Comparative Evaluation of Residual Antibacterial Substantivity of Chlorhexidine, MTAD and Chitosan Against Enterococcus Faecalis in Human Root Dentin - An In vitro Study.

Introduction: Complex anatomy of the root canal system results in incomplete debridement with mechanical instrumentation, leaving some areas or root canal walls untouched. There comes the significance of endodontic irrigants with residual antibacterial substantivity which prolongs the post-antibiotic effect, thereby improving the success and predictability of endodontic treatment. Aim: To comparatively evaluate the residual antibacterial substantivity of 2% chlorhexidine, Biopure MTAD and 2% chitosan against Enterococcus faecalis at intervals of 1, 14 and 28 days. Materials and Methods: Seventy-five therapeutically extracted permanent single rooted mandibular premolars teeth were selected. Dentin blocks of 4 mm thickness were prepared and enlarged to 1.6 mm. The autoclaved blocks were inoculated with 24-hour colonies of pure cultures of E. faecalis for 14 days. After the contamination period, canals of each dentin block were irrigated with 5 ml of sterile saline and dried with sterile paper points. A total of 75 dentin blocks were randomly divided into five groups as follows: Group A (21 specimens): 2% chlorhexidine, Group B (21 specimens): Biopure MTAD, Group C (21 specimens): 2% chitosan, Group D (6 specimens): positive control (infected dentin tubes) and Group E (six specimens): negative control (sterile dentin tubes). Then, the lumens of dentin blocks were irrigated with the respective irrigants for 10 mins and were dried using sterile paper points. The specimens were then incubated at 37°C for 28 days to maintain humidity. At experimental intervals of 1, 14 and 28 days, dentin shavings were removed from the canals of respective groups by circumferential filing with sterile no. 35 Hedstrom files. The powdered dentin samples obtained with each dentin block were observed for colony forming units (CFUs) using a Digital Colony counter and were expressed as CFUs/mL. Result: All the irrigants in the study showed a significant decrease in CFUs from day 1 to day 28 indicating that they have residual antibacterial substantivity against E. faecalis. Group B (Biopure MTAD) showed significantly least mean CFUs compared to Group A (2% CHX) and Group C (2% chitosan) against E. faecalis at B1(day 1), B2(day 14) and B3(day 28). Group A (2% CHX) showed significantly higher mean CFUs than Group C (2% chitosan) at A1(day 1). Group C (2% chitosan) showed significantly higher mean CFUs compared to Group A (2% CHX) at C2(day 14) and C3 (day 28). Conclusion: MTAD showed statistically higher residual antibacterial substantivity against E. faecalis at experimental periods of 1, 14 and 28 days. The residual antibacterial effect of 2% chitosan was better compared to 2% CHX at day 1. The residual antimicrobial substantivity of 2% CHX was higher compared to 2% chitosan at intervals of 14 and 28 days.

Water-soluble vitamin-E for enhancing fluorescence diagnosis in infected human dentine treated with NaOCl.

INTRODUCTION: Bacterial fluorescence methods are of interest in endodontics for informing endpoints for debridement. This study explored potential fluorescence quenching reversal effects of a water-soluble vitamin E conjugate (d-α-Tocopherol polyethylene glycol 1000 succinate, TPGS) when applied to polymicrobial biofilms grown on dentine that had been exposed to sodium hypochlorite (NaOCl) to cause quenching. METHOD: Extracted human teeth were debrided, embedded in transparent acrylic resin and sectioned. After smear layer removal, tooth dentine sections were inoculated with a polymicrobial inoculum, and cultured for 7 days to create biofilms. Samples (n = 8 per group) were exposed to 1 % or 4 % NaOCl for 2 or 4 min, and then treated with TPGS. Bacterial fluorescence readings under laser excitation at 655 nm were assessed over 10 min using a calibrated DIAGNOdent device. All data were assessed for normality (Kolmogorov-Smirnov test) and analysed with ANOVA followed by Bonferroni post-hoc tests. RESULTS: NaOCl at both concentrations quenched fluorescence readings of biofilms grown on dentine samples, with a maximal reduction of 40.4 % at 5 min after 4 % NaOCl. Treatment with TPGS gave faster recovery of fluorescence readings compared to the control at 5 and 10 min. CONCLUSION: The water-soluble antioxidant TPGS partially reversed fluorescence quenching caused by NaOCl. This agent may have value clinically for reducing the time needed for fluorescence readings to recover when NaOCl is used as an irrigant. This will facilitate more accurate assessment of endpoints for canal debridement.

