A hybrid approach to direct pulp capping by using emdogain with a capping material

Biocompatibility and Bioactivity of a Dual-Cured Resin-Based Calcium Silicate Cement: In Vitro and in vivo Evaluation

INTRODUCTION

This study aimed to assess the biocompatibility and bioactivity of a dual-cured resin-based calcium silicate cement in vitro and in vivo.

METHODS

For in vitro analyses, standardized samples were prepared using TheraCal LC, TheraCal PT, and ProRoot MTA. The amount of residual monomer released from TheraCal LC and TheraCal PT was assessed using liquid chromatography/mass spectrometry. Calcium ion release from the materials was evaluated using inductively coupled plasma-optical emission spectroscopy. Scanning electron microscopy and energy-dispersive X-ray spectroscopy were used to determine the calcium weight volume in the materials. For in vivo analysis, a rat direct pulp capping model with TheraCal LC, TheraCal PT, and ProRoot MTA groups (n = 16 per group) was used. The rats were euthanized after 7 or 28 days, and histological and immunohistochemical analyses (CD68 and DSPP) were performed.

RESULTS

Bisphenol A-glycidyl methacrylate and polyethylene glycol dimethacrylate release from TheraCal PT was lower than that from TheraCal LC (P < .05). Similar results were obtained for calcium-ion release and calcium weight volume, with ProRoot MTA showing the highest values. In the in vivo evaluation, TheraCal PT showed significantly greater hard tissue formation than TheraCal LC (P < .017). TheraCal PT showed lower CD68 expression and greater DSPP expression than TheraCal LC (P < .017). There were no significant differences in the expression of CD68 or DSPP between the TheraCal PT and ProRoot MTA groups.

CONCLUSIONS

Within the limitations of this study, the biocompatibility and bioactivity of TheraCal PT could be comparable to those of ProRoot MTA.

Histological Evaluation of Pulpal Response and Dentin Bridge Formation After Direct Pulp Capping Using Recombinant Amelogenin and Mineral Trioxide Aggregate (MTA)

The purpose of the study was to compare and histologically investigate pulpal response and dentin bridge formation after direct pulp capping using recombinant amelogenin and mineral trioxide aggregate (MTA). Recombinant amelogenin protein and MTA were used as pulp capping materials in 120 teeth from eight mongrel dogs. Dogs were sacrificed at two different evaluation times. Regenerative changes were evaluated histologically. At two weeks, in contrast to the MTA group, most of the amelogenin group showed moderately formed hard tissue formation and the pulp tissue was completely filling the entire pulp chamber. These results were statistically significant. At two months, all the samples of the amelogenin group showed complete dentin bridge formation and the pulp chamber was filled entirely with tissue-mimicking the authentic pulp in all the specimens of the amelogenin group. These results were statistically significant. In conclusion, direct pulp capping by recombinant amelogenin protein resulted in significantly better regeneration of the dentin-pulp complex than MTA.

Physiologic dentin regeneration: its past, present, and future perspectives

Regenerative dentistry has rapidly progressed since the advancement of stem cell biology and material science. However, more emphasis has been placed on the success of tissue formation than on how well the newly generated tissue retains the original structure and function. Once dentin is lost, tertiary dentinogenesis can be induced by new odontoblastic differentiation or re-activation of existing odontoblasts. The characteristic morphology of odontoblasts generates the tubular nature of dentin, which is a reservoir of fluid, ions, and a number of growth factors, and protects the inner pulp tissue. Therefore, understanding the dynamic but delicate process of new dentin formation by odontoblasts, or odontoblast-like cells, following dentinal defects is crucial. In this regard, various efforts have been conducted to identify novel molecules and materials that can promote the regeneration of dentin with strength and longevity. In this review, we focus on recent progress in dentin regeneration research with biological molecules identified, and discuss its potential in future clinical applications.

Comparative evaluation of treatment outcome of partial pulpotomy using different agents in permanent teeth-a randomized controlled trial

AIM

To compare and evaluate the clinical and radiographic performance, post-operative pain, and anti-inflammatory intake after partial pulpotomy (PP) with calcium hydroxide (CH), mineral trioxide aggregate (MTA), Biodentine (BD), and Emdogain (EMD) as pulp capping agents in mature permanent molars with definitive diagnosis of reversible pulpitis.

