In-vitro development of a temporal abutment screw to protect osseointegration in immediate loaded implants.
OBJECTIVE
In this study, a temporal abutment fixation screw, designed to fracture in a controlled way upon application of an occlusal force sufficient to produce critical micromotion was developed. The purpose of the screw was to protect the osseointegration of immediate loaded single implants.


METHODS
Seven different screw prototypes were examined by fixing titanium abutments to 112 Mozo-Grau external hexagon implants (MG Osseous®; Mozo-Grau, S.A., Valladolid, Spain). Fracture strength was tested at 30° in two subgroups per screw: one under dynamic loading and the other without prior dynamic loading. Dynamic loading was performed in a single-axis chewing simulator using 150,000 load cycles at 50 N. After normal distribution of obtained data was verified by Kolmogorov-Smirnov test, fracture resistance between samples submitted and not submitted to dynamic loading was compared by the use of Student's t-test. Comparison of fracture resistance among different screw designs was performed by the use of one-way analysis of variance. Confidence interval was set at 95%.


RESULTS
Fractures occurred in all screws, allowing easy retrieval. Screw Prototypes 2, 5 and 6 failed during dynamic loading and exhibited statistically significant differences from the other prototypes.


CONCLUSIONS
Prototypes 2, 5 and 6 may offer a useful protective mechanism during occlusal overload in immediate loaded implants.
Department of Prosthodontics, School of Dentistry, Universitat Internacional de Catalunya, Barcelona, Spain.
Herminio
0000-0001-7135-8147
H
García-Roncero
Department of Oral and Maxillofacial Surgery, School of Dentistry, Universitat Internacional de Catalunya, Barcelona, Spain.
Jordi
0000-0003-4684-4770
J
Caballé-Serrano
Department of Prosthodontics, School of Dentistry, Universitat Internacional de Catalunya, Barcelona, Spain.
Jordi
0000-0002-4942-4774
J
Cano-Batalla
Department of Prosthodontics, School of Dentistry, Universitat Internacional de Catalunya, Barcelona, Spain.
Josep
0000-0001-9829-2651
J
Cabratosa-Termes
Department of Prosthodontics, School of Dentistry, Universitat Internacional de Catalunya, Barcelona, Spain.
Oscar
0000-0002-8210-4844
O
Figueras-Álvarez
Dental implant-abutment; Immediate dental implant loading; Single-tooth dental implant