Effect of Different Irrigating Solutions on Root Canal Dentin Microhardness-A Systematic Review with Meta-Analysis.

The aim of this study was to evaluate the effect of different irrigating solutions as well as their combination and activation modes on root canal dentin microhardness. The protocol was registered in PROSPERO and PRISMA guidelines were followed. The structured question was as follows: "Which type of irrigating solution used in endodontic treatment causes more change in dentin microhardness?" The literature was screened via PubMed, Google Scholar, Scopus, and Science Direct. The last search was carried out in February 2023 with English language restriction. Two reviewers independently performed screening and evaluation of articles. A total of 470 articles were retrieved from all the databases, whereas only 114 articles were selected for full-text analysis. After applying eligibility criteria, 44 studies were evaluated and included in this review. The results showed that with increased contact time with irrigants, dentin microhardness decreases. Increased contact time with sodium hypochlorite (NaOCl) was associated with more reduction in dentin microhardness compared with other irrigants. Other irrigants, with the exception of distilled water, including EDTA, citric acid, herbal irrigants, glycolic acid, phytic acid, etc., in this study significantly decreased dentin microhardness. The maximum reduction in dentin microhardness was seen with 2.5% NaOCl after 15 min of contact time. The use of irrigating solutions alters the chemical composition of dentin, thereby decreasing its microhardness, which affects the clinical performance of endodontically treated teeth.

Engineering a Microphysiological Model for Regenerative Endodontic Studies.

Dental pulp infections are common buccal diseases. When this happens, endodontic treatments are needed to disinfect and prepare the root canal for subsequent procedures. However, the lack of suitable in vitro models representing the anatomy of an immature root canal hinders research on regenerative events crucial in endodontics, such as regenerative procedures. This study aimed to develop a 3D microphysiological system (MPS) to mimic an immature root canal and assess the cytotoxicity of various irrigating solutions on stem cells. Utilizing the Dental Stem Cells SV40 (DSCS) cell line derived from human apical papilla stem cells, we analyzed the effects of different irrigants, including etidronic acid. The results indicated that irrigating solutions diminished cell viability in 2D cultures and influenced cell adhesion within the microphysiological device. Notably, in our 3D studies in the MPS, 17% EDTA and 9% 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) irrigating solutions demonstrated superior outcomes in terms of DSCS viability and adherence compared to the control. This study highlights the utility of the developed MPS for translational studies in root canal treatments and suggests comparable efficacy between 9% HEBP and 17% EDTA irrigating solutions, offering potential alternatives for clinical applications.

Interactions Between Calcium Hypochlorite and Irrigants Commonly Used in Endodontic Practice: A Chemical Analysis.

INTRODUCTION: This study aimed to identify possible products resulting from chemical interactions between calcium hypochlorite (Ca[OCl]2) and other irrigants for endodontic use using electrospray ionization quadrupole time-of-flight mass spectrometry. METHODS: The 5.25% Ca(OCl)2 was associated with either 70% ethanol solution, distilled water, saline solution (0.9% sodium chloride), 5% sodium thiosulfate, 10% citric acid, 17% ethylenediaminetetraacetic acid (EDTA), or 2% chlorhexidine (CHX). The reaction ratio was 1:1 and the products obtained were analyzed by electrospray ionization quadrupole time-of-flight mass spectrometry. RESULTS: The interactions between Ca(OCl)2 and CHX generated an orange-brown precipitate, without identification of para-chloroaniline and between Ca(OCl)2 and sodium thiosulfate, a milky-white precipitate. Furthermore, when the oxidizing agent was associated with EDTA and citric acid, chlorine gas was released. As for the other associations, 70% ethanol, distilled water, and saline solution, no precipitation or gas release occurred. CONCLUSIONS: The orange-brown precipitate occurs due to the chlorination of guanidine nitrogens, and the milky-white precipitate is due to the partial neutralization of the oxidizing agent. The release of chlorine gas occurs due to the low pH of the mixture, which results in the rapid formation and decomposition of chlorine. In this context, an intermediate rinsed with distilled water, saline solution, and ethanol between Ca(OCl)2 and CHX, citric acid, and EDTA seems to be appropriate to prevent the formation of by-products when these irrigants need to be used in the canal. Furthermore, if it is necessary to use sodium thiosulfate, a larger volume of the solution must be used compared to that used for the oxidizing solution.

