Local Drug Delivery Systems for Vital Pulp Therapy: A New Hope

Efficacy of calcium hydroxide-loaded poly(lactic-co-glycolic acid) biodegradable nanoparticles as an intracanal medicament against endodontopathogenic microorganisms in a multi-species biofilm model

This study aimed to evaluate the antimicrobial activity of calcium hydroxide-loaded poly(lactic-co-glycolic acid) nanoparticles (CH-loaded PLGA NPs) on multi-species biofilms. Human root blocks were prepared (n = 40), and multi-species suspensions of Candida albicans, Enterococcus faecalis and Streptococcus gordonii were incubated within the root canals for 21 days. Canals (n = 10/group) were then medicated with saline solution (negative control), chlorhexidine (positive control), calcium hydroxide and CH-loaded PLGA NPs for 7 days. Samples taken from the 0.1 mm root canal dentin were collected, and cell growth was detected by culture on BHI agar. The viable cell count of the Ca(OH)2, chlorhexidine gel and CH-loaded PLGA NPs group was significantly lower than the normal saline group (p < 0.001). CH-loaded PLGA NPs demonstrated a significant lower viable cell than Ca(OH)2 (p < 0.001); it has potential as a medicament for endodontic therapy.

The Role of Growth Factor Delivery Systems on Cellular Activities of Dental Stem Cells: A Systematic Review (Part II)

OBJECTIVE

The current systematic review aims to provide the available ex vivo evidence evaluating the biological interactions of dental stem cells (DSCs) and growth factor delivery systems.

METHODS

Following the Preferred Reporting Items for a Systematic Reviews and Meta-Analyses (PRISMA) guidelines, systematic search was conducted in the electronic databases (PubMed/Medline, Scopus, Web of Science, and Google Scholar) up to January 2022. Studies evaluating the biological interactions of DSCs and growth factor delivery systems were included. The outcome measures were cell cytocompatibility, mineralization, and differentiation.

RESULTS

Sixteen studies were selected for the qualitative synthesis. The following growth factor delivery systems exhibit adequate cytocompatibility, enhanced mineralization, and osteo/odontoblast differentiation potential of DSCs: 1) Fibroblast growth factor (FGF-2)-loaded-microsphere and silk fibroin, 2) Bone morphogenic protein-2 (BMP-2)-loaded-microsphere and mesoporous calcium silicate scaffold, 3) Transforming growth factor Beta 1 (TGF-ß1)-loaded-microsphere, glass ionomer cement (GIC), Bio-GIC and liposome, 4) TGF-ß1-loaded-nanoparticles/scaffold, 5) Vascular endothelial growth factor (VEGF)-loaded-fiber and hydrogel, 6) TGF-ß1/VEGF-loaded-nanocrystalline calcium sulfate/hydroxyapatite/calcium sulfate, 7) Epidermal growth factor-loaded- nanosphere, 8) Stem cell factor/DSCs-loaded-hydrogel and Silk fibroin, 9) VEGF/BMP-2/DSCs-loaded-Three-dimensional matrix, 10) VEGF/DSCs-loaded-microsphere/hydrogel, and 11) BMP-2/DSCs and VEGF/DSCs-loaded-Collagen matrices. The included delivery systems showed viability, except for Bio-GIC on day 3. The choice of specific growth factors and delivery systems (i.e., BMP-2-loaded-microsphere and VEGF-loaded-hydrogel) resulted in a greater gene expression.

CONCLUSIONS

This study, with low-level evidence obtained from ex vivo studies, suggests that growth factor delivery systems induce cell proliferation, mineralization, and differentiation toward a therapeutic potential in regenerative endodontics.

Beyond Tradition: Non-surgical Endodontics and Vital Pulp Therapy as a Dynamic Combination

Symptomatic irreversible pulpitis and apical periodontitis in mature permanent teeth present challenges in their management. Traditional treatment approaches, such as root canal therapy or tooth extraction, may compromise tooth structure and oral function. This review article explores the combination of non-surgical endodontic treatment and vital pulp therapy as an alternative approach for these conditions. The purpose is to examine this combined approach's effectiveness, benefits, challenges, and limitations. The objectives include reviewing the literature, evaluating clinical outcomes, discussing potential benefits, and providing recommendations for clinical practice. The combination approach aims to preserve tooth structure, promote healing, and reduce postoperative complications. The article discusses the rationale for combining the two techniques, presents evidence supporting their efficacy, and outlines the techniques and protocols involved. Clinical outcomes, case studies, potential challenges, and comparative analysis with traditional approaches are also explored. Future directions and research recommendations highlight areas for further investigation, innovations, and the development of clinical guidelines. In conclusion, the combination of non-surgical endodontic treatment and vital pulp therapy offers a valuable strategy for managing mature permanent mandibular molars with symptomatic irreversible pulpitis and apical periodontitis. Further research and advancements are needed to refine the treatment protocol and expand the evidence base, and clinicians should stay updated to provide optimal care and improve patient outcomes.

