Similar sealability between bioceramic putty ready-to-use repair cement and white MTA

Comparison of Marginal Adaptation, Surface Hardness and Bond Strength of Resected and Retrofilled Calcium Silicate-based Cements Used in Endodontic Surgery: An In Vitro Study

AIMS

This study compared the effects of orthograde and retrograde methods on marginal adaptation, surface hardness, and push-out bond strength (POBS) of three calcium silicate-based used in endodontic surgery.

MATERIALS AND METHODS

Ninety single-rooted human mandibular premolars were randomly assigned into six groups (n = 15/group): groups I and II, ProRoot mineral trioxide aggregate (MTA) with orthograde and retrograde methods; groups III and IV, Biodentine (BD) with orthograde and retrograde methods; groups V and VI, iRoot BP Plus (BP-RPM) with orthograde and retrograde methods. After obturation, the apical 3 mm of each root was sectioned into two 1-mm-thick root slices and evaluated for marginal adaptation using a scanning electron microscope, surface hardness using Vickers hardness tester and POBS using a universal testing machine.

RESULTS

Orthograde placement had a higher maximum gap width than retrograde placement (p < 0.05), but there was no significant difference among the tested materials (p > 0.05). Biodentine exhibited lower surface hardness than ProRoot MTA and iRoot BP Plus (p < 0.05), but there was no significant difference between ProRoot MTA and iRoot BP Plus (p > 0.05). Orthograde placement had higher POBS compared with retrograde placement (p < 0.05). Biodentine had higher POBS than iRoot BP Plus (p < 0.05), but no significant difference from ProRoot MTA (p > 0.05). The failure mode was mainly mixed for all the tested materials regardless of material type or placement technique.

CONCLUSION

The retrograde method had better marginal adaptation; however, the orthograde method provided better dislodgement resistance. Biodentine had lower surface hardness than MTA and iRoot BP Plus with both techniques, whereas iRoot BP Plus demonstrated lower dislodging resistance than BD.

CLINICAL SIGNIFICANCE

The current findings suggest that orthograde technique, a simpler periapical surgery, with ProRoot MTA provides potentially better surface hardness and POBS than BD and iRoot BP Plus in single-canal teeth.

Bioceramics in Endodontics: Updates and Future Perspectives

Bioceramics, with excellent bioactivity and biocompatibility, have been widely used in dentistry, particularly in endodontics. Mineral trioxide aggregate (MTA) is the most widely used bioceramic in endodontics. Recently, many new bioceramics have been developed, showing good potential for the treatment of endodontic diseases. This paper reviews the characteristics of bioceramics and their applications in various clinical endodontic situations, including root-end filling, root canal therapy, vital pulp therapy, apexification/regenerative endodontic treatment, perforation repair, and root defect repair. Relevant literature published from 1993 to 2023 was searched by keywords in PubMed and Web of Science. Current evidence supports the predictable outcome of MTA in the treatment of endodontic diseases. Although novel bioceramics such as Biodentine, EndoSequence, and calcium-enriched mixtures have shown promising clinical outcomes, more well-controlled clinical trials are still needed to provide high-level evidence for their application in endodontics. In addition, to better tackle the clinical challenges in endodontics, efforts are needed to improve the bioactivity of bioceramics, particularly to enhance their antimicrobial activity and mechanical properties and reduce their setting time and solubility.

Fracture Resistance of Molars With Simulated Strip Perforation Repaired With Different Calcium Silicate-Based Cements

