Search Results (51)

Background and Objectives: Dental adhesives augmented with magnetic nanoparticles (MNPs) have been proposed to prevent microleakages. MNPs dispersed in a dental adhesive reduce the thickness of the adhesive layer applied in a magnetic field and enhance the bond strength by favoring the penetration of the adhesive into dentinal tubules. However, the restoration’s color has been found to be affected by the MNPs. This study tests the hypothesis that MNP coating can alleviate the esthetic impact of magnetic dental adhesives. Materials and Methods: We synthesized Fe₃O₄ MNPs with silica coating (MNPs-SiO₂), calcium-based coating (MNPs-Ca), and no coating. Their morphology was studied using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Their chemical composition was assessed by energy-dispersive X-ray spectroscopy (EDX), and magnetic properties were measured using a vibrating sample magnetometer. FTIR spectroscopy was used to evaluate the polymerization of the MNP-laden adhesive. We prepared cavities in molar phantoms divided in four groups (n = 15 each) restored using the same adhesive with different MNP contents: Group 0 (G0)—no MNPs, G1—MNPs-SiO₂, G2—MNPs-Ca, and G3—uncoated MNPs. The restoration’s color was quantified in the CIELAB color space using a dental spectrophotometer. Results: MNPs-SiO₂ were globular, whereas MNPs-Ca had a cubic morphology. The SiO₂ layer was 73.1 nm ± 9.9 nm thick; the Ca(OH)₂ layer was 19.97 nm ± 2.27 nm thick. The saturation magnetization was 18.6 emu/g for MNPs-SiO₂, 1.0 emu/g for MNPs-Ca, and 65.7 emu/g for uncoated MNPs. MNPs had a marginal effect on the adhesive’s photopolymerization. The mean color difference between G0 and G2 was close to the 50:50% acceptability threshold, whereas the other groups were far apart from G0. The mean whiteness index of G2 did not differ significantly from that of G0; G1 deviated marginally from G0, whereas G3 differed significantly from G0. Conclusions: These results suggest that MNP coating can mitigate the influence of MNP-laden dental adhesives on the color of restorations. Full article

Enterococcus faecalis (E. faecalis) is a major pathogen responsible for refractory apical periodontitis (RAP). It can penetrate deep into dentinal tubules, form persistent biofilms, and exhibit antibiotic resistance, thereby limiting the efficacy of conventional antimicrobial treatments. Bacteriophages (phages), due to their strong lytic activity and host specificity, have emerged as promising alternatives. In this study, a novel strictly lytic phage, ZXL-01, was isolated from lake water in Jilin, China. ZXL-01 demonstrated remarkable stability under extreme conditions, including thermal tolerance at 60 °C for 1 h and a wide pH range (4–11). Whole-genome sequencing (GenBank accession number: ON113334) revealed a genome of 40,804 bp with no virulence or tRNA genes, confirming its identity as an E. faecalis phage. Importantly, ZXL-01 exhibited potent antibiofilm activity, reducing biofilm biomass by approximately 69.4% in the inhibition group and 68.4% in the lysis group (both p < 0.001). In an in vitro root canal infection model induced by E. faecalis, scanning electron microscope (SEM) observations confirmed that ZXL-01 effectively inhibited biofilm formation and disrupted mature biofilms. These findings highlight the potential of ZXL-01 as a novel antimicrobial agent for the treatment of E. faecalis-associated apical periodontitis. Full article

Endodontic infections are characterized by complex polymicrobial communities residing within the intricate root canal system. Traditional chemomechanical methods frequently fail to achieve complete microbial eradication, especially in cases involving biofilm-forming and resistant species. This systematic review synthesizes current evidence on the molecular basis and antimicrobial efficacy of the neodymium-doped yttrium aluminum garnet (Nd:YAG) laser in root canal disinfection, particularly against polymicrobial infections. A comprehensive literature search was conducted in the PubMed, Embase, Scopus, and Cochrane databases in accordance with PRISMA 2020 guidelines. Experimental and preclinical studies evaluating the bactericidal properties of Nd:YAG laser therapy were included. The Nd:YAG laser demonstrated significant reductions in total microbial load through photothermal effects, including denaturation of proteins, disruption of cell membranes, and degradation of mixed-species biofilms. Although complete sterilization was not consistently achieved, its ability to penetrate dentinal tubules and target microbial consortia offers substantial adjunctive value. Standardization of laser parameters and further clinical studies are needed to validate these findings and establish Nd:YAG laser use in routine endodontic disinfection protocols. Full article

