Qualitative Analysis of the Cementation Line of Metal-Ceramic Crowns Luted With Resin Cement: A Clinical Case Report

Unlike conventional water-soluble luting cements, which gradually dissolve in oral fluids and partially self-correct over time, polymerized resin cement is insoluble and will not be displaced from the restoration margin without active mechanical intervention. This case report describes the qualitative analysis of the cementation line of three metal-ceramic crowns 1 year after placement using scanning electron microscopy (SEM) and the replica technique, and the subsequent clinical management. A 45-year-old female patient presented with crowns on Teeth 11, 21, and 22 cemented with a self-adhesive dual-cure resin cement (RelyX U200, 3 M ESPE). Despite presenting with clinical signs of localized gingivitis, the patient reported no pain or discomfort and was entirely unaware of the presence of residual cement. SEM analysis revealed cement excess of 200-500+ μm, 10-23 times the manufacturer-specified film thickness of 22 μm, in cervical, interproximal, and subgingival regions. Following mechanical cement removal, resolution of bleeding on probing and reduction in probing depths were observed at all affected sites, providing direct clinical evidence of a causal relationship between residual resin cement and local gingival inflammation. These findings highlight the limitations of symptom-based monitoring and underscore that postcementation polishing is a definitive clinical requirement, not a discretionary step.