Background and aims A root perforation is a connection between the root canal system and the external supportive tissues. Strip perforation (SP), occurring within root canals in a strip, can worsen the prognosis of a treated tooth, reduce its mechanical resistance, and impair the tooth structure. One of the suggested methods to treat SP is to seal it with a bio-material such as calcium silicate cement. Therefore, this in vitro study aimed to assess the molar structure impairment due to SP, which requires studying the fracture resistance, and the ability of mineral trioxide aggregate (MTA), bioceramic, and calcium-enriched mixture (CEM) to repair this perforation. Materials and methods Seventy-five molars were instrumented to size #25 and taper 4%, irrigated with sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA), dried, and then divided randomly into five groups (G1-G5): in G1, root canals were filled with gutta-percha and sealer (negative control sample), whereas the rest of the groups (G2-G5) had a manual simulated SP made with Gates Glidden drill at the mesial root of the extracted molar, and filled with gutta-percha and sealer up to their perforation area; in G2, SP was filled with gutta-percha and sealer (positive control sample); G3 used MTA to repair the SP; G4 used bioceramic putty; and G5 used CEM. Fracture resistance tests of the molars were conducted in the crown-apical direction using a universal testing machine. One-way ANOVA test and Bonferroni test were used to study the significance of the differences in the mean values of the tooth fracture resistance, where statistical significance was set at 0.05. Results The ANOVA test showed that there were statistically significant differences between the fracture resistance (in newtons) values among groups (p = 0.000). The Bonferroni test showed that G2 had a smaller fracture resistance mean than the other four study groups (656.53 N; p = 0.000), and that of G5 was smaller than G1, G3, and G4 (794.40 N, 1083.73 N, 1025.20 N, and 1034.20 N, respectively; p = 0.000 in each pairwise comparison). Conclusion SP reduced the fracture resistance of endodontically treated molars. SP restored using MTA and bioceramic putty was better than that treated with CEM and similar to molars without SP. Moreover, MTA and bioceramic putty enhanced the fracture resistance of endodontically treated teeth to levels similar to molars without SP.

Dislodgement pushout resistance of five bioceramic root-end filling materials

This study evaluated the dislodgement push-out resistance of five bioceramic materials. One hundred single-rooted teeth with one canal had the apical 3 mm and crown resected to create a 14 mm standardized length. The canals were instrumented to an apical size 80 with a 3 mm root-end preparation made with ultrasonic diamonds. The prepared roots were randomly divided into 5 root-end restorative groups (n=20). ProRoot MTA, Biodentine, EndoSequence Root Repair Material, EndoSequence Fast Set Putty, and EndoSequence BC Sealer with each material placed following manufacturer's instructions and stored at 100% humidity for 2 weeks. An apical-to-coronal static testing load with the identified dislodgement force converted into MPa with mean results analyzed with Kruskal-Wallis and Dunn's post hoc tests (α=0.05). ProRoot MTA and Biodentine displayed similar push-out stress resistance and exhibited significantly greater stress resistance than the similar Endosequence materials. However, all materials failed cohesively and were not dislodged from the root canal surface.

Bio-C Repair - A New Bioceramic Material for Root Perforation Management: Two Case Reports

These case reports aimed to describe the management of lateral perforation in the middle cervical third of the root in two maxillary incisors with pulp canal calcification using Bio-C Repair, with safe and viable clinical treatment strategies. Digital radiographic exams were obtained with different angles and analyzed using different filters. Cone-beam computed tomography (CBCT) images were requested to show the actual position of the canal, location of the perforation, and guide the strategic planning of the case. Subsequently, cavity access was prepared with the aid of dental operating microscopy. After perforation was identified, granulation tissue was removed and the original canal was identified and then dressed with calcium hydroxide. In the second visit, the perforation was filled with Bio-C Repair and the canal system filled with gutta-percha points and a root canal sealer (Bio-C Sealer). The teeth were restored with glass fiber post, 4 mm beyond the perforation level, and provisory crowns. Both teeth treated as described above were functional and asymptomatic with a 1-year clinical and radiographic assessment. The Bio-C Repair is suggested as a new cement option for the management of lateral canal perforations, with effective results as observed after a one-year follow-up.

Comparison between iRoot BP Plus (EndoSequence Root Repair Material) and Mineral Trioxide Aggregate as Pulp-capping Agents: A Systematic Review

INTRODUCTION

iRoot BP Plus, also known as EndoSequence root repair material (EERM) is a premixed bioceramic thick/putty. According to its instruction manual, iRoot BP Plus is composed of tricalcium silicate, zirconium oxide, tantalum pentoxide, dicalcium silicate, calcium sulfate, calcium phosphate monobasic, and filler agents. This systematic review was carried out to evaluate and present the iRoot BP Plus material as a pulp-capping agent.

