Histological evaluation of tissue reaction and new bone formation of different calcium silicate-based cements in rats

BACKGROUND

The purpose of this study was to evaluate the local reactions and new bone formation of rat subcutaneous and bone tissue to different calcium silicate cements.

METHODS

In this study, 80 rats were divided into five groups as control, BIOfactor MTA (BIO), NeoMTA Plus (NEO), MTA Repair Hp (REP), Biodentine (DENT) and then into two subgroups according to sacrification times (7, 30 days; n = 8). Polyethylene tubes filled with appropriate materials (test groups); empty tubes (control group) were implanted into the dorsum of each rat subcutaneously. For intraosseous implantation, materials were placed in the cavities created in tibia of rats. Subcutaneous tissue and tibia samples were stained with haematoxylin-eosin and subjected to histopathological analysis. A score (0-3) was used to grade inflammatory reaction and new bone formation. Data were analysed by Kruskal-Wallis and Mann-Whitney U tests (P < 0.05).

RESULTS

Inflammatory reaction observed in subcutaneous and intraosseous tissues for 7 days decreased significantly in all groups over time (P < 0.05). It was determined that there was significant increase in new bone formation in REP, BIO, DENT groups over time (P < 0.05).

CONCLUSION

Four contemporary bioceramic materials induced local inflammation and tissues changes shortly after subcutaneous implantation, which were reduced over time. In ıntraosseous implantation, all materials induced new bone formation over time.

REGISTRATION NUMBER

ADJ-03-23-0134. © 2023 Australian Dental Association.

Prevention efficacy of dentin tubule sealing with Nd:YAG laser against tooth discoloration induced by vital pulp treatment

BACKGROUND

The discoloration potential of dental materials and applications such as vital pulp therapy also cause discoloration due to the presence of blood. Dentin tubule sealing methods could be used for the prevention of discoloration.

AIM

The purpose of this study was to evaluate the effect of sealing pulp chamber walls with Nd:YAG laser against discoloration caused by tricalcium silicate-based materials in the presence and absence of blood contamination.

DESIGN

Eighty-one extracted human maxillary incisors were prepared and randomly divided into nine groups according to the Nd:YAG laser application, the cement to be used (NeoMTA Plus/Biodentine), and the presence or absence of blood. The color measurements were obtained with a spectrophotometer at baseline and then at the sixth (T1) and 12th (T2) months thereafter.

RESULTS

Sealing with Nd:YAG laser and placing NeoMTA Plus or Biodentine on human blood significantly increased discoloration at T1 and T2 (p < .05). Similarly, without sealing the cavity and placing NeoMTA Plus or Biodentine on human blood significantly increased discoloration at T1 and T2 (p < .05).

CONCLUSION

Regardless of sealing the dentin tubules with Nd:YAG laser, NeoMTA Plus and Biodentine caused more discoloration in the presence of blood contamination.

Osteogenic differentiation and proliferation of apical papilla stem cells using nanoparticles of Neo MTA and bioactive glass

Objective

The aim of this study was to evaluate the osteogenic differentiation ability and proliferation of apical papilla stem cells using nanoparticles of Neo MTA and bioactive glass.

Methods

Neo MTA and bioactive glass 45S5 nanoparticles were prepared and characterized using a transmission electron microscope and X-ray diffraction. Apical papilla stem cells were harvested from freshly-extracted fully-impacted wisdom teeth, cultured, and characterized using flow cytometric analysis. Tested nanomaterials were mixed and samples were classified into four equal groups as follows; Negative control group: SCAP with Dulbecco's modified eagle's medium, Positive control group: SCAP with inductive media, First experimental group: Neo MTA nanoparticles with SCAP, Second experimental group: Bioactive glass nanoparticles with SCAP. Osteoblastic differentiation was assessed using an alkaline phosphatase assay and RANKL expression using specific polyclonal antibodies by fluorescence microscope. The proliferation of SCAP was assessed using cell count and viability of Trypan Blue in addition to an MTT assay.

Results

Isolated SCAP showed a non-hematopoietic origin. Neo MTA showed the highest ALP concentration followed by bioactive glass nanoparticles, and negative control. Bioactive glass nanoparticles showed the highest H score for RANKL protein expression followed by Neo MTA, and negative control. Bioactive glass nanoparticles showed the highest viable cell count.

Conclusions

SCAP isolation is achievable from extracted fully impacted immature third molars. Both tested nanobiomaterials have the ability to induce osteogenic differentiation and proliferation of SCAP.

Interfacial adaptation of NeoMTA Plus, BioRoot RCS and MTA in root-end cavities: A micro-CT study

AIM

This study aimed to use the micro-computed tomography to evaluate the interfacial adaptation and the presence of gaps of NeoMTA Plus, BioRoot RCS, and MTA in the root-end cavities.

METHODOLOGY

Thirty standardized bovine roots measuring 15 mm in length were selected. Chemical-mechanical preparation was performed up to instrument #80 and obturation with the cold lateral compaction technique with cement based on zinc oxide and eugenol. The roots were kept at 37°C for 7 days. Afterward, apicectomy of the apical 3 mm and a root-end filling cavity was performed at 3 mm depth. Micro-computed tomography (micro-CT) was performed to measure the volume of the retroactivity. The roots were divided by stratified randomization into three groups according to the retro-end filling material: NeoMTA Plus, BioRoot RCS, and MTA. A new micro-CT was performed to assess the presence of voids in the root-end filling material and between it and the canal wall. One-way ANOVA and Tukey tests were performed using the BioEstat 4.0 program.

RESULTS

There was no difference in the initial volume values of the root-end cavities (p > .05). After the insertion of root-end filling materials, the most significant volumes of voids were observed in the NeoMTA Plus group (p < .05), with no difference for the BioRoot RCS and MTA Angelus groups (p > .05).

CONCLUSION

Micro-computed tomography showed that MTA and BioRoot RCS have better interfacial adaptation and presented fewer number of gaps than NeoMTA Plus when used as root-end filling materials.

RESEARCH HIGHLIGHTS

Micro-computed tomography evaluation of different root-end fillings materials.

Sol-Gel Technologies to Obtain Advanced Bioceramics for Dental Therapeutics

The aim of this work is to review the application of bioceramic materials in the context of current regenerative dentistry therapies, focusing on the latest advances in the synthesis of advanced materials using the sol-gel methodology. Chemical synthesis, processing and therapeutic possibilities are discussed in a structured way, according to the three main types of ceramic materials used in regenerative dentistry: bioactive glasses and glass ceramics, calcium phosphates and calcium silicates. The morphology and chemical composition of these bioceramics play a crucial role in their biological properties and effectiveness in dental therapeutics. The goal is to understand their chemical, surface, mechanical and biological properties better and develop strategies to control their pore structure, shape, size and compositions. Over the past decades, bioceramic materials have provided excellent results in a wide variety of clinical applications related to hard tissue repair and regeneration. Characteristics, such as their similarity to the chemical composition of the mineral phase of bones and teeth, as well as the possibilities offered by the advances in nanotechnology, are driving the development of new biomimetic materials that are required in regenerative dentistry. The sol-gel technique is a method for producing synthetic bioceramics with high purity and homogeneity at the molecular scale and to control the surfaces, interfaces and porosity at the nanometric scale. The intrinsic nanoporosity of materials produced by the sol-gel technique correlates with the high specific surface area, reactivity and bioactivity of advanced bioceramics.

Clinical outcomes of non-surgical root canal obturations using NeoMTA: A retrospective series of case reports

NeoMTA is a commercially available tricalcium silicate-based cement intended for contact with pulp and periradicular tissues. The purpose of this study was to retrospectively evaluate the outcomes of non-surgical root canal treatments with NeoMTA obturations. Patients were treated in a private endodontic practice between 2015 and 2018. All cases, including initial treatments and retreatments, were either fully obturated with NeoMTA, or using gutta-percha with NeoMTA as an endodontic sealer. Outcomes were assessed using follow-up examination data with digital periapical radiographs with a minimum of a 1-year recall. Teeth were classified based on the clinical examination as: healed/healing (success), or non-healed (failure). 265 teeth were included with an average follow-up time of 1.3 years. The overall success rate was 91.7%. Only the presence of a pre-operative periapical radiolucency was found to significantly affect success. Comparison of obturation techniques demonstrated no effect on outcomes. NeoMTA is suitable for endodontic obturation.

