Evaluating antimicrobial activity and cytotoxicity of silver nanoparticles incorporated into reinforced zinc oxide eugenol: an in vitro study.

PURPOSE: This study aimed to evaluate the antibacterial and cytotoxic effects of reinforced zinc oxide-eugenol (rZOE) incorporated with different concentrations of silver nanoparticles (AgNPs). METHODS: The pastes of rZOE alone or mixed with AgNPs at concentrations of 1%, 2%, and 5% of weight were prepared. In vitro antimicrobial activity of prepared materials against Streptococcus (S.) mutans and Lactobacillus (L.) acidophilus were evaluated after 2, 4, and 6 h of contact times using direct contact test (DCT) and also following 24 h incubation by well-diffusion test (WDT). The cytotoxicity of the tested materials on human dental pulp stem cells was also determined by MTT assay. RESULTS: The DCT demonstrated that the time-dependent reductions of the colony numbers of both bacteria by three different concentrations of AgNPs incorporated into rZOE were equal but steeper than the rZOE alone (P < 0.05). The increases in growth inhibition zones of S. mutans and L. acidophilus were associated with the increasing concentration of AgNPs mixed with rZOE in the WDT; however, statistical analysis did not show any significant differences (P = 0.092). The MTT assay revealed a significantly lower percentage of cell viability after 1 day of culture only with the rZOE + AgNP5% in comparison to the rZOE alone (P = 0.011) and the control medium (P = 0.001). CONCLUSION: Since the antimicrobial activities of three different concentrations of AgNPs incorporated into rZOE were equal and AgNPs had lower toxicity at lower concentrations, using AgNPs at 1% concentration is suggested to be mixed with rZOE.

Zinc oxide-ozonated olive oil as a new root canal filling material in primary molars: a clinical randomized controlled trial.

OBJECTIVES: The complex root canal anatomy of primary teeth keeps it very tricky to attain appropriate cleansing by biomechanical instrumentation, so obtaining an obturating material with excellent antimicrobial properties is a challenge in current clinical pulpectomy practice. So, this study aimed to assess the clinical and radiographic performance of zinc oxide-ozonated olive oil as a primary root canal filling material. MATERIALS AND METHODS: Ninety non-vital primary molars in children ranging from 4 to 8 years were allocated into three groups in which root canals were filled with zinc oxide-ozonated olive oil, zinc oxide-olive oil, and zinc oxide-eugenol (ZOE) according to each group after pulpectomy procedure. Clinical and radiographic evaluations were done at 3-, 6-, and 12-month follow-up periods. Statistical analysis was performed for the collected data. RESULTS: All study groups showed a significant improvement regarding clinical signs and symptoms during follow-up periods. Ozonated-olive oil group revealed a significant increase in furcation radiodensity and a decrease in periodontal ligament space at 3-, 6-, and 12-month follow-up intervals compared to other groups. CONCLUSION: Zinc oxide-ozonated olive oil and zinc oxide-olive oil paste had shown good clinical and radiographic success for primary teeth pulpectomy. CLINICAL RELEVANCE: The intricate torturous primary root canal anatomy, in addition to the child's negative behavior, interferes with the complete debridement, so the long-lasting antibacterial effect of the primary root canal filling material aids in the pulpectomy success.

Antibiofilm and antimicrobial activity of temporary filling materials on root canals: an in situ acid challenge.

The present study evaluated the antibiofilm and antimicrobial effects of temporary restorative materials on root canals after an intra-oral challenge. Seventy roots were endodontically treated and divided into 5 groups: high-viscosity glass ionomer (HV-GIC), light-activated glass ionomer (RM-GIC), zinc-oxide cement without eugenol (ZO), zinc-oxide cement with eugenol (ZOE), and unsealed roots (negative control). For 28 days, 14 participants used intra-oral devices with five roots, and drops of sucrose were applied onto them. The amount of biofilm and the bacterial counts were analyzed by Kruskal-Wallis and Dunn, and by two-way ANOVA and Tukey (α = 0.05). HV-GIC and RM-GIC better inhibit biofilm, followed by ZO and ZOE. Unsealed roots had the largest biofilm accumulation (p = 0.002) and higher bacterial penetration than restored roots (p = 0.023). A low amount of Streptococcus was found in RM-GIC and ZOE-restored roots without difference from HV-GIC (p = 0.021). The low amount of Enterococcus (p = 0.003) was found in the ZOE-restored roots, without difference from GICs.

Ferric sulfate pulpotomy in primary teeth with different base materials: a 2-year randomized controlled trial.

OBJECTIVE: To evaluate the effects of zinc oxide-eugenol, calcium hydroxide, and mineral trioxide aggregate as base materials on the clinical and radiographic success of ferric sulfate pulpotomies in primary molars. METHOD AND MATERIALS: Following hemostasis with 15.5% ferric sulfate, 105 teeth were randomly allocated to three groups: Group 1, zinc oxide-eugenol; Group 2, calcium hydroxide; and Group 3, mineral trioxide aggregate. All teeth were restored with stainless-steel crowns. Clinical and radiographic examinations were conducted at 6, 12, 18, and 24 months. RESULTS: After 24 months, clinical success rates for Groups 1 to 3 were 97.1% (34/35 teeth), 94.2% (33/35 teeth), and 97.1% (34/35 teeth), respectively (P > .05). Radiographic success rates were 65.7% (23/35 teeth), 65.7% (23/35 teeth), and 77.1% (27/35 teeth), respectively (P > .05). Internal resorption was the most observed radiographic finding (15/105 teeth). CONCLUSIONS: The choice of zinc oxide-eugenol, calcium hydroxide, and mineral trioxide aggregate, as base materials, did not affect the clinical and radiographic success of ferric sulfate pulpotomies in primary teeth.

Cytocompatibility of filling pastes by primary teeth root simulating model.

Evaluate the cytocompatibility of Calen®/ZO, Calcicur®, Vitapex®, Endoflas®, and zinc oxide/eugenol-based (ZOE) root canal pastes (RCP) to human primary osteoblasts (HPO) through a simplified model for primary teeth. The model employed pipette tips filled with 0.037 g of paste, exposed to 185 µL of culture medium for 24 h (n = 6). Release of components was analysed by Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR). HPO were exposed to conditioned media for 24 h. Cell viability was assessed by cell density and metabolic activity, and release of interleukin 6 (IL-6), vascular endothelial growth factor (VEGF) and fibroblast growth factor (bFGF) by immunological assay. Physicochemical properties and antimicrobial efficacy were also evaluated. 1H-NMR spectra analysis showed similarity between ZOE, Endoflas®, Calcicur®, and Vitapex® compared to Calen®/ZO and positive control, which showed distinct released components. Calen®/ZO and Calcicur® exhibited high alkaline pH in all periods and showed similar solubility. Calen®/ZO, ZOE, and Vitapex® showed similar flow rate. Calen®/ZO, Calcicur®, and Vitapex® did not exhibit antimicrobial efficacy. Calen®/ZO presented cytotoxicity (p < 0.05). Pastes did not increase IL-6 release compared to control. Apart from Vitapex®, all pastes significantly induced VEGF/bFGF release. Interactive effects among released products may affect biological response to filling pastes. Calcicur®, ZOE, Endoflas® and Calen®/ZO presented good to moderate cytocompatibility, with low impact on pro-inflammatory cytokine release and induction of growth factors of interest to tissue repair. This simplified model, specific for the evaluation of the cytocompatibility of RCPs on primary teeth, suggests how these pastes might contribute to bone repair in clinical situations of apical periodontitis in children.

Design, Evaluation And Antimicrobial Activity Of Egyptian Propolis-Loaded Nanoparticles: Intrinsic Role As A Novel And Naturally Based Root Canal Nanosealer.

