Effect of CPP-ACP paste with and without CO2 laser irradiation on demineralized enamel microhardness and bracket shear bond strength

Abstract

Introduction: Many patients seeking orthodontic treatment already have incipient enamel lesions and should be placed under preventive treatments. The aim of this in vitro study was to evaluate the effect of CPP-ACP paste and CO2 laser irradiation on demineralized enamel microhardness and shear bond strength of orthodontic brackets. Methods: Eighty caries-free human premolars were subjected to a demineralization challenge using Streptococcus mutans. After demineralization, the samples were randomly divided into five equal experimental groups: Group 1 (control), the brackets were bonded without any surface treatment; Group 2, the enamel surfaces were treated with CPP-ACP paste for 4 minutes before bonding; Group 3, the teeth were irradiated with CO2 laser beams at a wavelength of 10.6 µm for 20 seconds. The samples in Groups 4 and 5 were treated with CO2 laser either before or through CPP-ACP application. SEM photomicrographs of a tooth from each group were taken to observe the enamel surface. The brackets were bonded to the buccal enamel using a conventional method. Shear bond strength of brackets and ARI scores were measured. Vickers microhardness was measured on the non-bonded enamel surface. Data were analyzed with ANOVA and Tukey test at the p< 0.05 level. Results: The mean shear bond strength and microhardness of the laser group were higher than those in the control group and this difference was statistically significant (p< 0.05). All groups showed a higher percentage of ARI score 4. Conclusion: CO2 laser at a wavelength of 10.6 µm significantly increased demineralized enamel microhardness and enhanced bonding to demineralized enamel.

The Effect of the Er:YAG Laser and MI Paste Plus on the Treatment of White Spot Lesions

“…Many other studies have also used this test to measure the remineralization changes. 26,27,31,34 The findings of the present study were in contrast with those of Heravi et al indicating that the use of the erbium laser alone and in combination with CPP-ACPF was not effective in the treatment of WSLs. 26 These differing results may be due to the difference in various parameters of lasers used such as pulse energy, pulse duration, energy density, radiation time, and use of or not use of air or water for cooling during laser irradiation.…”

The Effect of Remineralizing Agents With/Without CO2 Laser Irradiation on Structural and Mechanical Properties of Enamel and its Shear Bond Strength to Orthodontic Brackets

“…51 Despite the higher microhardness values obtained in the laser groups, the differences were not significant. As a result, the synergistic effect of the laser with the remineralizing agents was not evident in our findings, which is similar to the findings from the study by Farhadian et al 52 Melting and recrystallization of the enamel surface may explain higher microhardness values and also the higher intensity of HA peaks for the laser groups. Contrary to our findings, Khamverdi et al and Niyazi et al showed a synergistic effect of the CO 2 laser with CPP-ACP on improving the enamel microhardness, which confirms the facilitating role of lasers in the penetration of remineralizing agents into deeper layers of HA.…”

Current Overview of Remineralization Materials and Technologies

“…Lazer kullanımının mineralizasyonu hızlandırdığı, aynı zamanda kristal büyümesini de kontrol edebileceği düşünülmektedir. 67,69 Topikal florür tedavisi ile birleştirilen lazer ışınlamasının, florür alımını arttıran ve minenin çözünme oranını tek başına lazer veya florür uygulamasına kıyasla önemli ölçüde azaltan sinerjistik bir etki yarattığı gösteren çalışmalar olduğu gibi lazer uygulamasının belirgin remineralizasyon etkisinin olmadığı ve florun etkisini arttırmadığını da bulgulayan çalışmalar da mevcuttur. [70][71][72] Ayrıca çeşitli lazer türlerinin CPP-ACP içeren remineralizasyon materyalleri ile birlikte kullanımı ile ilgili araştırmalar da yapılmıştır.…”

“…Bazı araştırmacılar lazerin demineralize mine yüzeyindeki CPP-ACP'nin remineralizasyon etkisini arttırdığını bildirse de bazı çalışma sonuçlarına göre lazer ve CCP-ACP'nin birlikte kullanılmasının sinerjistik bir remineralizasyon etkisinin olmadığı gözlemlenmiştir. 69,73 Lazerlerin tek başına ya da remineralizasyon materyalleri ile birlikte kullanımını değerlendiren birçok çalışma yapılmış olsa da sonuçlar çelişkilidir ve etkinliğinin kanıtlanabilmesi için daha fazla klinik araştırma yapılmasına ihtiyaç vardır.…”