MATERIALS AND METHODS

As part of this prospective, randomized clinical trial with four parallel arms (CTRI Registration No.: CTRI/2020/11/029329 dated 24/11/2020), hundred and ten permanent molars with a clinical diagnosis of reversible pulpitis and normal apical tissues, from patients between the ages of 15 and 45 years, were recruited and randomly assigned to four groups-CH, MTA, BD, and EMD. Operative procedure was performed under local anesthesia and dental dam isolation. After carious pulpal exposure, 2 mm of superficially inflamed coronal pulp tissue was amputated and either of the four pulp capping materials was placed. The outcome assessment was carried out at 1, 3, 6, and 12 month(s) and was categorized as success (asymptomatic patients with PAI score = 1) or failure (symptomatic patients or PAI score > 1).

RESULTS

There was a significant difference in post-operative pain and anti-inflammatory medication intake after partial pulpotomy with Emdogain vis-à-vis other three capping agents. No difference in both clinical and radiographic performances was observed among the four capping agents.

CONCLUSION

Partial pulpotomy when performed following evidence-based guidelines results in high success rates regardless of capping agent employed. EMD can be considered a valid and suitable pulp capping agent in PP.

CLINICAL RELEVANCE

Meticulous examination and removal of superficially inflamed pulp under magnification and complete asepsis lead to successful pulpal healing regardless of capping agent employed.

Evaluating the potential of an amelogenin-derived peptide in tertiary dentin formation

Several novel biomaterials have been developed for dental pulp capping by inducing tertiary dentin formation. The aim of this study was to evaluate the effect of QP5, an amelogenin-based peptide, on the mineralization of dental pulp cells (DPCs) in vitro and in vivo. The cell viability of human DPCs (hDPCs) after treatment with QP5 was determined using the Cell Counting Kit-8 (CCK-8). Migration of hDPCs was assessed using scratch assays, and the pro-mineralization effect was determined using alkaline phosphatase (ALP) staining, alizarin red staining and the expression of mineralization-related genes and proteins. The results showed that QP5 had little effect on the cell viability, and significantly enhanced the migration capability of hDPCs. QP5 promoted the formation of mineralized nodules, and upregulated the activity of ALP, the expression of mRNA and proteins of mineralization-related genes. A pulp capping model in rats was generated to investigate the biological effect of QP5. The results of micro-computed tomography and haematoxylin and eosin staining indicated that the formation of tertiary dentin in QP5-capping groups was more prominent than that in the negative control group. These results indicated the potential of QP5 as a pulp therapy agent.

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

OBJECTIVES

To assess clinically and radiographically the success of pulp capping procedure done in traumatically exposed permanent posterior teeth using a novel injectable treated dentin matrix hydrogel (TDMH), Biodentine, and MTA and to evaluate the formed dentin bridge under the capping materials using CBCT imaging.

MATERIALS AND METHODS

45 patients subjected to accidental traumatic pulp exposures by undergraduate dental students are allocated for this study. For each patient, a pulp capping procedure was done. TDMH was formed of TDM powder and sodium alginate to be injected and then hardened in the defect area. Patients were assigned to 3 groups: TDMH, Biodentine, and MTA, respectively, and returned to the clinic after 3, 6, 12, 18, and 24 months for clinical and radiographic examinations. Tomographic data, including thickness and density of formed dentin bridges, were evaluated at the end of the study period compared to the base line. Pulp sensitivity was evaluated throughout the study period using thermal testing and electric pulp tester.

RESULTS

During the follow-up period, all patients were asymptomatic with no clinical signs and symptoms and revealed no radiographic signs of pathosis. However, tomographic evaluation showed the tested materials to have different levels of impact on formed dentin bridges with TDMH group resulted in significantly superior dentin bridges of a higher radiodensity and thickness than Biodentine and MTA.

