In vitro evaluation of the efficacy of different protocols on calcium hydroxide dressing removal

Objective: To compare in vitro irrigation systems’ efficacy in removing calcium hydroxide paste (Ca(OH)2) in single-root teeth. Methods: Sixty permanent teeth were prepared using ProTaper® rotatory instruments, up to F3. Specimens were split longitudinally into two halves, and two grooves located in the apical and coronal zones were created. Ca(OH)2 application into the grooves was assessed by radiographic and photographic methods. After the halves were reassembled in a silicone mold, teeth were randomly divided into experimental groups (n=15), testing Ca(OH)2 removal: 1 – CanalBrush™; 2 – E1 – Irrisonic tip; 3 – manual dynamic irrigation (MDI); 4 – XP-endo Finisher® (XP). A total volume of 10 mL of 2.5% sodium hypochlorite was used in each tooth. Finally, all groups were scored regarding the Ca(OH)2 remnants using the same methods as before. Statistical analysis was conducted using the Kruskal-Wallis test followed by Mann-Whitney U tests (with Bonferroni correction). A value of p<0.05 was considered statistically significant. Results: None of the techniques demonstrated 100% efficacy in both regions. CanalBrush™ was more effective in the apical region. Overall, E1 – Irrisonic tip and CanalBrush™ removed significantly more Ca(OH)2 than MDI and XP-endo Finisher® (p<0.05). Conclusion: Globally, E1 – Irrisonic tip and CanalBrush™ were more effective, although without statistically significant differences between them.

A quadratic analytical solution of root pressure generation provides insights about bamboo and other species

We derived a steady-state model of whole root pressure generation through the combined action of all parallel segments of fine roots. This may be the first complete analytical solution for root pressure, which can be applied to complex roots/shoots. The osmotic volume of a single root is equal to that of the vessel lumen in fine roots and adjacent apoplastic spaces. Water uptake occurs via passive osmosis and active solute uptake (J_s^*, osmol s-1), resulting in the osmolal concentration Cr (mol·kg-1 of water) at a fixed osmotic volume. Solute loss occurs via two passive processes: radial diffusion of solute Km (Cr-Csoil), where Km is the diffusional constant and Csoil is the soil-solute concentration) from fine roots to soil and mass flow of solute and water into the whole plant from the end of the fine roots. The proposed model predicts the quadratic function of root pressure P_r^2+bP_r+c=0, where b and c are the functions of plant hydraulic resistance, soil water potential, solute flux, and gravitational potential. The present study investigates the theoretical dependencies of Pr on the factors detailed above and demonstrates the root pressure-mediated distribution of water through the hydraulic architecture of a 6.8-m-tall bamboo shoot.

Void characteristics and tortuosity of calcium silicate-based cements for regenerative endodontics: a micro-computed tomography analysis

Background Internal voids of materials can serve a hub for microorganism and affect the sealing ability. This study aimed to evaluate the sealing performance of calcium silicate-based cements in immature teeth treated with regenerative endodontics. Methods Twenty single root canals from immature permanent premolars were prepared using regenerative endodontic protocols. The root canals were randomly divided into two groups and sealed with mineral trioxide aggregate (MTA) and Biodentine (BD). The teeth were kept in humid environment for 7 days and scanned using micro-computed tomography. The voids within the cements were segmented and visualized using image processing, incorporating the modified Otsu algorithm. The porosity of each sample was also calculated as the ratio between the number of voxels of voids and the volume of the cements. Tortuosity was also calculated using the A-star algorithm. Results Voids larger than 70 μm were predominantly observed in the top and interfacial surface of cements. The others were evenly distributed. MTA and BD showed the same level of porosity and tortuosity at interfacial surfaces. In inner surfaces, MTA showed more less porosity and tortuosity compared to BD (p < 0.05). Conclusions There were no differences in sealing performance between MTA and BD.

On iterative techniques for estimating all roots of nonlinear equation and its system with application in differential equation

In this article, we construct a family of iterative methods for finding a single root of nonlinear equation and then generalize this family of iterative methods for determining all roots of nonlinear equations simultaneously. Further we extend this family of root estimating methods for solving a system of nonlinear equations. Convergence analysis shows that the order of convergence is 3 in case of the single root finding method as well as for the system of nonlinear equations and is 5 for simultaneous determination of all distinct and multiple roots of a nonlinear equation. The computational cost, basin of attraction, efficiency, log of residual and numerical test examples show that the newly constructed methods are more efficient as compared to the existing methods in literature.

Canal Configuration of Maxillary Premolars in Cukurova Population: A CBCT Analysis

Summary Background/Aim: Aim of this study was to evaluate the anatomy of root-canal systems and numbers of permanent maxillary premolars’ roots and canals, using cone beam computed tomography scans. Material and Methods: In this retrospective and observational study, maxillary right/left and first/second premolars of patients who were screened with cone beam computed tomography for various reasons in a Turkish dental school, were examined. Evaluated parameters were age, gender, canal configuration (Vertucci classification) and numbers of roots and canals. Chi-square test was used for statistical analysis. The level of significance was set at p<0.05. Results: A total of 1086 maxillary premolars including 555 first premolars and 531 second premolars were examined in 331 patients (186 female, 145 male). Presence of two roots was shown in 75% of first premolars. 76.3% of second premolars were found to have a single root. Most common canal configuration was type IV (73.2%) for first premolars and type II (32.4%) for second premolars. There was a significant relationship between gender and numbers of first and second premolars’ roots and canals. Conclusions: High heterogeneity of maxillary premolar root-canal system anatomy should be considered during endodontic treatment.