Efficacy of Chlorine Dioxide as an Endodontic Irrigant for Pulp Dissolution in vitro

Determine the efficacy of 5 % chlorine dioxide as an endodontic irrigant for pulp dissolution. Thirty five samples of human dental pulp were obtained, previously weighed and immersed in three solutions= 5 % ClO 2, 5.25 % NaOCl and saline (control group), for 10 minutes at 32 ºC; they were dried and reweighed. Then the weight loss was compared to the original weight and analyzed statistically. 5.25 % NaOCl and 5 % ClO 2 dissolved the dental pulp samples more effectively than saline (p> 0.001). No statistically significant difference was found between the tissue dissolving proper ties of 5.25 % NaOCl and 5 % ClO2 (p=0.893). 5 % ClO2 is effective in dissolving human dental pulp tissue.

El objetivo de este estudio fue determinar la eficacia del dióxido de cloro al 5 % como irrigante endodóntico para la disolución pulpar. Se obtuvieron 35 muestras de pulpa dental humana, se pesaron previamente y se sumergieron en tres soluciones= 5 % ClO2, 5.25 % NaOCl y suero fisiológico (grupo control), durante 10 minutos a 32ºC; se secaron y se pesaron de nuevo. Luego se comparó la pérdida de peso del peso original y se analizó estadísticamente. NaOCl al 5.25 % y ClO2 al 5 % disolvieron las muestras de pulpa dental con más eficacia que el suero fisiológico (p> 0.001). No se encontró diferencias estadísticamente significativas entre las propiedades de disolución de tejido de NaOCl al 5.25 % y ClO2 al 5 % (p=0.893) ClO2 al 5 % es eficaz para disolver tejido de pulpa dental humana.

Fluorescence characteristics of E. faecalis in dentine following treatment with oxidizing endodontic irrigants.

INTRODUCTION: This study aimed to assess changes in the fluorescence characteristics of Enterococcus faecalis in human dentine over a period of 24 h following treatment with endodontic irrigants. METHOD: Sterilised, non-functional extracted third molars were embedded in acrylic resin and uniformly sectioned into 2 mm thick dentine sections. After the removal of smear layer, the dentine sections were inoculated with E. faecalis and cultured for 7 days. The infected dentine sections were subsequently treated with different concentrations of sodium hypochlorite (NaOCl) and hydrogen peroxide (H2O2). Bacterial fluorescence readings were assessed at different time points using a calibrated laser device. All data were assessed for normality (Kolmogorov Smirnoff test) and analysed using ANOVA with Bonferroni post-hoc tests. RESULTS: Fluorescence readings were quenched when E. faecalis infected human dentine sections were treated with oxidizing irrigants in vitro. Throughout a 24-hour period, fluorescence recovered in part but did not return to baseline level. CONCLUSION: The fluorescence quenching effect of these oxidizing agents needs to be considered when using laser fluorescence in assessing the quality of root canal debridement or disinfection.

A proposed classification system for herbal endodontic irrigants.

Irrigating solutions are an essential adjunct in the root canal therapy for the complete disinfection of the root canal space. The recent trend focuses on the use of herbal extracts in endodontics owing to their advantages and minimal side effects. In view of this, we have proposed a classification system to classify herbal endodontic irrigants as currently, there is no standard classification available. This structured classification will give an overview of the diversity of herbal irrigants and also highlight the potential use of each of them. Thus, it will be easy to segregate the study and use the herbal endodontic irrigants according to the requirements. The proposed classification system shall prove to be highly beneficial to the students, researchers, and clinicians.

A new phantom to evaluate the tissue dissolution ability of endodontic irrigants and activating devices.

