complex amalgam - mashhad.ircme.ir

What we learn today

1. What is complex amalgam

2. When we use it

3. Technical review

4. Pros. And cons.

5. Workshop videos:

Prefabricated Post placement

Matrix placement

Amalgam insertion

Carving

Finishing and polishing

Preparation and Filling Dr. Hossein Chalakinia

Definition and Indication

Definition and Indication

Simple: when restoring one surface of the tooth.

Compound: when restoring two surface of the tooth.

Complex: When restoring three surfaces or one or more than one lost cusps.

Complex amalgams may be used as

(1) definitive (final) restorations,

(2) foundations,

(3) control restorations in teeth that have a questionable pulpal or periodontal prognosis, or control restorations in teeth with acute or severe caries lesions.

Contraindication

The complex amalgam restoration may be contraindicated if the

tooth cannot be restored properly with direct restoration because of

anatomic or functional considerations (or both).

The complex amalgam restoration also may be contraindicated if

the area to be restored has esthetic importance for the patient.

Advantages and Disadvantages

Conservation of Tooth Structure

Appointment Time

Resistance and Retention Forms

Reduced Cost

Disadvantages:

Tooth Anatomy

Resistance Form

Preparation for Cusp Coverage

When the facial or lingual extension exceeds two thirds the distance

from a primary fissure toward the cusp tip

when the faciolingual extension of the occlusal preparation

exceeds two thirds the distance between the facial and lingual

cusp tips.

When width to height is less than 1, cusp coverage is considered.

For cusps prone to fracture, coverage reduces the risk of fracture

and extends the life of the restoration.

Complex amalgam restorations that cover one or more cusps have

documented longevity of 72% after 15 years.

Mashhad Dental School

Complex Amalgam Restoration

for

Vital and non-Vital

Differences:

1- indications

2- techniques

Vital teeth

Vital Teeth

Retention form

Indications

Survival

Secondary Retention Forms

Slots, Coves and Lockes

When loss of vertical coronal height is approximately 2 to 4 mm.

Slots are placed in the gingival floor of a preparation with a No. 330 bur

Should be prepared 1 mm wide and 1 mm deep

Should be placed in the line-angle areas of the tooth,

Should be placed 2 to 4 mm in length and be positioned 0.5 to 1 mm inside the DEJ.

Pin-Retained Amalgam Restoration

When severe carious destruction or cusp fracture has resulted in the

loss of 4 mm or more of vertical coronal height.

Proximal Box Retention Group

Fracture and lost pins

Tooth #15

Deep distal Caries

No symptoms

Normal vitality tests

• Treatment:

• Indirect pulp cap

• Complex Amalgam buil-up

Dr. Hossein Chalakinia

Non-Vital Tooth

Non-Vital Teeth

Direct or in-Direct?

Are in-direct restorations the only solution?

What are the advantages or dis-advantages?

The purpose of this article was to determine restorative choices of dentists for personal

molars and estimate restoration longevity.

Material and methods. Approximately 12,000 e-mails asking to access the website

were sent to dentists' addresses randomly selected from a commercial database.

Results. 757 valid replies provided information for 6,034 teeth.

Restorations with more than 20 years longevity included:

1. Amalgam restorations (58%),

2. Gold inlays/onlays (48%)

3. Crowns (23%).

Conclusions. Most dentists have not replaced traditional metallic restorations with

esthetic alternatives. Dentists still choose nonesthetic options for significant numbers of

their own restorations.

Personal Opinion

Posterior teeth which received root canal treatment:

Access only:

Direct Restoration.

Molars with one lost marginal ridge:

Reduction of 2 adjacent cusps => Direct restoration

Molars with 2 lost marginal ridges:

Direct foundation (most cases) => in-Direct retoration

Pulp Chamber Retention of Foundations

When the pulp chamber height is 2 mm or less:

Additional extension of 2 to 4 mm into the root canal space is

recommended. (amalgapin)

pulp chamber height is 2 to 4 mm or less:

A pre-fabricated intra-canal post is recommended

pulp chamber height is 4 to 6 mm or higher:

no advantage is gained from additional extension into the root canal

space.

FOUNDATION

Ferrule

The resistance form against forces that otherwise may cause tooth fracture is

improved by gingival extension of the crown preparation approximately 2 mm

beyond the foundation onto sound tooth structure to establish the necessary

ferrule once the indirect restoration is in place.

INDIRECT RESTORATION

Fatigue Test!

Teeth without a ferrule withstood only 212 load cycles;

the presence of a 0.5-mm ferrule raised the mean failure to 155,137load cycles.

teeth with a 1.0-mm ferrule survived the testing to completion at 250,000 cycles.

While it is ideal to have 360 degrees of circumferential axial wall dentin, when there are only partial walls remaining, the location of those walls may affect the prognosis of the restored tooth.

As might be predicted by the functional forces applied, the presence of a palatal wall of dentin was found to be critical to the ability of anterior teeth restored with FRC posts to resist crown dislodgment.

Clinical Cases

Clinical Notes

Pre-Fabricate Posts

Types: Fiber reinforced, Brass, Titanium

Indications: Anterior or Posterior, Cores

Cementation: Conventional or Bonded

Preparations

Root Canal

Prefabricated Posts

Core retention

Canal preparation

Which root canal

How deep

Armamentarium for canal preparation

Location and Orientaion


Radiographic Checking


Amalgam RestorationPREPARATIONS AND ANATOMICAL CARVING

Preparation and Filling Dr. Hossein Chalakinia Baseline and Final Photo

Cusp Reduction

Amalgam Filling

Armamentarium

Matrix Holder and Barton Matrix

Dental Anatomy

Importance of

Form and Anatomy

Harmony of form is a prerequisite for harmony of function, and it is necessary to

have a working knowledge of how the two interrelate.

Every aspect of each tooth’s position and contour can be determined on the basis

of its harmony with functional requirements.

Important point to grasp at this time is that every part of the masticatory system has

an understandable reason for its position, contour, and alignment.

If any anatomic component is not in harmony with the rest of the masticatory

system, some part or all of the system must adapt to regain equilibrium.

Peter E. Dawson

3 Steps for perfect amalgam carving

1. shape the outer or peripheral slopes:

In this step you will define the outline of the restoration and its outer limit of occlusal table.

2. Mark and carve fissures and pits:

After defining the restoration outer limit, with carving the ain fissures and pits you can facilitate the forming of the inner slopes.

3. Shape the inner slopes ending to the fissures and pits:

starting point of a inner slope is the limits of the occlusal table and its ending is in the occlusal fissures which both was defined in previous steps.

Outline

Anatomy

Outline

Anatomy

Occlusal Table

Outline

Anatomy

Armamentarium for Amalgam

Polishing

Any Questions ?

Guilan

Guilan

complex amalgam - mashhad.ircme.ir

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