Overlapping protective and destructive regulatory pathways in apical periodontitis.
BACKGROUND
Protective and destructive immunoreactions take place simultaneously in apical periodontitis. However, the same reactions defending the periapical area from infection-derived damage may also result in host tissue injury.


METHODS
The inflammatory reaction of the periapical tissues is self-limited. Regeneration of the injured tooth-supporting structures may follow elimination of the causative microbial irritation.


RESULTS
Recent experimental and clinical observations have identified important interplay between positive and negative regulatory pathways. A network of stimulatory and inhibitory feedback loops may influence the intensity of the defense and inflammatory responses and the balance between bone resorption and regeneration, resulting in lesion expansion or healing of apical periodontitis.


CONCLUSIONS
We critically discuss research data on regulatory mechanisms that control the activity of host effector cells and signaling molecules during interactions with pathogenic microbes.
Department of Restorative Dentistry, Faculty of Dentistry, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary. Electronic address: marton.ildiko@dental.unideb.hu.
Ildikó J
IJ
Márton
Department of Pediatric Hematology-Oncology, Institute of Pediatrics, Faculty of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.
Csongor
C
Kiss
D016301:Alveolar Bone Loss / Q000276:immunology; D001861:Bone Regeneration / Q000276:immunology; D025461:Feedback, Physiological; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology; D018836:Inflammation Mediators / Q000276:immunology; D010485:Periapical Periodontitis / Q000276:immunology* / Q000382:microbiology; D015398:Signal Transduction / Q000276:immunology*
D018836:Inflammation Mediators
Apical periodontitis; bone resorption; cytokines; immunity; inflammation; stem cells