This study evaluated whether preoperative alpha brain wave activity measured using electroencephalography is associated with postoperative pain intensity after single-visit endodontic treatment in patients with symptomatic irreversible pulpitis. One hundred healthy adults with symptomatic irreversible pulpitis in mandibular first molars were included. Preoperative alpha brain wave activity was recorded before treatment. All patients received standardized single-visit root canal treatment. Pain intensity was recorded using a visual analog scale preoperatively and at 6, 24, 48, and 72 h postoperatively. Correlations between alpha power and pain scores were analyzed using Spearman rank-order correlation. Associations with gender and changes in pain over time were also assessed. Postoperative pain decreased significantly from 24 h onward (24 h, p < 0.05; 48 h, p < 0.0001; 72 h, p < 0.0001). Higher preoperative alpha brain wave activity was associated with lower postoperative pain scores. In the overall sample, negative correlations were observed at 6 h (p < 0.05, r = -0.247), 24 h (p < 0.001, r = -0.321), 48 h (p < 0.001, r = -0.321), and 72 h (p < 0.001, r = -0.336), as well as for median postoperative pain scores (p < 0.01, r = -0.309). Females reported higher preoperative pain scores (p < 0.05), but no significant gender differences were observed postoperatively. Subgroup analysis showed variation in the timing of significant correlations between males and females. Preoperative alpha brain wave activity was associated with postoperative pain intensity after root canal treatment. These exploratory findings suggest that resting neural activity may reflect individual variation in pain susceptibility, although the reported p-values are unadjusted for multiple comparisons and require external validation.

Background: Endodontic diagnosis usually assumes that pain, tenderness, swelling, sensibility test responses, and radiographic change reflect the interaction between microbial irritation and host response. Under altered host immunity, this relationship becomes less predictable because disease activity and disease expression may no longer progress in parallel. Biologically important pulpal or periapical disease may therefore appear deceptively mild, whereas competing oral or systemic conditions may complicate localization and interpretation. Objectives: To examine how altered host immunity changes the diagnostic expression of pulpal and periapical disease, distinguish immune suppression from immune dysregulation as biologically distinct states, and propose a practical clinical approach to diagnostic uncertainty in these patients. Methods: A narrative review with structured integrative synthesis was conducted. PubMed/MEDLINE and Scopus were searched from database inception to April 2026, with reference-list screening of relevant reviews, clinical studies, and mechanistic papers. Search terms combined altered host immunity, immune suppression, immune dysregulation, autoimmune disease, immunomodulatory therapy, pulpitis, apical periodontitis, root canal treatment, endodontic diagnosis, pain, inflammation, imaging, and pulp sensibility. Sources were selected when they informed diagnostic expression, symptom interpretation, clinical test reliability, radiographic assessment, or practical decision-making. Evidence was grouped by immune suppression, immune dysregulation, and overlap states, then synthesized into a diagnostic framework. Results: Altered host immunity changed the diagnostic meaning of conventional endodontic findings in two broad directions. Immune suppression tended to attenuate inflammatory expression, with reduced pain, swelling, and delayed radiographic change, thereby increasing the risk of under-recognition. Immune dysregulation tended to reduce interpretive clarity through chronic inflammatory activity, mucosal disease, xerostomia, neuropathic overlap, and treatment-related oral change, thereby increasing the risk of misdirection or misdiagnosis. Conventional tests retained clinical value, but isolated interpretation became less secure. A practical five-step response was therefore proposed: define the immune context, classify the presentation pattern, interpret findings together, escalate imaging when needed, and recognize red flags early. Conclusion: Altered host immunity does not invalidate conventional endodontic diagnosis. However, it requires more cautious and context-sensitive interpretation. Safer diagnosis depends on integration of medical history, tooth-specific examination, imaging, and reassessment over time, together with patience and empathy when uncertainty persists.

