Roya Naseh; Nima Rahnamoon; Maryam Afshari
Abstract
Background: Assure Universal Bonding Resin is capable of providing a strong bond between orthodontic attachments and amalgam surfaces.
Objectives: This study sought to assess the shear bond strength of orthodontic attachments to amalgam surfaces using Assure Universal Bonding Resin after different surface ...
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Background: Assure Universal Bonding Resin is capable of providing a strong bond between orthodontic attachments and amalgam surfaces.
Objectives: This study sought to assess the shear bond strength of orthodontic attachments to amalgam surfaces using Assure Universal Bonding Resin after different surface treatments.
Methods: This in-vitro experimental study was conducted on 120 amalgam samples in eight groups of surface roughening with diamond bur, sandblasting with aluminum oxide particles, Er, Cr: YSGG laser irradiation and polishing-only. Molar buccal tubes were bonded to amalgam surfaces using Assure primer and Transbond Plus light-cure composite. Half the samples were immediately subjected to shear bond strength testing while the remaining half were incubated at 37°C for one week, thermocycled (1000 cycles) and were then subjected to shear bond strength test. One-way ANOVA was applied to compare the bond strength of the groups and Tukey’s test was used for pairwise comparisons. The adhesive remnant index (ARI; 4 point-scale) was also determined in the groups and the results were analyzed using the Kruskal-Wallis test. Results: Significant differences were noted in shear bond strength of attachments following the application of Assure among different surface treatment modalities (P < 0.001); the highest bond strength was noted in sandblasted group followed by laser, bur and polishing, respectively. Aging had no significant effect on bond strength.
Conclusions: Sandblasting and irradiation of Er, Cr: YSGG laser provided sufficiently high bond strength between amalgam and attachments following the application of Assure. Diamond bur and polishing did not provide adequately high bond strength.
Mohammad Hosein Ahangar Atashi; Reza Fekrazad; Leila Ebrabimpour
Abstract
Aim: The demineralization of enamel adjacent to orthodontic brackets is a clinical problem which can lead to some esthetic concerns after the treatment. The present study investigated the effect of laser, fluoride and combination of two techniques on the demineralization of enamel adjacent to orthodontic ...
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Aim: The demineralization of enamel adjacent to orthodontic brackets is a clinical problem which can lead to some esthetic concerns after the treatment. The present study investigated the effect of laser, fluoride and combination of two techniques on the demineralization of enamel adjacent to orthodontic brackets.Materials and Methods: In this in vitro study, 60 healthy human premolars were selected and the brackets were bonded to them. The specimens were randomly assigned to 4 groups (n=15): topical APF application, laser irradiation, Laser + fluoride and control specimens. Er,Cr:YSGG laser was irradiated at 12.5 mJ/cm2 pulse energy without water spray While APF gel was applied on the specimen surfaces for 4 minutes. All specimens were demineralized for 10 days in a 0.2M acetate buffer solution and the calcium content were subsequently determined with atomic absorption spectrometery. The data were subjected to analysis of variance and Tukey post hoc test.Results: The mean calcium content of specimens with APF fluoride application was 6.52±1.241 PPM, in laser was 6.66±0.64 PPM, in laser + fluoride specimens was 6.21±0.77 PPM and in control ones was 7.09±0.56 PPM, The calcium content of specimens subjected to laser irradiation and fluoride was significantly lower than control specimens (p=0.029), while no other significant differences were noted in the next comparisons.Conclusion: Er,Cr:YSGG laser irradiation does not increase acid resistance of enamel around orthodontic brackets with mentioned parameters, so, it is not recommended for clinical usage. Although, fluoride application following laser irradiation significantly increased acid resistance of specimens compared to control.
