Effect of platform connection and abutment material on stress distribution in single anterior implant-supported restorations: a nonlinear 3-dimensional finite element analysis.
BACKGROUND
Although various abutment connections and materials have recently been introduced, insufficient data exist regarding the effect of stress distribution on their mechanical performance.


OBJECTIVE
The purpose of this study was to investigate the effect of different abutment materials and platform connections on stress distribution in single anterior implant-supported restorations with the finite element method.


METHODS
Nine experimental groups were modeled from the combination of 3 platform connections (external hexagon, internal hexagon, and Morse tapered) and 3 abutment materials (titanium, zirconia, and hybrid) as follows: external hexagon-titanium, external hexagon-zirconia, external hexagon-hybrid, internal hexagon-titanium, internal hexagon-zirconia, internal hexagon-hybrid, Morse tapered-titanium, Morse tapered-zirconia, and Morse tapered-hybrid. Finite element models consisted of a 4×13-mm implant, anatomic abutment, and lithium disilicate central incisor crown cemented over the abutment. The 49 N occlusal loading was applied in 6 steps to simulate the incisal guidance. Equivalent von Mises stress (σvM) was used for both the qualitative and quantitative evaluation of the implant and abutment in all the groups and the maximum (σmax) and minimum (σmin) principal stresses for the numerical comparison of the zirconia parts.


RESULTS
The highest abutment σvM occurred in the Morse-tapered groups and the lowest in the external hexagon-hybrid, internal hexagon-titanium, and internal hexagon-hybrid groups. The σmax and σmin values were lower in the hybrid groups than in the zirconia groups. The stress distribution concentrated in the abutment-implant interface in all the groups, regardless of the platform connection or abutment material.


CONCLUSIONS
The platform connection influenced the stress on abutments more than the abutment material. The stress values for implants were similar among different platform connections, but greater stress concentrations were observed in internal connections.
Doctoral student, Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil. Electronic address: m110058@dac.unicamp.br.
Marco Aurélio
MA
Carvalho
Professor, Department of Restorative Dentistry, Federal University of Juiz de Fora, Juiz de Fora, Minas Gerais, Brazil.
Bruno Salles
BS
Sotto-Maior
Prosthodontics Professor, Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil.
Altair Antoninha
AA
Del Bel Cury
Prosthodontics Professor, Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas, Piracicaba, São Paulo, Brazil.
Guilherme Elias
GE
Pessanha Henriques
D001696:Biomechanical Phenomena; D001732:Bite Force; D017076:Computer-Aided Design; D003442:Crowns; D059605:Dental Implant-Abutment Design; D019250:Dental Implants, Single-Tooth; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D019094:Dental Prosthesis, Implant-Supported; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008422:Materials Testing; D017711:Nonlinear Dynamics; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
D003764:Dental Materials; D019279:Resin Cements; C493120:lithia disilicate; D003776:Dental Porcelain; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide