Assessment of depth of penetration and antibiofilm properties of Boswellia sacra compared with calcium hydroxide intracanal medicament (in vitro study)

Successful endodontic treatment requires advanced materials to eliminate biofilm This study aims to assess the penetration depth and the effectiveness of Boswellia sacra as a novel intracanal medicament compared with calcium hydroxide against Enterococcus faecalis biofilm. 60 single-rooted teeth were decoronated, prepared and sterilised. Fifty teeth were contaminated with a culture of E. faecalis (ATCC 19433) for 21 days. Two teeth were used to confirm the biofilm using scanning electron microscope. For colony-forming unit (CFU), 40 samples were divided into one control group (calcium hydroxide) and the other experimental group (B. sacra). Each group was divided into two subgroups to be tested at 3 and 7 days. The minimum inhibitory concentration (MIC) of B. sacra was determined, and the B. sacra's ethanolic extract medicament was prepared. Eight discs divided into groups similar to CFU were used to evaluate live/dead bacteria using confocal laser scanning microscopy (CLSM). Ten teeth were selected for penetration depth using CLSM. The intracanal medicaments were mixed with 0.1% rhodamine B. were inserted into the root canals 0.2 slices were dissected and viewed under CLSM. The MIC of B. sacra was 1.25 mg/ml. The CFU evaluation proved that B. sacra are more effective than calcium hydroxide in the 3 days groups. However, it was statistically insignificant compared with calcium hydroxide after 7 days. The depth of penetration of B. sacra exceeds that of calcium hydroxide. B. sacra is an effective intracanal medicament.     

Outcome of Regenerative Endodontic Procedures in Nonvital Immature Permanent Teeth Using 2 Intracanal Medications: A Prospective Randomized Clinical Study

IntroductionThis randomized clinical trial aimed to assess and compare the long-term clinical and radiographic outcomes of regenerative endodontic procedures (REPs) in treating nonvital immature permanent teeth using 2 intracanal medicaments.MethodsForty-five patients yielding a total of 50 anterior and posterior nonvital immature teeth were randomly divided into 2 groups. REPs using either nonsetting calcium hydroxide (Ca[OH]₂) (n = 25) or modified triple antibiotic paste (TAP) (n = 25) as intracanal medicaments were performed. NeoMTA Plus (Avalon Biomed Inc) was applied for coronal sealing. Cases were followed up clinically and radiographically for 36 months. The survival rate, success rate, and clinical outcome measures were analyzed. Preoperative and recall radiographs were evaluated for dimensional changes in root length, dentin thickness, apical diameter, and periapical radiolucency.ResultsAt the 36-month follow-up, the success and survival rates were 81.6% and 100%, respectively, in which 79.4% of cases showed complete resolution of periapical radiolucency with no significant difference between the nonsetting Ca(OH)₂ and modified TAP groups (P > .050). The cumulative changes in root length, root dentin thickness, and apical diameter throughout the study period were observed in 47.9%, 77.1%, and 89.6% of cases, respectively, with no significant differences between groups (P ≥ .39). Intracanal calcifications were detected in 60% of cases with no significant difference between groups (P = .77).ConclusionsREPs, using either nonsetting Ca(OH)₂ or modified TAP as the intracanal medicament, exhibited high success and survival rates over a follow-up period of 36 months with equally favorable clinical and radiographic outcome data.     

Association between Intracanal Medicament Radiopacity and Streak Artifact Production Using Cone-beam Computed Tomography: A Laboratory Study

