Proerties and uses of MTA

Properties

Ø  ph initial 10.2 & rises to 12.5 when set

Ø  Highly alkaline

Ø  Setting Time is 2 hrs 45min

Ø  Compressive strength 40 mpa immediately

   & 70 mpa after 21days

Ø  MTA has calcium oxide which reacts with water to form calcium hydroxide

Ø  This causes formation of calcite crystals & & fibronectin

Ø  These act as initiating step for hard tissue barrier formation

Ø  Fibronectin promotes cellular adhesion & differentiation

Uses

Ø  Repair of perforation

Ø  Root end filling material

Ø  Pulp capping agent

Ø  Apexification

Ø  Apical third filling material

Ø  Obturating material 

Advances in material aspect MTA

Advances in material aspect

MTA

Ø  Mineral Trioxide Aggregate

Ø  Developed at Loma Linda University

Ø  By Dr. Mohammed Torabinejad

Ø  Initially developed as perforation repair & root end filling material .

Ø  Now finds wide application in endodontics

Material is
FDA approved & commercially available as
Pro Root MTA

Composition

Ø  Main molecules are calcium & phosphorous ions

Ø  Derived from components

   --tricalcium silicate ,

   --tricalcium aluminate ,

   --tricalcium oxide &

   --silicate oxide

Ø    Bismuth oxide imparts radio-opacity

Portland cements & MTA

Ø  Portland cements contain the same components as MTA except that MTA also contains bismuth oxide for radio-opacity 

APICAL THIRD FILLING , Calcium Hydroxide Apical Filling

APICAL THIRD FILLING

                                                               SimpliFill Obturation

Calcium Hydroxide Apical Filling.

Ø  Mainly used where the apexification is desired

Ø  It is thought to provoke the cementogenesis

Calcium-Phosphate Cement Obturation.

Ø  More recently, Harbert has suggested using tricalcium phosphate as an apical plug,much like dentin shavings and calcium hydroxide have been used

Ø  In testing the sealing ability of CPC when used as a root canal sealer-filler, the Paffenbarger group reported that in most of the specimens there was “no dye penetration into the filler-canal wall interface”

Ø  Two calcium phosphate compounds, one acidic and one basic, are unique in that when mixed with water they set into a hardened mass”—hydroxyapatite—the principal mineral in teeth and bones

Ø  Another possibility of using hydroxyapatite relates to the laser. A cross-linked collagen-hydroxyapatite mixture has been placed in the root canal and “melted” to place with a laser beam through a fiber optic.

Ø  Another possibility of using hydroxyapatite relates to the laser. A cross-linked collagen-hydroxyapatite mixture has been placed in the root canal and “melted” to place with a laser beam through a fiber optic.