Biodentine: from biochemical and bioactive properties to clinical applications

Biodentine™ as a temporary filling in deep carious lesions in permanent teeth: a prospective observational 33-month follow-up study

PURPOSE

The study aimed to evaluate temporary fillings using Biodentine™ in asymptomatic deep carious lesions after 12, 24, and 36 months in school children from the remote village of Kerung, Nepal.

METHODS

From November 2018 to November 2019, 91 temporary fillings were placed using Biodentine™ (a hydraulic calcium silicate cement) in permanent molars with deep carious lesions of schoolchildren in the remote district of Kerung, Nepal. These restorations were performed after selective caries removal in a non-dental setting with hand instruments and cotton roll isolation, as electric motors and saliva ejection systems were unavailable. In total, 78 single-surface and 13 multi-surface fillings were placed. Clinical and radiographic follow-up periods encompassed 12, 21, and 33 months, respectively.

RESULTS

After 12 months, all single-surface fillings (100%) survived, whilst all multi-surface fillings were partially or entirely lost. The survival rate of single-surface restorations after 21 and 33 months was 67.6% and 50%, respectively. Radiographically, no pathology was observed.

CONCLUSION

This study showed that Biodentine could be used in deep carious lesions as a temporary filling in single-surface lesions for at least up to 1 year and in a substantial number of cases for up to 21 and 33 months.

Dentine Remineralisation Induced by "Bioactive" Materials through Mineral Deposition: An In Vitro Study

This study aimed to assess the ability of modern resin-based "bioactive" materials (RBMs) to induce dentine remineralisation via mineral deposition and compare the results to those obtained with calcium silicate cements (CSMs). The following materials were employed for restoration of dentine cavities: CSMs: ProRoot MTA (Dentsply Sirona), MTA Angelus (Angelus), Biodentine (Septodont), and TheraCal LC (Bisco); RBMs: ACTIVA BioACTIVE Base/Liner (Pulpdent), ACTIVA Presto (Pulpdent), and Predicta Bioactive Bulk (Parkell). The evaluation of the mineral deposition was performed through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) on the material and dentine surfaces, as well as at the dentine-material interface after immersion in simulated body fluid. Additionally, the Ca/P ratios were also calculated in all the tested groups. The specimens were analysed after setting (baseline) and at 24 h, 7, 14, and 28 days. ProRoot MTA, MTA Angelus, Biodentine, and TheraCal LC showed significant surface precipitation, which filled the gap between the material and the dentine. Conversely, the three RBMs showed only a slight ability to induce mineral precipitation, although none of them was able to remineralise the dentine-material interface. In conclusion, in terms of mineral precipitation, modern "bioactive" RBMs are not as effective as CSMs in inducing dentine remineralisation; these latter represent the only option to induce a possible reparative process at the dentin-material interface.

Comparative biological properties of resin-free and resin-based calcium silicate-based endodontic repair materials on human periodontal ligament stem cells

OBJECTIVES

To investigate the effect of three different calcium silicate-based materials (CSBM) on the biological behavior of human periodontal ligament stem cells (hPDLSCs).

METHODS

Eluates of Biodentine, NeoPutty and TheraCal PT prepared at 1:1, 1:2, and 1:4 ratios were extracted under sterile conditions. The cytotoxicity of the extracts to the hPDLSCs was assessed using the MTT assay. Scratch wound healing assay was utilized for assessing cell migration. Scanning electron microscopy was used to detect cell attachment and morphology. Calcium ion release was measured using inductively coupled plasma-optical emission spectrometry; the pH-value was evaluated with a pH-meter. ANOVA with post hoc Tukey test was used for statistical analysis.

RESULTS

Cell viability was significantly higher for Biodentine and NeoPutty at day 1 with all dilutions (p < 0.05), while at day 3 and day 7 with dilutions 1:2 and 1:4; all materials showed similar behavior (p > 0.05). Biodentine had the highest percentage of cell migration into the scratched area at day 1 for all dilutions (p < 0.05). Stem cells were attached favorably on Biodentine and NeoPutty with evident spreading, and intercellular communications; however, this was not shown for TheraCal PT. Biodentine showed the highest pH values and calcium ion release (p < 0.05).

CONCLUSIONS

The resin-free CSBM showed better performance and favorable biological effects on hPDLSCs and were therefore considered promising for usage as endodontic repair materials.

