Yildiz, Ezgi DoganayArslan, HakanKoseoglu, SerhatArabaci, TanerYildiz, Dursun AnilSavran, Levent2020-06-252020-06-252019closedAccess0268-89211435-604Xhttps://doi.org/10.1007/s10103-018-2625-3https://hdl.handle.net/20.500.12587/7821Savran, Levent/0000-0001-8824-3207To investigate the effect of photobiomodulation (PBM) and placebo on total amount of substance P in gingival crevicular fluid (GCF) pre- and postoperatively. Twenty-six patients having tooth with symptomatic apical periodontitis were enrolled in this study. GCF was collected preoperatively. The patients were assigned into two groups (n=13), as follows: placebo and PBM. Sampling was repeated 7days after root canal treatment. Two independent samples T test was used for analyzing of the differences between preoperative and postoperative substance P levels in GCF (p=.05). The Pearson correlation analysis was used for determination of correlation among substance P levels and other variables. For placebo group, there is no significant difference between preoperative and postoperative total amounts of substance P level (p=0.553). For PBM group, postoperative total amount of substance P level was significantly higher than those of preoperative level (p=0.005). Within the limitation of the present study, PBM has immunomodulation effect linked to the modulation of the total amount of substance P in the gingival crevicular fluid. Thai Clinical Trials Registry: TCTR20161228002eninfo:eu-repo/semantics/closedAccessSubstance PPhotobiomodulationPostoperative painGingival crevicular fluidArticle34351752310.1007/s10103-018-2625-32-s2.0-8505283457230171442Q1WOS:000461371500011Q2