MATERIALS AND METHODS

A systematic search for articles with the scope of the selection criteria undergoing for data extraction was conducted through electronic databases. Studies on evaluation of the cytotoxicity, bioactivity, and dentinal bridge formation of iRoot BP, iRoot BP Plus, ERRM putty, or ERRM paste (ERRM) on variant human cells were selected for in vitro models, and dentinal bridge formation on human and animals teeth for in vivo models were selected.

RESULTS

A total of 22 articles were discussed in the review, 14 in vitro studies, five in vivo studies, and three articles with both studies. Methyl thiazol tetrazolium was the most used method for evaluating cytotoxicity. As for dentinal bridge formation, histological assessment and micro-Computed tomography were used. Human dental pulp cells (hDPCs) were the most investigated for in vitro models and rats for in vivo models. Except for one study, all studies involved in this review were primarily examining the material and comparing it to different types of mineral trioxide aggregate.

CONCLUSION

iRoot BP, iRoot BP Plus, and ERRM are biocompatible materials that enhance hDPCs and other variant human cells proliferation, migration, attachment adhesion, mineralization, and dentinal bridge formation.

iRoot BP Plus promotes osteo/odontogenic differentiation of bone marrow mesenchymal stem cells via MAPK pathways and autophagy

BACKGROUND

iRoot BP Plus is a novel bioceramic endodontic material. Recently, it has been considered as an alternative to MTA which is the most popular scaffold cover during regenerative endodontic therapy. This study aimed to evaluate the effects of iRoot BP Plus on the osteo/odontogenic capacity of bone marrow mesenchymal stem cells (BMMSCs), including the underlying mechanisms.

METHODS

BMMSCs were collected by a whole marrow method and treated with iRoot BP Plus-conditioned medium (BP-CM). The proliferation ability was evaluated by cell counting kit 8 and flow cytometry. Complete medium was used as a blank control, and 2 mg/ml MTA-conditioned medium was served as a positive control. Alkaline phosphatase (ALP) activity assay, ALP staining, western blot, real-time RT-PCR, Alizarin Red S staining, and immunofluorescence staining were performed to explore the osteo/odontogenic potential and the involvement of MAPK pathways. Besides, autophagy was investigated by western blot, immunofluorescence staining, and transmission electron microscopy.

RESULTS

Effects of mineral trioxide aggregate and bioceramics on macrophage differentiation and polarization in vitro

BACKGROUND/PURPOSE

Mineral trioxide aggregate (Pro-Root MTA, PR-MTA) and bioceramics (iRoot^® SP Injectable Root Canal Sealer, iR-BC) are used for making apical plugs used in apexification, repairing root perforations during root canal therapy, and treating internal root resorption. The purpose of the present in vitro study was to compare the biological effects of PR-MTA- and iR-BC-based dental sealers in the mouse macrophage cell line RAW 264.7.

METHODS

Cytotoxicity and cell proliferation were analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and cell hemocytometer, respectively. Protein expression of biomarkers of cell proliferation, autophagy, and osteoclast differentiation was determined by western blotting. Pro-inflammatory gene expression was examined using quantitative reverse transcription-PCR.

RESULTS

PR-MTA induced cytotoxicity in RAW 264.7 cells in a dose-dependent manner, and iR-BC was more cytotoxic than PR-MTA. Low-dose and short-term treatments of both PR-MTA and iR-BC induced RAW 264.7 cell proliferation. PR-MTA induced autophagy, whereas iR-BC did not. Neither PR-MTA nor iR-BC induced osteoclastogenesis. Pro-inflammatory genes were activated by both materials. However, the expression of inducible nitric oxide synthase (iNOS) mRNA was upregulated by iR-BC treatment, but not by PR-MTA treatment.

CONCLUSION

Overall, dental PR-MTA and iR-BC induced pro-inflammatory genes but did not induce osteoclastogenesis in macrophages. PR-MTA and iR-BC induced M2 and M1 polarization, respectively, of RAW 264.7 cells.

