Monitoring the effectiveness of root canal procedures on endotoxin levels found in teeth with chronic apical periodontitis

Objective:

The aim of this study was to monitor the effectiveness of root canal procedures by using different irrigants and intracanal medication on endotoxin levels found in root canals of teeth with chronic apical periodontitis.

Material and Methods:

Thirty root canals of teeth with pulpal necrosis associated with periapical lesions were selected and randomly divided into groups according to the irrigants used: GI - 2.5% NaOCl, GII - 2% chlorhexidine (CHX) gel, and GIII - saline solution (SS) (all, n=10). Samples were collected with sterile/apyrogenic paper points before (S1) and after root canal instrumentation (S2), after use of 17% ethylenediaminetetraacetic acid (EDTA) (S3), and after 30 days of intracanal medication (Ca(OH)₂+SS) (S4). A turbidimetric kinetic Limulus Amebocyte Lysate assay was used for endotoxin measurement.

Results:

Endotoxins were detected in 100% of the root canals investigated (30/30), with a median value of 18.70 EU/mL. After S2, significant median percentage reduction was observed in all groups, irrespective of the irrigant tested: 2.5% NaOCl (99.65%) (GI), 2% CHX (94.27%) (GII), and SS (96.79%) (GIII) (all p<0.05). Root canal rinse with 17% EDTA (S3) for a 3-minute period failed to decrease endotoxin levels in GI and a slight decrease was observed in GII (59%) and GIII (61.1%) (all p>0.05). Intracanal medication for 30 days was able to significantly reduce residual endotoxins: 2.5% NaOCl (90%) (GI), 2% CHX (88.8%) (GII), and SS (85.7%) (GIII, p<0.05). No differences were found in the endotoxin reduction when comparing s2 and s4 treatment groups.

Conclusion:

Our findings demonstrated the effectiveness of the mechanical action of the instruments along with the flow and backflow of irrigant enduring root canal instrumentation for the endotoxin removal from root canals of teeth with chronic apical periodontitis. Moreover, the use of intracanal medication for 30 days contributed for an improvement of endotoxin reduction.     

金栀含漱液用于感染根管冲洗消毒的细菌学观察

目的:观察金栀含漱液对感染根管冲洗消毒的抗菌效果。方法:选择27例患者的感染根管患牙30颗,随机分为实验组和对照组,每组15颗。实验组采用金栀2倍稀释液冲洗根管,浓缩液作为根管消毒药物。对照组采用氯亚明冲洗根管,氢氧化钙药尖消毒根管。根管预备冲洗前、预备冲洗后、封药后分别取细菌样本进行厌氧培养、分离和鉴定,计算并采用重复测量的方差分析比较2组细菌检出率、CFU随时间的变化趋势。结果:实验组专性厌氧菌的检出率由73.3%下降到预备冲洗后的46.7%和封药后的13.3%,对照组厌氧菌的检出率由73.3%下降到预备冲洗后的20.0%和封药后的26.7%,2组细菌检出率无统计学差异(P=0.9721)。实验组专性厌氧菌CFU由1462.9下降为预备冲洗后的27.9和封药后的15.7,对照组厌氧菌CFU由1402.8下降到预备冲洗后的14.0和封药后的45.1,2组细菌检出量无统计学差异(P=0.688)。结论:金栀含漱液对感染根管内厌氧菌有良好的抗菌效果。     

In vitro antimicrobial and anti-endotoxin action of Zingiber Officinale as auxiliary chemical and medicament combined to calcium hydroxide and chlorhexidine