BACKGROUND: Propolis is a unique natural adhesive product collected by honeybees. It contains a diversity of bioactive compounds with reported functional properties such as antioxidants, antibacterial, antifungal, anti-inflammatory, antiviral and anticancer activity. Dental caries is a worldwide problem that caused by microbial growth usually progress from tooth enamel to the underlying pulpal tissues and root canal. This situation could be controlled by a sequence of steps to remove microorganisms and fill root canal with a suitable long-lasting root canal sealer. Unfortunately, leachable and degradation products of the currently used sealers compromised their antimicrobial activity by inflammatory modulation associated with irritation and toxicity of periapical tissues. MATERIALS AND METHODS: Hence, propolis was selected to be designed as a natural root canal sealer due to its amazing functional properties. Moreover, its handling properties were enhanced and potentiated by its incorporation in polymeric nanoparticles (NPs). Frist, propolis was collected, extracted and analyzed for its bioactive compounds. After that, propolis-loaded NPs of PLGA (ProE-loaded NPs) were developed and fully characterized regarding physicochemical properties, in vitro release and in vitro cytotoxicity. Then, root canal sealers were fabricated and assayed for their antimicrobial activity. Both cytotoxicity and antimicrobial activity were compared to those of a model sealer; AH Plus®. RESULTS: The results revealed that spherical nanoscopic NPs with narrow size distribution were obtained. ProE-loaded NPs exhibited accepted entrapment efficiency (>80) and prolonged release. In vitro cytotoxicity study confirmed the safety of ProE-loaded NPs. Also, the developed sealers showed antimicrobial activity versus bacterial strains of Enterococcus faecalis and Streptococcus mutans and antifungal activity against Candida albicans. CONCLUSION: ProE-loaded NPs could be incorporated in and represented as a root canal sealer with prolonged release and enhanced cytocompatibility as well as antimicrobial activities.

A novel antibacterial resin-based root canal sealer modified by Dimethylaminododecyl Methacrylate.

Persistent apical periodontitis, mainly caused by microorganisms infections, represents a critical challenge for endodontists. Dimethylaminododecyl methacrylate (DMADDM) is a well-studied and potent antibacterial agent used in various studies described in the literature. The aim of this study is to develop a novel antibacterial root canal sealer by incorporating DMADDM into EndoREZ and investigate the properties of the resulting material. Different mass fractions (0, 1.25%, 2.5%, and 5%) of DMADDM were incorporated into EndoREZ and the cytotoxicity, apical sealing ability and solubility of the resulting material were evaluated. Furthermore, a direct contact test, determination of colony-forming units, a crystal violet assay, scanning electronic microscopy and live/dead bacteria staining were performed to evaluate the antibacterial effect of the sealer to multispecies bacteria (Enterococcus faecalis, Streptococcus gordonii, Actinomyces naeslundii, and Lactobacillus acidophilus), in planktonic cells or biofilms. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction were carried out to assess the composition of the multispecies biofilms. No difference on the cytotoxicity, apical sealing ability and solubility between sealers containing DMADDM (1.25%, 2.5%) and EndoREZ (0%) could be determined. However, when the mass fraction of DMADDM increased to 5%, significantly different properties were found compared to the 0% (p < 0.05) group. Moreover, incorporating DMADDM into the sealer could greatly improve the antibacterial properties of EndoREZ. In addition, the composition ratio of E. faecalis could be decreased in multispecies microecology in sealers containing DMADDM. Therefore, a EndoREZ sealer material containing DMADDM could be considered useful in clinical applications for preventing and treating persistent apical periodontitis.

Influence of plant extracts mixed with endodontic sealers on the growth of oral pathogens in root canal: An in vitro study.

