Antimicrobial activity of calcium hydroxide in endodontics: a review

Anterior Palatal Radicular Cyst: A Case Report

The most prevalent kind of odontogenic cysts is radicular cysts, which usually develop from the epithelial remnants in the periodontal ligament as a result of inflammation that follows pulp necrosis. We report a case of a 49-year-old male patient who complained of painless swelling in the maxillary anterior region, which turned out to be a radicular cyst. Upon clinical examination, a soft, nontender swelling that fluctuated was found. A periapical lesion was found upon radiographic assessment. A radicular cyst was tentatively diagnosed based on clinical and radiological features. The treatment plan included enucleation, restoration of the defect with bone graft, and endodontic therapy with antibiotics. Endodontic therapy was administered after the cystic lesion was surgically removed. The diagnosis of a radicular cyst was validated by histopathological analysis. The significance of a multidisciplinary approach for the successful management of radicular cysts is emphasized in this case report, which also underscores the need for a comprehensive clinical and radiographic evaluation for accurate diagnosis. Prompt identification and suitable intervention are essential to avert possible complications and guarantee successful treatment results.

Diacetylcurcumin: a novel strategy against Enterococcus faecalis biofilm in root canal disinfection

Aim: We evaluated Diacetylcurcumin (DAC), a derivative of curcumin, for its antibacterial and antibiofilm properties against Enterococcus faecalis. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined, along with antibiofilm potential and toxicity in Galleria mellonella. Additionally, in silico computational analysis was performed to understand its mechanisms of action. Results & conclusion: DAC demonstrated significant antibacterial effects, with MIC and MBC values of 15.6 and 31.25 μg/ml, respectively, and reduced biofilm formation. A synergistic effect, reducing biofilm by 77%, was observed when combined with calcium hydroxide. G. mellonella toxicity tests confirmed DAC's safety at tested concentrations, suggesting its potential for use in root canal disinfection products.

Comparison of Antibacterial Efficacy of Triple Antibiotic-Loaded Hydrogel Versus Modified Triple Antibiotic-Loaded Hydrogel as Intracanal Medicament Against Enterococcus faecalis: An In vitro Study

OBJECTIVE

Triple antibiotic paste (TAP) is known to have an essential role in the success of endodontic treatment by eliminating pathogens from the root canal system. Unfortunately, it causes discolouration and cytotoxicity at high concentrations. The objective of this research was to assess and compare the antimicrobial effectiveness of various concentrations (1 mg, 5 mg, 10 mg) of TAP, TAP hydrogel (TAPH), M-TAP, and M-TAP hydrogel (MTAPH) against Enterococcus faecalis.

METHODS

The agar well diffusion method was used to assess the antibiotic sensitivity of the following intracanal medicaments: TAP (ciprofloxacin, metronidazole, and minocycline) mixed in a ratio of 1: 1: 1; TAPH, M-TAP (ciprofloxacin, metronidazole, and amoxicillin), M-TAPH and plain hydrogel. Each tested medicament was individually evaluated for its antimicrobial activity against Enterococcus faecalis. Structural and topographical characterisation were analysed using a Scanning Electron Microscope (SEM) and interpreted using ImageJ software. A microdilution broth test was performed to examine the minimum inhibitory concentration and minimum bactericidal concentration (MBC) of M-TAP and TAP.

RESULTS

Except for the plain hydrogel, M-TAP and hydrogel and TAP and hydrogel showed significantly varied inhibitory zones at different concentrations. M-TAPH showed the highest mean zone of inhibition of 21.6, 33.33 and 38.0 mm at a concentration of 1, 5, and 10 mg/mL when compared to TAPH, which showed a mean zone of inhibition of 3.3 mm,12.3 mm, 21.3 mm at the respective concentrations. The MIC study shows that more than 75% of Enterococcus faecalis growth was inhibited by M-TAP at a concentration of 5 μg/mL, whereas TAP showed inhibition at a concentration of 35 μg/mL. MBC results indicate that almost 99.9% of the bacterial population was killed at a concentration of 100 μg/mL (10-1) for TAP and 10 μg/mL (10-2) for M-TAP.

CONCLUSION

The antibacterial efficacy of M-TAP was significantly higher than TAP. Application of M-TAP at lower doses is advised to overcome the disadvantages seen with TAP.

Antibacterial biofilm efficacy of calcium hydroxide loaded on Gum Arabic nanocarrier: an in-vitro study

BACKGROUND

An innovative intracanal medication formulation was introduced in the current study to improve the calcium hydroxide (Ca(OH)2) therapeutic capability against resistant Enterococcus faecalis (E. faecalis) biofilm. This in-vitro study aimed to prepare, characterize, and evaluate the antibacterial efficiency of Ca(OH)2 loaded on Gum Arabic (GA) nanocarrier (Ca(OH)2-GA NPs) and to compare this efficiency with conventional Ca(OH)2, Ca(OH)2 nanoparticles (NPs), GA, and GA NPs.

MATERIALS AND METHODS

The prepared nanoparticle formulations for the tested medications were characterized using Transmission Electron Microscope (TEM) and Fourier-Transform Infrared Spectroscopy (FTIR). 141 human mandibular premolars were selected, and their root canals were prepared. Twenty-one roots were then sectioned into 42 tooth slices. All prepared root canals (n = 120) and teeth slices (n = 42) were divided into six groups according to the intracanal medication used. E. faecalis was inoculated in the samples for 21 days to form biofilms, and then the corresponding medications were applied for 7 days. After medication application, the residual E. faecalis bacteria were assessed using CFU, Q-PCR, and SEM. Additionally, the effect of Ca(OH)2-GA NPs on E. faecalis biofilm genes (agg, ace, and efaA) was investigated using RT-PCR. Data were statistically analyzed at a 0.05 level of significance.

RESULTS

The synthesis of NPs was confirmed using TEM. The results of the FTIR proved that the Ca(OH)2 was successfully encapsulated in the GA NPs. Ca(OH)2-GA NPs caused a significant reduction in the E. faecalis biofilm gene expression when compared to the control (p < 0.001). There were significant differences in the E. faecalis CFU mean count and CT mean values between the tested groups (p < 0.001) except between the Ca(OH)2 and GA CFU mean count. Ca(OH)2-GA NPs showed the least statistical E. faecalis mean count among other groups. SEM observation showed that E. faecalis biofilm was diminished in all treatment groups, especially in the Ca(OH)2-GA NPS group when compared to the control group.

CONCLUSIONS

Ca(OH)2 and GA nanoparticles demonstrate superior anti-E. faecalis activity when compared to their conventional counterparts. Ca(OH)2-GA NPs showed the best antibacterial efficacy in treating E. faecalis biofilm. The tested NP formulations could be considered as promising intracanal medications.

The Effectiveness of Silver Nanoparticles Mixed with Calcium Hydroxide against Candida albicans: An Ex Vivo Analysis

INTRODUCTION

The purpose of this study was to assess the antifungal activity of silver nanoparticles (AgNPs) in combination with calcium hydroxide (Ca(OH)2) against Candida albicans (C. albicans).

METHODS

AgNPs was mixed with pure Ca(OH)2 powder in an aqueous base. A standard suspension (1 × 108 bacterial cells/mL) of C. albicans was prepared in a 96-well plate and incubated on shaker at 37 °C in 100% humidity to allow fungal biofilm formation in infected dentin slices (n = 98). The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of AgNPs alone or with Ca(OH)2 were determined. The samples were separately placed in 24-well tissue culture plates and divided into three experimental groups (0.03, 0.04, and 0.06) and three control groups; negative (saline) and positive chlorhexidine gel and Ca(OH)2. Quantitative measurements of fungal activity by XTT colorimetric assay and qualitative measurements using confocal laser microscopy and scanning electron microscopy were performed.

RESULTS

The cell viability of C. albicans in the experimental groups was significantly reduced compared to the negative control group. The combination of (AgNPs (0.04%) and Ca(OH)2) was the most potent against C. albicans.