Abstract

Objective. This study was conducted in vitro to compare the effectiveness of Zingiber Officinale as an auxiliary chemical substance followed by placement of different intra-canal medication in removing endotoxins and cultivable micro-organisms from infected root canals. Materials and methods. Seventy-two root canals were contaminated with Enterococcus faecalis, Candida albicans and Escherichia coli for 28 days. After, the teeth were instrumented using Zingiber Officinale and divided into six groups according to the intra-canal medication: chlorhexidine gel; calcium hydroxide + chlorhexidine gel; glycolic ginger extract; calcium hydroxide + glycolic ginger extract; calcium hydroxide + saline solution and saline solution (control). Sample collections were performed after root canal contamination (Baseline; S1), after instrumentation (S2), 7 days after instrumentation (S3), after 14 days with intra-canal medication (S4) and 7 days after removal of intra-canal medication (S5). The results were analyzed by the Kruskal-Wallis and Dunn tests. Results. It was observed that in S2 and S3 there was significant reduction of the micro-organisms and the quantity of endotoxins after instrumentation. In samples S4 and S5 there was complete elimination of micro-organisms and significant reduction of endotoxins. Conclusion. It was concluded that Zingiber Officinale as an auxiliary chemical substance was effective on the micro-organisms tested, yet was unable to eliminate the endotoxins. Similarly, the intra-canal medication were effective on micro-organisms, yet did not completely eliminate the endotoxins.     

The role of intracanal medication in root canal treatment

The role of intracanal medication as a root canal dressing is re-examined. In pulpectomy and some root canal treatments, where the root canal contains vital pulp tissue, it is doubtful whether a routine intracanal medicament is needed. In infected root canals, intracanal medication has been advocated for many purposes. An intracanal medicament is used to: (i) eliminate any remaining bacteria after canal instrumentation; (ii) reduce inflammation of periapical tissues and pulp remnants; (iii) render canal contents inert and neutralize tissue debris; (iv) act as a barrier against leakage from the temporary filling; (v) help to dry persistently wet canals. However, most of the indications for intracanal medicaments are questionable. Intracanal medicaments should only be used for root canal disinfection as part of controlled asepsis in infected root canals, and their role is secondary to cleaning and shaping of the root canal. Thorough canal debridement and adequate canal preparation are more pertinent, and their importance is emphasized. Bacteriological sampling may be necessary if a tooth does not respond to treatment, to help in the choice of intracanal medicament.     

Bacterial quantification in teeth with apical periodontitis related to instrumentation and different intracanal medications: a randomized clinical trial

The antibacterial efficacy of intracanal medication with calcium hydroxide [Ca(OH)2], 2% chlorhexidine gel (CHX), and a combination of both [Ca(OH)2/CHX] was assessed in teeth with chronic apical periodontitis. Thirty-three canals were instrumented, randomly divided into three groups, and medicated with either Ca(OH)2, CHX, or Ca(OH)2/CHX. Bacteriological samples obtained from the operative field and the root canals before (S1) and after instrumentation (S2) in the first treatment session, and after medication (S3) in the second session 1 week later, were assessed for bacterial growth, observed by turbidity and in agar plates, and viable colony-forming unit (CFU) counts. Bacterial growth and CFU counts decreased significantly from S1 to S2 (Mann-Whitney, p<0.05). Differences in growth and counts between S2 to S3 were not statistically significant for all three intracanal medication groups. It was concluded that the antibacterial efficacy of Ca(OH)2, CHX, and Ca(OH)2/CHX was comparable.     

ELIMINATION OF INTRACANAL INFECTION IN DOGS' TEETH WITH INDUCED PERIAPICAL LESIONS AFTER ROTARY INSTRUMENTATION: INFLUENCE OF DIFFERENT CALCIUM HYDROXIDE PASTES

