scholarly journals Pellicle Modification with Casein and Mucin Does Not Affect Surface Loss from Erosion and Abrasion

2020 ◽  
Vol 54 (5-6) ◽  
pp. 509-516
Author(s):  
Tommy Baumann ◽  
Christoph Schmidt ◽  
Thiago Saads Carvalho
Keyword(s):  
In Vitro Study ◽  
Human Saliva ◽  
Ctrl Group ◽  
Protein Mixture ◽  
Surface Loss ◽  
Human Enamel ◽  
Optical Profilometer ◽  
And Control ◽  
Protein Treatment

<b><i>Aim:</i></b> A combination of the proteins casein and mucin is known to modify the salivary pellicle and improve its protection of the underlying enamel from erosion. It is so far not known if this protection is confined solely to erosion, or if it also extends to abrasion, and this in vitro study aimed at investigating this question. <b><i>Methods:</i></b> A total of 72 human enamel specimens were prepared and randomly assigned to four groups: pellicle (P), casein/mucin (CM), pellicle + casein/mucin (PCM), and control (Ctrl). Each specimen underwent five cycles, each cycle consisting of a pellicle/treatment part, an erosion part (3 min in 1% citric acid, pH 3.6, 25°C, 70 rpm), and an abrasion part (50 toothbrush strokes within 25 s in toothpaste slurry with a 200-g load). The pellicle/treatment part consisted of 2 h of incubation in whole human saliva for group P, 2 h of incubation (25°C, 70 rpm) in a protein mixture of 1% casein and 0.27% mucin for group CM, and 2 h of incubation in saliva followed by 2 h of incubation in the protein mixture for group PCM. The fourth group (Ctrl) served as the control and was kept in a humid chamber without saliva or protein treatment. The enamel surfaces were scanned with an optical profilometer initially and after the final cycle, and surface loss was analyzed. Furthermore, the surface microhardness (SMH) was measured initially, after each pellicle/treatment part and each erosion cycle, and after the final abrasion cycle. The results were analyzed with Kruskal-Wallis and Wilcoxon tests with Bonferroni corrections. <b><i>Results:</i></b> The different treatments did not show differences in surface loss and therefore did not protect enamel from surface loss by abrasion. Nonetheless, we observed differences in the SMH values, namely the Ctrl group being significantly softer than the experimental groups. <b><i>Conclusion:</i></b> The observed differences in SMH suggest that a different abrasion protocol could lead to differences in surface loss, and further investigation of whether and under which conditions pellicle modification leads to increased resistance to abrasion remains worthwhile.

scholarly journals Effects of Two In-Office Bleaching Agents with Different pH on the Structure of Human Enamel: An In Situ and In Vitro Study

2013 ◽  
Vol 38 (1) ◽  
pp. 100-110 ◽  
Author(s):  
Y Sa ◽  
L Sun ◽  
Z Wang ◽  
X Ma ◽  
S Liang ◽  
...  
Keyword(s):  
Artificial Saliva ◽  
In Vitro Study ◽  
Storage Condition ◽  
Human Saliva ◽  
Low Ph ◽  
Force Microscopy ◽  
Human Enamel ◽  
And Control

SUMMARY This study evaluated the effects of two in-office bleaching agents (Beyond and Opalescence Boost) with different pH on the structure and mechanical properties of human enamel in vitro and in situ. One hundred and eight enamel slabs were obtained from freshly extracted premolars. The specimens were randomly distributed into nine groups (n=12), and the human saliva (HS) in the volunteers' oral cavities was used to simulate the in situ condition: Beyond + HS, Opalescence Boost (O-Boost) + HS, Control + HS, Beyond + artificial saliva (AS), O-Boost + AS, Control + AS, Beyond + distilled water (DW), O-Boost + DW, and Control + DW. The bleaching treatments were performed on the first and eighth day, and the total bleaching time was 90 minutes. Baseline and final surface roughness (RMS), surface morphology, microhardness, and fracture toughness (FT) were measured before the treatment and on the fifteenth day, respectively. Compared with control groups, surface alterations on enamel were found in the Beyond + AS and Beyond + DW groups under atomic force microscopy evaluation. Two-way analysis of variance and Tukey test revealed that the RMS showed significant intergroup differences for both storage condition and bleaching agent, whereas microhardness and FT revealed no significant alteration. The results indicated that in-office bleaching agents with low pH values could induce enamel morphology alterations under in vitro conditions. The presence of natural HS could eliminate the demineralization effect caused by low pH.

