Sentence 1: Carlos had one bad tooth. 
 Sentence 3: Because he was so stubborn, he refused to go to the dentist 
 Sentence 4:  But when the pain became unbearable he had to go 
 Sentence 5:  The dentist removed the tooth and Carlos could eat normally again 
 Option 1: He went to the dentist right away. 
 Option 2: It hurt him every time he ate something.