Research has been conducted into the viability of 3D printed removable partial dentures (RPD) in comparison to conventionally cast metal RPDs.
The outcome of the month-long clinical trial demonstrated that not only were the 3D printed dentures a viable solution – but that they were preferred overall. For the study, the researchers used a selective laser melting 3D printer to create dentures to compare with a control group of cast metal dentures.
The participants, who all suffered from edentulism meaning they were toothless in some degree, were selected randomly to use each denture for different periods over the 30 day trial.
The research was conducted at McGill University in Montreal, with support from the University of Rio Grande do Sul in Brazil and King Saud University of Saudi Arabia.
The research paper explains the purpose of the trial was to prove the viability of 3D printing as a viable production method in dentistry,
Clinical trials are needed to evaluate this new technology in RPD fabrication before its use can be recommended
The researchers explain the selective laser melting (SLM) AM technique, which involves melting metal powder with lasers, is beneficial to casting methods as it is less prone to error. 3D printing the RPD involves 3D scanning the patient’s mold and designing the prosthesis with CAD software. The design is then sent digitally to the 3D printer machine and with more reliance on digital manufacturing, the team believes the process is more accurate and at lower risk of human error.
In this study, the group used a Phenix Systems PM100T Dental 3D printer to create the RPD having 3D scanned the molds using a 3Series device by Dental Wings. Phenix Systems is a metal 3D printing company based in France and is now owned by U.S company 3D Systems. The dentures were digitally designed using 3Shape’s CAD Points software which has also been supported by 3D Systems.
Elsewhere in the field of digital dentistry, U.S company EnvisionTEC has announced its 3D printed dentures have been granted FDA approval.
“Fewer complaints and more compliments”
With an average age of 65.6 years, the researchers conducted the trial with 12 participants initially although 3 did not complete. Of the 9 that finished the trial, 5 preferred the 3D printed RPD, 3 had no preference and 1 preferred the conventionally cast RPD.
The team evaluated the patient’s results by conducting a McGill Denture Satisfaction questionnaire. Using this instrument, they found that “participants reported fewer complaints and more compliments when they were using the laser-sintered RPDs than when using the cast RPDs.”
Additionally the research group noted, “participants were significantly more satisfied with the laser-sintered prostheses than the cast prostheses in terms of general satisfaction, ability to clean and speak, comfort, masticatory ability, masticatory efficiency, and oral condition.”
Despite these results, the paper does point out some of the inhibiting factors of the technology, such as high initial costs for use of the machine and required time and expertise needed to learn the technology. Also noted that some patient’s will not be applicable for the technology due to current limitations in design software. The researchers did also understand there were limitations with their study in terms of small sample size and a relatively short sample period. However were able to conclude that,
The use of laser sintering technology for the fabrication of RPDs may lead to higher short-term satisfaction for patients with partial edentulism than conventional methods.
The paper, titled ‘Patient satisfaction with laser-sintered removable partial dentures: A crossover pilot clinical trial’, is published in The Journal of Prosthetic Dentistry.
Featured image shows 3D Systems Rapid Printing Dental Solutions. Photo by Michael Petch.