He performed a dental crown procedure on Dexter Morgan.
In the dentist's chair, Dexter Morgan receives a shot of Novocaine to numb his mouth. The dentist asks Dexter about his summer. Dexter recounts in an ambiguous way that he went to a carnival (flashback of the carnival) and won a prize (flashback to Dexter injecting a man with M99, then collecting a bloodslide). The dentist hopes that Dexter stayed away from the sweet stuff. Dexter admits that he sometimes indulges (flashback to Dexter killing the man with a cleaver). Dexter states that he had met new people (flashback to Dexter adding a trophy to his new bloodslide box).
The dentist informs Dexter that the temporary crown may cause some blood. Keeping a straight-face, Dexter responds,”Not a problem. ”When the dentist asks Dexter if he still has his boat, Dexter answers, “You bet. It’s the only place I can let everything go” (referring to where he dumps his victims).
Later, when fighting with Oscar Prado, Dexter loses his crown. The next day, he is able to find it at the crime scene.