CLINICAL SIGNIFICANCE

Proper selection of materials with favorable impact on the host stem cells is crucial to ensure outcome in different clinical scenarios.

Effect of different irrigants on the push-out bond strength of biodentine and TheraCal LC when used for perforation repair in simulated condition

Background

Perforation repair materials should have excellent sealing ability and dislodgement resistance. While several materials have been employed for perforation repair, newer calcium-silicate materials, such as Biodentine and TheraCal LC, have shown promising outcomes.

Aims

This study aimed to evaluate the effect of different irrigants on the dislodgement resistance of Biodentine and TheraCal LC when used for perforation repair in simulated conditions.

Methods and Material

3% sodium hypochlorite, 2% chlorhexidine gluconate, and 17% EDTA were evaluated for their effect on the dislodgement resistance of Biodentine and TheraCal LC. 48 permanent mandibular molars were selected for the study. The samples were divided into two groups: Group I - Biodentine and Group II - TheraCal LC, with 24 samples each.

Statistical Analysis

The mean dislodgement resistance and standard deviation of Group I (Biodentine) and Group II (TheraCal LC) were compared and Failure pattern analysis was done.

Results

Biodentine showed a significant decrease in push-out bond strength after contact with 3% NaOCl, 2% CHX, and 17% EDTA whereas, TheraCal LC showed no significant decrease in push-out bond strength after exposure to 3% NaOCl, 2% CHX, and 17% EDTA.

Conclusions

Overall, TheraCal LC can be considered good perforation repair material with excellent physical and biological properties.

Effects of Apical Barriers and Root Filling Materials on Stress Distribution in Immature Teeth: Finite Element Analysis Study

PURPOSE

A finite element analysis (FEA) study was performed to determine whether the material of apical barrier used for root apexification and/or the use of canal reinforcement affect the stress distribution in an endodontically treated immature permanent tooth in order to infer in which clinical scenarios a fracture is more likely to occur based on the ultimate tensile strength threshold of dentin.

METHODS AND MATERIALS

An extracted human immature mandibular premolar was selected as the reference model and scanned by micro-computed tomography (micro-CT). The digital model was segmented and converted to STL (Standard Tessellation Language) using Simpleware Scan-IP and exported in IGES (Initial Graphics Exchange Specification) to Ansys 19. Six experimental models were designed with different combinations of composite, mineral trioxide aggregate (MTA), and Biodentine (BIO). Using FEA, a static 300N load at a 135 angle with respect to the axis of the tooth was applied to each model and Von-Mises stress values (MPa) were measured at the sagittal, apical 8mm, 5mm, 2mm, and 1mm levels.

RESULTS

In all regions examined, the control (NT model) had lower stress in the root compared to experimental models. At the mid-root level, models with composite, MTA, and BIO reinforcement exhibited lower stresses in the root dentin than those with pulp or gutta-percha. BIO models had equal or greater average Von-Mises stress values than those of MTA models in all regions. Both, MTA and BIO, caused increases in stress of surrounding root dentin, with BIO causing a greater increase than MTA.

CONCLUSIONS

Stress distribution in immature permanent teeth treated by apexification is affected by the types of materials used. Root dentin's stress was lower when the mid-root canal was reinforced by composite, MTA, or BIO, which provided similar stress reduction to the root dentin. MTA is a more favorable apical barrier material from a mechanical standpoint because it induces less stress on apical root dentin than BIO.

Biomimetic Approaches in Clinical Endodontics

In the last few decades, biomimetic concepts have been widely adopted in various biomedical fields, including clinical dentistry. Endodontics is an important sub-branch of dentistry which deals with the different conditions of pulp to prevent tooth loss. Traditionally, common procedures, namely pulp capping, root canal treatment, apexification, and apexigonesis, have been considered for the treatment of different pulp conditions using selected materials. However, clinically to regenerate dental pulp, tissue engineering has been advocated as a feasible approach. Currently, new trends are emerging in terms of regenerative endodontics which have led to the replacement of diseased and non-vital teeth into the functional and healthy dentine-pulp complex. Root- canal therapy is the standard management option when dental pulp is damaged irreversibly. This treatment modality involves soft-tissue removal and then filling that gap through the obturation technique with a synthetic material. The formation of tubular dentine and pulp-like tissue formation occurs when stem cells are transplanted into the root canal with an appropriate scaffold material. To sum up tissue engineering approach includes three components: (1) scaffold, (2) differentiation, growth, and factors, and (3) the recruitment of stem cells within the pulp or from the periapical region. The aim of this paper is to thoroughly review and discuss various pulp-regenerative approaches and materials used in regenerative endodontics which may highlight the current trends and future research prospects in this particular area.