In Vivo Assessment of the Apatite-Forming Ability of New-Generation Hydraulic Calcium Silicate Cements Using a Rat Subcutaneous Implantation Model

Hydroxyapatite formation on endodontic hydraulic calcium silicate cements (HCSCs) plays a significant role in sealing the root canal system and elevating the hard-tissue inductivity of the materials. This study evaluated the in vivo apatite-forming ability of 13 new-generation HCSCs using an original HCSC (white ProRoot MTA: PR) as a positive control. The HCSCs were loaded into polytetrafluoroethylene tubes and implanted in the subcutaneous tissue of 4-week-old male Wistar rats. At 28 days after implantation, hydroxyapatite formation on the HCSC implants was assessed with micro-Raman spectroscopy, surface ultrastructural and elemental characterization, and elemental mapping of the material-tissue interface. Seven new-generation HCSCs and PR had a Raman band for hydroxyapatite (v1 PO₄^3- band at 960 cm^-1) and hydroxyapatite-like calcium-phosphorus-rich spherical precipitates on the surfaces. The other six HCSCs with neither the hydroxyapatite Raman band nor hydroxyapatite-like spherical precipitates did not show calcium-phosphorus-rich hydroxyapatite-layer-like regions in the elemental mapping. These results indicated that 6 of the 13 new-generation HCSCs possessed little or no ability to produce hydroxyapatite in vivo, unlike PR. The weak in vivo apatite-forming ability of the six HCSCs may have a negative impact on their clinical performance.

In Vivo Assessment of the Calcium Salt-Forming Ability of a New Calcium Silicate-Based Intracanal Medicament: Bio-C Temp

Calcium salt precipitation induced by intracanal medicaments contributes to the formation of apical hard tissue during apexification. This study compared the calcium salt-forming ability of a new calcium silicate-based intracanal medicament (Bio-C Temp) with that of two commercial calcium hydroxide pastes (Calcipex Plane II and Vitapex) in a rat subcutaneous implantation model. Polytetrafluoroethylene tubes containing each of the three materials were subcutaneously implanted in 4-week-old male Wistar rats. After 28 days, the composition and amount of calcium salts formed at the material–tissue interface were assessed using micro-Raman spectroscopy, X-ray diffraction, and elemental mapping. The tested materials produced white precipitates that had Raman spectra with peaks corresponding to hydroxyapatite and calcite. X-ray diffraction detected hydroxyapatite formation on Calcipex Plane II and Vitapex implants, as well as calcite formation on all three materials. Elemental mapping revealed that Bio-C Temp generated significantly smaller calcium- and phosphorus-rich calcified regions within the subcutaneous connective tissue than Vitapex. These results indicate that Bio-C Temp produced less calcium salt in rat subcutaneous tissue than Vitapex, although all materials formed hydroxyapatite and calcite in rat subcutaneous tissue. Bio-C Temp could be less effective than Vitapex in promoting apical hard tissue formation during apexification.

Physicochemical, Pre-Clinical, and Biological Evaluation of Viscosity Optimized Sodium Iodide-Incorporated Paste

This study aimed to investigate the impact of different viscosities of silicone oil on the physicochemical, pre-clinical usability, and biological properties of a sodium iodide paste. Six different paste groups were created by mixing therapeutic molecules, sodium iodide (D30) and iodoform (I30), with calcium hydroxide and one of the three different viscosities of silicone oil (high (H), medium (M), and low (L)). The study evaluated the performance of these groups, including I30H, I30M, I30L, D30H, D30M, and D30L, using multiple parameters such as flow, film thickness, pH, viscosity, and injectability, with statistical analysis (p < 0.05). Remarkably, the D30L group demonstrated superior outcomes compared to the conventional iodoform counterpart, including a significant reduction in osteoclast formation, as examined through TRAP, c-FOS, NFATc1, and Cathepsin K (p < 0.05). Additionally, mRNA sequencing showed that the I30L group exhibited increased expression of inflammatory genes with upregulated cytokines compared to the D30L group. These findings suggest that the optimized viscosity of the sodium iodide paste (D30L) may lead to clinically favorable outcomes, such as slower root resorption, when used in primary teeth. Overall, the results of this study suggest that the D30L group shows the most satisfactory outcomes, which may be a promising root-filling material that could replace conventional iodoform-based pastes.

The Use of Premixed Calcium Silicate Bioceramic Sealer with Warm Carrier-Based Technique: A 2-Year Study for Patients Treated in a Master Program

Background: Recently several calcium silicate flowable sealers have been introduced as endodontic materials for the root canal. This clinical study tested the use of a new premixed calcium silicate bioceramic sealer in association with the Thermafil warm carrier-based technique (TF). Epoxy-resin-based sealer with the warm carrier-based technique was the control group. Methodology: Healthy consecutive patients (n = 85) requiring 94 root canal treatments were enrolled in this study and assigned to one filling group (Ceraseal-TF n = 47, AH Plus-TF n = 47) in accordance with operator training and best clinical practice. Periapical X-rays were taken preoperatively, after root canal filling and after 6, 12 and 24 months. Two evaluators blindly assessed the periapical index (PAI) and sealer extrusion in the groups (k = 0.90). Healing rate and survival rate were also evaluated. Chi-square tests was used to analyze significant differences between the groups. Multilevel analysis was performed to evaluate the factors associated with healing status. Results: A total of 89 root canal treatments in 82 patients were analyzed at the end-line (24 months). The total drop-out was 3.6% (3 patients; 5 teeth). A total of 91.1% of healed teeth (PAI 1-2) was observed in Ceraseal-TF, with 88.6% in AH Plus-TF. No significant difference was observed on healing outcome and survival among the two filling groups (p > 0.05). Apical extrusion of the sealers occurred in 17 cases (19.0%). Of these, 6 occurred in Ceraseal-TF (13.3%) and 11 in AH Plus-TF (25.0%). Three Ceraseal extrusions were radiographically undetectable after 24 months. All the AH Plus extrusions did not change during the evaluation time. Conclusions: The combined use of the carrier-based technique and premixed CaSi-based bioceramic sealer showed clinical results comparable with carrier-based technique and epoxy-resin-based sealer. The radiographical disappearance of apically extruded Ceraseal is a possible event in the first 24 months.

Comparison of fracture resistance of simulated immature teeth using four different commercially available apexification materials - An in vitro study

Introduction

The aim of this study was to compare the fracture resistance of simulated immature teeth using four different apical plug materials, i.e. Pro- Root MTA, Neo- MTA Plus, Biodentine, and Bioactive Glass.

Materials and Methods

80 extracted human maxillary anterior teeth were divided into 4 groups for this study. They were prepared using Peeso reamers to simulate immature teeth and to mimic Cvek's stage 3 of root development. A 5 mm apical barrier was placed using different materials. The remaining canal was obturated using gutta-percha and AH plus sealer. The final samples were stored at 37°C and 100% humidity for 4 weeks. Fracture resistance of the teeth was measured in Newtons using a universal testing machine. The comparison of fracture resistance between the four groups was done using Kruskal Walis ANOVA followed by post hoc Mann Whitney U test for pairwise comparison.

Results

Biodentine group showed the highest fracture resistance as compared to the other three groups and the difference was highly significant (P < 0.001).

Conclusions

Biodentine can be advocated over MTA as an effective material for the management of teeth with wide open apex. Bioactive glass also has shown promising results in increasing the fracture resistance of simulated immature teeth.

Dental and composite resin discoloration induced by different hydraulic calcium silicate-based cements: two-year in vitro assessment

Few long-term studies assess the discoloration induced by hydraulic calcium silicate-based cement on dental structures. In addition, as far as we know, no long-term study has assessed the discoloration induced by these cement on composite resin. This in vitro study aimed to assess, during a period of two years, the discoloration potential of different hydraulic calcium silicate-based cements (hCSCs) on the enamel/dentin structure and composite resin restoration. A total of 40 enamel/dentin discs were obtained from bovine incisors, and 40 composite resin discs (10 mm in diameter × 2 mm thick) were fabricated. A 0.8 mm-deep cavity was made in the center of each disc and filled with the following hCSCs (n=10): Original MTA (Angelus); MTA Repair HP (Angelus); NeoMTA Plus (Avalon); and Biodentine (Septodont). An initial color measurement was performed (T0 - baseline). After 7, 15, 30, 45, 90, 300 days, and two years, new color measurements were performed to determine the color (ΔE00), lightness (ΔL'), chroma (ΔC'), hue differences (ΔH'), and whiteness index (WID). For enamel/dentin, the ΔE00 was significant among groups and periods (p<0.05). NeoMTA Plus had the greatest ΔE00. The NeoMTA Plus group had the greatest ΔE00 after two years for composite resin. Significant reduction in lightness was observed for all groups after two years (p<0.05). The most significant WID values were observed after 30 days for Biodentine (enamel/dentin) and MTA Repair HP groups (composite resin) (p<0.05). The hCSCs changed the colorimetric behavior of both substrates, leading to greater darkening over time. The Bi2O3 in the Original MTA seems relevant in the short periods of color change assessment.

