3.2.1.1 ProRoot MTA

ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK, USA) (Figure 3.1) is the first primitive form of bioceramics and was produced in 1993. Then, the white and tooth‐colored forms were manufactured in 2002. Principal components of the material are tricalcium silicate, dicalcium silicate, bismuth oxide, and calcium sulfate. Bismuth oxide is the radiopacifier inside the material and the possible responsible ingredient for the discoloration [8]. Its liquid is 100% distilled water. It has high radiopacity (6.47 mm aluminum [Al]) [4].

It has been used in endodontics for its low cytotoxicity, biocompatibility, and osteogenetic and cementogenetic features [9, 10]. It complies with ISO standards (ISO 9917) [9]. Setting time is three to four hours [8]. It has a better adaptation to dentine when compared to formerly used materials like amalgam [11]. On the other hand, it should be applied at least 3 mm to increase the sealing and adherence ability during apical surgery applications or root repair. The origin of the adaptation comes from the hydroxyapatite crystals that appear in the product’s consequent series of reactions [11]. It can be used for pulp capping, apexification, root‐end filling, perforation and resorption repair [4]. Kim et al. [12] observed that the use of MTA in pulp capping created in an inflammatory environment reduced the inflammation. Although it has excellent features, the tough handling and long setting time still constitute some problems in clinical applications [13].

3.2.2.1 MTA Angelus

MTA Angelus (Angelus, Londrina, Brazil) is bioceramic regenerative cement containing MTA. It was launched in 2001 in two forms, gray and white [14]. It is boxed as powder and liquid in a bottle which is easier than ProRoot MTA to store for reuse. The powder contains 80% Portland cement and 20% bismuth oxide [15]. Its liquid is distilled water. Each box contains five 1 g bottles and a 3 ml liquid bottle.

MTA Angelus has an initial curing time of 10 minutes and a final setting time of 15 minutes. It was reported that it can be a good option in clinical use because of its short setting time [16]. Owing to its lower bismuth oxide content, it shows less radiopacity than ProRoot MTA [17]. Its marginal adaptation was found to be lower than MTA [18].

Some additives such as calcium oxide in its contents are aimed at enhancing the early release of calcium hydroxide [19]. The early release of these calcium ions accelerates dentine bridge formation and biological healing after pulp capping. It also provides biological repair of perforations and injured periradicular tissues. Calcium sulfate in its content has been removed to reduce the setting time [20]. It is biologically compatible and does not show cytotoxic and mutagenic properties [21–23]. In addition, according to the results of some studies, MTA Angelus has antimicrobial properties [15, 16, 20].

Its content allows it to be used under moist conditions. Therefore, it is easy to use and has wide indications in endodontic practice such as perforations, apexification, internal resorption, pulpotomy, pulp exposure, root‐end fillings, apexification, and apexogenesis [19].

3.2.2.2 MTA Bio

MTA Bio (Angelus Ind. Prod., Londrina, Brazil) is a water‐based Portland cement synthesized under highly controlled laboratory conditions and developed to prevent the presence of arsenic and lead in cement dust [24]. It is known that its content consists of 80% Portland cement and 20% bismuth oxide [25]. The manufacturer reports that the final cement is free of unwanted contaminants, especially arsenic [26].

It sets completely in two hours [27]. The radiopacity of MTA Bio was found to comply with the 3 mm Al radiopacity [27]. Owing to its low solubility and high purity, it shows low cytotoxicity on odontoblast‐like cells [28]. It has been reported that it is more effective in wound healing and accelerates healing after pulp capping or pulpotomy [28].

3.2.2.3 MM‐MTA™

MM‐MTA™ (Micro‐Mega Besancon, France) (Figure 3.2) is water‐insoluble endodontic repair cement. It was developed in 2011 [29]. The content is as follows: tricalcium silicate, bismuth oxide, tricalcium aluminate, magnesium oxide, calcium sulfate dihydrate, calcium carbonate (CaCO₃), and chloride accelerator [30]. MM‐MTA™ consists of powder and liquid capsules. Its powder consists of very fine hydraulic particles of several mineral oxides. It is mixed automatically with a vibrating mixer. Thus, powder and liquid are always mixed in the right proportion, and homogeneity of the material can be achieved [31].

It has been reported that the working time of MM‐MTA™ is approximately 2 minutes (at 23 °C) and the setting time is 20 minutes [32]. The short setting time is related to the calcium carbonate and chloride accelerator content [33]. Also, calcium carbonate makes the manipulation of MM‐MTA™ easier [30]. Its radiopacity is similar to that of MTA.

It has been shown that MM‐MTA™ is safe to use because it contains acceptable levels of arsenic, lead, and metal oxides [34]. It is biocompatible and has excellent adhesion to dentine [30]. MM‐MTA™ was shown to support odontologic [35] and osteogenic differentiation stem cells [36].

3.2.3.1 EndoSeal MTA

EndoSeal MTA (Maruchi, Wonju, Korea) (Figure 3.3a) is a ready‐to‐use, injectable, pozzolan‐based root canal sealer. Thanks to its high fluidity, it could be used with the single‐cone technique [37, 38]. It has ingredients similar to the MTA, such as calcium silicates, calcium aluminates, calcium aluminoferrite, calcium sulfates, radiopacifier, and a thickening agent [39].

