Shinyoung An1, Sungtae Kim2, Hyunmin Choi3, Jae-Hoon Lee4, Hong-Seok Moon5. 1. Clinical Assistant Professor, Advanced Education in General Dentistry, Yonsei University College of Dentistry, Seoul, Korea. 2. Assistant Professor, Department of Periodontology, Dental Research Institute, Seoul National University School of Dentistry, Seoul, Korea. 3. Graduate student, Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Korea. 4. Associate Professor, Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Korea. 5. Professor, Department of Prosthodontics, Yonsei University College of Dentistry, Seoul, Korea. Electronic address: hsm5@yuhs.ac.
Abstract
STATEMENT OF PROBLEM: Digital impression systems have been developed to overcome the disadvantages associated with conventional impression methods. PURPOSE: The purpose of this study was to compare the marginal fit of zirconia copings designed with the use of an iTero digital scanner with those designed by the conventional impression technique. MATERIAL AND METHODS: Thirty identical cast, base-metal dies from 1 maxillary central incisor prepared for a ceramic crown restoration were fabricated. For the conventional impression group (CI), base metal dies (n=10) were replicated as stone dies by means of a conventional impression technique with polyvinyl siloxane material. For the iTero with polyurethane group (iP), base metal dies (n=10) were replicated as polyurethane dies with the iTero digital impression system. For the iTero with no dies group (iNo), base metal dies (n=10) were scanned with the iTero digital impression system, but no dies were fabricated. For each group, 10 zirconia copings were fabricated based on the stone dies (CI group), polyurethane dies (iP group), or stereolithography files (iNo group). The marginal gap of each specimen was measured with a light microscope at ×50 magnification. One-way analysis of variance and the Tukey honestly significant difference test were used for statistical analysis (α=.05). RESULTS: Statistically significant differences were found between the CI group and iP group (P<.05) and between the CI group and iNo group (P<.05). CONCLUSIONS: The marginal gap between the restoration and definitive cast base metal die was greater in the groups that used the digital impression method than in the group that used the conventional impression method. However, the marginal discrepancies of all of the groups were clinically acceptable.
STATEMENT OF PROBLEM: Digital impression systems have been developed to overcome the disadvantages associated with conventional impression methods. PURPOSE: The purpose of this study was to compare the marginal fit of zirconia copings designed with the use of an iTero digital scanner with those designed by the conventional impression technique. MATERIAL AND METHODS: Thirty identical cast, base-metal dies from 1 maxillary central incisor prepared for a ceramic crown restoration were fabricated. For the conventional impression group (CI), base metal dies (n=10) were replicated as stone dies by means of a conventional impression technique with polyvinyl siloxane material. For the iTero with polyurethane group (iP), base metal dies (n=10) were replicated as polyurethane dies with the iTero digital impression system. For the iTero with no dies group (iNo), base metal dies (n=10) were scanned with the iTero digital impression system, but no dies were fabricated. For each group, 10 zirconia copings were fabricated based on the stone dies (CI group), polyurethane dies (iP group), or stereolithography files (iNo group). The marginal gap of each specimen was measured with a light microscope at ×50 magnification. One-way analysis of variance and the Tukey honestly significant difference test were used for statistical analysis (α=.05). RESULTS: Statistically significant differences were found between the CI group and iP group (P<.05) and between the CI group and iNo group (P<.05). CONCLUSIONS: The marginal gap between the restoration and definitive cast base metal die was greater in the groups that used the digital impression method than in the group that used the conventional impression method. However, the marginal discrepancies of all of the groups were clinically acceptable.
Authors: Michael S McCracken; David R Louis; Mark S Litaker; Helena M Minyé; Thomas Oates; Valeria V Gordan; Don G Marshall; Cyril Meyerowitz; Gregg H Gilbert Journal: J Prosthodont Date: 2017-01-11 Impact factor: 2.752