Tomographic evaluation of direct pulp capping using a novel injectable treated dentin matrix hydrogel: a 2-year randomized controlled clinical trial

Comparison of two CBCT analysis techniques with conventional periapical radiographs in assessment of tertiary dentin after indirect pulp capping in young permanent teeth

BACKGROUND AND AIM

To compare two cone beam computed tomography (CBCT) analysis techniques for measuring tertiary dentin (TD) volume, density, and root length increase, after indirect pulp therapy (IPT) in young permanent teeth with conventional periapical radiographs.

DESIGN

Comparative study design: Sixty-nine CBCT scans were taken initially (T1) and after 1 year (T2) of IPT. New CBCT analysis technique A, standardization, segmentation, and registration of T1 and T2 scans were performed using ITK-SNAP and 3D Slicer CMF to measure TD volume (mm3), density (gray-level intensity), and root length increase (mm). In the traditional CBCT analysis technique B, analyses were conducted using the In-Vivo software to calculate TD thickness (mm), radiodensity (HU%), and root length increase (mm). Paired t-test and the intraclass correlation coefficient were calculated to compare and assess the reliability of all techniques.

RESULTS

No significant difference between the two techniques existed in the measurement of TD mineral density (Mean [SD]:A = 22.4 [15.4]; B = 24.4 [15.4]; p = .47). Technique A resulted in significantly higher root length increase values (Mean [SD]: A = 1.3 [0.6]; B = 1.1 [0.5]; p = .03). The two techniques showed acceptable reliability levels (0.76-0.99).

CONCLUSION

CBCT analysis techniques yielded similar findings for mineral density. The new CBCT volumetric analysis technique, although more laborious, produced higher values for root length increase, and allowed for measurement of dentin volume.

Electrical Stimulations Generated by P(VDF-TrFE) Films Enhance Adhesion Forces and Odontogenic Differentiation of Dental Pulp Stem Cells (DPSCs)

Biophysical and biochemical cues of biomaterials can regulate cell behaviors. Dental pulp stem cells (DPSCs) in pulp tissues can differentiate to odontoblast-like cells and secrete reparative dentin to form a barrier to protect the underlying pulp tissues and enable complete pulp healing. Promotion of the odontogenic differentiation of DPSCs is essential for dentin regeneration. The effects of the surface potentials of biomaterials on the adhesion and odontogenic differentiation of DPSCs remain unclear. Here, poly(vinylidene fluoride-trifluoro ethylene) (P(VDF-TrFE)) films with different surface potentials were prepared by the spin-coating technique and the contact poling method. The cytoskeletal organization of DPSCs grown on P(VDF-TrFE) films was studied by immunofluorescence staining. Using atomic force microscopy (AFM), the lateral detachment forces of DPSCs from P(VDF-TrFE) films were quantified. The effects of electrical stimulation generated from P(VDF-TrFE) films on odontogenic differentiation of DPSCs were evaluated in vitro and in vivo. The unpolarized, positively polarized, and negatively polarized films had surface potentials of -52.9, +902.4, and -502.2 mV, respectively. DPSCs on both negatively and positively polarized P(VDF-TrFE) films had larger cell areas and length-to-width ratios than those on the unpolarized films (P < 0.05). During the detachment of DPSCs from P(VDF-TrFE) films, the average magnitudes of the maximum detachment forces were 29.4, 72.1, and 53.9 nN for unpolarized, positively polarized, and negatively polarized groups, respectively (P < 0.05). The polarized films enhanced the mineralization activities and increased the expression levels of the odontogenic-related proteins of DPSCs compared to the unpolarized films (P < 0.05). The extracellular signal-regulated kinase (ERK) signaling pathway was involved in the odontogenic differentiation of DPSCs as induced by surface charge. In vivo, the polarized P(VDF-TrFE) films enhanced adhesion of DPSCs and promoted the odontogenic differentiation of DPSCs by electrical stimulation, demonstrating a potential application of electroactive biomaterials for reparative dentin formation in direct pulp capping.

