Microcomputed tomography evaluation of cement film thickness of veneers and crowns made with conventional and 3D printed provisional materials

Abstract

Objective To evaluate, through microcomputed tomography (μCT), the cement film thickness of veneers and crowns made with different provisional materials. Material and Methods A veneer and a crown preparation were performed on a central incisor and a second molar of a dental model, respectively, scanned with an intraoral scanner, and the .stl files were exported to an LCD‐based SLA three‐dimensional (3D)‐Printer. Twenty‐four preparations were 3D‐printed for each veneer and crown and divided into four groups (n = 6/group): (a) Acrylic resin (Acrílico Marche); (b) Bisacrylic resin (Protemp 4); (c) PMMA computer‐aided design and computer‐aided manufacturing (CAD‐CAM) (Vipiblock); and (d) 3D‐printed resin for provisional restorations (Raydent C&B for temporary crown and bridge). Veneers and crowns restorations were performed and cemented with a flowable composite. Each specimen was scanned with a μCT apparatus, files were imported for data analysis, and cement film thickness was quantitatively measured. Data were analyzed by 2‐way ANOVA and Tukey post‐hoc tests (α = .05). Results Crowns presented a thicker cementation film than veneers (P < .05).The bisacrylic resin showed the smallest veneer film thickness, similar to the acrylic resin (P = .151), which was not significantly different than the PMMA CAD/CAM material (P = .153). The 3D printed provisional material showed the thicker film, different than all other materials (P < .05). The bisacrylic resin showed a cement film thickness with a high number of voids in its surface. For crowns cementation, the 3D printed provisional material showed the thicker cementation film, different than all other materials (P < .05). Conclusions Different provisional materials present different film thicknesses. The 3D printed provisional material showed the highest veneer and crown film thicknesses. Veneers film thicknesses were smaller than crowns for all provisional materials. Clinical Significance The 3D printed provisional material studied can be satisfactorily used, presenting appropriate adaptation with the tooth preparation, however, it shows the highest cement film thickness for both veneers and crowns cementations when compared with other provisional materials. A better internal fit, or smaller cement film thickness is obtained by CAD/CAM materials, acrylic and bisacrylic resins. Veneer cementation showed a smaller cement film thickness compared with crown cementation for all provisional materials.

Comparative Analysis of Fracture Resistance between CAD/CAM Materials for Interim Fixed Prosthesis

“…The authors suggested and attributed this result to the shrinkage that the material undergoes during construction and post-production. In turn, they attributed this to the manipulation of data in the STL file, where conversion and formatting were generated and could result in changes [38][39][40][41].…”

A Review of 3D Printing in Dentistry: Technologies, Affecting Factors, and Applications

“…It is undisputed that 3D printing has a great potential for prosthetics, as doctors can prepare, scan, and print their teeth in a session in clinically relevant situations, saving time and money [78]. Using intraoral or extraoral scanners, precise virtual models of the teeth can be prepared.…”

“…A good fit is essential to guarantee the mechanical stability, durability, and health of surrounding soft tissues [78]. Insufficient adaptability can lead to dental plaque accumulation, microleaking of adhesive, discoloration of edges, and [12] Low costs [11] Complete dentures Convenient and fast [13] Accurate [14] Close adaptability [10] Removable partial denture frameworks Uniform contact pressure [15] Good mechanical properties [16] Oral and maxillofacial surgery Occlusal splints Saving time and cost [17] Surgical implants High mechanical strength [18] Adjustable porosity [19] Prostheses Convenient and fast [20] Accurate [21] Working models Improving the integrity and aesthetics [22] Reducing operative time and risk [23] Oral implantology…”

Application of 3D printing and its various technologies in dentistry

“…Accordingly, these technologies can effectively save time and cost. 10 In addition, clinicians can effectively prepare optimal teeth models by using extraoral or intraoral scanners. CAD software can be used to achieve favorable restorations and treatment outcomes.…”

“…A good fit is recommended when planning for the treatment strategy to maintain the surrounding tissues' health, durability, and mechanical stability. 10 If the materials were not adequately fit, various adverse events could develop in this context. These include the development of periodontal diseases, dental caries, tooth sensitivity, lack of esthetics, discoloration, microleakage of adhesive, and dental plaque accumulation over the edges.…”