Aspergillus fumigatus biofilm formation on different bone substitutes used in maxillary sinus augmentation: an in vitro analysis

Abstract

Background Fungus ball (FB) typically affects healthy adults, and Aspergillus fumigatus is the most frequent etiologic agent: iatrogenic factors represent an important issue in FB pathogenesis. Moreover, a recent study suggested a significant association between the use of anorganic bovine bone as sinus grafting material and subsequent development of FB. The aim of the present investigation is to evaluate in vitro eventual differences in the ability of Aspergillus fumigatus to colonize different bone grafting materials and grow on them as biofilm. Findings Five different bone substitutes (demineralized bone matrix, anorganic bovine bone, ß-tricalcium phosphate, synthetic nano-hydroxyapatite, and synthetic hydroxyapatite), commonly used in sinus floor augmentation procedures, were inoculated with conidia suspensions of A. fumigatus and incubated at 37 °C for 4 and 8 h, in standardized conditions. Biofilm bound to the different materials underwent quantitative and qualitative analysis by confocal and scanning electron microscopy. A. fumigatus proved to be able to adhere and form biofilm on all the tested bone substitutes. The surface plot representation of the samples displayed some differences in the density of the superficial layer, due to the physical characteristics of the biomaterials. Nevertheless, Kruskal–Wallis test showed no significant differences in biomass amount among the five bone substitutes ( p = 0.236 and p = 0.55 after 4 and 8 h adhesion, respectively). Conclusions All the bone substitutes normally used in sinus floor augmentation represent a favorable substrate for fungal growth, due to their physical and chemical characteristics. During sinus floor elevation procedures, Schneiderian membrane integrity should be maintained in order to avoid the exposure of the grafting material at the respiratory environment, with potential risks of fungal colonization.

Diagnostic reliability and accuracy of the hydraulic contrast lift protocol in the radiographic detection of sinus lift and perforation: ex vivo randomized split-mouth study in an ovine model

“…TSFE could lead to rare complications, more specifically a case report described the occurrence of conjunctival chemosis [ 26 ] and another described a brain abscess as a result of the procedure [ 27 ]. Intrusion of graft material into the sinus lumen is associated with the formation of fungus ball (aspergilloma) within the maxillary sinus that require additional surgical intervention for removal [ 28 , 29 ].…”

Biomimetic Nanopillar Silicon Surfaces Rupture Fungal Spores

“…Furthermore, Aspergillus spp. are known to grow and proliferate on various bone substitutes [ 20 ], implicating the susceptibility of dental biomaterials to contamination by environmental filamentous fungi that are also opportunistic pathogens. In addition, the presence of zinc oxide endodontic sealers into the maxillary sinus are known to increase the risk of filamentous fungal infection in immunocompromised individuals [ 21 ].…”