Saeid Sadeghian; Meysam Mahabadi; H. Saadat Hosseini; B. Sabagh
Abstract
Background and aim: Laser ablation as an alternative method for etching porcelain has been proposed. However,previous studies have reported contrasting results. This study is designed to investigate techniques that could obtain maximum bond strength and also modes of their fracture.Materials and method: ...
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Background and aim: Laser ablation as an alternative method for etching porcelain has been proposed. However,previous studies have reported contrasting results. This study is designed to investigate techniques that could obtain maximum bond strength and also modes of their fracture.Materials and method: Fifty samples of porcelain fused to metal according to surface preparation were divided into five groups: 1.HF acid(9.6%) 2. HF acid+ silane 3. Co2 laser (2w, 30 s) 4. Co2 laser+silane 5.removing the glazed layer with diamond bur (controls). After bonding orthodontic brackets and thermocycling process, the shear bond strength (SBS) measured with Instron. Results analyzed by one way ANOVA and Least Significant Difference (p < 0.001). pattern of debonding was investigated with light microscope and results were analyzed by Kruskall wallis and Mann-whitney (p < 0.001).Results: results showed bond strength of Co2 laser (2 w) was clinically high although it was lower than HF acid samples, with better mode of fracture.Conclusion: HF acid in combination with silane showed the highest shear bond strength value while irradiation of grouped pulse Co2 laser for 30 s in combination with silane could be an alternative for HF acid etching.
Nasrin Farhadian; Amirfarhang Miresmaeili; Loghman Rezaei Soufi; Fahimeh Baghaei; Ehsan Shahvali
Abstract
Aim: of this in vitro study was to evaluate the effects of Co2 laser irradiation on demineralization adjacent to orthodontic brackets and their shear bond strength in human premolar teeth. Enamel demineralization adjacent to orthodontic brackets is a major problem that requires new professional method ...
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Aim: of this in vitro study was to evaluate the effects of Co2 laser irradiation on demineralization adjacent to orthodontic brackets and their shear bond strength in human premolar teeth. Enamel demineralization adjacent to orthodontic brackets is a major problem that requires new professional method independent to patient cooperation.
Materials and methods: Sixty human premolars were randomly divided to two groups (n=30). Group1, enamel surface irradiated with Co2 laser. Group2 without any enamel surface treatment. In both groups, a bracket at buccal surface was bonded with Transbond XT and cured with conventional light cure. Demineralization in all sample induced with artificial caries solutions. A universal testing machine was used to determine shear bond strengths. The teeth were sectioned bucco-lingually and were evaluated under polarized light microscope. Average lesion depths were calculated from three depth measurements. The Two independent sample T- tests were used to compare the study type group in detail.
Results: The mean of shear bond strengths in the group1 and 2 were 13.90±5.01and 15.84 ±3.68 Mpa respectively, but not statistically significant (P=0.102).The mean lesion depth in group1and 2 was 72.29±58.09 µm 120.01±76.49µm respectively, which was significant (P=0.018). Conclusion: Co2 laser irradiation can reduce enamel demineralization while not affecting the shear bond strengths significantly.
Nasrin Farhadian; Amirfarhang Miresmaeili; Loghman Rezaei Soufi; Fahimeh Baghaei; Ehsan Shahvali
Abstract
Aim: of this in vitro study was to evaluate the effects of Co2 laser irradiation on demineralization adjacent to orthodontic brackets and their shear bond strength in human premolar teeth. Enamel demineralization adjacent to orthodontic brackets is a major problem that requires new professional method ...
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Aim: of this in vitro study was to evaluate the effects of Co2 laser irradiation on demineralization adjacent to orthodontic brackets and their shear bond strength in human premolar teeth. Enamel demineralization adjacent to orthodontic brackets is a major problem that requires new professional method independent to patient cooperation.Materials and methods: Sixty human premolars were randomly divided to two groups (n=30). Group1, enamel surface irradiated with Co2 laser. Group2 without any enamel surface treatment. In both groups, a bracket at buccal surface was bonded with Transbond XT and cured with conventional light cure. Demineralization in all sample induced with artificial caries solutions. A universal testing machine was used to determine shear bond strengths. The teeth were sectioned bucco-lingually and were evaluated under polarized light microscope. Average lesion depths were calculated from three depth measurements. The Two independent sample T- tests were used to compare the study type group in detail.
Results: The mean of shear bond strengths in the group1 and 2 were 13.90±5.01and 15.84 ±3.68 Mpa respectively, but not statistically significant (P=0.102).The mean lesion depth in group1and 2 was 72.29±58.09 µm 120.01±76.49µm respectively, which was significant (P=0.018).Conclusion: Co2 laser irradiation can reduce enamel demineralization while not affecting the shear bond strengths significantly.