21 December 2022

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Digital Smile designed computer-aided surgery versus traditional workflow: Which is better in “All on Four” rehabilitations?

Lorenzo Breschi

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Cutting edge technologies are now on the agenda for every dentist. Digital protocol makes a completely virtual planning of the exact position of the fixtures, allowing for accurate flapless surgery procedures — mini-invasive surgery — and it is also possible to use virtually planned prostheses realized with Computer-Aided Design/Computer-Aided Manufacturing, CAD/CAM. 

To understand whether these methods are effective and efficient, Francesca Cattoni et al. conducted a randomized clinical trial with four years of follow up, comparing the traditional “All on Four” technique with digital smile designed computer aided “All on Four” rehabilitations. 

The aim of the study was to describe and assess two protocols on two homogeneous groups of patients, taking into consideration: marginal bone level values at 12, 24, 36 and 48 months by radiographic evaluation; implant and prosthetic complications and failures; patient’s perception of the procedures used; evaluation of operative and post-operative pain.

Materials and methods

Fifty patients were recruited for the study and, after checking the inclusion and exclusion criteria, they were randomly divided into two groups. Half of the patients went through the implant-prosthetic protocol with the digital approach.  The remaining 25 underwent the traditional “All on Four” protocol. The first two appointments were the same in both groups, from the third appointment onwards the two protocols followed different paths, depending on whether they were digital or traditional. 

Results

After four years, the traditional protocol obtained 98% of success and 100% for the digital protocol. At each time interval researchers noted a significant difference in peri-implant crestal bone loss between the two groups, with an average marginal bone loss at four years of 1.12 ± 0.26 mm in the traditional group and 0.83 ± 0.11 mm in the digital group. 

Patients in the digital group have judged the immediate loading (92%), digital smile preview (93%), the mock-up test (98%) and guided surgery (94%) as very effective. All patients treated with a digital method reported lower values of during-surgery and post-surgery pain compared to patients rehabilitated using traditional treatment.

Conclusion 

The researchers concluded that the totally digital protocol described in the study represents a valid therapeutic alternative to the traditional “All on Four” protocol for implant-supported rehabilitations of edentulous dental arches. 

F. Cattoni, L. Chirico, A. Merlone, M. Manacorda, R. Vinci, E.F. Gherlone. “Digital Smile Designed Computer-Aided Surgery versus Traditional Workflow in ‘All on Four’ Rehabilitations: A Randomized Clinical Trial with 4-Years Follow-Up.” Int J Environ Res Public Health 2021;18(7); 3449.