scholarly journals Consequences of chemical residue formation during potentiation of final irrigation

2020 ◽  
Vol 19 ◽  
pp. e209594
Author(s):  
Mirela Cesar Barros ◽  
Jessica de Almeida Coelho ◽  
Lidiane de Castro Pinto ◽  
Marco Antônio Húngaro Duarte ◽  
Flaviana Bombarda de Andrade

Seeking to increase the efficiency of endodontic irrigation, the association of different solutions as final irrigant has been investigated, such as sodium hypochlorite with chlorhexidine. The literature shows that the combination of these substances leads to the formation of a brownish precipitate, but does not reveal measurements of the intensity of this precipitate and its consequences. Aim: The present study aimed to evaluate the change in dentin color and the obliteration of the dentinal tubules after the association of sodium hypochlorite (NaOCl) with chlorhexidine (CHX) in the final irrigation. Methods: Fifty sterile human lower premolars were prepared with a ProDesign R 35.05 files and divided into 6 groups. Four different NaOCl concentrations (0.5%; 1%, 2.5% and 5.25%) associated with 2% CHX were tested, in addition to 2 control groups, using only 2.5% NaOCl and 2% CHX, respectively. After the final irrigation protocol, the dentin color change was evaluated by spectrophotometry immediately and after 24 hours, and the dentinal tubule obliteration was assessed by scanning electron microscopy. Results: It was possible to verify that regardless the NaOCl concentration used when associated with CHX, a chemical residue was formed, with consequent dentin pigmentation and tubular obstruction. There was a trend towards increased dentin pigmentation and tubular obstruction due to the deposition of the chemical residue formed by this association. Conclusion: It can be concluded that all concentrations of NaOCl associated with CHX caused color changes and tubular obstruction, being proportional to the concentration of NaOCl used.

2018 ◽  
Vol 12 (03) ◽  
pp. 398-402
Author(s):  
Kanav Jain ◽  
Padmanidhi Agarwal ◽  
Supriya Jain ◽  
Mukut Seal ◽  
Twisha Adlakha

ABSTRACT Objective: The objective of this study was to chemically evaluate precipitate formation on irrigation by different concentrations of chlorhexidine (CHX) and alexidine (ALX) with sodium hypochlorite (NaOCl). Materials and Methods: Six test tubes were prepared with 1 ml of 4% NaOCl. One milliliter of 2%, 1%, 0.5%, and 0.25% ALX was added to the first four, and in the last two, 1 ml of 2% CHX and 0.2% CHX was added, respectively. Samples were observed for color changes or precipitates at multiple time intervals. All solutions were then centrifuged at 1000 rpm for 10 min and re-examined for precipitates. This process was repeated twice. Fifty freshly extracted premolars were biomechanically prepared, dried, divided into two groups, and irrigated with 10 ml of 4% NaOCl and 10 ml of 2% ALX (Group 1) and 10 ml of 4% NaOCl and 10 ml of 2% CHX (Group 2). These samples were sectioned and observed for precipitates on the dentinal surfaces by scanning electron microscopy (SEM). Results: The color of the solution of ALX and NaOCl stayed transparent and no precipitate was observed. A color change was noted immediately on mixing CHX and NaOCl which did not change with time. Precipitates were only observed in the solutions of CHX with NaOCl and after centrifuging them. SEM views also showed dense precipitates covering the dentinal surface and occluding the dentinal tubules in Group 2. Conclusion: The interaction of ALX and NaOCl does not produce precipitates which together with its better antimicrobial action make ALX a more effective and safer replacement for CHX as an adjunctive endodontic irrigant.


2020 ◽  
Vol 10 (18) ◽  
pp. 6513
Author(s):  
Emilia Bologa ◽  
Simona Stoleriu ◽  
Gianina Iovan ◽  
Cristina Angela Ghiorghe ◽  
Irina Nica ◽  
...  

