Understanding and resolving 'washed or tissue over margins' in digital impressions is crucial for the accuracy of crown and bridge restorations. This article guides you through preventing and detecting this common issue.
What is a 'Washed' Margin?
Washed margins occur when tissue, blood, saliva, or other substances obscure the tooth's margin in a digital scan, complicating accurate margin identification.
Using the below prevention strategies can significantly improve the margin quality of scans.
Retraction Techniques: Employ one or two cords and hemostatic agents for clearer margins.
- Note: Read our Recommended Crown and Bridge Retraction Techniques article to learn more about retraction techniques.
- Assistant Support: A dental assistant can manage saliva and provide additional scanning perspectives.
Tips For Improved Scans
- Subgingival Margin Scanning: Position the mirror tip close to the margin to capture accurate margins.
- Mandibular Adjustment: Guide the patient to shift their jaw for better posterior area imaging.
- HD Scans Feature: Use this tool in Chairside for detailed margin analysis.
- CAD/CAM Spray: Helps in detecting gold crowns.
Examples of Good Quality Scans
There is a clear distinction between where the tooth ends and where the margin begins. It all looks like one smooth surface.
Examples of Poor Quality Scans
When tissue covers the margin, it masks the distinction between the tooth and surrounding soft tissue. This will require digital adjustment and designer margin estimation.
Live Scan Review Assistance
Review our Contact Us article to learn how our Live Scan Review team is available to offer real-time guidance for optimal scanning results.