In vitro effect of three-dimensional (3D) titanium mini-plate systems used for surgical treatment of condylar fractures on interleukin 1 (IL-1) and interleukin 6 (IL-6) concentration in THP-1 macrophages.

About 20 %-35 % of mandibular fractures occur in the condylar process, a complication frequently associated with craniofacial traumas. Compared to other craniofacial fractures, some controversy remains around the effectiveness of the various treatment methods. It has been suggested that condylar osteosynthesis using mini-plates - a technique widely used by maxillofacial surgeons - may activate a pro-inflammatory response which is mediated by interleukins, later involved in bone remodelling and tissue regeneration. This study aimed at examining the influence of three-dimensional (3D) titanium mini-plate systems and the dedicated screws used in the surgical treatment of condylar fractions on the concentrations of interleukin 1(IL-1) and interleukin 6 (IL-6) in macrophages obtained from THP-1 monocytes. The cells were cultured for 24 h and 48 h with the 3D titanium condylar plates and dedicated screws (Synthes, Martin, Medartis manufacturer). The concentrations of IL-1 and IL-6 were measured using the ELISA method. Incubation of macrophages with plates did not cause a significant increase in IL-1 (for: Synthes 0.89-0.86 pg/mg protein; Martin 1.10-0.80 pg/mg protein; Medartis 1.20-0.84 pg/mg protein) and IL-6 (for Synthes 16.00-14.00 pg/mg protein, Martin 13.0-10.0 pg/mg protein; Medartis 9.0-12.0 pg/mg protein) expression for any of the plates used, compared to THP-1 macrophages incubated for 48 h under control conditions. Neither three-dimensional titanium mini-plates nor dedicated screws caused any changes in IL-1 and IL-6 expression in THP-1 macrophages, which is an important observation for clinicians treating condylar fractures. It confirms that titanium plates can be a safe/neutral material for humans, especially considering their significant influence on the osteoclast functions and bone remodelling processes after implantation.