Limitation of the antibiotic‐eluting bone graft substitute: An example of gentamycin‐impregnated calcium sulfate

Abstract

Patients with inadequate volume of alveolar processes or bone defects commonly require graft substitutes in oral, maxillofacial or orthopedic surgery. Ridge augmentation and reconstruction of facial bony defects with bone graft materials achieve better outcomes in functional and aesthetic rehabilitation. The injectable calcium sulfate filler is used widely in intra-operative applications. Calcium sulfate bone filler has been shown to upregulate bone formation-related mRNA genes in vitro and improve osseointegration in vivo. In addition, the bone graft substitute can be used as a drug delivery system for antibiotics to treat or prevent infections based on the clinical experiences. However, the influences of antibiotics addition on the calcium sulfate are not fully understood. In this study, calcium sulfate impregnated with gentamycin in different weight ratios was characterized. The results showed that gentamycin prolonged the hydration process and extended initial/final setting times of calcium sulfate. The addition of gentamycin slowed the conversion from calcium sulfate hemihydrate to dihydrate and changed the crystalline phase and microstructure. Higher amounts of gentamycin added resulted in faster degradation and lower mechanical strength of calcium sulfate. This study reveals that the extended setting time, decreased compressive strength, and the accelerated degradation of the gentamycin-impregnated calcium sulfate bone graft substitutes should be considered during intra-operative applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 80-87, 2018.

Cathelicidin LL37 Promotes Osteogenic Differentiation in vitro and Bone Regeneration in vivo

“…Presoaking implants with an antibiotic solution are recommended before the placement of implant materials. However, the antibiotic effect of presoaking implants is time-limited and some antibiotics have been reported to negatively impact bone regeneration ( Wu et al, 2018 ). To avoid infection and also promote osteogenesis, there is a critical need for the development of novel engineered bone tissue materials for orbital defect reconstruction.…”

Alveolar Preservation with Albumin and Gentamycin-Coated Allograft after Third Molar Tooth Removal: A Randomized Clinical Trial

“…One would hypothesize that adding an extra layer of prevention would not do any harm so even if this is not specifically indicated it may be used as a cautionary measure [10]. One of the key observations of the current study is that this reasoning is downright wrong, and not just because of the often cited issue of promoting antibiotic resistance, but also that gentamycin interferes with bone remodelling and thus hinders the very aim of the surgery [11]. However, its use is not supported by conclusive evidence and clear surgical protocol in the literature.…”

“…One possible explanation is that the gentamycin might have a deceleration effect on bone remodeling in the present study. When calcium sulfate is used as a carrier for gentamycin, it prolonged the hydration of calcium sulfate and adhered to the whole crystal-forming process [11]. In vivo experiments proved that gentamycin or vancomycin-coated human bone graft application in a bone defect model caused decreased healing rate and less mineralization [37,38].…”

Functionalization of Synthetic Bone Substitutes

“…It is known that gentamycin decelerates the hydration process of calcium sulfate. High amounts of gentamycin result in faster degradation and lower mechanical strength of calcium sulfate [ 92 ]. In contrast, doxycyclin doped deproteinized cancellous bovine bone showed statistically increased mineralized new bone formation in comparison to cancellous bovine bone alone.…”