CONCLUSIONS

TDMH has a greater potential to induce dentin bridge formation than Biodentine and MTA under standardized conditions. Additionally, CBCT imaging was confirmed as a non-invasive and inclusive approach to evaluate the formed dentin bridges after pulp capping procedure.

CLINICAL RELEVANCE

Direct pulp capping can be done successfully with this novel injectable pulp capping material in future clinical applications.

TRIAL REGISTRATION

PACTR201901866476410.

Injectable Biomaterials for Dental Tissue Regeneration

Injectable biomaterials scaffolds play a pivotal role for dental tissue regeneration, as such materials are highly applicable in the dental field, particularly when compared to pre-formed scaffolds. The defects in the maxilla-oral area are normally small, confined and sometimes hard to access. This narrative review describes different types of biomaterials for dental tissue regeneration, and also discusses the potential use of nanofibers for dental tissues. Various studies suggest that tissue engineering approaches involving the use of injectable biomaterials have the potential of restoring not only dental tissue function but also their biological purposes.

[Recent advances in direct pulp capping materials]

The long-term effect of direct pulp capping and pulpotomy is closely related to the type of pulp capping materials. Various kinds of direct pulp capping materials are available, such as calcium hydroxide and mineral trioxide aggregates. Diverse new pulp capping materials have been reported recently. The excellent performance of calcium silicates has attracted much attention in previous studies. Moreover, enamel matrix derivative (Emdogain), which is capable of regeneration and remineralization, and other materials with similar capabilities have shown potential for use in pulp capping.

The Efficacy of Recombinant Platelet-Derived Growth Factor on Beta-Tricalcium Phosphate to Regenerate Femoral Critical Sized Segmental Defects: Longitudinal In Vivo Micro-CT Study in a Rat Model

Background and Objectives: Beta-tricalcium phosphate (beta-TCP) has been used for bone regeneration. The objective of this study was to assess longitudinally, the regeneration of critical sized segmental defects (CSSD) in rat femur using beta-TCP with or without recombinant platelet-derived growth factor (PDGF) through in vivo micro-computed tomography (micro-CT). Materials and Methods: Following ethical approval unilateral femoral CSSD measuring 5 mm was surgically created, under general anesthesia, in 30 male Wistar-Albino rats (aged 12-18 months; weighing 450-500 g). CSSD was stabilized using titanium mini-plate (4 holes, 1.0 mm thick with 8 mm bar). Depending upon biomaterial used for regeneration, the animals were randomly divided into: Control group (N = 10): CSSD covered with resorbable collagen membrane (RCM) only; Beta-TCP group (N = 10): CSSD filled with beta-TCP and covered by RCM; Beta-TCP + PDGF group (N = 10): CSSD filled with beta-TCP soaked in recombinant PDGF and covered by RCM. Longitudinal in vivo micro-CT analysis of the CSSD was done postoperatively at baseline, 2nd, 4th, 6th, and 8th weeks to assess volume and mineral density of newly formed bone (NFB) and beta-TCP. Results: Significant increase in NFB volume (NFBV) and mineral density (NFBMD) were observed from baseline to 8-weeks in all groups. Based on longitudinal in vivo micro-CT at 8-weeks, beta-TCP + PDGF group had significantly higher (p < 0.01) NFBV (38.98 ± 7.36 mm³) and NFBMD (3.72 ± 0.32 g/mm³) than the beta-TCP (NFBV-31.15 ± 6.68 mm³; NFBMD-2.28 ± 0.86g/mm³) and control (NFBV: 5.60 ± 1.06 mm³; NFBMD: 0.27 ± 0.02 g/mm³) groups. Significantly, higher reduction in beta-TCP volume (TCPV) and mineral density (TCPMD) were 1 observed in the beta-TCP + PDGF group when compared to the beta-TCP group. Conclusion: Addition of recombinant PDGF to beta-TCP enhanced bone regeneration within rat femoral CSSD and increased resorption rates of beta-TCP particles.