Bioactive injectable mucoadhesive thermosensitive natural polymeric hydrogels for oral bone and periodontal regeneration

Periodontitis is an inflammation-related condition, caused by an infectious microbiome and host defense that causes damage to periodontium. The natural processes of the mouth, like saliva production and eating, significantly diminish therapeutic medication residency in the region of periodontal disease. Furthermore, the complexity and diversity of pathological mechanisms make successful periodontitis treatment challenging. As a result, developing enhanced local drug delivery technologies and logical therapy procedures provides the foundation for effective periodontitis treatment. Being biocompatible, biodegradable, and easily administered to the periodontal tissues, hydrogels have sparked substantial an intense curiosity in the discipline of periodontal therapy. The primary objective of hydrogel research has changed in recent years to intelligent thermosensitive hydrogels, that involve local adjustable sol-gel transformations and regulate medication release in reaction to temperature, we present a thorough introduction to the creation and efficient construction of new intelligent thermosensitive hydrogels for periodontal regeneration. We also address cutting-edge smart hydrogel treatment options based on periodontitis pathophysiology. Furthermore, the problems and prospective study objectives are reviewed, with a focus on establishing effective hydrogel delivery methods and prospective clinical applications.

Antimicrobial Peptide- and Dentin Matrix-Functionalized Hydrogel for Vital Pulp Therapy via Synergistic Bacteriostasis, Immunomodulation, and Dentinogenesis

The preservation of vital pulps is crucial for maintaining the physiological functions of teeth; however, vital pulp therapy (VPT) of pulpitis teeth remains a substantial challenge due to uncontrolled infection, excessive inflammation, and limited regenerative potential. Current pulp capping agents have restricted effects in the infectious and inflammatory microenvironment. To address this, a multifunctional hydrogel (TGH/DM) with antibacterial, immunomodulatory, and mineralization-promoting effects is designed. The antimicrobial peptide (AMP) and demineralized dentin matrix are incorporated into the hydrogel, achieving sustainable delivery of AMP and a cocktail of growth factors. In vitro results show that TGH/DM could kill endodontic microbiota, ameliorate inflammatory responses of human dental pulp stem cells (hDPSCs), and prompt odontogenic differentiation of inflammatory hDPSCs via activation of peroxisome proliferator-activated receptor gamma. In vivo results suggest that TGH/DM is capable of inducing M2 phenotype transformation of macrophages in mice and fostering the regeneration of the dentin-pulp complex in inflamed pulps of beagle dogs. Overall, this study first proposes the synergistic regulation of AMP and tissue-specific extracellular matrix for the treatment of pulpitis, and the advanced hydrogel provides a facile and effective way for VPT.

An animal study on the effectiveness of platelet-rich plasma as a direct pulp capping agent

Direct pulp capping (DPC) is a conservative approach for preserving tooth vitality without requiring more invasive procedures by enhancing pulp healing and mineralized tissue barrier formation. We investigated the effectiveness of Platelet Rich Plasma (PRP) vs. Mineral Trioxide Aggregate (MTA) as a DPC agent. Forty-two teeth from three mongrel dogs were divided into two equal groups. After three months, the animals were sacrificed to evaluate teeth radiographically using cone-beam computerized tomography, histopathologically, and real-time PCR for dentin sialophosphoprotein (DSPP), matrix extracellular phosphoglycoprotein (MEPE), and nestin (NES) mRNA expression. Radiographically, hard tissue formation was evident in both groups without significant differences (p = 0.440). Histopathologic findings confirmed the dentin bridge formation in both groups; however, such mineralized tissues were homogenous without cellular inclusions in the PRP group, while was osteodentin type in the MTA group. There was no significant difference in dentin bridge thickness between the PRP-capped and MTA-capped teeth (p = 0.732). The PRP group had significantly higher DSPP, MEPE, and NES mRNA gene expression than the MTA group (p < 0.05). In conclusion, PRP enables mineralized tissue formation following DPC similar to MTA, and could generate better cellular dentinogenic responses and restore dentin with homogenous architecture than MTA, making PRP a promising alternative DPC agent.

