1. Micro Vickers hardness and surface roughness of Al-Cu UNS A92124/T851 alloy in relation to turning parameters: an experimental studyVellingiri Sakthivel, Sundara Vadivel G., Arunkumar A., Sivamani S., 2026, izvirni znanstveni članek Ključne besede: Vickers microhardness, surface roughness, UNS A92124/T851, cutting speed, feed rate
Objavljeno v DiRROS: 22.06.2026; Ogledov: 286; Prenosov: 217
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2. The effect of surface roughness on the Er:YAG laser-induced photoacoustic removal of bacteria in zero-gap periodontal/peri-implant pocket modelDominik Šavli, Marko Volk, Katja Molan, Saša Terlep, Špela Levičnik Hoefferle, Aleš Babnik, Mojca Trost, Boris Gašpirc, Matjaž Lukač, David Stopar, Matija Jezeršek, 2025, izvirni znanstveni članek Povzetek: Effective biofilm removal from periodontal and peri-implant pockets remains a challenge due to constrained geometry and limited access. This study investigates a novel phenomenon of distant-field cleaning utilizing Er:YAG laser treatment, where removal of bacteria occurs in areas without previously observed cavitation under high-speed imaging. To understand this effect, we developed a transparent zero-gap model simulating a tooth or implant and surrounding soft tissue. We systematically examined the impact of laser fiber insertion depth, cavitation bubble dynamics, the stiffness and roughness of the material, and laser parameters on the cleaning efficiency. Our findings reveal that the removal of bacteria indeed correlates strongly with cavitation occurrence. Deeper optical fiber insertion into the pocket model only enhanced cleaning efficiency by moving the fluid dynamics and enabling deeper water penetration. Surprisingly, high-speed imaging showed no cavitation in distant regions, raising questions about the mechanisms enabling such cleaning. Further investigation uncovered that surface roughness played a critical role in facilitating this distant-field effect. The smooth, transparent surfaces used in imaging experiments suppressed fluid dynamics, while textured surfaces created by 3D-printed molds and bacterial monolayer allowed deeper water penetration and pressure wave propagation. These surface irregularities enabled localized cavitation events and enhanced bacterial disruption, even in regions beyond the laser fiber’s immediate influence. This study emphasizes the significance of surface roughness in test models, highlighting the need for models to closely mimic the conditions of real clinical scenarios for accurate optimization of Er:YAG laser-induced photoacoustic removal of bacteria.
Ključne besede: Er:YAG laser, cavitation dynamics, biofilm removal, surface roughness, photoacoustic cleaning, periodontal and peri-implant pockets, secondary cavitation
Objavljeno v DiRROS: 20.04.2026; Ogledov: 298; Prenosov: 324
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3. Effect of Ti and S content on the properties and machinability of low-carbon ferritic–pearlitic steelBoštjan Arh, Franc Tehovnik, Franci Vode, Bojan Podgornik, 2024, izvirni znanstveni članek Povzetek: This research was focused on the effect of Ti and S content on the formation of non-metallic inclusions and their influence on the mechanical properties and machinability of low-carbon ferritic– pearlitic steels. An analysis and classification of the non-metallic inclusions were carried out. The tensile strength and impact toughness were determined from samples taken in the rolling direction. Machinability investigations were carried out on a CNC turning machine and by analyzing the surface roughness. TiO-TiN inclusions are present in steels with an increased Ti content. In these steels, the hardness, tensile strength, and cutting forces increase with a higher proportion of Ti. In the second group of steels with increased contents of S, Al, and Ca, MnS and CaO-Al2O3-MnS non-metallic inclusions are formed. As the S content increases, the tensile strength and cutting forces decrease, while the impact toughness increases. In steels with added Ti, the This research was focused on the effect of Ti and S content on the formation of non-metallic inclusions and their influence on the mechanical properties and machinability of low-carbon ferritic– pearlitic steels. An analysis and classification of the non-metallic inclusions were carried out. The tensile strength and impact toughness were determined from samples taken in the rolling direction. Machinability investigations were carried out on a CNC turning machine and by analyzing the surface roughness. TiO-TiN inclusions are present in steels with an increased Ti content. In these steels, the hardness, tensile strength, and cutting forces increase with a higher proportion of Ti. In the second group of steels with increased contents of S, Al, and Ca, MnS and CaO-Al2O3-MnS non-metallic inclusions are formed. As the S content increases, the tensile strength and cutting forces decrease, while the impact toughness increases. In steels with added Ti, the machining is more difficult, but a finer surface is achieved after turning, while a higher S content results in an increased fraction of softer sulfide inclusions, which reduce the cutting forces but also result in a reduced surface quality. turning, while a higher S content results in an increased fraction of softer sulfide inclusions, which reduce the cutting forces but also result in a reduced surface quality.
Ključne besede: non-metallic inclusions, mechanical properties, machinability, surface roughness
Objavljeno v DiRROS: 03.09.2024; Ogledov: 1537; Prenosov: 1443
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4. The impact of Al2O3 particles from grit-blasted Ti6Al7Nb (alloy) implant surfaces on biocompatibility, aseptic loosening, and infectionBoštjan Kocjančič, Klemen Avsec, Barbara Šetina, Darja Feizpour, Matjaž Godec, Veronika Kralj-Iglič, Rok Podlipec, Andrej Cör, Mojca Debeljak, John T. Grant, Monika Jenko, Drago Dolinar, 2023, izvirni znanstveni članek Ključne besede: Ti6Al7Nb implant alloy cementless hip endoprostheses, roughness, Al2O3 grit blasting, surface and subsurface implant contamination, cytotoxicity, aseptic loosening, infection, osseointegration
Objavljeno v DiRROS: 01.02.2024; Ogledov: 2027; Prenosov: 1307
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