scholarly journals Influence of Er, Cr: YSGG (2780 nm) and Nanosecond Nd: YAG Laser (1064 nm) Irradiation on Enamel Acid Resistance: Morphological and Elemental Analysis

2019 ◽  
Vol 7 (11) ◽  
pp. 1828-1833
Author(s):  
Maryam M. El Mansy ◽  
Mostafa Gheith ◽  
Abo M. El Yazeed ◽  
Dina B. E. Farag
Keyword(s):  
Laser Irradiation ◽  
Acid Resistance ◽  
Enamel Surface ◽  
Yag Laser ◽  
Group Iii ◽  
Percentage Decrease ◽  
Group I ◽  
Ph Cycling ◽  
Calcium And Phosphorus ◽  
Scanning Electron

BACKGROUND: Enamel demineralisation is an initial step of the serious dental problem including dental caries, white spot lesions and dental erosion. AIM: Compare the effect of Er, Cr: YSGG (λ = 2780 nm) and nanosecond Nd: YAG (λ = 1064 nm) laser on enamel acid resistance. MATERIAL AND METHODS: Thirty non-carious human premolars, extracted for orthodontic reasons, were used. The experimental groups (n = 10 each group) were: Group I, untreated (control); Group II, Er,Cr:YSGG laser irradiation (0.75 W, 20 Hz, 140 μs, 10 s); Group III, nanosecond pulsed Nd:YAG laser irradiation (0.8 W, 10 Hz, 7 ns, 10 s). Scanning electron microscope and Energy Dispersive X-ray Spectroscopy (EDX) were used to assess acquired enamel resistance to PH cycling. RESULTS: After subjecting the three experimental groups to PH cycling, scanning electron microscopic examination revealed irregular porous dissoluted enamel surface in group I. However, groups II and III demonstrated partially dissoluted enamel surface. EDX analysis demonstrated the lowest mean percentage decrease in calcium and phosphorus content in group II followed by group III, then the highest mean percentage decrease was observed in untreated group I. One-way ANOVA revealed significant differences (p < 0.0001) between the tested groups. CONCLUSIONS: Both Er, Cr: YSSG and nanosecond Nd: YAG laser irradiation were able to improve the acid resistance of enamel. However, enamel surface treated with Er, Cr: YSSG laser showed the lowest mean percentage decrease of calcium and phosphorus (highest acid resistance).

Analysis of surface conditioning methods on core-veneer bond strength of CAD/CAM zirconia restorations

2020 ◽  
pp. 1-11
Author(s):  
Anip K. Roy ◽  
Govind N. Prasad ◽  
Tushar V. Bhagat ◽  
Saurabh Chaturvedi ◽  
Vishwanath Gurumurthy ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Bond Strength ◽  
Shear Bond Strength ◽  
Group Iv ◽  
Control Group ◽  
Group Iii ◽  
Surface Conditioning ◽  
Group I ◽  
Alumina Particles ◽  
Scanning Electron

BACKGROUND: The increased strength of zirconia has resulted in its widespread application in clinical dentistry. Nevertheless, the fracture of veneering porcelains remains one of the key reasons of failure. OBJECTIVE: The objective of this study was to compare and analyze the influence of surface conditioning methods on the core-veneer bond strength of zirconia restorations. METHODS: Thirty specimens of zirconia core with sizes 10 × 5 × 5 mm were layered with porcelain of sizes 5 × 3 × 3 mm. On the basis of different surface conditioning methods, four groups were made: Group I: abrasion with airborne alumina particles of 110 μm size, Group II: sandblasting with silica coated alumina particles of 50 μm in size, Group III (modified group): alteration with a coating of zirconia powder prior to sintering, and Group IV (control group): metal core specimens. The shear force of all specimens was tested using a universal testing machine with a 0.5 mm/min crosshead speed. One-way analysis of variance (ANOVA) and Tukey’s post hoc pair wise comparison (p= 0.05) were performed to analyze the shear bond strength. A scanning electron microscope was used to assess the fractured specimens. RESULTS: A statistically significant difference was noted between the groups. The mean value of shear bond strength was 40.25 MPa for Group I, 41.93 MPa for Group II, 48.08 MPa for Group III and 47.01 MPa for Group IV. CONCLUSIONS: The modified zirconia group and control group demonstrated a significantly higher mean bond strength than that of Group I, where airborne particle abrasion was used. The scanning electron microscope showed that cohesive fracture in the porcelain veneers was the main problem of failure in altered zirconia. The modified zirconia specimens in Group III demonstrated significantly improved values of shear bond strength.

