Endodontic sealer

Orstavik D, Hongslo JK. 1985. Mutagenicity of endodontic sealers. Biomaterials 6 129-132. 

On the other hand, the new material known commercially as Biodentine is much more promising [61,69]. It is a hydraulic cement manufactnred by the French company Septodont and consisting mainly of tricalcinm silicate [70]. In this it resembles the endodontic sealer Mineral Trioxide Aggregate, MTA, thongh it has a different... 

The essential features of some of them have already been described in other chapters, and these details are not repeated. Rather, what follows emphasizes the application of these materials as endodontic sealers. 

Zinc oxide-eugenol is a somewhat old-fashioned material, but it is widely used as an endodontic sealer [18]. It has relatively poor mechanical properties, but is easy to use in the dental clinic [19] and outcomes are good, which explains its continuing popularity. When set, it is biocompatible towards dental hard tissues, though it is cytotoxic towards soft tissues [20]. Zinc oxide-eugenol is susceptible to hydrolysis, which causes the material to decompose and release eugenol. It is this latter substance which is responsible for the cement s adverse effects on soft tissues, but which also makes the material bactericidal. 

Overall, despite not having completely ideal properties as sealing materials, zinc oxide-eugenol is an effective material. Its many years of satisfactory clinical service demonstrate this, and outcomes with it are generally good. There is little current research on zinc oxide-eugenol endodontic sealers, bnt this is a reflection on the fact that it is a mature material with a proven track record. It ranains one of the most widely used materials for endodontic sealing [18], and is likely to remain so for the foreseeable future. 

Leakage around calcium hydroxide sealers has been studied experimentally, and findings have generally been satisfactory [34-36]. However, there have been some adverse reports [37], and these variations have been attributed to crucial differences in experimental methods [38]. Leakage appears to be related to both the solubility of the material and the questionable adhesion to both the dentine walls and the gutta percha points. The calcium hydroxide sealer Apexit, for example, was found to have a high solubility when set compared with other types of endodontic sealer [39] and, in some studies, sealer particles have been found to occur with the tissues at a considerable distance from the sample [40,41],... 

The physical properties of calcium hydroxide materials are acceptable for their use as endodontic sealers. They flow well in their unset state, so they can reach and seal the apical foramen of the affected tooth, and also adapt to the shape of any irregularities of the dentinal wall. 

Overall, calcium hydroxide materials appear satisfactory as endodontic sealers in clinical service [47,48], though they are not outstanding in this application [30]. Established brands continue to be made available for practitioners, and clearly find favour with certain members of the profession. They must be... 

Since the launch of Ketac Endo, other glass-ionomer products for use as endodontic sealers have appeared on the market. They typically have reasonable physical properties [50,52], certainly better than those of zinc oxide-eugenol canents and they are less susceptible to hydrolytic degradation. 

Glass-ionomers are known to have strong anti-bacterial properties when newly placed [57], a feature which is attributed to the combined effects of their low early pH and their ability to release fluoride in an early burst shortly after forming [58]. These effects have been confirmed for glass-ionomer endodontic sealers [59], but anti-bacterial effects were transient, and had disappeared after 24h. This contrasts with zinc oxide-eugenol canent, which has been shown to maintain its anti-bacterial... 

Silicone-based endodontic sealers have to be mixed immediately prior to use [62,63], and this is done using a mechanical delivery system that ensures complete mixing of both pastes without the incorporation of air. Also present in one of the pastes is a trace of platinum to act as catalyst for the setting reaction. Setting involves pendant unsaturated groups on one of the polymer chains reacting with a hydrogen atom attached directly to a silicon atom (Fig. 10.4). The reaction results in cross-links between the polysiloxane chains, and these cause the material to set to a resilient rubbery solid [13]. 

Silicone endodontic sealers are formulated with very small particle size particles of zirconium oxide. This means that the unset silicone paste is able to achieve very thin film thickness, typically of the order of 5 pm. This ensures good flow into surface irregularities and also good adaption to the walls of the root canal. 

Silicone endodontic sealers in their set state are insoluble materials with good dimensional stability [62,63]. They undergo a slight expansion on setting, which... 

