Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture the tweeter's mental state.
Tweet: Root canal therapy has had a bad reputation in the past... but new technology has allowed more comfortable procedures! #smile #dental
This tweet contains emotions: 
anticipation, joy, optimism, trust