scholarly journals Molecular analysis of Er:YAG laser irradiation on dentin

2006 ◽  
Vol 17 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Luís Eduardo Silva Soares ◽  
Aldo Brugnera Junior ◽  
Fátima Zanin ◽  
Marcos Tadeu Tavares Pacheco ◽  
Airton A. Martin
Keyword(s):  
Raman Spectroscopy ◽  
Laser Irradiation ◽  
Er:Yag Laser ◽  
Chemical Constituents ◽  
Organic Content ◽  
Control Group ◽  
Significance Level ◽  
Group Iii ◽  
Group I ◽  
Group Ii

The aim of this study was to evaluate by dispersive Raman spectroscopy the mineral and organic components of human dentin before and after laser irradiation and acid etching. The occlusal enamel of six non-carious human third molars was removed providing 6 dentin discs, which were divided in four quadrants each of them receiving a different surface treatment: etching with a 37% phosphoric acid gel (control); irradiation by Er:YAG laser (KaVo Key Laser II) with 80 mJ, 3 Hz, 30 s (group I); 120 mJ, 3 Hz, 30 s (group II); and 180 mJ, 3 Hz, 30 s (group III). The Raman spectra of normal (untreated) and treated dentin were analyzed and the mineral and the organic component were evaluated. Results were submitted to statistical analysis by ANOVA and Tukey's test at 5% significance level. The minerals and organic content were less affected in the control group and group I (p>0.05). Group II presented more reduction in mineral content (p<0.01) whereas in group III the inorganic (p<0.05) and organic (p<0.01) content were more affected. Dispersive Raman spectroscopy provided valid information of dentin chemical constituents with non-chemical sampling preparation.

Effect of Enamel Deproteinization in Primary Teeth

2018 ◽  
Vol 42 (1) ◽  
pp. 45-49 ◽  
Author(s):  
Ananthi Christopher ◽  
R Krishnakumar ◽  
N Venugopal Reddy ◽  
G Rohini
Keyword(s):  
Surface Area ◽  
Group Iv ◽  
Enamel Surface ◽  
Tooth Surface ◽  
Type I ◽  
Group Iii ◽  
Group I ◽  
Electron Microscope Analysis ◽  
Group Ii ◽  
Quality Type

Objective: To evaluate and compare the topographical features of enamel surface, etched with different materials. Study Design: 10 extracted human primary molars were randomly selected and cut and trimmed to 1 mm2. Each group comprised of 10 blocks and the enamel was treated as follows: Group I–35% H3PO4; Group II–5.25% NaOCl + 35% H3PO4 ;Group III–5.25% NaOCl; Group IV no treatment was carried out. All the samples were prepared for Scanning electron microscope analysis. The images were obtained and evaluated for the quality type I–II etching of the enamel surface using Auto-CAD 2011 software. Statistical Analysis Used: Wilcoxon Signed Ranks Test (p&lt;0.001). Results: The mean surface area of type I and II etching pattern values for Group- I was 39608.18 μm2 and Group- II was 45051.34 μm2. Conclusion: Deproteinization with 5.25% Sodium hypochlorite prior to acid etching could be used to increase the surface area of adhesion of composite material with the tooth surface.

scholarly journals Alpha-tricalcium phosphate cement in the reconstruction of bone defects in rats

2011 ◽  
Vol 26 (2) ◽  
pp. 135-139 ◽  
Author(s):  
João Gabriel Souza Pinto ◽  
Bruno Tochetto Primo ◽  
Humberto Thomazi Gassen ◽  
Sérgio Augusto Quevedo Miguens Júnior ◽  
Pedro Antonio González Hernández ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bone Repair ◽  
Bone Substitutes ◽  
Bone Defects ◽  
Autogenous Bone ◽  
Group Iii ◽  
Group I ◽  
Male Wistar Rats ◽  
Scanning Electron

PURPOSE: To evaluate the ability of a mixture of α-TCP and autogenous bone (AB) vs. α-TCP alone and AB alone to promote new bone formation and tissue repair in bone defects. METHODS: Bone defects surgically created in 15 male Wistar rats were divided into four groups: Group I (AB), Group II (α-TCP), Group III (α-TCP+AB assessed by light microscopy), and Group IV (α-TCP+AB assessed by scanning electron microscopy). Bone repair findings were assessed at 30, 60, and 120 days postoperatively. RESULTS: The histological findings obtained in Groups I (p=0.459), II (p=0.368), and III (p=0.459) and at 30 days (p=0.717), 60 days (p=0.717), and 120 days (p=0.779) did not show statistically significant differences. Scanning electron microscopy revealed direct contact between the α-TCP+AB implant and the bone tissue at 120 days. CONCLUSION: The α-TCP implant is effective alternative bone substitutes for the treatment of critical size bone defects.

