Probing depth in periodontal pockets: In vitro evaluation of contributions to variability due to probe type and operator skill.

Periodontal probing aims at detecting the presence, type and gravity of periodontal diseases influencing distance between gingival margin and connective ligament. Measurements in vivo are affected by substantial uncertainty, owing, for example, to probe features, anatomic variations and operator's skill. Inadequate reproducibility in periodontal probing may lead to diagnostic mistakes and inappropriate therapeutic decisions. In vitro evaluation of reproducibility of measurements of periodontal pockets was aimed at while developing a Periodontal Calibration Box designed to calibrate periodontal probe operators, catering also for simulating contraction observed in vivo. Probe type and clinical experience of operators were found to affect substantially probing errors.

Microbial biofilm modulation by ultrasound: current concepts and controversies.

Biofilm elimination is often necessary during antimicrobial therapy or industrial medical manufacturing decontamination. In this context, ultrasound treatment has been frequently described in the literature for its antibiofilm effectiveness, but at the same time, various authors have described ultrasound as a formidable enhancer of bacterial viability. This discrepancy has found no solution in the current literature for around 9 years; some works have shown that every time bacteria are exposed to an ultrasonic field, both destruction and stimulation phenomena co-exist. This co-existence proves to have different final effects based on various factors such as: ultrasound frequency and intensity, the bacterial species involved, the material used for ultrasound diffusion, the presence of cavitation effects and the forms of bacterial planktonic or biofilm. The aim of this work is to analyze current concepts regarding ultrasound effect on prokaryotic cells, and in particular ultrasound activity on bacterial biofilm.

Subjective and objective speech intelligibility investigations in primary school classrooms.

This work concerns speech intelligibility tests and measurements in three primary schools in Italy, one of which was conducted before and after an acoustical treatment. Speech intelligibility scores (IS) with different reverberation times (RT) and types of noise were obtained using diagnostic rhyme tests on 983 pupils from grades 2-5 (nominally 7-10 year olds), and these scores were then correlated with the Speech Transmission Index (STI). The grade 2 pupils understood fewer words in the lower STI range than the pupils in the higher grades, whereas an IS of ~97% was achieved by all the grades with a STI of 0.9. In the presence of traffic noise, which resulted the most interfering noise, a decrease in RT from 1.6 to 0.4 s determined an IS increase on equal A-weighted speech-to-noise level difference, S/N(A), which varied from 13% to 6%, over the S/N(A) range of -15 to +6 dB, respectively. In the case of babble noise, whose source was located in the middle of the classroom, the same decrease in reverberation time leads to a negligible variation in IS over a similar S/N(A) range.