Effectiveness of propolis and calcium hydroxide as a short‐term intracanal medicament against Enterococcus faecalis: A laboratory study

The aim of this study was to investigate the antimicrobial activity of propolis‐based intracanal medicament against Enterococcus faecalis using infected dentine models, and to compare its antimicrobial efficacy with that of the non‐setting calcium hydroxide paste when used as a short‐term medication for 1 and 2 days. A total of 50 dentine discs of 7‐mm length was obtained from extracted human teeth. Five dentine discs were kept sterile to serve as a negative control. The remaining 45 were contaminated with E. faecalis and divided into two groups (n = 20) in addition to five discs that served as a positive control. The discs were treated as follow: 20 discs were filled with propolis, while the other 20 discs were filled with non‐setting calcium hydroxide. Microbiological sampling was performed utilising sterile paper point, headstrom file and disc immersion. Results showed that propolis was significantly more effective than non‐setting calcium hydroxide against E. faecalis after short‐term application, which made comparison from this prospect unlevelled. The most effective microbiological sampling technique was abrading the lumen with headstrom file. Propolis is very effective as intracanal medicament in rapidly eliminating E. faecalis ex vivo.     

Microbial analysis of endodontic infections in teeth with post-treatment apical periodontitis before and after medication

This study aimed to determine the intraradicular microbiota of previously root canal-treated teeth with apical periodontitis and to investigate the antibacterial effectiveness of different intracanal medicaments. Sixteen patients with post-treatment apical periodontitis were allocated into two groups according to the intracanal medicament used: calcium hydroxide (CH) and 2% chlorhexidine gluconate gel (CHX) group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation and finally, after intracanal medication (S3) by means of ddPCR. The unpaired t test was used to compare parametric. S3-total bacteria copy number of the CH group was lower than the CHX group (p < 0.05). There was no statistical difference between the CHX- and the CH groups in terms of E.faecalis copy number (p > 0.05). But in terms of total bacteria, CH is better than CHX. Consequently, CH can be used to optimise the antibacterial efficiency of chemomechanical preparation in previously root canal-treated teeth with apical periodontitis.     

Intratubular decontamination ability and physicochemical properties of calcium hydroxide pastes

Objective

This in vitro study compared the penetration, pH, calcium ion release, solubility, and intradentinal decontamination capacity of calcium hydroxide (CH) pastes with different vehicles and additives.

Materials and methods

Infected standard bovine dentine contaminated with Enterococcus faecalis were treated with propolis extract, chlorhexidine, and camphorated paramonochlorophenol (CPMC) loaded in CH paste for the bacterial viability evaluation made by confocal laser scanning microscopy (CLSM) and microbiological culture. Beside this, 50 acrylic teeth were filled with the previously mentioned pastes to evaluate the pH and calcium ion release (pHmeter and atomic absorption spectrophotometer at time intervals of 7, 15, and 30 days) and solubility (micro-computed tomographic imaging before and after 15 days).

Results

After treatment, all samples decreased intra-dentinal contamination, specially, the CH paste with CPMC. There was no statistically significant difference between the groups when evaluating the intra-canal paste penetration. In the pH measurements, CH with distilled water showed the smallest pH values. Regardless the solubility percentage of the pastes, the paste of CH + PG presented the highest values.

Conclusion

The vehicles and additives tested may increase CH antimicrobial effect, but with small differences. In general, all CH pastes tested here were effective in reducing Enterococcus faecalis and were similar in the penetration, pH, calcium ion release, and solubility of calcium hydroxide when compared to distilled water.

Clinical relevance

The use of calcium hydroxide pastes as intracanal medication with an aqueous or viscous vehicle, as propylene glycol, can be useful, since all formulations of the tested pastes resulted in great bacterial reduction inside 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.     

氢氧化钙应用于根管封药的临床研究

目的：观察氢氧化钙甘油糊剂用于根管封药的临床疗效。方法：选择244例慢性根尖周炎病例，随机分观察组（氢氧化钙甘油糊剂组）124例、 对照组（甲醛甲酚组）120例，观察封药一周后的临床疗效和细菌培养结果。结果：两组的临床效果有显著差异（P＜0．01）。Ca(OH2)组67．7％一次封药后即可行根管充填，FC组为40％，Ca(OH2)组治疗期间未产生疼痛，FC组则有8．3％产生疼痛，平均封药次数Ca(OH2)组1．38次，FC组1．76次，细菌培养结果与此呈正相关。结论：氢氧化钙甘油糊剂在杀灭微生物、减少治疗期间疼痛和 减低对根尖周组织和刺激性方面效果优良。     

