Wk. Leung et al., SUBGINGIVAL MICROBIOTA OF SHALLOW PERIODONTAL POCKETS IN INDIVIDUALS AFTER HEAD AND NECK IRRADIATION, Oral microbiology and immunology, 13(1), 1998, pp. 1-10
Citations number
48
Categorie Soggetti
Immunology,Microbiology,"Dentistry,Oral Surgery & Medicine
This study aimed at investigating the subgingival plaque microorganism
s of shallow pockets (less than or equal to 5 mm) in subjects who prev
iously received irradiation in the head and neck region for treatment
of nasopharyngeal carcinoma. Direct microscopy and anaerobic culture w
ere used. Subgingival paper point samples were taken from 6 tooth-site
s (one/sextant) per subject for direct microscopy (n=108). Another set
of paper points was taken from the deepest of the previously selected
sites (one per subject) with: group A) no bleeding on probing to the
sulcus depth (n=9) and group B) bleeding on probing to the sulcus dept
h (n=6) for microscopic and anaerobic culture study. Under the microsc
ope, the microflora was found to be a complex mixture comprising gram-
positive and gram-negative cocci, rods and filaments, fusiforms, curve
d rods and spirochetes. Low level of fungi were observed and mycelia w
ere occasionally detected. There was no significant variation in the p
laque bacterial morphotypes observable according to sites of isolation
and no significant difference between group A and group B in morphoty
pes of the different microflora. The predominant cultivable microflora
comprised several species of facultative and obligate anaerobic bacte
ria: Gemella, Peptostreptococcus, Staphylococus, Stomatococcus, Strept
ococcus, Actinomyces, Eubacterium, Lactobacillus, Propionibacterium, N
eisseria, Veillonella, Bacteroides, Campylobacter, Capnocytophaga, Fus
obacterium, Kingella, Porphyromonas and Prevotella species. There was
no difference between the two groups except the significantly higher p
roportion of Kingella dentrificans isolated from group B sites. Howeve
r, colonization of the gingival sulcus in these individuals by microbe
s that are normal flora of: skin (Peptostreptococcus prevotii and Prop
ionibacterium granulosum) and gut (Eubacterium aerofaciens, Fusobacter
ium mortiferum and Fusobacterium varium) was detected. These findings
appear to suggest that the major components of the subgingival microfl
ora of shallow sites in previously head- and neck-irradiated individua
ls are similar to that of gingivitis sites in the normal population al
though they may contain bacterial or fungal species uncommon in normal
subjects.