Successful outcomes of root canal treatment, in addition to a multitude of factors, also depends on the prevention of reinfection of the root canal space. The ultimate goal of root canal treatment is prevention or healing of apical periodontitis. The use of biologically active materials to seal root canal systems has been extensively proposed in contemporary endodontics to realise this goal. There are several commercial formulations of bioceramics available based on minor variations in composition which could have potentially important changes in properties in the clinical situation. This narrative review serves to provide brief information on the different formulations of bioactive ceramics that are available to a dentist.
Gray MTA Plus/ MTA Plus is a powder and liquid/ gel system. The powder consists of fine inorganic substance similar to that of ProRoot MTA. Liquid or gel may be used for cavity liner/base, pulp capping, pulpotomy, root apexification,resorption/perforation repair or root-end filling material. The water-based gel (with water soluble thickening agents and polymer) imparts washout resistance and faster setting, which the liquid does not. The manufacturer recommends mixing the powder with gel into a syrupy, stringy consistency when used as a root canal sealer during obturation. NeoMTA Plus is a powder-gel system. The powder components are an extremely fine powder primarily tricalcium and dicalcium silicate, quite similar to that of white ProRoot MTA, but contains no bismuth oxide in order to prevent tooth staining. Tantalum oxide is used as the radiopacifier.
The manufacturer claims that this material achieves washout resistance in less than three minutes (MTA Plus is about five minutes), thus allowing continuation of the restorative procedure. Also it has a 20-minute working time and a 50-minute setting time when mixing to a putty consistency. Thus, the setting time of both MTA Plus and NeoMTA Plus are depending on the consistency of the mixed material. The setting time of MTA Plus was found retarded when in contact with fluids; about 128 minutes in dry condition and about 1,052 minutes in contact with physiological solution. While the hydration of the core material was not affected by contact with the different solutions but the periphery exhibited microcracking, leaching of calcium hydroxide, partial decalcification of calcium silicate hydrate, and interaction with a physiological solution resulted in inhibition of hydration.The compressive strength was significantly lower when MTA Plus mixed with liquid was exposed to the biological fluid compared with saline. However the material mixed with gel was not affected in this condition.