EFFECT OF HUMAN ENAMEL ON WEAR OF THREE TYPES OF INTERIM RESTORATIVE MATERIALS (AN IN-VITRO STUDY)

2017 ◽  
Vol 63 (4) ◽  
pp. 3933-3945
Author(s):  
Khaled Haggag ◽  
Muhammad Abbas ◽  
Zainab EL Sharkawy
Keyword(s):  
In Vitro Study ◽  
Vitro Study ◽  
Human Enamel ◽  
Restorative Materials

scholarly journals SEM Analysis of Enamel Abrasion after Air Polishing Treatment with Erythritol, Glycine and Sodium Bicarbonate

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 549 ◽  
Author(s):  
Bruna Sinjari ◽  
Gianmaria D’Addazio ◽  
Martina Bozzi ◽  
Manlio Santilli ◽  
Tonino Traini ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Sodium Bicarbonate ◽  
Air Flow ◽  
Dental Enamel ◽  
In Vitro Study ◽  
Sem Analysis ◽  
Medical Systems ◽  
Air Polishing ◽  
And Control

The aim of this in vitro study was to evaluate the enamel surface topography after treatment with three air polishing powders: Glycine (A), erythritol (B), and sodium bicarbonate (C) (Air Flow Soft, Plus and Classic powders, EMS Electro Medical Systems S.A., Nyon, Switzerland). Fifteen extracted incisors were randomly divided into three groups of five teeth each, A, B and C, respectively. The teeth were blocked in plaster bases, washed, dried and half-covered with polytetrafluoroethylene strips before treatment. In this way, each half-treated dental element became test and control of itself. Comparative statistical analysis of Rq (geometric average of the deviations occurring in roughness profile) was performed. The scanning electron microscope (SEM) analysis showed different degrees of surface roughness between the groups, decreasing after treatment. In addition, a statistically significant reduction p < 0.05 was present in group C (Rq mean non-treated 108.17 µm, 95% CI: 97.29–124.01 and Rq mean treated 86.78 µm, 95% CI: 80.63–93.70). A decrease in surface roughness post-treatment was not observed in group A and B. Therefore, it may be concluded that the air flow powders tested herein can be used on dental enamel to reduce the surface roughness due to function and the action of dental therapies.

scholarly journals The Accuracy and Reliability of Tooth Shade Selection Using Different Instrumental Techniques: An In Vitro Study

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7490
Author(s):  
Nattapong Sirintawat ◽  
Tanyaporn Leelaratrungruang ◽  
Pongsakorn Poovarodom ◽  
Sirichai Kiattavorncharoen ◽  
Parinya Amornsettachai
Keyword(s):  
Intraclass Correlation ◽  
In Vitro Study ◽  
Control Group ◽  
Intraoral Scanner ◽  
Control Groups ◽  
B Values ◽  
Cie Lab ◽  
And Control ◽  
Shade Selection

This study aimed to investigate and compare the reliability and accuracy of tooth shade selection in the model using 30 milled crowns via five methods: (1) digital single-lens reflex (DSLR) camera with twin flash (TF) and polarized filter (DSLR + TF), (2) DSLR camera with a ring flash (RF) and polarized filter (DSLR + RF), (3) smartphone camera with light corrector and polarized filter (SMART), (4) intraoral scanner (IOS), and (5) spectrophotometer (SPEC). These methods were compared with the control group or manufacturer’s shade. The CIE Lab values (L, a, and b values) were obtained from five of the methods to indicate the color of the tooth. Adobe Photoshop was used to generate CIE Lab values from the digital photographs. The reliability was calculated from the intraclass correlation based on two repetitions. The accuracy was calculated from; (a) ΔE calculated by the formula comparing each method to the control group, (b) study and control groups were analyzed by using the Kruskal–Wallis test, and (c) the relationship between study and control groups were calculated using Spearman’s correlation. The reliability of the intraclass correlation of L, a, and b values obtained from the five methods showed satisfactory correlations ranging from 0.732–0.996, 0.887–0.994, and 0.884–0.999, respectively. The ΔE from all groups had statistically significant differences when compared to the border of clinical acceptance (ΔE = 6.8). The ΔE from DSLR + TF, DSLR + RF, SMART, and SPEC were higher than clinical acceptance (ΔE > 6.8), whereas the ΔE from IOS was 5.96 and all of the L, a, and b values were not statistically significantly different from the manufacturer’s shade (p < 0.01). The ΔE of the DSLR + RF group showed the least accuracy (ΔE = 19.98), whereas the ∆E of DSLR + TF, SMART, and SPEC showed similar accuracy ∆E (ΔE = 10.90, 10.57, and 11.57, respectively). The DSLR camera combined with a ring flash system and polarized filter provided the least accuracy. The intraoral scanner provided the highest accuracy. However, tooth shade selection deserves the combination of various techniques and a professional learning curve to establish the most accurate outcome.

