Open proximal contact in Class II composite
What it is
After a Class II composite restoration, the proximal contact is weak or absent — floss passes with little or no resistance and patients often report food impaction. Clinically, open or weak contacts are linked to plaque retention, gingival inflammation, periodontal issues, and recurrent caries risk around the restoration.
Why it happens
• Wrong matrix system choice: circumferential matrices (e.g., Tofflemire) are more likely to produce flatter contours and weaker contacts compared with sectional matrices with separation rings. • No tooth separation during curing: without a separation ring (or equivalent), you may not compensate for matrix thickness and polymerization effects → contact ends up open. • Incorrect wedge selection/placement (too small, wrong embrasure, wedge not seated) → matrix not adapted at gingival margin and contact area not pushed correctly toward the adjacent tooth. • Matrix not burnished/contoured at the contact area (or distorted ring placement) → contact point forms too broad/too flat or ends up short of the adjacent tooth.
The full clinical mistake entry includes
- How to avoid it — the prevention protocol
- The clinical tip experienced clinicians use
- The documented reference behind the mistake
More clinical mistakes
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