## 4 Contemporary Sealers with Indications for the Treatment of Teeth with Periapical Lesions
### Bioceramic sealers
#### 4.3.1 Calcium Silicate-Based Sealers  
The most recent innovations in bioceramic sealers have come with the introduction of calcium silicate or MTA-based sealers. These materials have been characterized as biocompatible and promote the deposition of hydroxyapatite crystalline deposits [47]. Two different types of calcium silicate-based sealers have been introduced: one-component (iRoot SP, Endosequence BC, Total Fill BC, Endoseal, Well-Root ST) and two-component (MTA Fillapex, NeoMTAPlus, BioRoot RCS, ProRoot ES) materials. * **iRootSP sealer** iRoot SP sealer (Innovative Bioceramix, Vancouver, BC, Canada) is another newly introduced calcium silicate-based sealer with desirable properties such as apatite formation. Injectable Root Canal Sealer (iRoot(r) SP) was introduced in 2007 as a white, injectable, premixed, and ready-to-use hydraulic substance for permanent root canal closure. iRoot SP is a revolutionary next-generation bioceramic material that is user-friendly, non-toxic, aluminum-free, antibacterial, hydrophilic, and has exceptional sealing properties. The sealer is highly biocompatible even in cases of overfilling and an effective filling material for perigical bone regeneration [48,49]. The composition of the sealer is as follows: zirconium oxide, dicalcium silicate, tricalcium silicate, calcium phosphate monobasic, calcium hydroxide, filler, and thickening agents. \"Bioceramic\" is a new term for sealers classified as bioactive, bioinert, or biodegradable, depending on their interactions with surrounding tissues. iRoot(r) SP is also available as the private-label Endosequence BC Sealer, distributed by Brasseler USA [49]. The mechanism by which bioceramic sealers adhere to root dentin interfaces is as yet unknown. Nevertheless, the following mechanisms have been proposed for calcium silicate-based sealers: (i) the diffusion of sealer particles into dentin tubules; (ii) the infiltration of sealer particles into dentin; and (iii) the chemical reaction of the sealant with the dentin's moisture, leading to the formation of hydroxyapatite [42,43,44,45,46]. In their formulation, bioceramic products may contain alumina and zirconia, bioactive glass, calcium silicates, hydroxyapatite, and resorbable calcium phosphates [50]. These materials are generally biocomputable, innocuous, nonshrinking, and chemically stable within the biological environment. They can also form hydroxyapatite during the setting process, forming a bond between dentin and the filling material [51; 52]. * **Total Fill BC sealer** Total Fill() (FKG Dentaire, La Chaux-de-Fonds, Switzerland) is a pre-mixed biocre-ramic obtoration material that contains calcium silicates, zirconium oxide, tantalum oxide, calcium phosphate monobasic, and thickening agents. It is administered with a syringe for root canal sealing and either a syringe or a plaster for root restoration and retrograde obturations [53]. The setting time is 4 h. In very dry root canals, however, the setting time can exceed 10 h. The TotalFill setting time is contingent on moisture in the dentin tubules. Dentin inherently contains the quantity of moisture required to complete the setting reaction. Before situating the material, it is therefore optional to introduce moisture to the root canal [53]. * **MTA Fillapex** MTA Fillapex  
MTA Fillapex is a hybrid biocreamic sealer created by Angelus Londrina/Parana/Brazil, in 2010 based on MTA. The multimodal application of MTA required the incorporation of material additives into the original cement/radiopacifier composition in order to generate superior formulations [54; 55]. Supposedly, these additions improve the material's characteristics and functionality. In addition, the original Portland cement formulation was replaced with tricalcium silicate to eliminate the presence of an aluminum phase and trace elements. It combines the established benefits of MTA with the exceptional qualities of root canal obturation products.