scholarly journals Effect of Er:YAG Laser Irradiation on Shear Bond Strength of Two Porcelain Laminate Veneers Bonded to Tooth Surface

2020 ◽  
Vol 32 (1) ◽  
pp. 21-29
Author(s):  
Ehsan Morshedi ◽  
Maryam Azimi Zavaree ◽  
Seyed Mohammad Reza Hakimaneh ◽  
Sayed Shojaedin Shayegh ◽  
Maryam Pirmoradian ◽  
...  
2019 ◽  
Vol 10 (2) ◽  
pp. 86-91 ◽  
Author(s):  
Rezvaneh Ghazanfari ◽  
Nahal Azimi ◽  
Hanieh Nokhbatolfoghahaei ◽  
Marzieh Alikhasi

Introduction: All-ceramic restorations are being widely used due to its various advantages. However, they have restricted durability and may have to be removed. The conventional procedure for removal is grinding the restoration with rotary instruments which are considered time-consuming and inconvenient. A newer advantageous method is the application of lasers for debonding ceramics from the tooth surface. The objective of this study is to provide a comprehensive literature review on laser-aided ceramic restorations debonding. Methods: We searched PubMed and Google Scholar databases. Seven articles from 2011 to 2018 were identified. Studies were assessed for the efficacy of laser application and the amount of pulpal temperature rise. Results: Studies selected were categorized according to variables including shear bond strength, debonding time and intrapulpal temperature. Oztoprak and Iseri investigated that erbium-doped yttrium, aluminum, and garnet (Er:YAG) laser application reduced shear bond strength of ceramic laminate veneers. The time of debonding took an average of 190 seconds in Rechmann’s study and 106 seconds in Morford’s study. One of the main issues while using the laser is thermal irritation of the pulp. A 5.5°C temperature increase may cause pulpal damage according to Zach and Cohen. Philips et al and Rechmann et al reported no intrapulpal harm due to temperature increase. Additionally, Phillips et al demonstrated that the laser setting affects both the debonding time and the temperature alterations and that a laser adjustment of 2.5 W/25 Hz would be the best safest group. Conclusion: Removal of ceramic crowns and veneers from tooth surfaces can be successfully done by Er:YAG laser application in a less time-consuming procedure and without any harm to the underlying dentin. However, a temperature rise in the pulp may occur which could be overcome by adequate air water cooling.


2013 ◽  
Vol 83 (6) ◽  
pp. 973-980 ◽  
Author(s):  
Serkan Sağır ◽  
Aslıhan Usumez ◽  
Ebru Ademci ◽  
Serdar Usumez

ABSTRACT Objective: To compare the effect of laser irradiation at two different pulse settings and acid etching on the shear bond strength (SBS) of orthodontic brackets to enamel. Materials and Methods: Thirty-six premolars were allocated to three groups (n  =  12): (1) 37% phosphoric acid etching, (2) erbium-doped yttrium aluminum garnet (Er:YAG) laser etching with medium-short pulse mode (MSP; 100 µs, 120 mj, 10 Hz, 1.2 W), and (3) Er:YAG laser etching with quantum-square pulse mode (QSP; 120 mj, 10 Hz, 1.2 W). Metallic brackets were bonded with Transbond XT. After photopolymerization, the samples were subjected to 5000 thermal cycles and debonded with a universal testing machine, and the SBS values were recorded. Surface morphology was evaluated with profilometric examination, scanning electron microscopy, and atomic force microscopy. The adhesive remnant index (ARI) was evaluated to assess the remaining adhesive. Results: The results of SBS testing were analyzed by one-way analysis of variance and Tukey honestly significant diffference tests. The mean SBS values of QSP and MSP laser groups were 11.80 ± 2.7 MPa and 10.10 ± 4.5 MPa, respectively, and the QSP group demonstrated significantly higher SBS (P < .01) than that of the acid-etched group (6.6 ± 2.4 MPa). No significant difference was observed between the SBS values of the two laser groups (P < .05). The difference between the ARI scores of the laser groups and the acid-etched group was statistically significant (P < .05). Conclusion: Laser etching at MSP and QSP modes present successful alternatives to acid etching; however, long-term clinical studies are required to verify clinical success.


