Effects of Pulsed Nd:YAG Laser on Tensile Bond Strength and Caries Resistance of Human Enamel

2014 ◽  
Vol 39 (3) ◽  
pp. 273-282 ◽  
Author(s):  
X Wen ◽  
L Zhang ◽  
R Liu ◽  
M Deng ◽  
Y Wang ◽  
...  

SUMMARY This study aims to evaluate the effects of pulsed Nd:YAG laser on the tensile bond strength (TBS) of resin to human enamel and caries resistance of human enamel. A total of 201 human premolars were used in this in vitro study. A flat enamel surface greater than 4 × 4 mm in area was prepared on each specimen using a low-speed cutting machine under a water coolant. Twenty-one specimens were divided into seven groups for morphology observations with no treatment, 35% phosphoric acid etching (30 seconds), and laser irradiation (30 seconds) of pulsed Nd:YAG laser with five different laser-parameter combinations. Another 100 specimens were used for TBS testing. They were embedded in self-cured acrylic resin and randomly divided into 10 groups. After enamel surface pretreatments according to the group design, resin was applied. The TBS values were tested using a universal testing machine. The other 80 specimens were randomly divided into eight groups for acid resistance evaluation. Scanning electron microscope (SEM) results showed that the enamel surfaces treated with 1.5 W/20 Hz and 2.0 W/20 Hz showed more etching-like appearance than those with other laser-parameter combinations. The laser-parameter combinations of 1.5 W/15 Hz and 1.5 W/20 Hz were found to be efficient for the TBS test. The mean TBS value of 14.45 ± 1.67 MPa in the laser irradiated group was significantly higher than that in the untreated group (3.48 ± 0.35 MPa) but lower than that in the 35% phosphoric acid group (21.50 ± 3.02 MPa). The highest mean TBS value of 26.64 ± 5.22 MPa was identified in the combination group (laser irradiation and then acid etching). Acid resistance evaluation showed that the pulsed Nd:YAG laser was efficient in preventing enamel demineralization. The SEM results of the fractured enamel surfaces, resin/enamel interfaces, and demineralization depths were consistent with those of the TBS test and the acid resistance evaluation. Pulsed Nd:YAG laser as an enamel surface pretreatment method presents a potential clinical application, especially for the caries-susceptible population or individuals with recently bleached teeth.

2015 ◽  
Vol 34 (2) ◽  
pp. 219-226 ◽  
Author(s):  
Hiroshi NOGAWA ◽  
Hiroyasu KOIZUMI ◽  
Osamu SAIKI ◽  
Haruto HIRABA ◽  
Mitsuo NAKAMURA ◽  
...  

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 ◽  
...  

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.


1997 ◽  
Vol 11 (4) ◽  
pp. 245-248 ◽  
Author(s):  
Carlos de Paula EDUARDO ◽  
Wilson Tavares de OLIVEIRA JUNIOR ◽  
Silvio Issáo MYAKI ◽  
Denise Maria ZEZELL

This study has been focused on a comparison between the shear bond strength of a composite resin attached to dental enamel surface, after a 35% phosphoric acid etching and after a Nd:YAG laser irradiation with 165.8 J/cm2 of energy density per pulse. After etching and attaching resin to these surfaces, the specimens were thermocycled and then underwent the shearing bond strength tests at a speed of 5 mm/min. The results achieved, after statistical analysis with Student's t-test, showed that the adhesion was significantly greater in the 35% phosphoric acid treated group than in the group treated with the Nd:YAG laser, thus demonstrating the need for developing new studies to reach the ideal parameters for an effective enamel surface conditioning as well as specific adhesives and composite resins when Nd:YAG laser is used


2015 ◽  
Vol 20 (4) ◽  
pp. 51-56 ◽  
Author(s):  
João Paulo Fragomeni Stella ◽  
Andrea Becker Oliveira ◽  
Lincoln Issamu Nojima ◽  
Mariana Marquezan

OBJECTIVE: To assess four different chemical surface conditioning methods for ceramic material before bracket bonding, and their impact on shear bond strength and surface integrity at debonding.METHODS: Four experimental groups (n = 13) were set up according to the ceramic conditioning method: G1 = 37% phosphoric acid etching followed by silane application; G2 = 37% liquid phosphoric acid etching, no rinsing, followed by silane application; G3 = 10% hydrofluoric acid etching alone; and G4 = 10% hydrofluoric acid etching followed by silane application. After surface conditioning, metal brackets were bonded to porcelain by means of the Transbond XP system (3M Unitek). Samples were submitted to shear bond strength tests in a universal testing machine and the surfaces were later assessed with a microscope under 8 X magnification. ANOVA/Tukey tests were performed to establish the difference between groups (α= 5%).RESULTS: The highest shear bond strength values were found in groups G3 and G4 (22.01 ± 2.15 MPa and 22.83 ± 3.32 Mpa, respectively), followed by G1 (16.42 ± 3.61 MPa) and G2 (9.29 ± 1.95 MPa). As regards surface evaluation after bracket debonding, the use of liquid phosphoric acid followed by silane application (G2) produced the least damage to porcelain. When hydrofluoric acid and silane were applied, the risk of ceramic fracture increased.CONCLUSIONS: Acceptable levels of bond strength for clinical use were reached by all methods tested; however, liquid phosphoric acid etching followed by silane application (G2) resulted in the least damage to the ceramic surface.