Histological evaluation of the regenerative potential of a novel photocrosslinkable gelatin-treated dentin matrix hydrogel in direct pulp capping: an animal study

BACKGROUND

To assess histologically the success of the pulp capping approach performed in traumatically exposed dogs' teeth using a novel injectable gelatin-treated dentin matrix light cured hydrogel (LCG-TDM) compared with LCG, MTA and TheraCal LC.

METHODS

Sixty-four dogs' teeth were divided into two groups (each including 32 teeth) based on the post-treatment evaluation period: group I: 2 weeks and group II: 8 weeks. Each group was further subdivided according to the pulp capping material into four subgroups (n = 8), with subgroup A (light-cured gelatin hydrogel) as the control subgroup, subgroup B (LCG-TDM), subgroup C (TheraCal LC), and subgroup D (MTA). Pulps were mechanically exposed in the middle of the cavity floor and capped with different materials. An assessment of periapical response was performed preoperatively and at 8 weeks. After 2 and 8-week intervals, the dogs were sacrificed, and the teeth were stained with hematoxylin-eosin and graded by using a histologic scoring system. Statistical analysis was performed using the chi-square and Kruskal-Wallis tests (p = 0.05).

RESULTS

All subgroups showed mild inflammation with normal pulp tissue at 2 weeks with no significant differences between subgroups (p ≤ 0.05), except for the TheraCal LC subgroup, which exhibited moderate inflammation (62.5%). Absence of a complete calcified bridge was reported in all subgroups at 2 weeks, while at 8 weeks, the majority of samples in the LCG-TDM and MTA-Angelus subgroups showed complete dentin bridge formation and absence of inflammatory pulp response with no significant differences between them (p ≤ 0.05). However, the formed dentin in the LCG-TDM group was significantly thicker, with layers of ordered odontoblasts identified to create a homogeneous tubular structure and numerous dentinal tubule lines suggesting a favourable trend towards dentin regeneration. TheraCal LC samples revealed a reasonably thick dentin bridge with moderate inflammation (50%) and LCG showed heavily fibrous tissue infiltrates with areas of degenerated pulp with no signs of hard tissue formation.

CONCLUSIONS

LCG-TDM, as an extracellular matrix-based material, has the potential to regenerate dentin and preserve pulp vitality, making it a viable natural alternative to silicate-based cements for healing in vivo dentin defects in direct pulp-capping procedures.

Marginal adaptation, physicochemical and rheological properties of treated dentin matrix hydrogel as a novel injectable pulp capping material for dentin regeneration

BACKGROUND

Treated dentin matrix hydrogel (TDMH) has been introduced as a novel injectable direct pulp capping material. In this regard, this study aimed to evaluate its marginal adaptation, physicochemical and rheological properties for the development of clinically feasible TDMH.

METHODS

TDMH was applied to the pulp floor of prepared Class I cavities (n = 5), marginal adaptation was assessed by SEM at 1000 X magnification to detect gap between dentin and filling material. Five syringes were filled with TDMH and placed between the compression plates of a universal testing machine to evaluate injectability and gelation time was also evaluated by test vial inverting method. The microstructures of lyophilized TDMH were observed by SEM. Moreover, TDMH discs (n = 5) were prepared and the water uptake (%) was determined based on the equilibrium swelling theory state of hydrogels. Its solubility was measured after one week by the ISO standard method. Rheological behaviours of TDMH (n = 5) were analysed with a rotational rheometer by computing their complex shear modulus G* and their associated storage modulus (G') and loss modulus (G''). Statistical analysis was performed using F test (ANOVA) with repeated measures and Post Hoc Test (p = 0.05).

RESULTS

TDMH presented an overall 92.20 ± 2.95% of continuous margins. It exhibited gelation during the first minute, and injectability mean was 66 ± 0.36%. TDMH showed a highly porous structure, and the pores were interconnected with an average diameter about 5.09 ± 3.17 μm. Swelling equilibrium gradually reached at 6 days up to 377%. The prepared hydrogels and maintained their shape after absorbing over three times their original weight of water. TDMH fulfilled the requirements of ISO 6876, demonstrating a weight loss of 1.98 ± 0.09% and linear viscoelastic behaviour with G` 479.2 ± 12.7 and G`` 230.8 ± 13.8.

