A diastema is a space between front teeth.  Diastemas are closed by orthodontics Braces or Composite restoration.  A highly successful technique is addition of composite when space is less.  A space which is too large and closed with composite results in teeth that are esthetically too wide in such condition orthodontics Braces is recommended for short term to close space,  Sometime it require combination of both.
Space closure requires placement of composite two adjacent teeth.  Placement of composite onto one tooth can be done it proper tooth dimensions allow it. Anesthetic is not required unless dentin or root structure is involved.  Tooth surfaces are prepare creating a rough surface for improved bond strength.    Blending composite color to tooth color is achieved by proper composite selection, placement and preparation design.