Effect of pulp chamber depth on failure load and mode of failure of CAD/CAM endocrowns

Aim: The present study aimed to investigate the effect of pulp chamber depth on the failure load and mode of failure of CAD/CAM endocrowns.
Materials and methods: Thirty mandibular molars were sectioned above the cementoenamel junction (CEJ), followed by root canal treatment. Teeth were sectioned at a level of 1.5 mm above the CEJ, arranged from the lowest to the highest depths, and divided into three groups (n = 10): group SE: Shallow pulp chamber (1.42 to 2.17 mm); group IE: Intermediate pulp chamber (2.25 to 3.17 mm); group DE: Deep pulp chamber (3.33 to 5.17 mm). CAD/CAM endocrowns were fabricated by milling lithium disilicate ceramic blocks and were cemented using resin cement. Teeth were embedded in acrylic resin at 2 mm below the CEJ, and a compressive load was applied to create a 45-degree angled functional loading simulation until the occurrence of failure.
Results: The mean failure loads were highest in group DE (1893.75 ± 496.08 N) compared with groups IE (1103.71 ± 254.59 N) and SE (1084.63 ± 240.92 N), with statistically significant differences between group DE and both groups IE and SE (P < 0.001). Pearson correlation coefficient (PCC) revealed a strong positive correlation between the pulp chamber depth and failure load of the endocrowns. The failure mode for all samples was catastrophic failure.
Conclusion: The pulp chamber depth affected the failure load of the teeth restored with endocrowns. The failure loads were higher in teeth with a greater pulp chamber depth. (Int J Comput Dent 2023;26(1): 31–0; doi: 10.3290/j.ijcd.b3818295)