Impact of N-acetylcysteine (NAC) and calcium hydroxide intracanal medications in primary endodontic infection: a randomized clinical trial.

OBJECTIVES: This RCT investigated the impact of N-acetylcysteine (NAC) and calcium hydroxide [Ca(OH)2] intracanal medications (ICMs) in primary endodontic infection with apical periodontitis (PEIAP). MATERIALS AND METHODS: Thirty-six teeth with PEIAP were randomly divided into groups according to the ICM: NAC, Ca(OH)2 + saline solution (SSL), and Ca(OH)2 + 2% chlorhexidine-gel (2% CHX-gel) (all, n = 12). Root canal samples (RCSs) were collected before (s1) and after instrumentation (s2) and after 14 days of ICM (s3). Chemomechanical preparation (CMP) was performed with a Reciproc file and 2.5% NaOCl. Checkerboard DNA-DNA hybridization was used to assess 40 target bacteria species. RESULTS: At s1, bacterial DNA was detected in 100% of RCSs (36/36). All 40 bacterial species were found in PEIAP. The mean number of species per RCS was 17.92 ± 13.18. The most frequent bacteria were S. mitis (65%), E. nodatum (63%), E. faecalis (63%), F. nucl sp vicentii (58%), T. forsythia (58%), and F. periodonticum (56%). CMP reduced the mean number of species per RCS to 6.8 ± 2.36 (p < 0.05). At s3, the intragroup analysis revealed a broader antimicrobial activity for Ca (OH)2 + 2% CHX-gel and NAC than Ca(OH)2 + SSL (p < 0.05). NAC eliminated 8/12 bacteria species resistant to both Ca (OH)2 ICMs, including P. micra, P. nigrescens, T. denticola, A. israelii, P. endodontalis, P. acnes, C. ochracea, and E. corrodens. CONCLUSIONS: Ca (OH)2 + 2% chlorhexidine gel (2% CHX gel) showed a greater bacterial elimination over the number of bacterial species; however, NAC eliminated 8/12 bacteria species resistant to both Ca (OH)2 ICMs (RBR-3xbnnn). CLINICAL RELEVANCE: The use of intracanal medication with a broad antimicrobial activity can optimize root canal disinfection. Ca(OH)2 + 2% CHX gel and NAC showed a broader antimicrobial activity than Ca(OH)2 + SSL against endodontic pathogens in primary root canal infection. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (REBEC), No. RBR-3xbnnn.

Resolution of Nasal Sinus Tract after Endodontic Therapy: A Case Report with Microbial Analysis.

This case report describes the resolution of a 20-year misdiagnosed nasal sinus tract after root canal therapy with multiple sessions of calcium hydroxide (Ca[OH]2) intracanal medication. Clinical evaluation, including diagnostic testing and sinus tract tracing, was performed followed by a cone-beam computed tomographic scan and 3-dimensional reconstruction of the apical lesion. Bacteria and endotoxin analyses were performed from the nasal sinus tract and paired root canal infection before (s1) and after instrumentation (s2) and after 7 (s3), 14 (s4), and 21 (s5) days of Ca(OH)2 medication. The bacteria analysis was performed using the checkerboard DNA-DNA hybridization method and endotoxin quantified by the limulus amebocyte lysate method. A similar microbiota profile was found in the sinus tract and paired root canal infection. No target bacterial species were detected in the root canal at s2, s3, and s5. In contrast, Actinomyces israellii and Eubacterium nodatum were detected at s4. Differences in bacterial detection were found between s1 × s2, s3 × s4, and s4 × s5 (all P < .05). Endotoxin was detected in the root canal at all sampling times. Differences in the levels of endotoxin were found between s1 × s2, s2 × s3, and s3 × s4 (all P < .05).The bacterial analysis revealed similar microbiota profiles present in the nasal sinus tract and paired root canal infection with the participation of a wide variety of gram-positive and -negative species. Additionally, root canal therapy with multiple sessions of Ca(OH)2 intracanal medication for 21 days was effective in disinfecting the root canal system and resolving the nasal sinus tract.