Effect of different surface treatments on bond strength between zirconia posts and root surfaces

Aim: In recent years, especially with the increase in aesthetic demands, there has been a requirement to use the best aesthetic materials for dental restorations. These restorations are especially needed in those teeth that have crown loss due to a tooth fracture or extreme anterior tooth decay, post-core treatment has been applied as getting support by tooth roots. the aesthetic disadvantages and making use of the strength resistance of various metals. In this case, zirconium, which is a white‑coloured metal, is preferred. In this study, zirconia posts with different surface treatments were cemented to the root canal and bond strength was then evaluated. Materials and Methods: Forty mandibular second premolar teeth were used in this study. Crowns of all teeth were removed to 14 mm from the enamel-cement margin by separation under irrigation. Root canals were cleaned, shaped and filled. Teeth were kept in distilled water while zirconia posts were prepared. Zirconia posts were divided into four groups according to the surface treatment methods as follows: a control group, a CoJet applied group, a sandblasting+laser group and an Er:YAG laser group. The Er:YAG laser was administered at 450 mJ at 10 Hz for 60 seconds with a 100-μs pulse duration. Surface-treated posts were bonded to the root canal with Panavia F cement. Cores were made with the standardized strip crowns. 5000 cycles, 5-55 °C thermal cycle applied with transition time at 5 seconds. For push-out tests, roots were embedded in translucent acrylic resin and coronal, middle third and apical sections were cut into 1.5-mm slices. The maximum load at failure was recorded for each specimen in newtons and then converted into megapascals (MPa). Each specimen was inspected with a scanning electron microscope (SEM) at a magnification of 100 X. Data were analysed using Games‑Howell tests with a significance level of 0.05. Results: The coronal section from Group 3 had the highest mean push-out bond strength (18.01 MPa), while the apical section from Group 1 had the lowest (4.49 MPa). Surface treatments had no significant effect on the mean push-out bond strengths of zirconia posts (p > 0.05). However, dividing the root canal into three sections had a significant effect on bond strength (p < 0.05). When the results were evaluated for all groups, the push-out bond strength was highest in the coronal section, then in the middle third and the lowest in the apical section. How to cite this article: Dündar Yılmaz B, İzgi AD. Effect of different surface treatments on bond strength between zirconia posts and root surfaces. Int Dent Res 2020;10(2):49-54. https://doi.org/10.5577/intdentres.2020.vol10.no2.4 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Early diagnosis of Cantrell’s Pentalogy in a newborn baby

A clinical case of early diagnosis of Pentalogy of Cantrell (POC) in a newborn infant is presented. The features of the formation of the defect and its classification are described. A crucial role in verifying the diagnosis was performed by CT scan with intravenous contrast, which revealed a narrowing of the pulmonary artery trunk; located subcutaneously above the umbilical ring, the diverticulum of the left ventricle of the heart, originating from the apical section of the left ventricle and connected to its cavity by a linear isthmus located along the middle line, as well as a local defect of the diaphragm in the anterior section. Taking into account the accumulated experience, it is generally recognized that when establishing this diagnosis in the first trimester, termination of pregnancy is more preferable. Therefore, parents should be notified of a possible adverse outcome in a timely manner. The presented observation reflects the high importance of early diagnosis of congenital forms of combined pathology in children, requiring the use of modern research methods to determine the tactics and conduct timely effective treatment.

Quantificação de açúcares totais e auxina no desenvolvimento inicial de mini-toletes de cana-de-açúcar

Reserve carbohydrate and auxinspresent in the stalk are involved in the development of sugarcane plant. Thus, this study aimed to quantify total sugarsand auxin of type indoleacetic acid (IAA) content in the initial development of stalks and sugarcane buds, as a function of diameter and position in the stalk. The experiment was conducted in a 3x3 factorial scheme (diameter x stalk section), with four replicates. Eleven-month-old plants stalks were classified into three diameters (fine < 2 cm; medium 2-3 cm; thick > 3 cm) and divided into three sections (apex, middle and base). Data were submitted to analysis of variance, and when significant the means were compared by the Tukey (p≤0.05). The diameter factor resulted in greater interference in the content of the biochemical variables evaluated (sugars and auxin), in comparation to stalk section. Biometric variables (length and dry mass of shoot and roots, budding and budding speed index), in general, were mostly affected by stalk section factor. The diameter factor interfered in the content of endogenous auxin in the stalk and buds. Root growth was related to endogenous auxin concentration and the highest sprouting percentage was obtained from the apical section of the talk due to the availability of reducing sugars content.The use of mini-stalks for the propagation of sugarcane proved feasible.Keyword:apical dominance;plant hormone; propagation;Saccharum spp.

STRIOCADULUS MAGDALENENSIS, A NEW DEEP-SEA SCAPHOPOD (MOLLUSCA: SCAPHOPODA: GADILIDAE) FROM THE COLOMBIAN CARIBBEAN

We describe a new bathyal species of scaphopod belonging to the genus Striocadulus Emerson based on conchological and radular characters. The specimens were collected at a depth of 404-412 m off Bocas de Ceniza (Colombian Caribbean). Striocadulus magdalenensis new species can be distinguished from its other congeners by differences in its apical section, and both number and extent of longitudinal striae. This is the rst record of this genus in the Atlantic Ocean.

