Influence of Screw Surface Treatment on Retention of Implant-Supported Fixed Partial Dentures

Abstract

The aim of this study was to assess the effect of a diamond-like carbon (DLC) coating on the removal torque of prefabricated implant screws after cyclic loading. Four groups with two crowns supported by two implants (n = 5) were obtained according to splinted and nonsplinted prosthesis, using titanium or DLC screws (splinted crowns with titanium screw [STi], splinted crowns with DLC screw [SC], nonsplinted crowns and titanium screw [NSTi], and nonsplinted crowns and DLC screw [NSC]). The prosthetic screws were tightened at 32 Ncm and retightened, and the specimens were submitted to 106 mechanical cycles (4 Hz/98 N). After cyclic loading, loosening torque was evaluated, and the final measurements were performed. Data were analyzed by two-way analysis of variance and Tukey's test (α = .005). There was statistically significance in the interaction of screw × splinting (P = .003). For the group that used titanium screws, NSTi showed smaller removal torque compared with STi. It was concluded that the use of the DLC coating screws in nonsplinted prosthesis maintain the torque after cyclic loading.

Types of retention for implant-supported fixed prosthesis: a narrative literature review

“…A qualidade da estabilidade do parafuso do pilar se relaciona diretamente com a pré carga, que corresponde à carga inicial do parafuso 19 . Com o objetivo de tentar reduzir o afrouxamento dos parafusos nesse sistema retentivo, alguns fabricantes têm realizado tratamentos na superfície desses componentes para atuarem como lubrificantes a seco, sendo exemplos de materiais de revestimento o ouro, o nitreto e o carbono semelhante a diamante (DLC: diamond-like carbon) 19,20 . O tratamento da superfície do parafuso reduz o atrito, aumenta a fixação e proporciona um maior número de giros do parafuso em um determinado torque 20 .…”

Abutment screw loosening in implants: A literature review

“…[ 19 ] Yet another study concluded that the area should be dry during the insertion of the abutment,[ 20 ] and another recommends using a screw with a diamond-like coating reduces the occurrence of screw loosening. [ 21 ]…”

Biomechanical behavior of three different types of internal tapered connections after cyclic and static loading tests: experimental in vitro

“…The mechanical complications of external connections remain a concern in the implant community. To overcome the connection problems, a new concept of internal connection has been developed [2]. The internal connection has mechanical advantages, such as drastic reduction of screw fractures, distancing the occlusal forces deep into the implant, and protecting the screw from overload [3].…”