A dental crown functions as a tooth-shaped cap designed to cover and restore a damaged tooth. Its primary purpose involves strengthening a weak tooth, protecting a cracked tooth from further damage, or restoring a worn-down tooth to its original form. Dental crowns also serve to cover dental implants or teeth that have undergone root canal treatment, improving both appearance and chewing function. This restoration method has evolved significantly with the introduction of modern technologies like 3D printing.
The Manufacturing Process for a 3D Printed Crown
The journey of creating a 3D printed crown begins with a digital intraoral scan of the patient’s mouth. This advanced scanning technique replaces traditional, often uncomfortable, putty impressions by capturing high-resolution digital images of the tooth anatomy. The scan generates a precise 3D model of the tooth.
Following the digital scan, the computer-aided design (CAD) phase commences. Dental professionals use specialized CAD software, such as exocad, to design the crown digitally, ensuring it perfectly matches the patient’s bite alignment, shape, size, and surface texture. This digital blueprint is then sent to a 3D printer for additive manufacturing. The printer builds the crown layer by layer, transforming liquid resin into a solid restoration.
Once the printing is complete, the crown undergoes several post-processing steps. This typically includes washing to remove any unpolymerized resin, followed by curing with ultraviolet (UV) light to fully harden the material. The crown is then carefully polished and has any support structures removed before it is ready to be fitted by the dentist.
Materials Used in 3D Printed Crowns
The main materials for 3D printed dental crowns are specialized dental-grade resins. These are biocompatible polymers formulated to be safe for use within the human body. Different formulations of these resins exist, tailored for specific applications.
Some resins are designed for interim crowns and bridges, offering resistance to bite pressure and wear. Other resins are developed for more durable, long-term solutions, providing enhanced strength and biocompatibility. These resins exhibit excellent plasticity, allowing for the creation of intricate crown designs, and also offer good color rendition to closely match natural tooth shades.
Research is exploring the use of 3D printable ceramics, such as zirconia, which are known for their strength and aesthetic properties. While metals can also be 3D printed for dental applications, resins currently remain the most widely used material for printed crowns due to their versatility and ease of processing.
How 3D Printed Crowns Differ from Traditional Crowns
A key difference between 3D printed crowns and those made by traditional methods lies in the speed of production. 3D printing enables same-day crowns, allowing patients to receive their permanent restoration in a single visit. Traditional crowns, whether lab-milled or cast, typically involve multiple appointments and can take several days to weeks to fabricate due to the need for physical impressions and external lab processing.
The precision and fit of 3D printed crowns are enhanced by the digital workflow. Digital scanning and computer-aided design allow for high accuracy, resulting in a custom-fitted restoration that minimizes inconsistencies. Traditional methods, which rely on manual impressions, may introduce slight variations during the fabrication process.
Cost considerations also distinguish these crown types. 3D printed crowns can offer cost savings due to reduced labor and material expenses. In contrast, traditional crowns can be more expensive due to the labor-intensive milling processes and associated lab fees.
Regarding aesthetics, resin-based 3D printed crowns offer good color matching to natural teeth. However, traditional crowns made from porcelain, ceramic, or porcelain-fused-to-metal are considered the standard for aesthetics, mimicking the natural appearance and translucency of teeth. Some 3D printed resins may require additional staining to achieve optimal aesthetic quality for long-term restorations.
Durability and Patient Care
The expected lifespan of a 3D printed crown can vary based on the resin material used. Some advanced 3D printed crowns are designed for permanent use and can last between 10 to 15 years with proper care. However, many 3D printed crowns are still better suited for temporary or medium-term applications. This is because resin-based crowns may not yet match the long-term wear resistance and fracture toughness of traditional materials.
Patient care for 3D printed crowns is consistent with recommendations for any dental crown. Maintaining good oral hygiene is important, including regular brushing and flossing to prevent plaque buildup around the crown and surrounding gum tissue. Patients should avoid chewing on hard objects to minimize the risk of chipping or damaging the crown. Regular dental check-ups are advised to monitor the crown’s condition and overall oral health.