IntroductionThis study aimed to calculate the correlation between the radiopacity levels of various intracanal medicaments and radiolucent streak formation using cone-beam computed tomography (CBCT).MethodsSeven commercially-available intracanal medicaments were tested, which contained different amounts of radiopacifier [Consepsis, Ca(OH)₂, UltraCal XS, Calmix, Odontopaste, Odontocide, and Diapex Plus]. Their radiopacity levels were measured according to the International Organization for Standardization 13116 testing standards (mmAl). Subsequently, the medicaments were placed in 3 canals of radiopaque artificial printed maxillary molars (n = 15 roots per medicament), leaving the second mesiobuccal canal empty. CBCT imaging was carried out using an Orthophos SL 3-dimensional scanner under recommended manufacturer exposure settings. Radiopaque streak formation was assessed by a calibrated examiner using a previously published grading system (0–3). The Kruskal-Wallis and Mann-Whitney U tests with and without Bonferroni correction were used to compare radiopacity levels and radiopaque streak scores for the medicaments. Their relationship was assessed using the Pearson correlation coefficient. The level of significance was set as (α = 0.05).ResultsDiapex plus presented with the highest radiopacity levels (4.98 ± 0.01) and radiopaque streak scores [middle third (2.8 ± 0.18); apical third (2.73 ± 0.43)]; which was similar to UltraCal XS's radiopaque streak scores [middle third (2.8 ± 0.92); apical third (2.73 ± 0.77)]. Consepsis had the lowest radiopacity levels (0.12 ± 0.05), followed by Odontocide (0.60 ± 0.05). Consepsis and Ca(OH)₂ were scored 0 for artifacts in all roots at all levels. A high positive correlation (R = 0.95) was found between radiopacity and streak formation.ConclusionsThe radiopacity of intracanal medicaments varies and strongly correlates with the formation of radiolucent streak artifacts during CBCT.     

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.     

Characterisation of the efficacy of endodontic medications using a three‐dimensional fluorescent tooth model: An ex vivo study

The purpose of this study was to establish a three‐dimensional fluorescent tooth model to investigate bacterial viability against intra‐canal medicaments across the thickness and surface of root dentine. Dental microbial biofilms (Enterococcus faecalis and Streptococcus mutans) were established on the external root surface and bacterial kill was monitored over time against intra‐canal medicament (Ca(OH)₂) using fluorescent microscopy in conjunction with BacLight SYTO9 and propidium iodide stains. An Olympus digital camera fitted to SZX16 fluorescent microscope captured images of bacterial cells in biofilms on the external root surface. Viability of biofilm was measured by calculating the total pixel area of green (viable bacteria) and red (non‐viable bacteria) for each image using ImageJ® software. All data generated were assessed for normality and then analysed using a Mann–Whitney t‐test. The viability of S. mutans biofilm following Ca(OH)₂ treatment showed a significant decline compared with the untreated group (P = 0.0418). No significant difference was seen for E. faecalis biofilm between the Ca(OH)₂ and untreated groups indicating Ca(OH)₂ medicament is ineffective against E. faecalis biofilm. This novel three‐dimensional fluorescent biofilm model provides a new clinically relevant tool for testing of medicaments against dental biofilms.     

Combined Effect of a Mixture of Silver Nanoparticles and Calcium Hydroxide against Enterococcus faecalis Biofilm

IntroductionThe aim of this study was to evaluate the antibiofilm effectiveness of calcium hydroxide (Ca[OH]₂) mixed with 0.02% silver nanoparticles (AgNPs) in comparison with 1 mg/mL triple antibiotic paste (TAP), Ca(OH)₂, and 0.02% AgNPs against Enterococcus faecalis using confocal laser scanning microscopy.MethodsNinety dentin disks were prepared, sterilized, and inoculated with E. faecalis to establish a 3-week-old biofilm model. The samples received 1 mg/mL TAP, a mixture of Ca(OH)₂ + 0.02% AgNPs, Ca(OH)₂, or 0.02% AgNPs (n = 20/group). Specimens in each group were equally subdivided into 2 groups and incubated for 2 and 4 weeks. Untreated dentin disks (n = 10) were exposed to sterile saline solution and acted as a positive control. Sterile dentin disks (n = 10) were incubated anaerobically in brain-heart infusion broth and served as a negative control. At the end of each observation period, the specimens were stained with LIVE/DEAD BacLight dye (Molecular Probes, Eugene, OR) and analyzed with confocal laser scanning microscopy to determine the proportion of dead cells in the biofilm. Statistical analysis was performed using the generalized linear model repeated measure and Tukey tests (P < .05).ResultsA significantly greater proportion of dead cells was observed in the samples treated with 1 mg/mL TAP (90.39% and 99.41%) and a mixture of Ca(OH)₂ + AgNPs (90.85% and 98.49%) than those in the samples treated with Ca(OH)₂ (76.14% and 91.71%) and AgNPs (62.83% and 88.07%) at 2 and 4 weeks, respectively. A significant difference in the antibiofilm effectiveness was observed among the groups (P < .05), except for 1 mg/mL TAP and the mixture of Ca(OH)₂ + AgNPs (P > .05). All medicaments showed a significant difference in antibiofilm efficacy at the 2 time points.ConclusionsThe mixture of Ca(OH)₂ + AgNPs showed a high antibiofilm effect and was not significantly different from 1 mg/mL TAP. Furthermore, long-term contact between intracanal medicaments and bacterial cells achieved significant antibiofilm efficacy.     

