title: Microleakage at Different Implant-Abutment Connections Under Unloaded and Loaded Conditions.
abstract: OBJECTIVE
  This study evaluated the microleakage at different implant-abutment (I-A) connections under unloaded and loaded conditions.
  
  
  METHODS
  Forty implants, specially designed with an opening at the apex, were grouped according to the I-A and screw device: external hexagon implants with titanium (EH) or EH diamond-like carbon screws fixing the abutment; internal hexagon implants with titanium screws (IH); and Morse taper implants with solid (MT) or MT passing screws (MTps) abutments. The implants were fixed in a 2-compartment device, and toluidine blue solution (1.0 mg/mL) was placed at the I-A interface (upper compartment). The lower compartment was filled with purified water. Four implants of each group were loaded (50 N, 1.2 Hz) and after 50,000, 100,000, 200,000, and 300,000 cycles, aliquots were collected from the lower compartment for absorbance reading. Data were analyzed using analysis of variance for repeated measurements and Tukey (α = 0.05).
  
  
  RESULTS
  Although microleakage increased over time in most of the groups, MTps group showed lower values when loaded (P < 0.05). The DLC on the EH screw did not prevent microleakage (P < 0.05).
  
  
  CONCLUSIONS
  It can be concluded that MT connection is more effective to prevent microleakage.
authors.affiliation: *Professor, Department of Prosthodontics, School of Dentistry, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil. †PhD Student, Department of Occlusion, Fixed Prostheses, and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil. ‡PhD Student, Department of Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. §Professor, Department of Prosthodontics, Health Sciences Center, Unigranrio University, Duque de Caxias, Rio de Janeiro, Brazil. ¶Titular Professor, Department of Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. ‖Associate Professor, Department of Occlusion, Fixed Prostheses, and Dental Materials, Dentistry School, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil.
authors.forename: João Paulo
authors.initials: JP
authors.lastname: da Silva-Neto
authors.forename: Marcel Santana
authors.initials: MS
authors.lastname: Prudente
authors.forename: Talita Souza
authors.initials: TS
authors.lastname: Dantas
authors.forename: Plinio Mendes
authors.initials: PM
authors.lastname: Senna
authors.forename: Ricardo Faria
authors.initials: RF
authors.lastname: Ribeiro
authors.forename: Flávio Domingues
authors.initials: FD
authors.lastname: das Neves
mesh_terms: D059605:Dental Implant-Abutment Design; D003763:Dental Leakage; D003799:Dental Stress Analysis; D018130:Diamond / Q000737:chemistry; D066298:In Vitro Techniques; D008422:Materials Testing; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry
chemical_list: D018130:Diamond; D014025:Titanium