scholarly journals Surface Deterioration of Indirect Restorative Materials

2020 ◽  
Vol 31 (3) ◽  
pp. 264-271
Author(s):  
Amanda Mahammad Mushashe ◽  
Isabelli Carolini Farias ◽  
Carla Castiglia Gonzaga ◽  
Leonardo Fernandes da Cunha ◽  
Jack Libório Ferracane ◽  
...  
Keyword(s):  
Surface Characteristics ◽  
Ceramic System ◽  
Resin Cements ◽  
Restorative Materials ◽  
Levene Test ◽  
Adhesive Cement ◽  
Hybrid Ceramic ◽  
In Situ Biodegradation

Abstract The objective of this work was to evaluate the effects of in vitro and in situ biodegradation on the surface characteristics of two resin cements and a hybrid ceramic system. One hundred and eighty specimens (4X1.5mm) of each material (Maxcem Elite, NX3 Nexus and Vita Enamic) were made and randomly distributed in twelve groups (n=15) according to the material and biodegradation method. The specimens were then submitted to the following challenges: storage in distilled water 37 ºC for 24 h or 7 days, storage for 7 days, at 37 ºC, in stimulated saliva or in situ. The in situ stage corresponded to the preparation of 15 intraoral palatal devices, used for 7 days. Each device presented 3 niches, where a sample of each materials was accommodated. Specimens from both saliva and in situ groups suffered a cariogenic challenge, corresponding to the application of a solution of 20% of sucrose, 10 times throughout each day. After each biodegradation method, the surface roughness (Ra), Vickers hardness (VHN) and scanning electron microscopy (SEM) analyzes were performed. The data collected were evaluated by Levene test, two-way ANOVA and Tukey`s test (α=5%). The in situ challenge promoted the greater biodegradation, regardless of the material. Regarding the materials, the Vita Enamic VHN was negatively affected by all biodegradation methods and the Nexus NX3 presented better performance than the self-adhesive cement tested. Therefore, within the conditions of this work, it was concluded that in situ biodegradation can affect negatively the surface characteristics of indirect restorative materials.

Does Finishing and Polishing of Restorative Materials Affect Bacterial Adhesion and Biofilm Formation? A Systematic Review

2018 ◽  
Vol 43 (1) ◽  
pp. E37-E52 ◽  
Author(s):  
DAM Dutra ◽  
GKR Pereira ◽  
KZ Kantorski ◽  
LF Valandro ◽  
FB Zanatta
Keyword(s):  
Systematic Review ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Surface Characteristics ◽  
Periodontal Inflammation ◽  
Restorative Materials ◽  
The Impact

SUMMARY Biofilm (bacterial plaque) accumulation on the surface of restorative materials favors the occurrence of secondary caries and periodontal inflammation. Surface characteristics of restorations can be modified by finishing and/or polishing procedures and may affect bacterial adhesion. The aim of this systematic review was to characterize how finishing and polishing methods affect the surface properties of different restorative materials with regard to bacterial adhesion and biofilm formation. Searches were carried out in MEDLINE-PubMed, EMBASE, Cochrane-CENTRAL, and LILACS databases. From 2882 potential articles found in the initial searches, only 18 met the eligible criteria and were included in this review (12 with in vitro design, four with in situ design, and two clinical trials). However, they presented high heterogeneity regarding materials considered and methodology for evaluating the desired outcome. Risk bias analysis showed that only two studies presented low risk (whereas 11 showed high and five showed medium risk). Thus, only descriptive analyses considering study design, materials, intervention (finishing/polishing), surface characteristics (roughness and surface free energy), and protocol for biofilm formation (bacterial adhesion) could be performed. Some conclusions could be drawn: the impact of roughness on bacterial adhesion seems to be related not to a roughness threshold (as previously believed) but rather to a range, the range of surface roughness among different polishing methods is wide and material dependent, finishing invariably creates a rougher surface and should always be followed by a polishing method, each dental material requires its own treatment modality to obtain and maintain as smooth a surface as possible, and in vitro designs do not seem to be powerful tools to draw relevant conclusions, so in vivo and in situ designs become strongly recommended.

In Situ Surface Biodegradation of Restorative Materials

2014 ◽  
Vol 39 (4) ◽  
pp. 349-360 ◽  
Author(s):  
GC Padovani ◽  
SBP Fúcio ◽  
GMB Ambrosano ◽  
MAC Sinhoreti ◽  
RM Puppin-Rontani
Keyword(s):  
Chemical Composition ◽  
Surface Characteristics ◽  
Sem Images ◽  
Dental Biofilm ◽  
Initial Chemical Composition ◽  
Restorative Materials ◽  
Dependent Parameter ◽  
Kolmogorov Smirnov ◽  
In Situ Biodegradation

