Postoperative pain intensity and incidence following single visit root canal treatment with different obturation techniques: a randomized clinical trial.

Background: There are few studies in the literature about the effect of obturation techniques on postoperative pain. Besides, GuttaFlow2 was used for the first time in this study regarding postoperative pain. This study aimed to compare the postoperative pain levels and incidence following single-visit root canal treatment with different canal filling techniques; cold lateral compaction (CLC), thermoplasticised solid-core carrier (GuttaCore) based filling and cold free-flow compaction (GuttaFlow2) technique. Methods: The patients (n = 93) having single-rooted teeth with a single canal diagnosed with asymptomatic irreversible pulpitis or single-rooted vital teeth with a single canal requiring endodontic treatment because of prosthetic reasons were enrolled in this study. Patients were randomized into three groups (n = 31) according to the obturation technique. A single operator performed all the treatments in a single visit. Data on obturation levels, postoperative pain and analgesic intake frequency were recorded at postoperative 6, 12 and 24 h and daily afterward until the 7th day. Postoperative pain was measured by visual analogue scale (VAS). The date were statistically analyzed with chi-squared tests (for the analyses of the categorical data), the nonparametric Kruskal-Wallis test (for the comparisons of VAS score) and with the Friedman test (for the assessments of the changes in VAS scores over time). Results: The GuttaCore group recorded the higher pain levels, except first 12 h, on the other hand, the GuttaFlow2 group recorded the lower pain levels at all time periods. Significant differences occurred among the groups during the first 4 days (p < 0.05), except at 12 h (p = 0.054). The patients in the CLC and GuttaFlow2 groups did not need to use the prescribed analgesic; however, one patient in the GuttaCore group used it once. Conclusions: Postoperative pain levels following root canal therapy were affected by the obturation technique especially first 4 days following obturation.

Are aerosol control devices effective in preventing the spread of dental aerosol?

Background: In dental clinics, aerosols produced from dental instruments have become a matter of concern following breakout of coronavirus disease 19 (COVID-19) evolving into a pandemic. This study compared aerosol reduction systems and in terms of their ability to reduce Enterococcus faecalis (E. faecalis) contaminated aerosol in a simulated dental office set-up. Methods: Closed clinic model with manikin and mandibular molar typodont was simulated. For 10 min, the air and water dispersed by the rotating bur mounted on an aerator was contaminated by pouring the suspension containing 1-3 × 108 CFU/mL E. faecalis directly on the bur. During and after the procedures, the air within the cabin was also sampled. CFU count was recorded and scored. The mean CFU scores obtained from agar plate count and air sampling device was compared using Kruskal-Wallis H test among groups with 5% significance threshold. Results: The use of WS Aerosol Defender device led to greater CFU scores on the agars levelled to patient's chest compared to other directions (p = 0.001). Combined use of VacStation and WS Aerosol Defender resulted in significantly decreased CFU score in the air samples compared to experimental and positive control groups (p = 0 < 0.05). Conclusions: Although the devices prevented the spread of aerosol around the patient to some extent, they could not completely eliminate the contaminated aerosol load in the cabin environment.

Fe-based layered double hydroxides for removing arsenic from water: sorption-desorption-regeneration.

Since the presence of arsenic in the waters of the world causes serious health effects on people, it is very important to remove it. Layered double hydroxides have a high surface area and high anion exchange capacity, and because of this feature, it is a potential adsorbent to remove arsenic. For regeneration and reuse of adsorbents, researchers in some limited studies have used agents such as acids and alkalis. Media replacement accounts for approximately 80% of the total operational and maintenance costs. In this paper, an adsorption/desorption/regeneration study was carried out with MgFeHT to determine the desorption properties of the adsorbent and to examine its reusability. The best alkaline desorption solution was determined from two different alkaline solutions: NaOH and KH2PO4. As(V) adsorption capacity of the MgFeHT at different pH (3-12) using the arsenic aqueous solution (with 2,000 µg As(V)/L) was evaluated. For the adsorption process, the experimental data are fitted well with the pseudo-second-order kinetic model and the Langmuir model. Moreover, the concentration of 2,000 µg/L arsenic was reduced to below the legal limit determined by the WHO (<10 µg/L). The regeneration studies were conducted on the adsorptive media used in the arsenic removal system. The regeneration efficiency of As(V) was maintained 98.5% for four regeneration cycles using 0.5 M NaOH. MgFeHT was successfully regenerated with an aqueous solution of NaOH and was reused with a small loss of sorption efficiency.