This in vitro study evaluated the effects of dentifrices containing nano-hydroxyapatite (n-HAp) on dentinal tubule occlusion and on mineral deposition. Dentin specimens of ten human teeth were submersed for 30 s in 40% citric acid and then randomly divided into four groups (three study groups and one control group). In the study groups, the dentin samples were exposed to three different n-HAp toothpastes: Karex (Dr. Kurt Wolff GmbH & Co. KG, Bielefeld, Germany), Biorepair Plus Sensitive (Coswell SpA, Bologna, Italy), and Dr. Wolff’s Biorepair (Dr. Kurt Wolff GmbH & Co. KG, Bielefeld, Germany); in the control group no toothpaste was applied. All of the samples were evaluated using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. In the control group all of the samples showed a frank and wide opening of the dentinal tubules, whereas in the study groups different degrees of tubule closure by mineral depositions were observed. Toothpastes containing n-HAp determined a significant occlusion of dentinal tubules and a significant increase of mineral deposition on the dentin surface. All three tested toothpastes showed similar results regarding the degree of dentinal tubule closure. Varying degrees of differences in calcium, phosphate, carbon, and oxygen ion concentrations among the three tested toothpastes were obtained.


Author(s):  
Vincia Valencio D'souza ◽  
Rushikesh Ramesh Mahaparale ◽  
Tiptur Manjunath Mangala ◽  
Adish Anand Saraf ◽  
Sneha Ramling Mali ◽  
...  

Introduction: When sealer is adapted well to the root canal wall, there is less tendency for microleakage and strength of root canal is enhanced. Therefore, it is important for the sealer to possess good tubular penetration depth and adaptation to dentinal walls. Aim: To compare the effects of sonic activation of 5.25% Sodium Hypochlorite (NaOCl) and incorporation of Zinc Oxide (ZnO) nanoparticles in AH Plus sealer on tubular sealer penetration. Materials and Methods: Forty extracted human mandibular premolars with a single root canal were used for this invitro study from October 2019 to January 2020. All teeth were prepared upto F3 with Pro Taper Universal rotary system. Teeth were randomly divided into four groups of 10 teeth each. Group I (control) included teeth obturated using AH plus sealer, Group II: teeth obturated using AH plus sealer incorporated with ZnO nanoparticles, Group III: teeth prepared along with sonic activation of the irrigant followed by obturation using AH plus sealer and Group IV: teeth prepared along with sonic activation of the irrigants followed by obturation with AH plus sealer incorporated with ZnO nanoparticles. Irrigation was achieved with 5.25% sodium hypochlorite. The canals were dried and obturated using respective sealers and single gutta percha cones. After storage at 37°C and 100% humidity, the roots were split into two halves and sealer penetration in the dentinal tubules was examined by using scanning electron microscope. The values obtained were statistically analysed using One-way Analysis of Variance (ANOVA) with significant p-value less than 0.05. Results: In all the groups, sealer penetrated into the dentinal tubules. There was enhanced tubular sealer penetration (289.57±59.43 μm) after sonic activation of the irrigant (group 3) followed by that on addition of ZnO nanoparticles to the sealers (group 2) (278.21±71.24 μm) and the least was seen in the control group (group 1) (211.5±66.33 μm). The combined effect of both i.e., use of sonic activation of irrigant followed by obturation using modified sealer with gutta percha (group 4) (318.64±88.27 μm) showed greatest tubular sealer penetration depth. Conclusion: Incorporation of nanoparticles aids in improving sealer penetration which is further enhanced in case of sonic activation during irrigation.


2012 ◽  
Vol 37 (4) ◽  
pp. 340-355 ◽  
Author(s):  
LMS Al-Saud ◽  
HNA Al-Nahedh