2020 ◽  
Vol 25 (1) ◽  
pp. 28-35
Author(s):  
Fernando César Moreira ◽  
Helder Baldi Jacob ◽  
Luis Geraldo Vaz ◽  
Antonio Carlos Guastaldi

ABSTRACT Objective: The purpose of this study was to evaluate the effect of the Yd:YAG laser irradiation on orthodontic bracket base surface. Shear bond strength (SBS) values and sites of the bonding failure interfaces were quantified. Methods: Brackets were divided into two groups: OP (One Piece - integral sandblast base) and OPL (One Piece - laser irradiation). The brackets were randomly bonded on an intact enamel surface of 40 bovine incisors. The SBS tests were carry out using a universal test machine. A stereomicroscopy was used to evaluate the adhesive remnant index (ARI), and surface characterization was performed by scanning electron microscopy (SEM). Student’s t-test was used to compare the SBS between the two groups (p< 0.05). Frequencies and chi-square analysis were applied to evaluate the ARI scores. Results: OPL group showed higher value (p< 0.001) of SBS than OP group (43.95 MPa and 34.81 MPa, respectively). ARI showed significant difference (p< 0.001) between OPL group (ARI 0 = 100%) and OP group (ARI 0 = 15%). SEM showed a higher affinity between the adhesive and the irradiated laser base surface. Conclusions: Yd:YAG laser irradiation on bracket base increased SBS values, showing that bonding failure occurs at the enamel/adhesive interface. Laser-etched bracket base may be used instead of conventional bases in cases where higher adhesion is required, reducing bracket-bonding failure.


2014 ◽  
Vol 25 (6) ◽  
pp. 519-523 ◽  
Author(s):  
Erica Moreno Zanconato-Carvalho ◽  
João Felipe Bruniera ◽  
Natália Spadini de Faria ◽  
Vivian Colucci ◽  
Danielle Cristine Messias

Surface treatment of dentin before the bleaching procedure may affect its permeability and influence the bond strength of restorative materials. This study evaluated the influence of surface treatment before the bleaching on shear bond strength (SBT) of restorative materials to intracoronal dentin. Dentin slabs were subjected to surface treatment: no bleaching (control - CON), no surface treatment + bleaching (HP), 37% phosphoric acid + bleaching (PA) and Er:YAG laser + bleaching (L). After the bleaching procedure, specimens (n=10) were restored with: microhybrid composite resin (MH), flowable composite resin (F), and resin-modified glass-ionomer cement (RMGIC). The shear test was carried out. ANOVA and Tukey's test (α=0.05) showed significant difference for surface treatment and restorative materials (p<0.05). CON presented higher STB and was statistically different from HP (p<0.05). PA and L showed intermediate values and were statistically similar to CON and HP (p>0.05). STB for MH and F were higher than RMGIC (p<0.05), and did not differ from each other (p>0.05). The surface treatments with phosphoric acid and Er:YAG laser before the bleaching procedure provided shear bond strength at the same level of unbleached dentin and the composite resins presented superior bond strength to the intracoronal dentin.


2015 ◽  
Vol 9 (2) ◽  
pp. 69 ◽  
Author(s):  
Farnoosh Alizadeh ◽  
Mohammadreza Malekipour ◽  
Farzaneh Shirani ◽  
Shahram Amini

2011 ◽  
Vol 05 (04) ◽  
pp. 373-379 ◽  
Author(s):  
Subutay Han Altintas ◽  
Onjen Tak ◽  
Asli Secilmis ◽  
Aslihan Usumez

ABSTRACTObjectives: The purpose of this study was to evaluate the effect of three provisional cements and two cleaning techniques on the final bond strength of porcelain laminate veneers. Methods: The occlusal third of the crowns of forty molar teeth were sectioned and embedded in autopolymerizing acrylic resin. Dentin surfaces were polished and specimens were randomly divided into four groups (n=10). Provisional restorations were fabricated and two provisional restorations were cemented onto each tooth. Restorations were fixed with one of three different provisional cements: eugenol-free provisional cement (Cavex), calcium hydroxide (Dycal), and light-cured provisional cement (Tempond Clear). Provisional restorations were removed with either a dental explorer and air-water spray, or a cleaning bur (Opticlean). In the control group, provisional restorations were not used on the surfaces of specimens. IPS Empress 2 ceramic discs were luted with a dual-cured resin cement (Panavia F). Shear bond strength was measured using a universal testing machine. Data were statistically analyzed by ANOVA, Tukey’s HSD and Dunnett tests. Surfaces were examined by scanning electronic microscopy. Results: Significant differences were found between the control group and both the light-cured provisional cement groups and the eugenol-free provisional cement-cleaning bur group (P<.05). Groups that had received light-cured provisional cement showed the lowest bond strength values. Conclusions: Selection of the provisional cement is an important factor in the ultimate bond strength of the final restoration. Calcium hydroxide provisional cement and cleaning with a dental explorer are advisable. (Eur J Dent 2011;5:373-379)


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