SUMMARY This study aimed to evaluate the surface characteristics of restorative materials (roughness, hardness, chemical changes by energy-dispersive spectroscopy [EDX], and scanning electron microscopy [SEM]) submitted to in situ biodegradation. Fifteen discs of each material (IPS e.max [EM], Filtek Supreme [FS], Vitremer [VI], Ketac Molar Easymix [KM], and Amalgam GS-80 [AM]) were fabricated in a metallic mold (4.0 mm × 1.5 mm). Roughness, hardness, SEM, and EDX were then evaluated. Fifteen healthy volunteers used a palatal device containing one disc of each restorative material for seven days. After the biodegradation, the roughness, hardness, SEM, and EDX were once again evaluated. Data obtained from the roughness and hardness evaluations were submitted to Kolmogorov-Smirnov and Tukey-Kramer tests (p<0.05). All esthetic restorative materials showed a significant increase in the roughness after biodegradation. Before biodegradation, significant differences in the hardness among the materials were seen: EM>AM>FS>KM>VI. After biodegradation, the hardness was significantly altered among the materials studied: EM>AM>FS=KM>VI, along with a significant increase in the hardness for AM, KM, and VI. SEM images indicated degradation on the surface of all materials, showing porosities, cracks, and roughness. Furthermore, after biodegradation, FS showed the presence of Cl, K, and Ca on the surface, while F was not present on the VI and KM surfaces. EM and AM did not have alterations in their chemical composition after biodegradation. It was concluded that the dental biofilm accumulation in situ on different restorative materials is a material-dependent parameter. Overall, all materials changed after biodegradation: esthetic restorative materials showed increased roughness, confirmed by SEM, and the ionomer materials and silver amalgam showed a significantly higher hardness. Finally, the initial chemical composition of the composite resin and ionomer materials evaluated was significantly altered by the action of the biofilm in situ.

Evaluation of polymerization shrinkage of resin cements through in vitro and in situ experiments

2014 ◽  
Author(s):  
A. P. G. O. Franco ◽  
L. Z. Karam ◽  
C. A. Pulido ◽  
O. M. M. Gomes ◽  
H. J. Kalinowski
Keyword(s):  
Resin Cements ◽  
Polymerization Shrinkage ◽  
In Situ Experiments

In Vitro and In Situ Fiber Bragg Grating Sensor Analysis of Two Dental Resin Cements

2015 ◽  
Vol 33 (12) ◽  
pp. 2543-2548 ◽  
Author(s):  
Leandro Zen Karam ◽  
Ana Paula G. de O. Franco ◽  
Camilo A. Pulido ◽  
Osnara Maria Mongruel Gomes ◽  
Hypolito J. Kalinowski
Keyword(s):  
Fiber Bragg Grating ◽  
Fiber Bragg Grating Sensor ◽  
Bragg Grating ◽  
Dental Resin ◽  
Resin Cements ◽  
Sensor Analysis ◽  
Bragg Grating Sensor

scholarly journals Evaluation of the Effect of a Home Bleaching Agent on Surface Characteristics of Indirect Esthetic Restorative Materials—Part II Microhardness

2014 ◽  
Vol 15 (4) ◽  
pp. 438-443 ◽  
Author(s):  
Mahroo Vojdani ◽  
Kianoosh Torabi ◽  
Sasan Rasaeipour ◽  
Safoura Ghodsi ◽  
Amir Ali Reza Khaledi
Keyword(s):  
Surface Preparation ◽  
Surface Characteristics ◽  
Distilled Water ◽  
Bleaching Agent ◽  
Reinforced Composite ◽  
Restorative Materials ◽  
Most Significant Change ◽  
Knoop Microhardness ◽  
Negative Controls

ABSTRACT Background The exponential usage of esthetic restorative materials is beholden to society needs and desires. Interaction between the bleaching agents and the esthetic restorative materials is of critical importance. Aim This in vitro study has been conducted to evaluate the effect of a home bleaching agent, carbamide peroxide (CP) 38%, on the microhardness of the fiber reinforced composite (FRC), overglazed, autoglazed, or polished porcelain specimens. Materials and methods For overglazed, autoglazed, polished ceramics and also FRC cylindrical specimens (n = 20 per group) were prepared. The specimens were stored in distilled water at 37°C for 48 hours prior to testing. Six samples from each group were selected randomly as negative controls which were stored in distilled water at 37°C that was changed daily. CP 38% was applied on the test specimens for 15 minutes, twice a day for 14 days. By using Knoop-microhardness tester microhardness testing for baseline, control and test specimens was conducted. Data were statistically analyzed using paired t-test, Mann- Whitney test, and Kruskal-Wallis test. Results Home bleaching significantly decreased the surface microhardness of all the test samples (p < 0.05), whereas the control groups did not show statistically significant changes after 2 weeks. The polished porcelain and polished composite specimens showed the most significant change in microhardness after bleaching process (p < 0.05). Conclusion Although the type of surface preparation affects the susceptibility of the porcelain surface to the bleaching agent, no special preparation can preclude such adverse effects. Clinical Significance The contact of home bleaching agents with esthetic restorative materials is unavoidable. Therefore protecting these restorations from bleaching agents and reglazing or at least polishing the restorations after bleaching is recommended. How to cite this article Torabi K, Rasaeipour S, Ghodsi S, Khaledi AAR, Vojdani M. Evaluation of the Effect of a Home Bleaching Agent on Surface Characteristics of Indirect Esthetic Restorative Materials — Part II Microhardness. J Contemp Dent Pract 2014;15(4):438-443.

