Quality Resource Guide

Posterior Composites 5th Edition

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it allows for the most conservative restorative

approach. If one remembers that dental caries is

still one of the most prevalent human diseases

in both developed and developing countries, the

relevance of the posterior composite technique

becomes evident. Composites are also indicated

for the replacement of small- to moderate-sized

failed restorations. When the faciolingual extension

of the occlusal aspect of a given defect exceeds

2/3 of the distance between a primary mesiodistal

groove and the tip of the cusp, composite use is

compromised (

Figure 1

). The same is true for

proximal defects/preparations with gingival margins

extending where no enamel is available for bonding.

Moisture control is necessary for the appropriate

placement of posterior composites, and is usually

accomplished with rubber dam isolation. However,

selective conservative composite restorations can

be placed in compliant patients with alternative

isolation methods, when the rubber dam cannot

be used.

Esthetics is a commonly mentioned indication

for composite use in posterior teeth, but it is only

justifiable when the above-discussed limitations

are carefully considered and respected. The

American Dental Association accurately describes

the indications and contraindications for the use of

resin-based composites in posterior teeth:

Indications

•

Pit-and-fissure sealants (“filled sealants”)

•

Preventive (conservative) resin restorations

•

Classes I (occlusal) and II (occlusoproximal)

restorations for both initial and moderate size

lesions, using modified conservative tooth

preparations (See

Figure 2

)

•

Class V restorations

•

Esthetically important areas

•

Patients allergic or sensitive to metals

In addition, teeth presenting fracture lines can

also be considered an indication for the use

of posterior composites. By restoring such teeth

using an adhesive technique and composites, the

propagation of the fracture line might be halted.

Contraindications

•

Patients with heavy occlusal stress

•

Sites that cannot be properly isolated

•

Patients who are allergic or sensitive to resin-

based composite materials

Heavy occlusal stresses can be present when

the patient indicates parafunctional activities such

as bruxing and/or clenching. More objectively,

heavy occlusal stresses can be identified when the

patient presents with multiple fractured posterior

teeth, flagrant wear facets in several posterior and

anterior teeth, and visibly worn occlusal and incisal

surfaces. For these patients, posterior defects are

Figure 1

(A)

Diagrammatic representation of a posterior segment with the outline of ideal posterior composite

restorations. Note that the isthmus widths do not exceed 2/3 of the distance between the facial and

lingual cusp tips. When proximal caries does not extend into the occlusal surface, box preparations

can be used such as the ones illustrated in the second bicuspid.

(B)

Diagrammatic representation of a posterior segment with the outline of acceptable posterior

composite restorations. Note that the isthmus widths do not exceed 2/3 of the distance between facial

and lingual cusp tips.

(C)

Diagrammatic representation of a bicuspid with the outline of a mesioocclusodistal (MOD) poste-

rior composite restoration. Note that the occlusal isthmus width does not exceed 2/3 of the distance

between the facial and lingual cusp tips. The red shaded area represents the facial and lingual

extensions of the respective axial walls. These extensions have to be considered when evaluating the

appropriateness of composite restorations (compare with Figure 1D).

(D)

Diagrammatic representation of a bicuspid with the outline of a MOD posterior composite restora-

tion. Note that the occlusal isthmus width does not exceed 2/3 of the distance between facial and

lingual cusp tips. However, the red shaded area representing the facial and lingual extensions of the

respective axial walls extends considerably towards the facial and lingual surfaces. Note also that in

this example the faciolingual extension of the gingival walls undermine the cusps, which can lead to

potential cusp fracture. These extensions would be inappropriate for a posterior composite restoration.