INTRODUCTION: Microbes are considered as the primary etiological agents in endodontic diseases. Ways of reducing these agents are root canal debridement and antibacterial filling materials. One of the factors in determining the success of endodontic treatment previously was sealing root canals with materials possessing potent bactericidal effect. Due to cytotoxic reactions of sealers and their inability to eliminate bacteria completely from dentinal tubules, trend to use natural plants extracts have been introduced. AIM: To compare antimicrobial activity of endodontic sealers added to herbal extracts. MATERIALS AND METHOD: Three sealers mixed with three herbal extracts were evaluated against seven strains of bacteria at various time intervals using Agar Diffusion Test. The mean zones of inhibition were measured. STATISTICAL ANALYSIS: All statistical analysis was performed using the SPSS 15 statistical software version, Chicago. Intergroup comparison was evaluated using Kruskal Walls test along with Mann Whitney U test. The Intragroup comparison was evaluatd using Friedman test along with Wilcoxon test. RESULTS: Statistically significant zones of bacterial growth inhibition were observed largest with Zinc Oxide Eugenol based sealer when mixed with Glycyrrhiza glabra (Licorice) followed in descending order by zinc oxide eugenol based sealer mixed with Tinospora cordifolia (Guduchi) and Mimusops elengi (Bakul) respectively. CONCLUSION: Zinc Oxide Eugenol based sealer with herbal extracts produced largest inhibitory zones followed in descending order by Resin based sealer and Calcium hydroxide along with three herbal extracts respectively.

Evaluation of the biocompatibility of root canal sealers on human periodontal ligament cells ex vivo.

The aim of this study was to evaluate the biocompatibility of two comparatively new calcium silicate containing sealers (MTA-Fillapex and BioRoot-RCS) with that of two established sealers (AH-Plus, epoxy resin-based; Pulp-Canal-Sealer, zinc oxide eugenol containing). Human periodontal ligament cells (PDL-cells) were brought in contact with eluates from freshly mixed and set sealer. The sealers were mixed strictly according to the manufacturers' instructions and identically samples were produced. 1:1, 1:2, and 1:10 dilutions of sealers extract were used. Extracts from freshly mixed sealer were added to the PDL-cells on day one to simulate a clinical scenario. Subsequently, at 24 h, 7, 14, and 21 days extracts form set sealers were used for PDL-cell culturing. PDL-cell viability was analyzed by living-cell-count, MTT-assay, and living/dead-staining, cytotoxicity by LDH-assay, and changes by Richardson-staining. All data were statistically evaluated by one way ANOVA and a posthoc analysis with Bonferroni-Holm testing (p < 0.05). In contact with BioRoot-RCS a regeneration of the PDL-cells were observed over time. This sealer showed the lowest toxicity in a freshly mixed and set state (p < 0.05). MTA-Fillapex and Pulp-Canal-Sealer were cytotoxic in a fresh as well as in a set state, whereas AH-Plus was cytotoxic in a freshly mixed state, but not when the sealer was set. BioRoot-RCS is biocompatible and bioactive because it seems to have a positive influence on the PDL-cell metabolism. Pulp Canal Sealer and MTA-Fillapex showed no biocompatibility in contact with PDL-cells at all. Freshly mixed AH Plus is less biocompatible on PDL than in a set state.

Comparative Biocompatibility and Osteogenic Potential of Two Bioceramic Sealers.

INTRODUCTION: Endodontic sealers have traditionally been used to seal dentinal tubules, creating a homogenous interface between the obturation material and the dentinal walls. However, bioceramic sealers have potential added benefits because of their bioactivity. After adequate endodontic therapy, osseous healing is largely dependent on the differentiation and activity of osteoblasts. We hypothesized that EndoSequence BC Sealer (Brasseler, Savannah, GA) and ProRoot ES (Dentsply Tulsa Dental Specialties, Johnson City, TN) have superior biocompatibility and osteogenic potential compared with Roth (Roth International, Chicago, IL) and AH Plus (Dentsply DeTrey Gmbh, Konstanz, Germany) sealers. METHODS: A murine osteoblast precursor cell line (IDG-SW3) was exposed to a wide range of concentrations for each of the sealers for 7 days. The relative cell viability was determined by luminescence assay based on adenosine triphosphate quantification (CellTiter-Glo [Promega, Madison, Wisconsin]). The osteogenic potential was determined by fluorescence microscopy of DMP-1 expression, alizarin red staining, and real-time reverse transcription polymerase chain reaction with primers specific for known markers of osteogenesis such as DMP-1, ALP, and Phex. Data were analyzed with 2-way analysis of variance or 1-way analysis of variance with the Bonferroni post hoc test. RESULTS: Both bioceramic sealers have excellent biocompatibility even at high concentrations. Conversely, cell death was detected when Roth and AH Plus were used at concentrations 100× lower than the bioceramic groups. Importantly, both bioceramic sealers significantly enhanced osteoblastic differentiation although greater responses were noted with EndoSequence BC Sealer. This was evidenced by increased DMP-1 expression, robust up-regulation of osteogenic marker gene expression, and superior mineral deposition. Osteoblastic differentiation and function were significantly impaired when Roth or AH Plus sealer was used. CONCLUSIONS: EndoSequence BC Sealer and ProRoot ES were significantly more biocompatible and promoted osteoblastic differentiation, a bioactivity not found in AH Plus and Roth sealers.