Characterisation of the calcium silicate-based cement-composite interface and the bonding strength with total-etch or single/two-stage self-etch adhesive systems

Due to favourable biological and physical properties, calcium silicate-based cements (CSCs) are biocompatible materials used widely for vital pulp therapies. Sealing efficacy between the adhesive system and CSC determines the clinical success of treatment. This study aimed to evaluate the shear bond strength (SBS) of CSC to composite resin with different adhesive systems and to analyse the CSC-composite interface. Mineral trioxide aggregate (MTA) (ProRoot MTA; Dentsply Tulsa Dental, Tulsa, OK), Biodentine (Septodont, Saint-Maur-des-Fossés, France) and NeoMTA Plus (Avalon Biomed Inc., Bradenton, FL) samples (n = 90) were placed in the cavities and divided into three subgroups according to the adhesive family (n = 10). SBSs were measured using a universal testing machine. The interfaces were examined using a scanning electron microscope (SEM) (×1000). NeoMTA Plus showed significantly higher SBS values than MTA and Biodentine (P < 0.0001). The application of total-etch adhesive system over Biodentine and NeoMTA Plus provided the statistically highest bond strength (P < 0.05). However, when the SBS values of MTA subgroups were compared, different adhesive families applied over MTA did not make a significant difference in SBS values (P > 0.05). Based on SEM analyses, the specimens exhibit no gaps, cracks or delamination within the adhesive layer, which indicates a good adhesion between the CSC-composite interface in all subgroups. In conclusion, the different adhesive families used over CSC did not influence interfacial gap formation.

Chemical-Physical Properties and Bioactivity of New Premixed Calcium Silicate-Bioceramic Root Canal Sealers

The aim of the study was to analyze the chemical−physical properties and bioactivity (apatite-forming ability) of three recently introduced premixed bioceramic root canal sealers containing varied amounts of different calcium silicates (CaSi): a dicalcium and tricalcium silicate (1−10% and 20−30%)-containing sealer with zirconium dioxide and tricalcium aluminate (CERASEAL); a tricalcium silicate (5−15%)-containing sealer with zirconium dioxide, dimethyl sulfoxide and lithium carbonate (AH PLUS BIOCERAMIC) and a dicalcium and tricalcium silicate (10% and 25%)-containing sealer with calcium aluminate, tricalcium aluminate and tantalite (NEOSEALER FLO). An epoxy resin-based sealer (AH PLUS) was used as control. The initial and final setting times, radiopacity, flowability, film thickness, open pore volume, water absorption, solubility, calcium release and alkalizing activity were tested. The nucleation of calcium phosphates and/or apatite after 28 days aging in Hanks balanced salt solution (HBSS) was evaluated by ESEM-EDX, vibrational IR and micro-Raman spectroscopy. The analyses showed for NeoSealer Flo and AH Plus the longest final setting times (1344 ± 60 and 1300 ± 60 min, respectively), while shorter times for AH Plus Bioceramic and Ceraseal (660 ± 60 and 720 ± 60 min, respectively). Radiopacity, flowability and film thickness complied with ISO 6876/12 for all tested materials. A significantly higher open pore volume was observed for NeoSealer Flo, AH Plus Bioceramic and Ceraseal when compared to AH Plus (p < 0.05), significantly higher values were observed for NeoSealer Flo and AH Plus Bioceramic (p < 0.05). Ceraseal and AH Plus revealed the lowest solubility. All CaSi-containing sealers released calcium and alkalized the soaking water. After 28 days immersion in HBSS, ESEM-EDX analyses revealed the formation of a mineral layer that covered the surface of all bioceramic sealers, with a lower detection of radiopacifiers (Zirconium for Ceraseal and AH Plus Bioceramic, Tantalum for NeoSealer Flo) and an increase in calcium, phosphorous and carbon. The calcium phosphate (CaP) layer was more evident on NeoSealer Flo and AH Plus Bioceramic. IR and micro-Raman revealed the formation of calcium carbonate on the surface of all set materials. A thin layer of a CaP phase was detected only on AH Plus Bioceramic and NeoSealer Flo. Ceraseal did not show CaP deposit despite its highest calcium release among all the tested CaSi-containing sealers. In conclusion, CaSi-containing sealers met the required chemical and physical standards and released biologically relevant ions. Slight/limited apatite nucleation was observed in relation to the high carbonation processes.

Alkalizing Properties of Six Calcium-Silicate Endodontic Biomaterials

INTRODUCTION

Calcium silicate-based cements (CSC), are self-setting hydraulic biomaterials widely used for reparative procedures in dentistry and endodontics. These materials possess physical properties, such as ion release, porosity, solubility, and radiopacity. Their biological properties are connected to their alkalizing activity and calcium release capacity.

MATERIALS AND METHODS

Six calcium silicate-based materials were selected for this study: TheraCal LC (Bisco Inc., Schaumburg, IL, USA), MTA Plus (PrevestDenpro, Jammu, India Avalon Biomed Inc., Bradenton, FL, USA), Biodentine (Septodont, Saint-Maur-des-Fossés, France), RetroMTA (BioMTA, Seoul, Korea), MTA Flow (Ultradent Products, Inc., South Jordan, UT, USA), and OrthoMTA (BioMTA, Seoul, Korea). The pH was analyzed immediately after immersion (baseline) and after 1 h, 3 h, 1 day, 2 days, 3 days, 1 week, 2 weeks, 3 weeks, and 1 year with a pH meter, previously calibrated with solutions of known pH. All testing materials had alkaline pH.

RESULTS

Analysis of the tested materials showed statistically significant differences in terms of pH changes as a function of the time showed a gradual rise in the pH of all materials.

CONCLUSIONS

All tested materials exhibited continuous hydroxyl ion release resulting in a rise in pH until the end of time of experience.

Influence of acidic pH on antimicrobial activity of different calcium silicate based-endodontic sealers

OBJECTIVE

To investigate the antibacterial activity of calcium silicate-based sealers (CSBSs) against Enterococcus faecalis biofilm in a neutral or acidic condition.

MATERIALS AND METHODS

Dentin cylinders (4 mm length) were prepared and infected with 3-week-old E. faecalis. The samples were filled with BioRoot RCS (BR), EndoSequence BC (ES), and NeoMTA Plus (NMTA) and incubated in either neutral or acidic conditions for 7 days (n=10/group). Sterile or infected samples alone were used as the positive and negative control. The root canal sealers were removed after 7 days, and the remaining bacteria on dentinal walls were determined by colony-forming units (CFUs/ml), and three samples from each group were visualized under a confocal laser scanning microscope (CLSM). The pH was also measured (n=3/group) after 4 h and 7 days of incubation at 37°C in both conditions.

RESULTS

In the neutral condition, all sealers significantly decreased the log-CFU values (p<0.05), while in the acidic condition, the log-CFU reduction was less for ES and NMTA, but a higher reduction was observed in BR (p<0.05). The antibacterial activity of CSBSs was similar in neutral conditions (p>0.05), and BR showed a greater antibacterial effect than ES and NMTA in the acidic condition (p<0.05). The pH of BR, ES, and NMTA ranged from 8.2 to 8.8 in the neutral condition in the presence of dentin after 7 days. However, acidic conditions reduced the pH values to 7.8 for BR, 6.0 for ES, and 5.8 for NMTA.

CONCLUSIONS

All CSBSs showed similar antibacterial activity in neutral conditions, while acidic pH had a reducing antibacterial effect on CSBSs.

CLINICAL RELEVANCE

Inflammatory pH decreased the antibacterial properties of CSBSs depending on the sealer type.

