What materials are used in digital smile design

Okay, so I’m looking into getting digital smile design (DSD) done, and I’m trying to wrap my head around the whole process. I understand it involves a lot of technology, which is cool. But what I don’t understand is what actual physical materials are used at different stages.

I’m not just talking about the final veneers or crowns – although that IS important, and I’d love to know what options are typically offered there! But I’m also curious about the materials used for the mock-ups. I’ve seen pictures of people with these temporary smiles placed on their teeth to preview the design, and they look pretty real. What are those made of? Are they all the same material, or does it vary?

And then what about the initial impressions or scans? Are they still using that gooey impression material for the initial molds, or is it all digital now? If it’s digital, what kind of scan technology is used, and does that involve any special powders or coatings on the teeth?

Basically, I want to know the whole materials rundown, from start to finish. I’m hoping to get a better understanding of the different stages and maybe even discuss the pros and cons of each material with my dentist.

Answer

Digital Smile Design (DSD) involves a range of materials used both in the planning/design phase and in the physical mock-up and restorative phases. Here’s a breakdown of the materials involved, categorized by their application:

I. Planning and Design Phase:

• Digital Cameras and Scanners: High-quality digital cameras and intraoral scanners are fundamental for capturing accurate data. These aren’t materials in the traditional sense, but critical equipment:

  • Digital Cameras (DSLR or Mirrorless): Used to take high-resolution photographs of the patient’s face, smile, and teeth from various angles (frontal, profile, occlusal, etc.). They require:
    • Lenses: Macro lenses are often preferred for capturing detailed images of teeth.
    • Lighting: External flashes and diffusers are crucial for controlled and consistent lighting.
  • Intraoral Scanners: These devices directly scan the teeth and surrounding soft tissues, creating a 3D digital model. Examples include:
    • Powder-free scanners: Usually preferred for patient comfort and ease of use.
    • Scan bodies: Used with dental implants to accurately locate the implant position in the digital model.
• Software: Specialized DSD software is used to analyze the images and scans, create the new smile design, and communicate with the lab or milling unit.
  • DSD Software: Programs such as Planmeca Romexis Smile Design, Exocad Smile Creator, 3Shape Smile Design, or others. These software packages are material agnostic but essential for virtually creating the smile.

II. Mock-Up Phase (Provisional Phase):

This phase involves creating a temporary representation of the designed smile directly in the patient’s mouth.

• Provisional Materials (Acrylics and Composites): These materials are used to fabricate a temporary mock-up based on the digital design.
  • Bis-acryl Composites (e.g., Protemp, Luxatemp): Commonly used for temporary crowns and bridges. They offer good esthetics, strength, and ease of use. They are dispensed from cartridges and self-cure.
  • Acrylic Resins (e.g., Trim, Jet): Can also be used, but generally less preferred than bis-acryl composites due to lower esthetics and higher shrinkage. They are often used when the mock-up requires adjustments or additions.
  • Flowable Composites: Useful for small adjustments or additions to the mock-up, providing good color matching and flowability.
• Impression Materials (for indirect mock-ups): If an indirect mock-up is created on a model outside the mouth, impression materials are used to transfer the design to the patient’s mouth.
  • Alginate: A common and inexpensive impression material used for diagnostic casts.
  • Polyvinyl Siloxane (PVS) or Polyether: More accurate impression materials used for detailed impressions of the teeth and surrounding tissues. Used for creating accurate models for indirect mock-ups.
• Clear Matrices/Stents: A clear template created from a model of the designed smile. This is loaded with the provisional material and placed in the patient’s mouth to transfer the mock-up.
  • Vacuum-formed Thermoplastic Sheets: Used to create the clear matrix/stent. The sheet is heated and then vacuum-formed over the model of the designed smile.
• Bonding Agents (for attaching the mock-up):
  • Etchant (Phosphoric Acid): Used to roughen the tooth surface for better bonding.
  • Bonding Resin: Applied to the etched tooth surface to create a strong bond between the tooth and the provisional material. Usually a self-etch adhesive is used for this phase for expediency.