Background: Contemporary deep and extremely deep caries management increasingly favors selective or stepwise excavation because these strategies reduce pulpal exposure and preserve tooth structure. However, clinical survival is often interpreted beyond its biological meaning. Objective: This perspective examines why asymptomatic tooth survival, retained sensibility, absence of radiographic disease, and lack of retreatment are incomplete markers of pulpal health. Evidence synthesis: Randomized clinical trials are essential for comparing caries removal strategies and estimating outcomes such as exposure, pain, restoration failure, retreatment, and tooth loss. These endpoints have clinical and patient-centered value. However, they do not directly measure residual bacterial viability, inflammatory status, vascular vitality, focal necrosis, pulp stem cell function, or true tissue healing. Histopathological, histobacteriological, microbiological, biomarker, and imaging evidence indicate that clinically silent teeth may still contain bacterial penetration, chronic inflammation, altered cellular phenotype, and reduced repair capacity. Selective excavation should therefore be viewed as a toothpreserving intervention with variable biological meaning instead of direct proof of pulpal recovery. The paper also reframes pulp exposure as more than a procedural complication. In selected cases, exposure may disclose tissue status through bleeding quality, hemostasis, tissue color, and necrotic changes, thereby informing vital pulp therapy. Conclusions: Pulp conservation requires an evidence model that separates clinical success, diagnostic stability, biological recovery, and long-term disease control. Randomized trials should be interpreted along with tissue-level, mechanism-level, diagnostic, patient-reported, economic, and long-term outcomes. Lesion depth, restoration quality, and study settings also matter. The goal of deep caries management should be survival with health, not survival alone.

OBJECTIVES: This research evaluated the success rates of pulpotomy, compared its efficacy with non-surgical root canal treatment (NSRCT), analyzed various pulpotomy techniques, and assessed the effectiveness of contemporary bioactive materials for managing irreversible pulpitis in mature permanent teeth. METHODS: A comprehensive literature search was conducted across databases, including PubMed, Web of Science, Scopus, and the Cochrane Library, adhering to PRISMA 2020 guidelines. Studies were selected through a multi-step screening process, focusing on adult populations, randomized controlled trials, and single-arm trials. RESULTS: A total of fifteen randomized controlled trials and eight single-arm trials were included. The pooled clinical success rate of pulpotomy was 92.9% (95% CI; 82.1–99.0%) for follow-ups over 24 months, while the pooled radiographic success rate was 78.5% (95% CI; 66.7–88.4%). Meta-analyses showed no significant differences in success rates among pulpotomy and NSRCT, between full and partial pulpotomy techniques, or between Mineral Trioxide Aggregate and Calcium Enriched Mixture pulpotomy, indicating comparable efficacy across these variables. CONCLUSIONS: The findings highlight the potential of less invasive treatments, suggesting pulpotomy as a viable alternative to NSRCT for managing irreversible pulpitis in mature teeth. Limitations, such as varying trial quality and bias in some studies, emphasize the need for further research to standardize methodologies and enhance the understanding of pulpotomy efficacy. Future studies should focus on standardized protocols to validate these findings and improve patient treatment outcomes.

OBJECTIVES:This review examined the roles of ion channels in dentine hypersensitivity (DH), highlighting their contributions to pain perception and intercellular communication between odontoblasts and afferent sensory neurons. BACKGROUND:Dentine hypersensitivity is a prevalent condition resulting from the exposure of dentinal tubules to the oral environment, leading to sharp pain triggered by mechanical, thermal, chemical, and osmotic stimuli. The prevailing hypothesis integrates aspects of the hydrodynamic and odontoblast transducer theories. It suggests that rapid intratubular fluid movement activates specific ion channels in odontoblasts and trigeminal sensory neurons, converting external stimuli into electrical signals interpreted as pain by the central nervous system. DATA & SOURCES:A comprehensive literature review was conducted on ion channels involved in DH, with a focus on transient receptor potential (TRP) channels, Piezo channels, acid-sensing ion channels (ASICs), as well as other voltage-gated ion channels. Particular emphasis was placed on their physiological roles, responsiveness to stimuli, and contributions to DH pain. RESULTS:PIEZO, TRP, and ASICs respond to pressure, heat, acidic environments, and chemical irritants, all of which contribute to DH pain. Activation of odontoblastic ion channels results in the release of adenosine triphosphate and glutamate, which bind respectively to purinergic and glutamate receptors on sensory neurons. This interaction induces depolarization, generating action potentials that transmit pain signals to the brain. CONCLUSION:The diverse ion channels involved in dentine hypersensitivity play a crucial role in intercellular communication that leads to pain perception. However, their widespread physiological functions make direct pharmacological targeting challenging due to potential systemic effects. CLINICAL SIGNIFICANCE:The use of antagonists for targeting specific ion channels involved in dentine hypersensitivity is difficult because of their involvement in other important physiological processes. Hence, clinical management strategies focusing on dentinal tubule occlusion or dentine desensitisation remain the safest and most effective approaches.

