scandir() returns an array already, why are you converting it to a string then back to an array? also your new array will be undefined because the delimiters are different.
This should be sufficient to iterate through the array results:
$dir = "/some/folder";
// Sort in ascending order
$array = scandir($dir);
foreach($array as $item)
{
$dbcon="INSERT INTO $DBTable(Column) VALUES('$item')";
/*
I AM ASSUMING THAT YOU UNDERSTAND THAT YOUR SQL QUERY IS NOT DOING ANYTHING YET since you haven't called mysqli_query();
Also - have you defined the connection??
*/
}
?>