SUMMARY Objectives This in vitro study aimed to microscopically evaluate and compare the occluding effect of the Nd:YAG laser and different dentin desensitizing agents on human dentinal tubules. Materials and Methods The Nd:YAG laser (SunLase™ 800) and four commercially available and professionally applied dentin desensitizers (Gluma® desensitizer, Tenure Quick®, Quell™ desensitizer, and VivaSens®) were investigated in this study. Sixty-four extracted intact human molars were used. Each dentin surface was divided by shallow indentation into two halves, one of which was used for treatment and the other of which served as a control. The dentin surfaces were etched to remove any smear plugs and to mimic the open dentinal tubules of sensitive dentin using 0.5 M ethylenediaminetetraacetic acid (pH 7.4) for two minutes (applied with a microbrush) and then rinsed with an air-water syringe for 30 seconds. The laser samples (n=16) were randomly divided into four groups of four samples each. These groups were the step-up technique group, the 14-day group, the one-minute group, and the two-minute group. Forty-eight samples were treated with the four tested desensitizing agents and were randomly divided into four groups (n=12/group). Each group was further subdivided into three subgroups (n=4). Samples of the first subgroup were treated for 14 days, while those of the second subgroup were treated once. Samples of the last subgroup were fractured longitudinally after a single treatment. All of the samples were then examined under a scanning electron microscope. Results The Nd:YAG laser–irradiated dentin showed reduction or complete obliteration of the dentinal tubule lumen; thus, the treatment modified the original dentinal structure. The lased dentin surface in the two-minute group showed bubble-like changes in the area of the dentinal tubules' orifices. Statistically, the two-minute group was found to have a significantly higher percentage of partially or fully occluded tubules than did the one-minute group. All of the studied desensitizing agents produced occlusion of the dentinal tubules; however, the appearance of the precipitates, the level of coverage, and the degree of dentinal occlusion varied among the tested products. Conclusion Throughout the specified period of this study, occlusion and/or narrowing of the open dentinal tubules have been successfully achieved with both treatment approaches.


2020 ◽  
Vol 11 (3) ◽  
pp. 268-273
Author(s):  
Zahra Khoubrouypak ◽  
Masoumeh Hasani Tabatabaei ◽  
Nasim Chiniforush ◽  
Zohreh Moradi

Introduction: Tooth hypersensitivity is among the most common patient complaints caused by the response of exposed dentin to external stimuli. No definite treatment has been suggested so far for dentin hypersensitivity (DH). This study aimed to compare the efficacy of the diode laser alone and in combination with Gluma and chromophore in occluding opened dentine tubules and the treatment of DH. Methods: This in vitro study was conducted on 30 extracted human third molars kept in 0.1% thymol solution. The teeth were mounted in transparent acrylic resin and the buccal enamel was cut to expose the outer third of dentin. The samples were then divided into 6 groups of negative control (no smear layer removal), positive control (smear layer removal with 6% citric acid application), 810 nm diode laser irradiation (energy density 55.55 J/cm2 , 1 W for 20 seconds in a continuous mode), chromophore (1 mg/mL indocyanine green, ICG) plus diode laser irradiation (1 W, 20 seconds), Gluma plus diode laser irradiation, and Gluma + chromophore + diode laser. Dentinal tubules were evaluated under a scanning electron microscope at x2000 magnification. The mean percentage of the obstruction of dentinal tubules was reported as mean and standard deviation. Considering the normal distribution of the data, two-way ANOVA was applied to compare the efficacy of treatments, and an independent-samples t test was used for pairwise comparisons at P<0.05 level of significance. Results: The highest mean percentage of the obstruction of dentinal tubules was noted in the diode laser/chromophore/Gluma group (65.68±12.31%) while the lowest value was noted in the diode laser/Gluma group (24.33±5.90%). Pairwise comparisons revealed significant differences between all groups (P<0.05) except for the difference between the laser/Gluma/chromophore and laser/ chromophore groups (P=0.20). Conclusion: It seems that chromophore increases the efficacy of the diode laser for the obstruction of dentinal tubules.


2020 ◽  
Vol 5 (1) ◽  
pp. 20-23
Author(s):  
Mai H. Abdelrahman ◽  
◽  
Mohamed Y Hassan ◽  

Background: Despite improvements and advances in materials and methods, root canal treatment is not always satisfactory. After completing the obturation procedures, retreatment might be mandatory in cases of reinfection or inappropriately cleaned root canal. Retreatment strategy involves elimination of the obturating material, and then the whole mechanical and filling procedures are repeated again. Thus, root canal sealers removal shouldn’t represent an obstacle. Objective: The current study aimed is to investigate and observe the cleanliness of root canal walls that were previously obturated with two types of calcium silicate bioceramic sealers compared to a resin sealer. Materials and Methods: 21 single-rooted premolars were utilized. After complete removal of the obturating materials using Protaper retreatment universal system, the roots were cut by the use of a hammer and a chisel, then the middle third of the retreated canals were observed under a scanning electron microscope at magnification 1000x, the amount of clear, opened dentinal tubules was compared. Results: Among the three investigated sealers, ADSEAL showed the largest number of clear dentinal tubules while, a fewer open dentinal tubule were observed with Well Root and Ceraseal. Conclusions: None of the investigated sealers could be totally removed from root canal walls. However, the quantity of remnants of root filling material with well root and ceraseal were significantly more, compared to ADSEAL.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiyu Sun ◽  
Wei Wu ◽  
Limei Tian ◽  
Wei Li ◽  
Fang Zhang ◽  
...  