OBJECTIVES:This study evaluated the effect of apical negative pressure sealer infiltration on void percentage, void types, porosity size distribution, and coronal microleakage in root canal fillings using different hydraulic calcium silicate sealers with the single-cone technique. METHODS:Forty-eight extracted premolars with long oval-shaped canals were selected and divided into four groups based on the filling technique and sealer (n = 12): apical negative pressure-assisted NeoSEALER Flo (NPNF), apical negative pressure-assisted iRoot SP (NPS), syringe-assisted NeoSEALER Flo (SNF), and syringe-assisted iRoot SP (SS), all using the single-cone technique. Micro-computed tomography (10 µm resolution) was used to scan the obturated canals. Void percentages, types, and porosity size distribution were analyzed. Statistical significance was set at α = 0.05. RESULTS:None of the techniques yielded void-free obturations. However, the NPNF (0.75 %, interquartile range 0.93 %) and NPS (0.42 %, IQR 0.68 %) groups showed significantly lower overall void percentages than the SNF (13.27 %, IQR 9.24 %) and SS (15.39 %, IQR 13.87 %) groups (p < 0.05). No significant difference was identified between the NPNF and NPS groups, or between the SNF and SS groups. Apical negative pressure groups also demonstrated significantly fewer open voids and large porosities and reduced microleakage compared to the syringe-assisted groups (p < 0.05). CONCLUSION:Apical negative pressure sealer infiltration combined with the single-cone technique significantly improved filling quality and reduced coronal microleakage in long oval-shaped root canals compared to the conventional syringe-assisted single-cone technique. CLINICAL: SIGNIFICANCE:The use of apical negative pressure for introducing hydraulic calcium silicate sealers during single-cone obturation improves the quality of root canal fillings by reducing the percentage of voids and the presence of large porosities.

OBJECTIVES:To evaluate the mechanical properties of root canal dentin treated with sodium hypochlorite (NaOCl) in combination with hydroxyethylidene diphosphonic acid (HEDP) or ethylenediaminetetraacetic acid (EDTA). METHODS:For testing fracture resistance, 45 single-rooted teeth were instrumented and irrigated with NaOCl/HEDP, NaOCl/EDTA, or distilled water. Fifteen untreated teeth served as control. After obturation, specimens from the experimental groups were thermocycled, dynamically-loaded, and then statically-loaded in a universal testing machine until failure. For flexural strength analysis, 15 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Root segments were sectioned into dentin bars and tested for flexural strength using a universal testing machine. For microhardness evaluation, 20 teeth were instrumented and irrigated with NaOCl/HEDP or NaOCl/EDTA. Dentin disks from the coronal-third of each root segment were prepared, one before and one after irrigation, for microhardness testing with a Knoop hardness tester. RESULTS:The highest fracture resistance was recorded in the untreated group, and the lowest in the EDTA group. Although the HEDP group had higher fracture resistance than the EDTA group, the distilled water group demonstrated even greater fracture resistance than the HEDP group. Specimens treated with HEDP had significantly higher flexural strength and microhardness values when compared with those treated with EDTA. CONCLUSION:The fracture resistance, flexural strength, and microhardness of root canal dentin were higher when root canals were irrigated with NaOCl/HEDP, when compared with NaOCl/EDTA. CLINICAL SIGNIFICANCE:Irrigating root canals with NaOCl combined with HEDP significantly improves the mechanical integrity of root canal dentin compared to the use of NaOCl with EDTA.