Removal efficacy of various calcium hydroxide/chlorhexidine medicaments from the root canal

Aim To compare the efficiency of removing calcium hydroxide [Ca(OH)₂]/chlorhexidine (CHX) (gel), Ca(OH)₂/CHX (solution) and Ca(OH)₂/saline pastes with the use of instrumentation and irrigation with sodium hypochlorite and ethylene diamine tetraacetic acid (EDTA) solutions. Moreover the role of the patency file in the cleanliness of the apical third of the root canal was evaluated. Methodology Sixty‐four human single‐rooted teeth with straight canals were used. Root canal preparation was performed with a stepback technique using Hedström (H) files. Teeth were randomly assigned to three groups and subsequently filled with one of the pastes: Ca(OH)₂/CHX (gel), Ca(OH)₂/CHX (solution) and Ca(OH)₂/saline paste. The medicaments were removed 10 days later using instrumentation and irrigation with 1% sodium hypochlorite and 17% EDTA, with or without obtaining patency of the apical foramen with a size 10 H‐file. The crowns were removed at the cemento‐enamel junction and the roots were grooved longitudinally and split into halves. Images of all halves were acquired with the use of a flatbed scanner. A scoring system of 1 to 4 was used to assess the amount of residue on the cervical, middle and apical third of the canal. Data were subjected to statistical analysis using Kruskal–Wallis and Mann–Whitney tests, with Bonferroni correction, at 95% confidence level (P < 0.05). Results Remnants of medicament were found in all experimental teeth regardless of the experimental material used and the use of the patency file. When examining the root canal as a whole, Ca(OH)₂/CHX (gel) paste was associated with significantly larger amount of residue, whereas the Ca(OH)₂/CHX (solution) paste was associated with less amount (P < 0.05) than the other two medicaments with or without the use of a patency file. Conclusions None of the techniques used in this study removed the inter‐appointment root canal medicaments effectively; the use of the patency file facilitated removal of more of the medicament in the apical third of those straight canals.     

Effect of Different Final Irrigation Methods on the Removal of Calcium Hydroxide from an Artificial Standardized Groove in the Apical Third of Root Canals

Introduction

The aim of this study was to compare the efficacy of conventional syringe, ultrasonic, EndoVac (Discus Dental, Culver City, CA), and Self-Adjusting File (SAF) (Re-Dent-Nova, Ra'nana, Israel) irrigation systems in removing calcium hydroxide (Ca[OH]₂) from simulated root canal irregularities.

