Initially, digital impression techniques were used in the field of prosthodontics for the fabrication of dental prostheses. Clinical studies showed that dental prostheses made with the help of this technology showed more accuracy in comparison with traditional impressions.
These good results contributed to the fact that digital impression scanners are becoming more and more mainstream in various fields of dentistry, usually with labs taking the lead and their practices following suit after.
Dental specialists that were first-movers are even developing and promoting specific impression taking protocols and techniques, for instance, there is a corrective primary impression technique and a strategy for scanning fully edentulous patients.
If we look at the process of taking digital impressions in general we will see that there are a few common steps, and they all are fully digitalized:
- First — entering patient information into the scanner software;
- Second — scanning upper and lower arches;
- Third — right and left bite scanning;
- Fourth — sending results to the person working on the design or treatment plan.
Let’s see how digital impressions are taken in different fields of dentistry.
Digital impressions in orthodontics
Orthodontists use digital impressions to create 3D models of the position of the teeth for proper treatment planning and correct placement of the treatment appliances.They either scan the patient directly or they digitize a gypsum model with a desktop scanner. Once the digital model is created, an orthodontist can open it in dedicated orthodontic planning software to determine the most accurate and functional way to place braces, clear aligners, or other retainers, in order to get the desired outcome. In some cases, an orthodontist will choose to combine digitally taken impressions with 3D panoramic X-ray. They do this in order to ensure there are no anatomical problems before initiating treatment.
Digital impressions for dentures
creation always starts with impression taking, either in conventional or digital form. Even though the conventional way is still the default for most dentists and denturists, digital impressions are becoming more and more popular, because digital can enable a faster, more comfortable and cheaper workflow. A digital impression can (as for other indications) be taken from a gypsum model or impression tray with a desktop scanner, or directly with the patient, with an intraoral scanner
. Taking a scan directly from an edentulous patient was previously seen as challenging, because of the soft tissue. The soft tissue and vestibular area of edentulous patients is moveable, which makes it hard for the scanner to capture. However, scanners are becoming better and better in capturing the movement of the soft tissue and research
now shows that fully digital impressions for complete dentures can provide great outcomes. The right technology combined with the right scan technique
seems to make the way for entirely digital denture workflows, even for fully edentulous patients.
Digital implants impressions
Digital impressions can also be used to plan where to place the implants for the best prosthetic outcome. This is called Prosthetically Driven Implant Planning. This digital implant impression usually needs to be combined with a cone beam scan in order to get the full picture and start treatment planning. Once the design is validated, the doctor aligns the (digital) impression and the x-ray scan, and presents the patient with the treatment plan. When the doctor chooses to do a fully digital workflow, they may opt to use their digital implant scan for creating a surgical guide, too. The use of a guide during surgery to some doctors means a safer procedure that will reduce operating time.