Marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation of four finish line locations

Abstract

This study evaluated the marginal and internal fit and intaglio surface trueness of interim crowns fabricated from tooth preparation scanned at four finish line locations. The right maxillary first molar tooth preparation model was fabricated using a ceramic material and placed in four finish line locations (supragingival, equigingival, subgingival, and subgingival with a cord). Intraoral scanning was performed. Crowns were designed based on the scanned area. Interim crowns were fabricated using a stereolithography three-dimensional (3D) printer (N = 16 per location). Marginal and internal fit were evaluated with a silicone replica technique. Intaglio surface trueness was evaluated using a 3D inspection software. One-way analysis of variance and Tukey HSD test were performed for comparisons (α = 0.05). The marginal and internal fit showed significant differences according to locations (P < 0.05); the marginal fit showed the best results in the supragingival finish line (P < 0.05). Intaglio surface trueness was significantly different in the marginal region, with the highest value in the subgingival location (P < 0.05). Crowns fabricated on the subgingival finish line caused inaccurate marginal fit due to poor fabrication reproducibility of the marginal region. The use of an intraoral scanner should be decided on the clinical situation and needs.

Trueness of 3D printed partial denture frameworks: build orientations and support structure density parameters

“…Research has been conducted to study the influence of all these parameters on the accuracy of the crowns, casts, complete denture bases and implant digital surgical guides. 13 15 16 17 18 19 20 21 …”

“…6 11 Many articles applied the reverse engineering and metrology 3D analysis software to precisely detect the quantitative and qualitative 3D deviations between the reference 3D objects and the scanned objects. 19 20 21 Generally, quantitative analysis was represented as root-mean-square estimate and the qualitative analysis was done by studying and interpreting the color maps generated in the software report representing the surface positive and negative 3D deviations. 13 16 19 20 …”

“… 19 20 21 Generally, quantitative analysis was represented as root-mean-square estimate and the qualitative analysis was done by studying and interpreting the color maps generated in the software report representing the surface positive and negative 3D deviations. 13 16 19 20 …”

Optimization of Digital Light Processing Three-Dimensional Printing of the Removable Partial Denture Frameworks; The Role of Build Angle and Support Structure Diameter

“…Another technique was applied by checking the fitness of the protheses on the underlying cast by matching between their surfaces and digitally measuring gap distance between reference points [ 3 , 6 , 24 ]. Studies also measured the internal fit through micro-computed tomography (µ CT) between the tested surfaces, followed by correlation to the trueness values [ 21 , 22 , 25 ]. Other less accurate examinations were considered such as the visual observation, clinical assessment, and checking the internal fit by silicone registration material [ 26 ].…”

How Does the Use of an Intraoral Scanner Affect Muscle Fatigue? A Preliminary In Vivo Study

“…Recently, as the application of dental computer-aided design and computer-aided manufacturing (CAD/CAM) has rapidly increased. The use of intraoral scanners has also increased [ 16 ]. Although manufacturers have reduced the weight and size of intraoral scanners for usability, these scanners are still one of the heaviest medical devices used directly in the oral cavity [ 17 ].…”