Daniel Rodrigo Herrera

Evaluation of Cytotoxicity and Physicochemical Properties of Calcium Silicate-based Endodontic Sealer MTA Fillapex

INTRODUCTION The aim of the study was to evaluate the cytotoxicity, radiopacity, pH, and flow of a calcium silicate-based and an epoxy resin-based endodontic sealer, MTA Fillapex (Angelus, Londrina, PR, Brazil) and AH Plus (Dentsply, Konstanz, Germany), respectively. METHODS Cytotoxicity, radiopacity, and flow evaluation were performed following ISO requirements. The pH level was measured at periods of 3, 24, 72, and 168 hours. Cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay to check the Balb/c 3T3 cells viability at 1- to 4-week periods. Data were statistically analyzed by analysis of variance and the Tukey test with a significance level of 5%. RESULTS In all tested periods, MTA Fillapex was more cytotoxic than AH Plus (P < .05). Although AH Plus presented higher radiopacity than MTA Fillapex (P < .05), both sealers showed minimum required values. MTA Fillapex presented alkaline pH in all experimental times, whereas AH Plus cement showed a slightly neutral pH and a flow significantly lower than that of MTA Fillapex (P < .05). CONCLUSIONS Although MTA Fillapex was more cytotoxic than AH Plus, it showed suitable physicochemical properties for an endodontic sealer.

Evaluation of cytotoxicity and up-regulation of gelatinases in fibroblast cells by three root repair materials.

AIM To investigate the effects of root repair materials on the cytotoxicity and gelatinolytic activity of matrix metalloproteinases (MMPs) in 3T3 fibroblasts. METHODOLOGY Fibroblasts (3T3, 3 × 10(5) cells per well) were incubated with elutes of calcium hydroxide (Biodinâmica, Ibiporã, PR, Brazil), EndoBinder (Binderware, São Carlos, SP, Brazil) and mineral trioxide aggregate (MTA) (Angelus, Londrina, PR, Brazil) for 24 h. The cytotoxicity of all root repair materials was determined using the MTT assay. Supernatants of cell cultures incubated with materials were collected after 24 h to determine the levels of MMP-2 and MMP-9 gelatinolytic activity by gelatin zymography. Data were analysed using anova and Tukeys test. RESULTS Cells secreted MMP-2 after 24 h with calcium hydroxide inducing significantly greater MMP-2 expression in relation to the control and the other root repair materials (P < 0.05). The cytotoxicity results revealed that there was no significant difference in the cell viability of MTA, EndoBinder and the control group. However, there was a significantly reduced cell viability of 3T3 fibroblasts in association with calcium hydroxide (P < 0.05). CONCLUSIONS Calcium hydroxide was associated with significantly less cell viability when compared with EndoBinder and MTA. All materials had gelatinolytic activity for MMP-2 with calcium hydroxide being associated with the greatest activity.

Effect of water storage and heat treatment on the cytotoxicity of soft liners.

OBJECTIVE To evaluate the effect of water storage time on the cytotoxicity of soft liners. METHODS Sample discs of soft liners Dentusoft, Dentuflex, Trusoft, Ufi-Gel-P and denture base acrylic resin Lucitone-550 were prepared and divided into four groups: GN: No treatment, G24: Stored in water at 37°C for 24 h; G48: Stored in water at 37°C for 48 h, GHW: Immersed in water at 55°C for 10 min. To analyse the cytotoxic effect, three samples of each group were placed in tubes with Dubelccos Modified Eagle Mediums and incubated at 37°C for 24 h. During this period, the toxic substances were leached to the culture medium. The cytotoxicity was analysed quantitatively by the incorporation of radioactivity (3)H-thymidine checking the number of viable cells (synthesis of DNA). The data were statistically analysed using two-way anova and Tukeys honestly significant difference tests (α = 0.05). RESULTS Treatments did not reduce the cytotoxicity effect of the soft liners (p > 0.05). It was found that Ufi-Gel-P had a non-cytotoxic effect, Trusoft had a slightly cytotoxic effect, Dentuflex had a moderated cytotoxic effect, Dentusoft alternated between slightly and non-cytotoxic effect, and Lucitone-550 had non-cytotoxic effect when stored in water for 48 h. CONCLUSION The effect of water storage and the heat treatment did not reduce the cytotoxicity of the soft liners.

