In vivo acid etching effect on bacteria within caries-affected dentin

Area of Science:

• Dentistry
• Microbiology
• Biomaterials

Background:

• Minimally invasive caries removal aims to preserve tooth structure.
• Acid etching is used in adhesive dentistry to improve bond strength.
• The effect of acid etching on residual bacteria in caries lesions is not fully understood.

Purpose of the Study:

• To evaluate the in vivo effect of acid etching on cariogenic bacterial activity in dentin after selective caries removal.
• To compare bacterial counts and activity between acid-etched and non-etched groups post-restoration.

Main Methods:

• Twenty-eight carious teeth underwent selective caries removal.
• Teeth were randomly assigned to acid etch (E) or no etch (NE) treatment before adhesive restoration.
• Dentin biopsies were collected at baseline and 3 months for bacterial quantification and activity assessment using qPCR and RT-PCR.

Main Results:

• No significant differences in total bacterial number or activity were found between the E and NE groups.
• In the NE group, residual Streptococcus mutans counts decreased, but activity per cell increased significantly at 3 months.
• This increase in bacterial activity was not observed in the acid-etched (E) group.

Conclusions:

• Acid etching prior to adhesive restoration may have an inhibitory effect on the activity of residual cariogenic bacteria.
• While not statistically significant between groups, the findings suggest a potential benefit of acid etching in managing bacterial activity post-treatment.
• Further research is needed to confirm the direct or indirect inhibitory mechanisms of acid etching on cariogenic bacteria.