CONCLUSIONS

The findings demonstrated that combining silver nanoparticles with Ca(OH)2 was more effective against C. albicans biofilm compared to Ca(OH)2 alone, suggesting a combing effect.

The effectiveness of single antibiotic paste nitrofurantoin V/S double antibiotic paste in alleviation of post-operative pain of patients suffering from symptomatic irreversible pulpitis-A randomized controlled trial

Objective

The present research evaluated and compared effectiveness between nitrofurantoin and double antibiotic paste in alleviating post-operative pain in patients suffering from symptomatic irreversible pulpitis.

Methods

There were 60 subjects enrolled who were allotted among three groups: Group 1 - Nitrofurantoin, Group 2 - double antibiotic paste, and Group 3 - Control. Succeeding access opening and chemo mechanical preparation, intracanal medicament was placed in the root canals. Using a numerical pain scale, pain scores were measured at the following time intervals: preoperative, 12, 24, 48, and 72 h. One-way ANOVA and post hoc statistical analysis were conducted, with a p-value of ⩽ considered as statistically significant.

Results

Preoperatively, most patients experienced moderate to severe pain. The patients in groups 1 and 2 reported considerable reduction in their pain scores (p ⩽ 0.001) on each time interval. However, patients in group 3 experienced a higher level of pain even at 72 h. No considerable distinction was found among participant's pain scores of groups 1 and 2 (p = 0.193).

Conclusion

For effective pain-relieving, both nitrofurantoin and double antibiotic paste can be successfully used in patients suffering from symptomatic irreversible pulpitis. However, when calcium hydroxide was used, patients experience high levels of pain.

Influence of intracanal medicaments on the periodontal and periapical healing in concurrent endodontic-periodontal lesions with/without communication: a systematic review and meta-analysis

OBJECTIVES

The purpose of this review is to determine the effectiveness of intracanal medicament (ICM) on periodontal and periapical healing (PH) of concurrent endodontic-periodontal lesions with/without communication in permanent teeth.

MATERIALS AND METHODS

The pre-defined protocol was registered in PROSPERO, and a literature search using keywords was conducted on PubMed, Scopus, Cochrane, Embase electronic databases, and Gray literature and was hand-searched until August 2023. Two reviewers independently screened the title and abstracts using the inclusion criteria. Randomized or non-randomized clinical trials, cohort studies, and case-control studies were included in the review. The same reviewers extracted the study-level data and assessed the risk of bias using the Cochrane Risk of Bias 2.0 and the Newcastle-Ottawa Scale (NOS) independently. Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach was used to assess the certainty of evidence. Random effects meta-analysis was performed on eligible studies using Revman software.

RESULTS

A total of 598 records were identified from the database search; seven studies met the inclusion criteria and were included in the review. Four randomized clinical trials, two prospective cohorts, and one retrospective case-control study with 362 patients were included. Calcium hydroxide (CH) was the most commonly used ICM, followed by using chlorhexidine gel in four studies. Periodontal therapy was performed as initial scaling and root planning (SRP) in all studies, along with open flap debridement (OFD) in three randomized clinical trials. The time lapse between two treatment protocols was variable (ranging from 1 week to 3 months). All studies exhibited a decrease in probing depth (PD) and an increase in clinical attachment level (CAL) after the treatment. Meta-analysis showed insignificant differences between different ICM materials, and the certainty of evidence was low.

CONCLUSION

In patients with/without concurrent endodontic-periodontal lesions, intracanal medication improved clinical periodontal parameters following endodontic therapy. In terms of influence on periapical healing, the results were inconclusive.

CLINICAL RELEVANCE

Two-visit RCT may be considered since it allows for the placement of an ICM in endodontic-periodontal lesions with/without communication. Sufficient time should be allowed after endodontic therapy for any potential periodontal regeneration to occur.

Scanning Electron Microscopy Analysis of the Intratubular Radicular Dentin Penetration of Calcium Hydroxide, Triple Antibiotic Paste, and Nitrofurantoin

The aim of this study is to assess and analyze the intratubular penetration of the intracanal medications nitrofurantoin (Nit), triple antibiotic paste (TAP), and calcium hydroxide (CH). Sixty freshly extracted single-rooted teeth were acquired and decoronated to a standard length of 15 mm. To prepare specimens up to size F3, rotary ProTaper instrumentation was employed. The prepared teeth were divided into three groups, each of which received one of the tested intracanal medicaments: Group I (calcium hydroxide), Group II (triple antibiotic paste), and Group III (nitrofurantoin). Using a size #30 Lentulo spiral, a freshly prepared therapeutic paste was placed into the canals, and the intracanal medicaments were allowed to set in the incubator at 100% humidity. The samples were subsequently sliced perpendicularly to their long axis using a precision saw and assessed under a scanning electron microscope to assess the depth of penetration of intracanal medicaments at the coronal, middle, and apical portions of the root canal dentin. The data were analyzed using one-way ANOVA and Tukey's post hoc test. The statistical analysis revealed a significant difference between the experimental groups in the quantity and depth of sealer penetration (p < 0.05). In particular, as compared to the Nit group, both the CH and TAP groups had significantly smaller penetration areas (p < 0.05). In conclusion, this ongoing investigation indicates that nitrofurantoin penetrated dentinal tubules better than calcium hydroxide or triple antibiotic paste.

Antibacterial activity of root canal sealers against established monospecies biofilm: An in vitro study

Endodontic treatment is primarily a combination of chemical as well as mechanical preparation of canal space which helps in the placement of a biocompatible material. The main purpose of endodontic treatment is to eradicate microorganisms from the infected root canal system and prevent recontamination. The principle constituents of an endodontic filling are core material "Gutta Percha" and "Endodontic Sealers." Endodontic sealers should ideally eliminate residual bacteria and prevent reinfection after chemomechanical treatment and obturation of the root canal. The aim of this study is to investigate the antimicrobial effect of four endodontic sealers against bacteria in biofilms commonly detected from persistent and secondary endodontic infections.

Comparative Evaluation of Antimicrobial Efficacy of Various Antibiotic Pastes and Calcium Hydroxide Using Chitosan as a Carrier Against Enterococcus faecalis: An In Vitro Study

INTRODUCTION

The use of intracanal medicaments between appointments can serve as an important aid in the sterilization of the root canal system. Calcium hydroxide is commonly used, but it is not completely effective against Enterococcus faecalis. A triple antibiotic paste (TAP) is used but has the problem of tooth discoloration. Double antibiotic paste (DAP) or modified TAP (MTAP) has been suggested to solve this. Chitosan has been used as a vehicle in pharmacology, and it has inherent antibacterial properties too.

OBJECTIVE

This study compares the efficacy of DAP and MTAP using chitosan as a vehicle with calcium hydroxide.

MATERIALS AND METHODS

Sixty single-rooted teeth were taken and decoronated with a length of 13 mm. Biomechanical preparation (BMP) was done with #3 Gates-Glidden (GG) drills, 17% ethylenediaminetetraacetic acid (EDTA), and 5.25% sodium hypochlorite (NaOCl) used for irrigation. These were kept in microcentrifuge tubes with 1 ml brain heart infusion (BHI) broth. Contamination was done with E. faecalis strain for 21 days. DAP and MTAP pastes were prepared and added to the chitosan solution. Groups were divided into 10 each, each medicament with saline or chitosan as the vehicle. The microbial load was measured at the end of two and seven days.

RESULTS

The level of significance was kept at p = 0.05. Statistical analysis was done with the Kruskal-Wallis test and analysis of variance (ANOVA). DAP and MTAP groups with chitosan showed a significant reduction in the microbial load when compared to calcium hydroxide with chitosan.

CONCLUSION

DAP and MTAP with chitosan can be effective intracanal medicaments against E. faecalis in refractory endodontic cases.

