Balancing in total removable prosthesis

Balancing in total removable prosthesis

Definition :

Set of technical and therapeutic means intended to promote the bio-organic integration of the prosthesis, to restore the different physiological functions and to preserve the integrity of the remaining tissues.

Goals

Biomechanics:

Improve direct and indirect stability and retention, through the adequate distribution of functional loads over the entire support surface.

Neurophysiological:

Obtain exteroceptive and proprioceptive stabilization played by the paraprosthetic muscles.

Why balance?

Preserve tissue integrity.
Respect neurophysiological balance.
Rehabilitation of the functions of the masticatory system.
Technical inaccuracies.

Requirements :

Respect for occlusal anatomy: Preserve the convexity of the support cusps, Respect the compensation curves.
Preserve the DVO.
Allow for a harmonious distribution of occlusal loads.
Minor fixes.

How to balance?

*On articulator or in oral cavity?

Balancing on an articulator has the following advantages:

The intermaxillary RC is recorded only once;
The prostheses are stable and locked on the balancing models;
no saliva; better visibility.

*Prerequisites:

In the laboratory:

1- Making a mounting key:

Check the muffle setting.
Highlight any possible dental movements.
Replace the upper model on the articulator.

2-Creation of balancing models:

3-Creation of the double meshed base:

At the office:

1-Insertion control

2-Occlusion recording.

*Equilibration protocol:

Material :

Reminder :

Guide cusp (A).

Support cusp (G).

Balancing in total removable prosthesis

Principles of occlusal equilibration:

Preserve the DVO.
Never shorten a cusp tip.
Deepen the antagonist reception zone.
Respect the occlusion curves.
Maintain the secant power of the support cusps by preserving their initial reliefs.
In propulsion and laterality never eliminate a point of contact in relation to the occlusion in centric relation.
Limit the amount of grinding.

1st time: Centered relationship

The goal is to establish a cusp-embrasure relationship at the PM level and a cusp-fossa relationship at the molar level.

There should be no contact between the free edge of the mandibular incisors and canines and the lingual surface of the opposing teeth.

* Otherwise, the corrections are addressed to the free edges of the mandibular teeth, and can also be addressed to the lingual faces of the maxillary teeth.

Result :

Establishment of occlusal contacts distributed over all the posterior teeth.
Contact of the incisal rod with the plate.
No previous contact.

2 times: Eccentric contacts

The goal is to obtain generalized contacts or triped contacts.

a)-Laterality

Ruler :

Non-working laterality

Rule #1

Never eliminate a contact point related to centric relation occlusion.

Rule #2

The corrections always concern the internal slopes of the mandibular vestibular cusps , in a disto-vestibular direction.

Working laterality (Fig. 15)

Rule #1

Never eliminate a contact point related to centric relation occlusion.

Rule #2

The corrections concern the secondary cusps, at the level of the upper mesial and lower distal internal slopes.

Desired result:
The incisal rod slides smoothly on the incisal table.

b)-Propulsion:

Ruler :

Rule #1

Never eliminate a contact point related to centric relation occlusion.

Rule #2

In propulsion, at the level of the posterior sectors, the corrections concern the upper distal and lower mesial cusp slopes, preferably at the expense of the secondary cusps. These corrections continue until the incisal rod slides smoothly on the incisal table.

Rule #3

In propulsion, at the level of the anterior sectors:

*correct the palatal surface of the upper anterior teeth if, with the free edges in contact, the posterior teeth are in contact; *correct the mandibular or maxillary free edges if, with the free edges in contact, no contact between the posterior teeth occurs.

Desired result:

The goal is to obtain generalized contacts or triped contacts.

Incisal end-to-end contact.
The incisal rod should slide smoothly over the incisal plate.

b)-Retropulsion:

Grinding type:

Mesialupper:

Upper mesial slope “MS”;

Distal lower:

Lower distal slope “DI”.

Finishing corrections. Running-in.

Conclusion :

Occlusal equilibration is a key step in prosthetic delivery that should not be underestimated and even less neglected.

Its undeniable role in the sustainability and preservation of the integrity of the underlying mucosal and bone tissues no longer needs to be demonstrated.

Balancing in total removable prosthesis