Methods

The root canals of 88 extracted single-rooted teeth were prepared using ProTaper rotary instruments (Dentsply Maillefer, Ballagiues, Switzerland) up to size F4. The roots were split longitudinally, and a standardized groove was prepared in the apical part of 1 segment. The root halves were reassembled, and Ca(OH)₂ medicament was placed into the root canals using a Lentulo spiral. The roots were randomly divided into 4 experimental groups and 2 control groups according to the different irrigation systems used: conventional syringe irrigation, continuous passive ultrasonic irrigation (PUI), EndoVac irrigation, and SAF irrigation. Each group was then divided into 2 subgroups (n = 10) according to the irrigation protocol: subgroup 1: 10 mL 2.5% NaOCl and subgroup 2: 10 mL 17% EDTA + 10 mL 2.5% NaOCl. The amount of remaining medicament was evaluated under a stereomicroscope at 30× magnification using a 4-grade scoring system. The influences of the different Ca(OH)₂ medicament removal methods and irrigation protocols were statistically evaluated using 2-way analysis of variance and Tukey post hoc tests.

Results

In the NaOCl-irrigated groups, PUI removed significantly more Ca(OH)₂ medicament than the other techniques (P < .05). There was no significant difference among the other groups (P > .05). In the EDTA/NaOCl-irrigated groups, the SAF and PUI removed significantly more Ca(OH)₂ than the other techniques (P < .05).

Conclusions

The use of the SAF system with the combination of EDTA and NaOCl enhanced Ca(OH)₂ removal when compared with the use of only NaOCl irrigation with the SAF. Continuous PUI and SAF were more effective than EndoVac, and conventional syringe irrigation in the removal of the Ca(OH)₂ medicament from an artificial standardized groove in the apical part of the root canal.     

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 hydroxide as an intracanal medication for postoperative pain during primary root canal therapy: A systematic review and meta-analysis with trial sequential analysis of randomised controlled trials

ObjectiveTo evaluate the effectiveness of CH as an intracanal medicament compared to no dressing and / or other intracanal medicaments to control postoperative pain in patients with apical periodontitis requiring primary root canal therapy.Materials and MethodsWe conducted electronic searches in PubMed, EMBASE, Scopus and Cochrane Library, Open Gray, and Google Scholar.A structured Population-Intervention-Comparison-Outcome of the review was as follows: Population: adults who presented with apical periodontitis requiring primary root canal therapy; Intervention: CH intracanal medicament; Comparison: no dressing/other intracanal medicaments; Main Outcome: Postoperative pain.We assessed the risk of bias using Cochrane criteria. Our outcome measures were intensity of pain on a validated scale reported as mean and standard deviation. We performed meta-analysis using the random-effects model. We rated the quality of evidence using GRADE.ResultsWe included 18 studies with 1192 participants. The overall risk of bias was moderate. We found a significant improvement in postoperative pain at 24 hours in favor of CH over no intracanal medication (4 trials, n = 226: standardised mean difference: -0.71; [95% confidence interval: -1.38, -0.03]; P = .04; I²= 78%; moderate certainty evidence). Ledermix (Lederle Germany) (steroid-antibiotic) and chlorhexidine were significantly more effective than CH for controlling pain at 72 hours postprocedure (low certainty evidence). Silver nanoparticles were more effective than CH at 6 and 24 hours and combinations of CH with dexamethasone or lidocaine HCl were significantly more effective than CH alone at improving postoperative pain.Substantial heterogeneity limits the robustness of findings.ConclusionLimited evidence suggests that CH may be an effective intracanal medicament for controlling interappointment pain. Combination therapies appear to be more effective than using CH alone. Further research assessing the comparative effectiveness of interventions for managing postoperative pain following root canal therapy is warranted.     

Antimicrobial efficacy of a polymeric chlorhexidine release device using in vitro model of Enterococcus faecalis dentinal tubule infection

This study aimed to assess the antimicrobial efficacy of a novel polymeric chlorhexidine-controlled release device as an intracanal medicament. One hundred cylindrical dentin blocks prepared from human single-rooted teeth were inoculated with Enterococcus faecalis for 3 weeks. The intracanal medicaments tested were calcium hydroxide, a polymeric chlorhexidine-controlled release device (PCRD), a polymeric controlled release device without chlorhexidine (CHx), 0.2% CHx solution, and sterile saline. Dentin samples (at 200-mum and 400-mum depths) were collected from the medicated canal lumens after 1 week of medication with sterile LightSpeed files and placed in growth medium. Bacterial growth was assessed spectrophotometrically by analysis of optical density (OD) after 24 hours of incubation. The OD values at both depths were significantly lower in the PCRD group than in the other experimental groups (P < .001). These results indicate that a PCRD can be an effective intracanal medicament against E. faecalis.     

