Ryan M Mizumoto1, Burak Yilmaz2, Edwin A McGlumphy3, Jeremy Seidt4, William M Johnston5. 1. Graduate student, Advanced Prosthodontics Residency Program, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio. Electronic address: mizumoto.1@osu.edu. 2. Associate Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio. 3. Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio. 4. Adjunct Assistant Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio; and Research Scientist, Department of Mechanical & Aerospace Engineering, The Ohio State University College of Engineering, Columbus, Ohio. 5. Emeritus Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio.
Abstract
STATEMENT OF PROBLEM: The effect of various scan bodies and scanning techniques on the accuracy and scan time for completely edentulous patients is not well understood. PURPOSE: The purpose of this in vitro study was to evaluate the effects of 4 scanning techniques and 5 intraoral scan bodies (ISBs) on the trueness, precision, and scan time in a completely edentulous arch with 4 implants. MATERIAL AND METHODS: Five different ISB systems: AF, NT, DE, C3D, and ZI, and 4 different scanning techniques: unmodified master model (NO), glass fiduciary markers placed on the edentulous ridge (GB), pressure-indicating paste brushed over the ridge and palate (PP), and floss tied between the scan bodies (FL), were evaluated. Scan bodies were attached to an edentulous maxillary model with 4 dental implant analogs and scanned by using a structured blue light industrial scanner, and 5 consecutive digital scans of the model were made by using an intraoral scanner and 1 of the 4 techniques (n=5). The scans were superimposed on the master reference model, and the distance deviation and angular deviation of the scan bodies was calculated. The scan time was also recorded. A 2-factor ANOVA was used to examine the effect of scan body and technique on the trueness and scan time, with subsequent Tukey honestly significant difference or Bonferroni-corrected Student t tests. Precision was evaluated by tests for homogeneity of the variances between groups. Reliability for the entire study was evaluated using the intraclass correlation coefficient (α=.05 for all tests). RESULTS: The overall reliability of the study according to intraclass correlations was 0.999. In terms of trueness, no statistically significant interaction was found between the effects of scan body and technique on the distance deviation (P=.246); however, the scan body (P=.031) and technique (P<.001) each had a significant effect independently. A statistically significant interaction was found between the effects of the scan body and technique on angular deviation (P<.001). Testing for the homogeneity of variances demonstrated significant differences in the precision among the groups in terms of distance deviation (P≤.013) and angular deviation (P≤.003). No statistically significant interaction was found between the effects of the scan body and technique (P=.076) on the scan time; however, the scan body alone was found to have a significant effect (P<.001). CONCLUSIONS: The accuracy (trueness and precision) of complete-arch digital implant scans using ISBs was affected by both the scan body and scan technique when using an intraoral scanning system. The ZI scan body had significantly less distance deviation, whereas splinting scan bodies with floss led to significantly more distance deviation. The scan techniques with different surface modifications were not found to improve the scan accuracy. The use of different ISBs led to significant differences in the scan time.
STATEMENT OF PROBLEM: The effect of various scan bodies and scanning techniques on the accuracy and scan time for completely edentulous patients is not well understood. PURPOSE: The purpose of this in vitro study was to evaluate the effects of 4 scanning techniques and 5 intraoral scan bodies (ISBs) on the trueness, precision, and scan time in a completely edentulous arch with 4 implants. MATERIAL AND METHODS: Five different ISB systems: AF, NT, DE, C3D, and ZI, and 4 different scanning techniques: unmodified master model (NO), glass fiduciary markers placed on the edentulous ridge (GB), pressure-indicating paste brushed over the ridge and palate (PP), and floss tied between the scan bodies (FL), were evaluated. Scan bodies were attached to an edentulous maxillary model with 4 dental implant analogs and scanned by using a structured blue light industrial scanner, and 5 consecutive digital scans of the model were made by using an intraoral scanner and 1 of the 4 techniques (n=5). The scans were superimposed on the master reference model, and the distance deviation and angular deviation of the scan bodies was calculated. The scan time was also recorded. A 2-factor ANOVA was used to examine the effect of scan body and technique on the trueness and scan time, with subsequent Tukey honestly significant difference or Bonferroni-corrected Student t tests. Precision was evaluated by tests for homogeneity of the variances between groups. Reliability for the entire study was evaluated using the intraclass correlation coefficient (α=.05 for all tests). RESULTS: The overall reliability of the study according to intraclass correlations was 0.999. In terms of trueness, no statistically significant interaction was found between the effects of scan body and technique on the distance deviation (P=.246); however, the scan body (P=.031) and technique (P<.001) each had a significant effect independently. A statistically significant interaction was found between the effects of the scan body and technique on angular deviation (P<.001). Testing for the homogeneity of variances demonstrated significant differences in the precision among the groups in terms of distance deviation (P≤.013) and angular deviation (P≤.003). No statistically significant interaction was found between the effects of the scan body and technique (P=.076) on the scan time; however, the scan body alone was found to have a significant effect (P<.001). CONCLUSIONS: The accuracy (trueness and precision) of complete-arch digital implant scans using ISBs was affected by both the scan body and scan technique when using an intraoral scanning system. The ZI scan body had significantly less distance deviation, whereas splinting scan bodies with floss led to significantly more distance deviation. The scan techniques with different surface modifications were not found to improve the scan accuracy. The use of different ISBs led to significant differences in the scan time.
Authors: Simone Marques; Paulo Ribeiro; Carlos Falcão; Bernardo Ferreira Lemos; Blanca Ríos-Carrasco; José Vicente Ríos-Santos; Mariano Herrero-Climent Journal: Int J Environ Res Public Health Date: 2021-01-24 Impact factor: 3.390