Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: a randomized clinical trial. Antibacterial activity of 2% chlorhexidine gluconate and 5.25% sodium hypochlorite in infected root canal: in vivo study. Antimicrobial effect of 0.2% chlorhexidine in infected root canals. Effect of sodium hypochlorite with the addition of a proteolytic enzyme on postoperative discomfort: a multicenter randomized clinical trial. Influence of sodium hypochlorite-based irrigants on the susceptibility of intracanal microbiota to biomechanical preparation. The effect of chlorhexidine as an endodontic disinfectant. In vivo evaluation of microbial reduction after chemo-mechanical preparation of human root canals containing necrotic pulp tissue. Antibacterial efficacy of MTAD final rinse and two percent chlorhexidine gel medication in teeth with apical periodontitis: a randomized double-blinded clinical trial. In vivo evaluation of chlorhexidine gluconate solution and sodium hypochlorite solution as root canal irrigants.
To compare the levels of postoperative pain after cleaning and shaping of root canals using two different root canal irrigants for debridement.
                Forty patients with irreversible pulpitis, pulp necrosis and non-vital teeth exhibiting acute apical periodontitis requiring root canal treatment were included. At random, canals were cleaned and shaped with the following protocols. 2% chlorhexidine solution in group I and 5.25% sodium hypochlorite solution in group II were used as an irrigants. Access cavities were closed with a sterile cotton pellet and cavit. The patients recorded degree of pain at various time intervals after cleaning and shaping on a visual analogue scale for 1 week.
                The mean pain score for group I was between 0.65 and 3.35 and for group II was between 0.95 and 4.50. There was significant difference in the pain level between the two groups only at 6 th hour postoperatively (P<0.05) and the pain was more in sodium hypochlorite group.
                More pain was present in teeth irrigated using 5.25% sodium hypochlorite when compared to that in teeth irrigated using 2% chlorhexidine solution. Significant difference in pain level was present only at 6th hour postoperatively, and at all other periods (24 th hour, 4 th and 7 th days) there was no significant difference in pain level between the two groups. In this study, the antibacterial activity of the different antibacterial solutions using as root canal irrigant was compared in the teeth with pulpal necrosis and with periapical pathosis. Thirty root canals of incisors and premolars of 20 patients were used. Before and after the root canal preparation, two canal samples were obtained by a harvesting method using a sterile paper point in the first appointment. During the biomechanical preparation, both irrigant solutions were used for each tooth which were randomly divided into two groups. Last samples were also obtained before the root filling procedure. Samples obtained from the root canals were subjected to microbiologic processing, including anaerobic incubation on trypticase soy agar for 5 to 7 days. After counting of CFU on the plates, we concluded that both chlorhexidine gluconate and sodium hypochlorite were significantly effective to reduce the microorganisms in the teeth with necrotic pulp, periapical pathologies, or both, and could be used successfully as an irrigant solution. The aim of this study was to identify bacteria from the infected root canals of teeth with chronic apical periodontitis, and to evaluate the antibacterial effect of 0.2% chlorhexidine (CHX), as an irrigant, in reducing the microbial flora 48h after root canal preparation. A total of 44 subjects were randomly divided in the experimental group and the control group. The first bacterial samples from all root canals were obtained in the beginning, before any treatment. During mechanical instrumentation, root canals were irrigated three times, with 0.2% CHX in the experimental group, and with saline solution in the control group. All canals were dried and temporarily sealed with zinc oxide-sulfate cement. After 48 h the second samples were obtained. Bacterial samples were subjected to microbiologic processing. The study indicates that 0.2% CHX is significantly effective in reducing the microbial flora, and could be used as an irrigant solution. The purpose of this study was to compare the patient's postoperative discomfort when root canal irrigation was performed either with standard sodium hypochlorite or with sodium hypochlorite with the adjunct of a proteolytic enzyme.
                Two hundred patients were endodontically treated in two clinics. The type of irrigant to be used during root canal instrumentation was randomly assigned. Final irrigation was done using EDTA 17%. The canals were filled by warm vertical condensation with guttha-percha and the coronal seal was made using IRM. Patients were given a questionnaire to assess pain and swelling and the number of analgesics and other drugs taken during the first week after treatment.
                A total of 166 questionnaires could have been evaluated. No significant difference was found between groups for pain, swelling and analgesics taken. Moderate pain and swelling was reported only in the first two days after treatment. No antibiotics use was reported. No guttha-percha excess beyond root apex was found by radiographic assessment.
