Paiva Magnus Sérgio Martins de, Oliveira Samila Neres de, Dias Jéssyca Viviane Andrade, Neto Cypriano Galvão da Trindade, Queiroz José Renato Cavalcante de, Oliveira Erika Almeida de, Júnior Amílcar Chagas Freitas
*Health School, Potiguar University-Laureate International Universitiess †Departament of Dentistry, Federal University of Rio Grande do Norte ‡Privacy Practice, Natal §Departament of Dentistry, Federal University of Rio Grande do Norte, Natal, Brazil.
J Craniofac Surg. 2017 Mar;28(2):e145-e146. doi: 10.1097/SCS.0000000000003330.
Rehabilitation with implant-supported prostheses has reached high success rates. However, mechanical failures are still reported, mainly in retention screws of abutments in single implant-supported crowns; which is designed to be the weakest structure and the first component to fail under overloading. In this sense, the aim of this in vitro study was to evaluate the influence of different joint designs (square or hexagonal) on resistance to deformation of driver-retention screw assembly of 3 commercial brands (Neodent, Singular, and Sin). A total of 42 retention screws from 3 commercial brands were used. The samples were divided into 2 joint groups, square (SQU) and hexagonal (HEX), and separated by commercial brands. Several components (implants and abutments) with standard platform (4.1 mm in diameter) were used. The resistance to deformation of the driver-retention screw assembly was measured using an accurate digital torque wrench for all commercial brands (Neodent [NEO], Singular [SGL], and Sin [SIN]) and joint designs (square or hexagonal). It was found no statistically significant difference (P <0.05) among the brands evaluated. On the other hand, square screws showed higher resistance to torsion than hexagonal screws; regardless the commercial brand.