EndoSeal MTA absorbs the ambient moisture in the root canal throughout the setting reaction [40]. It completes its self‐curing and no mixing is required [41]. Therefore, it is less technique sensitive. Its setting time has been reported as 12.31 minutes [39]. In a review of calcium silicate‐based‐sealers, it was reported that EndoSeal MTA has similar solubility, lower radiopacity, and higher alkalinity and fluidity compared to AH Plus sealer [42].

It has been indicated that EndoSeal MTA has the good sealing ability, dimensional stability, insolubility, and optimal biocompatibility [41, 43]. It also provides satisfactory and favorable biological and physicochemical properties [44] It has good bond strength to dentine, high fracture resistance [45], low discoloration [39, 46], and superior sealer distribution [47]. Also, its alkalinity level is similar to MTA [41]. Recent studies reported that the antibacterial activity of EndoSeal MTA is highly effective [48], and comparable to that of ProRoot MTA [49].

3.2.3.2 MTA Fillapex

MTA Fillapex (Angelus, Londrina, PR, Brazil) (Figure 3.3d) is a disalicylate resin‐based endodontic sealer that contains 40% MTA particles [50]. It was introduced commercially in 2010 with a high sealing capacity and ability to promote cementum regeneration [51]. According to the manufacturer, its ingredients are as follows (Paste A and Paste B, respectively): salicylate resin for ionic polymer formation, bismuth trioxide for radiopacity, fumed silica as filler, 40% MTA as active ingredient and responsible for ionic polymer formation, base resin for plasticity, fumed silica as filler and titanium dioxide as pigment. It is ready to use [52]. The material has excellent calcium ion release, biocompatibility, excellent flow, and easy removal. Despite that, it has also been reported that it releases less calcium ions than MTA and that no calcium hydroxide is detected during its hydration [53].

It was stated that the setting time of the material was 19.3 minutes and the failure of the material setting procedure was observed in dry conditions [39].

Contrary to the manufacturer’s instructions [52] and some studies, there are also studies stating that MTA Fillapex is highly cytotoxic [54] and induces a long‐term inflammatory reaction [55]. It has been demonstrated that the cytotoxicity of MTA Fillapex may be due to its alkaline pH [56], high dissolution rate [57] or incapability in releasing ions required for apatite formation [58], and entity of resin in the MTA‐Fillapex’s structure [59].

3.2.3.3 TheraCal LC

TheraCal LC (Bisco Inc, Schaumburg, IL, USA) (Figure 3.3c) which is a light‐curing, resin‐modified, Portland cement‐based filled liner developed in 2011. It is aimed to be used as a protective base under restorative materials in direct and indirect pulp capping therapies. It is used for the protection and isolation of the dental pulpal complex. It is composed of 45% type III Portland cement, 40% resin, 10% barium sulfate for radiopacity, and 5% fumed silica [60].

The product does not need mixing. It is packaged and ready to use in a syringe.

According to the manufacturer, the tricalcium silicate particles in the hydrophilic resin matrix of the TheraCal LC provide a significant calcium ion release (213 (μg/cm²)/24 h). The ion release stimulates hydroxyapatite and the dentine bridge formation provides a tight seal and makes the material uniquely stable. It is stated by the manufacturer that its alkaline pH (10–11 in three hours) can promote healing, pulpal vitality, and apatite formation. In addition, due to the light‐curing structure of the material, it allows the restorative material to be placed immediately, providing easy handling usage for the clinician. It has 2.6 mm Al radiopacity. TheraCal LC can be used with all etch techniques (self‐selective and total‐etch) for optimal bonding of the restoration. It is moisture tolerant and will not wash out or dissolve over time. In a recently published meta‐analysis, it was stated that the bond strength of TheraCal LC to resin composite materials is better when using a total‐etch adhesive system [61]. The manufacturer recommends light‐curing each 1 mm cement for 20 seconds [62].

3.2.3.4 TheraCal PT

TheraCal PT (Bisco, Inc., Schaumburg, IL, USA) (Figure 3.3b) is a new, resin‐modified Portland‐based material. It is dual‐cured. It has been marketed in a syringe and is ready to use. According to the manufacturer, it is primarily indicated for pulpotomy, and it may also be used for direct (pulp exposures) and indirect (protective liner) vital pulp therapies. The chemical formulation of TheraCal PT is similar to TheraCal LC and contains synthetic Portland cement and calcium silicate particles in a hydrophilic matrix. It has been stated that this structure facilitates calcium release [63].

The manufacturer of the product claimed that its pH is 11.5 at seven days; it presents low water solubility and has 2.45 mm Al radiopacity. It is reported by the manufacturer that TheraCal PT has minimum 45 seconds of working time at 35 °C and maximum of 5 minutes of setting time at 35 °C. This allows the treatment to be completed in a single session [63].

