Читать книгу Endodontic Materials in Clinical Practice - Группа авторов - Страница 40

In an attempt to overcome the long setting time of HCSCs, command‐set light‐cured HCSCs have been developed. TheraCal LC (Bisco, Schaumburg, IL, USA) is one of the most researched. It consists of a mixture of Portland cement, strontium glass, fumed silica, barium‐based radiopacifier, and a light‐activated resin made up of Bis‐GMA and polyethylene glycol dimethacrylate [179]. Although it is claimed to be an HCSC, the reaction of the Portland cement component requires the imbibition of fluids from its surroundings, which may be limited [180]. TheraCal cures through photopolymerization, and the water‐based reaction is slow as the liquid required for the setting of the cement depends on the porosity of the resin. A number of organic components are not declared on the material safety data sheet [181]. Leaching of calcium hydroxide is negligible [182] or significantly less than that of other CSCs [183]. The alkaline pH of TheraCal is similar to that of Dycal [184] and significantly lower than that of ProRoot MTA at both short‐ and longer‐term intervals [185].

Several in vitro studies have been carried out comparing TheraCal to other VPT agents. It has been demonstrated to be cytotoxic with pulp cells [186, 187], and it shows more significant inflammation and less bioactive potential than Biodentine [187]. The authors of the latter study even suggested it should not be considered a candidate for direct interfacing with the pulp.

TheraCal does not perform as well as conventional water‐based HCSCs when interfacing with the pulp itself [188]. In a study of partial pulpotomies in dogs, it induced pulp inflammation in 90% of cases, compared with 18% of those treated with ProRoot MTA [188]. A histological study of partial pulpotomy of third molars in humans compared the use of Theracal, ProRoot MTA, and Biodentine. TheraCal treatment resulted in pulp disorganization beneath the material in 66.67% of cases and of the entire pulp in 22.2%. Discontinued dentinal bridge was noted in most cases treated, and the authors stated that Biodentine and ProRoot MTA were more reliable for long‐term protection of dental pulp [189].

Based on the limited research to date, it does seem that TheraCal is a poor candidate for VPT when directly interfacing with the exposed dental pulp. It may be that it is more suitable for use as an indirect pulp‐capping agent, but there is scant evidence for this indication.