Green Hydrogels Composed of Sodium Mannuronate/Guluronate, Gelatin and Biointeractive Calcium Silicates/Dicalcium Phosphate Dihydrate Designed for Oral Bone Defects Regeneration

Innovative green, eco-friendly, and biologically derived hydrogels for non-load bearing bone sites were conceived and produced. Natural polysaccharides (copolymers of sodium D-mannuronate and L-guluronate) with natural polypeptides (gelatin) and bioactive mineral fillers (calcium silicates CaSi and dicalcium phosphate dihydrate DCPD) were used to obtain eco-sustainable biomaterials for oral bone defects. Three PP-x:y formulations were prepared (PP-16:16, PP-33:22, and PP-31:31), where PP represents the polysaccharide/polypeptide matrix and x and y represent the weight % of CaSi and DCPD, respectively. Hydrogels were tested for their chemical-physical properties (calcium release and alkalizing activity in deionized water, porosity, solubility, water sorption, radiopacity), surface microchemistry and micromorphology, apatite nucleation in HBSS by ESEM-EDX, FT-Raman, and micro-Raman spectroscopies. The expression of vascular (CD31) and osteogenic (alkaline phosphatase ALP and osteocalcin OCN) markers by mesenchymal stem cells (MSCs) derived from human vascular walls, cultured in direct contact with hydrogels or with 10% of extracts was analysed. All mineral-filled hydrogels, in particular PP-31:31 and PP-33:22, released Calcium ions and alkalized the soaking water for three days. Calcium ion leakage was high at all the endpoints (3 h-28 d), while pH values were high at 3 h-3 d and then significantly decreased after seven days (p < 0.05). Porosity, solubility, and water sorption were higher for PP-31:31 (p < 0.05). The ESEM of fresh samples showed a compact structure with a few pores containing small mineral granules agglomerated in some areas (size 5-20 microns). PP-CTRL degraded after 1-2 weeks in HBSS. EDX spectroscopy revealed constitutional compounds and elements of the hydrogel (C, O, N, and S) and of the mineral powders (Ca, Si and P). After 28 days in HBSS, the mineral-filled hydrogels revealed a more porous structure, partially covered with a thicker mineral layer on PP-31:31. EDX analyses of the mineral coating showed Ca and P, and Raman revealed the presence of B-type carbonated apatite and calcite. MSCs cultured in contact with mineral-filled hydrogels revealed the expression of genes related to vascular (CD31) and osteogenic (mainly OCN) differentiation. Lower gene expression was found when cells were cultured with extracts added to the culture medium. The incorporation of biointeractive mineral powders in a green bio-derived algae-based matrix allowed to produce bioactive porous hydrogels able to release biologically relevant ions and create a suitable micro-environment for stem cells, resulting in interesting materials for bone regeneration and healing in oral bone defects.

Evaluation of the Physicochemical and Biological Properties of EndoSequence BC Sealer HiFlow

INTRODUCTION

Understanding the physicochemical and biological properties of endodontic sealers is important for endodontic treatment planning. This study evaluated the properties of EndoSequence BC Sealer HiFlow (BCH; Brasseler USA, Savannah, GA), EndoSequence BC Sealer (BC, Brasseler USA), and AH Plus (AHP; Dentsply DeTrey, Konstanz, Germany). The effect of temperature on the setting time and flow of these sealers was also evaluated.

METHODS

The setting time, flow, radiopacity, pH, solubility, and calcium release were investigated following ISO guidelines. The morphology and chemical composition of the sealers were evaluated by scanning electron microscopy and energy-dispersive spectroscopy. The antibacterial activity of sealers was tested against 2 strains of Enterococcus faecalis. Sealer cytotoxicity and the effects on messenger RNA expression of proinflammatory and mineralization genes were also investigated. Data analysis was performed using analysis of variance, Tukey, Kruskal-Wallis, and Dunn multiple comparison tests. P ≤ .05 was considered statistically significant.

RESULTS

The setting time and flow rate of all sealers were affected by heat (P ≤ .05). The setting times and solubility of BCH and BC were significantly higher than AHP (P ≤ .0001). The radiopacity of AHP was higher than BCH and BC (P ≤ .0001). All sealers were alkaline and had antibacterial effects. Cell viability was higher for BCH and BC than AHP (P ≤ .0001). No significant differences in messenger RNA expression of proinflammatory and mineralization genes were observed.

CONCLUSIONS

Overall, BCH and BC had similar physicochemical and biological properties. The observed high solubility of BCH and BC as well as the high cytotoxicity of AHP might negatively impact the clinical performance of these materials. The application of heat affected the setting time and flow of all sealers.

Pulpal response to mineral trioxide aggregate containing phosphorylated pullulan-based capping material

This study aimed to evaluate the pulpal responses of monkey's pulp after direct pulp capping (DPC) with the novel mineral trioxide aggregate containing phosphorylated pullulan-based material (MTAPPL). Seventy-two teeth were randomly divided into four groups: MTAPPL; Nex-Cem MTA (NX); TheraCal LC (TH); and Dycal (DY). Histopathological changes in the pulps were observed at days 3, 7 and 70. On day 3, mild inflammatory responses were observed in the MTAPPL, no to moderate inflammatory responses in the TH, whereas moderate inflammatory responses in the NX and DY. No mineralized tissue formation (MTF) was observed in all groups. On day 7, no or mild inflammatory responses were observed in all groups. Initial MTF was observed except for DY. No inflammation with complete MTF including presence of odontoblast-like cells was observed in the MTAPPL, NX and TH groups at day 70. These findings indicate that MTAPPL could be an efficient DPC material.

Evaluation of the Interfaces between Restorative and Regenerative Biomaterials Used in Vital Pulp Therapy

BACKGROUND

Calcium-silicate-based cements (CSC) have gained an increasing scientific and clinical relevance, enabling more conservative approaches, namely pulp preservation and regeneration therapies. This research aims to study the influence of four clinical variables on the interfaces between CSC and composite adhesive restoration, concerning shear bond strength (SBS) and ultra-morphological patterns.

METHODS

SBS tests were performed in 320 specimens divided in 16 groups (n = 20) according to: two CSC (NuSmile^® NeoMTA, Biodentine^TM); two adhesive systems (Clearfil^TM SE Bond 2 (CSEB2), Clearfil^TM Universal Bond Quick (CUBQ)); optional application of an additional hydrophobic bonding layer (HBL); two restoration times (immediate, seven days). Scanning electron microscopy (SEM) was performed to conduct the ultra-morphology interface analysis in 32 deciduous molars prepared and randomly allocated into the 16 groups.

RESULTS

Globally, SBS tests showed higher bond strength of CUBQ compared to CSEB2 (p < 0.001), as with an additional HBL application (p = 0.014) and delayed restoration (p < 0.001). SEM showed the interpenetration between adhesive systems and CSC forming a hybrid layer, whose depth and thickness depended on the restoration time and adhesive strategy.

CONCLUSIONS

The independent clinical variables adhesive system, application of an additional HBL and restoration time affected the bond performance and ultra-morphological interface between composite adhesive restoration and CSC.

Histological evaluation of a novel phosphorylated pullulan-based pulp capping material: An in vivo study on rat molars

AIM

To evaluate the dental pulp response to a novel mineral trioxide aggregate containing phosphorylated pullulan (MTAPPL) in rats after direct pulp capping.

METHODS

Ninety-six cavities were prepared in the maxillary first molars of 56 male Wistar rats. The dental pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials: MTAPPL; phosphorylated pullulan (PPL); a conventional MTA (Nex-Cem MTA, NCMTA; positive control); and Super-Bond (SB; negative control). All cavities were restored with SB and observed for pulpal responses at 1-, 3-, 7- and 28-day intervals using a histological scoring system. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-test with Bonferroni's correction, and the level of significance was set at 0.05. DMP1 and CD34 antigen were used to evaluate odontoblast differentiation and pulpal vascularization, respectively.

RESULTS

On day 1, mild inflammatory cells were present in MTAPPL and NCMTA groups; fewer inflammatory cells were present in the PPL, whereas SB was associated with a mild-to-moderate inflammatory response. A significant difference was observed between PPL and SB (p < .05). No mineralized tissue deposition was observed. On day 3, moderate-to-severe inflammatory cells were present in PPL and SB, whereas MTAPPL and NCMTA had a mild inflammatory response. Initial mineralized tissue deposition was observed in the NCMTA, MTAPPL and SB. A significant difference was observed between MTAPPL and PPL (p < .05). On day 7, a thin layer of mineralized tissue was observed in all tested groups with no or mild inflammatory response. On day 28, no inflammatory response was observed in MTAPPL, whereas NCMTA, PPL and SB had mild inflammatory responses. A significant difference was observed between MTAPPL and SB (p < .05). Complete mineralized tissue barrier formation was observed in MTAPPL, NCMTA and PPL with no significant difference (p > .05). SB exhibited incomplete mineralized tissue barriers, significantly different from NCMTA, MTAPPL and PPL (p < .05). The staining with CD34 was positive in all the groups on all observation days.