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials.

The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

Evaluation of Antimicrobial Efficacy of Root Canal Sealers against Enterococcus faecalis: A Comparative Study.

AIM: The study aimed to evaluate the efficacy of root canal sealer's antimicrobial activity against Enterococcus faecalis. MATERIALS AND METHODS: Root canal sealers with the brands Endoflas FS, AH Plus, and Tubli-Seal EWT were selected. Enterococcus faecalis organisms' zone of inhibition was measured. Tukey post hoc tests and one-way analysis of variance (ANOVA) were used to compare the data among study groups and within its group. The data were said to be statistically significant with an established p-value less than 0.05. RESULTS: The maximum zone of inhibition (23.20 ± 1.202 mm) was shown by Endoflas FS sealer; AH Plus and Tubli-Seal showed the inhibition zone of (18.42 ± 1.023) and (16.88 ± 0.962) respectively, following Endoflas FS. The ANOVA test showed p < 0.0001, which is highly statistically significant. AH Plus and Endoflas FS showed a statistically significant difference of 0.04 and 0.001 in between groups, and there was no statistically significant difference in the Tubli-Seal group from Tukey post hoc test. CONCLUSION: The study showed that Endoflas FS sealer has a significant antimicrobial effect against E. faecalis. CLINICAL SIGNIFICANCE: In clinical situation, despite perfect che-momechanical root canal preparation, persistence of microorganisms may reinfect the root canal. Therefore, endodontic root canal sealers play a major role in the eradication of bacteria. The polymicrobial nature of endodontic infection plays a main role during the usage of endodontic sealer with antimicrobial agents, which in turn reduces the failure of endodontic treatment.

Zinc oxide eugenol paste jeopardises the adhesive bonding to primary dentine.

AIM: This was to evaluate the influence of root canal filling pastes on microshear bond strength (µSBS) of an adhesive system to primary dentine. METHODS: Human (32) primary molars were randomly assigned into four experimental groups (n = 8): zinc oxide eugenol paste (ZOE); iodoform paste (Guedes-Pinto paste); calcium hydroxide paste thickened with zinc oxide; and no filling paste (control). Flat dentine surfaces were covered with a 1 mm-thick layer of the pastes for 15 min at 37 °C. The pastes were mechanically removed from dentine surfaces, followed by rinsing and drying. After adhesive application (Adper Single Bond 2, 3M ESPE), starch tubes were placed over pre-treated dentine and filled with composite resin (Z250, 3M ESPE). The µSBS test was performed after 24 h of water storage at 37 °C. The failure mode was evaluated using a stereomicroscope. The µSBS values (MPa) were analysed with one-way ANOVA and Tukey post-hoc tests (α = 0.05). RESULTS: The lowest µSBS values were achieved when ZOE was used. No difference was found among other filling pastes compared with control group. All specimens showed adhesive/mixed failures. CONCLUSIONS: Zinc oxide eugenol paste negatively influenced the bond strength of adhesive systems to primary dentine. Iodoform-based Guedes-Pinto paste and calcium hydroxide paste thickened with zinc oxide did not influence the microshear bond strength values.

Biological response to self-etch adhesive after partial caries removal in rats.