OBJECTIVE: The aim of this study was to introduce a gelatin/bovine serum albumin (BSA) tissue standard, which provides dissolution properties identical to those of biological tissues. Further, the study evaluated whether the utilization of endodontic activating devices led to enhanced phantom dissolution rates. MATERIALS AND METHODS: Bovine pulp tissue was obtained to determine a benchmark of tissue dissolution. The surface area and mass of samples were held constant while the ratio of gelatin and BSA were varied, ranging from 7.5% to 10% gelatin and 5% BSA. Each sample was placed in an individual test tube that was filled with an appropriate sodium hypochlorite solution for 1, 3, and 5 minutes, and then removed from the solution, blotted dry, and weighed again. The remaining tissue was calculated as the percent of initial tissue to determine the tissue dissolution rate. A radiopaque agent (sodium diatrizoate) and a fluorescent dye (methylene blue) were added to the phantom to allow easy quantification of phantom dissolution in a canal block model when activated using ultrasonic (EndoUltra) or sonic (EndoActivator) energy. RESULTS: The 9% gelatin + 5% BSA phantom showed statistically equivalent dissolution to bovine pulp tissue at all time intervals. Furthermore, the EndoUltra yielded significantly more phantom dissolution in the canal block than the EndoActivator or syringe irrigation. CONCLUSIONS: Our phantom is comparable to biological tissue in terms of tissue dissolution and could be utilized for in vitro tests due to its injectability and detectability.

Comparative evaluation of substantivity of two biguanides - 0.2% polyhexanide and 2% chlorhexidine on human dentin.

BACKGROUND: Substantivity is one of the desirable characteristics of root canal irrigants. Among conventional endodontic irrigants, only chlorhexidine (CHX) is known to exert significant substantivity on root canal dentin. This study explored the substantivity activity of a polymeric biguanide-poly hexamethylene biguanide (PHMB). AIM: The aim of this study was to determine the substantivity of a polymeric biguanide - 0.2% PHMB and compare it with that of 2% CHX. MATERIALS AND METHODS: To evaluate and compare the substantivity of 0.2% PHMB and 2% CHX on root canal dentin, dentin disks were prepared and substantivity after 1 h, 24 h, 7 days and 21 days was measured using spectrophotometry. STATISTICAL ANALYSIS USED: The data so obtained were analyzed, and the intergroup comparison was made using unpaired t-test. RESULTS: The results of this study indicated that 0.2%. PHMB exerts significantly greater substantivity than 2% CHX on human dentin. CONCLUSION: Within the limitations, this study supports the use of 0.2% polyhexanide as an endodontic irrigant based on its property of substantivity.

Oxidising agents and its effect on human dentine fluorescence diagnostic measurements.

BACKGROUND: The ability to determine the effectiveness of root canal disinfection in real-time prior to the final root filling could significantly influence the management and treatment outcomes of root canal therapy. Laser fluorescence devices can detect bacterial fluorescence in real-time, however since quenching of fluorescence is a possible confounding factor, this study explored the effects of oxidising endodontic irrigants on laser fluorescence in dentine. METHODS: A total of 78 transverse 2 mm thick sections were prepared from the crowns of sterilised extracted non-functional third molars that had been embedded in acrylic resin. The dentine sections where then treated with different concentrations of sodium hypochlorite and hydrogen peroxide, with or without further rinsing with distilled water wash. Fluorescence values were recorded over 24 h using the DIAGNOdent laser fluorescence device. RESULTS: Both sodium hypochlorite and hydrogen peroxide cause quenching of fluorescence readings of human dentine, with reductions of 30-60% in fluorescence readings. The quenching effect occurred quickly, and recovery to baseline readings took from 1 h to 24 h. Rinsing with water reduced but did not eliminate the quenching effect. CONCLUSION: The use of laser fluorescence to reliably detect root canal bacteria porphyrins in real-time could significantly influence the management of teeth needing root canal therapy. This study highlighted the quenching effects of some root canal irrigants on human teeth root dentine, a variable that should be considered and controlled prior to using lasers to assist in assessing root canal sterility.

Influence of Different Types of Root Canal Irrigation Regimen on Resin-based Sealer Penetration and Pushout Bond Strength.

