BIOMARKERS OF BONE REMODELING AND INFLAMMATION IN CHRONIC PERIAPICAL LESIONS: A NARRATIVE REVIEW

Chronic periapical lesions are inflammatory conditions that cause ongoing destruction of the alveolar bone. While microbial infection is known to be the initial cause, the complex interplay between the types of microbes present, immune responses, factors affecting the whole body, and bone remodeling processes is not yet fully understood.

This narrative review summarizes current evidence on how bone metabolism changes in chronic periapical lesions. It also examines the roles of inflammatory mediators, osteoimmune pathways, systemic factors, and imaging techniques in understanding how the disease progresses and how well it can heal.

A narrative search was performed across electronic databases, including PubMed, Scopus, and Web of Science, for relevant studies. These studies investigated chronic periapical lesions, bone metabolism markers, inflammatory pathways, vitamin D levels, systemic factors, and imaging assessments. We analyzed evidence concerning biomarkers of bone formation and resorption, osteoclast activation, and bone remodeling mechanisms.

Current evidence shows that biofilms in root canals trigger the release of pro-inflammatory substances. This leads to higher levels of RANKL and lower levels of osteoprotegerin (OPG), which encourages the development of osteoclasts and the breakdown of bone matrix. Markers of bone resorption, such as CTX and TRACP5b, are frequently reported as elevated, while markers of bone formation, including BALP, osteocalcin, and PINP, show variable or minor changes. Systemic factors like vitamin D deficiency, diabetes, smoking, and alcohol consumption are observationally associated with impaired healing. Cone-beam computed tomography (CBCT) offers a better volumetric assessment compared to traditional X-rays.

Chronic periapical lesions are characterized by a complex osteoimmune imbalance. While integrating biomarkers with advanced imaging represents a promising research avenue, further validation is required before these strategies can be implemented in routine clinical practice.