scholarly journals Evaluation of Sealing Materials Adhesion to Enamel An in vitro study

2017 ◽  
Vol 54 (1) ◽  
pp. 129-132
Author(s):  
Andreea Simona Pop ◽  
Radu Septimiu Campian ◽  
Mariana Pacurar ◽  
Elina Teodorescu ◽  
Olimpia Bunta ◽  
...  

Sealing the pits and fissures of posterior teeth represents a local and specific method of caries prevention. The aim of this study was to evaluate the adhesion of two materials used in sealing pits and fissures: Pitt and Fisure and Fissurit FX (Voco), with the help of the scanning electronic microscope (SEM). The results of the study revealed a much higher quality of the Fissurit FX (Voco) product both in terms of adhesion to the enamel and material homogeneity. The Pitt and Fisure product showed a high degree of detachment from the enamel, marginal infiltration, large particles and a high concentration of inorganic particles.

2022 ◽  
pp. 1-9
Author(s):  
Hiroshi Nozaki ◽  
Yoshihiro Tange ◽  
Yoji Inada ◽  
Takashi Uchino ◽  
Nakanobu Azuma

<b><i>Introduction:</i></b> Ultrapurification of dialysis fluid has enabled highly efficient dialysis treatments. Online hemodiafiltration is one such treatment that uses a purified dialysis fluid as a supplemental fluid. In this method, an endotoxin retentive filter (ETRF) is used in the final step of dialysis fluid purification, with the aim of preventing leakage of endotoxins. Sodium hypochlorite and peracetic acid are used as disinfecting agents for the dialysis fluid pipes containing the ETRF; however, the effects of these agents on ETRF membrane pores have not been fully clarified. <b><i>Methods:</i></b> Water permeability (flux) and endotoxin permeability were assessed in 3 types of ETRFs made with different membrane materials: polyester polymer alloy (PEPA), polyether sulfone (PES), and polysulfone (PS). High-concentration sodium hypochlorite and 2 types of peracetic acid were used as disinfecting agents, and the changes in flux and the endotoxin sieving coefficient (SC) were measured. <b><i>Results:</i></b> After repeated use of high concentrations of sodium hypochlorite and peracetic acid, the PEPA and PES ETRFs did not permit passage of endotoxins, regardless of their flux. However, in the PS ETRF, the flux and endotoxin SC increased with the number of cleaning cycles. No differences were observed according to the concentration of peracetic acid disinfecting agents. <b><i>Conclusion:</i></b> PEPA and PES ETRFs completely prevent endotoxin leakage and can be disinfected at concentrations higher than the conventionally recommended concentration without affecting pore expansion. Even new PS ETRFs have low levels of endotoxin leakage, which increase after disinfection cycles using sodium hypochlorite and peracetic acid.


2015 ◽  
Vol 5 (1) ◽  
pp. 22-26
Author(s):  
Muzin Shahi Shaik ◽  
Snigdha Pattanaik ◽  
Sudhakar Pathuri ◽  
Arunachalam Sivakumar

Introduction: Bond strength is an important property and determines the amount of force delivered and treatment duration in orthodontics. Many light-cured bonding materials are being used; but it is required to determine the most efficient one withdesired bond strength. Objective: To determine and compare the shear bond strength of three visible light-cured composites (Transbond XT, Heliositand Enlight) and two self-cured composites (Rely-a-bond and Concise). Materials & Method: 100 extracted premolars were collected and randomly divided into 5 test groups of different adhesives. Brackets were bonded to the teeth in each test group with the respective adhesive according to the manufacturer’s instructions. Each specimen was debonded using Universal Testing Machine and the shear bond strength for each specimen was calculated. All the groups were compared by ANOVA one-way test. Results: There were statistically significant differences among the five groups (P<0.05). The shear bond strength of Enlight (13.92 ± 3.92) is similar to Transbond XT (14.30 ± 4.35). Conclusion: Light cure composites showed higher bond strength than self cure composites.


