salt hurts wounds, yet saltwater rinses are recommended for cleaning oral wounds. why?


i’ve found information as to why saltwater rinses help heal oral wounds, and i’ve also found information as to why salt can be bad for other wounds, but i can’t figure out what’s different about oral wounds.

just had my wisdom teeth taken out and i’ve been wondering this

In: 7

It’s less about the location of the wound than the amount of salt. You can, in fact, “irrigate” or wash out other wounds with salt water if it’s clean.

Pure salt pulls water out of your cells, shrinking and possibly killing them. But depending on the concentration, salt water can do this more gently (good for removing fluid build-up from a wound) or not at all, if the salt concentration in the water matches the salt concentration in the tissue.

Most pathogenic bacteria that are likely to cause superficial wound infections, are gram-negative and do not have a thick outer cell wall. This makes them susceptible to being dehydrated by salty water. The higher salt concentration draws water out of bacterial cells causing them to become misshapen. This may either kill them outright or at least inactivate them and kill any in the process of dividing.

For the same reason, pickling foods with a salty, acidic vinegar solution kills most bacteria and fungi that cause decomposition and prevents the rest from growing at all.

Of course, normally this would also dehydrate, shrivel, and kill cells in your tissue as well.

However, typically the first thing that happens in wound healing is cells called fibroblasts produce a layer of scar tissue on the surface of the wound. Meanwhile other tissue cells fill themselves up with fibrous collagen and keratins, then undergo programmed cell death. This produces a thin, temporary barrier protects the living cells beneath the surface from various insults like toxic proteins produced by pathogenic bacteria, air pollutants like ozone, or from drying out. Meanwhile capillaries supply enough extra moisture to keep cells hydrated. The edges of the wound then grow together and then other cells dismantle and digest the dead cells.

You can basically think of this like an invading army of marauders trying to lay siege to a fortified town on top of a hill, say, in late fall.

The attacking army may have greatly superior numbers, better weapons, and better training and experience. However the city has strong defensive walls lots of shelter, and has stores of water and food for the winter. They also have a lot of quarried stones to repair damage to the wslls. Lets say a sudden freak winter storms blows in for several days. The attacking army only has thin tents, campfires, and is low on food, basically only that which they’re able to steal. While the city has plenty of fireplaces and sheltered alcoves in the walls, and stores of dried meat and fruits and grains, and cozy thatched cottages. The winter storm causes the local streams to freeze. So a lot of the invaders are likely to freeze during the nights, starve, or else simply abandon camp and turn mercenary.

Bacteria have few collective structural defenses and can only survive by their own recognizance for the most part. (Although a lot of pathogenic bacteria have interesting mechanisms whereby they can recognize nearby bacteria of the same species communicate with the group, and act collectively to frustrate the immune system. This is a field of active research.)