Automatic Digital Design of the Occlusal Anatomy of Monolithic Zirconia Crowns Compared to Dental Technicians’ Digital Waxing: A Controlled Clinical Trial

Abstract

Purpose Reconstructing the occlusal morphology of posterior teeth in definitive dental prosthesis can be challenging. The use of the correlation technique enables replication of the information and occlusal anatomy of interim dental prostheses to the definitive ones. The purpose of this controlled clinical trial was to compare the static and dynamic contacts (SDC) of monolithic zirconia crowns designed with correlation and library techniques. Material and Methods Twenty‐four patients were included in the study for a total of 28 molars. For each abutment tooth, an interim crown was fabricated and two digital scans, with and without the interim crown in place were made. Two single crowns were designed using correlation and library techniques. Fifty‐six monolithic zirconia crowns were milled. The interim and definitive crowns were evaluated intraorally for SDC by using a 24‐μm‐thick blue articulating foil. After removing the interim and definite crowns, extraoral photographs were taken to calculate the SDC area using software (ImageJ) and analyzed by the Kruskal‐Wallis test. Results The average and ± standard deviation (SD) of area of the occlusal marks on interim crowns was 32.27 ± 3.45 mm2. Definitive crowns designed by using the correlation technique had an area of 31.01 ± 3.73 mm2; the area in the library technique was 36.85 ± 5.78 mm2. No statistically significant difference was found (p = 0.091) between the occlusal mark areas of the interim and definitive crowns designed by using the correlation technique. Whereas, there were significant differences between the areas of occlusal marks of the interim and definitive crowns designed by using the library technique, and between the areas of occlusal marks of definitive crowns designed by using the correlation and library techniques (p < 0.001). Conclusion The average area of the SDC of monolithic zirconia crowns designed by using the correlation technique was similar to that of interim crowns. The library technique was less effective when replicating the SDC compared to the correlation technique.

Assessment of Fit on Ten Screw-Retained FrameworksRealized through Digital Full-Arch Implant Impression

“…During scanning, a dry field was maintained using a dental aspirator. The implant-supported temporary prosthesis was acquired to transfer the vertical dimension, shape, and occlusal morphology to the definitive prosthesis [5]. The 10 STL files were uploaded to CAD software (Exocad, Exocad DentaCad, Darmstadt, Germany) to design the frameworks.…”

“…A decrease in operative time and patient discomfort and increased accuracy represent the main advantages that digital technology has introduced into clinical practice [2,3]. Regarding the digital impression for single crowns [4,5] or three-unit fixed dental prostheses (FDPs) [6], several authors have demonstrated the better performance of a digital workflow. However, discordant opinions have emerged among clinicians and researchers regarding a digital impression for full-arch implant-supported FDPs.…”

Accuracy of tooth‐implant impressions: Comparison of five different techniques

“…Precise impression making from dental implants is one of the influential factors in achieving passive fit (Alikhasi et al, 2015 ). Inaccurate impressions or prosthetic fabrication can lead to incomplete seating of restoration, which results in insufficient adhesion, microleakage, tooth hypersensitivity, dental caries, need for endodontic treatment, and gingival inflammation (Di Fiore et al, 2019 ; Fathi, Hashemi et al, 2023 ) and inflict delayed pain and discomfort on the patient (Shadmehr et al, 2021 ). Utilizing digital tools has been lucrative in various fields of dentistry including radiology and prosthodontics.…”

Comparison between Occlusal Errors of Single Posterior Crowns Adjusted Using Patient Specific Motion or Conventional Methods

“…The design of a single crown restoration should be in a functionally and anatomically harmonic relationship with the adjacent and antagonistic teeth [1][2][3][4][5]. The occlusal surface of a single crown should offer functional stability in maximum intercuspation (MICP) and no interference during eccentric movements [6].…”