RESUMO
The aim was to evaluate the antibacterial efficacy and penetration depth into dentinal tubules of a solution of chitosan nanodroplets (NDs) loaded with Benzalkonium Chloride (BAK). Seventy-two human single-root teeth with fully formed apex were used. Cylindrical root dentin blocks were longitudinally sectioned and enlarged to a size of a Gates Glidden drill #4. After sterilization, root canals were infected with Enterococcus faecalis ATCC 29212 and further incubated for three weeks. Specimens were assigned to three experimental groups (n = 20), plus positive (n = 6) and negative (n = 6) controls. In the first group, irrigation was achieved with 2 mL of NDs solution loaded with BAK (NDs-BAK), in the second with 2 mL of 5% sodium hypochlorite (NaOCl) and in the last with 2 mL of 2% chlorhexidine (CHX). Specimens were rinsed and vertically fractured. Confocal laser scanning microscopy (CLSM) and viability staining were used to analyze the proportions of dead and live bacteria quantitatively. The volume ratio of red fluorescence (dead) was calculated in 3D reconstructions. Data were analyzed by one-way ANOVA and post hoc Bonferroni tests (p < 0.05). The ratio of red fluorescence over the whole green/red fluorescence resulted in a significant comparison of NDs-BAK with NaOCl (p < 0.01) and NaOCl with CHX (p < 0.01). No differences were found between NDs-BAK and CHX (p > 0.05). The mean depth of efficacy was, respectively: NDs-BAK 325.25 µm, NaOCl 273.36 µm and CHX 246.78 µm with no statistical differences between groups. The NaOCl solution showed the highest antimicrobial efficacy, but nanodroplets with BAK seemed to have the same effect as CHX with a high depth of efficacy.
RESUMO
AIM: The aim of the study was to achieve the endodontic treatment of a second maxillary molar with abnormal anatomy through cone-beam computed tomography (CBCT) analysis and three-dimensional (3D) printing. BACKGROUND: A patient arrived referring recurrent abscesses, spontaneous pain, and the difficulty to eat properly; a diagnosis of tooth necrosis was made. The periapical X-ray showed an abnormal anatomy of the tooth. CASE DESCRIPTION: The preoperative analysis of the tooth morphology was performed through CBCT analysis. The 3D scans were reconstructed through a dedicated software application (Mimics) to visualize the abnormal anatomy and detect the root canal morphology. Moreover, a 3D printed model was created to plan the clinical stage. Canal shaping was achieved with ProGlider and ProTaper Next techniques, and the root canal filling was performed with a carrier-based technique. CONCLUSION: The limits of this case were the low definition of the CBCT owned by the patient and the difficulties during the scouting of the canals due to the abnormal endodontic space complicated by narrow and flat canals. The software reconstruction allowed a 3D high-definition preclinical analysis of the tooth anatomy. CLINICAL SIGNIFICANCE: Both digital analysis and printed models based on CBCT scans seemed fundamental to preclinically understand the abnormal endodontic anatomy.
