2023, de Wild, Michael, Zimmermann, Simon, Klein, Karina, Steffen, Thomas, Schlottig, Falko, Hasler, Carol, Rechenberg, Brigitte von

This study was designed as proof of principle and safety test of the novel technique, the Immediate Stabilization System (ISS). The technique is designed to immediately stabilize polymer-augmented pedicle screws (PAS) in deficient bone and avoid complications of loosening pedicle screws at the bone-screw interface, especially in osteoporotic patients. A polymer sleeve was designed as augmentation to improve screw anchorage after drilling the screw hole. By applying ultrasonic energy, the polymeric tube was molded into the pores of the host bone forming a strong and uniform bond with the adjacent bone. The original screw was then implanted into the denser bony environment leading to an enhanced immediate stability. The ISS-treated implants were compared to conventionally placed pedicle screws in ex-vivo cadaver bones (2 sheep spines, n = 6 implants per spine, total 12 screws) and in-vivo in a spinal sheep model (Swiss alpine sheep, n = 5, 4 implants per animal, total 20 screws). The primary stability of ISS-treated pedicle screws was increased in ex-vivo bone (+24% insertion torque (IT)) and in-vivo (+32.9% IT) in sheep spine. Removal torque (RT) was lower in the in PAS tested for 8 weeks in-vivo. The ISS technology demonstrated improved anchorage of pedicle screws in ex-vivo cadaver bones as well as in-vivo studies in sheep spine.

2016-02-22, Stübinger, Stefan, Bucher, Ramon, Kronen, Peter, Schlottig, Falko, von Rechenberg, Brigitte

Aim: The ligature-induced defect model still remains the model of first choice to experimentally investigate the cause, effect and treatment approaches of periimplantitis. It was the aim of the present in-vivo trail to revisit the ligature-induced peri-implantitis minipig model regarding its current scientific value and ethical justification in implant research. Materials and methods: Six minipigs were used for the analysis of peri-implant hard and soft tissue structures. Animals were randomly allocated to an experimental silk ligature-induced peri-implantitis group (n=4 animals) and a reference healthy group (n=2 animals). After six weeks mean pocket depths (PD) and bleeding on probing (BOP) measurements were performed just before animals were sacrificed. Results: Overall, ligature-induced peri-implantitis provoked a local inflammation around the experimental implants. Additionally, a loss of crestal bone surrounding the implants could be detected. Mean pocket depths (PD) were 2.2 ± 1.1 mm for healthy animals and 5.4 ± 1.9 mm for peri-implantitis sites. Healthy sites showed a BOP of 60%, whereas peri-implantitis sites disclosed a BOP of 90% within 10 s after probing. Conclusion: Clinical, radiological and histological findings of the present animal experiment supported the overall applicability of the ligature-induced periimplantitis minipig model. A rapid breakdown of peri-implant hard tissues could be detected mainly on the buccal side.

2017-08, Schlottig, Falko

Our ability of screening broad communities for clinically asymptomatic diseases critically drives population health. Sensory chewing gums are presented targeting the tongue as 24/7 detector allowing diagnosis by “anyone, anywhere, anytime”. The chewing gum contains peptide sensors consisting of a protease cleavable linker in between a bitter substance and a microparticle. Matrix metalloproteinases in the oral cavity, as upregulated in peri-implant disease, specifically target the protease cleavable linker while chewing the gum, thereby generating bitterness for detection by the tongue. The peptide sensors prove significant success in discriminating saliva collected from patients with peri-implant disease versus clinically asymptomatic volunteers. Superior outcome is demonstrated over commercially available protease-based tests in saliva. “Anyone, anywhere, anytime” diagnostics are within reach for oral inflammation. Expanding this platform technology to other diseases in the future features this diagnostic as a massive screening tool potentially maximizing impact on population health.

2016-02-17, Burkhardt, Melanie, Waser, Jasmin, Milleret, Vincent, Gerber, Isabel, Emmert, Maximilian, Foolen, Jasper, Hoerstrup, Simon, Schlottig, Falko, Vogel, Viola

Low correlations of cell culture data with clinical outcomes pose major medical challenges with costly consequences. While the majority of biomaterials are tested using in vitro cell monocultures, the importance of synergistic interactions between different cell types on paracrine signalling has recently been highlighted. In this proof-of-concept study, we asked whether the first contact of surfaces with whole human blood could steer the tissue healing response. This hypothesis was tested using alkali-treatment of rough titanium (Ti) surfaces since they have clinically been shown to improve early implant integration and stability, yet blood-free in vitro cell cultures poorly correlated with in vivo tissue healing. We show that alkali-treatment, compared to native Ti surfaces, increased blood clot thickness, including platelet adhesion. Strikingly, blood clots with entrapped blood cells in synergistic interactions with fibroblasts, but not fibroblasts alone, upregulated the secretion of major factors associated with fast healing. This includes matrix metalloproteinases (MMPs) to break down extracellular matrix and the growth factor VEGF, known for its angiogenic potential. Consequently, in vitro test platforms, which consider whole blood-implant interactions, might be superior in predicting wound healing in response to biomaterial properties.

2016-02-23, Schmoelz, Werner, Mayr, Raul, Schlottig, Falko, Ivanovic, Nikola, Hörmann, Romed, Goldhahn, Jörg

Background: Screw anchorage in osteoporotic bone is still limited and makes treatment of osteoporotic fractures challenging for surgeons. Conventional screws fail in poor bone quality due to loosening at the screw-bone interface. A new technology should help to improve this interface. In a novel constant amelioration process technique, a polymer sleeve is melted by ultrasound in the predrilled screw hole prior to screw insertion. The purpose of this study was to investigate in vitro the effect of the constant amelioration process platform technology on primary screw anchorage. Methods: Fresh frozen femoral heads (n=6) and vertebrae (n=6) were used to measure the maximum screw insertion torque of reference and constant amelioration process augmented screws. Specimens were cut in cranio-caudal direction, and the screws (reference and constant amelioration process) were implanted in predrilled holes in the trabecular structure on both sides of the cross section. This allowed the pairwise comparison of insertion torque for constant amelioration process and reference screws (femoral heads n=18, vertebrae n=12). Prior to screw insertion, a micro-CT scan was made to ensure comparable bone quality at the screw placement location. Findings: The mean insertion torque for the constant amelioration process augmented screws in both, the femoral heads (44.2Ncm, SD 14.7) and the vertebral bodies (13.5Ncm, SD 6.3) was significantly higher than for the reference screws of the femoral heads (31.7Ncm, SD 9.6, p<0.001) and the vertebral bodies (7.1Ncm, SD 4.5, p<0.001). Interpretation: The interconnection of the melted polymer sleeve with the surrounding trabecular bone in the constant amelioration process technique resulted in a higher screw insertion torque and can improve screw anchorage in osteoporotic trabecular bone.

2015, de Wild, Michael, Hoffmann, Waldemar, Schlottig, Falko, Schumacher, Ralf, Bormann, Therese, Martin, Ivan, Müller, Bert, Mürrle, Ulrich