Purpose: . The purpose of this study is to analyze the biomechanical differences in rotation angle-torque according to the type of implant and to compare the effects of contamination and sandblasting on the removal torque value (RTV) of abutment screws. Materials and methods: . For this study, an automated device for tightening and loosening implant screws was developed, and each 15 implant-abutment complexes of external and internal connection type were prepared, divided into three groups according to the surface treatment of the screw:control group (no treatment), experimental group-1 (artificial saliva contamination and chlorhexidine (CHX) rinsing), and experimental group-2 (artificial saliva contamination, CHX rinsing, and subsequent 50 µm Al 2 O 3 sandblasting). FirstRTV was measured for each group, followed by different post-treatment procedures for the screws, and then Second-RTV was measured. During the procedure, the removal torque value and rotation angle vs. time were recorded at a 20 data/s.A standardized protocol was followed for all the tightening and loosening procedures: screw was tightened with 30 Ncm torque and maintained for 5 s, and then rotated in the reverse direction until the torque value reached 0 Ncm. After 10min of rest period, the screws were loosened to initial point. Results: . Statistical analysis of measured data revealed that the internal connection type showed significantly higher First-RTV compared to the external connection type, however, no significant differences in Second-RTV were found. Both experimental groups 1and 2 showed a decrease in RTVs for both implant types, while the control group showed a decrease in RTV only for the internal type. The internal connection type required a significantly larger rotation angle during the tightening and loosening process. Conclusion . Within the limitations of this study, both artificial saliva contamination and CHX cleansing, as well as sandblasting, decreased RTV in both internal and external connection types. Internal connections were more susceptible to the effects of contaminants.

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of midbrain dopaminergic neurons, leading to motor symptoms. While current treatments provide limited relief, they don’t alter disease progression. Stem cell technology, involving patient-specific stem cell-derived neurons, offers a promising avenue for research and personalized regenerative therapies. This article reviews the potential of stem cell-based research in PD, summarizing ongoing efforts, their limitations, and introducing innovative research models. The integration of stem cell technology and advanced models promises to enhance our understanding and treatment strategies for PD.

Purpose: . The purpose of this study is to analyze the biomechanical differences in rotation angle-torque according to the type of implant and to compare the effects of contamination and sandblasting on the removal torque value (RTV) of abutment screws. Materials and methods: . For this study, an automated device for tightening and loosening implant screws was developed, and each 15 implant-abutment complexes of external and internal connection type were prepared, divided into three groups according to the surface treatment of the screw:control group (no treatment), experimental group-1 (artificial saliva contamination and chlorhexidine (CHX) rinsing), and experimental group-2 (artificial saliva contamination, CHX rinsing, and subsequent 50 µm Al 2 O 3 sandblasting). FirstRTV was measured for each group, followed by different post-treatment procedures for the screws, and then Second-RTV was measured. During the procedure, the removal torque value and rotation angle vs. time were recorded at a 20 data/s.A standardized protocol was followed for all the tightening and loosening procedures: screw was tightened with 30 Ncm torque and maintained for 5 s, and then rotated in the reverse direction until the torque value reached 0 Ncm. After 10min of rest period, the screws were loosened to initial point. Results: . Statistical analysis of measured data revealed that the internal connection type showed significantly higher First-RTV compared to the external connection type, however, no significant differences in Second-RTV were found. Both experimental groups 1and 2 showed a decrease in RTVs for both implant types, while the control group showed a decrease in RTV only for the internal type. The internal connection type required a significantly larger rotation angle during the tightening and loosening process. Conclusion . Within the limitations of this study, both artificial saliva contamination and CHX cleansing, as well as sandblasting, decreased RTV in both internal and external connection types. Internal connections were more susceptible to the effects of contaminants.