Carbonation inhibitor by polyethylene glycol encapsulation of calcium hydroxide fine particles to improve antimicrobial and root canal penetration properties

The carbonation of calcium hydroxide (Ca(OH)₂) is affected by humidity and a saturated atmosphere. Ca(OH)₂ from nature is easily carbonation and self-aggregates into calcium carbonate (CaCO₃), resulting in larger particle size impairing the antimicrobial properties due to lack of penetration into the dentinal tubules and lower ion dissociation. To reduce the particle size, the wet beads milling process with distilled water as the medium is commonly used, but often results in great carbonation of the final product. Polyethylene Glycol (PEG) may inhibit the carbonation process as well as re-agglomeration. However, it requires intensive drying of the fine Ca(OH)₂ particles. As an alternative, we used ethanol as a medium in the milling process, which is easily dried and compatible with PEG as a surfactant. This study aimed to evaluate PEG 400 as a dispersing agent in ethanol medium in the beads milling process to prevent carbonation of the fine Ca(OH)₂ particles. The following groups were analysed CaP-PEG (Ca(OH)₂-PEG) with ethanol as a medium, CaP-Eth (Ca(OH)₂ with ethanol as a medium), CaP-DW (Ca(OH)₂ with distilled water as a medium), CaPC (Ca(OH)₂-carbonated) as the negative control and CaC (Ca(OH)₂ analytical grade) as the positive control The final particle results were characterized to evaluate the crystal structure, functional groups, and particle size. The corresponding pH and antimicrobial activity against Enterococcus faecalis were assessed at 1, 3, 7, and 14 days. The penetration ability was evaluated by Scanning Electron Microscope. The data obtained were analysed by ANOVA with a significance level of 5%. PEG was able to inhibit carbonation and stabilize pH for up to 14 days, providing increased antimicrobial activity against E. faecalis. PEG also facilitates the ability of fine Ca(OH)₂ particles to penetrate deeper into the dentine tubules by reducing particle size.

Effects of Hypochlorous Acid and Hydrogen Peroxide Treatment on Bacterial Disinfection Treatments in Implantoplasty Procedures

One of the main problems in oral implantology today is peri-implantitis, which affects almost 20% of dental implants placed in patients. One of the most commonly used techniques to eliminate bacterial biofilm is the implantoplasty, that consists of the mechanical modification of the implant surface topography followed by treatments with chemical reagents for decontamination. In this study, the main aim is to evaluate the use of two different chemical treatments based on hypochlorous acid (HClO) and hydrogen peroxide (H₂O₂). For this purpose, 75 titanium grade 3 discs were treated with implantoplasty according to established protocols. Twenty-five discs were used as controls, 25 were treated with concentrated HClO and 25 were treated with concentrated HClO followed by treatment with 6% H₂O₂. The roughness of the discs was determined using the interferometric process. Cytotoxicity with SaOs-2 osteoblastic cells was quantified at 24 and 72 h, whereas bacteria proliferation using S. gordonii and S. oralis bacteria was quantified at 5 s and 1 min of treatment. The results showed an increase in the roughness values, the control discs had an Ra of 0.33 μm and those treated with HClO and H₂O₂ reached 0.68 μm. Cytotoxicity was present at 72 h, together with a significant proliferation of bacteria. These biological and microbiological results can be attributed to the roughness produced by the chemical agents that triggered bacterial adsorption while inhibiting osteoblast adhesion. The results indicate that even if this treatment can decontaminate the titanium surface after implantation, the produced topography will generate an environment that will not favor long-term performance.

In Vivo Assessment of the Calcium Salt-Forming Ability of a New Calcium Silicate-Based Intracanal Medicament: Bio-C Temp

Calcium salt precipitation induced by intracanal medicaments contributes to the formation of apical hard tissue during apexification. This study compared the calcium salt-forming ability of a new calcium silicate-based intracanal medicament (Bio-C Temp) with that of two commercial calcium hydroxide pastes (Calcipex Plane II and Vitapex) in a rat subcutaneous implantation model. Polytetrafluoroethylene tubes containing each of the three materials were subcutaneously implanted in 4-week-old male Wistar rats. After 28 days, the composition and amount of calcium salts formed at the material–tissue interface were assessed using micro-Raman spectroscopy, X-ray diffraction, and elemental mapping. The tested materials produced white precipitates that had Raman spectra with peaks corresponding to hydroxyapatite and calcite. X-ray diffraction detected hydroxyapatite formation on Calcipex Plane II and Vitapex implants, as well as calcite formation on all three materials. Elemental mapping revealed that Bio-C Temp generated significantly smaller calcium- and phosphorus-rich calcified regions within the subcutaneous connective tissue than Vitapex. These results indicate that Bio-C Temp produced less calcium salt in rat subcutaneous tissue than Vitapex, although all materials formed hydroxyapatite and calcite in rat subcutaneous tissue. Bio-C Temp could be less effective than Vitapex in promoting apical hard tissue formation during apexification.

Study on antibacterial properties of heated oyster shell particle against Bacillus subtilis spores in rainwater by response surface methodology based on central composite design

Taiwan's oyster industry produces shell waste in abundant quantities every year. This study explored the feasibility of applying this resource as a simple and low-cost disinfectant to improve the microbial quality of harvested rainwater. Critical parameters affecting the disinfection efficacy of calcined oyster shell particles, i.e., heating temperature and duration, dosage, and contact time of the calcined shell material against Bacillus subtilis endospores in rainwater, were investigated. A central composite design of response surface methodology was employed to study the relative effects. As estimated from R² coefficients, a quadratic model was identified to predict the response variable satisfactorily. Results indicated that the heating temperature, dosage, and contact time of the calcined material in the rainwater significantly influenced (p < 0.05) the sporicidal effect, consistent with the prior literature on calcined shells of similar nature. However, heating time had a relatively low influence on the sporicidal impact, suggesting that the rate of shell activation, i.e., conversion of the carbonate compound in the shell material to oxide, occurs rapidly at high calcination temperatures. In addition, the sterilization kinetics for heated oyster shell particles in aqueous media under stagnant storage conditions were investigated and found to be in good agreement with Hom's model.

Avulsion of Permanent Mandibular Incisors: A Report of Two Cases with Pertinent Literature

Introduction. This study reports two rare cases of avulsion of permanent mandibular incisors with their sequelae after being reimplanted by two contrary methods. The relevant literature regarding the avulsion of permanent mandibular incisors is also being discussed. Case Presentation. In Case I, a 9-year-old girl reported an avulsion of the permanent mandibular left lateral incisor that was immediately reimplanted within 20 minutes after injury, whereas in Case II, all four permanent mandibular incisors were avulsed and reimplanted after a prolonged extraoral dry time of 36 hours in an 18-year-old female. Both cases missed their scheduled follow-up visits and were reported after 3.5 years and 7 months, respectively, with severe root and alveolar bone resorption that was confirmed by clinical examination and Intra oral periapical radiograph (IOPA) radiographs. Discussion. Avulsion of permanent mandibular incisors is rare. The similar unfavorable outcome of contrary cases at a variable duration of time after missed follow-up illustrates the role of the appropriate treatment protocol and regular follow-up visits for the long-term success of reimplanted teeth.

Biodentine Inhibits the Initial Microbial Adhesion of Oral Microbiota In Vivo

This study aimed to evaluate the in vivo initial microbial adhesion of oral microorganisms on the biomaterial Biodentine compared to MTA and AH Plus. Cylindrical samples of the materials were prepared, and dentin slabs served as a control. An individual intraoral lower jaw splint served as a carrier for the samples and was worn by six volunteers. The specimens were worn for 120 min. Adherent bacteria were quantified by determining the colony-forming units (CFUs), while the visualization and quantification of total adherent microorganisms were facilitated by using DAPI and live/dead staining combined with fluorescence microscopy. Bovine dentin had a significantly higher number of aerobic CFUs compared to Biodentine (p = 0.017) and MTA (p = 0.013). The lowest amounts of DAPI-stained adherent microorganisms were quantified for Biodentine (15% ± 9%) and the control (18% ± 9%), while MTA showed the highest counts of initially adherent microorganisms (38% ± 10%). Significant differences were found for MTA and Biodentine (p = 0.004) as well as for MTA and the control (p = 0.021) and for AH Plus and the control (p = 0.025). Biodentine inhibited microbial adherence, thereby yielding an antimicrobial effectivity similar to that of MTA.