Nonsurgical Retreatment Using Regenerative Endodontic Protocols: A Case Report.

AIM AND OBJECTIVE: The aim of this case report was to describe regenerative endodontic procedures (REPs) of the previously treated mature teeth with long-term results. BACKGROUND: Regenerative endodontic procedures are aimed to treat apical periodontitis and regenerate the pulp-dentin complex in necrotic teeth. However, there is no consensus in using REPs in the previously treated mature teeth. The aim of this case report was to describe REPs of the previously treated mature teeth with long-term results. CASE DESCRIPTION: A 25-year-old woman presented pain on chewing on 15 and swelling (WHO numbering system). The tooth had been endodontically treated and restored 4 years ago. After removing the old root canal filing, the roots were irrigated with 2.5% sodium hypochlorite and 17% EDTA using sonic activation. Calcium hydroxide (CH) was used as medicament for 3 weeks. At the second visit, CH was removed, and canals were irrigated as like as the first visit. Apical bleeding was induced, and concentrated growth factors (CGFs) were placed inside the root canal. The tooth has been followed up to 3 years. CONCLUSION: The tooth was functional and asymptomatic at the recall visits. Since the first-year follow-up, the tooth responded to the electric pulp test and the thermal test. Radiological examinations revealed healing of apical lesion and hard tissue deposition. CLINICAL SIGNIFICANCE: Regenerative endodontic procedures can offer an advantage over traditional endodontic procedures in terms of tertiary healing, with a predictable, user-friendly procedure also for retreatment cases.

Arsenic removal from groundwater in Kütahya, Turkey, by novel calcined modified hydrotalcite.

Since arsenic is highly toxic and carcinogenic, it now causes serious health problems all over the world. Therefore, there is an urgent need to develop new techniques that are cost-effective and easily applicable to remove arsenic from contaminated waters. Layer double hydroxides have the potential to be a good adsorbent to remove arsenic from contaminated waters due to high surface area and high anion exchange capacity. In this paper, arsenic removal from water by calcined Fe-hydrotalcite (CFeHT) known as layered double hydroxide and prepared synthetically with coprecipitation method was researched. The study brings out that the effect of initial solution pH values was limited for the adsorption. The experimental study indicates that the adsorption of arsenic rapidly occured in comparison with other studies. It was determined that the pseudo-second-order kinetic model was more suitable than the first order. In isotherm studies, it was seen that the experimental data were compatible with Langmuir model. In this study was determined that CFeHT has a high arsenic removal potential. And also the concentration of the arsenic solution (600 µg/L) has been reduced below the allowable value by the World Health Organization (< 10 µg/L). The desorption test indicates that the desorption ratio of As(V) was obtained as 72.7.

Fear of happiness among college students: The role of gender, childhood psychological trauma, and dissociation.

AIMS: This study aimed to evaluate the fear of happiness among college students and its relationship to gender, childhood psychological trauma, and dissociation. SETTING AND DESIGN: College students were addressed as study population, and a relational screening method was implemented. MATERIALS AND METHODS: Among 184 participants, 93 (50.5%) were women. The Fear of Happiness Scale (FHS), the Childhood Trauma Questionnaire (CTQ), and the Dissociative Experiences Scale (DES) were administered to all participants. STATISTICAL ANALYSIS USED: Mann-Whitney-U and Student's t-tests were implemented for comparison of groups. Pearson correlation and stepwise multiple regression analyses were conducted to identify associations between variables. RESULTS: There were no differences on DES, FHS, and CTQ total scores between genders. DES was associated with CTQ total scores in both genders. Women had higher scores than men on childhood emotional abuse and fear of "cheerfulness ends up with bad faith." Compared to nonmembers, female dissociative taxon members had higher scores on all childhood trauma types except sexual abuse, and on all types of fear of happiness except "good fortune ends up with disaster" which was the only type of fear significantly elevated among male dissociative taxon members. A stepwise regression analysis revealed that depersonalization, childhood emotional neglect, and physical abuse predicted fear of happiness among women which was predicted by absorption among men. CONCLUSIONS: There is a relationship between childhood psychological trauma, dissociation, and fear of happiness. Women seem to be more vulnerable in this path of obsessional thinking which affects different realms in male and female genders.

