systematic review
Clinical utility properties of new endodontic silicate-based sealers: a systematic review
Introduction: Filling in the root canal system plays a key role in the success of endodontic treatment. New silicate-based sealers have recently been introduced on the market to improve the properties of sealers used in these treatments. Before performing endodontic treatment, it is always useful to know the properties of different sealers.
Objectives: The aim of this study was to review the literature and compare the clinically useful properties of new silicate-based sealers with those of conventional epoxy resin-based cements.
Methods: After establishing the adapted research question, a literature review was carried out in two databases (Medline via Pubmed and Wiley Library via Cochrane Library) combining MeSH (Medical Subject Headings) and free terms. A manual electronic search was also performed. The clinically useful properties selected were discolouration, sealing capacity, radiopacity, setting time and solubility.
Results: Of the 224 potential studies obtained, 20 were selected for reading of the full text. Another 4 studies were selected after manual electronic searching of which 2 were excluded, leaving 22 studies for inclusion in the review. The following physical properties were analysed: 2 for tooth discolouration; 4 for sealing ability; 11 for radiopacity; 9 for setting time; and 12 for solubility; 9 of the articles evaluated several properties.
Conclusions: No differences in tooth discolouration were observed between silicate-based and resin sealers. No differences in sealing ability were observed in most of the studies consulted. All sealers analysed showed radiopacity values within the recommended standards. Both setting time and solubility depended on the type of sealer; with some of the silicate-based sealers having higher solubility than the resin-based.
After shaping and cleaning the route canal system, complete sealing is needed for success in endodontic treatment1 . The materials used regularly for sealing are gutta-percha and sealing cements2 . Sealing cements are substances capable of penetrating between the sealer material and root canals3 . There are different types on the market, however, despite having many of the properties described by Grossman, they do not have them all4 . They can be classified according to their main components5 : Zinc oxide eugenol, calcium hydroxide, glass ionomer, silicone, resin and bioceramic cements6 .
Currently, those composed of resins are used most, with the epoxy resin cement AH Plus™, being considered the Gold Standard3,7. However, this cement has a series of limitations, which are possible cytotoxicity, mutagenicity and inflammatory response8 . Another limitation is its lack of bioactive properties9 . Therefore, new types of sealant called bioceramic cements10 have recently arrived on the market. These cements are based on the biological properties of MTA11 and include calcium silicates, phosphates and hydroxide as well as zirconium oxide as a radiopacifier12. The development of bioceramic cements has been based on obtaining good biocompatibility; however, these cements must also have adequate physical properties4 .
One of the issues that has gained importance in recent years is aesthetics7 . The aesthetic result of root canal treatment is important, especially in the anterior region13, as some remains of sealant cement can be left behind, despite the access cavity being adequately prepared and cleaned with alcohol14. Sealing capacity is another property of new sealant cements considered important5 . The dimensional changes of the root canal system, and the lack of adhesion of gutta-percha, make a complete seal necessary to obtain. Thus, adaptation of the sealant cement is a factor that influences the microfiltration and reinfection of the root canal system15. Another property considered essential is radiopacity, as it means clinicians can distinguish between the materials used and adjacent anatomical structures16, as well as evaluate the quality of the root canal filling17.
Another physical property the clinician must take into account is setting time. Slow or incomplete setting can lead to greater tissue irritation18, while too short a setting time can reduce working time by complicating and interfering with the sealing process19. Therefore, the setting time must be long enough to allow easy handling, especially for sealing techniques that require more time20. Solubility is another property that has special relevance when evaluating sealant cements21. Dissolution of the sealant cement can interfere with the quality of the root canal treatment and trigger an inflammatory response of the periapical tissues21,22. There may also be a vacuum between the sealer material and the root canal, increasing infiltration over time21. Therefore, sealant cements have low solubility22.
It is important to know the physical properties of the different resin based cements on the market. The objective of this systematic review was to analyse the scientific evidence behind the different properties of clinical significance of silicate-based sealants – such as dental discoloration, sealing capacity, radiopacity, setting time and solubility – and compare them with conventional resin cements.