Biomimetic Approaches in Clinical Endodontics

In the last few decades, biomimetic concepts have been widely adopted in various biomedical fields, including clinical dentistry. Endodontics is an important sub-branch of dentistry which deals with the different conditions of pulp to prevent tooth loss. Traditionally, common procedures, namely pulp capping, root canal treatment, apexification, and apexigonesis, have been considered for the treatment of different pulp conditions using selected materials. However, clinically to regenerate dental pulp, tissue engineering has been advocated as a feasible approach. Currently, new trends are emerging in terms of regenerative endodontics which have led to the replacement of diseased and non-vital teeth into the functional and healthy dentine-pulp complex. Root- canal therapy is the standard management option when dental pulp is damaged irreversibly. This treatment modality involves soft-tissue removal and then filling that gap through the obturation technique with a synthetic material. The formation of tubular dentine and pulp-like tissue formation occurs when stem cells are transplanted into the root canal with an appropriate scaffold material. To sum up tissue engineering approach includes three components: (1) scaffold, (2) differentiation, growth, and factors, and (3) the recruitment of stem cells within the pulp or from the periapical region. The aim of this paper is to thoroughly review and discuss various pulp-regenerative approaches and materials used in regenerative endodontics which may highlight the current trends and future research prospects in this particular area.

Plasma Rich in Growth Factors in the Treatment of Endodontic Periapical Lesions in Adult Patients: 3-Dimensional Analysis Using Cone-Beam Computed Tomography on the Outcomes of Non-Surgical Endodontic Treatment Using A-PRF+ and Calcium Hydroxide: A Retrospective Cohort Study

The study presents results of periapical lesion healing after one-visit root canal treatment (RCT) with Advanced Platelet Rich Fibrin plus (A-PRF+) application compared to a two-visit RCT with an inter-appointment calcium hydroxide filling. The comparison was made based on CBCT-Periapical Index (PAI) lesion volume changes and the occurrence of post endodontic pain. The results of 3D radiographic healing assessments based on volume reduction criteria were different from the CBCT-PAI. Based on volume changes, the healing assessment criteria-9 cases from the Study Group and six cases in the Control Group were defined as healed. Based on the CBCT-PAI healing assessment criteria, 8 cases from the Study Group and 9 cases from the Control Group were categorized as healed. The volumes of apical radiolucency were, on average, reduced by 85.93% in the Study Group and by 72.31% in the Control Group. Post-endodontic pain occurred more frequently in the Control than in the Study Group. The highest score of pain in the Study Group was five (moderate pain, n = 1), while in the Control Group, the highest score was eight (severe pain, n = 2). In the 6-month follow-up, CBCT scans showed a better healing tendency for patients in the Study Group.

Flavored Food Additives on the Leaves of Piper betle L.: A Human Health Perspective

Natural products and traditional ethnomedicines are of great effect in therapeutics. Such types of medicine have been practiced in certain areas of the world to treat different health conditions. This pilot investigation aims to review the cumulative health effect of addendums used in betel quid such as areca nut, lime, and tobacco-associated betel quid chewing and without tobacco-associated chewing. This review shows that betel leaf extract and its essential oil could inhibit growth of microbes and damage different gram-positive and gram-negative bacteria as well as various fungus species. Some studies concluded that the combination of Piper leaves essential oil with antibiotics have potential effect on oral microorganisms. Long-term consumption of betel quid with tobacco is known to cause cancer, chromosomal aberrations, and pharynx tumors. However, consumption of betel leaf without tobacco has health benefits because of ethnomedicinal properties. Its essential is oil utilized as raw material for perfumes and mouth fresheners manufacturing. Scientific researches on this plant revealed that it possesses many beneficial activities to be used for developing novel drugs. However, compounds of betel leaves have beneficial natural antioxidant. Chewing and intake of leaves have effect on moving parts of salivary gland which is the main step of digestion. Its components also act as heartbeat regulators in relaxing the blood vessels to reduce hypertension. So this review discussed the natural compounds of betel leaves which is used as traditional medicine to further develop drug discovery.

Efficacy of Bioceramic and Calcium Hydroxide-Based Root Canal Sealers against Pathogenic Endodontic Biofilms: An In vitro Study

Background

Complete eradication of root canal pathogens cannot be predictably achieved by chemomechanical preparation and root canal disinfection. Therefore, an obturation material that has superior antimicrobial activity and sealing ability is required to inactivate residual microbes and prevent them from reentering the root canal system. Recently developed bioceramic root canal sealers are hydraulic cement which form calcium hydroxide during the hydration process. Like calcium hydroxide sealers, they exert an antimicrobial effect by releasing hydroxyl ions and increasing the pH.

Objective

The objective of this study was to evaluate and compare the antimicrobial activity of a calcium hydroxide-based sealer and two bioceramic sealers against Porphyromonas gingivalis, Enterococcus faecalis, and Candida albicans biofilms.

Materials and Methods

The sealers were dissolved in sterile saline to obtain supernatants. Biofilm formation assays, colony counting, and real-time polymerase chain reaction (PCR) were performed to evaluate the antimicrobial activity of each supernatant. The data were analyzed using one-way analysis of variance.

Results

All sealers exerted effects against all three microbial biofilms. The biofilm formation assays showed that the bioceramic sealers were more effective against P. gingivalis and E. faecalis biofilms. In contrast, colony counting and real-time PCR showed that the calcium hydroxide sealer was significantly more effective than the bioceramic sealers. All tests showed that the calcium hydroxide sealer was more effective against C. albicans, with the colony count and real-time PCR results showing statistically significant differences.

Conclusion

The calcium hydroxide-based sealer was more effective than the bioceramic sealers in eradicating pathogenic root canal biofilms.

Assessing the Contact Angle Between Dentin Treated With Irrigation and Calcium Hydroxide and Root Canal Sealers

Background

The long-term use of calcium hydroxide, or Ca(OH)2, on dentin has been established in the literature. However, scarce data is available on dentin wettability with Ca(OH)2.

Aim

The present study was conducted to assess the outcomes of Ca(OH)2 use on the wettability of dentin following two and four weeks of using sealers of bioceramic (BC) and Tubli-Seal™ in the root canal.

Methods

In this study, 168 specimens were divided into 12 groups of 14 specimens each and were numbered from G1 to G12. G1-G6 groups were tested with Tubli-Seal. Sterile water irrigation was reserved for G1 for two weeks (14 days) followed by two minutes treatment with 6% sodium hypochlorite (NaOCl) chemical irrigation and 17% EDTA (10 ml). G2 and G3 were subjected to Ca(OH)2 (0.1 ml of UltraCal) for two weeks followed by 10ml sterile water irrigation for two minutes with chemical irrigation. G4 to G6 were given similar treatment for four weeks. G7-G12 were assessed for BC sealer similarly to G1-G6. Two and four weeks of incubation with sterile water or Ca(OH)2 was done in 100% humidity at 37°C. SEM and EDX were done to evaluate the surface morphology of G1 and G6, and results were formed. 

Results

Significantly smaller contact angles were seen for Tubli-Seal (G1 to G6) compared to BC (G7 to G12) with p<0.05. Application of water irrigants and Ca(OH)2 (in G2, G5, and G11) showed a smaller (p<0.05, statistically significant) contact angle compared to the use of chemical irrigation agents and Ca(OH)2 (in G3, G6, and G12) except for G8 and G9. Based on EDX and SEM, compared to the use of chemical irrigation with Ca(OH)2, higher remnants of Ca(OH)2 were seen in the water irrigation, whereas, no remnant was seen with chemical irrigants. 

Conclusion

Better dentin wettability is seen with Tubli-seal compared to BC sealer. A smaller contact angle between root canal sealers and dentin is seen in the remaining calcium hydroxide samples. Also, calcium hydroxide can be removed from the polished dentin surface with two minutes of irrigation with 17% EDTA and 6% NaOCl.

