Subgingival microbial profiles and periodontal diseases in an isolated population from Brazil

Author(s)

Priscila Corraini

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia (FO/SDO)
• Defense date: 2012-02-29

Examining board members

Francisco Emilio Pustiglioni; Ana Paula Vieira Colombo; José Roberto Cortelli; Fernando de Oliveira Costa; Cristiano Susin

• Advisor: Francisco Emilio Pustiglioni

Abstract

AIMS: To investigate the prevalence and describe the subgingival microbial profiles of selected periodontal pathogens in the subgingival biofilm; and assess their role as possible diagnostic markers or risk indicators for destructive periodontal diseases in a periodontally untreated and isolated population from Brazil. MATERIAL AND METHODS: The target population consisted of all subjects aged 12 years (n=264) in an isolated Brazilian population. A full-mouth clinical examination was conducted, and pooled subgingival plaque samples were obtained from four sites per subject. PCR analyses were performed to identify the following microorganisms: A. actinomycetemcomitans, P. gingivalis, T. forsythia, P. intermedia and C. rectus, as well as the A. actinomycetemcomitans serotype distribution and JP2 clone detection. RESULTS: A. actinomycetemcomitans was detected in 25% of the subjects, whereas P. gingivalis, T. forsythia, P.intermedia and C. rectus were detected in 64%, 59%, 38% and 90% of the subjects, respectively. From the A. actinomycetemcomitans positive isolates (n=42), 18 (42%) were serotype a, 2 (5%) b, 19 (46%) c, 1 (2%) e, and 4 (10%) were non-serotypeable. None of the strains belonged to the JP2 clone. Two specific subgingival microbial profiles were identified: (1) In one, only C. rectus could or not be present (n = 31), while in the other, (2) Co-occurrence of T. forsythia and P. gingivalis was observed (n = 77). Profile 1 showed very low sensitivity values, and profile 2 showed varying sensitivity values for the identification of the various periodontal states, and considerably low to moderate specificity values. The following subgingival profiles were significantly associated with the prevalence of periodontal attachment loss (CAL) and probing depth (PD) in the final multiple logistic regression models adjusted for demographic, biological and behavioral variables: T. forsythia (PD and CAL 5 mm and 7 mm), P. gingivalis (CAL 7 mm) and the profile 2 (PD 5 mm and CAL 7 mm). CONCLUSIONS: The five studied periodontal microorganisms were prevalent in this isolated population. The A. actinomycetemcomitans positive subjects consisted predominantly of a and c serotypes. Two specific microbial profiles could be identified in this isolated population. They did not result in significant superior diagnostic accuracy when compared totraditional clinical markers. Subgingival microbial profiles presenting T. forsythia as risk indicator were significantly associated with increased PD and CAL in this isolated population. (AU)