ukubora   9  class 9
singular: uku-
  
1. decay, 2. something rotten (from kubora)
 ukubora : Prefixless Present 2. pers. sing. with 1.class 2.pers. sg. object of:
kubora (-boze)     v    to rot, spoil (vi)
caries    ukubungwa, ukubora kw'amenyo
En-En dictionary 
gangrene    ukubora kw'igikomere
En-En dictionary 
tooth decay   ukubungwa, ukubora kw'amenyo
En-En dictionary