Evaluation of the effects of smoking on the clinical and histological characteristics and levels of growth factors in autologous fibrin membranes.

Objectives: Considering the increase in regenerative dental treatments, autologous fibrin membranes (ARMs) have been widely used in tissue engineering, favoring the regeneration of hard and soft tissues, accelerating angiogenesis and promoting cell differentiation and migration. This study proposed evaluate the differences in clinical characteristics and levels of the growth factors BMP-2, IGF, PDGF and VEGF between smokers and nonsmokers were evaluated according to the guidelines of the US Preventive Service Task Force (USPSTF).

Materials and methods: Fourteen smokers and 14 nonsmokers were selected. After processing, the samples were allowed to rest in tubes for 5 min for the organization of the matrix and completion of the fibrin clot. Only the yellow portion and the buffy coat were removed and stored. Four clots were obtained from each donor and used to quantify the release of the growth factors BMP2, PDGF, IGF and VEGF. In addition, histological analyses were performed, and clinical characteristics were evaluated.

Results: The data were tabulated and subjected to statistical analysis with a significance level of 5%. In both groups, the membranes remained intact throughout the analysis period, indicating similar structural behavior. Histological evaluation of the membranes obtained from the participants revealed the presence of more homogeneous fibrin membranes in the nonsmoker group and many leukocytes bordering the entire fibrin clot. In the smoker group, heterogeneous fibrin clots, sometimes malformed, and fewer leukocytes in the region of the buffy coat and bordering the entire fibrin were observed.

Conclusions: Smokers had significantly lower levels of VEGF, PDGF and BMP-2 (pg/ml in 1 µg total protein) than smokers did (p < 0.05), and there was no significant difference in IGF levels (p > 0.05) between the groups. There was also no statistically significant difference in membrane size between smokers and nonsmokers (mm, p > 0.05).

Clinical relevance: Smoking may interfere with the formation of the fibrin mesh and consequently affects the quality and regenerative capacity in in smoking patients.