Discussion
In this randomised trial, we found that silicone gel and onion extract gel had similar effects in making surgical scars less distinct. We also found that these two scar emollients had excellent or good compliances, with no obvious side effects during application to surgical wounds. To the best of our knowledge, this is the first study to compare the effects of silicone gel and onion extract gel on surgical scars. The action mechanism of silicone gel is considered as the promotion of hydration of the skin surface (Chan et al. 2005). Davey et al. (Perkins et al. 1983; Quinn et al. 1985) reported that the relatively impermeable silicone material acts in the same way as the stratum corneum. Another mechanism was described by, McCauley et al. (McCauley et al. 1990), who reported the inhibitory effect on fibroblast growth in cultured human skin fibroblasts and cultured bottles coated with silicone gel. Currently, these two hypotheses are thought to be the main mechanisms of silicone gel's effect on scar formation. Silicone gel has demonstrated positive effects on hypertrophic scars and keloids in many previous studies (Sproat et al. 1992; Cruz-Korchin, 1996). The authors hypothesised that the positive effects of the silicone gel at the cellular level would translate to newly created surgical scars. Moreover, the positive effect of the silicone gel has been most frequently reported for the induction of good scar maturation among many adjunctive methods (Sproat et al. 1992; Cruz-Korchin, 1996; Chan et al. 2005).
