MICROSCOPE EVALUATION OF MICRO-GAPS AT IMPLANT-ABUTMENT CONNECTION

The use of custom CAD/CAM abutments in implant restorations has become a reality, but there are questions about the existence of micro-gaps at the implant-abutment junction larger than those of the original standard stock abutments. The purpose of this study was to compare dimensions of the micro-gaps between four types of implant abutments (original dental implant stock abutments, compatible dental implant stock abutments, and two types of customized CAD/CAM dental implant abutments) all with the same connection of Bredent Sky system mounted on a standard implant. Material and Method: Micro-gap measurements were made on four groups of Titanium abutments: 1) original dental implant stock abutments – industrial machined, 2) compatible dental implant stock abutments – industrial machined and 3) and 4) compatible customized CAD/CAM dental implant abutments – non-industrial milled with two different parameters in hyperDENT CAM software and Paragon Tools. The Nikon SMZ745T stereomicroscope was used to measure the micro-gaps of each dental implant abutment and results were statistically analyzed. Results: The micro-gaps measured on implant-abutments junction did not show significant differences between original abutment, and the three types of compatible abutments. Conclusions: No significant differences of the micro-gap at the implant-abutment junction were observed between the original implant abutments and compatible abutments, and customized abutments. Micro-gap dimensions were within the clinically accepted limit and the use of custom CAD/CAM dental implant abutments is reliable

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

A DIGITAL APPROACH FOR THE ANALYSIS OF THE OPTICAL COHERENCE TOMOGRAPHY EVALUATION OF HYDROXYAPATITE – BASED BONE GRAFT MATERIALS

The aim of this study was to evaluate by means of coherence optical tomography (OCT) two synthetic bone augmentation materials based on hydroxyapatite and to quantify the degree of filling of the experimental cavities created one month and two months after their creation. We made 4 groups of 5 Whistar rats on which we created experimental cavities in calvaria and in the upper maxillary. Samples were obtained after one months for two study group and after two months for the other two. After obtaining the images from the optical coherence tomography examination, they were analysed with the ImageJ software. The results provided important information related to the healing pattern of the experimental cavities, the degree of their filling with newly formed bone tissue, but also about the presence of residual particles of synthetic bone graft materials.The increased refractive index of a synthetic bone augmentation material is an important advantage in assessing by OCT the presence of material particles in a bone cavity. The maxillary bone anatomy due to its convexities made more difficult the evaluation of the samples from this area compared to the flat surfaces offered by the calvaria samples. Optical coherence tomography remains a promising method for the evaluation of new-forming bone tissue when synthetic bone graft materials are used, both for research evaluation in order to compare different materials, but also for the potential to be used in clinical activity as well