Clinical root canal therapy which takes place through mechanical and chemical strategies is faced with challenges in eliminating bacteria owing to the intricate and curved nature of the root canal system. Moreover, the plaque biofilm within the root canal hinders drug penetration and limits treatment efficacy. Hence, efficient root canal therapy hinges on penetrating into the root canal and overcoming the barriers presented by the plaque biofilms. To penetrate and eradicate biofilms effectively at the root canal, we designed a novel magnetic nanoparticle (MN)-based nanoplatform which was synthesized by the self-polymerization of dopamine on the surface of Fe₃O₄ MNs, and then loaded minocycline through the electrostatic interaction. The therapeutic efficacy of minocycline-loaded magnetic nanoparticles (FDM MNs) under a magnetostatic field was observed by various antibacterial experiments. The synthesized FDM MNs exhibited favorable biocompatibility and robust anti-biofilm efficacy. The designed nanoparticles could effectively navigate biofilms to eradicate bacteria residing deep with the assistance of magnetic force. Furthermore, FDM MNs penetrated into dentin tubules under a magnetic field, effectively disrupting biofilms for deep sterilization. The significant results offered valuable experimental evidence to support the potential clinical utility of magnetic nanoparticles for managing pulpitis and periapical inflammation. Full article

The impact of adding silver nanoparticles (AgNPs) to bioceramic (BC) sealer on their ability to penetrate dentinal tubules is still unknown. Thus, this confocal laser scanning microscopic (CLSM) study aimed to assess the extent of dentinal tubule penetration of BC sealer (TotalFill^® Hiflow BC Sealer™, FKG, Switzerland) with and without AgNPs using the single-cone (SC) technique and the continuous-wave condensation (CWC) technique. AgNPs alone as well as in a mixture with the BC sealer were characterized using scanning electron microscopy and transmission electron microscopy. Single-rooted extracted human teeth (N = 100) were selected and prepared, and then divided into four groups (n = 25). Group 1 (BC/SC): BC sealer obturated with the SC technique. Group 2 (BC+AgNPs/SC): BC sealer with AgNPs obturated with the SC technique. Group 3 (BC/CWC): BC Sealer obturated with the CWC technique. Group 4 (BC+AgNPs/CWC): BC Sealer with AgNPs obturated with the CWC technique. After 2 weeks, roots were horizontally sectioned to obtain 1 mm thick dentin slices that were evaluated with CLSM. Sealer dentinal tubule penetration area and the maximum depth of penetration were measured. Data were analyzed with one-way ANOVA and the Tukey multiple comparison tests (p ≤ 0.05). The characterization process demonstrated a spherical-shaped nanoparticles without obvious agglomeration. The results showed that Group 2 (BC+AgNPs/SC) significantly demonstrated the highest mean tubular penetration depth, while group 3 (BC/CWC) had the lowest mean depth. Group 2 (BC+AgNPs/SC) exhibited the significantly highest mean value for the total area of penetration. However, groups 1 (BC/SC) and 3 (BC/CWC) exhibited the lowest mean value of total penetration area, with no statistically significant difference. The integration of AgNPs with BC sealer markedly enhanced penetration into dentinal tubules. The SC technique demonstrated superior penetration relative to the CWC technique. Full article

