Dental Education Lecture: Local Antibiotic





When we do not pay attention to personal oral hygiene for quite a while, tartar and plaque begins to extend below the gum line.  We need deep cleaning.  Medically it is called scaling & root planing.

If tartar extends too deep below gum line or the more severe form of gum diseases (periodontitis) develops into an abscess, deep cleaning itself may be not enough.  We may need surgery or apply local antibiotics into the deep pocket to resolve the severe infection.  

One day a gentleman in his late thirties presented to my office with chief complaint of pain and swelling in the lower right jaw (Fig.1).  X-ray exam reveals a large piece of tartar in the root of the affected tooth (arrowhead, Fig.2).  There is typical bone loss just below the tartar (*).  We do deep cleaning under local anesthesia and inject a local antibiotic called Arestin into the pocket.  The discomfort disappears very quick.  One month later, the same area looks fairly normal (Fig.3).

Let me use illustrations in Fig.4 to explain why we combine deep cleaning and local antibiotic to treat this case.  Fig. A is an illustration of the box in Fig.2: yellow representing tartar and plaque, and gray area representing alveolar bone surrounding the offending tooth.  Compared to the one on your side, the alveolar bone on the left loses its height and width (as indicated by arrows).  Let us add the inflamed, reddish gums in Fig. B.  Since this case is severe with deep pocket, the smallest instrument (black in Fig. C) cannot get to the deepest portion of tartar.  When upper portion of tartar is removed (curved arrow, Fig. D), the lower portion remains (straight arrow).  Then we need to rinse the pocket several time and inject an antibiotic into the pocket (curved arrow Fig. E).  Arrowhead points to the bottom of the pocket.  Combination of deep cleaning and local usage of antibiotic is most likely going to resolve all of infection and help gums heal (Fig. F pink).  Healing gums reattaches to the root surface, reducing the depth of pocket.  Arrowhead points to the bottom of the pocket of healed gums.

Magnification of illustrations in Fig.4 may not be enough.  If you want to understand better, please keep read the following with higher magnification. Let me magnify the boxed area in D as shown on the lower left.  The magnified Fig. D shows that there is tartar/plaque left (straight arrow) after deep cleaning (curved arrow).  A large amount of irrigation with Chlorhexidine (curved arrow in Fig. E1) reduces concentration of remaining tartar/plaque (from dark yellow in Fig. D to light yellow in Fig. E1).  Placement of antibiotic (curved arrow in Fig. E2) further kills the remaining bacteria inside pocket.  The blue circles in Fig. E2 represent beads to which antibiotic is attached.  Upper and bottom arrows in Fig. E2 point to the upper and lower ends of pocket, respectively.  After mechanic and chemical cleansing, gums return to normal color (pink in Fig. F) and re-attach to root surface, reducing the depth of pocket.  Two straight arrows indicate upper and lower end of the pockets, whereas the curved arrow points to the opening of pocket.  The reduction of pocket makes it easy to clean locally.

Xin Wei, DDS, PhD, MS 1st edition 01/21/2009, last revision 03/20/2010