AbstractNot only does the Dynastes tityus beetle display a reversible color change controlled by differences in humidity, but also, the elytron scale can change color from yellow-green to deep-brown in specified shapes. The results obtained by focused ion beam-scanning electron microscopy (FIB-SEM), show that the epicuticle (EPI) is a permeable layer, and the exocuticle (EXO) is a three-dimensional photonic crystal. To investigate the mechanism of the reversible color change, experiments were conducted to determine the water contact angle, surface chemical composition, and optical reflectance, and the reflective spectrum was simulated. The water on the surface began to permeate into the elytron via the surface elemental composition and channels in the EPI. A structural unit (SU) in the EXO allows local color changes in varied shapes. The reflectance of both yellow-green and deep-brown elytra increases as the incidence angle increases from 0° to 60°. The microstructure and changes in the refractive index are the main factors that influence the process of reversible color change. According to the simulation, the lower reflectance causing the color change to deep-brown results from water infiltration, which increases light absorption. Meanwhile, the waxy layer has no effect on the reflection of light. This study lays the foundation to manufacture engineered photonic materials that undergo controllable changes in iridescent color.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2569
Author(s):  
Mia Kurek ◽  
Nasreddine Benbettaieb ◽  
Mario Ščetar ◽  
Eliot Chaudy ◽  
Maja Repajić ◽  
...  

Chitosan and pectin films were enriched with blackcurrant pomace powder (10 and 20% (w/w)), as bio-based material, to minimize food production losses and to increase the functional properties of produced films aimed at food coatings and wrappers. Water vapor permeability of active films increased up to 25%, moisture content for 27% in pectin-based ones, but water solubility was not significantly modified. Mechanical properties (tensile strength, elongation at break and Young’s modulus) were mainly decreased due to the residual insoluble particles present in blackcurrant waste. FTIR analysis showed no significant changes between the film samples. The degradation temperatures, determined by DSC, were reduced by 18 °C for chitosan-based samples and of 32 °C lower for the pectin-based samples with blackcurrant powder, indicating a disturbance in polymer stability. The antioxidant activity of active films was increased up to 30-fold. Lightness and redness of dry films significantly changed depending on the polymer type. Significant color changes, especially in chitosan film formulations, were observed after exposure to different pH buffers. This effect is further explored in formulations that were used as color change indicators for intelligent biopackaging.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3211
Author(s):  
David Donnermeyer ◽  
Sina Schmidt ◽  
Arno Rohrbach ◽  
Johannes Berlandi ◽  
Sebastian Bürklein ◽  
...  

The aim of this study was to investigate the suitability of rhodamine B dye staining of an epoxy resin sealer (AH Plus) and calcium-silicate-based sealers (Total Fill BC Sealer, BioRoot RCS) to represent the penetration depth of the sealers into dentinal tubules after root canal obturation. In a three-step process, (1) leaching of rhodamine B from sealers into a buffer solution, (2) passive penetration of leached rhodamine B into dentinal tubules, and (3) conformity of rhodamine B penetration assessed by confocal laser scanning microscopy (CLSM), and sealer penetration assessed by scanning electron microscopy (SEM), in root-canal-filled teeth, were evaluated. Rhodamine B dye massively leached out of Total Fill BC Sealer and BioRoot RCS into the phosphate-buffered saline (PBS). A pinkish coloration of AH Plus was found after contact with PBS. Leached rhodamine B dye passively penetrated dentinal tubules from all three sealers when placed on root dentin. No correlation was observed between sealer penetration in SEM and rhodamine B penetration in CLSM. Staining of sealers using rhodamine B is an inadequate method with which to evaluate sealer penetration depth into dentinal tubules, as it overestimates the penetration of sealers into root dentin tubules.


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