Impact of Marginal Elevation in Restored Endodontically Treated Teeth with CAD/CAM Ceramic Endocrowns on the Marginal Adaptation (In Vitro)

Abstract

Aim: To assess the effect of marginal elevation in endodontically treated teeth repaired with CAD/CAM ceramic endocrowns on marginal adaptation. Materials and methods: 20 sound mandibular first molars were treated endodontically and prepared for endocrowns with a butt-joint occlusal edge and mesial proximal box. They were divided into two groups (n = 10 each) based on ceramic type: Group H (hybrid ceramic) and group L [lithium disilicate ceramics (LDS) ceramic]. Each group was further divided into subgroups E (with marginal elevation) and N (without marginal elevation), with 5 specimens each. The endocrowns were cemented using dual-cured self-adhesive resin cement and exposed to 5000 thermal aging cycles (5–55°C). Marginal adaptation was evaluated using a stereo microscope at five mesial margin locations, and the mean gap measurement was calculated. Results: The lowest marginal gap measurements were recorded by hybrid ceramic (Grandio) with deep marginal elevation (23.25 μm), which is significantly lower than all tested subgroups (p < 0.001). The highest marginal gap measurement was recorded by LDS (IPS e.max) CAD without deep marginal elevation (57.62 μm), which is significantly higher than all tested sub-groups. Conclusion: Compared to LDS IPS e.max, hybrid ceramics with and without marginal elevation exhibit superior marginal adaptation. Clinical significance: Marginal adaptation of endocrowns is critical for proper seal, preventing micro leakage and secondary caries, thus enhancing restoration longevity and patient outcomes for severely damaged teeth.