Clinical and Molecular Perspectives of Reparative Dentin Formation: Lessons Learned from Pulp-Capping Materials and the Emerging Roles of Calcium

The long-term use of calcium hydroxide and the recent increase in the use of hydraulic calcium-silicate cements as direct pulp-capping materials provide important clues in terms of how reparative dentin may be induced to form a "biological seal" to protect the underlying pulp tissues. In this review article, we discuss clinical and molecular perspectives of reparative dentin formation based on evidence learned from the use of these pulp-capping materials. We also discuss the emerging role of calcium as an odontoinductive component in these pulp-capping materials.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part I: vital pulp therapy

Mineral trioxide aggregate (MTA) is a bioactive endodontic cement (BEC) mainly comprised of calcium and silicate elements. The cement was introduced by Torabinejad in the 1990s and has been approved by the Food and Drug Administration to be used in the United States in 1997. A number of new BECs have also been introduced to the market, including BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, NeoMTA Plus, OrthoMTA, Quick-Set, RetroMTA, Tech Biosealer and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA without its drawbacks. In this article, the chemical composition and the application of MTA and other BECs for vital pulp therapy (VPT), including indirect pulp cap, direct pulp cap, partial pulpotomy, pulpotomy and partial pulpectomy, have been reviewed and compared. Based on selected keywords, all papers regarding chemical composition and VPT applications of BECs had been reviewed. Most of the materials had calcium and silicate in their composition. Instead of referring to the cements based on their chemical compositions, we suggest the term 'bioactive endodontic cements (BECs)', which seems more appropriate for these materials because, in spite of differences in their chemical compositions, bioactivity is a common property for all of them. Numerous articles were found regarding use of BECs as VPT agents for indirect and direct pulp capping, partial pulpotomy and cervical pulpotomy. Most of these investigations used MTA for VPT. In most studies, newly introduced materials have been compared to MTA. Some of the BECs have shown promising results; however, the number of their studies compared to investigations on MTA is limited. Most studies had several methodological shortcomings. Future investigations with rigorous methods and materials are needed.

Clinical and histological responses of human dental pulp to MTA and combined MTA/treated dentin matrix in partial pulpotomy

The aim of this study was to compare the responses of mineral trioxide aggregate (MTA) and combined MTA/treated dentin matrix (TDM) as direct pulp capping material. In this clinical trial study, 33 intact third molars in 11 healthy volunteers (three molars in each) were included. Partial pulpotomies were performed in a split mouth manner in two of the third molars in each patient randomly and the third tooth had used as TDM source. The coronal dentin was chopped to dentine chips and transformed to TDM using different concentrations of ethylene diamine tetraacetic acid (EDTA) solution. Pulps were directly capped by MTA alone or using a combination layering of MTA/TDM. Following 6-week clinical and radiological evaluations, each tooth was extracted and prepared for histological evaluation. There were no significant differences in the clinical and radiographic responses or in the quality of dentin bridges (P > 0.05). However, the dentin bridge was significantly thicker in MTA/TDM group than MTA group (P = 0.003). Using the combination of MTA/TDM as a pulp-dressing agent may form a thicker dentin bridge compared to MTA alone.

Biological evaluation of a new pulp capping material developed from Portland cement

This study evaluates the biological properties of a new pulp capping material developed from Portland cement. This study was conducted on 48 teeth in 4 dogs (12 teeth/dog). The dogs were classified into two equal groups (n=24 teeth) according to the evaluation period including: group A (3 weeks) and group B (3 months). Each group was further subdivided into three equal subgroups (n=8 teeth) according to the capping material including: subgroup 1: mineral trioxide aggregate (MTA), subgroup2: Portland cement+10% calcium hydroxide+20% bismuth oxide (Port Cal) and subgroup 3: Portland cement+bismuth oxide. After general anesthesia, a class V buccal cavity was prepared coronal to the gingival margin. After pulp exposure and hemostasis,the capping materials and glass ionomer filling were placed on the exposure sites. All histopathological findings, inflammatory cell count and dentin bridge formation were recorded. Data were analyzed statistically. After 3 months, the histopathological picture of the pulp in subgroup 1 showed normal pulp, continuous odontoblastic layer and complete dentin bridge formation while subgroup 2 showed partial and complete dentin bridge over a normal and necrotic pulps. Subgroup 3 showed loss of normal architecture, areas of necrosis, complete, or incomplete dentin bridge formation, attached and detached pulp stones and fatty degeneration in group B. For group A, MTA subgroup showed the least number of inflammatory cell infiltrate followed by Port Cal subgroup. While subgroup 3 showed the highest number of inflammatory cell infiltrate. For group B, the mean inflammatory cell count increased with the three tested materials with no statistical difference. Regarding dentin bridge formation at group A, no significant differences was found between subgroups, while at group B, MTA subgroup exhibited significantly higher scores than other subgroups. In conclusion, addition of calcium hydroxide to Portland cement improves the dentin bridge formation qualitatively and quantitatively.