Objectives This quantitative systematic review evaluated whether pulpotomy performed with hydraulic calcium silicate cements may be used as an alternative to root canal treatment (RCT) in mature permanent teeth with carious pulp exposure. Data sources A comprehensive search was conducted in PubMed, Web of Science, Scopus, and the Cochrane Library. No language restrictions were applied. The search included randomised controlled trials that compared pulpotomy to root canal treatment for managing carious exposure in mature permanent teeth. Study selection Studies were selected based on predetermined inclusion criteria: randomised controlled trials involving mature permanent teeth with carious pulp exposure, using hydraulic calcium silicate cements for pulpotomy. Non-comparative studies, case reports, and trials involving primary or immature permanent teeth were excluded. Data Data were extracted on success rates, clinical outcomes, follow-up periods, pain profiles, and potential complications. A meta-analysis was performed, revealing no statistically significant differences in success rates between pulpotomy and RCT. Both interventions demonstrated success rates exceeding 90 % at one-year and two-year follow-up periods. Pain profiles consistently showed lower post-operative pain intensity in the pulpotomy group compared to the RCT group during the first week. Potential complications, such as non-responsive pulp and difficulties in determining pulp vitality, were reported more frequently in the pulpotomy group. Conclusions Pulpotomy with bioactive hydraulic calcium silicate cements shows comparable success rates to RCT in managing carious pulp exposure in mature permanent teeth. The results suggest pulpotomy as a viable, less invasive alternative to RCT, particularly in cases where preservation of pulp vitality is paramount. Clinical significance This systematic review highlights pulpotomy as a less invasive and cost-effective alternative to root canal treatment in mature permanent teeth. With comparable success rates and lower post-operative pain, pulpotomy offers a promising approach to managing carious exposure and preserving tooth vitality.

Objectives : This paper evaluated the success rates of pulpotomy, compared its efficacy with non-surgical root canal treatment (NSRCT), evaluated different pulpotomy techniques, and analyzed the effectiveness of contemporary bioactive materials in managing irreversible pulpitis in mature permanent teeth. Data Sources A comprehensive literature search was conducted across multiple databases including PubMed, Web of Science, Scopus, and the Cochrane Library. Search was conducted from the inception of each database to the present, adhering to PRISMA 2020 guidelines. Study Selection Studies were selected through a multi-step screening process, focusing on adult populations, randomized controlled trials, and single-arm trials. Data Fifteen randomized controlled trials and eight single-arm trials were included. For a follow-up period of more than 24 months, pooled clinical success rate of pulpotomy was 92.9% (95%CI;82.1-99.0%), whereas pooled radiographic success rate was 78.5% (95%CI;66.7-88.4%). Meta-analyses showed that there was no significant difference in success rates between pulpotomy and NSRCT, between full and partial pulpotomy techniques, or between Mineral Trioxide Aggregate pulpotomy and Calcium Enriched Mixture pulpotomy. The results indicated comparable efficacy across these variables. Conclusions: The study highlights the potential of less invasive treatments. Pulpotomy may be a viable alternative to NSRCT for managing irreversible pulpitis in mature permanent teeth. Limitations such as the low quality of some single-arm trials and the high risk of bias in some randomized controlled trials highlight the need for further research to standardize methodologies and broaden literature inclusion for a more comprehensive understanding of the efficacy of pulpotomy, considering the high success rates reported.Clinical Significance: This quantitative systematic review recognizes the potential of full or partial pulpotomy as a viable treatment alternative to root canal therapy for managing irreversible pulpitis in mature permanent teeth. Future studies should aim for standardized protocols to validate these findings and improve patient treatment outcomes.

OBJECTIVES:The present review discussed the biomechanical properties of cracks and fractures in crown and root dentine and attempted to explain why cracked teeth and vertical root fractures are so frequent despite the existence of multiple crack toughening mechanisms in dentine. The implications of this knowledge were used to justify how these defects are managed clinically.DATA, SOURCES AND STUDY SELECTION:Literature search was conducted on PubMed, Web of Science, and Scopus for a narrative review on fracture mechanics of crown and root dentine as well as the clinical management of cracked teeth and teeth with vertical root fracture.CONCLUSIONS:Although dentine is tougher and less brittle than enamel, it's facture toughness is considerably lower than most ductile metals. Because the initiation toughness of dentine is very low, cracks initiate from incipient damage under low stress While crack toughening mechanisms exist that enable dentine to resist crack extension, these mechanisms are often inadequate for protecting dentine from crack propagation that ultimately leads to catastrophic failure. Additional factors such as ageing also reduces the resistance of dentine to crack growth. Because dentine cracks are eventually filled with bacteria biofilms upon exposure to oral fluids, they enable rapid bacteria ingress into the dental pulp via open dentinal tubules. To date, treatment options for cracked teeth are limited. While most teeth with vertical root fracture are recommended for extraction, new strategies have been reported that appeared to achieve short-term success in preserving these teeth.CLINICAL SIGNIFICANCE:Current strategies for the management for dentine cracks and fractures are limited and their long-term effectiveness remain uncertain. Understanding the characteristics, toughening mechanism and weakening factors of tooth cracks is helpful in designing better treatment.