The aim of this study was to evaluate the antiseptic efficacy of rotary instrumentation associated with calcium hydroxide-based pastes prepared with different vehicles and antiseptics. Chronic periapical lesions were experimentally induced in 72 premolar root canals of four dogs. Under controlled asepsis, after initial microbiological sampling (A1), the root canals were instrumented using the ProFile system in conjunction with 5.25% sodium hypochlorite and the intracanal medication was placed. Four experimental groups were formed according to the pastes used: group 1- Calen (n=18), group 2- Calen+CPMC (n=20), group 3- Ca(OH)₂ p.a.+ anaesthetic solution (n=16) and group 4- Ca(OH)₂ p.a.+ 2% chlorhexidine digluconate (n=18). After 21 days, the pastes were removed; the canals were emptied and 96 hours later a second microbiological sample was obtained (A2). The incidence of positive microbiological cultures and the number of cfus in stages A1 and A2 were compared statistically by the Wilcoxon test while the influence of the different treatments in intracanal infection was evaluated by Kruskal-Wallis test at 5% significance level (p<0.05). Large numbers of strict and facultative anaerobes, and viridans group streptococci were found in 100% of root canals of A1 samples. Among A2 samples, all treatments showed significant reduction of cfus and positive cultures (p<0.05), but only groups 3 and 4 showed 100% of root canals free of microorganisms. Rotary instrumentation plus NaOCl 5.25% associated with intracanal medication produced a drastic reduction or elimination of intracanal microbiota, whose performance was not influenced by the nature of the vehicle or the antiseptic added to the Ca(OH)₂ p.a.     

Macrophage Cell Activation with Acute Apical Abscess Contents Determined by Interleukin-1 Beta and Tumor Necrosis Factor Alpha Production

Introduction

This clinical study has investigated the antigenic activity of bacterial contents from exudates of acute apical abscesses (AAAs) and their paired root canal contents regarding the stimulation capacity by levels of interleukin (IL)-1 beta and tumor necrosis factor alpha (TNF-α) throughout the root canal treatment against macrophage cells.

Methods

Paired samples of infected root canals and exudates of AAAs were collected from 10 subjects. Endodontic contents were sampled before (root canal sample [RCS] 1) and after chemomechanical preparation (RCS2) and after 30 days of intracanal medication with calcium hydroxide + chlorhexidine gel (Ca[OH]₂ + CHX gel) (RCS3). Polymerase chain reaction (16S rDNA) was used for detection of the target bacteria, whereas limulus amebocyte lysate was used to measure endotoxin levels. Raw 264.7 macrophages were stimulated with AAA exudates from endodontic contents sampled in different moments of root canal treatment. Enzyme-linked immunosorbent assays were used to measure the levels of TNF-α and IL-1 beta.

Results

Parvimonas micra, Porphyromonas endodontalis, Dialister pneumosintes, and Prevotella nigrescens were the most frequently detected species. Higher levels of endotoxins were found in samples from periapical exudates at RCS1 (P < .005). In fact, samples collected from periapical exudates showed a higher stimulation capacity at RCS1 (P < .05). A positive correlation was found between endotoxins from exudates with IL-1 beta (r = 0.97) and TNF-α (r = 0.88) production (P < .01). The significant reduction of endotoxins and bacterial species achieved by chemomechanical procedures (RCS2) resulted in a lower capacity of root canal contents to stimulate the cells compared with that at RCS1 (P < .05). The use of Ca(OH)₂ + CHX gel as an intracanal medication (RCS3) improved the removal of endotoxins and bacteria from infected root canals (P < .05) whose contents induced a lower stimulation capacity against macrophages cells at RCS1, RCS2, and RCS3 (P < .05).

Conclusions

AAA exudates showed higher levels of endotoxins and showed a greater capacity of macrophage stimulation than the paired root canal samples. Moreover, the use of intracanal medication improved the removal of bacteria and endotoxins from infected root canals, which may have resulted in the reduction of the inflammatory potential of the root canal content.     

Calcium hydroxide intracanal dressing removal with different rotary instruments and irrigating solutions: a scanning electron microscopy study