Epoxy resin-based materials are available for use as endodontic sealers [64], They set by a ring-opening polymerization reaction between hexamethylene tetratramine (Fig. 10.5), which is part of the powder component, and iiw-phenol resin monomer, which comprises the liquid component [13]. In addition to the reactive molecule, the powder contains bismuth oxide (50%) to impart radiopacity and titanium dioxide (5%) as a pigment. The powder also contains silver particles (10%) to make the set material anti-bacterial. 

The epoxy sealer AH26 Plus has been shown to have reasonable anti-bacterial properties [43]. In a comparative study of several different types of endodontic sealer, it was found to be as effective as Grossman s sealer in reducing the number of cultivable cells of Enterococcus faecalis. By contrast, the calcium hydroxide sealers Apexit and Sealapex were not effective at aU in reducing the number of these cells. 

Both AH26 and AH26 Plus are epoxy-based endodontic sealers that have been used for some years. They set hard, making them difficult to remove, but despite this, they remain in use and overall their properties appear acceptable if not ideal for this application. 

Over the years, a number of brands of this type of endodontic sealer have become available [75]. In recent years, there has been considerable interest in two brands, which have been widely studied. These are EndoREZ (Ultradent Products, Utah) and Epiphany (Penton Clinical, Connecticut), though other materials of this type are also discussed in recent publications [76]. The brand Epiphany has been designed specifically to be used in conjunction with the polycaprolactone endodontic points marketed under the brand name Resilon. The good adhesion obtained between the resin and these points has led to the suggestion that this system may be capable of behaving effectively as a monoblock [75], though experimental results do not really support this concept. 

There have been several smdies of the biological effects of resin-based endodontic sealers [82-85]. As with other types of endodontic sealer, adverse reactions are... 

These biological findings suggest that these resin-based endodontic sealers are acceptable for clinical use, a result that has been confirmed by clinical evaluations [86-88]. In one 5-year smdy involving 129 patients, results showed that root canals were adequately filled in 76.66% of cases (92) and were short in 10.83% (13) of cases. In 15 cases (12.50%), there was evidence of slight resorption of the sealer at the apex within the lumen of the root canal. These clinical results show that resin-based sealers compare well with sealers based on other types of material, and that they are satisfactory for use in endodontics [48,89],... 

I. Soares, F. Goldberg, E. Massone, I.M. Soares, Periapical tissue response to two calcium hydroxide containing endodontic sealers, J. Endod. 16 (1990) 166-169. 

Z. Fuss, E. Weiss, M. Shalhav, Antimicrobial activity of calcium hydroxide containing endodontic sealers in Enterococcus faecalis in vitro, Int. Endod. J. 30 (1997) 397 02. 

G. Kayoglu, H. Erten, T. Alacam, D. 0rstavik, Short-term antibacterial activity of endodontic sealers to Enterococcus faecalis, Int. Endod. J. 38 (2005) 483-488. 

A. Abdulkader, R. Guduid, E. Saunders, The antimicrobial activity of endodontic sealers to anaerobic bacteria, Int. Endod. J. 29 (1996) 280-283. 

N. Allan, M. WUhams, M. Schaeffer, Setting times for endodontic sealers under clinical usage and in vitro conditions, J. Endod. 27 (2001) 421-423. 

M. Partovi, A. Al-Havvaz, B. Soleimani, In vitro computer analysis of crown discoloration from commonly used endodontic sealers, Aust. Endod. J. 32 (2006) 116-119. 

D. 0rstavik, K. Kerekes, H. Eriksen, Chnical performance of three endodontic sealers,... 

R.A. Buck, Glass ionomer endodontic sealers - literature review, Gen. Dent. 50 (2002) 365-368. 

M. Shalhav, Z. Fuss, E.I. Weiss, In vitro antibacterial activity of a glass ionomer endodontic sealer, J. Endod. 23 (1997) 616-619. 

H. Singh, S. Markan, M. Kaur, G. Gupta, Endodontic sealers current concepts and comparative analysis, Dent. Open J. 2 (2015) 32-37. 

D. 0rstavik, Weight loss of endodontic sealers, cements and pastes in water, Scand. J. Dent. Res. 91 (1983) 316-319. 

M.R. Leonardo, L.A. Bezerra da Silva, M.T. Filho, R. Santana da Silva, Release of formaldehyde by 4 endodontic sealers. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod. 88 (1999) 221-225. 

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