OBJECTIVES: To evaluate the bacterial debridement efficacy of two generations of sonic root canal irrigant activation systems: EndoActivator (the first generation) and SmartLite Pro EndoActivator (the second generation). METHODS: Instrumented, autoclaved, single-rooted human premolars were inoculated with Enterococcus faecalis for 21 days. The bacteria biofilm-containing teeth were randomly divided into 5 groups (N=8): Group 1: Syringe-side-vented needle (S-N) delivery of saline for 1 min; Group 2: S-N delivery of 2% NaOCl for 1 min; Group 3: S-N delivery of 2% NaOCl for 5 min; Group 4: EndoActivator activation of 2% NaOCl for 1 min; Group 5: Smartlite Pro EndoActivator activation of 2% NaOCl for 1 min. The teeth were evaluated for bacterial reduction using CFU counts. The percentages of dead bacteria within dentinal tubules were determined using confocal laser scanning microscopy. RESULTS: Activation of NaOCl with EndoActivator or Smartlite Pro EndoActivator significantly reduced the overall intracanal bacterial load, compared with S-N irrigant delivery (P<0.05). There was no significant difference between the two agitation devices (P>0.05). Nevertheless, S-N delivery of 2% NaOCl for 5 min produced better bacteria debridement than either sonic agitation system. Different degrees of bacterial kill were identified in the coronal-middle and apical portions of the canal space. Conclusion: Delivery time of NaOCl affects the efficacy of bacterial disinfection. Activation with the EndoActivator or SmartLite Pro EndoActivator for 1 min demonstrated comparable canal wall biofilm and intracanal bacteria reduction efficacy when 2% NaOCl was used as irrigant for disinfection E. faecalis in single-rooted teeth.

OBJECTIVES:To examine the efficacy of glycine powder air-polishing on cleaning root canal sealer-smeared dentine.METHODS:Dentine surfaces were contaminated with a smear of epoxy resin-based sealer or tricalcium silicate-based sealer. The contaminated surfaces were cleaned with saline, 75% ethanol, or air-polishing with glycine powder. Uncontaminated dentine was used as the control. The cleanliness of pulpal floor dentine was examined using scanning electron microscopy and energy dispersive X-ray analysis. The effectiveness of the three cleaning protocols was examined by testing the tensile bond strength of a self-etching adhesive to the decontaminated dentine. Resin infiltration into the dentinal tubules was identified using confocal laser scanning microscopy (CLSM).RESULTS:Morphological examination and elemental analysis indicated that glycine powder air-polishing was more effective in removing the two sealers. Tensile bond strength of adhesive-bonded dentine was significantly reduced when either sealer was cleaned with saline or ethanol. Conversely, air-polishing restored the adhesive strength of the sealer-smeared dentine to the level of the control. Longer and denser resin tags were identified with CLSM when sealers were removed with air-polishing.CONCLUSIONS:Air-polishing with glycine powder was effective in cleaning sealer-smeared dentine, as demonstrated by the rejuvenation of the tensile bond strength of a self-etching adhesive to the decontaminated dentine.CLINICAL SIGNIFICANCE:Glycine powder air-polishing improves the cleanliness of root canal sealer-smeared dentine and rejuvenates adhesive bonding effectiveness.

Enterococcus faecalis is a commensal bacterium commonly found in the human gastrointestinal tract. However, in individuals with compromised immune systems, the pathogen can lead to severe illness. This opportunistic pathogen is associated with secondary apical diseases and is adept at resisting antibiotics and other forms of treatment because of its numerous virulence factors. Enterococcus faecalis is capable of disrupting the normal functions of immune cells, thereby hindering the body's ability to eradicate the infection. However, intensive research is needed in further understanding the adverse immunomodulatory effects of E. faecalis. Potential strategies specific for eradicating E. faecalis have proven beneficial in the treatment of persistent secondary apical periodontitis.