2005 ◽  
Vol 13 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Ana Cristina Gerent Petry Nunes ◽  
Maria José de Carvalho Rocha

The purpose of this research was to evaluate the diffusion of calcium (Ca+2) and hydroxyl (OH-) ions from materials with a calcium hydroxide base - Ca(OH)2 through the intact roots of deciduous teeth. This diffusion of ions is important for periapical healing. Forty-six deciduous teeth were selected and instrumented to their working length with #40 files. The teeth were washed during cleaning and shaping with a 1% sodium hypochlorite (NaOCl) solution. The canals were dried with paper points. The teeth were divided into 4 groups based on the sealer type, with 10 specimens in each group. A fifth group of 6 teeth without sealer constituted the control group. The materials used as sealers were: Ca(OH)2 paste associated to propylene glycol (CaPE) thickened at the proportion of 2:1 w/v; UFSC (Federal University of Santa Catarina) paste - a mixture of 0.3g of zinc oxide with 0.3g of Ca(OH)2 with 0.2ml of olive oil 1:1 w/w; Vitapex® and Sealapex®. The coronal access was sealed with a glass ionomer after the root had been filled with each sealer. A one-third apical surface and foramen was hard-pressed with Araldite®. The teeth were stored individually in flasks containing saline solution at 37ºC and 100% humidity. The OH- and Ca+2 ions diffusion levels were determined using a pH meter and an atomic absorption spectrometer. Data were collected at 48 hours and at intervals of 7, 30, 45 and 60 days. Statistical analysis was performed using ANOVA to compare groups. In the pH evaluation, the CaPE group presented the largest OH- ions diffusion, which peaked at sixty days (p=0.0309), when compared to the other groups (p<0.0001). In relation to amount of Ca+2 ions released, the CaPE paste showed the best results, followed by the UFSC's paste. These results suggest that the CaPE paste was the material that allowed the highest diffusion of OH- and Ca+2 ions.


1997 ◽  
Vol 41 (2) ◽  
pp. 335-346 ◽  
Author(s):  
Naoyuki Matsumoto ◽  
Fumiaki Kawano ◽  
Kan Nagao ◽  
Nozomu Tada

2020 ◽  
Vol 45 (1) ◽  
pp. 62-70
Author(s):  
C Dettwiler ◽  
F Eggmann ◽  
L Matthisson ◽  
C Meller ◽  
R Weiger ◽  
...  

SUMMARY Aim: The aim of this study was to quantitatively compare conventional composite removal and composite removal supported by the fluorescence-aided identification technique (FIT) regarding the completeness, selectivity, and duration of the procedure in directly restored permanent posterior teeth. Methods and Materials: Two operators removed standardized direct class II composite restorations (n=32 per operator) in human tooth models under simulated clinical conditions. According to a randomized allocation scheme, removal was performed with either the conventional technique (contra-angle handpiece) or supported by FIT. The duration of each removal procedure was recorded. The completeness and selectivity were volumetrically assessed through superimposition of three-dimensional surface scans. Statistical significance was tested by examining the overlap of 95% confidence intervals (CI). Multiple comparison was performed with Tukey tests for each variable. Results: Compared with the conventional technique, composite removal with FIT was faster (329 seconds [95% confidence interval (CI): 268-390 seconds] vs 179 seconds [95% CI: 150-208 seconds]), generated less tooth substance loss (4.53 mm3 [95% CI: 3.77-5.30 mm3] vs 2.77 mm3 [95% CI: 2.11-3.43 mm3]), and left behind less composite residue (1.58 mm3 [95% CI: 1.23-1.94 mm3] vs 0.53 mm3 [95% CI: 0.39-0.67 mm3]). Conclusion: Within the limitations of this in vitro study, FIT facilitated the selective and expeditious removal of tooth-colored composites in directly restored posterior teeth.


Nutrients ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 53
Author(s):  
Narjes Nasiri Ansari ◽  
Flora Spentza ◽  
Georgios Dimitriadis ◽  
Aphrodite Daskalopoulou ◽  
Angeliki Karapanagioti ◽  
...  

