1. Group A: Five teeth were treated with traditional rotating instruments, the cavities were prepared with diamond drills by turbine, multiple-blade drills by headpiece for removing the decayed dentine and, after cleaning and control of bleeding with cotton pellets with saline solution,RM-GIC (3M ESPE, USA) light-hardening paste was placed gently on the exposed part of the pulp and cavity floor next final restoration with composite z350 flow able and p60 (3M ESPE, USA).

2. Group B : Five teeth cavities were prepared as the same with group one with traditional rotating instruments, hemostatic and cavities sterilization were achieved by a diode 808 nm (Picasso- AMD, USA) laser using following parameters:

• Hemostatic: 1.5 W, CW, fiber diameter 400µm, in contact, 2s per 1mm, vertical and horizontal scanning movement on exposure site.
• Cavity sterilization: 1W, CW, fiber diameter 400µm, in contact, 2mm per s, circular movement.

After hemostatic and cavity sterilization, RM-GIC (3M ESPE, USA) light-hardening paste was placed on the exposed part of the pulp and cavity floor next final restoration with composite z350 flow able and p60 (3M ESPE, USA).

Given low success rate of conventional methods, new techniques as laser-assisted need to be developed.The outcome measure of this study was maintenance of teeth vitality with carious exposed via tertiary dentine formation.the tertiary dentine formation during the time of study was assessed radiological. Therefore vitality of the teeth was depend on dentine formation that was measured periodically in 1,6 and 12 months.