Objectives: To evaluate the capacity of canal wall smear layer removal, precipitation caused by irrigant inter-action, antibacterial activity and cytotoxicity of three 2-in-1 root canal irrigating solutions. Methods: Forty single-rooted teeth were mechanically instrumented and irrigated with QMix, SmearOFF, Irritrol or 0.9% saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Precip-itation after interaction of the irrigating solutions with sodium hypochlorite (NaOCl) was evaluated with 1H nuclear magnetic resonance and mass spectroscopy. Confocal laser scanning microscopy was used to evaluate the antimicrobial activity of the irrigants against Enterococcus faecalis biofilms. Neutral red and clonogenic assays were performed on Chinese hamster V79 cells to evaluate the short-term and long-term cytotoxicity of the irrigants. Results: There was no significant difference between QMix and SmearOFF in eliminating smear layers from the coronal-third and middle-third of the canal spaces. In the apical-third, SmearOFF removed smear layers effec-tively. Irritrol incompletely removed smear layers from all the canal-thirds. When mixed with NaOCl, precipi-tation was evident only with Irritrol. QMix demonstrated a higher E. faecalis cell death percentage and a smaller biovolume. SmearOFF exhibited a larger decrease in biovolume compared with Irritrol, although Irritrol had a higher death percentage. Irritrol was more cytotoxic than the other irrigants on a short-term interval. In terms of long-term cytotoxicity, both Irritrol and QMix were cytotoxic. Conclusion: QMix and SmearOFF performed better in smear layer removal and antimicrobial activity. QMix and Irritrol were cytotoxic when compared to SmearOFF. Irritrol was associated with precipitation after interacting with NaOCl.Clinical significance: Evaluation of the smear layer removal capability, antibacterial activity and cytotoxicity of 2 -in-1 root canal irrigants is necessary to ensure that they are safe to use during root canal treatment.

Objective: To investigate the effectiveness of different cleaning measures on the bonding of resin cement to saliva or blood-contaminated zirconia. Methods: One hundred and forty-one specimens (10 x 10 x 1.5 mm(3)) were fabricated from KATANA (TM) zirconia blocks and contaminated with human saliva or sheep blood. Six cleaning measures were examined: water-rinse, H3PO4, 5.25% NaOCl, ZirClean (TM), Ivoclean and KATANA (TM) Cleaner. Tensile bond strength was evaluated for 13 groups (N=10): six cleaning measures against two contaminations (12 experimental groups) and one uncontaminated control group. Scanning electron microscopy was used to observe the control and water-rinsed specimen surfaces. X-ray photoelectron spectroscopy (XPS) was conducted to identify carbon (C1s), nitrogen (N1s), phosphorous (P2p) and zirconium (Zr3d) peaks, from which the elemental ratios C/Zr, N/Zr and P/Zr were calculated. Results: Although water-rinsing removed most of the contaminants from the zirconia surface, bond strength of resin cement was significantly lower compared with the control. Phosphoric acid was ineffective and NaOCl was less reliable in restoring bond strength. The three commercial cleaners (ZirClean (TM), Ivoclean, KATANA (TM) Cleaner) out-performed the other cleaning measures and restored the bond strength of resin cement to zirconia except for the use of Zirclean (TM) on blood-contaminated surfaces. N/Zr decreased for all cleaned specimens and P/Zr ratio increased for phosphoric acid and KATANA (TM) Cleaner groups. Differences in elemental ratios could indicate different cleaning mechanisms for the zirconia cleaners. Conclusion: All three commercial zirconia cleaners are effective in decontaminating saliva-contaminated or blood-contaminated zirconia and increasing the bond strength of resin cement to contaminated zirconia. Clinical significance: The use of water, phosphoric acid or concentrated sodium hypochorite for cleaning saliva-or blood-contaminated dental zirconia is not recommended. ZirClean (TM) works well on decontamination of saliva contaminated zirconia. Ivoclean or KATANA (TM) Cleaner are useful for decontamination of both saliva-and blood-contaminated zirconia during the intraoral try-in stage to recover the original bond strength of cementation.