OBJECTIVES: The purposes of this study were to evaluate a model of slow caries progression and to investigate the performance of a self-etch adhesive system for partial caries removal. MATERIALS AND METHODS: Rat molars were infected with Streptococcus sobrinus 6715 culture. Different time points were analyzed: days 78, 85, and 95 (± 2). After this, the samples were processed for morphological analysis. Additionally, the first molars were restored with zinc oxide and eugenol (IRM™; Dentsply; Brazil) or adhesive system (Clearfil SE Bond™; Kuraray Medical; Japan) 78 days after caries induction. After, 3 or 15 days post-treatment, the animals were euthanized, and their mandibles were processed for morphological analysis, classified by means of scores, and submitted to statistical analysis. Subsequently, immunohistochemical analysis was performed for osteonectin (OSN) and transforming growth factor-ß1 (TGF-ß1) expression. RESULTS: According to the caries induction model used, on day 95 greater inflammatory infiltration (p < 0.001), and more extensive degradation of secondary/primary dentin were demonstrated than on day 78 (p < 0.05). Furthermore, the restorative materials presented similar performance (p > 0.05) and proved to be fundamental to control the carious lesion. The TGF-ß1 and OSN were shown to be active during the caries process. CONCLUSIONS: The slow caries lesion model was feasible for morphological analysis of the dentin-pulp complex. The self-etch adhesive system triggered no acute inflammatory infiltration or pulp necrosis, instead it seemed to stimulate early pulp repair. CLINICAL RELEVANCE: Clearfil SE Bond™ applied directly on caries-affected dentin did not predispose to pulp inflammation; instead, it appeared to provide early biological benefits.

Influence of the addition of microsphere load amoxicillin in the physical, chemical and biological properties of an experimental endodontic sealer.

AIM: To develop an endodontic sealer with amoxicillin-loaded microsphere and to evaluate its properties. METHODS: Experimental sealer was obtained by mixing 70wt% UDMA, 15wt% GDMA and 15wt% BISEMA. In addition, CQ, DHEPT and PB were incorporated at 1 mol% and 0.01wt% BHT and 10wt% YbF3. Microspheres were produced by drying in spray dryer. Two experimental groups (10 and 15wt% of microspheres) and one control group (without microspheres) were formulated. The sealers were evaluated for the degree of conversion (n=3), degradation in solvent (n=3), drug release profile (n=3), antimicrobial activity (n=3), flow (n=3), film thickness (n=3) and cytotoxicity (n=3). Data were analyzed by ANOVA and Tukey with significance level of 5%. RESULTS: Microespheres presented a mean size of 2.664µm. Immediate degree of conversion ranged from 51.73% to 55.13% and the 24h degree of conversion ranged from 60.79% to 73.80%. Upon solvent degradation 54.44% and 56.21% reduction in hardness were observed for 10% and 15% concentrations respectivelly. The drug release profile showed an average release of 73.76% of the drug in 96h. Significant reduction in antimicrobial activity was observed for 10% concentration after 24h, 48h and 96h compared to control. The flow and film thickness showed values in accordance to the ISO 6876. Cytotoxicity showed high cellular viability. CONCLUSION: The addition of up to 10% of microspheres containing amoxicillin presented antimicrobial activity and did not alter the properties of the experimental endodontic cement. CLINICAL SIGNIFICANCE: Amoxicillin microspheres with its antimicrobial activity in root canal sealers could reduce reintervations in endodontics when persistent bacteria or reinfection takes place in root canal system.

Zirconia-incorporated zinc oxide eugenol has improved mechanical properties and cytocompatibility with human dental pulp stem cells.

