Norberti Bernardinelli

Activity of endodontic antibacterial agents against selected anaerobic bacteria

The antimicrobial activity of substances used as antibacterial agents (solutions of 10% calcium hydroxide, camphorated paramonochlorophenol - PMCC, 2% chlorhexidine digluconate and 10% castor oil plant detergent) on anaerobic bacteria (Fusobacterium nucleatum ATCC 25586, Prevotella nigrescens ATCC 33563, Clostridium perfringens ATCC 13124 and Bacteroidesfragilis ATCC 25285), using a broth dilution technique, was evaluated in vitro. For determination of minimum inhibitory and minimum bactericide concentrations (MIC and MBC), two culture broths, Reinforced Clostridial Medium (RCM) and supplemented Brucella, standardized inoculum and serially diluted solutions were used. All antibacterial agents presented antimicrobial activity that varied for different bacteria. There were no differences in the performance of the two broths. Chlorhexidine digluconate was the most effective, with the lowest MICs, followed by castor oil detergent, PMCC and calcium hydroxide. C. perfringens and B. fragilis were the most resistant bacteria to all agents.

Bilateral mandibular canines with two roots and two separate canals: case report

The mandibular canine is usually considered a single-rooted tooth with a single root canal. However, two canals and more rarely two roots may also occur. This paper reports the case of a patient with bilateral mandibular canines with two roots and two root canals. The initial periapical radiographs of the mandibular right and left canines for endodontic treatment revealed the presence of two roots in each tooth. After coronal opening, the cervical third was prepared with a SX file of the ProTaper system and root canal length was confirmed using Root ZX electronic apex locator. Root canal preparation was completed with the series of ProTaper instruments and the root canal was filled with gutta-percha and an epoxy resin-based endodontic sealer according to Taggers hybrid technique. The final radiographs showed two well-obturated canals ending at the electronically located apexes. The 6-month posttreatment follow-up showed apparent clinical and radiographic success. Clinicians should always consider the presence of anatomical variations in the teeth during endodontic treatments. Despite the low prevalence, variations may occur in the number of roots and root canals of mandibular canines, as demonstrated in this case report.

Heat-killed Enterococcus faecalis Alters Nitric Oxide and CXCL12 Production but not CXCL8 and CCL3 Production by Cultured Human Dental Pulp Fibroblasts

INTRODUCTION Fibroblasts are the most abundant cells in dental pulp. To investigate their capacity to produce the chemokines CCL3, CXCL8, and CXCL12 as well as nitric oxide (NO), we evaluated the production of these mediators in supernatants of cultured human dental pulp fibroblasts (HDPF) stimulated by heat-killed Enterococcus faecalis (HKEF). METHODS Primary cultures of HDPF were stimulated with medium alone or HKEF (1:1, 10:1, or 100:1 bacteria:fibroblast) for 1, 6, and 24 hours. Chemokines and NO were assessed through enzyme-linked immunosorbent assay and Griess reaction, respectively. Statistical analysis was performed by using analysis of variance and Tukey post test. RESULTS CCL3 was not detected, whereas constitutive CXCL8 was not affected. Production of CXCL12 was increased at 1 and 6 hours, and NO was increased at the concentration of 1:1 bacteria:fibroblast at 24 hours. Viability and proliferation assays did not reveal cell number differences. CONCLUSIONS These findings demonstrate that heat-killed E. faecalis is able to increase production of CXCL12 and NO by HDPF.