Mix and Place MTA

Powder to Cement Ratio

The general recommended ratio of water to cement ratio in the concrete industry is 0.4. Although the instructions for use for MTA requests 1 part water to 3 parts cement, which suggests a ratio of 0.33, the MTA is actually 2.6 parts cement with 0.4 parts inert bismuth oxide. Therefore, the effective cement to water ratio is 0.42, similar to the suggested ratio from the concrete industry. Thus, clinicians should follow the manufacturer’s suggested mixing ratio

Water Substitution

Admixture Type

Industry Examples

Dentistry Examples


CaCl2, NaCl

CaCl2 - can be purchased from compounding chemists and prepackaged with BiodentineTM




Sugars, carbohydrate derivatives, some salts

Local anaesthetic solutions

Chlorhexidine gluconate

Methylcellulose, Carboxymethylcelluose, polypropylene glycol, glycerine (found in endodontic dressings)

Water Reducing Agents

Hydroxylated carboxylic acids, Lignosulfonic acids

Pre-packaged with BiodentineTM

Placing MTA

After mixing MTA in a dappens dish or mixing pad, there are various ways to place mineral trioxide aggregate.

Standard restorative and endodontic hand instruments can be used to apply the MTA into a tooth defect. 

MTA Carriers (MAP System)

Lee Block

A Lee block can be used to assist in the collection of MTA onto the instruments.

Further detail can be found from reading this scientific article 

or viewing this video 

Alternatively you can use amalgam carriers, which you may find excessively large for most uses.

MTA carriers exist, which are similar to amalgam carriers, albeit, much smaller and more appropriate for the uses of MTA.