Dataset Information

Randomized Clinical Trial comparing clinical adjustment times of CAD/CAM screw-retained posterior crowns on ti-base abutments created with digital or conventional impressions. One-year follow-up.

ABSTRACT:

Objectives

The purpose of this randomized clinical trial was to compare the required time of potential clinical adjustments of posterior screw-retained monolithic zirconia implant retained crowns based on intraoral optical scanning (IOS) or conventional impressions.

Materials and methods

Patients with posterior tissue level implants (Straumann RN) replacing solitary teeth were recruited. Of all patients, impressions were taken with both an IOS (3M^™ TDS) and a conventional (polyether) pick-up impression. Randomization was performed after impression taking and patients were to receive either a crown based on the digital or the conventional impression. The time required for adjustments at placement was recorded. Additionally, restoration survival and mechanical complications with a follow-up of one year were documented.

Results

Thirty two patients with 45 implants were included: 23 restorations in the test (IOS) and 22 in the control (conventional) group. The average adjustment time was 3.35 min (SD ± 3.38, range: 0-11 min) for the digital versus 6.09 min (SD ± 4.63, range: 0-18 min) for the conventional impressions (p = .039). A proper fit (no adjustments required) was achieved 39,1% in the digital and 18,2% conventional group respectively. All 45 restorations could be placed within the two planned appointments and only two minor mechanical complications occurred during the first year of function.

Conclusions

The use of IOS resulted in shorter adjustment times at try-in than conventional impressions for solitary CAD/CAM implant restorations. Screw-retained solitary monolithic zirconia restorations on ti-base abutments show low complication- and survival rates in the short term.

SUBMITTER: Derksen W

PROVIDER: S-EPMC8453558 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The advancement of intraoral scanners has allowed for more efficient workflow in the dental clinical setting. However, limited data exist regarding the accuracy of the digital impressions produced with various scanner settings and scanning approaches. The purpose of this in vitro study was to compare the accuracy of digital impressions at the crown preparation margin using different scanning resolutions of a specific intraoral scanner system. An all-ceramic crown preparation of a mandibular first molar was constructed in a typodont, and a scan (n = 3) was created with an industrial-grade laboratory scanner (3Shape D2000) as the control. Digital impressions were obtained with an intraoral scanner (3Shape TRIOS 3) under three settings-high resolution (HR), standard resolution (SR), and combined resolution (SHR). Comparative 3D analysis of scans was performed with Geomagic Control X software to measure the discrepancy between intraoral scans and the control scan along the preparation finish line. The scan time and number of images captured per scan were recorded. Statistical analysis was performed by one-way ANOVA, two-way repeated measures ANOVA, Pearson's correlation, and Dunnett's T3 test (? = 0.05). Significant differences were observed for scan time and for number of images captured among scan resolution settings (? < 0.05). The scan time for the SR group was, on average, 34.2 s less than the SHR group and 46.5 s less than the HR group. For discrepancy on the finish line, no significant differences were observed among scanning resolutions (HR: 31.5 ± 5.5 ?m, SHR: 33.2 ± 3.7 ?m, SR: 33.6 ± 3.1 ?m). Significant differences in discrepancy were observed among tooth surfaces, with the distal surface showing the highest discrepancies. In conclusion, the resolution of the intra-oral scanner is primarily defined by the system hardware and optimized for default scans. A software high-resolution mode that obtains more data over a longer time may not necessarily benefit the scan accuracy, while the tooth preparation and surface parameters do affect the accuracy.