The use of Bioceramics as root-end filling materials in periradicular surgery: A literature review

Introduction

Periradicular surgery involves the placement of a root-end filling following root-end resection, to provide an apical seal to the root canal system. Historically several materials have been used in order to achieve this seal. Recently a class of materials known as Bioceramics have been adopted. The aim of this article is to provide a review of the outcomes of periradicular surgery when Bioceramic root-end filling materials are used on human permanent teeth in comparison to "traditional" materials.

Methods & results

An electronic literature search was performed in the databases of Web of Science, PubMed and Google Scholar, between 2006 and 2017, to collect clinical studies where Bioceramic materials were utilised as retrograde filling materials, and to compare such materials with traditional materials. In this search, 1 systematic review and 14 clinical studies were identified. Of these, 8 reported the success rates of retrograde Bioceramics, and 6 compared treatment outcomes of mineral trioxide aggregate (MTA) and traditional cements when used as root-end filling materials.

Conclusion

Bioceramic root-end filling materials are shown to have success rates of 86.4-95.6% (over 1-5 years). Bioceramics has significantly higher success rates than amalgam, but they were statistically similar to intermediate restorative material (IRM) and Super ethoxybenzoic acid (Super EBA) when used as retrograde filling materials in apical surgery. However, it seems that the high success rates were not solely attributable to the type of the root-end filling materials. The surgical/microsurgical techniques and tooth prognostic factors may significantly affect treatment outcome.

Importance and methodologies of endodontic microleakage studies: A systematic review

INTRODUCTION

It is very important to obtain a tight seal in obturated root canal, making it necessary to conduct clinical or laboratory studies on the sealability of endodontic materials. Different methodologies have been historically used to assess microleakage of different endodontic materials. The aim of the present study was to comprehensively review different material testing methods used in microleakage studies, their interpretation and importance in endodontic literature.

MATERIAL AND METHODS

A systematic search was conducted in Medline, Cochrane, and Web of Science databases. In addition, the reference lists of review articles on the topic were searched. No language restriction was applied. Two independent reviewers screened the article.

RESULTS

Microleakage is considered the single most important risk factor responsible for apical periodontitis. Dye penetration, dye diffusion, bacterial and endototoxin infiltration, fluid filtration, glucose, caffeine and protein infiltration, radioisotope penetration, animal studies, and electrochemical or 3D evaluation are different methodologies used to assess dental leakage. 91 out of 177 articles in the primary search were included in the study. These methods are very divergent in their viewpoints; that is why their results cannot be easily compared. It is necessary to standardize microleakage detection methods in order to more correctly evaluate the phenomena that are found between the root canal wall and the root canal filling materials.

CONCLUSIONS

All the methods are useful if studies are performed strictly with large sample sizes and proper control groups and if the technique can be standardized. Furthermore, more evaluations of the reliability of the methods are strongly recommended. Key words:Dental leakage, review, root canal, material testing methods, data interpretation.

Effect of Silver Nanoparticles on Physicochemical and Antibacterial Properties of Calcium Silicate Cements

Mineral trioxide aggregate (MTA) and Portland cement (PC) are calcium silicate cements. They have similar physicochemical, mechanical and biological properties. The addition of zirconium oxide (ZrO2) to PC provides radiopacity. Silver nanoparticles (AgNPs) may improve some properties of cements. The aim of this study was to evaluate the effect of AgNPs on physicochemical/mechanical properties and antibacterial activity of white MTA (WMTA) and PC associated with ZrO2. The following materials were evaluated: WMTA; PC 70% + ZrO2 30%; WMTA+ AgNPs; and PC 70% + ZrO2 30% + AgNPs. The study evaluated radiopacity, setting time, pH, compressive strength and solubility. For radiopacity analysis, radiographs were made alongside an aluminum (Al) step wedge. To evaluate the antibacterial activity, direct contact test was performed on planktonic cells and Enterococcus faecalis biofilm induced on bovine root dentin for 14 days. The experimental periods were 5 and 15 h. Data were obtained as CFU mL-1. The obtained data were submitted to ANOVA and Tukey tests (p<0.05). The addition of AgNPs to WMTA increased the pH, lowered the solubility and the initial and final setting times. The addition of AgNPs to PC/ZrO2 maintained the pH, lowered the solubility, and increased the setting time and compressive strength. The radiopacity of all materials was higher than 4 mmAl. The addition of AgNPs promoted an increase in antibacterial activity for calcium silicate cements and favored the physicochemical and mechanical properties of the materials.