Effect of different final irrigation agitation techniques on root canal dentin tubule penetration of nanoparticle calcium hydroxide dressing

This study is aimed to assess the efficacy of different final irrigation agitation techniques on dentin tubule penetration of nanoparticle calcium hydroxide (NCH) dressing. Ninety-six extracted upper incisors were shaped up to #40file. Then, Four experimental groups were formed according to the final irrigation procedure: conventional needle irrigation (CNI), manual dynamic agitation (MDA), sonic agitation (SA) and ultrasonic irrigant agitation (UIA). According to the intracanal drug used, these groups were divided into two subgroups: calcium hydroxide (CH) and NCH. Prepared CH preparations were labelled with Rhodamine B, and CH or NCH were placed in root canals. In the UIA group, both CH and NCH had the highest penetration depth and percentage compared to the other groups (p < 0.05). The penetration depth and percentage of NCH in the UIA and SA groups were significantly higher than in the CH groups (p < 0.05). UIA is more effective than other groups in increasing dentinal tubule penetration of CH and NCH.     

Effect of a calcium hydroxide/chlorhexidine paste as intracanal dressing in human primary teeth with necrotic pulp against Porphyromonas gingivalis and Enterococcus faecalis

International Journal of Paediatric Dentistry 2012; 22: 116–124 Background. Intracanal medication is important for endodontic treatment success as it eliminates microorganisms that persist after biomechanical preparation. Aim. To evaluate the effect of two intracanal medications against Porphyromonas gingivalis and Enterococcus faecalis in the root canals of human primary teeth with necrotic pulp with and without furcal/periapical lesion, using quantitative real‐time polymerase chain reaction (qRT‐PCR). Design. Thirty‐two teeth with necrotic pulp were used. Twelve teeth did not present lesion, and 20 teeth presented radiographically visible furca/periapical lesion. Microbiological samples were collected after coronal access and biomechanical preparation. The teeth were medicated with calcium hydroxide pastes prepared with either polyethylene glycol or chlorhexidine. After 30 days, the medication was removed and a third collection was performed. Microbiological samples were processed using qRT‐PCR. Data were analysed by Wilcoxon and Mann–Whitney tests (α = 0.05). Results. There was no significant difference in the microbiota present in the primary teeth with and without furcal/periapical lesion. Biomechanical preparation was effective in reducing the number of microorganisms (P < 0.05). The intracanal medications had similar antibacterial activity. Conclusion. The association of chlorhexidine with calcium hydroxide did not increase the antibacterial activity of the intracanal medication in the treatment of primary teeth with necrotic pulp with and without furcal/periapical lesion.     

金栀含漱液冲洗消毒根管的临床疗效观察

目的：评价金栀含漱液冲洗消毒根管的临床疗效。方法：选择需作根管治疗术患牙240个，随机分为两组，试验组和对照组各120个。试验组采用金栀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15g／L氯亚明液冲洗根管，氢氧化钙药捻消毒根管。分别对患牙根管治疗的临床疗效、疗程及根管预备封药前后临床症状的变化进行评价。结果：金栀含漱液组与氢氧化钙组冲洗消毒根管的临床疗效无统计学差异。结论：金栀含漱液用于根管冲洗消毒有良好的临床疗效。     

Analysis of the reaction of subcutaneous tissues in rats and the antimicrobial activity of calcium hydroxide paste used in association with different substances

The aim of this study was to evaluate the subcutaneous tissue response in rats and the antimicrobial activity of intracanal calcium hydroxide dressings mixed with different substances against E. faecalis. Fifty four rats were divided into three experimental groups according to the vehicle in the calcium hydroxide treatment: 0.4% chlorohexidine in propylene glycol (PG), Casearia sylvestris Sw in PG and calcium hydroxide+PG (control group). The pastes were placed into polyethylene tubes and implanted into the subcutaneous tissue. After 7, 14 and 30 days, the samples were processed and histologically evaluated (hematoxylin and eosin). The tissue surface in contact with the material was analyzed, and the quantitative analysis determined the volume density occupied by the inflammatory infiltrate (giant cells, polymorphonuclear cells and mononuclear cells), fibroblasts, collagen fibers and blood vessels. For the antimicrobial analysis, 20 dentin blocks infected with E. faecalis were treated with calcium hydroxide pastes in different vehicles; 0.4% chlorhexidine in PG, PG, extract from Casearia sylvestris Sw in PG and a positive control (infection and without medication) for 7 days. The efficiency of the pastes was evaluated by the live/dead technique and confocal microscopy. The results showed that 0.4% chlorhexidine induced a higher inflammatory response than the other groups. The Casearia sylvestris Sw extract showed satisfactory results in relation to the intensity of the inflammatory response. In the microbiological test, there were no statistical differences between the evaluated intracanal dressings and the percentage of bacterial viability was between 33 and 42%. The control group showed an 86% viability. Antimicrobial components such as chlorhexidine or Casearia sylvestris Sw did not improve the antimicrobial activity against E. faecalis in comparison to the calcium hydroxide+PG treatment. In addition, the incorporation of chlorhexidine in the calcium hydroxide paste promoted the highest inflammatory response.     