scholarly journals Effect of 17% EDTA on removal of canal wall smear layer and calcium hydroxide dressing: part II

2014 ◽  
Vol 62 (1) ◽  
pp. 53-58
Author(s):  
Rosana de Souza PEREIRA ◽  
Gisela de Souza PEREIRA ◽  
Juliana Machado BARROSO ◽  
Carlos Henrique Siqueira BARROS ◽  
Márcia Gabriella Lino de Barros BORTOLOTTI ◽  
...  
Keyword(s):  
Calcium Hydroxide ◽  
Propylene Glycol ◽  
Root Canal ◽  
Smear Layer ◽  
Canal Wall ◽  
Group Iii ◽  
Group I ◽  
Working Length ◽  
Almost All ◽  
Scanning Electron

OBJECTIVE: the aim of this study was to evaluate, by scanning electron microscopy, the effectiveness of 17% EDTA on removal of canal wall smear layer and calcium hydroxide dressing in different thirds of root canal. METHODS: Ttwenty-four premolars were instrumented in the cervical and middle thirds using Gates-Glidden drills. At the working length, the canal was widened up to # 35 file, followed by scaling up to file # 50. After instrumentation, the teeth were divided into four groups according to the treatment received: GI - irrigation performed with 5 ml of NaOCl 2.5 % ; GII - irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by irrigation with 5 ml of 2.5% NaOCl ; GIII - irrigation with 5 ml of NaOCl 2.5% , drying , application of temporary dressing of Ca (OH )2 with propylene glycol and sealing. After 5 days , removing the sealing irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by a final flush with 5 ml of 2.5% NaOCl ; GIV - irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15 , followed by irrigation with 5 ml of 2.5% NaOCl , drying and after use of the medication in Ca (OH )2 with the sealing and propylene glycol which was removed after 5 days performing the irrigation with 5 ml of 17% EDTA for 2 and a half minutes , submitted to agitation with file # 15, followed by using 5 ml 2.5% NaOCl . Next, the teeth were prepared and taken to the scanning electron microscope . RESULTS: The images revealed: Group I - a marked presence of smear layer in all three thirds, Group II - removal of almost all of the smear layer in the cervical third and removal of large quantity in the middle third, whereas in the apical third a large quantity of smear layer still remained however, in comparison with the other groups, this was shown to be cleaner; Group III - in the three thirds, the presence of smear layer was observed, which was shown to be much less compacted than that observed in Group 1; Group IV- in all the thirds there was reduction of smear layer and Ca(OH)2-based medication, and presence of several unobstructed dentinal tubules could be observed, demonstrating the second best result observed. CONCLUSION: It could be concluded that the use of 17% EDTA favored removal of the smear layer and intracanal medication residues in all thirds of the root canal.

scholarly journals Effect of different irrigation porotocols on root dentine micro-hardness-An invitro study

2021 ◽  
Vol 6 (4) ◽  
pp. 217-221
Author(s):  
Ashish Choudhary ◽  
Sukhbir Kour ◽  
Azhar Malik
Keyword(s):  
Functional Performance ◽  
Test Group ◽  
Direct Consequence ◽  
Group Iv ◽  
Micro Hardness ◽  
Group Iii ◽  
Percentage Decrease ◽  
Group I ◽  
Significant Difference ◽  
Group Ii