Push-out Bond Strength of Root-end Filling Materials

The aim of this study was to evaluate the bond strength of root-end filling materials. Forty 2-mm-thick slices were obtained from human single-rooted teeth. After root canal preparation using a 1.5 mm diameter cylindrical drill, the dentinal walls were prepared by diamond ultrasonic tip (CVD T0F-2). The specimens were divided according the material (n=10): MTA Angelus (MTAA), MTA Sealer (MTAS, experimental), Sealer 26 (S26) and zinc oxide and eugenol cement (ZOE). The push-out test was performed in a mechanical test machine (EMIC DL 2000) at 1 mm/min speed. The failure type was evaluated by stereomicroscopy. The results were subjected to ANOVA and Tukey test, at 5% significance level. MTAA (19.18 MPa), MTAS (19.13 MPa) and S26 (15.91 MPa) showed higher bond strength (p<0.05). ZOE (9.50 MPa) showed the least bond strength values (p<0.05). Adhesive failure was prevalent in all groups, except for ZOE, which showed mixed failures. It was concluded that root-end filling materials MTA Angelus, MTA Sealer and Sealer 26 showed higher bond strength to dentinal walls than zinc oxide and eugenol cement after retrograde preparation.

Promotion of Dental Pulp Cell Migration and Pulp Repair by a Bioceramic Putty Involving FGFR-mediated Signaling Pathways

Mineral trioxide aggregate is the currently recommended material of choice for clinical pulp repair despite several disadvantages, including handling inconvenience. Little is known about the signaling mechanisms involved in bioceramic-mediated dental pulp repair-particularly, dental pulp cell (DPC) migration. This study evaluated the effects of iRoot BP Plus, a novel ready-to-use nanoparticulate bioceramic putty, on DPC migration in vitro and pulp repair in vivo, focusing on possible involvement of fibroblast growth factor receptor (FGFR)-related signaling, including mitogen-activated protein kinase and Akt pathways. Treatment with iRoot BP Plus extracts enhanced horizontal and vertical migration of DPCs, which was comparable with the effects induced by mineral trioxide aggregate extracts. The DPCs exposed to iRoot BP Plus extracts demonstrated no evident apoptosis. Importantly, treatment with iRoot BP Plus extracts resulted in rapid activation of FGFR, p38 mitogen-activated protein kinase, extracellular signal-regulated kinase (ERK) 1/2, c-Jun-N-terminal kinase (JNK), and Akt signaling in DPCs. Confocal immunofluorescence staining revealed that iRoot BP Plus stimulated focal adhesion formation and stress fiber assembly in DPCs, in addition to upregulating the expression of focal adhesion molecules, including p-focal adhesion kinase, p-paxillin, and vinculin. Moreover, activation of FGFR, ERK, JNK, and Akt were found to mediate the upregulated expression of focal adhesion molecules, stress fiber assembly, and enhanced DPC migration induced by iRoot BP Plus. Consistent with the in vitro results, we observed induction of homogeneous dentin bridge formation and expression of p-focal adhesion kinase, p-FGFR, p-ERK 1/2, p-JNK, and p-Akt near injury sites by iRoot BP Plus in an in vivo pulp repair model. These data demonstrate that iRoot BP Plus can promote DPC migration and pulp repair involving the FGFR-mediated ERK 1/2, JNK, and Akt pathways. These findings provide valuable insights into the signaling mechanisms underlying nanoparticulate bioceramic-mediated pulp repair.

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.