Comparative microleakage outcomes of different techniques used for creating the occlusal anatomy in occlusal direct restorations using the dental operating microscope.

OBJECTIVES: Microleakage in direct dental restorations is a primary causal factor in the restoration's failure. The aim of this study was to evaluate whether the technique for occlusal layering of the composite resin (the use of brush adaptation, the use of magnification, cusp build-up, stamp technique) has any effect on microleakage of direct restorations in occlusal cavities. MATERIALS AND METHODS: One hundred extracted human molars were restored using five restoration techniques (Packable Bulk technique, Occlusal Stamp technique, Successive Cusp Build-up technique, Successive Cusp Build-up technique + Brush adaptation, Successive Cusp Build-up technique + brush adaptation + Dental Operative Microscope magnification). The teeth were subjected to thermal aging for 800 cycles at 5°C and 55°C, infiltrated with basic fuchsin dye for 24 h, and then sectioned buccolingually in the middle of the crown. Infiltration was measured in four areas of the tooth section by five different observers and then given a score from 1 to 3, proportional to infiltration depth. RESULTS: The lowest mean scores for infiltration (meaning less infiltration observed) were present in Group A (1.41 ± 0.878) and Group C (1.46 ± 0.679), while Group D showed the highest infiltration scores (1.75 ± 0.853). When comparing the groups for differences, no statistically significant difference in infiltration was found between any technique p < .586. CONCLUSION: The techniques examined for placing the occlusal layer of composite in direct restorations do not differ significantly in terms of marginal infiltration, although a slight improvement was found when using the bulk technique and the successive cusp build-up.

Comparative analysis of preclinical dental students' working postures using dental loupes and dental operating microscope.

BACKGROUND: Dentists are susceptible to musculoskeletal disorders due to prolonged static postures during dental treatments. Using a magnification tool like dental operating microscope (DOM) or the dental loupes may correct the operator's posture. Up until now, few studies have focused on preclinical dental students' posture when working with the DOM, while most of them have focused on the loupes. The aim of this study was to comparatively analyse the working posture of preclinical students during a dental restoration procedure, working with two different magnification methods. MATERIALS AND METHODS: This study used a randomised cross-over design in which seventeen third year students were randomly divided into three groups. The exclusion criteria were previous contact with magnification systems and previous clinical working experience. Each student prepared 3 Black class 1 cavities on artificial lower molars: first with no magnification, following dental loupes and DOM. They were video-recorded throughout the preparation. Trunk, neck and upper-arm position were evaluated using the Posture Assessment Instrument. Students completed a questionnaire on their subjective perception of the two magnification systems. RESULTS: The statistical analysis showed significant improvement of the working posture using magnification systems compared to direct vision. The biggest improvement was obtained through the use of DOM, followed by the dental loupes. Students perceived dental loupes as being the most comfortable and easy to adapt to. They reported being more focused when using DOM. CONCLUSIONS: Both magnification systems had a positive impact on the working posture, DOM having the best results. Loupes showed better adaptability while DOM showed better concentration.