This study evaluated the efficacy of 2 types of rotary instruments employed in association with sodium hypochlorite (NaOCl) or EDTA in removing calcium hydroxide (CH) residues from root canals dentin walls. Forty-two mandibular human incisors were instrumented with the ProTaper System up to F2 instrument, irrigated with 2.5% NaOCl followed by 17% EDTA and filled with a CH intracanal dressing. After 7 days, the CH dressing was removed using 4 techniques: NiTi rotary instrument size 25, 0.06 taper (K3 Endo) and irrigation with 17% EDTA (Group 1), NiTi rotary F1 instrument (ProTaper) and irrigation with 17% EDTA (Group 2), NiTi rotary instrument size 25, 0.06 taper and irrigation with 2.5% NaOCl (Group 3) and NiTi rotary F1 instrument and irrigation with 2.5% NaOCl (Group 4). Two roots without intracanal dressing were used as negative controls. Teeth were evaluated by scanning electron microscopy, in the cervical and apical canal thirds. None of the techniques removed the CH dressing completely. In the apical and cervical thirds, F1 instrument was better than instrument size 25, 0.06 taper in removing CH residues (p<0.05), regardless of the final irrigating solution. No difference was found between the irrigating solutions in the groups of F1 instrument and of instrument size 25, 0.06 taper (p>0.05). The negative controls had no CH residues on the dentin walls. In conclusion, the ProTaper F1 instrument was better than K3 Endo instrument size 25, 0.06 taper in the removal of CH intracanal medication, regardless of irrigating solution used.     

Suitability of controlled release delivery system for root canal disinfection

Abstract The purpose of the present study was to assess the bacteriologic status of the root canal after disinfection with a quaternary ammonium compound in a controlled release system. Root canal infection was induced in 57 single root teeth in dogs. The canals were then instrumented under aseptic conditions and irrigated with sodium hypochlorite and sterile saline. After the instrumentation, 10 canals were treated with the quaternary ammonium compound in the controlled release system, 9 canals with the quaternary ammonium compound on a cotton pellet, 10 canals with formocresol, 10 canals with a paste of calcium hydroxide. In 18 canals, no intracanal medicament was used. Bacteriologic samples were taken after 14 days using an anaerobic technique. The results indicated that the quaternary ammonium compound in the controlled release system was as effective as formocresol and calcium hydroxide in rendering the root canal free of bacteria. The advantages of an antiseptic with a long-lasting effect for the elimination of bacteria from the root canal and for the prevention of culture reversals were stressed.     

不同根管冲洗方式对粪肠球菌生物膜清除效果评价

目的 比较不同根管冲洗方式对粪肠球菌感染根管预备、冲洗的清除效果,评价不同根管冲洗液残余药量的抗菌效果,为临床上选择根管冲洗方法提供参考。方法 将32颗离体牙（前磨牙、单根管）消毒,接种粪肠球菌60 d,随机分为4组（第1组：生理盐水;第2组：生理盐水+超声1 min;第3组：1%NaOCl;第4组：1%NaOCl+超声1 min）,使用ProTaper器械按照冠向下法进行根管预备,并在预备冲洗前及预备至F2进行冲洗后分别取样、计数,进行统计学分析。将预备好的离体牙再次消毒,随机分为2组,分别浸泡生理盐水和1%NaOCl;浸泡30 min后取出,置于接种粪肠球菌标准菌株（ATCC33186）的培养液内,分别在培养2、6、24、48 h时取样、计数。采用SPSS19.0软件包对数据进行统计学分析。结果 4组在预备至F2冲洗结束后,根管中的细菌数量均不同程度降低,其中,使用1% NaOCl结合超声冲洗1 min,几乎可完全去除根管内的细菌。经1% NaOCl浸泡的牙根样本内的细菌,在培养48 h时后总量少于生理盐水。结论 1%NaOCl是有效的根管冲洗液,用于根管化学预备后的残余液体,也可发挥有效的抗菌效果。联合使用超声器械,可以使其抗菌效果最大化。     

Radiographic evaluation of periradicular repair after endodontic treatment of dog's teeth with induced periradicular periodontitis

Eighty-four root canals of premolars from six dogs were left open for 7 days, and then sealed and followed for 45 days until periradicular periodontitis developed. The root canals were then treated endodontically using 5.25% sodium hypochlorite as the irrigating solution. After instrumentation, all root canals were filled with a calcium hydroxide-based antibacterial dressing (Calen PMCC or Calasept) that was left in place for 30 days. After this period the root canals were filled with gutta-percha cones and a root canal sealer (Sealapex or AH Plus)--group I: Calen PMCC + Sealapex; group II: Calasept + Sealapex; group III: Calen PMCC + AH Plus; and group IV: Calasept + AH Plus. Periapical radiographs of the teeth were made after root canal filling and after 90, 180, 270, and 360 days. Radiographic images were digitalized by scanning, and the Mocha program was used to measure the periapical lesions. Analysis showed that the lesions of groups I to III were statistically similar reduction in size, whereas group IV had a smaller reduction in lesion size (p < 0.05).     