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.     

Efficacy of propolis as an intracanal medicament against Enterococcus faecalis

This study sought to compare the antibacterial efficacy of three commonly used intracanal medicaments with propolis against Enterococcus faecalis. This study utilized 180 freshly extracted single-rooted intact human permanent teeth with a single root canal. After root canal preparations and sterilization, canals were contaminated with E. faecalis and incubated at 37 degrees C (+/- 1.0 degrees C) for seven days. The teeth were divided randomly into six groups. To determine bacterial growth on blood agar, microbiological samples were carried out with sterile paper points to evaluate results at 48 hours and at ten days. All data were analyzed statistically with t-test, Mann Whitney, Kruskal Wallis, and one-way ANOVA tests. This study revealed that propolis had good in vitro antibacterial activity against E. faecalis in the root canals, suggesting that it could be used as an alternative intracanal medicament.     

A Retrospective Evaluation of Radiographic Outcomes in Immature Teeth With Necrotic Root Canal Systems Treated With Regenerative Endodontic Procedures

IntroductionSeveral case reports on endodontic regeneration involving immature permanent teeth have recently been published. These case series have used varying treatments to achieve endodontic regeneration including triple antibiotic paste, Ca(OH)₂, and formocresol. However, no study has analyzed the overall results.MethodsIn this retrospective study, we collected radiographs from 54 published and unpublished endodontic regenerative cases and 40 control cases (20 apexification and 20 nonsurgical root canal treatments) and used a geometrical imaging program, NIH ImageJ with TurboReg plug-in, to minimize potential differences in angulations between the preoperative and recall images and to calculate continued development of root length and dentin wall thickness.ResultsThe comparison to the 2 control groups provided a validation test for this method. Forty-eight of the 54 regenerative cases (89%) had radiographs of sufficiently similar orientation to permit analysis. The results showed regenerative endodontic treatment with triple antibiotic paste (P < .001) and Ca(OH)₂ (P < .001) produced significantly greater increases in root length than either the MTA apexification or NSRCT control groups. The triple antibiotic paste produced significantly greater differences in root wall thickness than either the Ca(OH)₂ or formocresol groups (P < .05 for both). The position of Ca(OH)₂ also influenced the outcome. When Ca(OH)₂ was radiographically restricted to the coronal half of the root canal system, it produced better results than when it was placed beyond the coronal half.ConclusionsCa(OH)₂ and triple antibiotic paste when used as an intracanal medicament in immature necrotic teeth can help promote further development of the pulp-dentin complex.     

Microbial Evaluation of Traumatized Teeth Treated with Triple Antibiotic Paste or Calcium Hydroxide with 2% Chlorhexidine Gel in Pulp Revascularization

Introduction

Revascularization outcome depends on microbial elimination because apical repair will not happen in the presence of infected tissues. This study evaluated the microbial composition of traumatized immature teeth and assessed their reduction during different stages of the revascularization procedures performed with 2 intracanal medicaments.

Methods

Fifteen patients (7–17 years old) with immature teeth were submitted to the revascularization procedures; they were divided into 2 groups according to the intracanal medicament used: TAP group (n = 7), medicated with a triple antibiotic paste, and CHP group (n = 8), dressed with calcium hydroxide + 2% chlorhexidine gel. Samples were taken before any treatment (S1), after irrigation with 6% NaOCl (S2), after irrigation with 2% chlorhexidine (S3), after intracanal dressing (S4), and after 17% EDTA irrigation (S5). Cultivable bacteria recovered from the 5 stages were counted and identified by means of polymerase chain reaction assay (16S rRNA).

