All rings are protected with ring armor, a protective layer which makes the ring water resistant.
Ring armor gives a rounded profile to the ring.
Wood rings are durable and can last a long time if taken care of properly. Each ring is sealed with a protective layer, I call it RING ARMOR, this gives a glossy shine look to the ring, and will round it a bit. 
Antler or wood rings will last for many years. They could last for generations depending on how it is worn and treated.

Broken and Cracked Rings: Due to the nature of using natural materials your ring should not be expected to withstand the same amount of abuse a metal ring would.

A wood or antler ring, just like a kitchen table, a hardwood floor or a well played guitar can get beaten up over time. Again, it depends on how you treat it and what you expose it to.

I use a waterproof protective layer that protects your ring from ultraviolet light and rapid changes in temperature. Other protections such as oils and waxes do not bring out the grains and colors in the wood the way my preferred finish does, nor is the ring as well protected.

Rings should not be exposed to hot water while showering and dishwashing. Nor to salty water as this can compromise the integrity of the seal and can make the ring vulnerable to break and to absorb water. If your ring fits tight due to swelling or improper sizing and is a struggle to remove this also can provoke breakage. Avoid lifting heavy objects while wearing your ring. Harsh chemicals can also damage your ring.