OBJECTIVE:To evaluate the efficacy of two sonic-powered irrigation systems, EDDY and EndoActivator, in killing intracanal biofilms. METHODS:Eighty-three instrumented, autoclaved single-rooted human premolars were inoculated with Enterococcus faecalis (ATCC-29212) for 21 days to generate mature, single-species biofilms. The teeth were devided into four groups: irrigation with saline (N = 11); irrigation with 2% NaOCl without agitation (N = 24); irrigation with 2% NaOCl with agitation by the EndoActivaor (N = 24); irrigation with 2% NaOCl with agitation by the EDDY (N = 24). Colony-forming unit (CFU) counts and XTT assay were used to evaluate bacterial load. Additional teeth were split into root-halves for fluorescence staining to examine the percentages of live/dead bacteria in the dentinal tubules present in different canal locations (coronal, mid-root and apical portions). RESULTS:Agitation of 2% NaOCl by EDDY or EndoActivator reduced bacteria load more proficiently than the use of 2%NaOCl without agitation (p < 0.05). No significant difference was detected between the two sonic-powered irrigant agitation systems (p > 0.05). Confocal laser scanning microscopy indicated that both devices had better intratubular bacteria killing efficacy than the use of 2% NaOCl only in all parts of the canal space (p < 0.05), with no significant difference detected between EDDY and EndoActivator (p > 0.05). Elimination of intracanal and intratubular bacteria were less efficient in the apical portion of the canal space for all experimental groups. CONCLUSION:The two sonic-powered irrigant activation systems demonstrated comparable intracanal bacteria reduction efficacy when 2% NaOCl was used for disinfecting E. faecalis biofilms in single-rooted teeth. CLINICAL SIGNIFICANCE:With the use of 2% NaOCl as irrigant, the EDDY and EndoActivator sonic-powered irrigant agitation systems have improved and equivalent intracanal bacteria reduction efficacy but are incapable of completely killing all bacteria that resided within the dentinal tubules of root canals.

OBJECTIVES:An experimental tricalcium silicate and dicalcium silicate-containing endodontic putty has been designed to overcome the issue of reduced shelf life after exposure to atmospheric moisture during repeated opening of the container for clinical retrieval. The present study examined the effects of this experimental hydraulic putty on the mineralogenic characteristics of osteogenic lineage-committed human dental pulp stem cells (hDPSCs), by comparing the cellular responses with a commercially available putty (EndoSequence BC RRM Putty).METHODS:The osteogenic potential of hDPSCs that had been exposed to the putties was examined using quantitative reverse-transcription polymerase chain reaction for osteogenic gene expressions and western blot for osteogenic protein expressions. Alkaline phosphatase activity assay and alizarin red S staining were performed to detect changes in production of the intracellular enzyme and extracellular matrix mineralization respectively.RESULTS:Osteogenic differentiation of the hDPSCs was significantly enhanced after exposure to the pre-mixed hydraulic putties, with no significant difference between these two examined putties.CONCLUSIONS:The experimental hydraulic tricalcium silicate putty enhances osteogenic differentiation of hDPSCs to the same extent as a commercially available tricalcium silicate putty.CLINICAL SIGNIFICANCE:The experimental hydraulic putty appears to be an alternative to the commercial putty when used for applications involving the regeneration of bone in endodontics. Animal models are required for validating its potential in enhancing osteogenesis in vivo.