Results

Both groups had colony-forming unit counts significantly reduced after S2 (P < .05); however, no significant difference was found between the irrigants (S2 and S3, P = .99). No difference in bacteria counts was found between the intracanal medicaments used (P = .95). The most prevalent bacteria detected were Actinomyces naeslundii (66.67%), followed by Porphyromonas endodontalis, Parvimonas micra, and Fusobacterium nucleatum, which were detected in 33.34% of the root canals. An average of 2.13 species per canal was found, and no statistical correlation was observed between bacterial species and clinical/radiographic features.

Conclusions

The microbial profile of infected immature teeth is similar to that of primarily infected permanent teeth. The greatest bacterial reduction was promoted by the irrigation solutions. The revascularization protocols that used the tested intracanal medicaments were efficient in reducing viable bacteria in necrotic immature teeth.     

The Effect of Medicaments Used in Endodontic Regeneration Technique on the Dislocation Resistance of Mineral Trioxide Aggregate to Root Canal Dentin

Introduction

The aim of this study was to evaluate the effect of calcium hydroxide (CH) and antibiotic pastes, including a mixture of metronidazole and ciprofloxacin, with and without minocycline or cefaclor, on the dislocation resistance of mineral trioxide aggregate (MTA) to root dentin.

Methods

Eighty single-rooted human mandibular premolars were selected. The teeth were prepared by using the ProTaper system. The prepared teeth were then instrumented to a #6 Peeso reamer to obtain a standard internal diameter of 1.5 mm. The reamers were passed 1 mm beyond apex to simulate immature teeth. The specimens were then randomly divided into a control group (no intracanal medicament was used) and 4 experimental groups that were treated with an intracanal medicament: CH, double antibiotic paste (DAP) with metronidazole and ciprofloxacin, triple antibiotic paste (TAP) with minocycline, or TAP with cefaclor (n = 16). After 3 weeks, the medicaments were removed, and approximately 3 mm of MTA was placed in the coronal third of the canals. A push-out test was used to measure the dislocation resistance between the root dentin and MTA. Data were analyzed by using one-way analysis of variance and Tukey post hoc tests.

Results

The dislocation resistance values of the CH, TAP with minocycline, and TAP with cefaclor groups were similar to those of the control group (P > .05), whereas the DAP group had the lowest dislocation resistance when compared with the other groups (P < .05). Overall, there was a predominance of cohesive failures between root dentin and MTA.

Conclusions

The results of this study indicate that the application of DAP as an intracanal medicament reduced the dislocation resistance of MTA to root dentin.     

Antibacterial Effect and Bioactivity of Innovative and Currently Used Intracanal Medicaments in Regenerative Endodontics

IntroductionThe purpose of this study was to determine the antibacterial effect and bioactivity of triple antibiotic paste (TAP), calcium hydroxide (Ca[OH]₂), and calcium hypochlorite (Ca[OCl]₂).MethodsRoot canals were infected with 3-week-old Enterococcus faecalis biofilm and then medicated for 7 days with TAP, Ca(OH)₂, or Ca(OCl)₂ (n = 10/group). Untreated and uninfected canals were used as positive and negative controls. The antibacterial effect was determined using colony-forming units and a Live/Dead bacterial viability kit. Dental pulp stem cells were seeded on medicated dentin surfaces for 7 days. Sodium thiosulfate and various concentrations of ascorbic acid (1%, 5%, and 10%) were also used to neutralize the samples treated with Ca(OCl)₂ before cell seeding (n = 3 in triplicate). Cell viability and morphology were evaluated using a viability assay and Live/Dead cell analysis. Alkaline phosphatase (ALP) activity was also measured to determine the cells’ mineralization activity.ResultsAll medicaments decreased the initial bacterial load (P < .05). The highest bacterial reduction in the main canal and dentinal tubules was observed in the Ca(OCl)₂ group (P < .05). TAP- or Ca(OH)₂-treated dentin surface improved cell viability and ALP activity compared with the untreated dentin surface (P < .05), whereas Ca(OCl)₂ decreased cell viability and ALP activity (P < .05). Ten percent ascorbic acid neutralized the effect of Ca(OCl)₂ on the treated dentin surface, showing higher cell viability (P < .05) and similar ALP activity with the untreated dentin surface and the other groups (P > .05).ConclusionsCa(OCl)₂ medication improved root canal disinfection against E. faecalis biofilm compared with TAP and Ca(OH)₂. The adverse effects caused by Ca(OCl)₂ on cell viability and mineralization activity can be neutralized with 10% ascorbic acid.     