Micro-CT analysis of the Caribbean octocoral Eunicea flexuosa subjected to elevated pCO2

Rising anthropogenic carbon dioxide has resulted in a drop in ocean pH, a phenomenon known as ocean acidification (OA). These acidified waters have many ramifications for diverse marine biota, especially those species which precipitate calcium carbonate skeletons. The permanence of coral reef ecosystems is therefore closely related to OA stress as habitat-forming corals will exhibit reduced calcification and growth. Relatively little is known concerning the fate of other constituent taxa which may either suffer concomitant declines or be competitively favoured in acidified waters. Here, we experimentally (49 d) test the effects of next century predictions for OA (pH = 7.75, pCO2 = 1081 µatm) vs. near-present-day conditions (pH = 8.01, pCO2 = 498 µatm) on the common Caribbean octocoral Eunicea flexuosa. We measure linear extension of this octocoral and use a novel technique, high-resolution micro-computed tomography, to measure potential differences in the morphology of calcified internal skeletal structures (sclerites) in a 2 mm apical section of each branch. Despite the use of highly accurate procedures, we found no significant differences between treatments in either the growth of E. flexuosa branches or the structure of their sclerites. Our results suggest a degree of resilience to OA stress and provide evidence that this octocoral species may persist on Caribbean coral reefs, despite global change.

A Comparative Study of the Removal of Smear Layer by Two Endodontic Irrigants and Nd:YAG Laser: A Scanning Electron Microscopic Study

The aim of this study was to compare the effect of 17% EDTA, 5% maleic acid, and Nd:YAG laser on smear layer removal by SEM. Eighty single-rooted teeth were divided into three groups of 25 according to the final procedure for smear layer removal: irrigation by 17% EDTA or 5% maleic acid or Nd:YAG laser irradiation. The other five teeth was used as control. Roots were sectioned into buccal and lingual parts, and smear layer presence was recorded in the coronal, middle, and apical thirds under SEM. Data were analyzed by Kruskal-Wallis, Mann-Whitney, Friedman, and Wilcoxon tests. There was no significant difference between smear layer removal of 17% EDTA and 5% maleic acid. Nd:YAG laser showed the least effect significantly. The coronal part of samples was significantly cleaner than the middle, and the middle was cleaner than the apical section. 17% EDTA and 5% maleic acid were more effective in smear layer removal compared to Nd:YAG laser.

Characteristics of Sugar Content in Different Sections and Harvest Maturity of Bamboo Shoots

Bamboo shoots (Phyllostachys pubescens Mazel) harvested from two cultivation areas were used to investigate the amount of accumulated sugars (sucrose, glucose, and fructose) in four sections along the length of a bamboo shoot. Bamboo shoots harvested from above ground (emerged bamboo shoot) and underground of the same cultivation area were also used to study the changes in sugar content during storage at both 5 and 25 °C. The amounts of sucrose, glucose, fructose, and total sugar of underground bamboo shoots were higher than those of emerged shoots. Sucrose content in the apical section was significantly higher than that in other sections. Meanwhile, higher amounts of glucose, fructose, and total sugar (the sum of sucrose, glucose, and fructose) were observed in the basal section. Changes in sugar content were also observed during storage. The fresh, unpeeled bamboo shoots have particular cellular chemical properties and respond differently to storage duration and condition depending on harvest maturity.

173 Calorimetric Evaluation of Metabolic Intensity of Apple Lateral Buds and Roots during the Transition from Para- to Endodormancy

Potted 1-year-old `Starking Spur' and `Golden Delicious' trees on MM.106 were used to characterize the metabolic changes in lateral buds and rrots during their transition from para- to endodormancy. Sampling period was from 4 Sept. to 25 Nov. 1999 at 10-day intervals. Well-formed lateral buds were collected from the apical section of current growth; while root samples were white rootlets. Isothermal calorimetry at 25 °C was used to evaluated metabolic activity (q), respiration rate (RCO2), metabolic efficiency (q/RCO2), and growth rate (RSG·ΔHB). In both cultivars, q from buds showed significant differences (P ≤ 0.05) among sampling dates; `Starking' rose from 1.8 to 3.7 μW/mg dry weight (dw), while in `Golden' change was from 2.1 to 3.3 μW/mg dw. RCO2, q/RCO2, and RSG·ΔHB showed a pattern similar to q. On each sampling date, cuttings were also forced to break and, in all dates, buds broke after 21 days, demonstrating a paradormant condition. MM.106 root tips q behave differently depending on the variety they were grafted on to. When grafted with `Starking', root tips produced a small, but significant, increase in q (from 9.1 to 15.7 μW/mg dw) as the season progressed. RCO2 and RSG·ΔHB behaved similarly, increasing from 27.6 to 57.6 mmol CO2/mg dw and 3.4 to 8.3 μW/mg dw, respectively. These conditions agreed with a dynamic root growth. A small decrease in q/RCO2 was observed. However, when grafted with `Golden' root tips metabolic responses did not increase; furthermore, q decreased while RCO2, q/RCO2, and RSG·ΔHB did not show a defined pattern. Four complete 2-year-old trees of each variety, kept in 1-m3 containers, were sampled. The relation of root/wood dry matter was estimated, with difference found between varieties.