Healing of Large Endodontic Lesions Using Long-Term Application of a New Combination of Triple Antibiotics: A Series of Cases

Apical periodontitis (AP) is defined as an inflammatory and destructive reaction of periapical tissues and a consequence of bacterial invasion to the dental pulp and root canal system. To avoid possible complications and undesirable repercussions of the surgical treatment of large AP, more conservative non-surgical approaches are endorsed. In the presented hopeless cases, a newly introduced modified combination of triple antibiotics, that is Penicillin G, metronidazole, and ciprofloxacin (PMC), was used as a long-term intracanal medication in the non-surgical endodontic retreatments of large AP. In the course of 10-month to 3-year follow-up, the large periapical lesions completely disappeared, and thorough bone healing was evident. Additionally, complete functionality of the involved teeth as well as other favourable treatment outcomes of the addressed cases showed that the long-term use of PMC, as a modified combination of antibiotics, in non-surgical endodontic retreatments may successfully resolve large AP. However, further investigations and well-designed controlled clinical trials are recommended.

Healing of large endodontic lesions using a new combination of triple antibiotics: A case report

In the case report presented, three cases of large endodontic lesions, which were the consequences of endodontic treatment failure, were studied. In all cases, a novel combination of triple antibiotics was used to successfully manage and heal the lesions, showing the promising potential of the antibiotic combination in resolving pathosis.

Challenging the Misnomer of Irreversible Pulpitis and Deliberating the Urgent Need for Reclassification of Pulpal Diseases Based on the Efficacy of Vital Pulp Therapies: An Overview of Systematic Reviews

Over recent decades, the definition of irreversible pulpitis (IP), as an irrevocable condition of a compromised dental pulp tissue, has forced clinicians towards invasive root canal treatments. However, the current best evidence challenges the alignment between clinical symptoms and the perceived irreversibility of a negotiated dental pulp tissue. In the above-mentioned context, vital pulp therapy (VPT) has emerged as a revolutionary and transformative approach; introducing minimally invasive techniques to sustain pulp vitality in cases of IP. The present paper aimed to rigorously examine the corresponding published systematic reviews to explore the diverse spectrum of VPT modalities and their outcomes in managing IP cases. Besides, the current review seems to have asserted the need to discard the conventional terminology of irreversible pulpitis, based on the effectiveness of VPTs in the achievement of pulp tissue healing within cases clinically diagnosed as IP.

Pulp Therapy of Primary Dentition; its Relevance despite Insufficient Histological Evidence: A Review

Pulp treatment in primary dentition is generally divided into vital and non-vital pulp therapies and assists in the preservation of pulpally involved primary teeth in the dental arch until the affected tooth naturally exfoliates. The success of pulp therapies depends on several factors; e.g. proper case selection, accurate diagnosis and good coronal seal. To date, studies on the success and failure rates of pulp treatments are based on clinical signs and symptoms, radiographic findings and histological analysis. However, the clinical and radiographic evidence may not completely portray the true status of the dental pulp. Histological evidence remains the gold standard in the assessment of pulp condition, whether it is in a healthy or adverse state. The aims of the current research were to summarise the treatment outcomes of pulp therapy in primary dentition based on clinical, radiographic and histological criteria, and to support its relevance in the presence of limited histological evidence to measure authentic treatment success. An electronic database search of dental literature from 1990 to 2022 was carried out using the MEDLINE, i.e. PubMed, database. Current dental literature showed that the success rates of primary tooth pulp therapy are high. The obtained results were based largely on clinical and radiographic studies with narrow histological investigations to assess the treatment outcome(s) of pulp therapy in primary dentition. Despite the scarcity of histological evidence, pulp therapies in primary teeth are still practical due to their statistically empirical success compared to their failure. Consequently, pulp therapy of primary dentition is still relevant, and should continue to be indicated as an important treatment option.

Anti-Inflammatory and Mineralization Effects of an ASP/PLGA-ASP/ACP/PLLA-PLGA Composite Membrane as a Dental Pulp Capping Agent

Dental pulp is essential for the development and long-term preservation of teeth. Dental trauma and caries often lead to pulp inflammation. Vital pulp therapy using dental pulp-capping materials is an approach to preserving the vitality of injured dental pulp. Most pulp-capping materials used in clinics have good biocompatibility to promote mineralization, but their anti-inflammatory effect is weak. Therefore, the failure rate will increase when dental pulp inflammation is severe. The present study developed an amorphous calcium phosphate/poly (L-lactic acid)-poly (lactic-co-glycolic acid) membrane compounded with aspirin (hereafter known as ASP/PLGA-ASP/ACP/PLLA-PLGA). The composite membrane, used as a pulp-capping material, effectively achieved the rapid release of high concentrations of the anti-inflammatory drug aspirin during the early stages as well as the long-term release of low concentrations of aspirin and calcium/phosphorus ions during the later stages, which could repair inflamed dental pulp and promote mineralization. Meanwhile, the composite membrane promoted the proliferation of inflamed dental pulp stem cells, downregulated the expression of inflammatory markers, upregulated the expression of mineralization-related markers, and induced the formation of stronger reparative dentin in the rat pulpitis model. These findings indicate that this material may be suitable for use as a pulp-capping material in clinical applications.

