My boyfriend has gingivitis and I discovered he has used my toothbrush. Can I get gingivitis or any other gum disease? Also, other than good oral hygiene, what can he do for his gum issues? Thank you.

Not probable! Sure, gingivitis and most bacterial issues are transmittable between species however one needs to susceptible. If you are flossing daily, brushing in a vibratory manner at the gum tooth interface, you probably don't have and are not susceptible to gum issues from your boyfriends tooth brush. Think about it...You are kissing the guy ; you're ok! Isn't that a more direct means of transmission! .
Yes and dental visit. Microbiology studies have shown that the bacteria and micro- organisms that cause gum disease can be passed from one person to another by kissing. So if you kiss you boyfriend, you will exchange germs. As far as improving oral health other than better oral hygiene, regular prevention visits to the dentists 2x yearly (minimum) are essential! Let your boyfriend know that clean teeth are sexy!
Possibly but... Gingivitis is an infection, so anything that can be done to avoid getting an infection is advised. Use your own toothbrush, and if in doubt, get to a dentist and have your teeth thoroughly cleaned and checked. I would swish some anti-bacterial rinses, like listerine, and use good home care.
Unlikely. There are reports of transmission of gum disease from one spouse to another through intimate contact, but you probably aren't at risk from sharing a tooth brush. See his dentist for his problem, you can't treat it yourself.
Yes. I very strongly advise against sharing toothbrushes (or floss) with someone who has periodontitis. This is because these tools can reach and hold the bacteria that causes gum disease. Periodontitis is not a contagious disease through casual contact. But still you should make every effort to protect your mouth from the bacteria that causes periodontal problems.
The. The answer to your first question is yes. The bacteria that can lead to gingivitis or other forms of gum disease can be spread from sharing a toothbrush. Since your earlier questions involved concerns that your boyfriend might possibly be a MRSA carrier — I recommend that you throw out the toothbrush that he shared and get a new one. Even if there was not this level of concern, it is usually recommended that you replace your toothbrush every 3 to 4 months or sooner if the bristles are worn down or sharp. I recommend that each of you have different colored tooth brushes (soft bristles are preferable) and that you tell him that your tooth brush is off — limits to him. You can always keep some spare tooth brushes in the original wrapping in the bathroom, so that if he needs one, he can grab for one of these instead of your brush. In response to your second question: if your boyfriend has not had a dental cleaning in the last six months, encourage him to do so. Good brushing technique and flossing between teeth is essential for healthy teeth and gums.
Yes. You can spread bacteria from one person to another. This has been shown in studies. Other than good oral hygiene, professional cleaning and monitoring are necessary.