Influence of Filling Material Remnants on the Diffusion of Hydroxyl Ions in Endodontically Retreated Teeth: An Ex Vivo Study

AIM

To assess the influence of remnants of filling material on hydroxyl ion diffusion from calcium hydroxide (CH) paste, measured by the pH value, in retreated teeth.

MATERIALS AND METHODS

A total of 120 single-rooted extracted teeth were prepared up to a size 35 hand file and filled. For retreatment, the specimens were divided into four groups (n = 20): ProTaper Universal Retreatment (PUR), PUR with additional instrumentation (PURA), Mtwo Retreatment (MTWR), and MTWR with additional instrumentation (MTWRA). Negative (NEG) and positive (POS) control groups were composed by 20 specimens each one. The specimens, except NEG, were filled with CH paste. The retreated groups were scanned using cone-beam computed tomography (CBCT) for analysis of filling remnants. The pH assessment was performed at the baseline, after seven, 21, 45, and 60 days of immersion in saline. Data were analyzed using Shapiro-Wilk and Levene's test, followed by a two-way analysis of variance (ANOVA) and Tukey's test.

RESULTS

Additional instrumentation (PURA and MTWRA) were superior regarding removal of the filling material (p <0.05); however, without significant difference (p >0.05). The mean pH value in all groups increased (p <0.05). After 60 days, no statistical difference was observed among POS and PURA; and MTWR and MTWRA. There was less diffusion of hydroxyl ions when the amount of remnants was greater than 59%.

CONCLUSION

Additional instrumentation improved the ability to remove filling material in both systems. All groups presented increasing pH; however, the higher the amount of remnants, the lower the diffusion of hydroxyl ions.

CLINICAL SIGNIFICANCE

The amount of remnants allows less diffusion of calcium hydroxyl ions. Thus, additional instrumentation improves the ability to remove these materials.

Effect of calcium hydroxide on morphology and physicochemical properties of Enterococcus faecalis biofilm

Calcium hydroxide Ca(OH)2 has been used as an intracanal medicament to targets microbial biofilms and avert secondary infection in the root canal system. This study evaluated the effects of this material on the morphology and physicochemical properties of an established in-vitro biofilm of Enterococcus faecalis. A biofilm of E. faecalis was grown in multichannel plates. The chemicals including Ca2+, OH-, and saturated Ca(OH)2 (ie 21.6 mM) were prepared in order to evaluate which component eradicated or amplified biofilm structure. Various biochemical and microscopic methods were used to investigate the properties of the biofilm. Biofilms treated with Ca(OH)2 absorbed more Ca2+ because of the alkaline pH of the environment and the ions affected the physicochemical properties of the E. faecalis biofilm. A denser biofilm with more cavities and a granular surface was observed in the presence of Ca2+ ions. This resulted in a decrease in the surface-to-biofilm ratio with increases in its biomass, thickness, colony size, and volume. Calcium hydroxide did not destroy E. faecalis biofilms but rather contributed to the biofilm structure. This in-vitro study sheds light on a missing link in the formation of E. faecalis biofilm in which the Ca2+ in Ca(OH)2.

Evaluation of Antibacterial and Antifungal Effects of Calcium Hydroxide Mixed with Two Different Essential Oils

BACKGROUND

Calcium hydroxide is a routinely used material for root canal disinfection during root canal treatment. Natural products have great potential in terms of their antibacterial effects. This study aimed to establish an effective alternative intracanal medicament using Origanum dubium (O. dubium) and Mentha spicata (M. spicata) essential oils.

MATERIALS AND METHODS

O. dubium and M. spicata, collected from Lefke, Cyprus, were separately subjected to hydrodistillation. The obtained essential oil compositions were analysed simultaneously by gas chromatography (GC) and gas chromatography/mass spectrometry (GC-MS). The compositions were then divided into groups and mixed with calcium hydroxide at a 1:1 concentration; after that, the pastes were tested on Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans), which are the most common resistant pathogenic microorganisms in the root canal. The antibacterial activity of the pastes was measured using a disk diffusion assay.

RESULTS

The GC and GC-MS analyses revealed that O. dubium and M. spicata had major compositions of carvacrol (75.8%) and carvone (71.3%), respectively. Antimicrobial activity was found to be significantly higher when study groups with O. dubium essential oil were applied to both E. faecalis and C. albicans. The results also show that M. spicata, together with calcium hydroxide, demonstrated a significant antifungal effect on C. albicans when incubated for 72 h.

CONCLUSIONS

M. spicata was found to be an effective antimicrobial agent on C. albicans, whereas O. dubium was found to be very effective on both E. faecalis and C. albicans. These data demonstrate that these natural essential oils may be promising candidates for alternative intracanal medicament in future routine clinical applications.

The Short-Term Antibacterial Activity of Three Selected Endodontic Sealers against Enterococcus faecalis Bacterial Culture

(1) Background: Microorganisms originating from the microflora of the oral cavity are the main cause of the inflammatory diseases of the dental pulp and periapical periodontium, as well as the failure of endodontic treatment. The subsequent root canal treatment is not able to remove all the pathogens, and a small number of viable bacteria remain in the dentine tubules, which must be sealed by endodontic sealers. These sealers should have at least a bacteriostatic effect to prevent the remaining bacteria from reproducing. The aim of this study is to compare the short-term antibacterial activity of three endodontic sealers based on poly-epoxy resin, zinc oxide-eugenol and calcium silicate with a calcium hydroxide-based sealer. Calcium hydroxide is used as temporary intracanal medicament and, thus, should show significant antibacterial activity. (2) Methods: A total of 25 bovine dentine samples infected with Enterococcus faecalis were used in this study. After the sealer placement and a 24 h incubation period, the root canal walls were scraped, and the suspension of dentine fillings was used for a semi-quantitative evaluation of microbial growth. (3) Results: The poly-epoxide resin-based sealer ADSeal™ showed significant antibacterial properties. (4) Conclusions: The highest antibacterial activity was shown in poly-epoxide resin-based sealer group, followed by the zinc oxide-eugenol-based sealer and calcium silicate-based sealer.

Engineering of Injectable Antibiotic-laden Fibrous Microparticles Gelatin Methacryloyl Hydrogel for Endodontic Infection Ablation

This study aimed at engineering cytocompatible and injectable antibiotic-laden fibrous microparticles gelatin methacryloyl (GelMA) hydrogels for endodontic infection ablation. Clindamycin (CLIN) or metronidazole (MET) was added to a polymer solution and electrospun into fibrous mats, which were processed via cryomilling to obtain CLIN- or MET-laden fibrous microparticles. Then, GelMA was modified with CLIN- or MET-laden microparticles or by using equal amounts of each set of fibrous microparticles. Morphological characterization of electrospun fibers and cryomilled particles was performed via scanning electron microscopy (SEM). The experimental hydrogels were further examined for swelling, degradation, and toxicity to dental stem cells, as well as antimicrobial action against endodontic pathogens (agar diffusion) and biofilm inhibition, evaluated both quantitatively (CFU/mL) and qualitatively via confocal laser scanning microscopy (CLSM) and SEM. Data were analyzed using ANOVA and Tukey's test (α = 0.05). The modification of GelMA with antibiotic-laden fibrous microparticles increased the hydrogel swelling ratio and degradation rate. Cell viability was slightly reduced, although without any significant toxicity (cell viability > 50%). All hydrogels containing antibiotic-laden fibrous microparticles displayed antibiofilm effects, with the dentin substrate showing nearly complete elimination of viable bacteria. Altogether, our findings suggest that the engineered injectable antibiotic-laden fibrous microparticles hydrogels hold clinical prospects for endodontic infection ablation.

