Differential expression of immunologic proteins in gingiva after socket preservation in mini pigs

Abstract

During healing following tooth extraction, inflammation and the immune response within the extraction socket are related to bone resorption. Objective: We sought to identify how the alloplastic material used for socket preservation affects the immune responses and osteoclastic activity within extraction sockets.Material and Methods : Using a porcine model, we extracted teeth and grafted biphasic calcium phosphate into the extraction sockets. We then performed a peptide analysis with samples of gingival tissue from adjacent to the sockets and compared the extraction only (EO) and extraction with socket preservation (SP) groups. We also used real-time polymerase chain reaction (PCR) to evaluate the expression level of immunoglobulins, chemokines and other factors related to osteoclastogenesis. Differences between the groups were analyzed for statistical significance using paired t tests.Results : Levels of IgM, IgG and IGL expression were higher in the EO group than in the SP group 1 week post-extraction, as were the levels of CCL3, CCL5, CXCL2, IFN-γ and TNF-α expression (p<0.05). In addition, receptor activator of nuclear factor kappa-B ligand (RANKL) was also significantly upregulated in the EO group (p<0.05), as were IL-1β, IL-6 and IL-8 (p<0.05).Conclusions : These results suggest that the beneficial effect of socket preservation can be explained by suppression of immune responses and inflammation.

Standardized Rat Model Testing Effects of Inflammation and Grafting on Extraction Healing

“…There was negative correlation between infiltrate density and palatal height in untreated specimens at day 28, and between degree of inflammation and BSD in the BMM group at day 28, suggesting that inflammation late in the healing cycle is harmful to bone quality. Inflammation adjacent to extraction sockets has been associated with markers of bone resorption, whereas socket preservation has been associated with decreased markers of inflammation and bone resorption 27 . In assessing the role of PGE2, a previous study by Lee et al 9 showed that higher levels of PGE2 in the first week of healing enhanced bone growth.…”

Environment and bone regeneration: how biomaterials, host mediators and even bacterial products can boost bone cells towards better clinical outcomes.

“…Interestingly, usually the presence of microbial agents is associated with an exacerbated host response, and consequently with impaired wound healing bone regeneration in vivo , such as during alveolitis 14 , 16 . In accordance, Jung, et al 11 (2015) demonstrate in this issue that the extension of the inflammatory and immunological response seems to be key in the regenerative process, since exacerbated host response results in a less favorable clinical outcome in the experimental model. Indeed, different patterns of host immune inflammatory mediators have been described to be associated with wound healing in active and inactive osteolytic lesions, contributing to the determination of lesions activity via the modulation of healing mechanisms 8 , 12 .…”

“…In addition, alginate hydrogels have additional significant properties; such as the potential as drug delivery vehicles, and indeed, the sustained delivery of BMP-2 was demonstrated to improve the material properties in vivo , increasing the local activity of bone formation marker alkaline phosphatase. Taken together, the studies by Jung, et al 11 (2015) and Li, et al 13 (2015) demonstrate that environmental conditions that support cell migration and differentiation towards osteoblastic phenotype can be associated with desirable clinical response, and a moderate and transitory expression of host inflammatory immunological mediators seems to play a constructive role in the regenerative process 2 , 10 .…”

“…Albiero, et al 1 (2015) demonstrate that periodontal ligament mesenchymal stem cells (PDLMSCs) cultures can sense microbial products (i.e. LPS), probably due to the significant expression of TLR4 and respond with the production of inflammatory molecules (interestingly, the same set of molecules analyzed by Jung, et al 11 (2015). The authors also demonstrate that under optimal osteogenic cell culture conditions, the microbial antigen and the associated cellular response resulted in the increase of mineralized matrix deposition and higher RUNX2 and ALP mRNA levels by CD105+ cells when compared to the control group.…”

“…Starting from the study by Jung, et al 11 (2015), the authors demonstrate that the socket preservation mediated by a biomaterial composed of 60% hydroxyapatite and 40% beta-tricalcium phosphate involves the modulation of host response at the socket. The authors demonstrate that a moderated host response is associated with a favorable biomaterial grafting outcome, involving host inflammatory and immunological factors, such as chemokines and cytokines.…”