Time-dependent effectiveness of the intracanal medicaments used for pulp revascularization on the dislocation resistance of MTA.

BACKGROUND: The aim of the present study was to evaluate the time-dependent effectiveness of the intracanal medicaments used in pulp revascularization on the dislocation resistance of mineral trioxide aggregate (MTA). METHODS: One hundred ninety-two extracted human maxillary incisor teeth were sectioned apically 12 mm below and coronally 2 mm above the cemento-enamel junction. Roots were enlarged to size 40 (Protaper F4). Next, Peeso reamers from #1 to #5 were used sequentially. Sodium hypochlorite (2.5 %), EDTA (17 %), and distilled water were used in final irrigation. The specimens were randomly divided into four groups (n = 48): Group 1, in which triple antibiotic paste (TAP) (ciprofloxacin + metronidazole + minocycline) was prepared and delivered into the canals using a lentulo spiral; Group 2, in which double antibiotic paste (DAP) (ciprofloxacin + metronidazole) was placed into the canals; Group 3, in which calcium hydroxide paste (CH) (calcium hydroxide + distilled water) was introduced into the roots; and Group 4 (control), in which no medicament was applied into the root canals. Then, the samples were kept in saline solution for 2, 4, and 12 weeks, after which time 16 roots were selected randomly from each group, representing the samples of each time point. After removal of the medicaments, MTA was placed into the coronal third of the roots, and the samples were incubated for 7 days. A push-out test was used to measure the dislocation resistance (DR) of MTA. The data were analyzed using a two-way ANOVA followed by Tukey's pairwise comparisons (p = 0.05). RESULTS: The time factor displayed a significant effect on the DR of MTA (p < 0.05). All medicaments resulted in significantly smaller DR values after 12 weeks compared to after 1 week (p < 0.05). A significant unfavorable effect of TAP and DAP was observed as early as 2 weeks after the application, while 2 and 4 weeks after the application of CH there was no effect on the DR of MTA. No significant differences were found between the time points in the control group (p > 0.05). CONCLUSION: The type and the intracanal duration of medicaments used for pulp revascularization should be chosen carefully to provide maximum antimicrobial effect while creating a favorable environment both for stem cell attachment and MTA adhesion.

Effect of spreader size on microleakage of roots filled with cold lateral compaction technique.

OBJECTIVES: To evaluate the effect of spreader size on apical leakage of maxillary incisor teeth. MATERIALS AND METHODS: A total of 75 permanent human teeth with no carious and no fracture or crack were used for this study. After removing the crown from the cementoenamel junction and the standardization of the root lengths, the specimens were randomly divided into five groups: Group 1 - Roots were not instrumented. Group 2 - Root canals were enlarged using the step-back technique to a #40 file and filled using cold lateral compaction (CLC) of gutta-percha (GP). Group 3 - During the filling procedure, the first spreader used was size 40. Group 4 - The first spreader used was size 35. Group 5 - The initial spreader used was size 25. The amount of leakage through the filled root canals was evaluated by computerized fluid filtration model. Statistical analyzes were done using Kruskal-Wallis test and Mann-Whitney test (P < 0.05). RESULTS: There were statistically significant differences among the groups (P < 0.05). While the uninstrumented group (Group 1) had no leakage, instrumented but not filled roots (Group 2) demonstrated the highest leakage values. There were no differences between Group 3 and 4. Group 5 showed significantly less leakage than Group 3 and 4. CONCLUSION: Spreader size used during CLC of GP appeared to be a significant factor on apical leakage of roots. Using smaller size spreader during CLC may provide relatively less leakage.

Evaluation of the smear layer removal and erosive capacity of EDTA, boric acid, citric acid and desy clean solutions: an in vitro study.

