Evaluation of the effect of abutment preparation angles on the repeatability and reproducibility using a blue light model scanner

PURPOSE. The purpose of the study is to evaluate the repeatability and reproducibility of the abutment angle using a blue light scanner. MATERIALS AND METHODS. 0°, 6°, and 10° wax cast abutment dies were fabricated. Each of the silicone impression was produced using the replicable silicone. Each study die was constructed from the prepared replicable stone used for scans. 3-dimensional data was obtained after scanning the prepared study dies for the repeatability by using the blue light scanner. The prepared 3-dimensional data could have the best fit alignment using 3-dimensional software. For reproducibility, each abutment was used as the first reference study die, and then it was scanned five times per each. 3-dimensional software was used to perform the best fit alignment. The data obtained were analyzed using a nonparametric Kruskal-Wallis H test (α=.05), post hoc Mann-Whitney U test, and Bonferroni correction (α=.017). RESULTS. The repeatability of 0°, 6°, and 10° abutments was 3.9, 4.4 and 4.7 ㎛, respectively. Among them, the 0° abutment had the best value while the 10° abutment showed the worst value. There was a statistically significant difference (P<.05). The reproducibility of 0°, 6°, and 10° abutments was 6.1, 5.5, and 5.3 ㎛, respectively. While the 10° abutment showed the best value, the 0° abutment showed the worst value. However, there was no statistically significant difference (P>.05). CONCLUSION. In repeatability, the 0° abutment showed a positive result. In reproducibility, the 10° abutment achieved a positive result.