STEREOMICROSCOPIC ASPECTS OF ROOT CANAL WALLS AFTER CONVENTIONAL LASER ENDODONTICS – A PRELIMINARY STUDY

Bacterial decontamination of root canals can be improved by directly irradiating the dentinal walls with dental lasers or by irradiating/activating the irrigation solutions, the laser having an indirect clinical action. Inside the root canal, laser irradiation produces a thermal effect on the dentine walls and bacteria, which generates unwanted side effects, if the therapeutic protocol is not followed. The aim of this study was to evaluate the root canal walls by stereomicroscopic ex-amination, after their chemo-mechanical instrumentation and conventional laser irradiation. For this study, 35 palatal roots of upper first molars were used. For some of the palatal canals, con-ventional laser irradiation was performed using a diode laser with a wavelength of 980 nm and two different irradiation protocols. The root canal walls were examined stereomicroscopically at different degrees of magnification. The study demonstrated the effectiveness of the stereomicro-scope in examining the walls of prepared and laser irradiated root canals. Areas of morphological alteration were identified and measured on the walls of the root canals for which the irradiation protocol was not applied correctly

EFFECTS OF OCCLUSAL LOADS IN THE GENESIS OF NON-CARIOUS CERVICAL LESIONS – A FINITE ELEMENT STUDY

Aim of the study This study investigated the magnitude and distribution of stress in a maxillary first premolar subjected to normal and heavy occlusal loads, that were directed vertically and horizontally, using Finite Element Analysis. Material and methods A virtual 3D model of a maxillary first premolar was created using the CT images of a 14 year-old patient and the physical and mechanical properties of the dental tissues used in other studies. We obtained 8 scenarios for the vertical loading and 8 scenarios for the horizontal loading. Results The magnitude and distribution of stress were the least favorable in the case of the heavy horizontal loading applied on the intact tooth. Conclusions Our study showed that the intact tooth was the most affected by stress regardless of the loading applied