Effects of Er:YAG laser pre-treatment on dentin structure and bonding strength of primary teeth: an in vitro study

BMC Oral Health

Kuan Yang¹  Zhi fei Zhou²  Xin Ge³  Yu jiang Chen³  Lu lu Wang³  Xiao jing Wang³  Bai ze Zhang³  Jun hui Wang³  Zi rui Wang³ 

[1] Department of Orthodontics, College of Stomatology, Xi’an Jiaotong University, No. 98, Xiwu Road, Xincheng District, Xi’an, Shaanxi, China;Department of Stomatology, General Hospital of Tibet Military Region, Chinese People’s Liberation Army, Lhasa, Tibet, China;State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Disease and Shaanxi Clinical Research Center for Oral Diseases, Stomatology Department of Children, School of Stomatology, The Fourth Military Medical University, No. 145, Changle West Road, Xincheng District, Xi’an, Shaanxi, China;

关键词: Er:YAG laser;    Primary teeth;    Dentin tubules;    Peritubular dentin;    Shear bond strength;    Dentin tablets;   

DOI  :  10.1186/s12903-020-01315-z

来源: Springer

【 摘 要 】

BackgroundTo investigate the effects of Er:YAG laser pre-treatment on the dentin structure and shear bond strength of primary teeth.MethodsDentin specimens were prepared using freshly extracted intact primary molars and divided randomly into four groups based on the surface treatment applied. The control and etchant groups received no treatment and conventional acid etching treatment, respectively, while the energy and frequency groups received laser surface treatment with variable energy (50–300 mJ) and frequency (5–30 Hz) parameters. The morphology was observed using scanning electron microscopy. The surface-treated dentin slices were bonded to resin tablets, followed by thermocycle treatment. The shear strength was determined using a universal testing machine and de-bonded surfaces were observed using a stereomicroscope.ResultsSEM observation showed that the surface morphology of the dentin slices changed after etching as well as after Er:YAG laser pre-treatment with different energy and frequency values. The dentin tubules opened within a specific energy (50–200 mJ) and frequency (5–20 Hz) range. Beyond this range, the intertubular dentin showed cracks and structural disintegration. Shear strength tests showed no significant changes after acid etching. The shear strength increased significantly (P < 0.05) after Er:YAG laser pre-treatment compared with that of the control group. The shear strength increased within the same energy (50–200 mJ) and frequency (5–20 Hz) range as the tubule opening, but not significantly (P > 0.05). The most common mode of interface failure was adhesive (interface) failure, followed by mixed and resin cohesive failure.ConclusionsPre-treatment using Er:YAG laser opens the dentinal tubules without the formation of a smear layer and improves the bonding strength between the primary teeth dentin and the resin composites.

【 授权许可】

CC BY