                The irrigating solution containing a proteolytic enzyme does not produce greater postoperative discomfort as compared to the conventional sodium hypochlorite in patients undergoing endodontic therapy. This study evaluated the microbiological conditions of root canals, using smears and culture from anterior teeth and premolars with necrotic pulps associated with chronic periapical pathologies, before and after biomechanical preparation (BMP). During double-flared instrumentation, 1, 2.5 and 5% sodium hypochlorite (NaOCl)-based irrigants were used in 3 groups: GI (n=39), GII (n=36) and GIII (n=36), respectively. Before BMP, all cultures were positive and the smears showed microbiologically diverse morphotypes, including fusiforms, pleomorphic, rods, cocci and filaments. Quantitatively, 20, 20 and 23 morphotypes were identified in GI, GII and GIII, respectively). After BMP, the percentages of negative cultures in GI, GII and GIII were 74.2%, 86.3% and 93.4% (p>0.05) and the number of morphotypes decreased to 14, 15 and 5, respectively. All teeth with 2 root canals and/or associated fistulas were microbiologically negative after BMP, regardless of irrigant concentration. Gram-negative morphotypes were more susceptible to the action of irrigants. After irrigation with 5% NaOCl, only structural arrangements consisting of Gram-positive cocci and bacilli persisted. Thus, BMP plus 5% NaOCl offered the best antiseptic potential because in the few positive cultures a significant reduction in the number of microbiological morphotypes was also shown (p<0.05). The purpose of this study was to establish whether addition of a 2% chlorhexidine rinse to a conventional treatment protocol enhances the rate of the successful disinfection of the root canal system in vivo.
                Twenty-four teeth with infected necrotic pulps and resorbing apical periodontitis were treated with a conventional technique in which 1% NaOCl as irrigant was used. Half of the cases received an additional rinse with 2% chlorhexidine. Prereduced thioglycollate medium was used to take cultures that were incubated for 4 weeks.
                Cultivable bacteria were retrieved at the conclusion of the first visit in 1 out of 12 chlorhexidine cases whereas in the control group 7 out of 12 cases showed growth. This difference was significant (P < .05).
                The findings are clinically important. To determine in vivo, the degree of microbial reduction after chemo-mechanical preparation of human root canals containing necrotic pulp tissue when using two endodontic irrigating reagents, sodium hypochlorite (NaOCl) or chlorhexidine gel (CHX).
                Thirty-two single rooted teeth with necrotic pulp were divided into two groups. One group (n=16) was irrigated with 2.5% NaOCl, whilst the other group (n=16) was irrigated with 2% CHX gel. Assessment of the bacterial load was accomplished by use of real-time quantitative-polymerase chain reaction (RTQ-PCR) directed against the small subunit ribosomal DNA using the SYBRGreen and TaqMan formats. Statistical analysis was performed using the Mann-Whitney test. For contrast, bacterial load was also determined by traditional culture techniques.
                The bacterial load was reduced substantially in both groups (over 96%). However, using RTQ-PCR the bacterial load before and after chemo-mechanical preparation was greater when compared with evaluation using colony forming units (CFU). Furthermore, as measured by RTQ-PCR, the bacterial reduction in the NaOCl-group (SYBRGreen 99.99%; TaqMan: 99.63%) was significantly greater (P<0.01) than in the CHX-group (SYBRGreen 96.62%; TaqMan: 96.60%). According to culture technique 75% of cases were free of bacteria after chemo-mechanical preparation in the NaOCl-group, whilst 50% of cases were bacteria free in the CHX-group.
                NaOCl has not only a higher capacity to kill microorganisms but is also more able to remove cells from the root canal. Clinical assessment of the efficacy of novel root canal disinfection protocols is an important focus in endodontic research. This randomized double-blinded study assessed the antibacterial efficacy of a final rinse with BioPure MTAD (MTAD) and intracanal medication with 2% chlorhexidine gel (CHX) in teeth with apical periodontitis.
                Canals in 30 teeth (single-rooted and multi-rooted) were prepared by using 1.3% NaOCl, rinsed with MTAD or saline in random sequence, medicated with CHX for 7 days, irrigated with 1.3% NaOCl, and filled. Bacteriologic root canal samples were obtained by aspiration before (1A) and after (1B) canal preparation, after the final rinse (1C), after CHX was flushed (2A), and after final irrigation (2B). Bacteria were enumerated by epifluorescence-microscopy (EFM) by using 2 staining methods and by colony-forming-unit (CFU) counts after 14 days of incubation.
                Bacterial counts (EFM) in 1B were greater than 95% decreased from 1A. Low bacterial densities in 1B, 1C, 2A, and 2B did not differ significantly from each other. EFM counts were consistently higher than CFU counts.
                The final rinse with MTAD and medication with CHX did not reduce bacterial counts beyond levels achieved by canal preparation with NaOCl. nan
Although root canal irrigants such as sodium hypochlorite and chlorhexidine appear to be effective at reducing bacterial cultures when compared to saline, most of the studies included in this review failed to adequately report these clinically important and potentially patient-relevant outcomes. There is currently insufficient reliable evidence showing the superiority of any one individual irrigant. The strength and reliability of the supporting evidence was variable and clinicians should be aware that changes in bacterial counts or pain in the early postoperative period may not be accurate indicators of long-term success. Future trials should report both clinician-relevant and patient-preferred outcomes at clearly defined perioperative, as well as long-term, time points.