scholarly journals DEVELOPMENT OF A GFP‐BASED BIOSENSOR FOR DETECTING THE BIOAVAILABILITY AND BIODEGRADATION OF POLYCHLORINATED BIPHENYLS (PCBS)

2007 ◽  
Vol 15 (4) ◽  
pp. 261-268 ◽  
Author(s):  
Xuemei Liu ◽  
Kieran J. Germaine ◽  
David Ryan ◽  
David N. Dowling
Keyword(s):  
Benzoic Acid ◽  
Polychlorinated Biphenyl ◽  
In Vitro Tests ◽  
Chlorobenzoic Acid ◽  
Fluorescent Intensity ◽  
Chemical Inducers ◽  
Benzoic Acid Derivatives ◽  
In Situ Biodegradation

Two whole-cell biosensors were constructed to detect the in situ biodegradation of polychlorinated biphenyl by chromosomal insertion of a mini‐Tn5‐Kmr‐Pm::gfp[mut3]‐T0‐T1 construct into P. fluorescens. In vitro tests showed that the expression of the Pm promoter depended on the growth phase of the biosensors and the concentration of chemical inducers; chlorinated benzoic acid derivatives. A linear relationship between the fluorescent intensity and the log10 concentration of the inducer was observed. One biosensor (F113L::1180gfp) had the ability to degrade PCBs to relevant chlorobenzoic acid derivatives and to induce expression of Gfp. The second biosensor (F113gfp), which cannot degrade PCBs, shows fluorescence after induction by chloro‐benzoic acid derivatives. By using these two biosensors, PCB degradation could be detected in vitro and in soil.

scholarly journals Effects of ultrasonic scaling on the optical properties and surface characteristics of highly translucent CAD/CAM ceramic restorative materials: An in vitro study

2019 ◽  
Vol 45 (12) ◽  
pp. 14594-14601 ◽  
Author(s):  
Jae-Hyun Lee ◽  
Sung-Hun Kim ◽  
Jung-Suk Han ◽  
In-Sung Luke Yeo ◽  
Hyung-In Yoon ◽  
...  
Keyword(s):  
Optical Properties ◽  
In Vitro Study ◽  
Surface Characteristics ◽  
Vitro Study ◽  
Restorative Materials ◽  
Cad Cam

scholarly journals Establishment of novel in vitro culture system with the ability to reproduce oral biofilm formation on dental materials

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tomoki Kohno ◽  
Haruaki Kitagawa ◽  
Ririko Tsuboi ◽  
Yuma Nishimura ◽  
Satoshi Imazato
Keyword(s):  
Culture System ◽  
Volume Fraction ◽  
Sucrose Solution ◽  
Glass Ionomer Cement ◽  
Bacterial Suspension ◽  
Bacterial Cells ◽  
Oral Biofilm ◽  
Restorative Materials

AbstractIntensive research has been conducted with the aim of developing dental restorative/prosthetic materials with antibacterial and anti-biofilm effects that contribute to controlling bacterial infection in the oral cavity. In situ evaluations were performed to assess the clinical efficacy of these materials by exposing them to oral environments. However, it is difficult to recruit many participants to collect sufficient amount of data for scientific analysis. This study aimed to assemble an original flow-cell type bioreactor equipped with two flow routes and assess its usefulness by evaluating the ability to reproduce in situ oral biofilms formed on restorative materials. A drop of bacterial suspension collected from human saliva and 0.2% sucrose solution was introduced into the assembled bioreactor while maintaining the incubation conditions. The bioreactor was able to mimic the number of bacterial cells, live/dead bacterial volume, and volume fraction of live bacteria in the in situ oral biofilm formed on the surface of restorative materials. The usefulness of the established culture system was further validated by a clear demonstration of the anti-biofilm effects of a glass-ionomer cement incorporating zinc-releasing glasses when evaluated by this system.

Correlated Studies of Cellular Interactions Using TEM, Freeze Etching, and SEM

1974 ◽  
Vol 32 ◽  
pp. 320-321
Author(s):  
J. P. Revel
Keyword(s):  
Developmental Stages ◽  
Three Dimensional ◽  
Cell Movement ◽  
Cellular Interactions ◽  
Serial Sections ◽  
Cell Sheets ◽  
Freeze Etching ◽  
Early Developmental

Movement of individual cells or of cell sheets and complex patterns of folding play a prominent role in the early developmental stages of the embryo. Our understanding of these processes is based on three- dimensional reconstructions laboriously prepared from serial sections, and from autoradiographic and other studies. Many concepts have also evolved from extrapolation of investigations of cell movement carried out in vitro. The scanning electron microscope now allows us to examine some of these events in situ. It is possible to prepare dissections of embryos and even of tissues of adult animals which reveal existing relationships between various structures more readily than used to be possible vithout an SEM.

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