Background: Adhesion within endodontic obturation material and root canal walls improves the efficacy of the endodontic treatment by establishing a barrier that inhibits reinfection and entombs residual bacteria. This study evaluates the push-out bond strength (POBS) of calcium silicate sealers compared to an epoxy-resin-based sealer. Methods: A total of 36 extracted mono-radicular teeth were prepared with Pro Taper Ultimate and irrigated with 5.25% sodium hypochlorite and 17% EDTA. The specimens were randomly split into three groups (n = 12) according to the endodontic sealer and filling technique used as follows: Ah Plus with the continuous wave condensation technique (CWC), Ah Bioceramic (Ah Bio) with the single-cone technique, and Total Fill Hi-Flow (FKG Hi-Flow) with the CWC technique. The material was allowed to set for 4 weeks, and afterwards, the roots were placed in acrylic resin and sectioned into 1 mm transverse slices. A POBS test was conducted using a universal testing machine, and the mode of bond failure was assessed at 4× magnification using a stereomicroscope. Six specimens from each group were selected for SEM-EDX examination to evaluate dentinal tubule penetration. The data were analysed using analysis of variance and Tukey and Bonferroni post hoc tests. Results: The POBS tests revealed higher values for Ah Plus in comparison to both calcium silicate sealers (p < 0.001), while FKG Hi-Flow showed superior results to Ah Bio (p < 0.001). The cohesive mode of failure was prevalent in all three groups. Conclusions: In conclusion, the resin-based sealer showed higher bond strength and better dentinal tubule penetration than the two calcium silicate sealers tested, while FKG Hi-Flow outperformed AH Bio. Full article

Background: Lasers from the erbium family have been investigated to activate irrigation with sodium hypochlorite (NaOCl), improving the disinfection depth of the dentinal tubules of the root canal walls during root canal treatment. However, the possibility of laser-activated irrigation (LAI) in retro-cavity preparation has not been investigated to the date. The aim of our experimental study is to evaluate the efficacy of NaOCl gel penetration inside the dentinal tubules when activated during retro-cavity preparation, comparing passive ultrasonic activation (PUI) and Er,Cr:YSGG LAI. Materials and Methods: Fifty extracted mature single-root human teeth were divided into four groups (control, PUI, and two LAI groups with different NaOCl concentrations). After conventional endodontic treatment and root end resection, NaOCl gel (impregnated with rhodamine dye for confocal laser scanning microscopy (CLSM) analysis) was applied and activated according to the study group. The penetration index and mean penetration length were measured using computer software. Results: Both penetration index and mean penetration length were found to have increased in the PUI group compared to the control samples. However, LAI had a better penetration that was statistically significant compared to both the PUI and control groups. The difference in NaOCl concentration in the laser groups did not affect the penetration values. Conclusions: Within the limitations of our in vitro study using NaOCl gel activation in the retro-cavity after apicectomy, Er,Cr:YSGG LAI significantly enhanced NaOCl gel penetration capacity compared to PUI, regardless of its concentration. LAI can enhance its penetration in a safe way, avoiding its extrusion to the surrounding periapical tissues. Full article

This study aimed to evaluate the fracture resistance of root and sealer penetration after obturation using an epoxy resin sealer AH plus (AH+) and two different bioactive endodontic sealers, i.e., Totalfill BC Hiflow (TF BC), and experimental injectable bioactive glass (Exp.BG). A thermo-sensitive injectable sealer was prepared by using a non-ionic triblock copolymer and bioactive glass. The root canals of human extracted teeth were obturated with the respective sealers. The fracture resistance was analyzed at different time intervals, i.e., days 7, 30, and 90. The morphological and elemental analyses of the fractured roots were conducted with a scanning electron microscopy and a electron dispersive spectroscopy. Sealer penetration depth and the percentage of penetrated sealers into the dentinal tubules were assessed with the confocal laser scanning microscope. Statistical analysis was performed using a one-way ANOVA post hoc Tukey’s test. The mean fracture force in AH+ was significantly higher on day 30 (664.08 ± 138.8 N) compared to day 7 (476.07 ± 173.2 N) and day 90 (493.38 ± 120.18 N). There was no statistically significant difference between the TF BC and Exp.BG at different time intervals. The maximum penetration was observed in the middle region compared to coronal and apical for the Exp.BG, followed by the TF BC and AH+ groups; however, a nonsignificant difference in penetration was found over time. It is concluded that the TF BC group showed overall better fracture resistance than AH+ at day 90. Exp.BG showed comparable sealer penetration to those of TF BC and better than those of AH+. Full article

