TNF and periodontitis: Table 1 shows the amount of TNF-α expression in male Wistar rats with periodontitis. In the treatment group with initial SRP therapy combined with VCO gel and the negative control group with SRP treatment alone, a significant increase was seen in the amount of TNF-α expression (p < 0.05) between day 7 and day 14, while in the positive control group, the combination of SRP and metronidazole gel showed the amount of TNF-α expression on the 7th and 14th days was not significant (p > 0.05).