Analysis of Posterior Zirconia Crowns with Vertical Margin Preparations

BACKGROUND: The interest in vertical crown preparation is growing and several variations are presented in the dental literature but limited clinical outcome data exists for teeth prepared for a vertical finish line. AIM: To audit clinical outcomes for 73 teeth after vertical preparation for knife-edge zirconia crowns. METHOD: Seventy-three teeth had knife-edge zirconia crowns placed after vertical finish line preparation. The outcomes for these teeth were analysed from a retrospective audit of clinical records. RESULTS: The mean follow-up time was 21 months (SD: 10 months; range: 6-40). One tooth had to be extracted due to fracture at cervical level. One crown had to be re-made after margin fracture during try-in. No subsequent endodontic treatment was needed for any of the prepared teeth. No change in alveolar bone height was noted on radiographic follow-up. The mean bleeding score for the crowned teeth was higher than the mean bleeding score for a control tooth, but this was not statistically significant. CONCLUSION: This retrospective evaluation has shown favourable outcomes for 72 teeth after vertical preparation for knife-edge crowns. Longer follow-up is needed but the present results show that the technique is a viable procedure with potential advantages.