OBJECTIVE: Zinc oxide eugenol (ZOE) is widely used as a therapeutic dental restorative material. However, ZOE has poor mechanical properties and high cytotoxicity toward human dental pulp stem cells (hDPSCs) due to the release of Zn ions. In this study, zirconia-incorporated ZOE (ZZrOE) was developed to reduce the cytotoxicity and improve the mechanical properties of ZOE with sustained therapeutic effects on inflamed hDPSCs in terms of inflammatory gene expression levels compared with those of the original material. METHODS: After the setting time and mechanical properties of ZZrOE incorporating varying amounts of zirconia (0, 5, 10, and 20wt% in powder) were characterized, the surface morphology and composition of the resulting ZZrOE materials were investigated. The ions and chemicals released into the cell culture medium from ZOE and ZZrOE (3cm2/mL) were measured by inductively coupled plasma atomic emission spectroscopy and gas chromatography, respectively. After testing cytotoxicity against hDPSCs using the above extracts, the therapeutic effects on lipopolysaccharide-inflamed hDPSCs in terms of compromising the upregulation of inflammatory response-related mRNA expression were tested using real-time PCR. RESULTS: ZZrOE 20% exhibited increased compressive strength (∼45%), 3-point flexural strength (∼150%) and hardness (∼75%), as well as a similar setting time (∼90%), compared with those of ZOE. After the rough surface of ZZrOE was observed, significantly fewer released Zn ions and eugenol (∼40% of that from ZOE) were detected in ZZrOE 20%. ZZrOE showed less cytotoxicity because of the lower amount of Zn ions released from ZOE while showing sustained inhibition of inflammatory marker (e.g., interleukin 1ß, 6 and 8) mRNA levels. SIGNIFICANCE: The improved mechanical properties and cytocompatibility, as well as the sustained therapeutic effects on inflamed hDPSCs, were investigated in ZZrOE compared with those of ZOE. Therefore, ZZrOE has the potential to be used as an alternative to ZOE as a dental restorative material.

Evaluation of physical-mechanical properties, antibacterial effect, and cytotoxicity of temporary restorative materials

Abstract The objective of this study was to compare selective physical-mechanical properties, antibacterial effects and cytotoxicity of seven temporary restorative materials (TRM): five resin-based materials [Bioplic (B), Fill Magic Tempo (FM), Fermit inlay (F), Luxatemp LC (L) and Revotek LC (R)], and zinc oxide-eugenol cement (IRM) and glass ionomer cement (GIC) as the controls. Material and methods The physical-mechanical properties were evaluated by determining microleakage (ML), ultimate tensile strength (UTS) and Shore D hardness (SDH). In addition, the polymerization rate (Pr-1), depth of cure (DC), water sorption and solubility (WS/SL) were evaluated. The antimicrobial effects of the materials were assessed by biofilm accumulation of Streptococcus mutans (BT) and the direct contact test (DCT) by exposure to Enterococcus faecalis for 1 and 24 h, and cytotoxicity by MTT assay. The data were analyzed by ANOVA or Kruskall-Wallis tests, and a complementary post-hoc method (p<0.05). Results Group B, followed by FM and GIC had significantly lower percentages of microleakage in comparison with the other groups; Groups FM and L showed the highest WS, while Groups R and FM showed the significantly lowest SL values (p<0.05). Group R showed the statistically highest UTS mean and the lowest DC mean among all groups. Group F showed the lowest S. mutans biofilm accumulation (p=0.023). Only the Group L showed continued effect against E. faecalis after 1 h and 24 h in DCT. The L showed statistically lower viability cell when compared to the other groups. Conclusions These findings suggest the antibacterial effect of the temporary materials Fill Magic and Bioplic against S. mutans, while Luxatemp showed in vitro inhibition of S. mutans biofilm accumulation and E. faecalis growth. Regarding the cell viability test, Luxatemp was the most cytotoxic and Fill Magic was shown to be the least cytotoxic.

Clinical and radiographic evaluation of pulpectomy in primary teeth: a 18-months clinical randomized controlled trial.

