Occlusal splints do take a few nights to get used too. If you are a gagger though it is really hard. Within a week you will notice a huge difference particularly if you suffer from head and neck tension pain. I have spent the best part of the last 7-8 years dealing with jaw issues and cosmetics. I'm not a specialist in this area but I am often refered a lot of the worse cases in my area. I'll try and condense some of what I have noticed over the years.
Tooth decay is only one area of concern. The other important area is the health of the bone around the teeth. a bioloigic width exists which is consistent throughout humans. Without going into too much detail it just means that gum will always sit 2mm above the underlying bone. It is so predictable that when you crown lengthen teeth you simple raise the gum, cut the bone 2mm below where you want to gum to sit and it will heal to that position. Always. It is the reason why I rarely use tooth brush abrasion as a cause for gum recession. You can scrape the gum back with a blade and as long as you don't damage the bone, it will grow back.
When I see gum recession I always look at the occlusion. More often (well, to be fair, almost always) those teeth that show recession are under heavy occlusal loads, usually when clenching and grinding. If you look in some ones mouth and see one molar on one side with receeding gums how the hell are they brushing in such a way that only one tooth is affected? You would expect every single tooth in a quadrant to experience the same force. As soon as I mention this to my patients you see an light go off and they realise the bullshit that they have been fobbed off all these years.
To be fair it is a little more complex than this but you should get the picture. If you are experiencing recession in your lower incisors I bet you any thing you had braces when you were a kid to correct a deep overjet or over bite. These cases are usually caused by pushing the lower teeth too far forward and punching the root through the thin plate of bone. This defect only has to be a few mm for the gum to start to head south. Once again if it is only one or two teeth afffected you couldn't possibly be that brutal with a tooth brush in a very small area, you would expect to see all the lower teeth involved.
The same thing is true about polishing away the enamel. Nylon tooth bristles are way softer than tooth enamel. Sometimes in a very acidic environment (bulimics, dehydrated mouths) you might have the potential to wear away a small amount but the hardness of enamel far exceeds plastic. More often you will see something like this blamed on tooth brush abrasion....
I find it difficult to believe that a person could scrub the two middle so hard that they wear away, yet some how avoid the two teeth next door. When I see this I would gaurantee that their bite is extremely heavy on the two worn teeth and the damage is caused by these teeth flexing under the load.
All this may seem a little confusing, it's hard to transfer 15 years of experience into a couple of paragraphs, particularly an area where I have a vested interest in.
TL,DR?
Brush your teeth with fluoride toothpaste, floss daily, regular 6 months hygiene visits to remove built up calculus deposits and an occlusal splint to wear at night to protect your teeth from gurning.