Objectives: To compare the effectiveness of different sealer cleaning methods on bonding of a self-etch adhesive to root canal sealer-contaminated dentine. Methods: Forty-nine extracted molars were divided into seven groups. Dentine surfaces were exposed and cotaminated with a thin layer of epoxy resin-based sealer (AH Plus (AHP)) or zinc oxide eugenol-based sealer (Pulp Canal Sealer (PCS)). Three cleaning protocols were examined: dry cotton pellet, 70% ethanol-saturated cotton pellet or a surfactant-based cleaner (KatanaTM Cleaner (KC), Kuraray Noritake Dental Inc.). Uncontaminated dentine served as control. The dentine surfaces were bonded with a two-step self-etch adhesive and restored with resin composite. Bond strength testing was performed using a microtensile approach. Two teeth from each group were used for scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The pulpal floor of the teeth was covered with sealer and cleaned. The percentage of zinc/zirconium on the dentine surface was detected to indicate the amount of remnant sealer. Results: Tensile bond strength for uncontaminated dentine control was 46.4 +/- 7.3 MPa; bond strength decreased significantly for the dry cotton group (29.6 +/- 4.2 MPa for AHP, 24.7 +/- 4.7 MPa for PCS, p<0.05). Both ethanol and KC restored bonding performance after cleaning, with no significant difference from the control. Significantly lower MTBS was observed for the ZOE/ethanol subgroup (38.9 +/- 5.1 MPa). Cleaner surfaces and less zinc/zirconium elements were identified by SEM/EDX after cleaning with ethanol or KC. Conclusions: KatanaTM Cleaner decontaminates root canal sealer-smeared dentine surfaces effectively and restores the bonding performance of a self-etch adhesive to dentine. Clinical significance: The surfactant-based KatanaTM Cleaner, originally designed for cleaning zirconia surfaces prior to adhesive bonding, may be used as for cleaning dentine that has been contaminated with unset root canal sealers after root canal treatment to restore the bonding strength of a self-etch adhesive to sealer-contaminated dentine.

Although the effects of tricalcium silicate-based cements (TSCs) on osteogenesis have been extensively investigated, their immunomodulatory role on bone regeneration remains elusive. The present study investigated how TSCs modulate bone regeneration by inducing macrophage polarization. The ex vivo part of the study evaluated the effects of two TSCs on mouse bone marrow-derived macrophages (mBMDMs), and on the osteogenic potential of mouse bone marrow mesenchymal stromal cells (mBMMSCs) that had been co-cultured with TSC-exposed mBMDMs. The in vivo part of the study utilized a rat mandibular defect model to investigate the osteogenic effects of the TSCs on healing of bone defects. Immunofluorescence and immunohistochemistry were used to identify polarization of the macrophages adjacent to bone defects and their cytokine secretion in vivo . The TSCs induced mBMDMs to polarize into the M2 phenotype ex vivo . Osteogenic differentiation of mBMMSCs was enhanced when these cells were co-cultured with mBMDMs that had been exposed to either TSC at non-cytotoxic concentrations. In vivo observations of more profuse new bone formation, presence of defect-adjacent macrophages with M2 phenotype and expression of osteogenesis-related cytokines are indicative of the immunomodulatory role played by TSCs on bone regeneration. This is achieved via induction of macrophage polarization into the M2 phenotype. (c) 2021 Elsevier Ltd. All rights reserved.

OBJECTIVES:The present study evaluated the indentation depth, storage modulus and biocompatibility of an experimental endodontic putty designed for endodontic perforation repair and direct pulp-capping (NeoPutty). The results were compared with the properties associated with the commercially available EndoSequence BC RRM Putty (ES Putty). METHODS:Indentation depth was measured by a profilometer following indentation with the 1/4 lb Gilmore needle. Elastic modulus was evaluated using a strain-controlled rheometer. The effects of eluents derived from these two putties were examined on the viability and proliferation of human dental pulp stem cells (hDPSCs) and human periodontal ligament fibroblasts (hPDLFs), before (1 st testing cycle) and after complete setting (2nd testing cycle). RESULTS:The ES Putty became more difficult to ident and acquired a larger storage modulus after exposure to atmospheric moisture. Biocompatibility results indicated that both putties were relatively more cytotoxic than the bioinert Teflon negative control, but much less cytotoxic than the zinc oxide-eugenol cement negative control. NeoPutty was less cytotoxic than ES putty in the 1st testing cycle, particularly with hDPSCs. Both putties exhibited more favourable cytotoxicity profiles after complete setting. CONCLUSIONS:NeoPutty has a better window of maneuverability after exposure to atmospheric moisture. From an in vitro cytotoxicity perspective, the NeoPutty may be considered more biocompatible than ES putty. CLINICAL SIGNIFICANCE:The experimental NeoPutty is biocompatible and is capable of reducing the frustration of shortened shelf life when jar-stored endodontic putties are exposed to atmospheric moisture during repeated opening of the lid for clinical retrieval.