Local immunomodulatory effects of intracanal medications in apical periodontitis

The immune system is an extremely complex biological network that plays a crucial role in the hemostasis of periapical tissue, pathogenesis of apical periodontitis (AP) as well as periapical tissue healing. The successful elimination of microbial infections remains a significant challenge, mostly due to the ever-growing development of antimicrobial-resistant pathogens. The bacterial endurance in the root canal system contributes to features ranging from altered post-treatment healing to exacerbation of chronic periradicular immune response, that compromise the outcome of endodontic treatment. A highly effective strategy for combating infectious diseases and the associated inflammation-mediated tissue damage is to modulate the host immune response in conjunction with antimicrobial therapy. There are several medications currently used in endodontic treatment, however, they suffer various levels of microbial resistance and do not deliver all the required characteristics to simultaneously address both intracanal bacteria and periapical inflammation. Interaction of antimicrobial agents with the immune system can impact its function, leading to immune-suppressive or immune-stimulatory effects. The group of non-conventional antimicrobial medications, such as antimicrobial peptides, propolis, and nanomaterials, are agents that provide strong antimicrobial effectiveness and concomitant immunomodulatory and/or reparative effect, without any host tissue damages. Herein, we provide an overview of local immune modulation in AP and a comprehensive review of the immunomodulatory effect of antimicrobials intracanal medications applied in endodontics with specific emphasis on the antimicrobial nanomaterial-based approaches that provide immunomodulatory potential for successful clinical deployment in endodontics.

Effect of different intracanal medicaments on the fracture resistance of the human root

Background:

The effect of different intracanal medicaments on root fracture resistance has not been thoroughly investigated in the short and long term. To assess the effect of calcium hydroxide (CH), CH combined with Chlorhexidine (CHX), double antibiotic paste (DAP), and simvastatin as intracanal medicaments on the fracture resistance of the human root. One hundred and twenty single-rooted mandibular premolars which were extracted for periodontal reasons were collected for this in vitro study.

Materials and Methods:

This was an in vitro study. All teeth were decoronated. Root canals were prepared by the Pro taper system, and %2.5 NaOCl was used for irrigation. The smear layer was removed using %5.25 NaOCl and 17% ethylenediaminetetraacetic acid each for 3 min. The samples were randomly divided into five groups based on the medicament: (1) CH (2) CH + CHX (3) Simvastatin (4) DAP (5) Control group. All specimens in each group were incubated for 1 week (Subgroup A) and 1 month (Subgroup B). Then, medicaments were removed and filled with gutta-percha and AH26 sealer. All samples were tested for fracture resistance. The data were statistically evaluated with the SPSS software 17. ANOVA and Mann–Whitney U and Wilcoxon tests were used for the analysis of the data. P = 0.05 was considered statistically significant.

Results:

Although CH and CH + CHX increased the fracture resistance in a 1-week period, there was no significant difference between the groups after 1 month.

Conclusion:

Under the limitations of this study, CH and CH + CHX, DAP and simvastatin do not have a negative effect on root fracture resistance when used as intracanal medicaments for <1 month.

Green synthesis of calcium hydroxide-coated silver nanoparticles using Andrographis paniculata and Ocimum sanctum Linn. leaf extracts: An antimicrobial and cytotoxic activity

Context:

Aim:

Materials and Methods:

Results:

Conclusions:

Efficacy of Oregano Essential Oil Extract in the Inhibition of Bacterial Lipopolysaccharide (LPS)-Induced Osteoclastogenesis Using RAW 264.7 Murine Macrophage Cell Line—An In-Vitro Study

Gram-negative, anaerobic bacterias are predominate in periapical infections. The bacterial lipopolysaccharide (LPS) initiates the process of inflammation and periapical bone resorption. Usage of various medicaments retards or inactivates the bacterial endotoxin (LPS). However, the results are not highly effective. In recent years, owing to antimicrobial resistance, the shift from conventional agents to herbal agents has been increased tremendously in research. Keeping this in mind, the present study was formulated to evaluate the efficacy of oregano essential oil in inhibiting bacterial LPS- induced osteoclastogenesis. Four different concentrations (0 ng/mL, 25 ng/mL, 50 ng/mL, and 100 ng/mL) of oregano essential oil extract were added into 96-well culture plate. Under light microscope, quantification of osteoclast cells was performed. One-way ANOVA with post-hoc Tukey test was carried out on SPSS v21. A significant reduction (p < 0.001) in the osteoclast was observed in the experimental groups compared to no oregano essential oil extract (control). A dose-dependent significant reduction (p < 0.001) in osteoclast formation was observed among the experimental groups, with lesser osteoclast seen in group IV with 100 ng/mL of oregano essential oil extract. Thus, it can be concluded that oregano essential oil extract can be utilized as a therapeutic agent that can target bacterial LPS-induced osteoclastogenesis. However, randomized controlled studies should be conducted to assess the potential use of this extract in the periapical bone resorption of endodontic origin.

The inhibitory effect of a novel neem paste against cariogenic bacteria

Background

Dental caries is a major oral health problem, which associates with cariogenic bacteria. Streptococcus mutans and Lactobacillus acidophilus are facultative anaerobic bacteria that are found in tooth decay. Accordingly, neem leaf extract was developed due to its great anti-microbial property against many bacteria. The aim of this study was to determine anti-cariogenic properties of neem leaf extract in a novel paste preparation.

Material and Methods

The neem extract was derived from maceration of dry neem leaves in ethanol for 48 h. The ethanolic extract was subjected to chemical identification using GC-MS. Neem pastes were prepared from ethanolic extract mixed with polyethylene glycol paste with or without zinc oxide. S. mutans and L. acidophilus test were initiated at bacterial concentration of 108 CFU/ml. The antibacterial activity was then performed by disc diffusion method following by minimum bactericidal concentration (MBC) technique.

Results

GC-MS result displayed 35 compounds. Compounds found in the extract were n-Hexadecanoic acid (31.18%), Hentriacontane (18%), Phytol (16.79%). Disc diffusion showed that ethanolic extract and neem pastes inhibited growth of both bacteria. For MBC, neem paste with zinc oxide at concentration of neem 0.4 mg/ml was the most effective concentration on inhibiting S. mutans growth. Neem pastes and ethanolic extract at concentration of neem 6.25 mg/ml inhibited L. acidophilus growth.

Conclusions

The ethanolic neem leaf extract and novel neem pastes had antimicrobial effect on both S. mutans and L. acidophilus. By this property, neem paste could be developed for the application in dental field, i.e. pulp capping.

Key words:Neem, Azadirachta indica, antimicrobial, cariogenic bacteria.

Influence of the apical limit of instrumentation and photodynamic therapy on the postoperative pain of lower molars with asymptomatic apical periodontitis

INTRODUCTION

The aim of present study was to evaluate the influence of apical limit of instrumentation and PDT on the postoperative pain of lower molars with asymptomatic apical periodontitis.

METHODS

Forty patients were included in the present study and were divided into 4 groups (n=10), according to apical limit of instrumentation and use of PDT: instrumentation at 0.0 measurement; instrumentation at 0.0 measurement+PDT; instrumentation 1mm beyond 0.0 measurement; instrumentation 1mm beyond 0.0 measurement+PDT. In the PDT, the root canals were filled with 0.01% methylene blue, remaining for 5 min. The low-intensity laser was used with 100 mW, 660-690 nm wavelength), using intra-canal fibre. Root canals were irradiated for 90 s, delivering total dose of 9 J and energy density of 320 J/cm2. After root canal preparation and PDT protocols, root canals were filled with gutta-percha and AH Plus endodontic sealer, being sealed with composite resin.The evaluation of postoperative pain was performed by visual analog scale after 24, 48, 72 hours and 7 days. Data were analysed by specific statistical tests, at level of 5%.

RESULTS

No statistical significant difference was observed among experimental groups in all evaluation periods, as well as in the intragroup analysis over time, regarding postoperative pain and analgesic medication consumption (p>0.05).

CONCLUSIONS

Apical limit of instrumentation and PDT have no influence on the postoperative pain of lower molars with asymptomatic apical periodontitis.

