Enhancing Antibiotic Efficacy in Regenerative Endodontics by Improving Biofilm Susceptibility.

INTRODUCTION: Various strategies have been researched to enhance the susceptibility of biofilms, given their tolerance to antibiotics. This study evaluated the effect of the anti-microbial peptide nisin in association with antibiotics used in regenerative endodontics, exploring different treatment times and biofilm growth conditions. METHODS: A mixture of 10 bacterial species was cultivated on dentin specimens anaerobically for 21 days. Biofilms were treated with 1 mL of high-purity nisin Z (nisin ZP, 200 µg/mL) and a triple antibiotic mixture (TAP: ciprofloxacin + metronidazole + minocycline, 5 mg/mL), alone or in combination. The effectiveness of antimicrobial agents was assessed after 1 and 7 days. During the 7-day period, biofilms were treated under 2 conditions: a single dose in a nutrient-depleted setting (ie, no replenishment of growth medium) and multiple doses in a nutrient-rich environment (ie, renewal of medium and antimicrobial agents every 48 h). After treatments, biofilm cells were dispersed, and total colony-forming units were counted. RESULTS: After 1 d-treatment, nisin ZP + TAP resulted in 2-log cell reduction compared to TAP alone (P < .05). After 7 d-treatment with a single dose, nisin ZP + TAP and TAP reduced bacteria to nonculturable levels (P < .05), whereas repeated antimicrobial doses did not eliminate bacteria in a nutrient-rich environment. No bacterial reduction was observed with nisin ZP alone in any treatment time. CONCLUSIONS: The additional use of nisin improved the TAP activity only after a short exposure time. Longer exposure to TAP or nisin + TAP in a nutrient-deprived environment effectively eliminated biofilms.

Laser therapy as an adjunct in the treatment of sodium hypochlorite extrusion through a root perforation: a case report.

Accidental sodium hypochlorite extrusion can occur during endodontic irrigation procedures. The symptoms appear immediately and include severe pain, swelling, and probable tissue necrosis adjacent to the root of the treated tooth. Treatment of sodium hypochlorite extrusion involves immediate and copious saline irrigation to neutralize the area and prescription of analgesic, anti-inflammatory, and antibiotic medications. Low-level laser therapy (LLLT) might be useful as an adjuvant treatment for damaged soft tissues to improve healing. This case report describes the treatment of accidental extrusion of 1% sodium hypochlorite through a root canal perforation in a mandibular incisor during endodontic treatment. The extrusion caused minor swelling within the mentolabial sulcus and a large area of necrosis in the gingivolabial mucosa and right edentulous premolar area. Conventional treatment was performed in association with LLLT. Clinical and radiographic examinations after 6 months showed complete healing of the necrotic area without paresthesia and the repair of apical tissues.

Physical properties and interfacial adaptation of three epoxy resin-based sealers.

INTRODUCTION: The aim of the study was to evaluate the radiopacity, solubility, flow, film thickness, setting time, and adaptation to the root canal walls of 3 epoxy resin-based sealers: AH Plus, Acroseal, and Adseal. METHODS: Physical tests were performed following American National Standards Institute/American Dental Association's requirements. For interfacial adaptation analysis, 30 maxillary canines were shaped by using ProTaper instruments. The specimens were divided into 3 groups (n = 10): group 1, AH Plus; group 2, Acroseal; and group 3, Adseal. The sealers were mixed with rhodamine B dye, and the canals were filled by using the lateral compaction technique. The percentage of gaps and voids area was calculated at 2, 4, and 6 mm levels from the apex. Statistical evaluation was performed by using analysis of variance for physical analysis and nonparametric Kruskal-Wallis and Dunn tests for interfacial adaptation (P < .05). RESULTS: No statistical differences were found for adaptation, percentage of voids, solubility, flow, and film thickness among the sealers (P > .05). AH Plus was significantly more radiopaque (P < .05). For the setting time, there were statistical differences among all the studied sealers (P < .05). CONCLUSIONS: AH Plus, Acroseal, and Adseal presented similar root canal adaptation, solubility, flow, and film thickness. Statistical differences were found for radiopacity and setting time (P < .05).