The Effect of Irrigation with Citric Acid on Biodentine Tricalcium Silicate-Based Cement: SEM-EDS In Vitro Study

There are various factors that may interfere with the activity of biomaterials during endodontic therapy. One of them is the canal system irrigation procedure with different rinsing solutions performed after the placement of bioactive cements. The authors investigate the influence of citric acid, a chelating agent, on the surface and the chemical composition of Biodentine tricalcium silicate-based cement using a multimethod approach. Twenty samples were divided into two groups based on the material setting time. They were subjected to citric acid irrigation with or without ultrasonic activation for 5 and 20 min. The chemical analysis was made with energy dispersive spectroscopy (EDS). The visual assessment of Biodentine surface was carried out in scanning electron microscope (SEM). The volume of material loss during the procedure was measured with Keyence optic microscope and dedicated digital software. Statistical analysis was performed. The results of the study show that the irrigation with citric acid influenced the surface appearance of the material and changed its chemical composition in both investigated groups. The ultrasonic activation (US) of the liquid has also aggravated its impact. Further research is needed to assess if that fact may change the sealing properties of the material influencing the long-term clinical outcome.

Subcutaneous tissue reaction and gene expression of inflammatory markers after Biodentine and MTA implantation

The aim of this study was to evaluate the subcutaneous connective tissue response of isogenic mice exposed to tricalcium silicate (Biodentine) and aggregated mineral trioxide (ProRoot MTA). A total of 120 mice were divided into 4 groups in 3 different experimental periods (7, 21 and 63 days): Biodentine; Pro-Root MTA; zinc oxide-eugenol and; Negative control - Sham. After the experimental periods microscopic descriptive, semi-quantitative and quantitative analysis of the inflammatory process were analyzed on H&E sections and evaluation of the gene expression of Il10, Infg, Il6, Il1r1 and Tnf (qRT-PCR) were performed. The data obtained were analyzed using the chi-square test and two-way analysis of variance (ANOVA) followed by the Bonferroni post-test (5% significance level). Results: In the microscopic analysis, a slight inflammatory infiltrate was observed, with a predominance of sparse macrophages and polymorphonuclear cells, slight tissue fibrosis, regular fibrous capsule and with dystrophic calcifications, in all groups that received the materials (Biodentine and Pro-Root MTA). In parallel, all materials modulated the gene expression of the different cytokines and receptors evaluated. Conclusion: Pro-Root MTA and Biodentine showed a tissue compatibility, mediated inflammation, with increased fibrous tissue and production of pro- and anti-inflammatory cytokines.

Application of Selected Biomaterials and Stem Cells in the Regeneration of Hard Dental Tissue in Paediatric Dentistry-Based on the Current Literature

Currently, the development of the use of biomaterials and their application in medicine is causing rapid changes in the fields of regenerative dentistry. Each year, new research studies allow for the discovery of additional possibilities of dental tissue restoration. The structure and functions of teeth are complex. They consist of several diverse tissues that need to act together to ensure the tooth’s function and durability. The integrity of a tooth’s enamel, dentin, cementum, and pulp tissue allows for successful mastication. Biomaterials that are needed in dentistry must withstand excessive loading forces, be biocompatible with the hosts’ tissues, and stable in the oral cavity environment. Moreover, each tooth’s tissue, as well as aesthetic qualities in most cases, should closely resemble the natural dental tissues. This is why tissue regeneration in dentistry is such a challenge. This scientific research focuses on paediatric dentistry, its classification of caries, and the use of biomaterials in rebuilding hard dental tissues. There are several methods described in the study, including classical conservative methods such as caries infiltration or stainless-steel crowns. Several clinical cases are present, allowing a reader to better understand the described methods. Although the biomaterials mentioned in this work are artificial, there is currently ongoing research regarding clinical stem cell applications, which have a high potential for becoming one of the most common techniques of lost dental-tissue regeneration in the near future. The current state of stem cell development is mentioned, as well as the various methods of its possible application in dentistry.

