Chlorhexidine Prevents Root Dentine Mineral Loss and Fracture Caused by Calcium Hydroxide over Time

Radiomics-Driven CBCT Texture Analysis as a Novel Biosensor for Quantifying Periapical Bone Healing: A Comparative Study of Intracanal Medications

This study aimed to evaluate the effectiveness of two intracanal medications in promoting periapical bone healing following endodontic treatment using radiomics-enabled texture analysis of cone-beam computed tomography (CBCT) images as a novel biosensing technique. By quantifying tissue changes through advanced image analysis, this approach seeks to enhance the monitoring and assessment of endodontic treatment outcomes. Thirty-four single-rooted teeth with pulp necrosis and periapical lesions were allocated to two groups (17 each): calcium hydroxide +2% chlorhexidine gel (CHX) and Ultracal XS®. CBCT scans were obtained immediately after treatment and three months later. Texture analysis performed using MaZda software extracted 11 parameters based on the gray level co-occurrence matrix (GLCM) across two inter-pixel distances and four directions. Statistical analysis revealed significant differences between medications for S [0,1] inverse difference moment (p = 0.043), S [0,2] difference of variance (p = 0.014), and S [0,2] difference of entropy (p = 0.004). CHX treatment resulted in a more organized bone tissue structure post-treatment, evidenced by reduced entropy and variance parameters, while Ultracal exhibited less homogeneity, indicative of fibrous or immature tissue formation. These findings demonstrate the superior efficacy of CHX in promoting bone healing and underscore the potential of texture analysis as a powerful tool for assessing CBCT images in endodontic research.

Physicochemical and histological analysis of an experimental endodontic repair material containing 45S5 bioactive glass

This study aimed to evaluate the maximum compressive strength, the modulus of elasticity, pH variation, ionic release, radiopacity and biological response of an experimental endodontic repair cement based on 45S5 Bioglass^®. An in vitro and in vivo study with an experimental endodontic repair cement containing 45S5 bioactive glass was conducted. There were three endodontic repair cement groups: 45S5 bioactive glass-based (BioG), zinc oxide-based (ZnO), and mineral trioxide aggregate (MTA). In vitro tests were used to evaluate their physicochemical properties: compressive strength, modulus of elasticity, radiopacity, pH variation, and the ionic release of Ca⁺ and PO₄. An animal model was used to evaluate the bone tissue response to endodontic repair cement. Statistical analysis included the unpaired t-test, one-way ANOVA and Tukey's test. BioG showed the lowest compressive strength and ZnO showed the highest radiopacity among the groups, respectively (p < 0.05). There were no significant differences in the modulus of elasticity among the groups. BioG and MTA maintained an alkaline pH during the 7 days of evaluation, both at pH 4 and in a pH 7 buffered solutions. PO4 was elevated in BioG, peaking at 7 days (p < 0.05). Histological analysis showed less intense inflammatory reactions and new bone formation in MTA. BioG showed inflammatory reactions that decreased over time. These findings suggest that the BioG experimental cement had good physicochemical characteristics and biocompatibility required for bioactive endodontic repair cement.

Effect of different chelating agents on dentinal crack formation

The present study aimed to evaluate the degree of crack formation during canal preparation using reciprocating files. A total of 120 incisor teeth were divided into eight groups according to irrigation protocol (n = 15). The irrigation solution and chelating agents included distilled water, sodium hypochlorite (NaOCl), citric acid, maleic acid, peracetic acid, ethylenediaminetetraacetic acid (EDTA) gel, and EDTA liquid. The root canals were prepared using reciprocating instruments while one of the agents was present within the root canals. A control group was subjected to neither preparation nor irrigation. The roots were horizontally sectioned 3, 6, and 9 mm away from the apices. The numbers of cracks were recorded. Statistical analyses were performed using a chi-squared test. The chelating agents resulted in similar numbers of cracked sections. The use of one of the chelating agents during preparation using reciprocating instruments appears to be beneficial in reducing crack formation.

In vitro evaluation of local antibiotic delivery via fibrin hydrogel

BACKGROUND/PURPOSE

Fibrin hydrogel is commonly used as hemostatic agent and scaffold but it is questionable for carrying antibiotics. Thus, this study aimed to investigate whether the fibrin hydrogel can be used to deliver the optimal concentration of ciprofloxacin against oral pathogen.

MATERIALS AND METHODS

The optimal concentration of ciprofloxacin was investigated from broth microdilution technique against three common oral bacteria. Ten times the bactericidal concentration of ciprofloxacin loaded to 0.4% fibrin hydrogel was observed by using a confocal laser scanning microscope and then was left in tris-buffer saline solution (TBS) for 0, 1, 12, 24, 72 and 168 h in parallel with the control group of ciprofloxacin loaded to 0.5% alginate hydrogel and ciprofloxacin solution. Spectrophotometer was used to analyze the accumulated drug release from the collected TBS, of which the measurement method was calibrated. The efficacy of the released ciprofloxacin was tested using an agar well diffusion assay. The inhibition zone of the released ciprofloxacin from fibrin hydrogel was statistically compared with 150 and 1500 μg/ml ciprofloxacin solution, while non-loaded fibrin hydrogel served as the control.

RESULTS

The results revealed that minimum inhibitory concentration was 1-2 μg/ml and minimum bactericidal concentration was 4-15 μg/ml. The fibrin hydrogel gradually released ciprofloxacin until 168 h while the alginate hydrogel immediately liberated all the loaded ciprofloxacin within an hour. The agar well diffusion significantly showed greater clear zone in fibrin hydrogel loaded ciprofloxacin compared to non-loaded fibrin hydrogel but not with ciprofloxacin in TBS.

CONCLUSION

The results suggested that fibrin hydrogel can be used for local ciprofloxacin delivery without interfering the efficacy of ciprofloxacin.