Comparison between all-on-four and all-on-six treatment concepts and framework material on stress distribution in atrophic maxilla: A prototyping guided 3D-FEA study.
We evaluated two treatment concepts for the rehabilitation of moderate atrophic maxilla with dental implants (all-on-four and all-on-six) and the effect of framework material on the stress distribution of implant-support system. A three-dimensional finite element model based on a prototype was built to simulate an entirely edentulous maxilla with moderate sinus pneumatization that was rehabilitated with a full-arch fixed dental prosthesis. Four standard implants were positioned according to the all-on-four concept and four standard implants and two short implants were placed according to the all-on-six concept. Three framework materials were evaluated: cobalt-chrome (CoCr), titanium (Ti) and zirconia (Zr), totalizing six groups. A unilateral oblique force of 150N was applied to the posterior teeth. The von Mises (σVM), maximum (σmax) and minimum (σmin) principal stress and displacements were obtained. All-on-six showed smaller σmin, σVM and σmax values on the cortical bone, implants and trabecular bone, respectively. All-on-four exhibited higher displacement levels. Ti presented the highest stress values on the cortical bone, implants, abutments, prosthetic screws and displacement levels. In conclusion, the all-on-six approach and framework stiffer materials showed the most favorable biomechanical behavior. However, the stress values did not exceed the bone resistance limits for both treatment concepts.
Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Sao Paulo, Brazil.
Cláudia Lopes Brilhante
CL
Bhering
Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Sao Paulo, Brazil.
Marcelo Ferraz
MF
Mesquita
Renato Archer Information Technology Center, Campinas, Sao Paulo, Brazil.
Daniel Takanori
DT
Kemmoku
Renato Archer Information Technology Center, Campinas, Sao Paulo, Brazil.
Pedro Yoshito
PY
Noritomi
Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Sao Paulo, Brazil.
Rafael Leonardo Xediek
RL
Consani
Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Sao Paulo, Brazil. Electronic address: vbarao@unicamp.br.
Valentim Adelino Ricardo
VA
Barão
D001284:Atrophy; D001863:Bone Screws; D000071556:Cancellous Bone / Q000473:pathology; D000071538:Cortical Bone / Q000473:pathology; D000044:Dental Abutments; D015921:Dental Implants; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D008437:Maxilla / Q000473:pathology*; D008953:Models, Anatomic; D013314:Stress, Mechanical
D015921:Dental Implants
All-on-four; All-on-six; Finite elements analysis; Framework material; Short implant