Evaluating the Effect of Tideglusib-Loaded Bioactive Glass Nanoparticles as a Potential Dentine Regenerative Material

Dental pulp treatment is the least intrusive procedure currently available for preserving the vitality of the pulp. Several studies are underway to improve the bioactivity of pulp capping materials. Tideglusib isa potent anti-inflammatory, antioxidant, and a regenerative drug developed against Alzheimer’s disease and has been shown to be effective in the treatment of dental cavities. However, its bioactive properties encapsulated within the nanoparticles as a component of pulp capping material are largely unknown. In this study, tideglusib-loaded bioactive glass nanoparticles were synthesized (tideglusib-BgNPs) and mixed at various concentrations into the calcium silicate cement to testits physiomechanical and bioactivitiescompared with biodentine (control). The calcium silicate cement with 10wgt% tideglusib-BgNPs showed comparable physiomechanical properties to that of biodentine. Additionally, the assessment of cytotoxicity and bioactivity (cell proliferation, wound healing, and cell migration assays) showed increased bioactivity in terms of better wound healing, increased proliferation, and better migration of human dental pulp stem cells than biodentine. These findings suggest new opportunities to use tideglusib-BgNPs in pulp therapy.

Management of External Inflammatory Root Resorption following Tooth Autotransplantation Using a Modified Combination of Triple Antibiotics

External inflammatory root resorption (EIRR) is one of the most undesirable potential repercussions of various types of trauma and traumatic injuries to the tooth and its structure. This detrimental phenomenon may lead to severe complications, the consequent destruction of dental tissues, and eventual tooth loss. In the presented case, following the autogenous transplantation of tooth #17 as the host-tissue replacement for tooth #18, signs of EIRR were radiographically detected after 6 months. However, the thorough preparation of root canals, which involves complete cleaning and shaping, in addition to the application of a modified combination of triple antibiotics, consisting of penicillin G, metronidazole, and ciprofloxacin (PMC), managed to arrest EIRR. Moreover, the obturation of root canals using calcium-enriched mixture (CEM) cement as the endodontic biomaterial as well as the proper management of EIRR resulted in the healing of periradicular pathosis, abatement of clinical symptoms, and finally refunctionalisation of the tooth during a follow-up period of 2 years. It seems that the appropriate disinfection of the root canal system using PMC next to the prevention of microbial recontamination using CEM cement can perfectly manage EIRR.

Human Treated Dentin Matrix Hydrogel as a Drug Delivery Scaffold for Regenerative Endodontics

Introduction

The objective of the current study was to develop a human treated dentin matrix (hTDM) hydrogel for use as a scaffold to allow the controlled release of an antimicrobial agent for regenerative endodontics.

Materials and Methods

Human extracted teeth were treated via chemical demineralization using ethylene diamine tetra-acetic acid solution to produce hTDM powder. Fourier transform infrared spectroscopy (FTIR) was conducted to determine the functional groups of hTDM, scanning electron microscopy (SEM) was used to define the morphology/particle size of hTDM, and energy dispersive X-ray analysis was performed to identify the superficial apatite groups. Prepared hTDM powder was added to the amoxicillin-clavulanate mixture with a mass ratio of 1:1. Then, the combination was dripped into a 5% (w/v) calcium chloride solution. Antibiotic release profiles were evaluated for 14 days via high performance liquid chromatography (HPLC). Hydrogel degradation properties were studied for 14 days using 10 mL of phosphate buffered saline (PBS). Encapsulation efficiency was determined by HPLC, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of amoxicillin-clavulanate were determined against Enterococcus faecalis (E. faecalis). The antibacterial activity of amoxicillin-clavulanate against E. faecalis was investigated for 14 days via agar diffusion test. Statistical analysis was performed with the Shapiro-Wilk test (P=0.05).

Results

hTDM showed statistically a significant difference for percentage weight change (P=0.1). The encapsulation efficiencies for hTDM hydrogel with antibiotic and hydrogel with antibiotic was 96.08%±0.02 and 94.62%±0.11, respectively. MIC and MBC values of amoxicillin-clavulanate against E. faecalis were 2.4 µg/mL and 9.6 µg/mL, respectively. The antibacterial activity of antibiotic loaded hTDM hydrogels was significantly greater than loaded hydrogels alone by 31% after 4 days and 100% at 14 days, respectively (P≤0.001).

Conclusions

This in vitro study showed antibiotic-loaded injectable hTDM hydrogel could be an alternative system to transfer antibiotic-based intracanal medicaments for use in regenerative endodontics.