In recent studies carried out to test the bioactive properties of the material, TheraCal PT was found to be less cytotoxic than TheraCal LC [64], and TheraCal PT exhibited similar biological results as MTA Angelus [64], and Biodentine [65]. Another recently published study noted that TheraCal PT exhibited limited bioactivity [66]. However, more in vitro, in vivo, and clinical studies are needed for TheraCal PT.

3.2.4.1 BioAggregate

BioAggregate (Innovative Bioceramix, Vancouver, BC, Canada) is a novel laboratory‐synthesized water‐based cement [67]. It was patented in 2006 [68], but introduced as a product in 2008. The first product where the definition of bioceramic is mentioned is BioAggragate [68]. It is an improved form of white MTA. It contains tricalcium silicate, dicalcium silicate, silicon dioxide, tantalum peroxide, calcium phosphate, and phosphorus [69]. But differently from white MTA, it is aluminum‐free and contains calcium phosphate monobasic, and tantalum pentoxide. While the former adjusts its hydrate setting, the latter works as a radiopacifer [70]. BioAggregate powder which contains bioceramic nanoparticles is mixed with BioA Liquid (deionized water) (Figure 3.4a) [5].

According to the manufacturer’s claims, it is a biocompatible material because of its aluminum‐free construction. Its working time is reported as at least 5 minutes. The mixture of powder and liquid composes a thick paste‐like structure which makes manipulation easier. Since all the materials in its contents are white, the color obtained after mixing adapts to the natural tooth color [5]. Because of the lack of bismuth oxide, no tooth discoloration is expected [69]. The radiopacity of BioAggregate is equal to 3.8 mm Al, meeting ISO standards [71].

BioAggregate is insoluble in tissue fluids and has antimicrobial features [72]. It is a nontoxic and biocompatible material which is shown by the deposition of hydroxyapatite [73]. When hydrated, tricalcium silicate produces calcium silicate hydrate and calcium hydroxide. Its calcium ion release is quite high and sustains it over a 28‐day period [69]. Mineralization, odontoblastic differentiation effect on human dental pulp cells, and antimicrobial activity against Enterococcus faecalis is comparable to MTA [73, 74]. Also, it showed similar cell viability with MTA [73] and Biodentine [74]. Its strength against acid is more than MTA [75]. On the other hand, its push‐out bond strength was reported lower than MTA and common failure mode was shown as cohesive [76].

3.2.4.2 Biodentine^TM

Biodentine^TM (Septodont, Saint‐Maur‐des‐Fosses, France) was released to the market in the beginning of 2009 by Septodont. It is developed with Active Biosilicate Technology™, which can purify the calcium silicate content by depriving it of aluminate and calcium silicate [77]. It is marketing in capsule/liquid form which ensures an easier clinical application (Figure 3.4b). This specific ratio allows the clinician to use optimally prepared material every time. The powder of Biodentine mainly contains tricalcium silicate (3Cao SiO₂) as the main core material and calcium carbonate (CaCO₃) as a filler. It also contains dicalcium silicate (second core material), iron oxide, and zirconium oxide which is responsible for the material’s radiopacity. The liquid of the material contains calcium chloride as an accelerator and hydrosoluble polymer as a water reducing agent. The powder in the capsule is mixed with the liquid for 30 seconds with a triturator at 4000–4200 rpm [78].

Biodentine mainly has superior physicochemical properties. The working time is about 1 minute and the setting time is between 9 and 12 minutes because of the calcium chloride in the liquid [79]. According to Grech et al. [80], these values only show the initial setting time and the final setting time can be up to 45 minutes. Thanks to its zirconium oxide content, it displays a radiopacity equivalent to 3.5 mm of aluminum which is over the minimum requirement of ISO standards [77].

The porosity of the material affects the amount of microleakage. Therefore, it is a very important factor that should be taken into consideration, especially in vital pulp treatments and regeneration procedures. Camilleri et al. [19] tested Biodentine both in a dry environment and immersed in a physiological solution. The results showed that microcracks and gaps were observed on the surface of Biodentine in dry conditions. However, lesser porosity was determined in the moisture environment [19]. Given this situation, it is important to consider the use of Biodentine in certain clinical situations.

In the literature, the Vickers microhardness value of Biodentine varies between 51 and 130 HV [19]. Considering the Vickers microhardness value of intact dentine varies between 60 and 90 HV [81], it could be concluded that Biodentine has similar mechanical behavior to human sound dentine.

According to the manufacturer’s reports, the resistance of Biodentine to the acidic environment is limited. However, in the phosphate‐containing saliva medium, Biodentine reportedly showed crystal deposition on its surface, which the company calls an “apatite‐like” structure, which may increase the material’s marginal sealing ability [77].

In the biologic aspect, Biodentine is a non‐genotoxic, bioactive, and biocompatible material [82]. It was shown that when Biodentine had direct contact with pulp, it induced proliferation, migration and adhesion of human dental pulp stem cells [83]. Besides this, it also has antimicrobial properties thanks to its high alkaline pH. It can induce odontoblastic differentiation and stimulate dentine bridge formation. Therefore, it can be used safely as a pulp capping material [84].

Biodentine has a wide range of applications in restorative, endodontics, and pedodontics practice. It is the only material in the market that can be used as a temporary enamel substitute up to six months [79]