Endodontic infections arise from the interactive activities of microbial communities colonizing in the intricate root canal system. The present study aims to update the latest knowledge of nanomaterials, their antimicrobial mechanisms, and their applications in endodontics. A detailed literature review of the current knowledge of nanomaterials used in endodontic applications was performed using the PubMed database. Antimicrobial nanomaterials with a small size, large specific surface area, and high chemical activity are introduced to act as irrigants, photosensitizer delivery systems, and medicaments, or to modify sealers. The application of nanomaterials in the endodontic field could enhance antimicrobial efficiency, increase dentin tubule penetration, and improve treatment outcomes. This study supports the potential of nanomaterials as a promising strategy in treating endodontic infections. Full article

This study aimed to assess the penetration of AH-Plus (AHP) and AH-Plus Bioceramic (AHPB) sealers into dentinal tubules subsequent to different irrigation activation protocols. One hundred fifty teeth were divided into five groups according to the final irrigation protocol: conventional syringe irrigation (CSI), EndoActivator (EA), passive ultrasonic irrigation (PUI), Er,Cr:YSGG laser, and SWEEPS. Then, the teeth were divided into two subgroups (n = 15) according to the canal sealer type. The maximum penetration depth (MPD) point and percentage of the sealer were evaluated using confocal laser scanning microscopy. Then, the data were statistically analyzed. The highest MPD values were observed in the SWEEPS groups, while the lowest value was in the CSI groups. Considering the effect of the sealer type and irrigation protocol interaction, there was a significant difference between the Er,Cr:YSGG laser, and EA groups for the AHPB sealer (p < 0.05), while it was insignificant for the AHP sealer (p > 0.05). The AHP and AHPB sealers statistically presented similar penetration properties. Laser-activated irrigation presented a higher sealer penetration compared to the other techniques. Full article

Adequate root canal sealing is essential for the success of endodontic treatment. There are numerous techniques available; identifying simple and efficient techniques is important to provide good patient care. The purpose of the study was to compare the maximum penetration depth and the percentage of sealant penetration of an endodontic sealer into dentine tubules using cold lateral condensation, continuous wave, and hybrid techniques, and to contrast the effectiveness of two different tapered gutta-percha master cones (0.02 and 0.04). A sample of sixty single root teeth was used. Six experimental groups were formed from the three filling techniques and the two tapered master cones. Images were acquired using a confocal laser scanning microscope. In the apical root third, the penetration percentage was higher in the hybrid compared with the continuous wave technique. The results indicated a higher penetration depth of hybrid compared with cold lateral condensation in the middle and coronal thirds, and in the apical third, a higher penetration was identified in the hybrid group compared with the continuous wave group. No significant differences in penetration were found comparing 0.02 with 0.04 taper gutta-percha groups. The coronal cross-sections presented a higher penetration than the apical third sections. In conclusion, the hybrid technique a had higher maximum sealer penetration than the continuous wave in the apical third, and the coronal third hybrid and continuous wave had a higher penetration than cold lateral condensation. Full article

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. Full article

A void-free obturation during root canal treatment on primary teeth is currently very difficult to attain. In this study, the pulpectomy filling abilities of Bio-C Pulpecto (Angelus, Basil, Londrina, Paraná, Brazil) and of zinc oxide eugenol, or “ZOE” (DenPro, Prevest, New York, NY, USA), were compared using several in vitro techniques. Therefore, 30 primary anterior teeth were used in the present in vitro study. Analysis of variance (ANOVA), including a multiple comparison procedure (Holm-Sidak method, Dunn’s Method, or Tukey test), was used. On micro-CT, Bio-C Pulpecto exhibited higher void percentages than did ZOE (10.3 ± 3.8%, and 3.5 ± 1.3%), respectively (p < 0.05). With digital microscopy, higher total void percentages were found in the BC (13.2 ± 26.7%) group compared to the ZOE (2.7 ± 2.8%) group (p < 0.05). With the CLSM, mean tubular penetration depths were higher for Bio-C Pulpecto than for ZOE in all canal thirds (p < 0.05). SEM images demonstrated no tags into dentinal tubules in either group throughout the three thirds. Moreover, higher statistically significant flowability was found for Bio-C (2.657 ± 0.06 mm) compared to ZOE (1.8 ± 0.13 mm) (p < 0.05). The findings of this study indicate that neither ZOE nor Bio-C Pulpecto appears to meet the criteria for an ideal root canal filling paste for primary teeth. This study laid the groundwork for future research by determining how micro-CT, digital microscopy, SEM, and CLSM contribute to our understanding of the filling process of primary teeth. More thorough research on the mechanism of root canal obturation on primary teeth is required to achieve a long-term successful root canal therapy in young children. Full article

