title: Biomechanical evaluation of subcrestal dental implants with different bone anchorages.
abstract: This study evaluated the biomechanical influence of apical bone anchorage on a single subcrestal dental implant using three-dimensional finite element analysis (FEA). Four different bone anchorage designs were simulated on a posterior maxillary segment using one implant with platform switching and internal Morse taper connection as follows: 2 mm subcrestal placement with (SW) or without (SO) the implant apex engaged into the cortical bone or position at bone level with anchorage only in the crestal cortical (BO) bone or with bicortical fixation (BW). Each implant received a premolar crown, and all models were loaded with 200 N to simulate centric and eccentric occlusion. The peak tensile and compressive stress and strain were calculated at the crestal cortical, trabecular, and apical cortical bone. The vertical and horizontal implant displacements were measured at the platform level. FEA indicated that subcrestal placement (SW and SO) created lower stress and strain in the crestal cortical bone compared with crestal placement (BO and BW models). The SW model exhibited lesser vertical and horizontal implant micromovement compared with the SO and BO models under eccentric loading; however, stress and strain were higher in the apical cortical bone. The BW model exhibited the lowest implant displacement. These results indicate that subcrestal placement decreases the stress in the crestal cortical bone of dental implants, regardless of apical anchorage; however, apical cortical anchorage can be effective in limiting implant displacement. Further studies are required to evaluate the effects of possible remodeling around the apex on the success of subcrestal implants.
authors.affiliation: Department of Restorative Dentistry, Dental School, Universidade Federal de Juiz de Fora, Juiz de Fora, MG, Brazil.
authors.forename: Bruno Salles
authors.initials: BS
authors.lastname: Sotto-Maior
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Camila de Andrade
authors.initials: Cde A
authors.lastname: Lima
authors.affiliation: Department Health Sciences Center, Unigranrio University, Duque de Caxias, Rio de Janeiro, Brazil.
authors.forename: Plínio Mendes
authors.initials: PM
authors.lastname: Senna
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Germana de Villa
authors.initials: Gde V
authors.lastname: Camargos
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
authors.forename: Altair Antoninha
authors.initials: AA
authors.lastname: Del Bel Cury
mesh_terms: D000539:Alveolar Process; D001696:Biomechanical Phenomena; D019245:Compressive Strength; D003758:Dental Implantation, Endosseous / Q000379:methods*; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008422:Materials Testing; D008954:Models, Biological; D012016:Reference Values; D015203:Reproducibility of Results; D013499:Surface Properties; D053441:Suture Anchors; D013718:Tensile Strength