Introduction The main objective of root canal treatment is to eliminate the micro-organism from the root canal system and three-dimensional obturation. The proper cleaning and shaping can be accomplished only by using appropriate instruments and effective irrigants during the root canal treatment. Aim To evaluate the influence of three different final irrigation regimen on depth of penetration of root canal sealers and push-out bond strength of obturation material. Materials and methods Thirty-six extracted single-rooted mandibular premolar human teeth with straight canals were decoronated and instrumented according to groups. Group I: Root canals were irrigated with 3% sodium hypochlorite (NaOCl), then irradiated with 980 nm diode laser (n = 12), Group II: Root canals were irrigated with 3% NaOCl, followed by 17% ethylenediaminetetraacetic acid (EDTA) (n = 12), Group III: Root canals were irrigated with 3% NaOCl, followed by 10% citric acid (n = 12). In each sample, single cone obturation was done with gutta-percha using AH plus sealer incorporated with rhodamine B dye. After seven days coronal, middle and apical thin cross sections were made for evaluation of dentinal tubule sealer penetration depth and pushout bond strength using confocal laser scanning microscope (CLSM) and universal testing machine, respectively. Statistical analysis among the three groups was done by using Kruskal-Wallis and post hoc test. Results Mean tubular penetration depth between diode laser (136.57 ± 48 µm), EDTA (130.56 ± 53 µm) and citric acid (113.37 ± 34 µm; P < 0.05) showed statistically highly significant results. Pushout bond strength did not differ significantly between diode laser (1.21 ± 0.48 Mpa), EDTA (1.05 ± 0.45 Mpa) and citric acid (0.93 ± 0.44 Mpa; P > 0.05). Conclusion Mean tubular penetration depth of AH plus sealer was better in diode laser than in EDTA and citric acid. Average push-out bond strength of obturation material did not differ significantly between diode laser, EDTA and citric acid.

Comparative Evaluation of Antifungal Activity of Octenidine: An In Vitro Confocal Laser Study.

AIM: The aim of this study was to evaluate the antifungal efficacy of a novel endodontic irrigant octenidine against conventional irrigants sodium hypochlorite and EDTA on Candida albicans growth in the young and old population by calculating the number of colonies formed and by qualitative identification of dead/viable fungi by Confocal laser scanning microscopy (CLSM) method. MATERIALS AND METHODS: The total number of samples used in the study was eighty samples after decoronation of the crown portion the middle third of root canal. Each group was subdivided into four subgroups with various irrigation protocols: (A) 17% EDTA + 5.25% NaOCl, (B) 100% Octenisept, (C) 17% EDTA + 5.25% NaOCl + 1% clotrimazole, and (D) phosphate buffer saline. After completion of irrigation ATCC samples (90028) of C. albicans were inoculated with 5 mL of peptone water each and incubated at 37°C for 72 hours to attain the turbidity corresponding to 0.5 McFarland standards CFU. Eight samples were analyzed for the formation of candidal colonies, and two samples for the assessment of viability of Candida by confocal laser scanning microscope in each subgroup. RESULTS: Comparison of antifungal efficacy of endodontic irrigants employed in the young and old populations revealed a significant reduction in the mean values of CFU and the mean values of percentage of non-viable microorganism by CLSM method. A positive relationship was revealed in the younger population which had a better antifungal efficacy than the older population in all the irrigant subgroups evaluated in the study. CONCLUSION: All the endodontic irrigants employed in our study had a good antifungal efficacy against Candida albicans. Octenisept had a maximum antifungal efficacy, while phosphate saline showed the least efficacy in both age groups, which was quantitatively evaluated by CFU method, and the same was confirmed through qualitative evaluation by CLSM method. CLINICAL SIGNIFICANCE: Candida albicans plays a major role in the establishment and pathogenesis of failed root canal treatment. Age-related changes alter the adhesion potential of dentin, in turn influence the outcome of endodontic therapy. Octenidine, a novel antifungal agent, can be substituted over the conventionally used EDTA and NaOCl with less adverse effects.

Azadirachta indica A. juss, Morinda citrifolia L. and Triphala as herbal endodontic irrigants: A scoping review.

