Does Cigarette Smoking Induce Changes in Biologic and Mechanical Properties of Platelet-Rich Fibrin Membranes?

Smoking has a profound effect on platelet morphology and activation and has also been shown to affect hemostasis, coagulation, and healing cascade. To date, no previous reports are available to assess the impact of cigarette smoke on leukocyte- and platelet-rich fibrin (L-PRF) and advanced platelet-rich fibrin (A-PRF) membranes. Therefore, this study aims to analyze the impact of cigarette smoking on the mechanical and biologic properties of L-PRF and A-PRF membranes. Sixty blood samples from both smokers (n = 34) and nonsmokers (n = 26) who were matched for age and other factors were collected and subjected to complete blood count and platelet indices (mean platelet volume, platelet distribution width, platelet large cell ratio, and plateletcrit). The L-PRF membrane (2,700 rpm; 12 minutes) and A-PRF membrane (1,500 rpm; 14 minutes) were prepared using a standard protocol. A total of 64 experimental L-PRF and A-PRF membranes from 16 individuals selected randomly from the two groups were subjected to tensile strength evaluation using a micro universal testing machine and growth factor release analysis (platelet-derived growth factor [PDGF-AB], vascular endothelial growth factor [VEGF], and bone morphogenic protein-2 [BMP-2]) using ELISA (enzyme-linked immune sorbent assay). Results were tabulated, and statistical analysis was done using Mann-Whitney, Kruskal-Wallis, and Spearman correlation tests. Tensile strengths of L-PRF and A-PRF did not show a statistical difference between groups (P = .47). BMP-2 was not detected in any of the groups. A high initial release of PDGF-AB and VEGF was noticed in A-PRF samples from smokers. Although statistically insignificant, cigarette smoking does affect platelet activation and influences the tensile strength of L-PRF membranes as well as growth factor release in A-PRF membranes in smokers.

Evaluation of gingival tissue samples for predicting the time of death using histological and biochemical tests.

Thanatochemistry also known as chemistry of death and is used to determine post mortem interval (PMI). It is arguably one of the critical steps in forensic investigation. Recent addition of analyzing biochemical changes along with the traditional methods have gained importance, as they help us to record very early changes in the tissue specimens. In this view, our study aimed to correlate both histological changes and enzymatic changes in gingival tissue samples at intervals of immediate, 1 h, 5 h, 24 h and 48 h after death. Histologic changes noted were loss of epithelial architecture, chromatin clumping, nuclear vacuolation, karryopyknosis, eosinophilia and wide intercellular junctions. Two enzymes which differentiate between the autolytic phase (acid phosphatase) and putrefactive phase (ammonia) of decomposition were evaluated using UV spectrometer. Results in our study demonstrated there were variations as in gradual increase in ammonia levels (1.13±0.24-26.6±2.09) and gradual decrease in acid phosphatase levels (5.61±0.67-1.25±0.53) at different time intervals till 48 h. The cellular changes in gingival tissue could also be related to time. The result of our study helps us to identify potential of enzymatic changes which when correlated with histological reports helps us to predict the time of death accurately. Replicating this experiment in various known taphonomic conditions and other enzymes could highlight the usefulness of gingival tissue samples in determining time of death.

Effect of Cigarette Smoking on Morphologic Characteristics of Two Different Platelet-Rich Fibrin Membranes: A Scanning Electron Microscopic Study.

PURPOSE: Platelet concentrates are used for regenerative periodontal and implant therapy. Up to now, no study has reported the influence of smoking on platelet-rich fibrin membranes. Hence, this cross-sectional in vitro study aimed to analyze the influence of cigarette smoking on platelet morphology and fiber characteristics of both leukocyte- and platelet-rich fibrin and advanced platelet-rich fibrin membranes. MATERIALS AND METHODS: Sixty blood samples from both smokers (n = 34) and nonsmokers (n = 26) based on power analysis were collected and subjected for complete blood count and platelet morphology indices (mean platelet volume, platelet distribution width, platelet-large cell ratio, and plateletcrit). Leukocyte- and platelet-rich fibrin membrane (2,700 revolutions per minute for 12 minutes) and advanced platelet-rich fibrin membrane (1,500 revolutions per minute for 14 minutes) were prepared using a standard protocol. Thirty-two platelet-rich fibrin membranes from 16 individuals were selected randomly from the two groups and were subjected to morphologic examination using a scanning electron microscope. RESULTS: Both of the groups were matched for age. Red cell counts and white cell counts showed no statistical difference between the groups. Platelet indices of smokers did show slightly higher values than the nonsmoking group. Scanning electron microscopic analysis showed variations in the fiber width and pattern among smokers in both the leukocyte- and platelet-rich fibrin and advanced platelet-rich fibrin membranes. Platelet cell morphology of the smoking group demonstrated spiky architecture, suggesting an active state, while in the nonsmoking group, the platelet cells were seen in clusters, suggesting a resting state. CONCLUSION: Scanning electron microscopic results show that long-term cigarette smoking does affect the thickness and arrangement of fiber architecture in both leukocyte- and platelet-rich fibrin and advanced platelet-rich fibrin membranes and also could have an impact on activation of platelets.