CONCLUSION

The favourable pulpal responses and induction of mineralized tissue formation associated with MTAPPL indicate its potential application as a direct pulp capping material.

Biocompatibility of NeoMTA Plus® versus MTA Angelus as delayed furcation perforation repair materials in a dog model

BACKGROUND

The biocompatibility of NeoMTA Plus® (Avlon BioMed Inc., Bradenton, Fl) as a furcal perforation repair material is not fully understood. This study compares the biocompatibility of Mineral Trioxide Aggregate (MTA Angelus) and NeoMTA Plus® as delayed furcation perforation repair materials.

METHODS

Pulpotomy and root canal obturation were performed in 72 premolars in six mongrel dogs and then a standardized furcal perforation was performed. The coronal access was left open for three weeks. After curetting, cleaning and drying of the perforations, these teeth were divided into three equal groups (N = 24 teeth/ 2 dogs each) according to the material used for perforation repair; group I: NeoMTA Plus®, group II: MTA Angelus and group III: no material (positive control). The coronal access cavities were sealed with a filling material. The inflammatory cell count and qualitative pathology (presence of calcific bridge, configuration of fibrous tissue formed, examination of tissue surrounding the furcation area, histology of intraradicular bone and the inflammatory nature of tissues) were carried out after one week (subgroup A, N = 8 teeth), one month (subgroup B, N = 8 teeth) and three months (subgroup C, N = 8 teeth). The inflammatory cell count was expressed as mean ± SD and statistically analyzed. P-value < 0.05 was considered significant.

RESULTS

In all subgroups, the control group exhibited the highest number of inflammatory cell count, followed by MTA Angelus group and the least inflammatory cell count was shown by NeoMTA Plus® group. There was a significant difference in the inflammatory cell count between the NeoMTA Plus® and MTA Angelus after one week (P < 0.05) while no significant differences were recorded between them after one month and three months (P > 0.05). In contrast to group II, there was no significant differences in inflammatory cell count between the subgroups in groups I and III (P > 0.05). NeoMTA Plus® exhibited better qualitative pathological features than MTA Angelus after one week and nearly similar features after one month and three months of repair.

CONCLUSION

NeoMTA Plus® has a better early biocompatibility than MTA Angelus after one week of delayed furcation perforation repair and a similar late biocompatibility after one month and three months.

Biocompatibility and bioactive potential of the NeoMTA Plus endodontic bioceramic-based sealer

Objectives

This study evaluated the biocompatibility and bioactive potential of NeoMTA Plus mixed as a root canal sealer in comparison with MTA Fillapex.

Materials and Methods

Polyethylene tubes filled with NeoMTA Plus (n = 20), MTA Fillapex (n = 20), or nothing (control group, CG; n = 20) were inserted into the connective tissue in the dorsal subcutaneous layer of rats. After 7, 15, 30 and 60 days, the specimens were processed for paraffin embedding. The capsule thickness, collagen content, and number of inflammatory cells (ICs) and interleukin-6 (IL-6) immunolabeled cells were measured. von Kossa-positive structures were evaluated and unstained sections were analyzed under polarized light. Two-way analysis of variance was performed, followed by the post hoc Tukey test (p ≤ 0.05).

Results

At 7 days, the capsules around NeoMTA Plus and MTA Fillapex had more ICs and IL-6-immunostained cells than the CG. However, at 60 days, there was no significant difference in the IC number between NeoMTA Plus and the CG (p = 0.1137) or the MTA Fillapex group (p = 0.4062), although a greater number of IL-6-immunostained cells was observed in the MTA Fillapex group (p = 0.0353). From 7 to 60 days, the capsule thickness of the NeoMTA Plus and MTA Fillapex specimens significantly decreased, concomitantly with an increase in the collagen content. The capsules around root canal sealers showed positivity to the von Kossa stain and birefringent structures.

Conclusions

The NeoMTA Plus root canal sealer is biocompatible and exhibits bioactive potential.

Premixed bioceramics versus mineral trioxide aggregate in furcal perforation repair of primary molars: in vitro and in vivo study

OBJECTIVES

The current study was carried out to (1) evaluate premixed bioceramic (BC) and mineral trioxide aggregate (MTA) sealing properties in a laboratory and (2) compare the performance of these two materials in repairing an immediate iatrogenic furcal perforation of primary molars both clinically and radiographically.

MATERIALS AND METHODS

In vitro sections including eighty mandibular second primary molars were sorted into 4 equal groups: (1) an intact furcation area group, (2) an artificial perforation group (unrepaired), (3) an artificial perforation group repaired with MTA, and (4) an artificial perforation group repaired with premixed BC. The dye extraction method was used to assess the sealing ability of the material. Clinically, the study was designed as an equivalent parallel randomized controlled trial. Seventy-six mandibular second primary molars with immediate furcal perforation were sealed with MTA and premixed BC. Teeth were evaluated clinically and radiographically at 3, 6, and 12 months.

RESULTS

Although the difference was statistically insignificant (p = 0.058), the premixed BC group had better sealing ability than the MTA group [mean difference = 0.020; 95% CI (-0.001, 0.040)]. Clinically and radiographically, the two materials had an equivalent success rate in the first 3 months [ARR = 0.05; 95% CI (-0.07, 0.17)] but inequivalent success rates at 6 and 12 months with premixed BC performing better than MTA.

CONCLUSIONS

The present findings confirm that premixed BC is a promising material that can be used to repair a furcal perforation of primary molars. Premixed BC has better sealing properties and better performance at the clinical and radiographic levels than MTA.

CLINICAL RELEVANCE

(1) Accidental furcal perforation in primary molars is one of the worst problems that results in diminishing the lifetime expectancy of primary teeth if not properly treated. Though new BC repair materials have been introduced to enhance healing and tissue inductive properties, there is an obvious shortage in clinical trials covering this area. The present study is a premier study that assesses a recently introduced premixed BC material in the furcal perforation of primary teeth and compares its outcomes with those of the widely used MTA.

TRIAL REGISTRATION

ClinicalTrials.gov PRS reference #NCT04137861.

A Comparative Study of Surface Hardness between Two Bioceramic Materials in an Experimental Apexification Model under Wet and Dry Conditions

Background:

The placement of a wet cotton pellet against Mineral Trioxide Aggregate (MTA) is often recommended to ensure the completion of its setting reaction.

Objective:

This study aimed to evaluate the setting behaviour of MTA Angelus and NeoMTA by comparing their hardness after placing them in dry and moist conditions.

Methodology:

A simulated open apex was created on 40 polyvinyl tubes. The apical 4 mm of the tubes was filled with the two materials, NeoMTA Plus (Avalon Biomed Inc. Bradenton, FL, USA) and MTA Angelus (Angelus, Londrina, PR, Brazil) (n=20 per group). Both groups were subdivided into two subgroups based on the dry and wet conditions (n=10 per group). A wet cotton pellet was placed above the two materials in the wet group, and the coronal segment was sealed using Type II Glass ionomer cement (GC corporation Tokyo, Japan). Gutta-percha was placed against the test materials in the dry group with the coronal segment sealed with amalgam. Samples were placed in an oasis soaked in phosphate-buffered saline for seven days in 100% humidity and at 37°C. Microhardness was measured independently at 4 and 2 mm from the apex. Hardness was compared between materials and conditions, applying analysis of variance (a = .05).

Results:

The presence of dry or wet conditions had no significant effect on material hardness. MTA Angelus showed significantly higher hardness values compared with NeoMTA Plus.

Conclusion:

The moisture of the periapical environment can compensate for the absence of a wet cotton pellet and is adequate for the setting of the materials.