Background: The success of the root canal treatment depends on the complete elimination of the microflora, biofilms and smear layer from the pulp space. A wide variety of chemical endodontic irrigants are available to achieve disinfection and thorough debridement besides mechanical means. However, detrimental properties such as allergic potential, cytotoxicity, antimicrobial resistance and safety concerns have intrigued researchers over the years to look for safer options. Aim: The review is aimed at providing comprehensive information of the studies evaluating the efficacy of Azadirachta indica A. juss (A. indica), Morinda citrifolia L. (M. citrifolia) and Triphala (fruits of Emblica officinalis Gaertn., Terminalia chebula (Gaertn.) Roxb. and Terminalia belerica Retz.) as herbal endodontic irrigants. Materials and methods: The literature review was conducted using indexed databases (PubMed, Google Scholar, Cochrane) electronically for publications in peer-reviewed journals for relevant articles evaluating the efficacy of A. indica, Triphala, M. citrifolia as endodontic irrigant from the year 1985-March 2020. Results: A total of 58 studies were identified for full text reviewing after duplicate removal and screening title and abstracts. A total of 32 studies were included and processed for data extractions. Conclusion: Various in-vitro/in-vivo studies utilizing these herbal irrigants have documented promising results and hold the potential to replace chemical endodontic irrigants in routine practice but more preclinical and clinical trials are needed to substantiate these results before they can conclusively be recommended as intracanal irrigating solutions.

Comparative Study of Antifungal Efficacy of Various Endodontic Irrigants with and without Clotrimazole in Extracted Teeth Inoculated with Candida albicans.

AIM AND OBJECTIVE: To assess the application of clotrimazole (1%) as a complementary antifungal agent along with sodium hypochlorite (5.25%), chlorhexidine gluconate (2%), and doxycycline hydrochloride (5%) against Candida albicans. MATERIALS AND METHODS: Seventy freshly extracted single-rooted premolars with matured apices were collected, stored, and handled according to the Occupational Safety and Health Administration (OSHA) and the Center for Disease Control and Prevention (CDC) guidelines and recommendations. These were divided into three groups (two tests and one control group) depending on irrigants used. The efficacy of each irrigant group was compared. The observations were statistically analyzed by the multiple intergroup comparisons using ANOVA and Scheffe multiple comparisons (p < 0.001). RESULTS: The sodium hypochlorite (group IA-mean 129.6) has shown a statistically significant decrease in colony-forming units (CFUs) (p < 0.01) on comparison with chlorhexidine [(IB) mean 190.2]. A similar result was obtained in comparison with the sodium hypochlorite group (IA) and doxycycline HCl group [(IC) mean 318.4] and also between the sodium hypochlorite group (IA) and the control group [(III) mean 554.2]. The intragroup comparison of group II, group IIA (mean 63.3), and group IIB (mean 73.8) showed no statistically significant difference. Group III (mean 554.2) was the least effective of all the subgroups. CONCLUSION: Sodium hypochlorite showed better antifungal efficacy than chlorhexidine and doxycycline when used alone. The addition of clotrimazole increased the efficiency of doxycycline also, but it was less compared to sodium hypochlorite and chlorhexidine. Within the limitations of this study, the inclusion of 1% clotrimazole increased the antifungal efficacy of all the three irrigants. CLINICAL SIGNIFICANCE: Our study compared the efficacy of the various endodontic irrigants and also determined their efficiency with the addition of the antifungal agent. Clotrimazole (1%) addition in irrigating solutions showed better results and promoted faster healing.

Determination of the Minimum Inhibitory Concentrations of Alexidine and Chlorhexidine Against Enterococcus faecalis and Candida albicans: An In Vitro Study.

INTRODUCTION: The root canal system must be mechanically instrumented and chemically cleaned using various antimicrobial irrigants in a sequential manner or in combination for the elimination of necrotic pulp tissue and reducing the number of root canal bacteria. For this reason, new methods and materials are continuously being developed to achieve the objectives of endodontic treatment. MATERIALS AND METHODS: E. faecalis (ATCC 29212) and C. albicans (ATCC 90028) standard strains were used for this study. Colonies of E. faecalis and C. albicans were harvested from the agar plates and suspended in 4 mL of phosphate buffered saline (PBS). Microorganisms were diluted to obtain a suspension of approximately 108 colony-forming units/mL (CFU/mL) in sterile PBS using McFarland standard tubes no. 0.5. RESULTS: After a two-minute contact time, all alexidine (ALX) concentrations used in this study eradicated all E. faecalis strains, while chlorhexidine (CHX) didn't kill 100% of E. faecalis at 0.25% and lower concentrations even after a five-minute contact time. ALX also eradicated C. albicans at all concentrations even after a one-minute contact time. CHX showed antifungal activity against C. albicans at all concentrations higher than 0.031% after a one-minute contact time. CONCLUSION: A 0.0156% concentration of ALX can be a good alternative to CHX as an irrigation solution in endodontic treatment when used for one minute against E. faecalis and C. albicans.