IIrrigation solutions used and time of use has a definite effect on the micro hardness & other physical properties of dentin which in turn have direct consequence on the longevity functional performance of root canal treated teeth. To evaluate the effect of different irrigation solutions on micro hardness of root dentin.Forty extracted single rooted lower premolars were used. After instrumentation all the root halves were randomly assigned into 4groups (n=10) and brought in contact with one of the following irrigants for 5 minutes. Group I: 10 ml of 5% Sodium Hypochlorite (NaOCl).Group II: 10 ml of 17% ethylene diamine tetra-acetic acid (EDTA) followed by 10 ml of 5% NaOCl.Group III: 10 ml of 5% NaOCl followed by 10 ml of 2% chlorhexidine digluconate (CHX).Group IV: 10 ml of 5% NaOCL followed by flush of 10 ml distilled water then by 10ml of 2% CHX. Dentin micro hardness was measured at baseline and after treatment to determine the change in micro hardness, using Vickers tester.Data was analyzed using following parametric tests t-test, ANOVA test and Post Hoc test. Group II ie final irrigation with EDTA showed the highest percentage decrease in micro hardness values, followed by group III, then group IV and the lowest was group I. All groups showed a significant difference between each other (P &#60; 0.05), except group III and IV. The coronal third showed the highest percentage decrease with significant difference between apical and middle thirds (P &#60; 0.05).EDTA with NaOCl causes greatest changes in dentine micro hardness, an intermediate flush with normal saline should be given for prevention of precipitation with NaOCl & CHX.

scholarly journals Differences in surface roughness of enamel after whey-extract application and CPP-ACP in post extracoronal-tooth bleaching

2018 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Afiatul Mukarromah ◽  
Irfan Dwiandhono ◽  
Dian Noviyanti Agus Imam
Keyword(s):  
Surface Roughness ◽  
Artificial Saliva ◽  
Enamel Surface ◽  
Tooth Bleaching ◽  
Control Group ◽  
Group Iii ◽  
Group I ◽  
Significant Difference ◽  
Group Ii ◽  
Bleaching Treatment

Demineralization is a process of partial or full tooth mineral loss which caused by acidic environment, for example the side effect of extracoronal bleaching treatment. Demineralization increases enamel surface roughness which leads plaque accumulation. Whey extract and calcium phosphopeptide-amorphous calcium phophate (CPP-ACP) contain calcium and phosphate that can stop the demineralization through remineralization process. This study aimed to determine the differences of enamel surface roughness after whey extract and CPP-ACP application post- extracoronal bleaching. Experimental laboratory with pre- and post-test control group design was performed on 24 first maxillary premolars which devided into 3 groups. On group I, specimens were immersed in artificial saliva. Specimens in group II were immersed in whey extract meanwhile specimens were immersed in CPP-ACP on group III. Whey extract and CPP-ACP immersions were conducted 10 minutes every 12 hours for 15 days. The enamel surface roughness test was performed twice, after extracoronal bleaching treatment and after 15 days remineralization agent application. This study result indicated significant differences between group I and group II and between group I and group III (p<0.05), but there was no significant difference between group II and group III (p>0.05). This study showed whey extract decreased more enamel surface roughness than CPP-ACP but the difference was not significant statistically. So, whey extract and CPP-ACP showed similar remineralization potential.

scholarly journals Shear bond strength of enamel surface treated with air-abrasive system

2002 ◽  
Vol 13 (3) ◽  
pp. 175-178 ◽  
Author(s):  
Maria Cristina Borsatto ◽  
Alma Blásida Elisaur Benitez Catirse ◽  
Regina Guenka Palma Dibb ◽  
Telma Nunes do Nascimento ◽  
Renata Andréa Salvitti de Sá Rocha ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Aluminum Oxide ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Enamel Surface ◽  
Acid Etching ◽  
Air Abrasion ◽  
Group Iii ◽  
Group I

The aim of this study was to evaluate the shear bond strength of a composite resin to dental enamel, using three different surface treatments. Fifteen sound third molars were randomly assigned to three groups. The mesial and distal surfaces were flattened and covered using adhesive tape with a central orifice delimiting the adhesion area (7.07 mm²). Group I, the enamel surface was conditioned with 37% phosphoric acid for 15 s; group II, the surface was treated using air abrasion with aluminum oxide; group III, the enamel surface was treated using an association of air abrasion with aluminum oxide and 37% phosphoric acid. The Single Bond (3M) adhesive system was applied and a Teflon matrix was placed and filled with composite resin Z-100 (3M) and light-cured. The shear bond strength test was performed with a universal testing machine. The acid etching technique and air abrasion with aluminum oxide associated with acid etching had the highest shear bond strength values. Data were subjected to statistical analysis using ANOVA and the Tukey test, and no statistically significant difference in shear bond strength was observed between group I (12.49 ± 2.85 MPa) and group III (12.59 ± 2.68 MPa). In contrast, both groups had statistically better shear bond strengths compared to group II (0.29 ± 0.56 MPa; p<0.05). Air abrasion with aluminum oxide does not substitute acid etching. The association of these methods to obtain adequate adhesion to the substrate is necessary.

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