BACKGROUND: The purpose of this study was to investigate the smear layer removal and erosive capacity of various irrigation solutions with sequential use of NaOCl on instrumented root canal walls. METHODS: The root canals of single-rooted teeth were instrumented with ProTaper rotary instrument. Then, the teeth were randomly divided into five experimental groups. The root canals were irrigated with one of the following solutions (5 mL/1 min): 5% EDTA, 5% boric acid (BA), a mixture of BA and CA, 2.5% citric acid (CA) and 5% Desy Clean. After irrigating with 2.5% NaOCl and distilled water, the roots were split into two halves and each half was prepared for SEM examination. Representative photographs were taken from each third at x500 and x1000 magnifications. Double blind scoring was performed by two calibrated observers for smear layer and erosion. The scores were statistically analyzed using Kruskal-Wallis, Dunn's post hoc and Spearman's correlation tests (p = 0.05). RESULTS: There were statistically significant differences among the solutions by means of smear layer and erosion (p < 0.05). While 2.5% CA solution was the most effective solution in removal of smear layer, it was also the most erosive solution (p < 0.05). 5% Desy Clean removed smear layer effectively and caused less erosion. There was a negative, but statistically significant correlation between presence of smear layer and erosion (r = -0.684; p < 0.0001). CONCLUSION: Desy Clean can be a promising agent as an irrigation solution with optimal smear layer removal capacity and less erosive effects.

Effect of storage solutions on microhardness of crown enamel and dentin.

OBJECTIVE: The aim of this study was to determine alterations in microhardness of crown dentin and enamel, after 2 and 12-month storage in de-ionized water, 0.2% glutaraldehyde, Hanks' Balanced Salt Solution (HBSS), 0.1% sodium hypochlorite (NaOCl) or 0.1% thymol. MATERIALS AND METHODS: Freshly extracted, nonsterile 60 intact human premolars were distributed to five groups. Six teeth from each group were evaluated after two, and other six teeth were evaluated after 12 months storage. After grinding and polishing of teeth, Vickers hardness was evaluated with making indentations on enamel and dentin, using a pyramid diamond indenter tip exerting 100 g load for 15 s. RESULTS: After 2 months storage in solutions, range of the hardness values (HV) of enamel and dentin were in between 315-357 and 64-67, respectively. However, 12 months storage of the teeth resulted in a statistically significant decrease in microhardness when compared to microhardness of teeth stored for 2 months (P = 0.001). Although the differences were not significant regarding solutions, all solutions decreased the microhardness both in enamel and dentin (P > 0.05). However, decrease in microhardness was relatively less in de-ionized water and thymol solutions while glutaraldehyde decreased microhardness the most: 63% for enamel and 53% for dentin. CONCLUSIONS: Microhardness of enamel and dentin was in an acceptable range when teeth were stored for 2 months in de-ionized water, glutaraldehyde, HBSS, NaOCl or in thymol; thus, teeth kept up to 2 months in these solutions can be used for mechanical in vitro tests. However, 12 months storage significantly decreased the microhardness of enamel and dentin.

Surface roughness and bond strength of zirconia posts to a resin cement after various surface pretreatments.

OBJECTIVE: The purpose of this study was to investigate the influence of post surface conditioning methods on the surface roughness and microtensile bond strength (µTBS) of zirconia posts to a resin cement. BACKGROUND DATA: Debonding at the post-adhesive interface is a major problem for zirconia posts. METHODS: A total of 25 zirconia posts (n=5) were prepared as follows: untreated (control, group C), airborne-particle abraded (group AA), silica coated (group SC), Nd:YAG laser irradiated (group N), and Er:YAG laser irradiated (group E). Prior to application of a dual-cured resin cement on the posts, roughness values of the post surfaces were detected with a profilometer. Specimens were then sectioned to obtain rectangular sticks for µTBS. After sticks were stored in distilled water at 37°C for 24 h, µTBS values were determined in a universal testing machine at a crosshead speed of 1 mm/min until failure. Furthermore, scanning electron microscopic (SEM) analysis was performed for one specimen of each group to evaluate the post surface morphology. One-way ANOVA and post-hoc comparison tests (α=0.05) were performed on all data. RESULTS: All surface treatment groups demonstrated significant higher µTBS values than the control group (p<0.001). The highest mean force value was observed in group SC. In addition, similar bond strength results were detected between group SC and group E (p=0.669). None of treatment groups resulted in significant improvement in roughness values of the post (p<0.05), except group N. CONCLUSIONS: All surface treatments were found to be effective methods to achieve a durable bond between zirconia posts to resin cement.