In vitro effects of calcium hydroxide and polymyxin B on endotoxins in root canals

OBJECTIVES: To evaluate the effects of intracanal medicaments on endotoxins in root canals. METHODS: Seventy-five freshly extracted maxillary incisors were used in this study. The crowns of teeth were sectioned near the CEJ in order to standardize the root length to 14 mm. The root canals were instrumented to an apical size #50 file and irrigated with 1% sodium hypochlorite solution and sterilized with 60Co gamma irradiation. Standardized suspension containing Escherichia coli endotoxin was inoculated into the 60 root canals. The specimens were randomly assigned to 5 groups (n=15), according to the intracanal medicament used: (G1) calcium hydroxide; (G2) polymyxin B; (G3) combination neomycin-polymyxin B-hydrocortisone; (G4) positive control (no intracanal medicament); (G5) negative control (no endotoxin and no intracanal medicament). After 7 days, the detoxification of endotoxin was evaluated by Limulus lysate assay and antibody production in B-lymphocytes culture. RESULTS: Groups 1, 2 and 5 presented the best results by Limulus lysate and were significantly different to groups 3 and 4 (p<0.05). Stimulation of antibodies production in cell culture by groups 1 and 6 was smaller and statistically different than groups 2, 3, 4 and 5 (p<0.05). Groups 2 and 5 induced a small increase in the antibodies production in relation to the groups 1 and 6. Groups 3 and 4 induced a significant increase of antibodies production (p<0.05). CONCLUSIONS: The calcium hydroxide and polymyxin B intracanal medicaments detoxified endotoxin in root canals and altered the properties of LPS to stimulate the antibody production by B-lymphocytes. The combination neomycin-polymyxin B-hydrocortisone did not detoxified endotoxin.     

氢氧化钙预防根管治疗术后疼痛的临床观察

目的评价氢氧化钙作为根管内药物预防根管治疗术后疼痛的效果。方法选择90颗牙髓坏死的前磨牙,将其随机分为A、B、C组,每组30颗牙。A组患牙1次完成根管治疗;B组患牙2次完成根管治疗,但约诊期间根管内不封任何药物;C组患牙2次完成根管治疗,但约诊期间根管内封Ca(OH)2糊剂。采用改良10点视觉模拟量表对患者根管治疗后疼痛的严重程度进行评价,比较3组患者根管治疗后的疼痛水平。结果A组与B组、B组与C组患者根管治疗术后疼痛的差异有统计学意义(P<0.05),A组与C组患者根管治疗术后疼痛的差异无统计学意义(P>0.05)。结论氢氧化钙作为根管内封药可有效预防根管充填后疼痛的发生。     

Vitapex治疗根尖囊肿的临床疗效分析

目的:比较Vitapex糊剂作为根管消毒药物治疗较大根尖囊肿的临床疗效。方法:将临床诊断为根尖囊肿的52例患牙随机分为两组,每组26例,以氢氧化钙糊剂为对照组,根管内封氢氧化钙1周后即AH-plus糊剂和牙胶尖充填,6个月和12个月复诊。Vitapex糊剂为实验组,根管内封Vitapex 6个月,复诊时再以AH-plus糊剂牙胶尖充填,继续观察6个月,即12个月时复诊。比较6个月复诊及12个月复诊时实验组及对照组的治疗效果。结果:6个月复诊时,氢氧化钙组的成功率为73.1%,Vitapex组的成功率为76.9%。两组间无显著性差异。12个月复诊时,氢氧化钙组的成功率为69.2%,Vitapex组的成功率为92.3%,两组间有显著性差异。结论:根尖囊肿采取Vitapex多次封药,可以促进根尖病变愈合,提高疗效。     

Effect of 2% chlorhexidine gel as an intracanal medication on the apical seal of the root-canal system