Antifungal Effectiveness between Tricalcium Silicate-White Portland Cements Added Bi2O3 and Mineral Trioxide Aggregate Against Candida albicans

Background

Candida albicans is the most dominant fungus found in root canal reinfection cases. This microorganism can withstand extreme pH, low oxygen levels, lack of nutrients, and penetrate the dentinal tubules so that it can resist the intracanal medicament. Root canal cement helps prevent microorganisms and causing root canal reinfection. MTA is one of the root canals cement which is widely used and has an excellent antifungal activity, but it is less beneficial economically. Tricalcium silicate-white Portland cement (WPC) has a similar main composition as MTA, except there is no Bi2O3 content that functions as a radiopacifier.

Objectives:

To fabricate a mixture of tricalcium silicate-WPC with Bi2O3 through a simple solution method and investigate antifungal activity's effectiveness between tricalcium silicate-WPC added Bi2O3 and MTA to C. albicans.

Materials and Methods:

The 80 g of tricalcium silicate-WPC was mixed with 20 g of Bi2O3 through the simple solution method using 99.9% isopropanol as a solution. This sample solution is stirred until homogeneous, then centrifuged. The precipitate was dried until a dry powder was obtained. The powder was analyzed using X-Ray fluorescence spectrometry to identify its chemical composition and concentration. A total of 30 samples were divided into two experimental groups of tricalcium silicate-WPC added Bi2O3 and ProRoot MTA. The vials, which contain cement and C. albicans, respectively, were incubated at 37°C for 24 hours and diluted to obtain a suspension 104, 106 (0.5 in McFarland’s nephelometer) and then inoculated with sterile cotton swabs onto Saboroud Dextrose Agar Plates. The plates were incubated at 37°C for 24 hours. The measurement of colony number of C. albicans was counted by colony counter (CFU/ml).

Results:

The Bi2O3 was revealed in tricalcium silicate-WPC based on XRF characterization, and the antifungal test showed that both materials were effective against C. albicans. There was no statistically significant difference in the number of C. albicans colonies between tricalcium-WPC added Bi2O3 and MTA (p>0.05).

Conclusion:

The mixture of Bi2O3 in tricalcium silicate-WPC was successfully fabricated through a simple solution method, and both samples were effective against the C. albicans.

The effects of mineral trioxide aggregate on osteo/odontogenic potential of mesenchymal stem cells: a comprehensive and systematic literature review

The significance of dental materials in dentin-pulp complex tissue engineering is undeniable. The mechanical properties and bioactivity of mineral trioxide aggregate (MTA) make it a promising biomaterial for future stem cell-based endodontic therapies. There are numerous in vitro studies suggesting the low cytotoxicity of MTA towards various types of cells. Moreover, it has been shown that MTA can enhance mesenchymal stem cells' (MSCs) osteo/odontogenic ability. According to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), a literature review was conducted in the Medline, PubMed, and Scopus databases. Among the identified records, the cytotoxicity and osteo/odontoblastic potential of MTA or its extract on stem cells were investigated. Previous studies have discovered the differentiation-inducing potential of MTA on MSCs, providing a background for dentin-pulp complex cell therapies using the MTA, however, animal trials are needed before moving into clinical trials. In conclusion, MTA can be a promising candidate dental biomaterial for futuristic stem cell-based endodontic therapies.

Cytotoxicity of NeoMTA Plus, ProRoot MTA and Biodentine on human dental pulp stem cells

Background/purpose

Dental pulp stem cells (DPSCs) play a crucial role in the tissue healing process through odontoblast like cell differentiation. The aim of this study was to evaluate the biocompatibility and compare the potential invitro cytotoxic effects of NeoMTA Plus, ProRootMTA and Biodentine on human dental pulp stem cells (hDPSCs).

Materials and methods

To assess the effects of NeoMTA Plus, ProRoot MTA and Biodentine extracts at 1st, 3rd and 7th d on hDPCs, cell populations was determined by flow cytometry using an Annexin V detection kit. The data were analyzed statistically using the Kruskal–Wallis test. A p < 0.05 was considered as statistically significant.

Results

All groups showed cell viability similar to that of the control group on 1st, 3rd and 7th d. Although Biodentine exhibited higher cell viability rates than the other material groups, no statistically significant differences were noted between the sampled days (p > 0.05).

Conclusion

All materials extracts are not cytotoxic and do not induce apoptosis in the hDPSCs. These results suggest that all the tested materials can lead to positive outcomes when used as reparative biomaterials.

The Effect of Root End Cavity Preparation Using Er,Cr:YSGG Laser, Ultrasonic Retrotip, and Bur on the Apical Microleakage of Retrograde Cavity Filled with MTA Plus

Aim:

The sealing ability of the retrograde material is greatly affected by the technique used for root end preparation. Advances in retrograde preparation techniques such as lasers has shown to provide an efficient outcome. The study was to evaluate and compare the effect of various techniques of retrograde cavity preparation on apical microleakage.

Materials and Methods:

Forty-five single rooted teeth were decoronated. Biomechanical preparation was carried out up to size F2 ProTaper system and obturated. Glass–ionomer cement was used as an access restorative material. The apical root resection was done at 3 mm from the apex at angulation of 90° to the long axis of the root. The allocation of the samples was done into three groups of 15 each. Group A: Retrograde cavities prepared using conventional round bur; Group B: Retrograde cavities prepared using ultrasonic retro preparation diamond tip; and Group C: Retrograde cavities prepared using “Erbium, chromium: yttrium, scandium, gallium, garnet” (Er,Cr:YSGG). The retrograde cavities hence prepared were filled with MTA Plus. Nail varnish was used to coat the samples except at the apical end. Samples were immersed in methylene blue for 24h. Stereomicroscope was used for examination of the sectioned teeth. The data were analyzed using one-way analysis of variance (ANOVA) and post hoc Tukey test.

Results:

Results showed very highly significant difference between laser and bur (P value = 0.001).

Conclusion:

Retrograde preparation with Er,Cr:YSGG showed significantly less microleakage when compared to the use of ultrasonic retrotip and burs.

Antimicrobial action of NeoMTA Plus on mono- and dual-species biofilms of Enterococcus faecalis and Candida albicans: An in vitro study

OBJECTIVE

To evaluate the antimicrobial action of NeoMTA Plus on mono- and dual-species biofilms of Enterococcus faecalis and Candida albicans.

MATERIAL AND METHODS

A total of 171 sterile dentin blocks, measuring 4 mm × 4 mm × 1 mm, were incubated in media containing E. faecalis (3.1 × 10⁸ cells/mL) and/or C. albicans (1 × 10⁷ cells/mL) for 2 d. These blocks were randomly divided into three groups: the control (no treatment with biomaterials), MTA (treated with an MTA sample with width and thickness same as those of the dentin block after the material was set), and NeoMTA Plus (treated with NeoMTA Plus in a fashion similar to the treatment of the MTA group) groups. The biomaterials remained in contact with the biofilms for 24 h. Quantitative analyses of the number of colony-forming units (CFUs) and metabolic activity (XTT), were performed. Furthermore, qualitative analysis of biofilm structure was performed by scanning electron microscopy. Data were statistically analyzed considering a significance level of 5%.

RESULTS

XTT and the number of CFUs were similar among the groups (p > 0.05). The type of biofilm (mono- or dual-species) or the biomaterial used (MTA or NeoMTA Plus) did not affect the results. Biofilm structure exhibited a robust architecture composed of yeast and bacterial cell multilayers and was homogeneous among the groups.

CONCLUSION

NeoMTA Plus was not effective against mono- and dual-species biofilms of E. faecalis and C. albicans. Further research investigating biofilm removal methods including those involving the use of biomaterials with antiseptics and other supporting therapies is warranted.

Material Pulp Cells and Tissue Interactions

Two increasingly common endodontic procedures, vital pulp therapy (VPT) and regenerative endodontic procedures, rely on dental tissue regeneration/repair mechanisms with the aid of biomaterials. These materials are applied in close contact to the pulpal tissue and are required to be biocompatible, form an antimicrobial seal, not induce staining, and be easy to manipulate. Historically, calcium hydroxide played an important role in VPT. However, over the last 3 decades, significant efforts in research and industry have been made to develop various biomaterials, including hydraulic tricalcium silicate cements. The present review summarized various hydraulic tricalcium silicate cements and their biological properties in clinical procedures, namely VPT and regenerative endodontic procedures.

