Although both glass-ionomer cements and calcium-hydroxide materials have been recommended for deep-cavity lining, their performance is less than desirable when in direct contact with pulpal tissues. MTA is difficult to place and requires a setting time that is clinically much too long.
A definitive 2004 in vivo Brazilian study using non-human primates tested several materials, including a light-cured resin-based Portland-like cement, which was shown to perform significantly better (more frequent hard-tissue bridge formation, less pulpal necrosis) than the other materials. The encouraging results achieved with this new material led to the development of TheraCal LC, introduced by Bisco in late 2011. TheraCal LC is a light-cured, resin-modified calcium-silicate-filled radiopaque liner for direct and indirect pulp capping as well as for protective lining under composites, amalgams, cements, and other base materials. An alternative to calcium hydroxide, glass ionomer, RMGI, IRM/ZOE, and other materials, TheraCal LC creates a barrier that protects the dental pulpal complex.
Because of its thixotropic properties, TheraCal LC?s precise placement allows its use in all deep cavity preparations. And its light-cured command set permits immediate placement of restorative material. The proprietary hydrophilic resin formulation creates a stable and durable liner. In addition, the alkaline pH and calcium availability maintains its biocompatibility and antibacterial qualities. Applying TheraCal LC is so simple because it adheres well to a moist substrate. A small increment can be extruded from the syringe and teased into the deepest portion of preparations or onto any area of pulpal exposure. Additionally, Thera- Cal LC requires only a very thin coat to be effective, stays in place after light-curing, and is not displaced by acid etching.
The appearance of TheraCal LC is similar to enamel for natural looking esthetics. To date, none of my patients treated with TheraCal LC have complained of any sensitivity or other complications. This is, of course, anecdotal information and large, well-controlled clinical trials will be necessary to ascertain the long-term benefits. In my experience, Thera-Cal LC may be successfully used as part of any dental adhesive regimen used in minimally invasive dentistry.