CONCLUSIONS

TDMH provided good marginal adaptation, appropriate physicochemical and viscoelastic properties support its use as a novel direct pulp capping material in future clinical applications.

New Insights in Hydrogels for Periodontal Regeneration

Periodontitis is a destructive inflammatory disease characterized by microbial infection that damages the tissues supporting the tooth (alveolar bone, gingiva, periodontal ligament, and cementum), ultimately resulting in the loss of teeth. The ultimate goal of periodontal therapy is to achieve the regeneration of all of the periodontal tissues. Thus, tissue engineering approaches have been evolving from simple membranes or grafts to more complex constructs. Hydrogels are highly hydrophilic polymeric networks with the ability to simulate the natural microenvironment of cells. In particular, hydrogels offer several advantages when compared to other forms of scaffolds, such as tissue mimicry and sustained drug delivery. Moreover, hydrogels can maintain a moist environment similar to the oral cavity. Hydrogels allow for precise placement and retention of regenerative materials at the defect site, minimizing the potential for off-target effects and ensuring that the treatment is focused on the specific defect site. As a mechanism of action, the sustained release of drugs presented by hydrogels allows for control of the disease by reducing the inflammation and attracting host cells to the defect site. Several therapeutic agents, such as antibiotics, anti-inflammatory and osteogenic drugs, have been loaded into hydrogels, presenting effective benefits in periodontal health and allowing for sustained drug release. This review discusses the causes and consequences of periodontal disease, as well as the advantages and limitations of current treatments applied in clinics. The main components of hydrogels for periodontal regeneration are discussed focusing on their different characteristics, outcomes, and strategies for drug delivery. Novel methods for the fabrication of hydrogels are highlighted, and clinical studies regarding the periodontal applications of hydrogels are reviewed. Finally, limitations in current research are discussed, and potential future directions are proposed.

Photocrosslinkable gelatin-treated dentin matrix hydrogel as a novel pulp capping agent for dentin regeneration: I. synthesis, characterizations and grafting optimization

BACKGROUND

In recent years, treated dentin matrix (TDM) has been introduced as a bioactive hydrogel for dentin regeneration in DPC. However, no study has introduced TDM as a photocrosslinkable hydrogel with a natural photoinitiating system. Therefore, the present study aimed to explore the synthesis, characterizations and grafting optimization of injectable gelatin- glycidyl methacrylate (GMA)/TDM hydrogels as a novel photocrosslinkable pulp capping agent for dentin regeneration.

METHODS

G-GMA/TDM hydrogel was photocrosslinked using a new two-component photoinitiating system composed of riboflavin as a photoinitiator under visible light and glycine as a first time coinitiator with riboflavin. The grafting reaction conditions of G-GMA/TDM e.g. GMA concentration and reaction time were optimized. The kinetic parameters e.g. grafting efficiency (GE) and grafting percentage (GP%) were calculated to optimize the grafting reaction, while yield (%) was determined to monitor the formation of the hydrogel. Moreover, G-GMA/TDM hydrogels were characterized by swelling ratio, degradation degree, and cytotoxicity. The instrumental characterizations e.g. FTIR, 1H-NMR, SEM and TGA, were investigated for verifying the grafting reaction. Statistical analysis was performed using F test (ANOVA) and Post Hoc Test (P = 0.05).

RESULTS

The grafting reaction dramatically increased with an increase of both GMA concentration and reaction time. It was realized that the swelling degree and degradation rate of G-GMA/TDM hydrogels were significantly reduced by increasing the GMA concentration and prolonging the reaction time. When compared to the safe low and moderate GMA content hydrogels (0.048, 0.097 M) and shorter reaction times (6, 12, 24 h), G-GMA/TDM with high GMA contents (0.195, 0.391 M) and a prolonged reaction time (48 h) demonstrated cytotoxic effects against cells using the MTT assay. Also, the morphological surface of G-GMA/TDM freeze-dried gels was found more compacted, smooth and uniform due to the grafting process. Significant thermal stability was noticed due to the grafting reaction of G-GMA/TDM throughout the TGA results.

