fungicide concentration (MCB/MFC). The antioxidant activity (%AA) was assessed by the DPPH radical scavenging method. Data were analyzed by ANOVA and Tukey's test (α = 0.05).

RESULTS

The total phenolic content of the PGEextract was 6.55 µg/mL. Differences were found among the inhibition zone of PGE (23.32 ± 3.65), 1% NaOCl (30.76 ± 4.73), and 50% ethanol (without inhibition) (p < 0.05). The MIC values of PGE ranged between 6.25 and 75 mg/ml, and PGE was effective against the tested pathogens. PGE had antioxidant potential (IC50 = 3.52 µg/mL); however, the mean values were inferior to that of the quercetin (positive control) (IC50 = 0.95 µg/mL). The DPPH scavenging effect (%AA) of PGE (70.98 ± 2.3) had no difference from the positive control (72.94 ± 2.1) (p = 0.253).

CONCLUSION

The PGE extract was successfully biosynthesized and exhibited antimicrobial and antioxidant activity, suggesting its potential use as an adjuvant therapy during root canal treatment.

Unraveling the New Perspectives on Antimicrobial Hydrogels: State-of-the-Art and Translational Applications

The growing impact of infections and the rapid emergence of antibiotic resistance represent a public health concern worldwide. The exponential development in the field of biomaterials and its multiple applications can offer a solution to the problems that derive from these situations. In this sense, antimicrobial hydrogels represent a promising opportunity with multiple translational expectations in the medical management of infectious diseases due to their unique physicochemical and biological properties as well as for drug delivery in specific areas. Hydrogels are three-dimensional cross-linked networks of hydrophilic polymers that can absorb and retain large amounts of water or biological fluids. Moreover, antimicrobial hydrogels (AMH) present good biocompatibility, low toxicity, availability, viscoelasticity, biodegradability, and antimicrobial properties. In the present review, we collect and discuss the most promising strategies in the development of AMH, which are divided into hydrogels with inherent antimicrobial activity and antimicrobial agent-loaded hydrogels based on their composition. Then, we present an overview of the main translational applications: wound healing, tissue engineering and regeneration, drug delivery systems, contact lenses, 3D printing, biosensing, and water purification.

Advances on Hydrogels for Oral Science Research

Hydrogels are biocompatible polymer systems, which have become a hotspot in biomedical research. As hydrogels mimic the structure of natural extracellular matrices, they are considered as good scaffold materials in the tissue engineering area for repairing dental pulp and periodontal damages. Combined with different kinds of stem cells and growth factors, various hydrogel complexes have played an optimistic role in endodontic and periodontal tissue engineering studies. Further, hydrogels exhibit biological effects in response to external stimuli, which results in hydrogels having a promising application in local drug delivery. This review summarized the advances of hydrogels in oral science research, in the hopes of providing a reference for future applications.