The use of dental floss is appropriate to clean the interdental gums that completely fill the spaces between the teeth. It doesn't cause damage to the gum if introduced from 2 - 3 up to 5mm beyond the top of the papilla.
Cut approximately 40 or 50 cm of floss and coil most of it around the middle finger of one of your hands. Coil the rest in the opposite hand, this finger can be gathering the dental floss as it is used.
Hold firmly the tape or dental floss with the thumb and the index, allowing a distance of 2 or 3 cm between the fingers of each hand and with a soft saw-like movement insert it between the teeth against the tooth surface to clean it.
When the tape or dental floss reaches the edge of the gums, bend it in as a C against one of the teeth and slide it softly into the space between the gum and the tooth until you notice resistance.
Repeat this procedure with the rest of the teeth without leaving any space to clean.
For an easy use of the tape or dental floss you can use an applicator.