CONCLUSIONS

G-GMA/TDM composite hydrogel formed by the riboflavin/glycine photoinitiating system is a potential bioactive and biocompatible system for in-situ crosslinking the activated-light pulp capping agent for dentin regeneration.

Histopathological and immunohistochemical profiles of pulp tissues in immature dogs' teeth to two recently introduced pulpotomy materials

OBJECTIVE

The pulpal response to Hoffmann's Pulpine mineral (PMIN) and Pulpine NE (PNE) was compared to mineral trioxide aggregate (MTA) when used as pulpotomy materials in immature permanent teeth in dogs.

MATERIALS AND METHODS

Immature premolars were randomly divided according to the observation period into three equal groups (n = 24) (10 days, 30 days, and 90 days) then furtherly subdivided into 3 subgroups according to the material used. Histopathological analysis regarding inflammatory cell infiltration and dentin bridge (DB) formation was done. Immunohistochemical analysis was performed using osteopontin marker.

RESULTS

The results showed that after 90 days, both MTA and PMIN subgroups had 100% complete thick DB without inflammation in 87.5% of the samples, while the PNE subgroup failed to form DB in 37.5% of the samples and 50% of samples showed thin initial DB with heavy inflammation in 62.5% of the samples. There was no significant difference between MTA and PMIN, while there was a statistically significant difference between PNE and the two other subgroups in DB formation and inflammatory cell infiltration (P > 0.05). After 90 days, MTA showed the highest mean value of osteopontin positive fraction area followed by PMIN without statistically significant differences, while the least value was recorded in PNE subgroup with statistically significant difference with the remaining subgroups (P < 0.05).

CONCLUSION

PMIN is a promising alternative to MTA when used for pulpotomy.

CLINICAL RELEVANCE

Vital pulp therapy in immature teeth can be done using PMIN as an alternative to MTA.

Hydrogels for Oral Tissue Engineering: Challenges and Opportunities

Oral health is crucial to daily life, yet many people worldwide suffer from oral diseases. With the development of oral tissue engineering, there is a growing demand for dental biomaterials. Addressing oral diseases often requires a two-fold approach: fighting bacterial infections and promoting tissue growth. Hydrogels are promising tissue engineering biomaterials that show great potential for oral tissue regeneration and drug delivery. In this review, we present a classification of hydrogels commonly used in dental research, including natural and synthetic hydrogels. Furthermore, recent applications of these hydrogels in endodontic restorations, periodontal tissues, mandibular and oral soft tissue restorations, and related clinical studies are also discussed, including various antimicrobial and tissue growth promotion strategies used in the dental applications of hydrogels. While hydrogels have been increasingly studied in oral tissue engineering, there are still some challenges that need to be addressed for satisfactory clinical outcomes. This paper summarizes the current issues in the abovementioned application areas and discusses possible future developments.

Enhancing effects of immobilized chondroitin sulfate on odontogenic differentiation of dental pulp stem cells and reparative dentin formation

OBJECTIVES

Chondroitin sulfate (CS) is a major proteoglycan involved in the mineralization of the organic matrix of dentin. In this study, the roles of CS immobilized in crosslinked collagen I hydrogels (CS-Col I) on odontogenic differentiation of dental pulp stem cells (DPSCs) and reparative dentin formation were investigated.

METHODS

Different concentrations of CS were incorporated into the genipin- crosslinked Col I hydrogels (CS-0.05, CS-0.1, and CS-0.2 respectively). The influences of CS on proliferation and odontogenic differentiation of DPSCs were investigated. Finally, the effect of the functionalized hydrogel on the formation of reparative dentin was analyzed in a rat pulp capping model in vivo.