A titration model for evaluating calcium hydroxide removal techniques

Objective

Calcium hydroxide (Ca(OH)₂) has been used in endodontics as an intracanal medicament due to its antimicrobial effects and its ability to inactivate bacterial endotoxin. The inability to totally remove this intracanal medicament from the root canal system, however, may interfere with the setting of eugenol-based sealers or inhibit bonding of resin to dentin, thus presenting clinical challenges with endodontic treatment. This study used a chemical titration method to measure residual Ca(OH)₂ left after different endodontic irrigation methods.

Material and Methods

Eighty-six human canine roots were prepared for obturation. Thirty teeth were filled with known but different amounts of Ca(OH)₂ for 7 days, which were dissolved out and titrated to quantitate the residual Ca(OH)₂ recovered from each root to produce a standard curve. Forty-eight of the remaining teeth were filled with equal amounts of Ca(OH)₂ followed by gross Ca(OH)₂ removal using hand files and randomized treatment of either: 1) Syringe irrigation; 2) Syringe irrigation with use of an apical file; 3) Syringe irrigation with added 30 s of passive ultrasonic irrigation (PUI), or 4) Syringe irrigation with apical file and PUI (n=12/group). Residual Ca(OH)₂ was dissolved with glycerin and titrated to measure residual Ca(OH)₂ left in the root.

Results

No method completely removed all residual Ca(OH)₂. The addition of 30 s PUI with or without apical file use removed Ca(OH)₂ significantly better than irrigation alone.

Conclusions

This technique allowed quantification of residual Ca(OH)₂. The use of PUI (with or without apical file) resulted in significantly lower Ca(OH)₂ residue compared to irrigation alone.     

Comparison of final irrigation techniques in removal of calcium hydroxide

The aim of this study was to compare new irrigation systems with a conventional irrigation technique for the removal of inter‐appointment calcium hydroxide [Ca(OH)₂]. Forty‐seven extracted human single‐rooted teeth were instrumented, and Ca(OH)₂ paste was placed into root canals by using a lentulo spiral at the apical third. Teeth were randomly divided into three groups according to different irrigation protocols using a 30‐gauge slot‐tipped needle, EndoVac system and ProUltra® PiezoFlow? ultrasonic irrigation system. Scanning electron microscopic images of the selected root canal surfaces (cervical, middle and apical third) were evaluated using a 5‐grade scale. The influence of the irrigation system was evaluated using a two‐way analysis of variance test and Tukey's test. The EndoVac and PiezoFlow groups demonstrated the lowest scale values (cleanest canals); however, there was no statistical difference between these two groups. The conventional irrigation group exhibited significantly higher scores (P < 0.05). The conventional needle irrigation was not sufficient to remove Ca(OH)₂ from the root canal system. Irrigation with EndoVac and PiezoFlow? ultrasonic irrigation systems improved the removal of the intracanal medicament resulting in cleaner root canal walls.     

Antibacterial Efficacy of MTAD Final Rinse and Two Percent Chlorhexidine Gel Medication in Teeth with Apical Periodontitis: A Randomized Double-blinded Clinical Trial

IntroductionClinical 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.MethodsCanals 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.ResultsBacterial 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.ConclusionsThe final rinse with MTAD and medication with CHX did not reduce bacterial counts beyond levels achieved by canal preparation with NaOCl.