Evaluation of active and arrested carious dentin using a pH-imaging microscope and an X-ray analytical microscope

Area of Science:

• Dental Research
• Biomaterials Science
• Microscopy Techniques

Background:

• Dental caries involves demineralization and remineralization processes.
• Understanding the acid-base characteristics of carious lesions is crucial for diagnosis and treatment.
• Current methods for assessing lesion activity and mineral content have limitations.

Purpose of the Study:

• To evaluate the efficacy of a pH-imaging microscope in characterizing active and arrested carious dentinal lesions.
• To compare pH changes with mineral loss in carious lesions using correlative microscopy.
• To investigate the relationship between pH values and mineral content in different stages of dental caries.

Main Methods:

• Extracted human molars with active and arrested carious lesions were analyzed.
• A pH-imaging microscope was employed to measure surface pH changes on dentin.
• An x-ray analytical microscope was used to quantify mineral loss in the same lesions.

Main Results:

• Intact dentin had a pH of 7.0, active lesions averaged 5.8, and arrested lesions averaged 6.6.
• Active lesions exhibited significantly higher mineral loss (4.92x intact dentin) than arrested lesions (2.19x intact dentin).
• A strong negative correlation was found between pH and mineral loss in active lesions (r=-0.8024).

Conclusions:

• pH-imaging microscopy effectively differentiates between active and arrested carious lesions.
• Reduced pH and increased mineral loss are indicative of active dental caries progression.
• Correlative analysis of pH and mineral content provides valuable insights into carious lesion dynamics.