Theracal lc: A boon to dentistry

TheraCal LC, the focus of this article, is a material that creates a new category of resin-modified calcium silicates (RMCS). It is a light-cured, resin-based, and highly radiopaque liner designed to release calcium to promote hard-tissue formation, and is indicated for use under direct restorative materials as a replacement to calcium hydroxide and other calcium silicate-based materials, glass ionomers, eugenol-based sedative materials, and pulp capping restoratives. TheraCal LC exhibits several properties to help maintain ideal hard-tissue health and to reduce the incidence of postoperative sensitivity. This article is aimed to review the composition, method of application, setting reaction, properties and uses of TheraCal LC. TheraCal LC is interesting and promising product, which have the potential of creating major contributions to maintaining pulp vitality.

Influence of Natural Polysaccharides on Properties of the Biomicroconcrete-Type Bioceramics

In this paper, novel hybrid biomicroconcrete-type composites were developed and investigated. The solid phase of materials consisted of a highly reactive α -tricalcium phosphate (α-TCP) powder, hybrid hydroxyapatite-chitosan (Hap-CTS) material in the form of powder and granules (as aggregates), and the polysaccharides sodium alginate (SA) or hydroxypropyl methylcellulose (HPMC). The liquid/gel phase in the studied materials constituted a citrus pectin gel. The influence of SA or HPMC on the setting reaction, microstructure, mechanical as well as biological properties of biomicroconcretes was investigated. Studies revealed that manufactured cement pastes were characterized by high plasticity and cohesion. The dual setting system of developed biomicroconcretes, achieved through α-TCP setting reaction and polymer crosslinking, resulted in a higher compressive strength. Material with the highest content of sodium alginate possessed the highest mechanical strength (~17 MPa), whereas the addition of hydroxypropyl methylcellulose led to a subtle compressive strength decrease. The obtained biomicroconcretes were chemically stable and characterized by a high bioactive potential. The novel biomaterials with favorable physicochemical and biological properties can be prosperous materials for filling bone tissue defects of any shape and size.

A influência do tamanho de partícula na reação de presa de cimentos de silicate de cálcio produzidos por sol-gel

Introduction: This study aims to analyze the influence of particles size of sol-gel derived calcium silicate particles in the setting reaction of bioactive endodontic cements. Materials and Methods: Sol-gel derived calcium silicate particles were synthesized and sieved to separate the particles in different sizes: CS400, CS200, and CS100. A commercial MTA (Control) was used as control. The particle size and the specific surface area were assessed by laser diffraction and nitrogen adsorption. The cements were prepared with water as the liquid for the reaction. The setting time was conducted according to ISO 6876, and the setting kinetics was analyzed by Fourier transformed infrared spectroscopy (FTIR) at different time points between 120s to 72h. Results: The particle size varied from 9.45µm (CS400 ) to 31.01 (Control). The higher specific surface area valuer reached 15.14g/cm2 in the CS400. The smallest particle sizes, the higher specific surface area, and the lowest setting time were found for CS400 (p < 0.05). Control presented the highest setting time (p < 0.05). The FTIR analyses showed the differences in materials structure over time, with faster hydration and crystallization for CS400. The setting kinetics was slower for Control even when compared to a sol-gel derived group with similar particle size. Conclusion: The route of synthesis and the particle size influences the setting reaction of calcium silicate-based cements. The reduction of particle size for sol-gel derived calcium silicates lead to the acceleration of the setting reaction of the produced bioactive endodontic cement.

Effect of Different Granular Size on the Properties of Porous β-Tricalcium Phosphate Foam Granular Cements

Porous β-tricalcium phosphate (β-TCP) foam granular cements was obtained by exposing different range size of β-TCP foam granular (300-600 μm and 600-1000 μm) with 1.4 mol/L of saturated acidic calcium phosphate solution at various setting reaction times. It was found that large amount of dicalcium phosphate dihydrate (DCPD) was formed in the set specimens after exposing small size of β-TCP foam granular with saturated acidic calcium phosphate solution. Morphological observation shows that the bridging of DCPD platelet-like crystals between β-TCP foam granular surfaces were detected as early as 10 mins after exposing 300-600 μm of β-TCP foam granules with saturated acidic calcium phosphate solution. In fact, the amount of DCPD formed in the specimens obtained from small size of β-TCP foam granules is higher than large sized foam granules. These results demonstrated that small size of β-TCP foam granules induced fast setting reaction of β-TCP foam granules to produce porous β-TCP foam granular cements.