Clinical efficiency of 2% chlorhexidine gel in reducing intracanal bacteria

This study evaluated the clinical efficacy of 2% chlorhexidine (CHX) gel on intracanal bacteria reduction during root canal instrumentation. The additional antibacterial effect of an intracanal dressing (Ca[OH](2) mixed with 2% CHX gel) was also assessed. Forty-three patients with apical periodontitis were recruited. Four patients with irreversible pulpitis were included as negative controls. Teeth were instrumented using rotary instruments and 2% CHX gel as the disinfectant. Bacterial samples were taken upon access (S1), after instrumentation (S2), and after 2 weeks of intracanal dressing (S3). Anaerobic culture was performed. Four samples showed no bacteria growth at S1, which were excluded from further analysis. Of the samples cultured positively at S1, 10.3% (4/39) and 8.3% (4/36) sampled bacteria at S2 and S3, respectively. A significant difference in the percentage of positive culture between S1 and S2 (p < 0.001) but not between S2 and S3 (p = 0.692) was found. These results suggest that 2% CHX gel is an effective root canal disinfectant and additional intracanal dressing did not significantly improve the bacteria reduction on the sampled root canals.     

ANTIMICROBIAL ACTIVITY OF SODIUM HYPOCHLORITE ASSOCIATED WITH INTRACANAL MEDICATION FOR Candida albicans AND Enterococcus faecalis INOCULATED IN ROOT CANALS

Objective:

The purpose of this study was to evaluate the action of sodium hypochlorite (NaOCl) associated with an intracanal medication against Candida albicans and Enterococcus faecalis inoculated in root canals.

Material and Methods:

Thirty-six human single-rooted teeth with single root canals were used. The canals were contaminated with C. albicans and E. faecalis for 21 days and were then instrumented with 1% NaOCl. The roots were divided into 3 groups (n=12) according to the intracanal medication applied: calcium hydroxide paste, 2% chlorhexidine (CHX) gel, and 2% CHX gel associated with calcium hydroxide. The following collections were made from the root canals: a) initial sample (IS): 21 days after contamination (control), b) S1: after instrumentation, c) S2: 14 days after intracanal medication placement; S3: 7 days after intracanal medication removal. The results were analyzed statistically by the Kruskal-Wallis test at 5% significance level.

Results and Conclusions:

Both 1% NaOCl irrigation and the intracanal medications were effective in eliminating E. faecalis and C. albicans inoculated in root canals.     

Effect of sodium hypochlorite and five intracanal medications on Candida albicans in root canals

The aim of this study was to evaluate the effect of 1% sodium hypochlorite and five intracanals medications on Candida albicans harvested inside root canals. The contaminated canals were irrigated with sterile saline solution and then treated as follows: (i) filled with Calen paste (calcium hydroxide/ glycol polyethylene paste); (ii) filled with camphorated paramonochloro phenol (CPMC); (iii) filled with 2% iodine-iodate solution; (iv) filled with tricresol formalin; (v) filled with Calen and CPMC pastes; (vi) irrigation with 1% sodium hypochlorite and filled with no intracanal medication; and (vii) no intracanal medication was used. Canal access and the apical foramen were then sealed with Cavit and the roots were stored in a humid chamber at 37 +/- 1 degree C for 14 days. The canals were reinstrumented and irrigated with sterile saline solution. Sterile paper points were used to transfer the root canal contents to test tubes containing sterile saline solution. Part of the suspension was harvested in Sabouraud dextrose agar with chloramphenicol and incubated at 37 +/- 1 degree C for 48 h. CPMC was effective in 100% of the samples followed in decreasing order of effectiveness by calcium hydroxide with CPMC (70% effective), 1% sodium hypochlorite (70% effective) (p < 0.05), tricresol formalin (60% effective), 2% iodine-iodate solution (50% effective), calcium hydroxide paste (30% effective), and saline + no intracanal medication.     