Radiopacity of endodontic materials using two models for conversion to millimeters of aluminum

The aims of the present study were to compare conventional radiography, radiographs digitized with a scanner or photographic camera, and digital radiography, used to evaluate the radiopacity of endodontic materials, and to compare the accuracy of linear and quadratic models used to convert radiopacity values to equivalent millimeters of aluminum (mm Al). Specimens of AH Plus, Endofill, Biodentine and BioMTA materials (n = 8) were radiographed next to an aluminum step-wedge using radiographic films and digital radiography systems (FONA CMOS sensor, Kodak CMOS sensor and photosensitive phosphor plate-PSP). Conventional radiographs were digitized using a scanner or photographic digital camera. Digital images of all the radiographic systems were evaluated using dedicated software. Optical density units (ODU) of the specimens and the aluminum step-wedge were evaluated by a photo-densitometer (PTDM), used in conventional radiographs. The radiopacity in equivalent mm Al of the materials was determined by linear and quadratic models, and the coefficients of determination (R2) values were calculated for each model. Radiopacity of the materials ranged from -9% to 25% for digital systems and digitized radiographs, compared to the PTDM (p < 0.05). The R2 values of the quadratic model were higher than those of the linear model. In conclusion, the FONA CMOS sensor showed the lowest radiopacity variability of the methodologies used, compared with the PTDM, except for the BioMTA group (higher than PTDM). The quadratic model showed higher R2 values than the linear model, thus indicating better accuracy and possible adoption to evaluate the radiopacity of endodontic materials.

Bio-Inductive Materials in Direct and Indirect Pulp Capping-A Review Article

The article is aimed at analyzing the available research and comparing the properties of bio-inductive materials in direct and indirect pulp capping procedures. The properties and clinical performances of four calcium-silicate cements (ProRoot MTA, MTA Angelus, RetroMTA, Biodentine), a light-cured calcium silicate-based material (TheraCal LC) and an enhanced resin-modified glass-ionomer (ACTIVA BioACTIVE) are widely discussed. A correlation of in vitro and in vivo data revealed that, currently, the most validated material for pulp capping procedures is still MTA. Despite Biodentine’s superiority in relatively easier manipulation, competitive pricing and predictable clinical outcome, more long-term clinical studies on Biodentine as a pulp capping agent are needed. According to available research, there is also insufficient evidence to support the use of TheraCal LC or ACTIVA BioACTIVE BASE/LINER in vital pulp therapy.

Morphological and Spectroscopic Study of an Apatite Layer Induced by Fast-Set Versus Regular-Set EndoSequence Root Repair Materials

This study aimed to evaluate the morphology and chemistry of an apatite layer induced by fast-set versus regular-set EndoSequence root repair materials using spectroscopic analysis. Holes of a 4 mm diameter were created in the root canal dentin, which were filled with the test material. Fetal calf serum was used as the incubation medium, and the samples incubated in deionized water were used as controls. The material-surface and material-dentin interfaces were analyzed after 28 days using Raman and infrared spectroscopy, scanning electron microscopy/energy dispersive X-ray, and X-ray diffraction. After incubation in fetal calf serum, both materials formed a uniform layer of calcium phosphate precipitate on their surfaces, with the dentinal interface. This precipitated layer was a combination of hydroxyapatite and calcite or aragonite, and had a high mineral maturity with the regular-set paste. However, its crystallinity index was high with the fast-set putty. Typically, both consistencies (putty and paste) of root repair material have an apatite formation ability when they are incubated in fetal calf serum. This property could be beneficial in improving their sealing ability for root canal dentin.

Bioactive tri/dicalcium silicate cements for treatment of pulpal and periapical tissues

Over 2500 articles and 200 reviews have been published on the bioactive tri/dicalcium silicate dental materials. The indications have expanded since their introduction in the 1990s from endodontic restorative and pulpal treatments to endodontic sealing and obturation. Bioactive ceramics, based on tri/dicalcium silicate cements, are now an indispensable part of the contemporary dental armamentarium for specialists including endodontists, pediatric dentists, oral surgeons andfor general dentists. This review emphasizes research on how these materials have conformed to international standards for dental materials ranging from biocompatibility (ISO 7405) to conformance as root canal sealers (ISO 6876). Potential future developments of alternative hydraulic materials were included. This review provides accurate materials science information on these important materials. STATEMENT OF SIGNIFICANCE: The broadening indications and the proliferation of tri/dicalcium silicate-based products make this relatively new dental material important for all dentists and biomaterials scientists. Presenting the variations in compositions, properties, indications and clinical performance enable clinicians to choose the material most suitable for their cases. Researchers may expand their bioactive investigations to further validate and improve materials and outcomes.

Bioactive resin-based composite with surface pre-reacted glass-ionomer filler and zwitterionic material to prevent the formation of multi-species biofilm

OBJECTIVE

This study evaluated the synergetic effect between surface pre-reacted glass-ionomer (SPRG) filler and 2-methacryloyloxyethyl phosphorylcholine (MPC), for inhibiting multi-species biofilm formation, while maintaining or even improving the original beneficial features of SPRG-filled resin-based composite (RBC).

METHODS

MPC (1.5-10wt%) was incorporated into commercial SPRG-filled RBC. Then, the inherent properties of RBC, and ion release and acid-neutralising properties associated with SPRG were investigated. Further, protein adsorptions and bacterial adhesion and viability on the SPRG-filled RBC surfaces were studied using four kinds of oral bacteria; Streptococcus mutans, Actinomyces naeslundii, Veillonella parvula, and Porphyromonas gingivalis. Finally, the thickness and biomass of the human saliva-derived biofilm model cultured on test and control samples were analysed.

RESULTS

Addition of MPC content resulted in decreased flexural strength and wettability of SPRG-filled RBC. SPRG-filled RBC released significantly higher amounts of multiple ions as contents of MPC increased. Meanwhile, SPRG-filled RBC with 5-wt% MPC significantly improved acid-neutralising properties than those of other test and control samples (P<0.001). SPRG-filled RBC with 3wt% MPC significantly reduced the amount of adsorbed bovine serum albumin and proteins from the brain heart infusion medium as compared to the control (P<0.01). A similar trend was observed in the attachment of four types of bacteria and multi-species biofilm (P<0.01).

SIGNIFICANCE

Despite limitation in terms of deteriorations of some physical properties, addition of 3% MPC to SPRG-filled RBC leads to inhibition of the attachment of multi-species bacteria on its surface, as well as inhibition of biofilm growth. Moreover, the original important bioactive features of SPRG-filled RBC such as ion release and acid neutralisations are either maintained or improved upon adding MPC.

Pulpal repair after direct pulp capping with new bioceramic materials: A comparative histological study

Aim

To histopathologically evaluate the pulpal healing after direct pulp capping with TotalFill and compared it with Neo MTA Plus in human tooth cultures.

Methods

Forty sound human premolars freshly extracted for orthodontic reasons were randomly assigned to two experimental groups; group I: TotalFill and group II: Neo MTA Plus. Standardized Class V cavities were prepared on the buccal surface of each tooth where the pulp exposure was performed with a dental explorer. The pulp-exposed teeth were immediately capped with one of the tested materials. The prepared cavities were then finally restored with glass-ionomer cement. Teeth were cultured for three weeks and three months. Then, the cultured teeth were demineralized, sectioned and stained for histopathological evaluation. Data collected and statistically analyzed by using Fisher's exact test. The significance level was set at P ≤ 0.05.

Results

Histopathological analysis showed complete dentin bridge formation and an absence of inflammatory pulp response. Statistical analysis showed no significant differences between the TotalFill and Neo MTA Plus groups during the observation periods. However, a significantly higher thickness of the dentin bridge was found in the group of teeth treated with TotalFill at three months.

Conclusions

TotalFill produced similar favorable pulp healing and repair, and were comparable to Neo MTA Plus. Furthermore, TotalFill can form a thicker dentin bridge compared with Neo MTA Plus.