Purpose: . The purpose of this study is to analyze the biomechanical differences in rotation angle-torque according to the type of implant and to compare the effects of contamination and sandblasting on the removal torque value (RTV) of abutment screws. Materials and methods: . For this study, an automated device for tightening and loosening implant screws was developed, and each 15 implant-abutment complexes of external and internal connection type were prepared, divided into three groups according to the surface treatment of the screw:control group (no treatment), experimental group-1 (artificial saliva contamination and chlorhexidine (CHX) rinsing), and experimental group-2 (artificial saliva contamination, CHX rinsing, and subsequent 50 µm Al 2 O 3 sandblasting). FirstRTV was measured for each group, followed by different post-treatment procedures for the screws, and then Second-RTV was measured. During the procedure, the removal torque value and rotation angle vs. time were recorded at a 20 data/s.A standardized protocol was followed for all the tightening and loosening procedures: screw was tightened with 30 Ncm torque and maintained for 5 s, and then rotated in the reverse direction until the torque value reached 0 Ncm. After 10min of rest period, the screws were loosened to initial point. Results: . Statistical analysis of measured data revealed that the internal connection type showed significantly higher First-RTV compared to the external connection type, however, no significant differences in Second-RTV were found. Both experimental groups 1and 2 showed a decrease in RTVs for both implant types, while the control group showed a decrease in RTV only for the internal type. The internal connection type required a significantly larger rotation angle during the tightening and loosening process. Conclusion . Within the limitations of this study, both artificial saliva contamination and CHX cleansing, as well as sandblasting, decreased RTV in both internal and external connection types. Internal connections were more susceptible to the effects of contaminants.

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of midbrain dopaminergic neurons, leading to motor symptoms. While current treatments provide limited relief, they don’t alter disease progression. Stem cell technology, involving patient-specific stem cell-derived neurons, offers a promising avenue for research and personalized regenerative therapies. This article reviews the potential of stem cell-based research in PD, summarizing ongoing efforts, their limitations, and introducing innovative research models. The integration of stem cell technology and advanced models promises to enhance our understanding and treatment strategies for PD.

Purpose: . The purpose of this study is to analyze the biomechanical differences in rotation angle-torque according to the type of implant and to compare the effects of contamination and sandblasting on the removal torque value (RTV) of abutment screws. Materials and methods: . For this study, an automated device for tightening and loosening implant screws was developed, and each 15 implant-abutment complexes of external and internal connection type were prepared, divided into three groups according to the surface treatment of the screw:control group (no treatment), experimental group-1 (artificial saliva contamination and chlorhexidine (CHX) rinsing), and experimental group-2 (artificial saliva contamination, CHX rinsing, and subsequent 50 µm Al 2 O 3 sandblasting). FirstRTV was measured for each group, followed by different post-treatment procedures for the screws, and then Second-RTV was measured. During the procedure, the removal torque value and rotation angle vs. time were recorded at a 20 data/s.A standardized protocol was followed for all the tightening and loosening procedures: screw was tightened with 30 Ncm torque and maintained for 5 s, and then rotated in the reverse direction until the torque value reached 0 Ncm. After 10min of rest period, the screws were loosened to initial point. Results: . Statistical analysis of measured data revealed that the internal connection type showed significantly higher First-RTV compared to the external connection type, however, no significant differences in Second-RTV were found. Both experimental groups 1and 2 showed a decrease in RTVs for both implant types, while the control group showed a decrease in RTV only for the internal type. The internal connection type required a significantly larger rotation angle during the tightening and loosening process. Conclusion . Within the limitations of this study, both artificial saliva contamination and CHX cleansing, as well as sandblasting, decreased RTV in both internal and external connection types. Internal connections were more susceptible to the effects of contaminants.

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of midbrain dopaminergic neurons, leading to motor symptoms. While current treatments provide limited relief, they don’t alter disease progression. Stem cell technology, involving patient-specific stem cell-derived neurons, offers a promising avenue for research and personalized regenerative therapies. This article reviews the potential of stem cell-based research in PD, summarizing ongoing efforts, their limitations, and introducing innovative research models. The integration of stem cell technology and advanced models promises to enhance our understanding and treatment strategies for PD.