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

Vital pulp therapy (VPT) is deliberated as an ultraconservative/minimally invasive approach for the conservation of vital pulpal tissues, preservation of dental structure, and maintenance of tooth function in the oral cavity. In VPT, following the exposure of the dental pulp, the environment is prepared for the possible healing and probable refunctionalisation of pulpal connective tissue. However, to succeed in VPT, specific biomaterials are used to cover and/or dress the exposed pulp, lower the inflammation, heal the dental pulp, provoke the remaining odontoblastic cells, and induce the formation of a hard tissue, i.e., the dentinal bridge. It can be assumed that if the employed biomaterial is transferred to the target site using a specially designed micro-/nanosized local drug delivery system (LDDS), the biomaterial would be placed in closer proximity to the connective tissue, may be released in a controlled and sustained pattern, could properly conserve the remaining dental pulp and might appropriately enhance hard-tissue formation. Furthermore, the loaded LDDS could help VPT modalities to be more ultraconservative and may minimise the manipulation of the tooth structure as well as pulpal tissue, which could, in turn, result in better VPT outcomes.

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.

The Effect of Calcium-Silicate Cements on Reparative Dentinogenesis Following Direct Pulp Capping on Animal Models

Dental pulp vitality is a desideratum for preserving the health and functionality of the tooth. In certain clinical situations that lead to pulp exposure, bioactive agents are used in direct pulp-capping procedures to stimulate the dentin-pulp complex and activate reparative dentinogenesis. Hydraulic calcium-silicate cements, derived from Portland cement, can induce the formation of a new dentin bridge at the interface between the biomaterial and the dental pulp. Odontoblasts are molecularly activated, and, if necessary, undifferentiated stem cells in the dental pulp can differentiate into odontoblasts. An extensive review of literature was conducted on MedLine/PubMed database to evaluate the histological outcomes of direct pulp capping with hydraulic calcium-silicate cements performed on animal models. Overall, irrespective of their physico-chemical properties and the molecular mechanisms involved in pulp healing, the effects of cements on tertiary dentin formation and pulp vitality preservation were positive. Histological examinations showed different degrees of dental pulp inflammatory response and complete/incomplete dentin bridge formation during the pulp healing process at different follow-up periods. Calcium silicate materials have the ability to induce reparative dentinogenesis when applied over exposed pulps, with different behaviors, as related to the animal model used, pulpal inflammatory responses, and quality of dentin bridges.

Effect of different manipulations on the physical, chemical and microstructural characteristics of Biodentine

OBJECTIVE

The water to powder ratio and method of mixing is important for the properties of hydraulic cements. For this purpose a number of clinicians prefer premixed materials. Dental manufacturing companies provide predosed materials, however the manufacturer instructions are not always adhered to. The aim of this research is to investigate physical and chemical alterations of the tricalcium silicate-based cement Biodentine when manipulated according to the manufacturer's instructions (control) or changing the doses and mixing of the material components.

METHODS

6 groups were constituted according to different mixing and dosing of powder and liquid. The hydrated cements were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). Calcium ion concentration of the leachate was also investigated. Assessment of the physical characteristics included setting time and microhardness.

RESULTS

Microstructural differences were visible only in the Biodentine mixed manually with water, in which early hydration rate was also affected, with lower calcium ion release. Increase of Biodentine liquid increased the calcium ion release, but also increased the setting time. Manual manipulation required more liquid (both water and Biodentine liquid) added to the mixture to guarantee a similar consistency to the control. A decrease in setting time was also noted. All groups showed higher values of microhardness at 24 h compared to the freshly set materials. In the freshly set materials, there was an overall decrease in microhardness in all groups when compared to group control, particularly significant when increasing the dosage of Biodentine liquid.

SIGNIFICANCE

When mixing Biodentine, altering the mixing procedure in terms of type and amount of liquid added to the powder and mixing device chosen has an effect on the physical, chemical and mechanical characteristics and surface topography of the material, when compared to Biodentine mixed according to the manufacturer's recommendations. Hence, the manufacturer's instructions should be strictly followed.

Evaluation of the Bond Strength of Different Pulp Capping Materials to Dental Adhesive Systems: An In Vitro Study

Aim:

To evaluate the bond strengths of pulp capping materials (Dycal, ProRoot MTA, Biodentine, TheraCal LC, Calcimol LC, and ApaCal ART) and different adhesive systems (Gluma 2 Bond, Clearfil SE Protect, Gluma Self Etch, Clearfil S 3 Bond Plus, Gluma Bond Universal, Clearfil S 3 Bond Universal).