scholarly journals Evaluation of Apical Sealing Ability of Four Different Sealers using Centrifuging Dye Penetration Method: An in vitro Study

2012 ◽  
Vol 13 (6) ◽  
pp. 830-833
Author(s):  
Romel Joseph
Keyword(s):  
In Vitro Study ◽  
Blue Dye ◽  
Control Groups ◽  
Root Canals ◽  
Dye Penetration ◽  
Gutta Percha ◽  
Sealing Ability ◽  
Ah Plus ◽  
And Control

ABSTRACT Aim The aim of this in vitro study was to evaluate the apical seal obtained with four root canal sealers AH 26, Sealapex, Endoflas FS and AH Plus, with lateral condensation. Materials and methods Sixty root canals were prepared using the step-back technique. The specimens were divided into four experimental groups of 12 teeth and two control groups of 12 teeth. The experimental groups were obturated by laterally condensed gutta-percha with one of the tested sealers and control groups were obturated without any sealer. Methylene blue dye penetration with centrifuging method was used to evaluate the apical sealing ability. The quantitative apical leakage of each specimen was measured after 2 weeks. Results The results showed no significant differences between all groups except between AH Plus and Endoflas FS (<0.05). AH Plus showed significantly less leakage than Endoflas FS. Conclusion AH Plus showed the least leakage compared to AH 26, Sealapex and Endoflas FS. How to cite this article Joseph R, Singh S. Evaluation of Apical Sealing Ability of Four Different Sealers using Centrifuging Dye Penetration Method: An in vitro Study. J Contemp Dent Pract 2012;13(6):830-833.

scholarly journals Adhesion of Two Bonding Systems to Air-Abraded or Bur-Abraded Human Enamel Surfaces

2008 ◽  
Vol 02 (03) ◽  
pp. 167-175 ◽  
Author(s):  
Abdulkadir Sengun ◽  
Hasan Orucoglu ◽  
Ilknur Ipekdal ◽  
Fusun Ozer
Keyword(s):  
Bond Strength ◽  
Composite Resin ◽  
In Vitro Study ◽  
Air Abrasion ◽  
Adhesive Resin ◽  
Bonding Performance ◽  
Human Enamel ◽  
Bond Strengths ◽  
Bonding Systems

ABSTRACTObjectives: The purpose of this in vitro study was to evaluate whether mechanical alteration of the enamel surfaces with air abrasion and bur abrasion techniques could enhance the bonding performance of a three step and a self etching adhesive resin systems to enamel.Methods: 126 extracted lower human incisor teeth were used. The teeth were divided into three groups including 40 teeth each. First group; teeth were used as control and no preparation was made on enamel surfaces, 2nd group; outer enamel surfaces were air abraded, 3rd group; outer enamel surfaces were abraded mechanically with a diamond fissure bur. Cylinder composite resin blocks were bonded to the buccal enamel surfaces with two bonding systems (20 specimens in each group). Bond strengths to enamel surfaces were measured at a cross-head speed of 1 mm/min. The data were analyzed by ANOVA and Duncan Tests. To examine interface composite resin/enamel surfaces at scanning electron microscopy, remaining 6 teeth were used. Fracture analysis was performed using an optical stereomicroscope.Results: Bond strengths values of Solid Bond were significantly higher than bond strengths of Clearfil SE Bond for all types of enamel (P<.05). Shear bond strength values obtained with Solid Bond (three step system) to three types of enamel surfaces [air-abraded (30.25±7.00 MPa), bur-abraded (29.07±3.53 MPa), control (31.74±7.35 MPa)] were close to each other (P>.05). The macroscopic mode of failures for bonding systems, SB and SE Bond appeared to be adhesive and cohesive in nature.Conclusions: In order to get better bond strength values with self etching systems, it is advisable to prepare enamel surfaces with bur or air abrasion, but it enamel preparation is not necessary for three step systems. (Eur J Dent 2008;2:167-175)

scholarly journals Metals and Metalloids Release from Orthodontic Elastomeric and Stainless Steel Ligatures: In Vitro Risk Assessment of Human Exposure