The purpose of this study was to determine what effect intracanal medications might have on the apical seal of the root-canal system. Forty-two teeth were cleaned and shaped in a crown-down manner to a size #50 K-file. The teeth were divided into three groups: (A) immediate obturation; (B) intracanal placement of calcium hydroxide placed for 14 days; and (C) 2% chlorhexidine gel placed for 14 days. After 14 days, these materials were removed using copious irrigation and obturation was completed on groups B and C. Obturation was performed using the continuous wave of condensation technique using AH Plus sealer in all groups. Leakage was evaluated 60 days after obturation by using a fluid-filtration device. Using the one-way ANOVA test, there was no statistically significant difference in leakage between the three groups. Under the conditions of this study, 2% chlorhexidine gel and calcium hydroxide paste did not adversely affect the apical seal of the root-canal system.     

Comparative evaluation of propolis and triantibiotic mixture as an intracanal medicament against Enterococcus faecalis

Introduction

The aim of this study was to evaluate and compare the antimicrobial activity of calcium hydroxide, triantibiotic mixture (TAM), and an ethanol extract of propolis as intracanal medicaments on Enterococcus faecalis-infected root canals.

Methods

One hundred twenty extracted intact human permanent incisors were decoronated, and chemomechanical preparation of the root canal was performed. After sterilization of the samples, they were inoculated with pure culture of E. faecalis and incubated. After incubation, colony-forming units were recorded before medication. Then, samples were divided randomly into five groups (n = 24). Each group was then exposed to various intracanal medicaments, namely calcium hydroxide (group 1), TAM (group 2), propolis (group 3), ethanol (group 4), and saline as the control group (group V). The antibacterial effectiveness of the different intracanal medicament was recorded by determining the percentage reduction in colony counts (%RCC) at the end of days 1, 2, and 7. The data were statistically analyzed using one-way analysis of variance and Tukey Honestly Significant Difference (HSD) post hoc test.

Results

The %RCC was highest for propolis showing 100% reduction on day 2 followed by TAM showing 82.5%, 92.2%, and 98.4% of reduction on days 1, 2, and 3, respectively. Calcium hydroxide showed a gradual increase in antibacterial activity with a maximum of 59.4% on day 7.

Conclusions

Propolis was more effective than TAM against E. faecalis at a 2-day time period, and both were equally effective at 7 days.     

Effect of a Residual Biofilm on Release of Transforming Growth Factor β1 from Dentin

IntroductionSeveral studies have reported regeneration of the pulp-dentin complex when treating noninfected root canal systems. However, current protocols applied to infected root canal systems are much less predictable for the formation of dentin. Converging lines of evidence implicate residual biofilm as an important factor for these variable histologic outcomes. Here we studied the effect of a residual polymicrobial biofilm on the release of transforming growth factor beta 1 (TGF-β1) from dentin. We hypothesized that the presence of bacterial biofilm attenuates the release of bioactive molecules from dentin.MethodsUsing bacteria commonly found in infected immature teeth, we developed a multispecies biofilm in an organotypic root canal model. Root segments were then subjected to various irrigation or intracanal medicament protocols. Subsequently, the release of TGF-β1 from dentin was measured using the enzyme-linked immunosorbent assay.ResultsOur data show that sterile root segments released greater amounts of TGF-β1 when conditioned with 17% EDTA alone (P < .001) or with the combination of 1.5% sodium hypochlorite and 17% EDTA (P < .05) compared with root segments infected with the multispecies biofilm. Similar results were also observed with the intracanal medicament protocol. Sterile root segments medicated with various concentrations of triple antibiotic paste and full-strength calcium hydroxide released greater amounts of TGF-β1 when compared with their infected counterparts.ConclusionsThis is the first study to report the detrimental effects of a residual biofilm on dentin conditioning and, therefore, the release of growth factors critical for regenerative procedures.     

Calcium ion diffusion from calcium hydroxide-containing materials in endodontically-treated teeth: An in vitro study

The aim of this in vitro study was to determine the amount and duration of diffusion of calcium ions from both a calcium hydroxide-containing root canal sealer and an intracanal medicament, through the apical foramen and the dentinal tubules of endodontically-treated teeth. The root canals of 88 freshly extracted single-rooted teeth were prepared using the modified double flared, balanced force technique with patency filing. The teeth were divided into four test groups of 20 teeth each and a control group of eight teeth. One group was dressed with a non-setting calcium hydroxide while the other was obturated using cold lateral condensation of gutta-percha with a calcium hydroxide-containing sealer. An artificial root defect was created in the apical third of the root of the teeth in the other two groups and the root canals were either dressed or obturated in the same way as the first two groups. All groups were incubated at 37°C and were sampled for calcium diffusion after 1, 2 and 3 days and 1,2,3,4 and 8 weeks. There was statistically significantly more calcium diffusion with the non-setting groups compared with the sealer groups (P < 0.05). There was more calcium ion diffusion from teeth with a patent apical foramen than those with an artificial resorptive root defect (P< 0.05).     