Background: The proper sealing of the root canal seems to be critical to obtain a stable result of endodontic therapy. The sealer’s penetration into dentinal tubules during root canal treatment is probably a crucial factor to provide better clinical results. The aim of this study was to compare the effect of three irrigation protocols on the penetration of the epoxy sealer into dentinal tubules and two dyes used to stain the sealer. Methods: Ninety single-canaled human teeth with straight roots were used. The root canals were instrumented with Reciproc instruments up to the size 40/04 ISO. The teeth were divided into three groups (n = 30). The root canals of each group were rinsed accordingly: the control group 1: 5.25% sodium hypochlorite (NaOCl); the experimental group 2: smear layer removal (two times alternatively: 40% citric acid and 5.25% NaOCl) and NaOCl; the experimental group 3: smear layer removal (same as in group 2) and isopropyl alcohol. In each group the roots were further divided into 2 subgroups (n = 15). The root canals were obturated using warm vertical compaction technique of gutta-percha with AH Plus sealer marked with hydrophilic fluorescein (subgroup F) or hydrophobic porphyrin (subgroup P). After 72 h, one-millimeter-thick cross-sections were cut in two, five and eight millimeters distance from the apex. The depth of the penetration of the sealer into the dentinal tubules (resin tags) was measured with the use of a confocal laser microscope. Results: In of all the root parts, the longest resin tags were observed in group 2, whereas the shortest ones were found in group 1 (in the porphyrin subgroups all differences were statistically significant). Within the fluorescein subgroups, the differences between all groups were statistically significant in the middle section of the roots. In the apical and the coronal sections, significant differences were observed between group 1 and the other two groups. Conclusions: The isopropyl alcohol at the end of the irrigating protocol did not affect the higher sealer penetration of the sealer into the dentinal tubules compared with sodium hypochlorite. With the limitation of this study, the hydrophobic porphyrin may be considered as the favorable dye choice to stain endodontic sealers in further studies with confocal laser scanning microscopy, but the methods and reagents used should still be in the research phase. Full article

Background: Once the chemo-mechanical preparation of root canals is finished, achieving a complete seal of the root canal system becomes crucial in determining the long-term success of endodontic treatment. The important goals of root canal obturation are to minimize leakage and achieve an adequate seal. Thus, a material that possesses satisfactory mechanical characteristics, is biocompatible, and has the ability to penetrate the dentine tubules adequately is needed. Aim: This study aimed to compare the penetrability and bond strength between two calcium silicate-based sealers and an epoxy resin-based sealer, as well as examine the relationship between penetrability and bond strength for the different sealers. Method and materials: Thirty-nine recently extracted single-rooted human premolar teeth were instrumented and divided evenly into three groups (n = 13), according to the sealer used for obturation: AH Plus Jet, EndoSequence, and AH Plus Bioceramic Sealer. Three teeth (30 slices) were randomly selected out of each for analysis using confocal laser scanning microscopy to assess penetrability. The remaining ten teeth (90 slices) in each group were subject to push-out tests using a universal testing machine. All teeth were sectioned into nine transverse slices of 0.9 mm thickness for their respective tests (apical, middle, coronal). Results: AH Plus Jet exhibited significantly lower penetrability and significantly higher bond strength compared to EndoSequence BC sealer (p = 0.002) and AH Plus Bioceramic Sealer (p = 0.006). There was no significant difference between EndoSequence BC sealer and AH Plus Bioceramic Sealer in terms of either penetrability or bond strength. No correlation was found between penetrability and bond strength. Conclusions: Within the limitation of this study and regardless of the location in the canal, the bioceramic based root canal sealers appeared to perform better than the epoxy resin-based sealer in terms of dentinal penetration rate. Further studies are required to compare other biomechanical properties of bioceramic sealers including setting characteristics and bacterial leakage. Full article