Antibacterial Efficacy of Casein Phosphopeptide-Amorphous Calcium Phosphate Compared to Calcium Hydroxide as Intracanal Medicaments against Enterococcus faecalis: In-vitro Study

Background:

Endodontic infection may persist despite root canal instrumentation. Thus, the use of intracanal medicaments plays an essential role in eliminating resistant bacteria like Enterococcus faecalis, known to be associated with persistent infections in endodontically treated teeth. Although calcium hydroxide is the gold standard intracanal medicament, it has been reported that Enterococcus faecalis is immune to its effects. Therefore, several studies assessed the efficacy of other intracanal medicaments, but none to date evaluated Casein Phosphopeptide-Amorphous Calcium Phosphate.

Objectives:

This in-vitro randomized controlled study aimed to assess the antibacterial efficacy of Casein phosphopeptide-amorphous calcium phosphate as an intracanal medicament against Enterococcus faecalis and compared it to calcium hydroxide.

Methods:

60 extracted single root canal permanent teeth were prepared and later divided into three equal groups according to the intracanal medicament used. Group 1: No intracanal medicament (negative control), Group 2: Calcium hydroxide paste, and Group 3: Casein phosphopeptide-amorphous calcium phosphate paste. The intracanal medicaments were placed on the canals for 7 days. The outcome of this procedure was measured by counting colony-forming units. Statistical analysis was carried out using One-Way ANOVA and Tukey’s Post Hoc Test to determine significant differences between the groups.

Results:

The mean bacterial count for Group 2 was significantly lower than Group 1 and Group 3. Calcium hydroxide showed significantly more antibacterial efficacy against Enterococcus faecalis than Casein phosphopeptide-amorphous calcium phosphate and the negative control groups.

Conclusion:

Casein Phosphopeptide-amorphous calcium phosphate is ineffective in inhibiting Enterococcus faecalis growth compared to Calcium hydroxide.

Long-term pH Alterations in the Periradicular Area Following the Application of Calcium Hydroxide and MTA

STATEMENT OF THE PROBLEM

A rise in pH and the presence of calcium ions play an important role in prevention or management of external root resorption.

PURPOSE

This study assessed the long-term pH alterations in the periradicular area following the application of calcium hydroxide (CH) and mineral trioxide aggregate (MTA) intracanal medicaments.

MATERIALS AND METHOD

This in vitro, experimental study evaluated 45 single-canal extracted human teeth. After decoronation and root canal instrumentation, defects (3×3×1mm) were created in the middle third of the roots. Following smear layer removal, the root surface (except for the defect) was sealed with nail varnish. Five teeth served as negative controls and were filled with distilled water. The remaining 40 teeth were randomly divided into two groups (n=20) for application of MTA and CH as intr-acanal medicaments. Periapical radiographs were obtained to ensure optimal quality of obturation. After coronal sealing with glass ionomer, the teeth were incubated at 37°C, and their pH was measured at 1 and 2 weeks, and 1 and 3 months, using a pH-meter. Data were analyzed using one-way ANOVA, Tukey's test and Bonferroni adjustment.

RESULTS

The mean pH was significantly higher in CH group at 1 and 2 weeks (p< 0.01) but no difference was noted at 1 and 3 months (p= 0.52). The mean pH in both groups was significantly higher at 2 weeks compared with other time points (p< 0.05).

CONCLUSION

CH may be preferred for use in the first weeks following the initiation of root resorption to provide a high pH. MTA can be later applied to maintain the high pH for a longer period of time without the need for medicament exchange.

Synthesis, Characterization, and Antibacterial Evaluation of a Cost-Effective Endodontic Sealer Based on Tricalcium Silicate-White Portland Cement

Mineral trioxide aggregate (MTA) is an ideal yet costly endodontic sealer material. Tricalcium silicate-white Portland cement (TS-WPC) seems to have similar characteristics to those of MTA. This work aims to characterize a modified TS-WPC and evaluate its antibacterial properties as a potential endodontic sealer material. The modified TS-WPC was synthesized from a 4:1 mixture of sterilized Indocement TS-WPC and bismuth trioxide using a simple solution method with 99.9% isopropanol. The mixture was stirred until it was homogenous, centrifuged, and dried. The material was then characterized using infrared spectroscopy, X-ray diffraction, and electron microscopy and subjected to antibacterial evaluation against Enterococcus faecalis using a Mueller-Hinton agar inhibition test. The results showed that the material was characterized by main functional groups of hydroxyls, silicate, bismuth trioxide, and tricalcium silicate, like those of a commercial MTA-based sealer, both tested after hydration. Modified TS-WPC before hydration showed similar powder morphology and size to the commercial one, indicating the ease of manipulation. Both materials exhibited antibacterial activity due to calcium dihydroxide's ability to absorb carbon dioxide, which is essential for the anaerobic E. faecalis, with minimum inhibitory effect and bactericidal concentrations of 12,500 ppm and 25,000 ppm, respectively. The modified TS-WPC has the potential to become a cost-effective alternative endodontic sealer material.

Antimicrobial Efficacy of Intracanal Medicaments against E. Faecalis Bacteria in Infected Primary Molars by Using Real-Time PCR: A Randomized Clinical Trial

Aim

This study aimed to compare the antimicrobial efficacy of calcium hydroxide (CH) and triple antibiotic paste (TAP) against E. faecalis bacteria in infected primary molars.

Methods and Materials

Thirty-nine 4–6-year-old children with an infected primary molar were randomly divided into three equal groups (n = 13) to receive either CH or TAP and an untreated control group. Following access cavity preparation, the first microbiological samples (S1) were collected by using absorbent paper points. The canals were prepared and rinsed. Then, CH or TAP was applied in the root canals. Seven days later, the second microbiological samples (S2) were collected. DNA extraction was performed to count E. faecalis bacteria by using real-time PCR for S1 and S2 samples. Data were analyzed through one-way ANOVA and Tukey's test (α = 0.05).

Results

E. faecalis bacteria counts decreased significantly in CH and TAP groups compared with the control group (P ≤ 0.001). However, no statistically significant difference existed between these two groups (P=0.698).

Conclusion

Both TAP and CH have significant antimicrobial effects as intracanal medicament between the treatment sessions in infected primary teeth.

Photosensitizers attenuate LPS-induced inflammation: implications in dentistry and general health

Antimicrobial photodynamic therapy (aPDT) is a complementary therapeutic modality for periodontal and endodontic diseases, in which Gram-negative bacteria are directly involved. Currently, there are few evidences regarding the effects of aPDT on bacterial components such as lipopolysaccharide (LPS) and it would represent a major step forward in the clinical use of this therapy. In this context, this study aimed to evaluate the efficacy of different photosensitizers (PSs) used in aPDT in LPS inhibition. Four PSs were used in this study: methylene blue (MB), toluidine blue (TBO), new methylene blue (NMB), and curcumin (CUR). Different approaches to evaluate LPS interaction with PSs were used, such as spectrophotometry, Limulus amebocyte lysate (LAL) test, functional assays using mouse macrophages, and an in vivo model of LPS injection. Spectrophotometry showed that LPS decreased the absorbance of all PSs used, indicating interactions between the two species. LAL assay revealed significant differences in LPS concentrations upon pre-incubation with the different PSs. Interestingly, the inflammatory potential of LPS decreased after previous treatment with the four PSs, resulting in decreased secretion of inflammatory cytokines by macrophages. In vivo, pre-incubating curcumin with LPS prevented animals from undergoing septic shock within the established time. Using relevant models to study the inflammatory activity of LPS, we found that all PSs used in this work decreased LPS-induced inflammation, with a more striking effect observed for NMB and curcumin. These data advance the understanding of the mechanisms of LPS inhibition by PSs.