III. Restorative Phase (Permanent Restoration):

This phase involves creating the final, permanent restorations based on the approved smile design. The choice of material depends on the clinical situation, patient preferences, and desired esthetics.

• Ceramics (Porcelain): The most commonly used material for esthetic restorations due to their excellent esthetics, biocompatibility, and durability.
  • Feldspathic Porcelain: Highly esthetic, but less strong than other ceramics. Ideal for veneers where minimal preparation is required.
  • Lithium Disilicate (e.g., e.max): Offers a good balance of esthetics and strength. Suitable for veneers, inlays, onlays, and crowns. Can be pressed or milled.
  • Zirconia: Very strong and durable. Can be used for crowns and bridges, especially in the posterior region. Esthetics have improved with multilayered and highly translucent zirconia.
  • Porcelain Fused to Metal (PFM): A metal substructure covered with porcelain. Strong but less esthetic than all-ceramic restorations. Less commonly used today due to the superior esthetics of all-ceramic options.
• Composite Resin: Can be used for direct restorations, but less commonly used for extensive smile makeovers due to lower durability and esthetics compared to ceramics.
  • Direct Composite: Applied directly to the teeth in layers, sculpted, and light-cured.
  • Indirect Composite: Fabricated outside the mouth and then bonded to the teeth. Offers better strength and esthetics compared to direct composite.
• Bonding Agents (for permanent restorations):
  • Etchant (Phosphoric Acid): Used to etch the enamel.
  • Primer: Applied to the dentin to improve bonding.
  • Bonding Resin: Used to bond the restoration to the tooth structure. The specific bonding agent used depends on the type of restoration and the manufacturer’s instructions. Resin cements are typically used.
• Dental Implants (if necessary):
  • Titanium: Most common material for dental implants due to its biocompatibility and osseointegration properties.
  • Zirconia: An alternative material for dental implants, offering improved esthetics and biocompatibility.
• Abutments (for implant-supported restorations): Connect the implant to the crown or other restoration.
  • Titanium: Strong and durable.
  • Zirconia: Offers improved esthetics, especially in the anterior region.
• Cements (for luting restorations):
  • Resin Cements: Offer high bond strength and excellent esthetics. Commonly used for ceramic restorations.
  • Glass Ionomer Cements: Fluoride-releasing and bond chemically to tooth structure. Less strong and esthetic than resin cements.
  • Resin-Modified Glass Ionomer Cements (RMGIC): Combine the benefits of both resin and glass ionomer cements.

IV. Laboratory Materials and Equipment:

These materials and equipment are used in the dental laboratory to fabricate the final restorations.

• Dental Stone (Gypsum): Used to create models of the patient’s teeth and surrounding tissues.
• Investment Materials: Used to create molds for casting metal or pressing ceramic restorations.
• Casting Alloys (for PFM restorations): Used to create the metal substructure for PFM restorations.
  • Noble Alloys (e.g., Gold, Platinum, Palladium): Offer excellent biocompatibility and corrosion resistance.
  • Base Metal Alloys (e.g., Nickel-Chromium, Cobalt-Chromium): Less expensive than noble alloys, but may have lower biocompatibility.
• Ceramic Powders (for layering porcelain): Used to create the esthetic layers of porcelain on ceramic restorations.
• CAD/CAM Blocks (for milled restorations): Prefabricated blocks of ceramic or composite resin that are milled into the desired shape using CAD/CAM technology.
• Glazes and Stains: Used to customize the shade and characterization of ceramic restorations.
• Dental Furnaces: Used to fire ceramic restorations and achieve the desired strength and esthetics.
• Milling Machines: Used to mill restorations from CAD/CAM blocks.
• 3D Printers: Used to print models, surgical guides, and temporary restorations.
• Laser Sintering Machines: Used to create metal frameworks for restorations.

The specific materials used in a DSD case will depend on the patient’s individual needs and preferences, the dentist’s expertise, and the available technology. The trend is towards using more digital workflows and biocompatible, esthetic materials like lithium disilicate and zirconia.