Orexin-A is a peptide hormone that plays a crucial role in feeding regulation and energy homeostasis. Diurnal intermittent fasting (DIF) has been found to increase orexin-A plasma levels during fasting hours, while Ramadan fasting which resembles DIF, has led to beneficial effects on endothelial function. Herein, we aimed to investigate the effects of orexin-A on the expression of molecules involved in the atherogenesis process: Monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases 2 and 9 (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinase-1 and 2 (TIMP-1 and TIMP-2), in human aortic endothelial cells (HAECs). HAECs were incubated with orexin-A at concentrations of 40 ng/mL, 200 ng/mL and 400 ng/mL for 6, 12 and 24 h. The mRNA levels of MCP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 and orexin-1 receptor were measured by real-time qPCR. We also evaluated the MMP-2, p38, phospho-p38, NF-κΒ/p65 as well as TIMP-1 protein levels by Western blot and ELISA, respectively. MMP-2 activity was measured by gelatin zymography. Short-term 6-h incubation of HAECs with orexin-A at a high concentration (400 ng/mL) decreased MCP-1, MMP-2 expression, MMP-2/TIMP-1 ratio (p < 0.05), and MMP-2 activity, while incubation for 24 h increased MCP-1, MMP-2 expression (p < 0.05), MMP-2/TIMP-1 and MMP-2/TIMP-2 ratio (p < 0.01 and p < 0.05, respectively) as well as MMP-2 activity. The dual effects of orexin-A are mediated, at least in part, via regulation of p38 and NF-κΒ pathway. Orexin-A may have an equivocal role in atherosclerosis process with its effects depending on the duration of exposure.


2020 ◽  
Vol 18 (3) ◽  
pp. 519-527
Author(s):  
Tamires Borges de Lima ◽  
José Guilherme Neves ◽  
Ana Paula Terossi de Godoi ◽  
Ana Rosa Costa ◽  
Viviane Veroni Degan ◽  
...  

2017 ◽  
Vol 1 ◽  
Author(s):  
Azah Binti Zainal Abidin ◽  
Azmiera Binti A. Rahman ◽  
Kyaw Mya Htun ◽  
Tin Maw

<p class="AbstractContent"><strong>Objective</strong>: The purpose of this study was to evaluate and compare the dissolving effect of chloroform on AH 26 (resin-based root canal sealer), Endofill (zinc oxide eugenol-based root canal sealer) and Sealapax (calcium hydroxide-based root canal sealer). Many previous literatures have compared the solubility of several solvents towards gutta percha but very few on endodontic sealers.</p><p class="AbstractContent"><strong>Methods</strong>: The materials used in this experiment apart from the three endodontic sealers are 30 standardized stainless-steel rings, microscopic glass slide, chloroform, acetone, and three decimal digital weighing scales. Thirty standardized stainless steel rings 8mm in diameter and 3mm in height were used for the preparation of sealer specimens and were randomly divided into three experimental groups of ten rings each. Each sealer was then mixed in accordance with the manufacturer’s instructions and introduced into the stainless-steel rings and was weighed to obtain the initial weight. Each sealer was weighed again after immersion in chloroform. The amount of sealer lost was the difference between this measurement and the original weight of the sealer. The results were tabulated and analyzed using analysis of variance (ANOVA).</p><p class="AbstractContent"><strong>Results</strong>: The ANOVA test showed that there were significant differences existed between the groups. The post-hoc (Bonferroni) test showed that AH26 had significantly greater dissolution than Sealapex. However, there were no significant differences in dissolution between AH26 vs. Endofill and Sealapex vs. Endofill.</p><p class="AbstractContent"><strong>Conclusion:</strong> According to the methodology proposed and based on the results of this study, it may be concluded that AH26 presented the highest dissolution value.</p>


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7664
Author(s):  
Josipa Vukelja ◽  
Eva Klarić Sever ◽  
Ivan Sever ◽  
Silvana Jukić Krmek ◽  
Zrinka Tarle

The aim of this in vitro study was to assess the effect of two different adhesive application methods on shear dentin bond strength (ISO 29022) using three various adhesive systems. A mid-coronal section of 77 intact third human molars with fully developed apices was made to create flat bonding substrates. The materials used in the study were Excite F (Ivoclar Vivadent), Prime&Bond Universal (Dentsply Sirona) and G-Premio Bond (GC). The application of each adhesion system was performed in two different ways. In the first group, the bonding agent was light cured immediately after the application (conventional method), while in the second group the adhesive and composite were cured concurrently (“co-curing” method). A total of 180 specimens were prepared (3 adhesives × 2 method of application × 30 specimens per experimental group), stored at 37 °C in distilled water and fractured in shear mode after 1 week. Statistical analysis was performed using ANOVA and Weibull statistics. The highest bond strength was obtained for Prime&Bond conventional (21.7 MPa), whilst the lowest bond strength was observed when co-curing was used (particularly, Excite F 12.2 MPa). The results showed a significant difference between conventional and co-curing methods in all materials. According to reliability analysis, the co-curing method diminished bond reliability. Different application techniques exhibit different bond strengths to dentin.


Sign in / Sign up

Export Citation Format

Share Document