Histological evaluation of mineral trioxide aggregate and enamel matrix derivative combination in direct pulp capping: An in vivo study

AIM

The aim of this study is to evaluate the response of human pulp tissue to mineral trioxide aggregate (MTA), Emdogain (EMD), and combination of MTA/EMD.

MATERIALS AND METHODS

This study was performed on sixty intact first and second premolars of human maxillary and mandibular teeth. A standard pulpal exposure was done on all the teeth and was divided into three groups of twenty teeth each and was capped with MTA, EMD, and MTA/EMD combination. The final restoration was done with resin-modified glass ionomer cement. The teeth were then extracted on the 15^th or 45^th day and histological evaluation done.

RESULTS

Differences in inflammatory response and thickness of dentin bridge formation of the exposed pulp to the three different groups were statistically evaluated using Chi-square and Mann-Whitney tests and were found to be significant. No significant difference was found between MTA/EMD and MTA in terms of calcified bridge formation and pulp inflammatory response to the capping materials.

CONCLUSIONS

MTA and MTA/EMD combination produced a better quality hard tissue response compared with the use of EMD.

In vitro and in vivo evaluation of a nanoparticulate bioceramic paste for dental pulp repair

Bioactive materials play an important role in facilitating dental pulp repair when living dental pulp is exposed after injuries. Mineral trioxide aggregate is the currently recommended material of choice for pulp repair procedures though has several disadvantages, especially the inconvenience of handling. Little information is yet available about the early events and molecular mechanisms involved in bioceramic-mediated dental pulp repair. We aimed to characterize and determine the apatite-forming ability of the novel ready-to-use nanoparticulate bioceramic iRoot BP Plus, and investigate its effects on the in vitro recruitment of human dental pulp stem cells (DPSCs), as well as its capacity to induce dentin bridge formation in an in vivo model of pulp repair. It was found that iRoot BP Plus was nanosized and had excellent apatite-forming ability in vitro. Treatment with iRoot BP Plus extracts promoted the adhesion, migration and attachment of DPSCs, and optimized focal adhesion formation (Vinculin, p-Paxillin and p-Focal adhesion kinase) and stress fibre assembly. Consistent with the in vitro results, we observed the formation of a homogeneous dentin bridge and the expression of odontogenic (dentin sialoprotein, dentin matrix protein 1) and focal adhesion molecules (Vinculin, p-Paxillin) at the injury site of pulp repair model by iRoot BP Plus. Our findings provide valuable insights into the mechanism of bioceramic-mediated dental pulp repair, and the novel revolutionary ready-to-use nanoparticulate bioceramic paste shows promising therapeutic potential in dental pulp repair application.

Recent advances in pulp capping materials: an overview

Emphasis has shifted from the "doomed" organ concept of an exposed pulp to one of hope and recovery. The era of vital-pulp therapy has been greatly enhanced with the introduction of various pulp capping materials. The aim of this article is to summarize and discuss about the various and newer pulp capping materials used for protection of the dentin-pulp complex.

Ionic extraction of a novel nano-sized bioactive glass enhances differentiation and mineralization of human dental pulp cells

INTRODUCTION

This study aimed to investigate the effects of a novel nano-sized 58S bioactive glass (nano-58S BG) on the odontogenic differentiation and mineralization of human dental pulp cells (hDPCs) in vitro.

