Microbiome Changes After Laser and Chlorhexidine Disinfection in Caries Removal

Each CHX cavity will be treated with disinfectant with a disposable micro brush tip and left undisturbed for 20 seconds. They will then be air-dried for 10 seconds and restore the tooth.

After the caries removal procedure, the cavity will be disinfected using an Er,Cr: YSGG laser (EPIC X™, BIOLASE, USA) with 940 nm and 0.1 W output power. The laser tip will be a 400 µm tip with an energy density of 138.12 J/cm in non-contact mode (2 mm distance), 5 s/mm2 sweeping motion.

Carious tissue will be completely removed from the surrounding cavity walls with a tungsten carbide bur, leaving at least 2 mm of peripheral intact tooth structure for good adaptation and sealing of the restoration.

Access to the lesion will be achieved using a high-speed handpiece with a sterile high-speed bur. The polymer bur will be used with a low-speed handpiece at 5,000-10,000 RPM to remove carious dentin in sizes RA4, RA6, and RA8 according to the size of the caries lesion. The instrument will be used with a circular, light force starting from the center of the carious lesion towards the periphery as recommended by the manufacturer. Caries removal will be stopped when the instrument is macroscopically worn and blunt and can no longer remove tissue. An excavator will be used to verify if any caries remain at the base of the cavity. If necessary, a new polymer bur will be used to remove the remaining decay.