This categorically confirms that this is a tooth, it has enamel surrounding a core of dentine, that's the easy bit. I don't immediately recognise this tooth but considering possibilities ranging from rodent cheek to deer incisors I think it may be a worn (of filed) horse canine. I am not certain but there are a number of images on google serach which support this idea.
This tooth is very small to be a Boar Tusk, I can see that it could be one of the incisors of a boar although the crucial crown of this tooth is worn away . When finding bones in close proximity to each other you need to consider various possibilities including, 1) they are all from the same individual animal, 2) there are a number of different animal remains brought together by a preditor (this could include a hunter), 3) for beach or river bank finds; has flowing water or tides brought different bones to the same place. etc. Only someone who knows the location and details of the find can decide which is the most likely.