2019 ◽  
Vol 196 (2) ◽  
pp. 646-653 ◽  
Author(s):  
Aneta Olszewska ◽  
Anetta Hanć ◽  
Danuta Barałkiewicz ◽  
Piotr Rzymski
Keyword(s):  
Stainless Steel ◽  
Inductively Coupled Plasma ◽  
Human Exposure ◽  
Orthodontic Treatment ◽  
In Vitro Study ◽  
Human Saliva ◽  
Metal Exposure ◽  
Monthly Basis ◽  
Metal Levels

Abstract Elastomeric ligatures are increasingly used as a part of esthetic orthodontic treatment, particularly in children. The aim of the present study was to experimentally test whether these appliances may contribute to exposure to toxic elements. In the present study, elastomeric ligatures (ELs) were incubated in artificial human saliva for 1 month (a typical period of their use) and the release of 21 metals (Ba, Cd, Co, Cr, Cu, Fe, Li, Mn, Mg, Mo, Ni, Pb, Rb, Tl, Ti, Sb, Sr, Sn, Zn, U, V) and 2 metalloids (As and Ge) was studied using inductively coupled plasma–mass spectrometry. For comparison, stainless steel ligatures (SLs) were incubated for 1, 3, and 6 months (since sometimes their use is prolonged) under similar conditions. The determined metal levels were compared to the corresponding safety limits for human exposure. During 1 month, the ELs released Cd, Co, Cr, Mn, Ni, and Sn at total mean ± SD level of 0.31 ± 0.09, 0.98 ± 0.30, 3.96 ± 1.31, 14.7 ± 8.5, 13.8 ± 4.8, and 49.5 ± 27.7 μg, respectively. Other elements were always below the detection limits. In case of SL, the release of Co, Cr, Fe, Ni, Mn, and Sn was observed, and the determined values increased over the studied period. After 6 months, their total mean ± SD levels amounted to 28.6 ± 0.2, 21.7 ± 0.2, 623.5 ± 3.0, 1152.7 ± 1.8, 5.5 ± 0.3, and 22.6 ± 0.2 μg, respectively. The released metal levels from both ligature types were always below safety limits. The release of Ni from SL during 6 months would constitute 5.0 and 11.5% of tolerable intake in adults and children, respectively. The results of this in vitro study highlight that the use of ligatures in orthodontic treatment can be considered safe in terms of metal exposure although elastic ligatures replaced on a monthly basis appear to be advantageous in comparison to the prolonged use of stainless steel appliances.

scholarly journals Effect of surface treatment on the shear bond strength of a resin-based cement to porcelain

2006 ◽  
Vol 17 (4) ◽  
pp. 290-295 ◽  
Author(s):  
Marcos Paulo Nagayassu ◽  
Luciana Keiko Shintome ◽  
Eduardo Shigueyuki Uemura ◽  
José Eduardo Junho de Araújo
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Hydrofluoric Acid ◽  
Shear Bond Strength ◽  
In Vitro Study ◽  
Resin Cement ◽  
Vitro Study ◽  
Acid Etching ◽  
And Control

The purpose of this in vitro study was to evaluate the effect of different surface treatments on the shear bond strength of a resin-based cement to porcelain. Sixty pairs of 50% aluminous porcelain discs were fabricated. In each pair, one disc measured 6 mm in diameter X 3 mm thickness (A) and the other measured 3 mm in diameter X 3mm thickness (B). The specimens were randomly assigned to 6 groups (n=10 pairs of discs), according to the surface treatment: etching with 10% hydrofluoric acid for 2 or 4min (G1 and G2); 50-µm particle aluminum oxide sandblasting for 5 s (G3); sandblasting followed by etching for 2 or 4min (G4 and G5) and control - no treatment (G6). A silane agent was applied to the treated surface of both discs of each pair. Bistite II DC dual-cure resin cement was applied and the B discs were bonded to their respective A discs. Specimens were stored in distilled water at 37ºC for 24 h and were tested in shear strength at a crosshead speed of 2 mm/min. Means in MPa were: G1: 14.21 ± 4.68; G2: 8.92 ± 3.02; G3: 10.04 ± 2.37; G4: 12.74 ± 5.15; G5: 10.99 ± 3.35; G6: 6.09 ± 1.84. Data were compared by one-way ANOVA and Tukey's test at 5% significance level. Bond strength recorded after 2-min acid etching was significantly higher than 4-min etching (p<0.05) and control (p<0.05), but did not differ significantlyfrom sandblasting alone (p>0.05) or followed by etching for 2 or 4 min (p>0.05). Within the limitations of an in vitro study, it may be concluded that 2-min hydrofluoric acid etching produced a favorable micromechanical retention that enhanced resin cement bond strength to porcelain.

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