A digital workflow for modeling of custom dental implants

Abstract

Modern dental treatment with standard screw-type implants leave some cases unaddressed in patients with extreme jaw bone resorption. Custom-made subperiosteal dental implant could be an alternative treatment modality to sinus lift, nerve lateralization or zygomatic implant techniques. Subperiosteal dental implants were utilized for many years to treat such patients. A combination of traditional subperiosteal implant designs with current advancements in 3D imaging, design and printing allow to reduces treatment time and provides abutments for prostheses in cases where other techniques do not provide satisfactory results. The data manipulation and design software are important aspects in the manufacturing of custom implants. Programs that are specialized for industrial or medical design typically cost tens of thousands of US dollars. In this work I establish and test steps for design and production of a custom medical device (subperiosteal implant) from patient computed tomography (CT) data. Work stages to be defined are: selection of necessary software, CT data processing, 3D virtual model creation, modeling technique for custom implant and data file preparation for printing. Patient CT data was successfully converted into a watertight STL (Standard Tessellation Language) model of the maxilla. Error corrections and design were completed using freely available programs from Autodesk Inc.. The implant was produced in Ti64 (a type 5 titanium alloy) using three-dimensional (3D) printing DMLS (direct metal laser sintering) process. The avoidance of high cost software makes this treatment modality more accessible to smaller clinics or mid-size production facilities and subsequently more available to patients.

Custom-made 3D printed subperiosteal titanium implants for the prosthetic restoration of the atrophic posterior mandible of elderly patients: a case series

“…For all these patients, and in all these situations, subperiosteal implants may be an alternative, due to the digital revolution and the advent of modern digital technologies in dentistry [34][35][36][37]46]. CBCT allows acquisition of 3D data of the patient's residual bone volume, with considerable accuracy, and a low dose of radiation directed exclusively at the area of interest [27,47].…”

“…CBCT allows acquisition of 3D data of the patient's residual bone volume, with considerable accuracy, and a low dose of radiation directed exclusively at the area of interest [27,47]. The data acquired with the CBCT is then re-elaborated with appropriate reconstruction software, which allows generation of a virtual bone model of the area of interest [34][35][36][37]. Capturing an optical impression of the dentate arches allows modelling of a virtual diagnostic wax-up.…”

“…Capturing an optical impression of the dentate arches allows modelling of a virtual diagnostic wax-up. Finally, the superimposition of bone and dental models, together with the virtual wax-up, makes it possible to design and model custom-made subperiosteal implants, designed and conceived specifically for the patient's needs, both as a bone-supported structure and as a prosthetic emergency [34][35][36][37]. These 3D-printed implants represent a possible alternative solution for the rehabilitation of the atrophic posterior mandible of elderly patients who do not want or cannot undergo traditional regenerative techniques, preparatory to insertion of classical endosseous implants [34][35][36][37].…”

“…a Buccal view of the framework; b the zirconia structure, buccal view; c the zirconia structure, lingual view as porous, hollow objects with interconnections, tunnels and crevices. It is possible to manufacture titanium or titanium alloy implants, whether standard endosseous [29] or custom-made subperiosteal [34][35][36][37].…”

“…This allows the opportunity to revisit some old concepts, such as the placement of subperiosteal implants, and reinterpret them in a new technological context based on consolidated anatomical and physiological principles [34][35][36]. The reduction of treatment to a single surgical session, lower costs for the patient and, above all, the precision that makes the method more predictable and safer in the short term have brought the attention of clinicians back to the use of subperiosteal implants, particularly for the management of complex atrophies such as in the posterior mandible of elderly patients [36,37].…”