Efficacy of different final irrigant activation protocols on smear layer removal by EDTA and citric acid

The aim of this study was to evaluate the influence of different activation protocols for chelating agents used after chemo‐mechanical preparation (CMP), for smear layer (SL) removal. Forty‐five single‐rooted human premolars with straight canals and fully formed apex were selected. The specimens were randomly divided into three groups depending on the chelating agent used for smear layer removal: distilled water (DW, control group); 17% ethylenediaminetetraacetic acid (EDTA); and 10% citric acid (CA). Each group was further divided into three subgroups according to the activation protocol used: no‐activation (NA), manual dynamic activation (MDA), or sonic activation (SA). After CMP, all specimens were sectioned and processed for observation of the apical thirds by using scanning electron microscopy (SEM). Two calibrated evaluators attributed scores to each specimen. The differences between activation protocols were analyzed with Kruskal‐Wallis and Mann‐Whitney U tests. Friedman and Wilcoxon signed rank tests were used for comparison between each root canal third. When chelating agents were activated, either by MDA or SA, it was obtained the best cleaning results with no significant difference between EDTA and CA (P > 0.05). Sonic activation showed the best results when root canal thirds were analyzed, in comparison to MDA and NA groups (P < 0.05). The activation of chelating agents, independent of the protocol used, benefits smear layer removal from root canals. Microsc. Res. Tech. 76:364–369, 2013.

Evaluation of cytotoxicity, antimicrobial activity and physicochemical properties of a calcium aluminate-based endodontic material

A calcium aluminate-based endodontic material, EndoBinder, has been developed in order to reduce MTA negative characteristics, preserving its biological properties and clinical applications. Objectives The aim of this study was to evaluate the cytotoxicity, antimicrobial activity, pH, solubility and water sorption of EndoBinder and to compare them with those of white MTA (WMTA). Material and Methods Cytotoxicity was assessed through a multiparametric analysis employing 3T3 cells. Antimicrobial activity against Enterococcus faecalis (ATCC 29212), Staphylococcus aureus. (ATCC 25923) and Candida albicans (ATCC 10556) was determined by the agar diffusion method. pH was measured at periods of 3, 24, 72 and 168 hours. Solubility and water sorption evaluation were performed following ISO requirements. Data were statistically analyzed by ANOVA and Tukey`s test with a significance level of 5%. Results EndoBinder and WMTA were non-cytotoxic in all tested periods and with the different cell viability parameters. There was no statistical differences between both materials (P>.05). All tested materials were inhibitory by direct contact against all microbial strains tested. EndoBinder and WMTA presented alkaline pH in all tested times with higher values of pH for WMTA (P<.05). Both materials showed values complying with the solubility minimum requirements. However, EndoBinder showed lower solubility than WMTA (P<.05). No statistical differences were observed regarding water sorption (P>.05). Conclusion Under these experimental conditions, we concluded that the calcium aluminate-based endodontic material EndoBinder demonstrated suitable biological and physicochemical properties, so it can be suggested as a material of choice in root resorption, perforations and root-end filling.

Evaluation of different treatment methods against denture stomatitis: a randomized clinical study

OBJECTIVE The aim of this clinical study was to determine the efficacy of Uncaria tomentosa (cats claw) against denture stomatitis (DS). STUDY DESIGN Fifty patients with DS were randomly assigned into 3 groups to receive 2% miconazole, placebo, or 2% U tomentosa gel. DS level was recorded immediately, after 1 week of treatment, and 1 week after treatment. The clinical effectiveness of each treatment was measured using Newtons criteria. Mycologic samples from palatal mucosa and prosthesis were obtained to determinate colony forming units per milliliter (CFU/mL) and fungal identification at each evaluation period. RESULTS Candida species were identified with HiCrome Candida and API 20C AUX biochemical test. DS severity decreased in all groups (P < .05). A significant reduction in number of CFU/mL after 1 week (P < .05) was observed for all groups and remained after 14 days (P > .05). C albicans was the most prevalent microorganism before treatment, followed by C tropicalis, C glabrata, and C krusei, regardless of the group and time evaluated. U tomentosa gel had the same effect as 2% miconazole gel. CONCLUSIONS U tomentosa gel is an effective topical adjuvant treatment for denture stomatitis.

Furcal-perforation repair with mineral trioxide aggregate: Two years follow-up.

