HOW TO AVOID SECONDARY CARIES IN PROXIMAL COMPOSITE RESTORATIONS
Secondary caries in proximal restorations is one of the common reasons for failure of proximal composite restorations.
Development of secondary caries in proximal restorations is mainly due to improper marginal adaptation of the restoration at the gingival margin. This occurs more frequently in the light cure resin composite restorations than any other restorative material because of difficulty in achieving close rigid contact of transparent matrix band to the gingival margin. This has paved way to use of metal matrix band for composite restorations. The disadvantage with this technique is the inability to light cure the gingival proximal margins, leading to post operative sensitivity and initiation of carious process. The use of contact wedges for such cases will give rewarding restorations with perfect marginal adaptation, contact and contour.
Contact wedges are easy to use elastic wedges available in three sizes for small, medium and large gingival embrasure areas.They can be easily inserted in between the teeth with the device supplied by the manufactures or by the orthodontic separating pliers. They can be used along with both transparent and metal matrix band. Even though contact ring as matrix retainer is advised to use along with these wedges, in most instances correct selection of these wedges will achieve excellent contact and contour even without retainer. These wedges along with transparent matrix band have perfect symbiotic relationship for resin composite restoration.
This image shows the contact wedge with transparent band for the proximal restoration in mandibular premolar. Since the light can penetrate through the transparent band, first layer of composite material is placed over the gingival seat and light cured, before further increments for horizontal incremental technique. The large cavities of molars can be restored by oblique incremental technique.
The final completed restoration shows good, esthetics, contact and contour.
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