Symmetry of non-carious cervical lesions in canines and premolars.

Objectives: Clinically non-carious cervical lesions (NCCLs) are frequently seen. The aim of this study was to investigate the relationship between the shape and symmetry of NCCLs, wear of cuSPS and triangular ridge, and the curvature of the tooth root.

Methods: One hundred and twenty-nine extracted human upper canine teeth and 274 extracted human upper premolar teeth with NCCLs were used in this study.

Application of DIAGNOdent as a guide for removing carious dentin with Er:YAG laser.

Objectives: The purpose of this study was to investigate the DIAGNOdent values applicable as a guide for removal of outer layer of carious dentin with Er:YAG laser.

Methods: Carious dentin of human extracted molars was removed by bur with Caries Detector (Group 1: red stained dentin was left, Group 2: light pink stained dentin was left) and by Er:YAG laser with DIAGNOdent value as a guide (30>Group 3>21, 20>Group 4>11, 10>Group 5). The cavity floor dentin after removing carious dentin was examined using microradiograms, EPMA and SEM.

Output energy changes of quartz contact probe for Er:YAG laser with tooth ablation.

The purpose of this study was to examine the output energy changes of the contact probe for Er:YAG laser with tooth ablation and evaluate the effect of contact surface polishing on output energy. The Er:YAG laser was irradiated to enamel of extracted human incisors for 100 min (5 min x 20 times). The output energy of contact probes was measured every 5 min (n = 3).

Electron probe micro-analysis of a contact probe after Er:YAG laser tooth ablation.

The purpose of this study was to investigate the contact probes of Er:YAG laser before and after tooth ablation. Three kinds of contact probe were prepared. The first was an unused probe (NE).

Effects of Er:YAG laser irradiation on human dentin: polarizing microscopic, light microscopic and microradiographic observations, and FT-IR analysis.

Background And Objectives: The effects of Er:YAG laser irradiation on dentin have not been sufficiently investigated. The purpose of this study was to investigate the effects of Er:YAG laser irradiation on dentin.

Study Design/materials And Methods: After cavities were prepared using Er:YAG laser irradiation or rotary cutting instruments, histological observations of cavity-floor dentin utilizing polarizing microscopy, microradiography and light microscopy, and analysis of composition of cavity-floor dentin using Fourier-transformed (FT-IR) spectrometry were conducted.

Comparison of the bond strength of composite resin to Er:YAG laser irradiated human enamel pre-treated with various methods in vitro.

Background And Objective: We have reported that the application of ultrasonic scalers on the Er:YAG laser-irradiated enamel surface achieved bond strengths of approximately 16 MPa. However, it is reported that a bond strength of 20 MPa is needed to prevent the marginal gaps, so the tensile bond strength (TBS) of composite resin to the Er:YAG laser-irradiated enamel is still insufficient.

Study Design/materials And Methods: Various methods (phosphoric acid etching, air scaling, ultrasonic scaling, air powder polishing, combination with phosphoric acid etching, and prior mechanical removal methods) were tested as a technique to increase TBS of composite resins to the Er:YAG irradiated enamel.

Adhesion of Er:YAG laser-irradiated dentin and composite resins: application of various treatments on irradiated surface.

Background And Objectives: The investigation of adhesion between an Er:YAG laser-irradiated surface and composite resin is very important to ensure the best clinical results. The purpose of this investigation is to determine if the application of various treatments on Er:YAG laser-irradiated dentin surface affects the tensile bond strength between dentin and composite resins.

Study Design/materials And Methods: In this investigation, the application of phosphoric acid, ultrasonic scaler, air-scaler, and air-powder polisher were tested as techniques to increase the bond strength of composite resins to Er:YAG laser-irradiated dentin surface.