Should You Be Using A “Bioactive Bioceramic” (MTA) In Your Practice?

Featured Article

Should You Be Using A “Bioactive Bioceramic” (MTA) In Your Practice?

Mark Binford - VP, New Product Development at Avalon Biomed

Bioactive Bioceramics – What Are They?

According to ISO 22317:2014, materials are bioactive when they form apatite in body fluids, including synthetic body fluid. By definition, a bioceramic is any ceramic used in vivo. Bioceramics are inert, but bioactive bioceramics induce the precipitation of hydroxyapatite in synthetic body fluids or in vivo. MTA is a bioactive bioceramic. With more and more dental products companies offering MTA-based cements, there are now a host of options to choose from. Having a fundamental understanding of what MTA

14 Dental Explorer | Four th Quar ter 2017

(mineral trioxide aggregate) is, and how different MTAs vary from one another, is important to making an informed decision on what to use.

MTA chemical composition All MTA-containing products, including those marketed as “bioactive bioceramics,” are formulated with tri/ dicalcium silicate (MTA) as the primary active ingredient and blended with various radiopaque powders (Table 1).

Products in the marketplace vary in their amounts of radiopaque powder, particle size distributions, and minor phases.

Table 1: Major phases, determined by X-ray diffraction Product brand name

Tri/dicalium silicate

Radiopaque*

Avalon Biomed Grey MTA Plus®

72

25

Avalon Biomed NeoMTA Plus®

72

25

Biodentine®

83

4

BioRoot™

63

37

EndoSequence® BP Root Repair

55

37

EndoSequence® Root Repair

59

33

EndoSequence® RRM

63

34

EndoSequence® Sealer

41

59

MedCem MTA®

70

ProRoot® MTA (white)

76

20

TheraCal®

78

17

* Bismuth oxide, barium zirconate, zirconia, and/or tantalite.

Table provided by Carolyn Primus, PhD

It is these variations in composition that affect properties such as setting time and handling characteristics. All MTA-type products are hydrophilic; they require water for setting. Calcium hydroxide is a reaction product, embedded in the cement matrix, as shown in this equation: 2Ca3SiO5 + 7H2O g 3CaO.2SiO2.4H2O + 3 Ca(OH)2 (1)

What makes some MTAs “stainproof”?

Some popular “white” MTA products do discolor over time because of their bismuth oxide content. The original MTAs, whether “grey” or “white,” all contained bismuth oxide. While bismuth oxide is a good radiopacifier, it darkens over time. If MTA containing bismuth oxide is used coronally it will eventually cause the tooth to turn dark grey, which is unacceptable to most patients. There are now MTAs that incorporate nonstaining radiopacifiers. The two most common alternatives are tantalum oxide and zirconia powder. While both are effective, tantalum oxide provides higher radiopacity at a lower concentration. In short, not all “white” MTAs are the same; especially if using the product coronally, it is important to choose one that is both “white” and non-staining.

Unlike calcium hydroxide alone, however, MTA forms a stable cement seal, providing a permanent seal to further reduce the risk of reinfection.

15

Easy to mix and dispense MTAs are now an option.

Newer manufacturers of MTA-based “bioactive bioceramics” have made great strides in the mixing, dispensing and handling of these materials. A chief complaint regarding the original MTAs that dominated the market for years is that they are difficult to mix and produce a “gritty slurry” that not only is difficult to place but often will not stay in place. Some newer, more expertly formulated products are not “sandy,” are easy to handle, and mix easily to any desired consistency from an “IRMlike” putty to a smooth sealer.

Isn’t setting time an issue with MTAs? With the original MTA formulas, this was absolutely an issue with any procedure that required a stable, wash-out resistant cement. Setting time for these original MTAs was long, taking from several hours up to more than a day, and handling properties were notoriously poor. New formulations

have now come to market that are washout resistant within 4 minutes after placement, and set within 15 minutes.

MTAs are now usable for multiple indications.

With all these advances in color stability, mixing, handling and setting time, newer MTAs are actually quite usable for a host of indications. From vital pulp therapy to perforation healing, apexification, root-end filling, obturation, and sealing, these new MTAs can now be one of your most effective, and most proven, “go-to” products.

So all of this comes at a price…Right?

Yes it does … a LOWER price! While some MTA products still cost up to $30 per dose, some of the newest and best formulations on the market actually cost under $5/dose.

As a result, the impressive benefits of these new bioactive bioceramic MTAs are now globally affordable and available to all patients.

Avalon Biomed, a division of NuSmile, LTD, is solely dedicated to the design and manufacture of MTA-based advanced bioceramics in the USA.

16 Dental Explorer | Four th Quar ter 2017