Needle-injectable microcomposite cryogel scaffolds with antimicrobial properties

Porous three-dimensional hydrogel scaffolds have an exquisite ability to promote tissue repair. However, because of their high water content and invasive nature during surgical implantation, hydrogels are at an increased risk of bacterial infection. Recently, we have developed elastic biomimetic cryogels, an advanced type of polymeric hydrogel, that are syringe-deliverable through hypodermic needles. These needle-injectable cryogels have unique properties, including large and interconnected pores, mechanical robustness, and shape-memory. Like hydrogels, cryogels are also susceptible to colonization by microbial pathogens. To that end, our minimally invasive cryogels have been engineered to address this challenge. Specifically, we hybridized the cryogels with calcium peroxide microparticles to controllably produce bactericidal hydrogen peroxide. Our novel microcomposite cryogels exhibit antimicrobial properties and inhibit antibiotic-resistant bacteria (MRSA and Pseudomonas aeruginosa), the most common cause of biomaterial implant failure in modern medicine. Moreover, the cryogels showed negligible cytotoxicity toward murine fibroblasts and prevented activation of primary bone marrow-derived dendritic cells ex vivo. Finally, in vivo data suggested tissue integration, biodegradation, and minimal host inflammatory responses when the antimicrobial cryogels, even when purposely contaminated with bacteria, were subcutaneously injected in mice. Collectively, these needle-injectable microcomposite cryogels show great promise for biomedical applications, especially in tissue engineering and regenerative medicine.

The efficacy of a traditional medicine preparation on second-degree burn wounds in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Lime Salve (L.S) has been well documented from the 9th to the 19th century AD by traditional Iranian medicine (TIM) as an effective remedy for burn healing.

AIM OF THE STUDY

The present study was undertaken to evaluate the healing effect and related underlying mechanisms of Lime Salve in a model of deep second-degree thermal burn in male Wistar rats.

MATERIALS AND METHOD

L.S was made up of a combination of refined calcium hydroxide powder, beeswax and sesame oil and its quality control was assessed. A deep second-degree burn was created by a hot plate in 48 male Wistar rats. Afterwards, they were randomly divided into four groups including normal saline (C group), L.S (T group), basement of formulation composed of beeswax and sesame oil (B group) and silver sulfadiazine (S group). On days 5, 10, 17 and 24, the wounds were digitally photographed by a camera and after sacrifice of the rats, skin samples were obtained for performing qRT-PCR, immunohistochemistry staining and histological examination.

RESULTS

L.S prominently augmented the wound closure rate, neovascularization on day 10 and collagen formation on days 17 and 24 in comparison with the C group. Furthermore, the Salve-exposed specimens showed a significant higher epithelialization during the experiment with a peak on day 24. qRT-PCR also showed that on day 10, VEGF and TGF-β1 genes were significantly higher in the T group as compared with the C group. Also, MMP-9 and MMP-2 genes had a significant peak of expression on day 17 and rapid reduction of expression on day 24. Expression levels of IL-6 and TNF-α genes peaked on day 10 in the T group, followed by a progressive reduction until the end of the examination.

CONCLUSION

L.S could effectively accelerate the healing process of deep second-degree burn wounds and therefore, it may be recommended as a promising topical medication for treating burn wounds in the future clinical trials.

Antibiofilm and Immune Response of Engineered Bioactive Nanoparticles for Endodontic Disinfection

The biological aim of root canal treatment is to facilitate periapical tissue healing following endodontic therapy. This study aimed to develop an organotypic infected root canal model to understand the interaction of bacterial biofilm with macrophages and study the therapeutic effect of engineered bioactive chitosan nanoparticles (CSnp) on macrophages. Ex-vivo experiments were conducted in two phases; Phase-1: Enterococcus faecalis biofilms (two and six weeks old) developed in organotypic root canal model were used to characterize residual biofilm after conventional chemical treatment alone and combined with CSnp utilizing Confocal Laser Scanning Microscopy, Scanning Electron Microscopy and colony-forming units from pulverized dentin. Phase-2: The interaction of post-treatment biofilm and RAW macrophages was evaluated regarding pro/anti-inflammatory markers, cell viability and spreading at 24, 48 and 72 h. Compared to conventionally disinfected six-week-old biofilm, CSnp resulted in less viable bacteria (p < 0.01). Scanning electron micrographs demonstrated disruption of the biofilm. CSnp exhibited less residual bacterial load in pulverized dentin (p < 0.001). Macrophage interaction with CSnp-treated biofilm reduced proinflammatory markers (nitric oxide, TNF-α, IL-1β, and IL-6), increased anti-inflammatory marker (TGF-β1) and enhanced cell survival and spreading over time (p < 0.01 at 72 h). Engineered chitosan nanoparticles concurrently inactivated biofilm and altered the inflammatory response of macrophages that would promote healing.

Virucidal Efficacy of a Quaternary Ammonium Compound with Food Additive-Grade Calcium Hydroxide Toward Avian Influenza Virus and Newcastle Disease Virus on Abiotic Carriers

The virucidal efficacies of a 0.2% food additive-grade calcium hydroxide [FdCa(OH)₂] solution, a quaternary ammonium compound (QAC) diluted at 1:500 (QACx500), and their mixture [Mix500; FdCa(OH)₂ powder added at a final concentration of 0.2% to QACx500] were investigated as fomites for avian influenza virus (AIV) and Newcastle disease virus (NDV) on abiotic carriers (steel, rubber, and plastic) at two different temperatures (room temperature [RT; 25 ± 2 C] and 2 C). These viruses were seeded on coupons (5 cm×5 cm) of rubber, steel, or plastic with 5% fetal bovine serum. After complete drying, the coupons were covered with the test solutions at RT or 2 C. After fixed incubation periods, viruses were recovered from the coupons and titrated. At RT, Mix500 required a short time (3 min) to inactivate AIV and NDV to effective levels (≥3 log virus reduction) on rubber, steel, and plastic carriers compared with QAC or FdCa(OH)_2. At low temperature, QACx500 inactivated AIV on steel and plastic carriers to effective levels within 60 min, whereas Mix500 did so within 10 min. QACx500 and FdCa(OH)₂ solutions could inactivate NDV on steel and plastic carriers within 20 and 10 min, respectively, and Mix500 could do so within 3 min. Viruses on the carriers required longer incubation periods for inactivation at 2 C than at 25 C. These results demonstrate desirable synergistic virucidal effects of Mix500 for important poultry viruses on abiotic carriers, while indicating high applicability within poultry farming.

Diffusion of calcium hydroxide through dentinal tubules of retreated root canals: An in vitro study

Objective:

Studies about the dispersion of hydroxyl ions through dentin of endodontically retreated teeth are scarce. The present study aims at examining the diffusion of calcium hydroxide in vitro by recording the pH changes of retreated root canal using two types of calcium hydroxide preparations.

Materials and Methods:

A total of 45 recently extracted single-rooted mandibular first premolars were collected and cleaned from calculus and remains of periodontal tissue. The teeth so collected were stored in thymol 10% solution till use. During collection, teeth with cracks, open apices, and restorations were excluded. Root canal preparations were performed using Protaper rotary system files, till #F3 file. All canals were obturated using cold lateral condensation and zinc oxide-based sealer. After 7 days, all gutta-percha were removed and the canals were irrigated with normal saline. The teeth were then randomly distributed into three groups. Canals in Group I were kept empty without any dressing to serve as a negative control group, Canals in Group II were filled with a freshly prepared mixture of calcium hydroxide powder with normal saline solution, and Group III was filled with Metapex. Periodically, the calcium hydroxide material was removed and the pH was measured using pH meter at 7, 10, 14, and 30 days.

Results:

The pH values of Group II and III ranged between 9.2 and 11.2. This was found to be highly significant against the negative control group. After 7 and 10 days, freshly mixed Ca(OH)₂ showed the higher pH than the creamy Metapex, and statistically the difference was highly significant after 10 days (P<0.001). After 14 days, Metapex group pH was higher than freshly mixed Ca(OH)₂, but it was not statistically significant as they reached nearly the same pH after 30 days (P>0.05).

Conclusion:

All Ca(OH)₂ preparations had high pH around the roots after 7 and 10 days. Metapex continued to have higher pH after 14 days.