BACKGROUND: To avoid untoward changes when primary teeth are replaced by permanent teeth, resorption of the material used in primary teeth root canal filling should occur at the same rate as root resorption. The Aim of this study was to compare the success rates of a mixed primary root canal filling (MPRCF, ingredients: zinc oxide-eugenol [ZOE], iodoform, calcium hydroxide) to those of ZOE and Vitapex in pulpectomised primary molars. METHODS: One hundred and sixty primary molars from 155 children (average age 5.88 ± 1.27 years) underwent two-visit pulpectomy using one of the three materials. The clinical and radiographic findings at 6, 12 and 18 months were assessed. RESULTS: At 6 and 12 months, the MPRCF and ZOE success rates were 100%. The Vitapex group showed clinical success rate and radiographic success rate of 100 and 94.5% at 6 months, and 80.4 and 60.7% at 12 months. The 18-month clinical success rates of the MPRCF, ZOE and Vitapex were 96.2, 92.2 and 71.4% and radiographic success rates were 92.5, 88.2 and 53.6%, respectively. There was a statistically significant difference in the success rates between MPRCF and Vitapex and no significant differences between MPRCF and ZOE. More MPRCF were resorbed at same rate with roots than ZOE and Vitapex. Early resorption of root filling resulted in more failure. CONCLUSIONS: The mixture of ZOE, iodoform and calcium hydroxide can be considered an effective root canal filling material in pulp involved primary teeth and had no adverse effect on tooth replacement. TRIAL REGISTRATION: ChiCTR-TRC-14004938 . Registered 13 July 2014.

Protein Activation in Periapical Reaction to Iodoform Containing Root Canal Sealer.

OBJECTIVES: An association between root canal sealers and periapical lesions in primary dentition has been suggested, yet the chemical-protein interactions that may be involved in it have not been studied. The present study explored root sealer components' effect on periapical tissue proteins using bioinformatics tools. STUDY DESIGN: For each chemical component of Endoflas F.S. root sealing material we identified the known and predicted target proteins, using STITCH (search tool for interactions of chemicals http://stitch.embl.de/ ). Identified target proteins were grouped into functional categories using the annotation clustering tool from DAVID, the Database for Annotation, Visualization and Integrated Discovery ( http://david.abcc.ncifcrf.gov/ ). STRING Protein-Protein Interaction network database identified associations between the proteins. RESULTS: Sixteen proteins identified with STITCH served as input to DAVID annotation clustering tool. Only ZnO and Eugenol targeted proteins had statistically significant annotations. Gene Ontology terms of ZnO and Eugenol targeted proteins demonstrated that these proteins respond to mechanical stimulus and to oxidative stress. They highlight these proteins' role in the positive regulation of transcription, gene expression, cell proliferation and apoptosis, and their complementary role in the negative regulation of cell death. CONCLUSION: When stimulated by Zinc Oxide, Eugenol and Calcium hydroxide, chemical-protein and subsequent protein-protein interactions result in cell proliferation in the periapical area. Our findings indicate that certain root sealers components may cause enlargement of the permanent tooth follicle. Dentists should be aware of this phenomenon and radiographically monitor root canal treated teeth until shedding.

Antibiofilm Activity of Five Different Endodontic Filling Materials Used in Primary Teeth Using Confocal Laser Scanning Microscopy.

PURPOSE: The purpose of this study was to evaluate the effect of five endodontic materials for primary teeth on in vitro mixed-species biofilms. METHODS: Zinc oxide eugenol (ZOE) cement, Vitapex, Calen paste thickened with zinc oxide (ZO), pure calcium hydroxide (Ca(OH)2) paste, and iodoform were evaluated. Sterile water was used as a control. Mixed-species biofilm was incubated in anaerobic conditions for 21 days. The biofilm specimens were placed in contact with the endodontic materials for periods of seven and 30 days. The biofilm was studied by using confocal laser scanning microscopy. The cell viability ratio was calculated. The results were analyzed using analysis of variance and Tukey tests. RESULTS: There was a statistically significant difference between groups at both seven and 30 days (F equals 73,073, P=0.00). After 30 days, 69 percent, 51 percent, and 35 percent of the biofilm volume fluoresced red, indicating the proportion of bacteria killed by iodoform, Vitapex, and ZOE cement, respectively. Calen plus ZO and pure Ca(OH)2 paste were the least effective materials against the biofilms. CONCLUSIONS: Pure iodoform paste and iodoform containing Vitapex were the most effective materials against the biofilms. Vitapex appears to be a suitable endodontic material for primary teeth.