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Aciduric bacterial communities at three levels in dentin caries
Oral Health & Preventive Dentistry
|August 20, 2013
Summary
This study investigated acid-tolerant bacteria in dentin caries lesions. Findings show unique microbial communities at different lesion depths, highlighting the role of aciduric bacteria in caries progression.
Area of Science:
- Microbiology
- Dental Science
- Cariology
Background:
- Dentin caries involves a complex microbial ecosystem.
- Understanding acid-tolerant microbiota within caries lesions is limited.
- Microbial adaptation to pH and nutrient fluctuations is key in caries development.
Purpose of the Study:
- To investigate the acid-tolerant microflora at different levels of established dentin caries lesions.
- To utilize solid pH-selective media for microbial analysis.
- To characterize the microbial composition of caries lesions under varying pH conditions.
Main Methods:
- Samples from primary dentin caries lesions were collected at superficial, center, and floor levels from 10 patients.
- Samples were incubated on pH-neutral and pH-selective agars (pH 4.0, 4.5, 5.0, 5.5).
- Colony-forming units (cfu) were quantified, and isolates were characterized morphologically.
Main Results:
- Bacterial counts on blood agar (BA) ranged from 5.88 x 10³ to 5.85 x 10⁵ cfu.
- Recovered bacterial numbers decreased as agar pH decreased.
- Significantly fewer bacteria were found in clinically caries-free dentin compared to carious areas (P = 0.042).
Conclusions:
- Each dentin caries lesion exhibited a distinct microbial flora.
- Aciduric bacteria in various combinations can colonize, survive, and propagate dentin caries.
- pH-selective agars are effective for selecting acid-tolerant microorganisms, offering phenotypic insights not achievable with molecular methods.
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