2009 ◽  
Vol 28 (4) ◽  
pp. 419-425 ◽  
Author(s):  
Shinya HORIUCH ◽  
Kazuyuki KANEKO ◽  
Hiroko MORI ◽  
Emi KAWAKAMI ◽  
Takashi TSUKAHARA ◽  
...  

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2902
Author(s):  
Phoebe Burrer ◽  
Hoang Dang ◽  
Matej Par ◽  
Thomas Attin ◽  
Tobias T. Tauböck

This study investigated the effect of over-etching and prolonged application time of a universal adhesive on dentin bond strength. Ninety extracted human molars were ground to dentin and randomly allocated into nine groups (G1–9; n = 10 per group), according to the following acid etching and adhesive application times. In the control group (G1), phosphoric acid etching was performed for 15 s followed by application of the universal adhesive Scotchbond Universal (3M) for 20 s, as per manufacturer’s instructions. In groups G2–5, both the etching and adhesive application times were either halved, doubled, quadrupled, or increased eightfold. In groups G6–9, etching times remained the same as in G2–5 (7.5 s, 30 s, 60 s, and 120 s, respectively), but the adhesive application time was set at 20 s as in the control group (G1). Specimens were then restored with a nanofilled composite material and subjected to microtensile bond strength testing. Bond strength data were statistically analyzed by ANOVA and Tukey’s post-hoc tests (α = 0.05). The relationship of bond strength with etching and adhesive application time was examined using linear regression analysis. Treatment of dentin with halved phosphoric acid etching and adhesive application times (G2) resulted in a significant bond strength decrease compared to the control group (G1) and all other test groups, including the group with halved acid etching, but 20 s of adhesive application time (G6). No significant differences in bond strength were found for groups with multiplied etching times and an adhesive application time of 20 s or more, when compared to the control group (G1). In conclusion, a universal adhesive application time of at least 20 s is recommended when bonding to over-etched dentin.


2007 ◽  
Vol 77 (1) ◽  
pp. 117-124 ◽  
Author(s):  
Güvenç Basaran ◽  
Törün Özer ◽  
Nükhet Berk ◽  
Orhan Hamamcı

Abstract Objective: To test the shear bond strength, surface characteristics, and fracture mode of brackets that are bonded to enamel etched with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser operated at different power outputs: 0.5 W, 1 W, and 2 W. Materials and Methods: Human premolars that had been extracted for orthodontic purposes were used. Enamel was etched with an Er,Cr:YSGG laser system operated at one of three power outputs or with orthophosphoric acid. Results: The shear bond strength associated with the 0.5-W laser irradiation was significantly less than the strengths obtained with the other irradiations. Both the 1-W and 2-W laser irradiations were capable of etching enamel in the same manner. This finding was confirmed by scanning electron microscopy examination. The evaluation of adhesive-remnant-index scores demonstrated no statistically significant difference in bond failure site among the groups, except for the 0.5-W laser–etched group. Generally, more adhesive was left on the enamel surface with laser irradiation than with acid etching. Conclusion: The mean shear bond strength and enamel surface etching obtained with an Er,Cr: YSGG laser (operated at 1 W or 2 W for 15 seconds) is comparable to that obtained with acid etching.


2017 ◽  
Vol 20 (1) ◽  
pp. 17 ◽  
Author(s):  
Beatriz Maria Fonseca ◽  
Daphne Camara Barcellos ◽  
César Rogério Pucci ◽  
Eduardo Bresciani ◽  
Maria Amélia Máximo de Araújo

<p><strong>Objective</strong>: This study evaluated the effect of 0.2% chlorhexidine gluconate solution used as an therapeutic primer on the long-term bond strength of etch-and-rinse adhesive to dentin. <strong>Material</strong> <strong>and</strong> <strong>Methods</strong>: Bovine incisors were worn to expose an area of dentin and were divided into 2 groups: Group C (Control) - acid etching with 37% phosphoric acid + Single Bond; Group CHX (0.2% CHX) - acid etching with 37% phosphoric acid + 0.2% CHX for 30 s + Single Bond. Blocks of composite were fabricated and stored for 24 h or 6 months, sectioned into beams and submitted to microtensile tests. Results were analyzed by two-way ANOVA and Tukey tests. <strong>Results</strong>: Mean (±SD) values (in MPa) were as follow: Group CHX/24h - 41.8(±2.62)A; Group C/24h - 40.8(±3.35)AB; Group CHX/6 months – 36.4(±3.52)B; Group CHX/6 months - 26.1(±1.54)C. <strong>Conclusion</strong>: CHX improve the imediatte bond strength of resin-dentin and significantly lowered the loss of bond strength after 6 months water storage as seen in the control bonds.</p><p><strong>Keywords</strong></p><p>Tensile bond strength; Dentin; Total-etch adhesives; Chlorhexidine gluconate.</p>


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