Análise da erosão da dentina radicular após irrigação com hipoclorito de sódio em diferentes concentrações por meio de microscopia eletrônica de varredura / Analysis of radicular dentin erosion after sodium hypochlorite irrigation at different concentrations by scanning electron microscopy

Objetivo: Avaliar a erosão dentinária após a irrigação com hipoclorito de sódio (NaOCl) em diferentes concentrações por meio de microscopia eletrônica de varredura (MEV). Material e método: Foram utilizados doze dentes humanos unirradiculares divididos em 4 grupos (n=3) conforme solução utilizada: NaOCl 1%, NaOCl 2,5%, NaOCl 5,0% e água destilada (controle). Todos os canais radiculares foram preparados utilizando o sistema BioRace, irrigados com a solução do grupo correspondente e EDTA 17%. Ranhuras longitudinais foram preparadas para clivar as raízes. Os espécimes foram avaliados em MEV. A erosão dentinária foi analisada e registrada considerando os seguintes scores: Score 1 - não houve erosão na dentina; score 2 - erosão moderada e score 3 - erosão severa. Resultado: Praticamente não observou-se erosão (score 1) no grupo preparado com água destilada, em contrapartida, o grupo de dentes que foram irrigados com NaOCl 5%, obteve a maior prevalência de erosão severa (score 3). No grupo irrigado com NaOCl 1% houve prevalência de score 1 no terço cervical e de score 2 no terço médio, já no terço apical os 3 scores foram observados. No grupo irrigado com a solução de hipoclorito de sódio a 2,5% houve erosão dentinária predominantemente moderada (score 2) em todos os terços. Conclusão: A erosão dentinária foi diretamente proporcional à concentração de hipoclorito de sódio.

Objective: To evaluate the dentin erosion after sodium hypochlorite irrigation in different concentrations by scanning electron microscopy (SEM). Methods: It was used twelve singlerooted teeth divided into 4 groups (n = 3) according to the used solution: 1% NaOCl, 2.5% NaOCl, 5% NaOCl and distilled water (control). All root canals were prepared using BioRace system, irrigated with the solution of the corresponding group and 17% EDTA. Longitudinal grooves were made to cleave the roots. The specimens were evaluated in scanning electron microscopy. The dentin erosion level was recorded considering the following criteria: Score 1 - there was no erosion on dentin; score 2 - moderate erosion and score 3 - Severe erosion. Result: The dentin erosion was proportional to the concentration of sodium hypochlorite. Practically, there was no erosion (score 1) in the group prepared with distilled water, on the other hand, the group irrigated with 5% NaOCl had the highest percentage of severe erosion, score 3. The group irrigated with 1% NaOCl had the prevalence of score 1 in cervical third and score 2 in the middle third, however all the scores were observed in apical third. In group irrigated with 2,5% sodium hypochlorite there was, predominantly, moderate dentin erosion (score 2) in all thirds. Conclusion: Dentin erosion was directly proportional to the concentration of sodium hypochlorite

Effect of Qmix and Other Irrigants on Dentin Adhesives in Pulp Chambers of Primary Teeth: SEM Study.

