Three-dimensional printing of occlusal devices for temporomandibular disorders by using a free CAD software program: A technical report

Mechanical Properties of 3D-Printed Occlusal Splint Materials

Data regarding the mechanical properties of three-dimensionally (3D) printed materials for occlusal splint manufacturing are scarce. The aim of the present study was to evaluate the flexural strength and surface hardness of modern 3D-printed occlusal splint materials and compare them with two control groups, namely, milled and conventional cold-polymerized occlusal splint materials. A total of 140 rectangular specimens were manufactured for the present study. The specimens were prepared in accordance with the International Organization for Standardization standards (ISO 20795-1:2013). Five 3D-printed (NextDent Ortho Rigid, Dental LT Clear, Dentona Flexisplint, Cosmos Bite Splint, and ProArt Print Splint), one milled (ProArt CAD Splint), and one cold-polymerized (ProBase Cold) occlusal splint materials were used to determine flexural strength and surface hardness values. The three-point flexure test was used for the determination of flexural strength values, while Vickers hardness was measured to determine surface hardness. Ten specimens (n = 10) of each material were tested using these procedures. One-way ANOVA and Tukey's post-hoc test were used to analyze the obtained results (α = 0.05). The values of flexural strength ranged from 46.1 ± 8.2 MPa to 106 ± 8.3 MPa. The Vickers hardness values ranged from 4.9 ± 0.5 VHN to 20.6 ± 1.3 VHN. Significant differences were found among the tested materials (p < 0.0001). The milled and cold-polymerized materials yielded higher values for both flexural strength (only one 3D-printed resin had comparable results to cold-polymerized acrylics) and surface hardness. There are differences in the mechanical properties of the various tested occlusal splint materials. The flexural strength of most of the 3D-printed materials and their surface hardness values are still inferior when compared to the milled or cold-polymerized materials.

Utilization of a 3D Printed Orthodontic Distalizer for Tooth-Borne Hybrid Treatment in Class II Unilateral Malocclusions

This paper introduces a novel method of 3D designing and 3D printing of a hybrid orthodontic tooth-borne personalized distalizer for treatment of unilateral Class II malocclusion. Research objectives were to clinically utilize 3D printed distalizers, appraise feasibility of this technique and compare two different biocompatible photopolymers (white and transparent). Frequency of distalizers’ debonding and patients’ aesthetical perception was evaluated on the set of 12 complete orthodontic treatments. The mean duration of treatment period with a bonded distalizer was 6.4 months. All cases were adults with unilateral Class II malocclusion managed with a hybrid approach as a part of Invisalign® comprehensive treatment. Results showed that such perspective practice is feasible for 3D design and in-office 3D printing of a personalized distalizer. Results also showed no clinically significant differences between both studied biopolymers. The paper discusses an evaluation of such personalized distalizer functionality with regard to the current state of the art and compares to conventional prefabricated alternatives like a Carriere® Distalizer™ appliance. Research showed a preference of patients towards transparent biocompatible photopolymer instead of the white A2 shade. The paper concludes that additive manufacturing from dental resins is a viable method in personalization and in-office 3D printing of orthodontic auxiliaries, particularly distalizers. New materials for orthodontic 3D printing endow enhanced individualization, thus more efficient treatment.

The digital alveolar cast: A revised approach to an old concept

An alveolar cast is recommended for the fabrication of specific fixed dental prostheses. The analog workflow for such casts is labor-intensive, time-consuming, and highly skill dependent. Advancements in digital technologies are bringing new, efficient, and streamlined protocols for dental practice. This article presents a digital workflow for the fabrication of an alveolar cast by using computer-aided design and computer-aided manufacturing (CAD-CAM)technologies.

A vat-polymerized 3-dimensionally printed dual-material occlusal device: A dental technique

A technique to additively manufacture an occlusal device by using a completely digital workflow is described. Using a computer-aided design program, information captured with an intraoral scanner was used to additively manufacture a dual-material occlusal device by using a vat-polymerization printer. This technique allows for the combination of 2 different materials, resulting in an occlusal device with a resilient intaglio and a hard resin exterior surface. Advantages of the resulting occlusal device compared with a single-material device include improved patient acceptance and comfort, better fit, and minimal adjustments to ensure fit.

Fabricating a custom tray for an impression of multiple abutment teeth by using an open-source software program

Although intraoral scanners have gained in popularity, the traditional impression technique with a custom tray is still useful, particularly when making a definitive impression of multiple abutment teeth. A custom tray can be fabricated with a dental software program, avoiding the disadvantages of the manual laboratory procedures. However, additional module purchasing is necessary. This article presents a digital workflow for designing a custom tray by using an open-source software program.