Application of Optimal Combined Microfertilizers of Boron, Molybdenum, and Copper Improves Root Tuber Yield Trait and Photosynthetic Response Characteristics in Pseudostellaria heterophylla

In the actual cultivation process, blind fertilizer application was widespread, resulting in a serious decline in the yield of Pseudostellaria heterophylla. We used the 3414 fertilizer experiment design to study the effects of combined Boron (B), Molybdenum (Mo), and Copper (Cu) on the growth indexes, diurnal changes of photosynthesis, and rapid fluorescence induction dynamics in P. heterophylla. Our results show that the optimal combination of B, Mo, and Cu simultaneously promoted the growth of underground and aboveground parts, and significantly improved the quality of single root tuber and yield per unit area. The best combination was treatment 9 (T9 = B, 1 g/L; Mo, 0.08 g/L; Cu, 0.05 g/L), and resulted in a 35.1% increase in yield per unit area compared with the control group (T1). Although the optimal combined application of microfertilizers did not change the bimodal trend of diurnal variation of photosynthesis, it effectively increased the daily average, peak, and valley values of the photosynthetic rate by alleviating the nonstomatal limitation and the photosynthetic midday depression. Pseudostellaria heterophylla leaves showed greater photochemical activity and less photoinhibition of photosystem II in T9. Major effects were that it helped protect the activity of the oxygen-evolving complex to reduce the oxidative damage of chloroplasts and prevent the dissociation of thylakoid. The microfertilizer application also enhanced the electron receiving ability of the QB and plastoquinone (PQ) electronic pools, thereby increasing the ability of electron transfer from QA to QB. The number of reaction centers per unit area was promoted notably by the fertilization treatment.

Er:Yag Laser Root Modification for Single Root Recession Class III Coverage – Case Report

Gingival recession is a common dental condition causing esthetic and functional problems to the patients. In the present case report gingival recession Miller class III is treated with bilaminar technique and subepithelial connective tissue graft where the tooth root surface is modified by Er:YAG laser and the case is observed for 5 months. There were no complications or side effects during the surgery and the healing period. The patient was stable after 5 months of follow-up. It could be concluded that the Er:YAG laser could be used in addition to mucogingival surgery, but longer observation and more studies are needed to clarify and prove its adjunctive application.

Comparing the effect of Reciproc R25 rotary file system on the amount of apical extrusion of debris via using it with different reciprocal angles

Aim: To compare the amount of apically extruded debris using Reciproc (R25) file with different reciprocal angles. Methodology: In this research, 60 extracted mandibular premolars with a single root, a single canal, and a single apical foramen were used. Specimens, the working length of which was determined by a stainless steel 10-K file, were randomly distributed into three experimental groups (n = 20) as follows: Group 1 150° counterclockwise (CCW)-30° clockwise (CW); Group 2 180° CCW-60° CW; and Group 3 210° CCW-90° CW. For the irrigation, 10 mL of distilled water was administered via syringe pump. The extruded debris was collected into Eppendorf tubes tared in advance. The distribution of data was analyzed using a Shapiro-Wilk test. A Kruskal-Wallis H test was used for statistical analysis. The null hypothesis is no significant difference between the groups in terms of the amount of apical extrusion of debris. Results: There was no statistically significant difference between the groups with regard to amount of apical extrusion of debris (p>0.05). Nevertheless, the highest average amount of extrusion of debris was detected in group 1, and the lowest in group 3. Conclusion: According to the results of this study, different reciprocal angles during chemomechanical preparation has no significant effect on the amount of apical extrusion of debris. How to cite this article: Çelik N, Kaya S, Adıgüzel Ö. Comparing the effect of Reciproc R25 rotary file system on the amount of apical extrusion of debris via using it with different reciprocal angles. Int Dent Res 2021;11(Suppl.1):63-6. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.10 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Results of testing potato hybrids in breeding nurseries in the Komi Republic

Relevance. Potato hybrids obtained when creating varieties adapted to the weather conditions of the Komi Republic must have maximum resistance to constantly changing environmental conditions while maintaining the yield indicator at a high level. In addition, breeders impose requirements for their high field resistance to the main diseases common in the region: late blight, alternaria, rhizoctonia, scab and viruses (X, Y). In 2020, in the course of a continuously operating selection process, produced on the basis of the Institute of Agrobiotechnology FRC Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences (Syktyvkar) together with the FRC potato named after A.G. Lorkh (Korenevo), samples were taken from the nursery of the main test of hybrids.Methods. The studies were carried out on five hybrids sent from the FRC of Potato named after A.G. Lorkh obtained by hybridization of the original parental forms, growing hybrid seedlings and single-root hybrids, followed by selection in nurseries of single-root hybrids, second-year hybrids, preliminary and main tests already directly at the Institute of Agrobiotechnology FRC of the Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences. Observations, counts and culling in each nursery were carried out in accordance with the methodological recommendations on the technology of the potato breeding process. According to the research results, the hybrids were assessed in terms of yield, yield range (the difference between the maximum and minimum values for the study period), realization of yield potential (the ratio of the average yield to the maximum over the years of research) and coefficient of variation, as well as disease resistance.Results. As a result of a comprehensive assessment of potato samples in the nursery of the main test, three promising hybrids were identified — 1992–14, 2000–60 and 2139– 5 with an average yield at the level of standard varieties and higher (23.6–31.2t/ha), having a high stability and disease resistance.