RESULTS

CS improved the proliferation of DPSCs seeded on the hydrogels (p<0.05). CS also enhanced the mineralization activities and increased the expression levels of the odontogenic related proteins of DPSCs on day 7 and day 14 (p<0.05). In vivo, CS-0.1 hydrogel induced reparative dentin formation with higher quality compared to mineral trioxide aggregate (MTA).

CONCLUSION

CS immobilized in Col I hydrogels could induce odontogenic differentiation of DPSCs in vitro and promote homogeneous mineralized barrier formation in vivo. CS-Col I hydrogel has the potential for reparative dentin formation of high quality in direct pulp capping.

Research Advances on Hydrogel-Based Materials for Tissue Regeneration and Remineralization in Tooth

Tissue regeneration and remineralization in teeth is a long-term and complex biological process, including the regeneration of pulp and periodontal tissue, and re-mineralization of dentin, cementum and enamel. Suitable materials are needed to provide cell scaffolds, drug carriers or mineralization in this environment. These materials need to regulate the unique odontogenesis process. Hydrogel-based materials are considered good scaffolds for pulp and periodontal tissue repair in the field of tissue engineering due to their inherent biocompatibility and biodegradability, slow release of drugs, simulation of extracellular matrix, and the ability to provide a mineralized template. The excellent properties of hydrogels make them particularly attractive in the research of tissue regeneration and remineralization in teeth. This paper introduces the latest progress of hydrogel-based materials in pulp and periodontal tissue regeneration and hard tissue mineralization and puts forward prospects for their future application. Overall, this review reveals the application of hydrogel-based materials in tissue regeneration and remineralization in teeth.

Biodegradation of an injectable treated dentin matrix hydrogel as a novel pulp capping agent for dentin regeneration

BACKGROUND

A novel injectable mixture termed treated dentin matrix hydrogel (TDMH) has been introduced for restoring dentin defect in DPC. However, no study evaluated its physiological biodegradation. Therefore, the present study aimed to assess scaffold homogeneity, mechanical properties and biodegradability in vitro and in vivo and the regenerated dentin induced by TDMH as a novel pulp capping agent in human permanent teeth.

METHODS

Three TDMH discs were weighted, and dry/wet ratios were calculated in four slices from each disc to evaluate homogeneity. Hydrogel discs were also analyzed in triplicate to measure the compressive strength using a universal testing machine. The in vitro degradation behavior of hydrogel in PBS at 37 °C for 2 months was also investigated by monitoring the percent weight change. Moreover, 20 intact fully erupted premolars were included for assessment of TDMH in vivo biodegradation when used as a novel injectable pulp capping agent. The capped teeth were divided into four equal groups according to extraction interval after 2-, 8-, 12- and 16-weeks, stained with hematoxylin-eosin for histological and histomorphometric evaluation. Statistical analysis was performed using F test (ANOVA) and post hoc test (p = 0.05).

RESULTS

No statistical differences among hydrogel slices were detected with (p = 0.192) according to homogeneity. TDMH compression modulus was (30.45 ± 1.11 kPa). Hydrogel retained its shape well up to 4 weeks and after 8 weeks completely degraded. Histological analysis after 16 weeks showed a significant reduction in TDMH area and a simultaneous significant increase in the new dentin area. The mean values of TDMH were 58.8% ± 5.9 and 9.8% ± 3.3 at 2 and 16 weeks, while the new dentin occupied 9.5% ± 2.8 at 2 weeks and 82.9% ± 3.8 at 16 weeks.

CONCLUSIONS

TDMH was homogenous and exhibited significant stability and almost completely recovered after excessive compression. TDMH generally maintained their bulk geometry throughout 7 weeks. The in vivo response to TDMH was characterized by extensive degradation of the hydrogel and dentin matrix particles and abundant formation of new dentin. The degradation rate of TDMH matched the rate of new dentin formation.

TRIAL REGISTRATION

PACTR201901866476410: 30/1/2019.

