BioRoot® RCS, a Reliable Bioceramic Material for Root Canal Obturation

Introduction

During the treatment of root canals it is practically impossible to obtain an environment completely free of bacteria (Markus Haapasalo, Shen, Qian, & Gao, 2010); considering this fact, the root obturation procedure must contain the remaining microorganisms, keeping them deprived of nutrients and of an environment capable of reactivating their metabolism and growth (Simon, 2016; Siqueira, Araujo, & García, 1997). The majority of modern obturation techniques involve the use of gutta-percha combined with sealing cement; the latter is used with a view to filling in the interface between the root dentin and the gutta-percha. Cement fluidity is an important factor in ensuring that it will reach the areas of the canal that cannot be accessed with root-shaping instruments, but are receptive to chemical disinfection processes applied by means of the various irrigation techniques (Siqueira, Rocas, Favieri, & Lima, 2000).

It is advisable to use a minimal amount of sealing cement in proportion to the amount of guttapercha used when resin-, zinc oxide-eugenol-, or calcium hydroxide-based cements are to be used since the use of substantial amounts of cement generates the possibility of degradation and leakage, which may lead to bacterial recontamination, and thus causing over time the failure of the endodontic treatment (Simon, 2016). Of the obturation techniques discussed in the literature, single-cone obturation is one of the most sensitive to post-operative leakage since the gutta-percha cones used with the instrumentation system are not perfectly compatible with the final shape of the root canal (Schäfer, Köster, & Bürklein, 2013). Due to the variability of gutta-percha cones and the irregularities specific to root canal systems, the sealing cement used must be physically stable, must provide good apical sealing, and must have the ability to set in the presence of the moisture present in dentin and periradicular tissues.

Single-cone obturation is one of the simplest and quickest methods to use but is very questionable if applied with non-bioceramic cements, since the presence of large amounts of sealant in the obturation may cause leakage problems over time (Simon, 2016). Bioceramic cements are an interesting option for the use of the single-cone technique; their physical characteristics render them capable of providing a stable three-dimensional seal in the necessary time frame (Daculsi, Laboux, Malard, & Weiss, 2003), all without the need for compaction procedures, whether warm or cold. These materials are able to set in humid environments; this point has major relevance considering the fact that dentin has a moisture content of approximately 20%, and that work in moisture-saturated environments is a constant in the dental profession (K. Koch, Brave, & Nasseh, 2010).

Bioceramic cements are divided into three basic groups.

1. Bioinert high-strength cements;
2. Bioactive cements that form chemical bonds with mineralized tissue;
3. Biodegradable materials that integrate actively with the body’s metabolic processes (K. Koch & Brave, 2009).

Due to their high stability and sealing properties, bioceramic cements can be used in combination with gutta-percha as part of a single-cone technique, or directly inside the root canal to seal their entire length. Though bioceramic cement may function as an obturation material, it is advisable to use a gutta-percha cone to convey it to the inside of the canal and hold it in position at the working length or one millimeter short, leaving a route for retreatment if necessary in the future. This last procedure would be a real challenge for the operator if no access route were available for re-treatment.

The single-cone obturation technique can be used safely in combination with bioceramic cements, due to their previously mentioned physical and dimensional stability, good sealing properties, antibacterial potential, biocompatibility, and bioactivity capable of stimulating periapical tissue repair (Trope & Debelian, 2014). BioRoot^® RCS is a relatively new* bioceramic cement based on tri-calcium silicate, zirconium oxide as a biocompatible radio-opacifying mate-rial and a hydrophilic polymer to improve its adhesion properties; the liquid mostly contains water with calcium chloride as a setting modifier (Nakov et al., 2015). The working time is approximately 15 minutes and the total setting time is 4 hours within the root canal (Simon, 2016). Next, we present a clinical case performed using BioRoot^® RCS as a root-filling cement.

Read the Clinical Case