OBJECTIVE: To compare the effect of different endodontic irrigants on microleakage of adhesives used within pulp chamber of primary molars. STUDY DESIGN: 72 Primary molars were divided into 6 groups, according to 3 irrigants and 2 adhesives used. After de-roofing the pulp chamber, pulp was extirpated. In 36 samples, pulp chambers were bonded with Xeno V+ after irrigation with either QMix (Group1); 17%EDTA+5%NaOCl (Group2) or normal saline (Group3) and in other half samples, pulp chambers were bonded with SinglebondUniversal after irrigation with either QMix (Group 4); 17%EDTA+5% NaOCl (Group5) or normal saline (Group 6). All the samples were restored with Filtek Z350. Ten teeth from each group were assessed for dye penetration. Two samples in each group were viewed under scanning electron microscope. Data was statistically analyzed using Mann-Whitney and Kruskal Wallis tests at a significance level of P < 0.05. RESULTS: Mean microleakage scores were: Group 1-1.5±0.70, Group 2-1.6±.51, Group 3-2.4±0.96, Group 4-1.2±0.42, Group 5-1.2±0.42, Group 6-1.1±0.32. CONCLUSIONS: Irrigation with QMix significantly reduced the microleakage of XenoV+ but had no significant effect on microleakage of SinglebondUniversal. Irrigation with EDTA/NaOCl or QMix had no detrimental effect on the sealing ability of either of the adhesive tested.

Interaction of Hydroxyethylidene bisphosphonate (HEBP) with other endodontic irrigants on tissue dissolving capacity and antimicrobial effect

PURPOSE: The purpose of this study was to evaluate tissue dissolving capacity, antimicrobial effect of Hydroxyethylidene bisphosphonate (HEBP) interacting with sodium hypochlorite (NaOCl), Ethylenediaminetetraacetic acid (EDTA) as conventional endodontic irrigants and to determine tissue dissolving efficacy depended on temperature. MATERIALS AND METHODS: A total of 80 bovine muscles were randomly distributed into 8 groups (n = 10). After their initial weights determined on a precision scale, the specimens in each group were immersed in the solutions for 5, 10 and 15 min and reweighted at each time period. Agar diffusion test inoculated with Enterococcus faecalis was performed for antimicrobial effect of each endodontic irrigants. RESULTS: The ability to dissolve organic matter was greater in NaOCl group following NaOCl and HEBP mixture. Heated NaOCl (40℃) and NaOCl/HEBP mixture was greater tissue dissolving efficacy than room temperature (25℃). Antimicrobial effect was greater and significant in the following order EDTA > EDTA + 1% NaOCl > 1% NaOCl ≥ 1% NaOCl + HEBP. CONCLUSION: HEBP as soft chelating agent does not disturb antimicrobial effect and less affected tissue dissolving efficacy as inherent properties of NaOCl. In the heated NaOCl/HEBP mixture analyzed, it dissolved more the organic matter than room temperature.

In vitro assessment of the tooth staining potential of endodontic materials in a bovine tooth model.

BACKGROUND/AIMS: Traumatized teeth requiring endodontic intervention may discolor as a result of the treatment performed. Thus, the aim was to investigate the discoloration potential of different endodontic cements, dressings, and irrigants used in dental traumatology. MATERIALS AND METHODS: Cylindrical cavities were prepared in 330 bovine enamel-dentine blocks (10 × 10 × 3.5 mm), leaving 2 mm of enamel and dentine on the labial side. The specimens were randomly assigned to 22 groups (n = 15). The cavities were filled with a range of endodontic materials, sealed with composite and stored in physiological saline. The color of the labial enamel surface was measured with a spectrophotometer at 7 time intervals: before (T0) and after the placement of the test material (T1 = baseline), after 1 week (T2), 1 month (T3), 3 months (T4), 6 months (T5), and 12 months (T6). The color difference values (ΔE) were calculated and further analyzed by anova and the Tukey-Kramer post hoc test (α = 0.05). RESULTS: After 12 months, significant staining was observed among the endodontic cements only in the Portland cement group with additional bismuth oxide (H-MED PC BiOx; ΔE 22.2). Specimens with other commercially available calcium silicate cements containing bismuth oxide were not significantly discolored. All specimens with endodontic dressings and irrigants were color stable except the tested triple antibiotic paste (M-TreVitaMix; ΔE 14.9) and the double antibiotic paste (N-BiMix; ΔE 14.9). Both mixtures did not contain tetracycline derivatives. CONCLUSIONS: The presence of bismuth oxide in calcium silicate cements was not shown to be a reliable predictor for tooth discoloration. Antibiotic pastes without tetracycline derivatives do not guarantee the color stability of teeth.