Checking array value and adding corresponding css class

Question

I am developing an odontogram and in the registration form which tooth or teeth will be made the treatment. These choices are recorded in a column and a flag 0 in another column relating that that dental treatment has not yet been performed. Taking for example:
column teeth | column flag
               13 0
          17,18 0 0
        11,15,21 1
If zero treatment is open, has not yet been performed and a class will be inserted for the tooth to be red, if 1, a green class will be inserted for that tooth, the treatment has been performed and if there is no tooth will be added gray class.

What I’m not getting is to relate each tooth to its flag and add the corresponding class. For each tooth on the front in the form will be called this function and will verify that that tooth passed as parameter is registered and will mark it with the corresponding color. I am able to find the tooth, but I am not able to understand a condition for it to add the class matches whether or not there is the tooth corresponding to its flag. The idPatient and Teeth variable are passed by parameter in the function.

`

 $query = $this->db2->select( 'treatment_teeth, treatment_flag' )->from( 'tbl_enchiridion_treatment' )

 ->where( 'treatment_id_patient', $idPatient )->get()->result();

 $store = '';

  foreach( $query as $v )
  {
    $store .= $v->treatment_teeth . ',';
  }

  $substr = substr( $store, 0 , -1 );       

  if( in_array( $teeth, explode( ",", $substr ) ) )
  {
    return 'odontogram-tooth-on-process';

  }else{

    return '';
  }

}`