Materials (Basel). 2019 Jun 25;12(12):2036. doi: 10.3390/ma12122036.
ABSTRACT
Peri-implantitis is an inflammatory disease affecting tissues surrounding dental implants. Although it represents a common complication of dental implant treatments, the underlying mechanisms have not yet been fully described. The aim of this study is to identify the role of titanium nanoparticles released form the implants on the chronic inflammation and bone lysis in the surrounding tissue. We analyzed the in vitro effect of titanium (Ti) particle exposure on mesenchymal stem cells (MSCs) and fibroblasts (FU), evaluating cell proliferation by MTT test and the generation of reactive oxygen species (ROS). Subsequently, in vivo analysis of peri-implant Ti particle distribution, histological, and molecular analyses were performed. Ti particles led to a time-dependent decrease in cell viability and increase in ROS production in both MSCs and FU. Tissue analyses revealed presence of oxidative stress, high extracellular and intracellular Ti levels and imbalanced bone turnover. High expression of ZFP467 and the presence of adipose-like tissue suggested dysregulation of the MSC population; alterations in vessel morphology were identified. The results suggest that Ti particles may induce the production of high ROS levels, recruiting abnormal quantity of neutrophils able to produce high level of metalloproteinase. This induces the degradation of collagen fibers. These events may influence MSC commitment, with an imbalance of bone regeneration.
Más información…
«In implant dentistry is it well accepted that a degradation process at the implant-abutment connection could be favored by several factors, such as the presence of a biofilm that, acting as lubricant, decreases the friction on the titanium (Ti) surfaces and causes micro-movements, which, in turn, can lead to wear. Moreover, biofilms can alter the pH, inducing wear particle formation as well. In vitro tests confirmed that micro-movements occurring at the implant-abutment connection can increase the wear of the inner surfaces of the connection and, subsequently, the release of metal ions and micro- and nanoparticles into the surrounding tissues [8–11]. In this view, the main question is if these degradation products released from dental implants could a ect peri-implant tissue, inducing pathologic bone resorption [8]. It is well accepted that metal nanoparticles are able to induce inflammatory e ects through their immunomodulatory capacity, mainly exerted at a macrophage level [8,12], by means of an increase in DNA damage, protein carbonylation, lipid peroxidation, oxidative stress and by a decrease in the activity of superoxide dismutase, total glutathione levels, and total antioxidant capacity catalase. Moreover, they induce an abnormal activation state of macrophages characterized by an excessive inflammation and a suppression of innate immune function [13,14]…»
PMID:31242601 | PMC:PMC6630980 | DOI:10.3390/ma12122036