Furcal perforations are significant iatrogenic complications of endodontic treatment and could lead to endodontic failure. Mineral trioxide aggregate (MTA) has been regarded as an ideal material for perforation repair, retrograde filling, pulp capping, and apexification. This case report describes a furcal perforation in a maxillary first molar, which was repaired using MTA. The tooth was endodontically treated and coronally restored with resin composite. After 2 years, the absence of periradicular radiolucent lesions, pain, and swelling along with functional tooth stability indicated a successful outcome of sealing the perforation using MTA.

Effectiveness of nano-calcium phosphate paste on sensitivity during and after bleaching: a randomized clinical trial

The study aimed to evaluate the effectiveness of in-office bleaching and associated tooth sensitivity on application of nano-calcium phosphate paste as desensitizing agent. Bleaching was performed with 35% hydrogen peroxide gel in 40 patients who were randomly divided into placebo and nano-calcium phosphate paste groups. Bleaching efficacy (BE) was evaluated using a value-oriented Vita shade guide. Tooth sensitivity was recorded using a numeric rating scale (0-4) during bleaching and up to 48 h after each session. The primary outcome of absolute risk of tooth sensitivity was compared using the Fishers exact test (α = 0.05). The intensity of tooth sensitivity and the efficacy of in-office bleaching were also statistically evaluated. No significant differences in absolute risk and intensity of tooth sensitivity were detected between the groups (p = 1.0 and p = 0.53, respectively). BE was also found to be similar between the groups (p = 0.67). Although the use of a nano-calcium phosphate paste associated with fluoride and potassium nitrate did not influence the whitening outcome, but it also did not reduce bleaching-induced tooth sensitivity.

Efficacy of ethylene‐diamine‐tetra‐acetic acid associated with chlorhexidine on intracanal medication removal: A scanning electron microscopy study

The aim of this study was to evaluate the effectiveness of 17% ethylene‐diamine‐tetra‐acetic acid (EDTA) used alone or associated with 2% chlorhexidine gel (CHX) on intracanal medications (ICM) removal. Sixty single‐rooted human teeth with fully formed apex were selected. The cervical and middle thirds of each canal were prepared with Gates Glidden drills and rotary files. The apical third was shaped with hand files. The specimens were randomly divided into two groups depending on the ICM used after instrumentation: calcium hydroxide Ca(OH)2+CHX or Ca(OH)2+sterile saline (SS). After seven days, each group was divided into subgroups according to the protocol used for ICM removal: instrumentation and irrigation either with EDTA, CHX+EDTA, or SS (control groups). All specimens were sectioned and processed for observation of the apical thirds by using scanning electron microscopy. Two calibrated evaluators attributed scores to each specimen. The differences between the protocols for ICM removal were analyzed with Kruskal‐Wallis and Mann‐Whitney U tests. Friedman and Wilcoxon signed rank tests were used for comparison between the score of debris obtained in each root canal third. Remains of Ca(OH)2 were found in all specimens independently of the protocol and ICM used (P > 0.05). Seventeen percent EDTA showed the best results in removing ICM when used alone (P < 0.05), particularly in those associated with CHX. It was concluded that the chelating agent 17% EDTA significantly improved the removal of ICM when used alone. Furthermore, the type of the vehicle associated with Ca(OH)2 also plays a role in the ICM removal. Microsc. Res. Tech. 77:735–739, 2014.

Antimicrobial activity and substantivity of Uncaria tomentosa in infected root canal dentin.

The aim of this study was to analyze the antimicrobial activity and substantivity of Uncaria tomentosa Willd DC (cats claw, CC) in root dentin contaminated with Enterococcus faecalis. Forty-eight human premolars were contaminated with E. faecalis (ATCC 29212) and randomly divided into four groups according to the irrigant used during chemomechanical preparation (CMP): CC group: 2% CC gel; CHX group: 2% chlorhexidine digluconate gel (CHX); NaOCl group: 5.25% sodium hypochlorite (NaOCl); and SS group: sterile saline (SS). Microbiological samples were collected before (S1) and after (S2) CMP and after 7 days (S3). Colony-forming units (CFU/mL) at the different sampling times and comparisons among the groups were statistically analyzed by Wilcoxon and Kruskal-Wallis tests (p < 0.05). Significant bacterial reduction was achieved in all groups after CMP (p < 0.05). Results show no significant difference between S3 and S2 (p > 0.05) in the CC and CHX groups. Bacterial load was higher in S3 than in S2 samples (p < 0.05) in the NaOCl and SS groups. Our results suggest antibacterial effect of 2% CC gel against E. faecalis in infected dentin, in addition to antibacterial substantivity of 2% CC and 2% CHX up to 7 days.