Dental Education Lecture: Brush & Floss
In previous lectures, we talk about brushing and flossing separately. In this lecture, we are going to discuss them together to let you understand why we need to do both. Fig.1 shows two upper front teeth and inflamed gums (red), which is due to accumulation of plaque and tartar (yellow) at tooth-gum junction. The distribution of plaque can be divided into two areas: 1 and 2. Plaque in area 1 is most efficiently removed by brushing at 45 degrees aiming at tooth-gum junction, whereas plaque in area 2 is best removed by flossing in a manner shown in two double-arrows in Fig.2. Two black dots represents floss, which should be placed in a narrow space between tooth and gums. We call the latter gingival sulcus. In fact the gingival sulcus is located at tooth-gum junction.
If you do not practice good personal oral hygiene as introduced here for a long time, there is abundant of plaque. Plaque is calcified by calcium from our saliva and changes into tartar, which is difficult to remove by yourself. Furthermore, plaque and tartar cause severe gum inflammation. Gums bleed easily when you brush. It will discourage you to develop good habit of oral hygiene. Therefore it is necessary first to seek dental cleaning to remove these tenacious plaque and tartar (Fig.3). Fig.3 is a cross section through one of two teeth shown in Fig.2. With irritants' removal, your gum tissue returns to normal condition, pink in color (Fig.4) and does not easily bleed. Then it is your turn to practice good oral hygiene to keep plaque and tartar in bay.
Arrowhead in Fig.4 points to buccal (next to our cheek) gingival sulcus, where plaque is most easily deposited. Toothbrush bristles should be aimed at the sulcus (Fig.5) to remove plaque that is just formed. Plaque forms around the clock (constantly). There is another gingival sulcus on the other side of our tooth (lingual, next to tongue, arrowhead in Fig.5). We should also pay attention to that area at brushing. If you do not brush these two most critical areas (instead brushing as shown in Fig.6) for a while, new plaque and tartar re-form near gingival sulci (sulcuses) (yellow) and cause gum swelling and redness again on both sides (Fig.6).
Xin Wei, DDS, PhD, MS 1st edition 01/19/2009, last revision 03/20/2010