Last month, I attended a party at my doggie day care facility and won a lovely gift basket of doggie products, including a Triple Pet Toothbrush like this one (mine is yellow). The toothbrush I had been using for my Shih Tzu was the typical one with a small brush head on one end and a large one on the other. Even though I used the small end, my dog would fight me when I tried to open her mouth wider to let me get the inside of those back teeth.
With the Triple Pet, I can brush the inside of her teeth WHILE I'm brushing the outside, so there is not nearly the struggle with brushing that there was with the old brush. This is because the Triple Pet is like 3 toothbrushes in 1...a very small regular toothbrush with "wing" brushes on either side of it.
After applying doggie toothpaste to the brush, I used the tip of my index finger to smear the paste around on all parts of the brush. Then, I open my dog's mouth just enough to get the brush in and "frame" a row of her teeth with the 3-sided brush and start brushing. Since it is 3-sided and "frames" the teeth, it helps you know that you have the brush in the right place if the dog is moving around or busily trying to lap up the toothpaste (as mine usually is).
I've only used the brush a few times so far, so I can't speak to its longevity. I can see, with the way the "wings" are attached, that it may not hold up a long time, especially with a dog that is fighting havings its teeth brushed or who is chewing down on the brush a lot...especially a larger dog. Time will tell! For now, I am happy to not have to struggle so much to get the job done!
UPDATE 7/18/12: Wanted to report that we are at about the 4-month point with this toothbrush and it shows no signs of wear. Very happy about this! I brush my dog's teeth anywhere from once every other week to once or twice a week. I have a Shih Tzu and their eyes need to be cleaned regularly, so while I have her up on the counter to clean her eyes, I also brush her teeth.
UPDATE 11/12/12: We're now around the 8-month mark with this brush and it still shows little sign of wear. Granted, I have not been brushing Missy's teeth as regularly the past few months as I had earlier in the year, but it is still working just as well today as it did when I got it. Also, I find that I can get through teeth brushing faster and, since the dog really doesn't ENJOY tooth brushing, this is good for both of us.