Biomineralization-inspired mineralized hydrogel promotes the repair and regeneration of dentin/bone hard tissue

Maxillofacial hard tissue defects caused by trauma or infection often affect craniofacial function. Taking the natural hard tissue structure as a template, constructing an engineered tissue repair module is an important scheme to realize the functional regeneration and repair of maxillofacial hard tissue. Here, inspired by the biomineralization process, we constructed a composite mineral matrix hydrogel PAA-CMC-TDM containing amorphous calcium phosphates (ACPs), polyacrylic acid (PAA), carboxymethyl chitosan (CMC) and dentin matrix (TDM). The dynamic network composed of Ca²⁺·COO^- coordination and ACPs made the hydrogel loaded with TDM, and exhibited self-repairing ability and injectability. The mechanical properties of PAA-CMC-TDM can be regulated, but the functional activity of TDM remains unaffected. Cytological studies and animal models of hard tissue defects show that the hydrogel can promote the odontogenesis or osteogenic differentiation of mesenchymal stem cells, adapt to irregular hard tissue defects, and promote in situ regeneration of defective tooth and bone tissues. In summary, this paper shows that the injectable TDM hydrogel based on biomimetic mineralization theory can induce hard tissue formation and promote dentin/bone regeneration.

Creating a Microenvironment to Give Wings to Dental Pulp Regeneration-Bioactive Scaffolds

Dental pulp and periapical diseases make patients suffer from acute pain and economic loss. Although root canal therapies, as demonstrated through evidence-based medicine, can relieve symptoms and are commonly employed by dentists, it is still difficult to fully restore a dental pulp's nutrition, sensory, and immune-regulation functions. In recent years, researchers have made significant progress in tissue engineering to regenerate dental pulp in a desired microenvironment. With breakthroughs in regenerative medicine and material science, bioactive scaffolds play a pivotal role in creating a suitable microenvironment for cell survival, proliferation, and differentiation, following dental restoration and regeneration. This article focuses on current challenges and novel perspectives about bioactive scaffolds in creating a microenvironment to promote dental pulp regeneration. We hope our readers will gain a deeper understanding and new inspiration of dental pulp regeneration through our summary.

Treated Dentin Matrix in Tissue Regeneration: Recent Advances

Tissue engineering is a new therapeutic strategy used to repair serious damage caused by trauma, a tumor or other major diseases, either for vital organs or tissues sited in the oral cavity. Scaffold materials are an indispensable part of this. As an extracellular-matrix-based bio-material, treated dentin matrixes have become promising tissue engineering scaffolds due to their unique natural structure, astonishing biological induction activity and benign bio-compatibility. Furthermore, it is important to note that besides its high bio-activity, a treated dentin matrix can also serve as a carrier and release controller for drug molecules and bio-active agents to contribute to tissue regeneration and immunomodulation processes. This paper describes the research advances of treated dentin matrixes in tissue regeneration from the aspects of its vital properties, biologically inductive abilities and application explorations. Furthermore, we present the concerning challenges of signaling mechanisms, source extension, individualized 3D printing and drug delivery system construction during our investigation into the treated dentin matrix. This paper is expected to provide a reference for further research on treated dentin matrixes in tissue regeneration and better promote the development of relevant disease treatment approaches.

The Understanding of Vital Pulp Therapy in Permanent Teeth: A New Perspective

The indications of vital pulp therapy (VPT) are expanding, which cases are suitable for VPT, and how to improve the success rate of VPT is a problem that often bothers us. The main purpose of VPT is to eliminate pulpitis by promoting the formation of reparative dentin or calcium bridge, so that it can continue to perform various physiological functions, and finally achieve the purpose of preserving pulp vitality and long-term preservation of affected teeth. Pulp capping and pulpotomy are the most common methods for VPT. The research field of VPT has attracted the attention of many scholars, who have studied it from many aspects (such as indications, material selection, operation requirements, and long-term prognosis). This article reviews the recent advances in the techniques of VPT in permanent teeth.