Purpose: . The purpose of this study is to analyze the biomechanical differences in rotation angle-torque according to the type of implant and to compare the effects of contamination and sandblasting on the removal torque value (RTV) of abutment screws. Materials and methods: . For this study, an automated device for tightening and loosening implant screws was developed, and each 15 implant-abutment complexes of external and internal connection type were prepared, divided into three groups according to the surface treatment of the screw:control group (no treatment), experimental group-1 (artificial saliva contamination and chlorhexidine (CHX) rinsing), and experimental group-2 (artificial saliva contamination, CHX rinsing, and subsequent 50 µm Al 2 O 3 sandblasting). FirstRTV was measured for each group, followed by different post-treatment procedures for the screws, and then Second-RTV was measured. During the procedure, the removal torque value and rotation angle vs. time were recorded at a 20 data/s.A standardized protocol was followed for all the tightening and loosening procedures: screw was tightened with 30 Ncm torque and maintained for 5 s, and then rotated in the reverse direction until the torque value reached 0 Ncm. After 10min of rest period, the screws were loosened to initial point. Results: . Statistical analysis of measured data revealed that the internal connection type showed significantly higher First-RTV compared to the external connection type, however, no significant differences in Second-RTV were found. Both experimental groups 1and 2 showed a decrease in RTVs for both implant types, while the control group showed a decrease in RTV only for the internal type. The internal connection type required a significantly larger rotation angle during the tightening and loosening process. Conclusion . Within the limitations of this study, both artificial saliva contamination and CHX cleansing, as well as sandblasting, decreased RTV in both internal and external connection types. Internal connections were more susceptible to the effects of contaminants.

Primary cilia function as critical sensory organelles that mediate multiple signaling pathways, including the Hedgehog (Hh) pathway, which is essential for organ patterning and morphogenesis. Disruptions in Hh signaling have been implicated in supernumerary tooth formation and molar fusion in mutant mice. Cilk1, a highly conserved serine/threonine-protein kinase localized within primary cilia, plays a critical role in ciliary transport. Loss of Cilk1 results in severe ciliopathy phenotypes, including polydactyly, edema, and cleft palate. However, the role of Cilk1 in tooth development remains unexplored. In this study, we investigated the role of Cilk1 in tooth development. Cilk1 was found to be expressed in both the epithelial and mesenchymal compartments of developing molars. Cilk1 deficiency resulted in altered ciliary dynamics, characterized by reduced frequency and increased length, accompanied by downregulation of Hh target genes, such as Ptch1 and Sostdc1, leading to the formation of diastemal supernumerary teeth. Furthermore, in Cilk1^-/-;PCS1-MRCS1^△/△ mice, which exhibit a compounded suppression of Hh signaling, we uncovered a novel phenomenon: diastemal supernumerary teeth can be larger than first molars. Based on these findings, we propose a progressive model linking Hh signaling levels to sequential changes in tooth patterning: initially inducing diastemal supernumerary teeth, then enlarging them, and ultimately leading to molar fusion. This study reveals a previously unrecognized role of Cilk1 in controlling tooth morphology via Hh signaling and highlights how Hh signaling levels shape tooth patterning in a gradient-dependent manner.
Animals ; Hedgehog Proteins/physiology* ; Mice ; Signal Transduction/physiology* ; Tooth, Supernumerary ; Molar ; Cilia/physiology* ; Odontogenesis/physiology* ; Patched-1 Receptor ; Protein Serine-Threonine Kinases/physiology* ; Mice, Knockout ; Adaptor Proteins, Signal Transducing

Background: An international reference measurement laboratory network for creatinine (Cr) is lacking; therefore, Korea developed an independent evaluation and certification system. The in vitro diagnostics (IVD) certification program, launched in 2017, formed part of a broader Cr standardization initiative intended to enhance accuracy at the manufacturing stage. Methods: The program was designed to evaluate analytical systems, including all reagent lots, calibrators, and instrument models, twice annually. Bias, imprecision, total error (TE), and linearity were evaluated based on established acceptance criteria. A post-certification process allows submission for a second challenge and validation of corrective actions. Results: Between 2017 and 2023, 489 analytical systems were evaluated. Average acceptance rates for bias, imprecision, TE, and linearity were 70.8%, 95.9%, 87.7%, and 87.8%, respectively. The lowest acceptance rate for bias evaluation was 8.7% for the kinetic Jaffe method without compensation in 2018. Over the 7-year period, the mean absolute percentage bias (absBias%), coefficient of variation (CV), and TE were 4.62%, 1.37%,and 7.29%, respectively. The highest absBias% (7.94%) was observed in the 0.0 ≤ Cr < 1.0target value range. Since 2019, a consistent reduction in absBias% has been observed. Conclusions This program is a pioneering response to the absence of a global certification program for Cr assays. It offers significant advantages, including comprehensive evaluations, fee-free participation, and a robust post-certification process. Continuous participation and improvement efforts by manufacturers have contributed to enhanced accuracy in Cr assays.