Materials and Methods:

Two hundred fifty-two acrylic blocks were prepared in which cylindrical cavities of 4 × 2 mm 3 were formed. Pulp capping materials were placed in the cavities. Different adhesive systems were applied to each pulp capping material group. After applying the composite resin, the shear bond strength (SBS) values of the specimens were determined in the Instron test device. Fracture types were evaluated using a stereomicroscope and a scanning electron microscope. Data were analyzed by Shapiro–Wilk’s and Kruskal–Wallis H test.

Results:

There is a statistically significant difference between pulp capping materials in terms of SBS values ( P < .05). Dycal’s SBS was found significantly lower than other materials, and the highest bond strength was observed in Calcimol LC material. Although there is no statistically significant difference ( P > .05) between the adhesive agent groups in terms of SBS, Gluma 2 Bond showed the highest bond strength value.

Conclusion:

In traditional pulp capping materials such as Dycal, MTA, and Biodentine, using a two-step self-etch adhesive system can result in higher bond strength values. In resin-based TheraCal LC,, ApaCal ART, and Calcimol LC materials, it may be recommended to use a two-step etch and rinse adhesive system.

Intentional replantation and Biodentine root reconstruction. A case report with 10-year follow-up

AIM

To describe the innovative use of intentional replantation for Biodentine root reconstruction of a previously treated immature maxillary central incisor with vertically extended crown root fracture and root detachment.

SUMMARY

In the present case, the intentional replantation of a failing, previously treated maxillary central incisor with a vertical crown/root fracture in a 12-year-old male patient is reported. The gross extrusion of gutta-percha points beyond the apex and the pre-existing extensive, trauma related, distal cervical dentinal detachment justified the intentional replantation treatment plan as an option for tooth retention. After controlling the infection by oral administration of antibiotics, the immature tooth was extracted atraumatically and kept in gauze embedded with tooth replantation medium. The apical third of the immature fractured tooth was treated with ultrasonics and an MTA plug (MTA Angelus White, Londrina, Brazil). The distal cervical dentinal root defect was reconstructed with Biodentine (Septodont, St. Maur-des-Fosses, France). The tooth was reinserted and stabilized to the adjacent teeth for 2 weeks. The total extraoral time before replantation was 25 min. In the 10 years since the initial trauma (9 years after the intervention) radiographic and clinical evaluation revealed uneventful healing of the periapical lesion, normal mobility and no detectable signs of external replacement resorption.

KEY LEARNING POINTS

Intentional replantation may provide a viable treatment alternative in cases of severe complicated crown/ root fractures Biodentine may be useful in the reconstruction of external root defects in crown root fractured traumatic dental injuries.

Influence of sodium hypochlorite and ultrasounds on surface features and chemical composition of Biodentine tricalcium silicate-based material

Biomaterials are subjected to various factors during endodontic workflow. The aim was to evaluate the influence of different concentrations of sodium hypochlorite and ultrasound activation on the features and chemical composition of Biodentine. Fifty-four Biodentine samples were divided into 3 groups based on the material setting time. They were subjected to different modes and times of 2% and 5.25% NaOCl irrigation with or without ultrasounds, 12 min (group I), 45 min (group II) and 24 h (group III) after the material mixing. Visual assessment of the sample's surface was performed using the scanning electron microscope and chemical analysis was made with energy dispersive spectroscopy. Both NaOCl irrigation and ultrasounds affected the surface of the material; however, they did not change its chemical composition. The irrigation enhanced by ultrasounds following the placement of Biodentine should be performed after a longer material setting time. The immediate use of ultrasounds is not recommended.

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.

Clinical and radiographic evaluation of Biodentine and Mineral Trioxide Aggregate in revascularization of non-vital immature permanent anterior teeth (randomized clinical study)

OBJECTIVE

To asses clinically and radiographically the effect of using two types of coronal plug materials in revascularization of non-vital immature teeth.

METHODS

A total of 26 necrotic immature permanent anterior teeth were enrolled for pulp revascularization using a double antibiotic mix for root canal disinfection. They were randomly divided into the following based on coronal plug materials used: Biodentine (Group I) and white Mineral Trioxide Aggregate (Group II; n = 13). Clinical and radiographic assessments were performed after 3, 6, 9, and 12 months.