Effect of ultrasonic activation on dentinal tubule penetration of calcium silicate-based cements

This study investigated the dentinal tubule penetration of mineral trioxide aggregate (MTA), NeoMTA Plus and Biodentine placed by either manual condensation or ultrasonic activation in simulated open apex model. Standardized divergent open apex models were created using palatal roots of 60 human maxillary molars and divided into six groups according to the used cements and activation methods (n = 10): MTA-manual condensation, MTA-ultrasonic activation, NeoMTA Plus-manual condensation, NeoMTA Plus-ultrasonic activation, Biodentine-manual condensation, Biodentine-ultrasonic activation. For the measurement of penetration, the cements were mixed with 0.1% Rhodamin B and 6-mm apical portions of each root canal were obturated in an orthograde direction. The roots were embedded into acrylic blocks, and 1-mm-thick sections were obtained at 3 mm from the apex. Specimens were mounted onto glass slides and scanned under a confocal laser scanning microscope (CLSM) and stereomicroscope. Dentinal tubule penetration areas, depth and percentage were measured using LSM and ImageJ software. The data were analyzed using two-way analysis of variance (anova) with Bonferroni correction (α = 0.05). No correlation was found between stereomicroscope and CLSM analyses (p > .05). CLSM analysis showed no significant differences between MTA, NeoMTA Plus, and Biodentine groups when manual condensation was used (p > .05). Ultrasonic activation did not increase the tubular penetration of MTA, NeoMTA Plus or Biodentine as compared to manual condensation of each material (p > .05). MTA, NeoMTA Plus and Biodentine showed similar tubular penetration when manual condensation was used. Ultrasonic activation of these cements had no effect on tubular penetration of each material as compared to the manual condensation counterparts.

Histology of NeoMTA Plus and Quick-Set2 in Contact with Pulp and Periradicular Tissues in a Canine Model

INTRODUCTION

NeoMTA Plus (Avalon Biomed Inc, Bradenton, FL) is a tricalcium silicate material similar to the first mineral trioxide aggregate product, ProRoot MTA (Dentsply Sirona, York, PA), but with improvements such as decreased setting time, increased ion release, increased water sorption, and nonstaining radiopacifiers. Quick-Set2 (Avalon Biomed Inc) is a newly formulated calcium aluminosilicate material that has a faster setting time and increased acid resistance and is nonstaining. The purpose of this study was to compare the healing of pulpal and periapical tissues in dogs after exposure to NeoMTA Plus and Quick-Set2 after pulpotomy and root-end surgery procedures.

METHODS

Seventy-two teeth (36 for each procedure) in 6 beagle dogs received pulpotomy or root-end surgery using either NeoMTA Plus or Quick-Set2. The dogs were sacrificed at 90 days, and the teeth and surrounding tissues were prepared for histologic evaluation. Sixty teeth were evaluated and scored histologically (29 with pulpotomies and 31 with root-end resections). Specimens were scored for inflammation, quality and thickness of dentin bridging, pulp tissue response, cementum and periodontal ligament formation, and apical bone healing.

RESULTS

Both materials displayed favorable healing at 90 days. The only significant difference was the quality of dentin bridge formation in pulpotomies using NeoMTA Plus compared with Quick-Set2.

CONCLUSIONS

Quick-Set2 and NeoMTA Plus had similar effects on inflammation, pulp response, periodontal ligament and cementum formation, and apical tissue healing in dogs. NeoMTA Plus had superior dentin bridge quality compared with Quick-Set2.

Novel anti-biofouling bioactive calcium silicate-based cement containing 2-methacryloyloxyethyl phosphorylcholine

Calcium silicate-based cements (CSCs) are commonly used for endodontic procedures; however, their antibacterial effects are limited. The objective of this study was to develop a 2-methacryloyloxyethyl phosphorylcholine (MPC)-incorporated CSC with improved antibacterial properties, while maintaining the original advantageous features of CSC. MPC was incorporated into a commercial CSC (Endocem MTA) at 0 wt% (control), 1.5%, 3.0 wt%, 5.0 wt%, 7.5 wt%, and 10 wt%. The setting time, compressive strength, water sorption, and glycerol contact angle were measured. Protein absorption was measured and bacterial adhesion on the surface was evaluated using Enterococcus faecalis. The bactericidal effect was examined by the disc diffusion test. Mineralization ability was assessed based on calcium ion deposition, as assessed by alizarin red staining, after immersion into Hank's balanced salt solution for 7 days. High concentrations of MPC in CSC (7.5 wt% and 10 wt%) increased the setting time, reduced compressive strength, and reduced wettability. MPC (3 wt%) had greater protein repellent and anti-biofouling effects than those of control and test materials (P < 0.001). However, no bactericidal effect was observed for any control or test materials. There was greater calcium ion deposition on the surface of MPC-supplemented CSC than on the control (P < 0.001). The addition of 3 wt% MPC polymer to CSC confers protein-repellent properties and reduced bacterial attachment, with the potential for improved mineralization.

Higher hydration performance and bioactive response of the new endodontic bioactive cement MTA HP repair compared with ProRoot MTA white and NeoMTA plus

The aim of this study was to characterize the hydration performance and the bioactive response of the new bioactive endodontic cement MTA HP repair (HP), comparing its physicochemical parameters with those of ProRoot MTA White (Pro) and NeoMTA Plus (Neo). Un-hydrated precursor materials were characterized by X-ray fluorescence, laser diffraction, N₂ physisorption and field emission gun scanning electron microscopy (FEG-SEM). Setting time was assessed according to ASTM specification C 266. Hydrated materials were analyzed by X-ray diffraction, Fourier transform infrared spectroscopy (FT-IR) and (FEG-SEM). Bioactivity evaluation in vitro was carried out, by soaking processed cement disk in simulated body fluid (SBF) during 168 h. The cements surface was studied by FT-IR, FEG-SEM, and energy dispersive X-ray. Release to the SBF media of ionic degradation products was monitored using inductively coupled plasma atomic emission spectroscopy. HP showed shorter initial setting time compared to Pro and Neo and produce a quick and effective bioactive response in vitro in terms of phosphate phase surface coating formation. This higher bioactive response for HP is correlated with increasing calcium aluminate content, increasing surface area of un-hydrated powder precursor and the increasing release capacity of Si ionic products of the final hydrated product. The higher bioactive response of MTA HP repair highlights this material, as very interesting to further investigate its performance to improve the outcome of vital pulp therapy procedures. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2109-2120, 2019.

Effect of titanium tetrafluoride addition on the physicochemical and antibacterial properties of Biodentine as intraorfice barrier

OBJECTIVE

To evaluate the influence of titanium tetrafluoride (TiF₄) incorporation on the physicochemical and antibacterial properties of Biodentine (BD; Septodont, Saint Maur des Faussés, France) as an intraorfice barrier material.

METHODS

Three different proportions of TiF₄ powder were used with BD; 1wt%, 2wt%, and 3wt%; respectively. BD without TiF₄ addition was used as the control group. The setting time (ST) was determined using Gillmore needle apparatus. Diametral tensile strength (DTS) and fracture resistance were measured in a universal testing machine. Solubility was assessed using mass variation after 7days water storage. The hardness test was conducted using Vickers microhardness tester. The antibacterial activity was assessed using direct contact test against Enterococcus faecalis. Radiopacity was assessed and expressed in thickness of aluminum. Surface topography and elemental composition of modified BD were also assessed. The pH of soaking water was measured up to 168h. Data of tested properties were analyzed using one-way analysis of variance, the paired t-test, two-way repeated measures analysis of variance, and Tukey post hoc tests (P<0.05).

RESULTS

BD-incorporating 2wt% TiF₄ revealed the highest surface microhardness, DTS, and fracture resistance compared with the unmodified group (P<0.001). Higher concentrations of TiF₄ (3wt%) compromised the solubility and prolonged the ST of BD (P<0.05). Bacterial growth of BD-incorporating TiF₄ was significantly reduced when compared with the control group (P<0.05). The tested materials induced alkalization of the soaking water that decreased with time.

SIGNIFICANCE

Biodentine-incorporating TiF₄ (1wt% and 2wt%) is a promising intraorfice barrier material with enhanced physicochemical and antibacterial properties.

The effect of bleaching agents on the compressive strength of calcium silicate-based materials

The present study aimed to evaluate the effect of sodium perborate on the compressive strength of calcium silicate-based materials. ProRoot wMTA, MTA Plus, NeoMTA Plus and Biodentine discs with 5 mm thickness and 4 mm diameter were prepared. Thirty discs from each material were used for compressive strength testing and divided into two groups: control and bleaching (n = 15). The sodium perborate was mixed with 30% hydrogen peroxide in a creamy consistency and placed on the surface of the specimens. Specimens were tested in an Instron machine, and compressive strength values were recorded and compared. The data were analysed using one-way anova and post hoc Tukey tests. Compressive strength of all tested materials significantly decreased after bleaching (P < 0.05). SEM examination revealed deterioration on materials' surfaces after bleaching. Application of sodium perborate and hydrogen peroxide reduced the compressive strength of ProRoot wMTA, MTA Plus, NeoMTA Plus and Biodentine.