The Influence of New Bioactive Materials on Pulp–Dentin Complex Regeneration in the Assessment of Cone Bone Computed Tomography (CBCT) and Computed Micro-Tomography (Micro-CT) from a Present and Future Perspective—A Systematic Review

The present paper is the first article providing a systematic literature review on the visualization of tertiary dentin influenced by modern bioactive materials in CBCT and micro-CT. Six database searches of studies on tertiary dentin visualization using CBCT produced 622 records in total, and the search of the studies on tertiary dentin using micro-CT produced 502 records in total. The results were thoroughly selected considering the inclusion criteria, and five research papers using CBCT and nine research papers using micro-CT for visualization of tertiary dentin were eventually qualified for the analysis. All the non-randomized and randomized studies presented good and high levels of quality evidence, respectively. Among the bioactive materials used, the most frequently analysed were: MTA, Biodentine dentin matrix hydrogel, Pro Root MTA, and EndoSequence root repair material. The highest thickness of the tertiary dentin was achieved after the use of MTA material in both imaging techniques. The remaining parameters had different results, taking into account the CBCT and micro-CT analysis. The possibilities of the qualitative and quantitative assessment of the particular parameters of tertiary dentin using CBCT and micro-CT techniques were presented and analysed. CBCT and micro-CT analyses can be useful in the assessment of tertiary dentin formed beneath the bioactive material applied during vital pulp treatment. The research argues that the presented results differ depending on the material applied to the pulp, the study duration (4–6 weeks), difference in teeth, species (rats, human), as well as the applied technique and differences in computer software used for the analysis.

Present status and future directions: Hydraulic materials for endodontic use

BACKGROUND

Hydraulic materials are used in Endodontics due to their hydration characteristics namely the formation of calcium hydroxide when mixing with water and also because of their hydraulic properties. These materials are presented in various consistencies and delivery methods. They are composed primarily of tricalcium and dicalcium silicate, and also include a radiopacifier, additives and an aqueous or a non-aqueous vehicle. Only materials whose primary reaction is with water can be classified as hydraulic.

OBJECTIVES

Review of the classification of hydraulic materials by Camilleri and the literature pertaining to specific uses of hydraulic cements in endodontics namely intra-coronal, intra-radicular and extra-radicular. Review of the literature on the material properties linked to specific uses providing the current status of these materials after which future trends and gaps in knowledge could be identified.

METHODS

The literature was reviewed using PUBMED, and for each clinical use, the in vitro properties such as physical, chemical, biological and antimicrobial characteristics and clinical data were extracted and evaluated.

RESULTS

A large number of publications were retrieved for each clinical use and these were grouped depending on the property type being investigated.

CONCLUSIONS

The hydraulic cements have made a difference in clinical outcomes. The main shortcoming is the poor testing methodologies employed which provide very limited information and also inhibits adequate clinical translation. Furthermore, the clinical protocols need to be updated to enable the materials to be employed effectively.

Effectiveness of Direct Pulp Capping Bioactive Materials in Dentin Regeneration: A Systematic Review

Background: Regenerative endodontics aims to restore normal pulp function in necrotic and infected teeth, restoring protective functions, such as innate pulp immunity, pulp repair through mineralization, and pulp sensibility. The aim of this systematic review was to assess the dentin regeneration efficacy of direct pulp capping (DPC) biomaterials. Methods: The literature published between 2005 and 2021 was searched by using PubMed, Web of Science, Science Direct, Google Scholar, and Scopus databases. Clinical controlled trials, randomized controlled trials, and animal studies investigating DPC outcomes or comparing different capping materials after pulp exposure were included in this systematic review. Three independent authors performed the searches, and information was extracted by using a structured data format. Results: A total of forty studies (21 from humans and 19 from animals) were included in this systemic review. Histological examinations showed complete/partial/incomplete dentin bridge/reparative dentin formation during the pulp healing process at different follow-up periods, using different capping materials. Conclusions: Mineral trioxide aggregate (MTA) and Biodentine can induce dentin regeneration when applied over exposed pulp. This systematic review can conclude that MTA and its variants have better efficacy in the DPC procedure for dentin regeneration.