dental implants

A DICOM file is the standard file type for medical data, defined by the National Electrical Manufacturer’s Association (NEMA), that all CBCT machines are capable of outputting. In addition to the image data, each file contains information about the patient, acquisition date and method and the spatial location of the image data. Each DICOM file represents an image section, and the entire collection of DICOM files makes up the 3D representation of an implant site.13 Because of the patient data associated with each DICOM file, practitioners should take care to follow HIPAA guidelines to secure them, especially when they are exported from their picture archiving and communication system (PACS).

Intraoral scans can be exported into 3D model file formats such as STL, OBJ, 3MF and more. While each format has its unique properties, the STL has become the most widely used format for 3D models because of its relatively small file size, speed of export and wide-ranging compatibility. Disadvantages of the STL file type for dentistry are that it does not contain color or scale information, meaning its units of measurement are arbitrary.

Despite these drawbacks, adoption of the STL is so wide that most current dental scanning software and device manufacturers use the file type. Due to its established use in dentistry, this paper refers to 3D model files as STLs.

Intraoral Scanners

There are many intraoral scanners on the market, each with software capable of doing simple to complex dental treatments digitally. Though an in-office intraoral scanner streamlines the process, many dental labs can scan conventional models or impressions and provide an STL file for a fee. For practitioners looking to purchase an intraoral scanner, factors to consider when selecting one include: l Integration with other existing practice technologies: Software suites like Romexis, DTX Studio and Dolphin Imaging support intraoral scanning. If a practice is already using such a software but is not utilizing the intraoral scanning capabilities, acquiring a manufacturer-supported intraoral scanner would decrease the setup and training time. l Practice use case: Different scanners may be optimized for different procedures. For example, the iTero Element series of scanners would be ideal for Invisalign users due to the tight softwarehardware integration, as both are made by Align Technologies. l Form factor: In addition to considering an intraoral scanner’s size for a patient’s mouth, practitioners should also evaluate whether a scanner comes attached to a proprietary cart, the length and type of cable, size of cradle and device ergonomics. l Manufacturer support: Terms of support and its cost influence practitioner confidence and can minimize downtime. l Cost: New intraoral scanners cost between $9,000 to $50,000 per unit. Support packages range from free to hundreds of dollars a month. l User interface and experience: While some manufacturers offer a “white glove” experience where all support concerns are mitigated, others provide a “bare bones” approach that encourages the end user to create custom solutions.

Some examples of intraoral scanners include 3Shape Trios 4, Planmeca Emerald S, Align Itero Element D, Carestream Dental CS 3700 and Medit i700. The images shown in this review are from 3Shape’s Trios 3 intraoral scanner.

Intraoral Scanning

For restoratively driven implant placement, three intraoral scans are needed: an intraoral scan of the arch containing the implant site (Figs. 1), an intraoral scan of the opposing arch and an intraoral scan of the bite (Figs. 1). This can be used to create a virtual articulator and a digital wax-up. The digital waxup must have the proper dimensions, be in the correct occlusal plane and occlusion, and most importantly, be in the correct long- axis. Ideally the tooth should be missing in the intraoral scan. However, for immediate implant cases, the tooth to be replaced can be digitally removed using the planning software.

It is crucial that the intraoral scan is accurate, since the fit of the surgical guide and the placement of the implant depend on it. Digital impressions obtained from intraoral scanners appear to be as accurate as analog.14–17 t