Dr Kunal Shah describes a case where he used an intraoral scanner to treat a case of chronic apical periodontitis
A 60-year-old patient presented after receiving a recommendation from another patient. He was a regular attendee to his usual practice and had a clear medical history with no significant issues. He reported having pain in his lower right quadrant, and his LR6 was experiencing pain on biting, sensitivity to hot and cold temperatures, and tenderness to percussion. The diagnosis was chronic apical periodontitis.
Multiple treatment options were discussed to ascertain how best to move forward. The first option was to have no treatment at all, and to let the condition remain how it is. The second option was to extract the tooth and to restore the space using an implant/partial denture/bridge. The third option was to save the tooth with root canal treatment and place a crown.
It was also stated that regardless of the course of action chosen, the patient would need to improve oral hygiene and attend appointments with a dental hygienist to manage the periodontal condition effectively.
The patient was provided with information about multiple options for restoring the space if extraction was chosen, and the different options for crowning, too.In the end, he opted for the most conservative solution of root canal treatment and subsequent crowning of the tooth.
The first step was to perform the root canal treatment. This was a highly complex case that required three appointments to complete effectively.
After the successful root canal was performed, a core was built up. Following this, a digital workflow was used rather than traditional analogue methods.
The CS 3600 intraoral scanner from Carestream Dental was used to scan the crown preparation and the entire quadrant.
Taking impressions this way and with a system like the CS 3600 is truly fantastic. The best workflow with the scanner is to start by scanning the jaw you worked on. The occlusal surfaces should be scanned first, and then the lingual and buccal aspects should be recorded. By following this order, you capture all possible data on the first time. After this, the opposing jaw and then the bite should be scanned.
The scan was then refined to get the clearest possible image. The patient was showed this image, and because it was so accurate, he was impressed with the standard of technology we used. The CS 3600 intraoral scanner works well for this type of case, because it provides high quality scans in a quick and easy way. The imaging software allows dentists to extract still images from the continuous scanning as well, making it simple to identify any areas that need to be scanned again
for clarity. This also means that clinicians can easily identify any prep designs that need adjustment.
The impression was then uploaded to CS Connect and sent to the laboratory within minutes, prescribed with a normal lab docket (in a digital format). This means that laboratory technicians can start to create the restoration immediately.
A number of crown types are available, but we decided on a zirconia crown because of both personal preference and its superior material strength. The laboratory designed and milled the crown, which was sintered overnight. It was then glazed and polished and sent back, with a turnaround time of just slightly over 24 hours. This meant we could work within any time constraints and also complete treatment for the patient without a long wait.
At the next appointment, the crown was seated, tried in and fitted for marginal integrity. The crown was an exact fit, had good interproximal contacts and ideal occlusion. The patient was very happy with the fit and the aesthetics. The crown was cemented using RelyX Ultimate adhesive resin cement from 3M Oral Care, and any excess was removed. The occlusion was then checked and, because of the nonoperator-sensitive digital workflow, it was spot-on.
Using an intraoral scanner instead of analog impression materials offers many advantages.
Traditional impressions for crown preparations are typically achieved using an addition-cured silicone or a polyether. These can present certain challenges, because understanding the product is incredibly important. The working and setting time of these products vary, and drags in the impression are common unless you know exactly how to use them.
Polyether tends to be more accurate than addition-cured silicone, but it’s also important to consider dimensional stability, because analog impressions may also morph during delivery to the laboratory, compromising accuracy.
The dental nurse and dentist must work in total harmony when using analog impression materials; otherwise, outcomes may be compromised through human error.
On the other hand, digital methods are far more reliable because they overcome these challenges. There is no chance of drag, so impressions are more accurate, and because digital acquisition isn’t technique-sensitive, it makes for far more predictable results. The workflow is streamlined from surgery to lab, and time is maximised.
There are some limitations to intraoral scanners, however, and the initial investment is offputting to some. Subgingival margins can also be difficult to scan, but the CS 3600 has a hybrid aspect that overcomes this limitation.
The main benefit of the CS 3600 scanner is that it is an open system, so it can be used alongside and communicate with a vast array of other technologies
It’s a convenient, small piece of kit that requires little space, is extremely user-friendly, and has no after-care cost.