The Effect of Different Antibiotics Disinfection Protocols on Chemokines Expression in Mature Teeth with Chronic Apical Periodontitis. An immunohistochemical animal study

Abstract

The aim of this study is to evaluate the effect of different disinfecting antibiotic combinations regimens on certain inflammatory biomarkers in mature teeth with chronic apical periodontitis in dogs. The targeted biomarkers were IL-17 which is a pro-inflammatory cytokine, TGF- β which is a pleiotropic cytokine with dual pro or anti-inflammatory effects, and MMP-13 which is a collagenase of the metalloproteinase family. Three different antibiotics disinfectants were used to assess their effect: Ciprofloxacin, DAP (equal volumes of metronidazole and Doxycycline) and TAP (similar to DAP with an added similar volume of Doxycycline). Eight mature dogs were selected for this study. From each dog, three two-rooted premolars from the lower jaw unilaterally were used; with a total 6 root apices/dog. Access cavities were made, periapical pathosis initiation was provoked and the teeth were left exposed to the oral environment for 4 weeks. The dogs were then randomly allocated to four groups: two dogs per group: Group I: which represent the control group where only apicectomy was done after 4 weeks from lesion induction to collect the formed periapical lesions and assess the “reference levels” of the biological markers of interest.

Remaining groups received a disinfection step as follows: Group II: disinfection using CP. Group III: disinfection using DAP Group IV: disinfection using TAP After 4 weeks, teeth of groups II, III and IV were cleaned and shaped under aseptic conditions and the use of NaOCl and EDTA before the placement of CP, DAP or TAP respectively as intracanal medications and providing coronal seal. 4 weeks after apicectomy procedures were performed as in group I to collect the sample tissues. All obtained 48 samples collected from the 4 groups (12 roots/group) were processed for the immunofluorescent examination of the biomarkers’ level change from reference level in correlation to the disinfecting antibiotic used. From each sample a series of sequential calibrated photomicrographs were taken with the designated light filter suitable for the used fluorochrome. Using ZEN 2 blue edition image analysis software obtained images were quantified for average intensity (intensity per image area) of the fluorochrome specific for the cytokine assessed, and thus its expression; the greater the intensity, the greater the level.