Predominant cultivable flora isolated from human root surface caries plaque

Area of Science:

• Oral microbiology
• Dental caries research
• Bacteriology

Background:

• Root surface caries is a common dental condition.
• Understanding the bacterial composition of root caries plaque is crucial for developing effective prevention and treatment strategies.

Purpose of the Study:

• To determine the bacterial composition of plaque from root surface caries lesions.
• To investigate the prevalence of key bacterial species, including Streptococcus mutans, Actinomyces viscosus, and Streptococcus sanguis, in root caries plaque.

Main Methods:

• Plaque samples were collected from root caries lesions.
• Continuous anaerobic culturing was employed for bacterial isolation.
• Morphological and physiological characterization of isolates was performed.
• Fluorescent antibody reagents were used for specific identification of Streptococcus mutans and Actinomyces viscosus.

Main Results:

• Plaque samples were categorized into two groups based on Streptococcus mutans presence.
• Group I plaques: Streptococcus mutans (30%) and Actinomyces viscosus (47%) were dominant; Streptococcus sanguis was low or absent.
• Group II plaques: Streptococcus mutans was absent; Streptococcus sanguis (48%) and Actinomyces viscosus (41%) were dominant.

Conclusions:

• Actinomyces viscosus is a predominant organism in root caries plaque, irrespective of Streptococcus mutans presence.
• Two distinct bacterial profiles exist in root caries plaque: one with S. mutans and low S. sanguis, and another without S. mutans but with high S. sanguis.
• These findings highlight the complex microbial ecology of root caries.