Evaluation of the Antibacterial Efficacy of Silver Nanoparticles against Enterococcus faecalis Biofilm

Introduction

The purpose of this study was to evaluate the antibacterial efficacy of silver nanoparticles (AgNPs) as an irrigant or medicament against Enterococcus faecalis biofilms formed on root dentin.

Methods

Dentin sections were inoculated with E. faecalis for 4 weeks to establish a standard monospecies biofilm model. These biofilms were tested in 2 stages. In stage 1, the biofilms were irrigated with 0.1% AgNP solution, 2% sodium hypochlorite, and sterile saline for 2 minutes, respectively. In stage 2, the biofilms were treated with AgNP gel (0.02% and 0.01%) and calcium hydroxide for 7 days. The ultrastructure of one half of the specimens from each group was evaluated by using scanning electron microscopy, whereas the structure and distribution of viable bacteria of the other half of the specimens were assessed with confocal laser scanning microscopy combined with viability staining.

Results

Syringe irrigation with 0.1% AgNP solution did not disrupt the biofilm structure, and the proportion of viable bacteria in the biofilm structures was not different from that of the saline group (P > .05) but was less than that of the control group (P < .05). The biofilms treated with 0.02% AgNP gel as medicament significantly disrupted the structural integrity of the biofilm and resulted in the least number of post-treatment residual viable E. faecalis cells compared with 0.01% AgNP gel and calcium hydroxide groups (P < .05).

Conclusions

The findings from this study suggested that the antibiofilm efficacy of AgNPs depends on the mode of application. AgNPs as a medicament and not as an irrigant showed potential to eliminate residual bacterial biofilms during root canal disinfection.     

Efficacy of a combined nanoparticulate/calcium hydroxide root canal medication on elimination of Enterococcus faecalis

The purpose of this study was to evaluate the efficacy of Ca(OH)₂ with or without a silver nanoparticle suspension to eliminate Enterococcus faecalis from root canals. A total of 66 extracted human single‐rooted teeth contaminated with E. faecalis were treated with 10% Ca(OH)₂ alone, Ca(OH)₂ with nanosilver or sterile water (as a negative control). Samples were obtained with paper points and Gates‐Glidden burs at 1 and 7 days after root canal preparation and the number of colony‐forming units (CFU) was determined. The number of CFUs observed after dressing with Ca(OH)₂ + nanosilver was significantly less than the number observed with Ca(OH)₂ alone after 1 or 7 days (P < 0.001, P < 0.001). No differences in antimicrobial properties were observed between the two time points in the Ca(OH)₂ + nanosilver group (P > 0.05). Higher antimicrobial efficacy was observed in the Ca(OH)₂ group after 7 days than 1 day (P < 0.001). This study highlighted the potential advantage of using a mixture of Ca(OH)₂ and nanosilver for intracanal medicament.     

Effect of the quorum‐sensing luxS gene on biofilm formation by Enterococcus faecalis

Enterococcus faecalis is the species of bacterium most frequently isolated from the root canals of teeth that exhibit chronic apical periodontitis refractory to endodontic treatment. In this study, we evaluated the effect of the S‐ribosylhomocysteine lyase (luxS) quorum‐sensing gene on E. faecalis biofilm formation by constructing a knockout mutant. The biofilms formed by both E. faecalis and its luxS mutant strain were evaluated using the MTT method. Important parameters that influence biofilm formation, including cell‐surface hydrophobicity and the nutrient content of the growth medium, were also studied. Biofilm structures were observed using confocal laser scanning microscopy (CLSM), and expression of biofilm‐related genes was investigated using RT‐PCR. The results showed that the luxS gene can affect biofilm formation, whereas it does not affect the bacterial growth rate. Deletion of the luxS gene also increased cell‐surface hydrophobicity. Biofilm formation was accelerated by the addition of increasing concentrations of glucose. The CLSM images revealed that the luxS mutant strain tends to aggregate into distinct clusters and relatively dense structures, whereas the wild‐type strain appears confluent and more evenly distributed. All genes examined were up‐regulated in the biofilms formed by the luxS mutant strain. The quorum‐sensing luxS gene can affect E. faecalis biofilm formation.