METHODS

Extractions were prepared by incubating nano-58S BG, 45S5 BG, or 58S BG particulates in Dulbecco modified Eagle medium at 1% w/v for 24 hours and were filtrated through 0.22-μm filters. The supernatants were used as BG extractions. The hDPCs were cultured in nano-58S BG, 45S5 BG, and 58S BG extractions. The proliferation of hDPCs was evaluated using the methylthiazol tetrazolium assay. Odontogenic differentiation was evaluated based on the real-time polymerase chain reaction of differentiation- and mineralization-related genes, namely, alkaline phosphatase (ALP), collagen type I, dentin sialophosphoprotein (DSPP), and dentin matrix protein 1. The gene expressions were verified using ALP activity assessment, immunocytochemistry staining of osteocalcin and DSPP, and mineralization assay using alizarin red S stain.

RESULTS

All BG extractions up-regulated the expression of odontogenic genes, and the most significant enhancement was in the nano-58S BG group. All BG extractions, especially nano-58S, increased ALP activity, osteocalcin and DSPP protein production, and mineralized nodules formation.

CONCLUSIONS

Compared with regular BG, the novel nano-58S BG can induce the differentiation and mineralization of hDPCs more efficiently and might be a better potential candidate for dentin-pulp complex regeneration.

Prognostic factors for clinical outcomes according to time after direct pulp capping

INTRODUCTION

Direct pulp capping is a treatment option for teeth with carious-exposed pulp. Because pulp capping studies have exhibited fluctuations in success rates according to different follow-up times, investigating the clinical pulpal survival rate and the potential factors contributing to the survival with respect to time is necessary.

METHODS

A total of 175 patients treated between November 2007 and August 2010 met the inclusion criteria. During the follow-up, we investigated 7 clinical variables with respect to the survival of the pulp capping treatment: sex, age, maxilla versus mandible, tooth position, capping materials, temporary filling materials, and exposure site. Survival analysis was performed using the Kaplan-Meier method and the Cox proportional hazard regression model.

RESULTS

The Kaplan-Meier survival curves and log-rank tests revealed that only age, exposure site, and capping material had significant effects on the pulpal survival rate (P< .05). A Cox regression model showed that mineral trioxide aggregate was the sole factor affecting the survival of the treated pulps (P< .05). In the analyses performed separately according to time, there was no conspicuous factor that affected the survival rate before 100 days. However, after 100 days, the type of pulp capping material was the single most important factor influencing the survival rate (P< .05).

CONCLUSIONS

The results of this study indicated that careful patient selection and the type of pulp capping material should be taken into consideration when performing a pulp capping treatment.

Quantitative determination of high-temperature requirement protein A1 and its possible associated molecules during induced reparative dentin formation

INTRODUCTION

The equilibrium of inhibitors and inducers plays an important role in the mineralization of dentin during dentinogenesis. High-temperature requirement protein A1 (HtrA1) is a novel bone mineralization inhibitor involved in physiological and pathological bone formation. However, the expression of HtrA1 in tooth mineralization is unknown. The purpose of the present study was to investigate the localization and quantity of HtrA1 and its possible related molecules during induced reparative dentin formation.

METHODS

Rats were randomly sacrificed after direct pulp capping on days 0, 7, 14, and 21. Maxillary segments were obtained and routinely prepared for histological analysis, immunohistochemistry, quantum dots-based double immunofluorescence, and CRi's Nuance imaging system (CRI, Woburn, MA)-based quantitative determination.

RESULTS

The square measure values of reparative dentin significantly increased on day 7 and continued to increase until day 21. HtrA1, matrix Gla protein (MGP), nestin, and bone sialoprotein were positively stained and colocalized in the odontoblasts and/or odontoblast-like cells zone and reparative dentin during induced reparative dentin formation. The expressions of HtrA1 and MGP were significantly enhanced after direct pulp capping on day 7 and did not significantly change between days 7, 14, and day 21. Both expressions of HtrA1 and MGP were positively correlated with the square measure values of reparative dentin; however, no correlation was found between the expressions of HtrA1 and MGP.

CONCLUSIONS

HtrA1 could be observed and might possibly be involved in the process of reparative dentin formation associated with MGP.