RESULTS

When comparing the overall clinical successes and percentage of increase in root length between the two groups, there was no statistically significant difference (P > 0.05). There was a significant difference in the distribution of discoloration between the two groups. One case was reported in Group I, and seven cases were reported in Group II (P = 0.01).

CONCLUSIONS

Both Biodentine and Mineral Trioxide Aggregate were successful clinically regarding the resolution of signs and symptoms associated with the necrotic teeth.

The Application of 29Si NMR Spectroscopy to the Analysis of Calcium Silicate-Based Cement using Biodentine™ as an Example

Biodentine is one of the most successful and widely studied among the second generation of calcium silicate-based endodontic cements. Despite its popularity, the setting reactions of this cement system are not currently well understood. In particular, very little is known about the formation and structure of the major calcium silicate hydrate (C-S-H) gel phase, as it is difficult to obtain information on this poorly crystalline material by the traditional techniques of powder X-ray diffraction analysis (XRD) and Fourier transform infrared spectroscopy (FTIR). In this study, the hydration reactions of Biodentine are monitored by XRD, FTIR, isothermal conduction calorimetry and, for the first time, 29Si magic angle spinning nuclear magnetic resonance spectroscopy (29Si MAS NMR) is used to investigate the structures of the anhydrous calcium silicate phases and the early C-S-H gel product. XRD analysis indicated that the anhydrous powder comprises 73.8 wt% triclinic tricalcium silicate, 4.45 wt% monoclinic β-dicalcium silicate, 16.6 wt% calcite and 5.15 wt% zirconium oxide. Calorimetry confirmed that the induction period for hydration is short, and that the setting reactions are rapid with a maximum heat evolution of 28.4 mW g-1 at 42 min. A progressive shift in the FTIR peak maximum from 905 to 995 cm-1 for the O-Si-O stretching vibrations accompanies the formation of the C-S-H gel during 1 week. The extent of hydration was determined by 29Si MAS NMR to be 87.0%, 88.8% and 93.7% at 6 h, 1 day and 1 week, respectively, which is significantly higher than that of MTA. The mean silicate chain length (MCL) of the C-S-H gel was also estimated by this technique to be 3.7 at 6 h and 1 day, and to have increased to 4.1 after 1 week. The rapid hydration kinetics of Biodentine, arising from the predominance of the tricalcium silicate phase, small particle size, and 'filler effect' of calcite and zirconium oxide, is a favorable characteristic of an endodontic cement, and the high values of MCL are thought to promote the durability of the cement matrix.

TheraCal LC: From Biochemical and Bioactive Properties to Clinical Applications

Background

Direct pulp capping is a popular treatment modality among dentists. TheraCal LC is a calcium silicate-based material that is designed as a direct/indirect pulp capping material. The material might be very attractive for clinicians because of its ease of handling. Unlike other calcium silicate-based materials, TheraCal LC is resin-based and does not require any conditioning of the dentine surface. The material can be bonded with different types of adhesives directly after application. There has been considerable research performed on this material since its launching; however, there are no review articles that collates information and data obtained from these studies. This review discusses the various characteristics of the material with the aim of establishing a better understanding for its clinical use.

Methods

A search was conducted using search engines (PubMed and Cochrane databases) in addition to reference mining of the articles that was used to locate other papers. The process of searching for the relevant studies was performed using the keywords pulp protection, pulp capping, TheraCal, and calcium silicates. Only articles in English published in peer-reviewed journals were included in the review.

Conclusion

This review underlines the fact that further in vitro and in vivo studies are required before TheraCal LC can be used as a direct pulp capping material.

Chemical Composition and Porosity Characteristics of Various Calcium Silicate-Based Endodontic Cements

Chemical composition and porosity characteristics of calcium silicate-based endodontic cements are important determinants of their clinical performance. Therefore, the aim of this study was to investigate the chemical composition and porosity characteristics of various calcium silicate-based endodontic cements: MTA-angelus, Bioaggregate, Biodentine, Micromega MTA, Ortho MTA, and ProRoot MTA. The specific surface area, pore volume, and pore diameter were measured by the porosimetry analysis of N2 adsorption/desorption isotherms. Chemical composition and powder analysis by scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were also carried out on these endodontic cements. Biodentine and MTA-angelus showed the smallest pore volume and pore diameter, respectively. Specific surface area was the largest in MTA-angelus. SEM and EDS analysis showed that Bioaggregate and Biodentine contained homogenous, round and small particles, which did not contain bismuth oxide.