The effectiveness of three instrumentation techniques on the elimination of Enterococcus faecalis from a root canal: an in vitro study

The in vitro reduction of a bacterial population in a root canal by mechanical instrumentation using three techniques was evaluated. Root canals inoculated with a Enterococcus faecalis (E. faecalis) suspension were instrumented using hand Hedstroem files, Giromatic files, and Hero 642 rotary instruments. Irrigation was performed using sterile saline solution. Root canals were sampled before and after instrumentation. After serial dilutions, samples were plated onto Mitis-Salivarius agar and the colony forming units grown were counted. All instruments tested were able to significantly reduce the number of bacterial cells in the root canal, however, the results of this study indicated that Hedstroem files, Giromatic, and Hero 642 techniques were not significantly different in their ability to reduce intracanal bacteria.     

In vitro evaluation of the action of irrigating solutions associated with intracanal medications on Escherichia coli and its endotoxin in root canals

Objective

The purpose of this study was to evaluate the efficacy of auxiliary chemical substances and intracanal medications on Escherichia coli and its endotoxin in root canals.

Material and Methods

Teeth were contaminated with a suspension of E. coli for 14 days and divided into 3 groups according to the auxiliary chemical substance used: G1) 2.5% sodium hypochlorite (NaOCl); G2) 2% chlorhexidine gel (CLX); G3) pyrogen-free solution. After, these groups were subdivided according to the intracanal medication (ICM): A) Calcium hydroxide paste (Calen®), B) polymyxin B, and C) Calcium hydroxide paste+2% CLX gel. For the control group (G4), pyrogen-free saline solution was used without application of intracanal medication. Samples of the root canal content were collected immediately after biomechanical preparation (BMP), at 7 days after BMP, after 14 days of intracanal medication activity, and 7 days after removal of intracanal medication. The following aspects were evaluated for all collections: a) antimicrobial activity; b) quantification of endotoxin by the Limulus Amebocyte Lysate test (LAL). Results were analyzed by the Kruskal-Wallis and Dunn’s tests at 5% significance level.

Results

The 2.5% NaOCl and CLX were able to eliminate E. coli from root canal lumen and reduced the amount of endotoxin compared to saline.

Conclusions

It was concluded that 2.5% NaOCl and CLX were effective in eliminating E. coli. Only the studied intracanal medications were to reduce the amount of endotoxin present in the root canals, regardless of the irrigant used.     

干髓术失败患牙的根管再治疗

目的:通过对干髓术失败患牙进行根管再治疗,探讨此类病例的特点及再治疗方法.方法:选取干髓术失败的磨牙63个,采用小号K锉配合次氯酸钠溶液和EDTA溶液探查根管并清理根管内的感染物质,封入氢氧化钙糊剂1～2周,采用机动镍钛器械Hero642进行根管预备,侧向加压技术充填根管,记录治疗过程中患牙症状的改善程度,根管疏通情况,根管预备和充填的效果.结果:62个患牙的根管疏通成功,治疗过程中症状明显缓解或完全消失,瘘管明显减小或消失,根管预备时无根管偏移、根尖阻塞、台阶等并发症发生,根管形态良好.结论:干髓术失败患牙在根管治疗时强调彻底清除根管内的感染物质,采用次氯酸钠和EDTA溶液清理根管,氢氧化钙消毒根管,机用镍钛器械进行根管预备能取得良好的治疗效果.     

Bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation

Abstract The purpose of this study was to assess the bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation. Root canal infection was induced in 50 single-rooted teeth in young dogs by removing the pulp and filling the canals with dental plaque. After 7 clays the root canals were instrumented under aseptic conditions with conventional hand instruments, a sonic vibratory device or an ultrasonic device. Sterile saline or 2.5% sodium hypochlorite was used as irrigating solution. Following instrumentation a sterile paper point was sealed into the root canals. After 7 d the root canals were reopened under aseptic conditions and the paper points were incubated for the demonstration of bacteria, using pre-reduced thioglycolate culture medium and anaerobic chambers. The results obtained with the different instrumentation techniques and irrigating solutions were compared by means of the Chi-square test. The results indicated that the sonic and ultrasonic devices were not more effective in the elimination of bacteria from the root canal than conventional hand instrumentation. Irrigation with sodium hypochlorite appeared to be more effective than saline in producing bacteria-free root canals; however, this difference was not statistically significant. Thus, it appeared that more than one appointment and the supporting action of an antibacterial medicament between appointments would be necessary to achieve bacteria-free root canals in infected teeth in a predictable manner.     

Periradicular repair after two-visit endodontic treatment using two different intracanal medications compared to single-visit endodontic treatment

The number of appointments necessary to treat infected root canals is one of the most controversial issues in endodontics. This study evaluated, in dogs, the response of the periradicular tissues to the endodontic treatment of infected root canals performed in a single visit or in two visits, using different interappointment dressings. Periradicular lesions were induced by inoculating Enterococcus faecalis in the root canals. After confirming that a periradicular lesion developed, the root canals were treated within one or two visits, using either ozonized oil or calcium hydroxide in camphorated paramonochlorophenol (CMCP) as an intracanal medication. After 6 months, the animals were sacrificed and the specimens were processed for histological and histobacteriological analysis. The root canals treated in a single visit showed a success rate of 46%. When a calcium hydroxide/CMCP-based interappointment intracanal medication was used, 74% of the cases were categorized as success. In cases where ozonized oil was used as the intracanal medication, a success rate of 77% was observed. These results of the present study demonstrated that the two-visit treatment offered a higher success rate compared to one-visit therapy. In addition, ozonized oil may potentially be used as an intracanal medication.     

In vitro evaluation of the effectiveness of irrigants and intracanal medicaments on microorganisms within root canals

AIM: To evaluate in vitro the effectiveness of sodium hypochlorite (NaOCl), chlorhexidine (CHX) and five intracanal medicaments on microorganisms within root canals. METHODOLOGY: Ninety-six human single-rooted extracted teeth were used. After removing the crowns, canal preparation was completed and the external root surfaces were coated with epoxy resin. Following sterilization, the teeth were contaminated with Candida albicans and Enterococcus faecalis, and were incubated at 37 +/- 1 degrees C for 7 days. The teeth were divided according to the irrigant solution or intracanal medicament: group 1, sterile physiologic solution (SPS) and calcium hydroxide (Ca(OH)2) paste; group 2, SPS and camphorated paramonochlorophenol (CPMC); group 3, SPS and tricresol formalin; group 4, SPS and CaOH2 + CPMC paste; group 5, SPS and PMC furacin; group 6, 2.5% NaOCl without intracanal medication; group 7, 2.0% CHX without intracanal medication and group 8, SPS without intracanal medication (control group). Microbiological samples were collected with sterile paper points, and bacterial growth was determined. The data were submitted to the analysis of variance (anova, P = 0.05). RESULTS: For C. albicans, groups 3 and 8 were statistically less effective than groups 1, 2, 4 and 5 (Kruskal-Wallis (K-W) = 65.241; gl = 7; P = 0.001). For E. faecalis, groups 6 and 8 were statistically less effective than groups 1-4 and 7 (K-W = 61.048; gl = 7; P = 0.001). CONCLUSIONS: Ca(OH)2 + CPMC paste was the most effective intracanal medicament for the elimination of the two microorganisms; 2.0% CHX solution was more effective than 2.5% NaOCl against E. faecalis.