Fig. 1

Vectorial decomposition of the compaction force between two inclined planes. Plugger, compaction force that can be decomposed into tangential force (t) and normal force (n). r, reaction force; f, friction force; R, resulting force.

Fig. 2

PrexoM plugger: One side of the plugger has the drop shape design with rounded angles at the edges. The reverse shape continues along the body and at the curvature level decreases of 1/3 compared to the tip diameter (0.75mm). In this way during MTA adaptation the tactile sensation transferred to the operator is ideal in order to understand material consistency and if it is too dry the plugger will flex at curvature level.

Fig. 3

This clinical case shows two upper incisors with apical lesion and different apical sizes. The treatment plan consists into the retreatment of 2.1 and treatment af 2.1. In both cases MTA apical plug represents the ideal treatment technique.

Clinical video of PrexoM in action for compaction of MTA in both teeth. 4mm of MTA has been placed and immediately after the backfilling made with GP.

Fig. 4

X-rays of the previous case

Another retreatment case of 2.1. PrexoM has been used for resorbable matrix application beyond the apex and for MTA application.


A versatile instrument useful for different purposes is exactly what a clinician needs. PrexoM is a plugger with an unique shape able to transfer to the clinician’s fingers all the informations needed for managing properly a tricky material like MTA.


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  2. Stephen Cohen, Kenneth M. Hargreaves. Pathways of the pulp, St Louis, Missouri, Mosby 2006, 622.
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  4. Hachmeister DR, Schindler WG, Walker WA 3rd, Thomas DD.The sealing ability and retention characteristics of mineral trioxide aggregate in a model of apexification. J Endod. 2002 May; 28(5):386-90.
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