Effects of femtosecond laser and other surface treatments on the bond strength of metallic and ceramic orthodontic brackets to zirconia

Abstract

Femtosecond laser has been proposed as a method for conditioning zirconia surfaces to boost bond strength. However, metallic or ceramic bracket bonding to femtosecond laser-treated zirconia surfaces has not been tested. This study compared the effects of four conditioning techniques, including femtosecond laser irradiation, on shear bond strength (SBS) of metallic and ceramic brackets to zirconia.Three hundred zirconia plates were divided into five groups: 1) control (C); 2) sandblasting (APA); 3) silica coating and silane (SC); 4) femtosecond laser (FS); 5) sandblasting followed by femtosecond laser (APA+SC). A thermal imaging camera measured temperature changes in the zirconia during irradiation. Each group was divided into 2 subgroups (metallic vs ceramic brackets). SBS was evaluated using a universal testing machine. The adhesive remnant index (ARI) was registered and surfaces were observed under SEM. Surface treatment and bracket type significantly affected the bracket-zirconia bond strength. SBS was significantly higher (p<0.001) for ceramic brackets in all groups (APA+FS > APA > FS > SC > control) than metallic brackets (APA+FS > FS > SC > APA > control). For metallic brackets, groups SC (5.99 ± 1.86 MPa), FS (6.72 ± 2.30 MPa) and APA+FS (7.22 ± 2.73 MPa) reported significantly higher bond strengths than other groups (p < 0.05). For ceramic brackets, the highest bond strength values were obtained in groups APA (25.01 ± 4.45 MPa), FS (23.18 ± 6.51 MPa) and APA+FS (29.22 ± 8.20 MPa).Femtosecond laser enhances bond strength of ceramic and metallic brackets to zirconia. Ceramic brackets provide significantly stronger adhesion than metallic brackets regardless of the surface treatment method.

Effect of Fiber Laser Irradiation on the Shear Bond Strength between Acrylic Resin and Titanium

“…Fiber lasers exhibit some important advantages over previous technologies with regard to source brilliance, oscillating mode stability, efficiency, possibility of monolithic packaging, and low maintenance costs [22, 23]. Fiber lasers quickly and powerfully affect surfaces while causing less mechanical and thermal damage compared to other lasers [22–25]. Ultrafast fiber lasers are mainly used in dentistry to modify the surface of implants [22, 26, 27].…”

“…Since laser parameters have the capability to influence and alter the surface microstructure, lasers may be an alternative method for surface treatment for the purpose of enhancing the bond between various materials [23]. One study showed that a femtosecond laser application increased the bond between both ceramic and metal brackets and zirconium oxide [25]. Ates et al [18] reported that ultrafast fiber laser applications increased the bond strength between resin cement and titanium and that ultrafast fiber lasers may be an alternative method for roughening metal surfaces.…”

Effect of fiber laser application on titanium surface on bonding strength of resin cement

“…Fiber lazerler iyi bir ışın kalitesine sahiptir ve metal yüzeylerden kolayca emilir, ayrıca kısa atım uzunlukları nedeniyle ısıl etki olmadan yüzey işlemi sağlamaktadır. 30,[54][55][56] Bu lazer, ablasyon soğutmayı mümkün kılan, gerekli ablasyon için lazer darbe enerjilerini azaltan ve yüzeyden malzeme kaldırma işleminin etkinliğini artıran son derece yüksek tekrarlama oranlarına sahiptir. 30,54,55 Bu avantajları fiber lazerlerin son yıllarda materyal yüzeylerinin işlenmesinde sıklıkla tercih edilmelerini sağlamıştır.…”

“…30,[54][55][56] Bu lazer, ablasyon soğutmayı mümkün kılan, gerekli ablasyon için lazer darbe enerjilerini azaltan ve yüzeyden malzeme kaldırma işleminin etkinliğini artıran son derece yüksek tekrarlama oranlarına sahiptir. 30,54,55 Bu avantajları fiber lazerlerin son yıllarda materyal yüzeylerinin işlenmesinde sıklıkla tercih edilmelerini sağlamıştır. 30,51,56,57 Ancak, diş hekimliğinde kullanımları ile ilgili çalışmalar sınırlıdır.…”

Femtosecond laser microstructuring of alumina toughened zirconia for surface functionalization of dental implants

“…Femtosecond laser machining has already been proposed as an innovative technique to create topographical features on the surface of ceramics, commonly used in the fields of optical and refractory materials. Some studies have reported the use of femtosecond laser to texture the surface of hard ceramics [19][20][21], although little work has been conducted on periodic surface structuring, particularly with the intent of implants development, with scarce results available on the biological response to these materials [22][23][24][25].…”