ABSTRACT
Objective: To study the long-term morphological stability of three-dimensional (3D) printed photosensitive resin dental models under natural light and dark conditions. Methods: Eighty sets of resin dental models were made by the desktop 3D printer from one digital standard model set, and randomly divided into two groups, namely natural light group (40 sets) and dark group (40 sets). All resin models were stored in sealed bags, with 4 model sets from each group randomly collected after 1, 3, 5, 7, 14, 21, 28, 40, 60, or 90 days of storage and 3D scanned using an optical model scanner. The root-mean-square error (RMSE) was calculated to represent the mean deviation of the difference between the digital standard model and the scanned resin model. Meanwhile, three linear indexes (the width between the canines, the width between the first molars, and the arch length) of the resin dental model were measured and compared with the corresponding values of the standard model. RMSE and the linear measurements between the digital standard model and the scanned resin models were compared between the natural light group and the dark group and among models from different time points. Results: Compared with the digital standard model, the RMSE values of 96.9% (155/160) resin dental models were less than 0.1 mm within 90-day storage. Also, at the same time point, there was no significant difference in the RMSE between the natural light group and the dark group (P>0.05). 75.0% (360/480) of the absolute values of the linear differences (differences in inter-canine width, intra-molar width, and arch length between the digital standard model and the scanned resin model) were within 0.2 mm, and about 0.1% (3/480) of the linear differences were greater than 0.5 mm, and all of the linear differences were within 0.6 mm. Conclusions: 3D-printed resin dental models can be stored stably under natural light and dark conditions for a long time.
ABSTRACT
West Nile virus (WNV) causes West Nile fever and West Nile encephalitis. Because infection by WNV creates serious public health problems, its simple, rapid, and visual detection is very important in clinical practice, especially in resource-limited laboratories. We have developed a rapid, specific, and highly sensitive internally controlled reverse transcription recombinase-aided amplification (RTRAA) assay to detect WNV, using both real-time fluorescence and the lateral flow dipstick (LFD) at 39.0 °C for 30 min. The analytical sensitivity of the RT-RAA assay was 10 plasmid copies and 1.6 pfu per reaction with real-time fluorescence, and 1,000 plasmid copies per reaction with the LFD. No crossreaction with other control viruses was observed. Compared with the RT-qPCR assay, the RT-RAA assay demonstrated 100% sensitivity and 100% specificity for WNV.
ABSTRACT
Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
ABSTRACT
Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
ABSTRACT
Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets. Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed, including three kinds of materials (stainless steel, beta-titanium, nickel-titanium) and two sizes of arch wires (0.43 mm×0.56 mm, 0.41 mm×0.56 mm), so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°. Results With the increase in elastic modulus of the arch wire, torque moments of lingual brackets with horizontal and vertical slot both increased gradually. Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots. The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle. The effect of arch wire sizes was smaller than that of arch wire materials, while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets. Conclusion The lingual brackets with different slot directions, sizes and materials of arch wires will influence the torque performance of lingual brackets. In clinical application, slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
ABSTRACT
Objective Objective To analyze the torque performance of lingual brackets with slots in different directions and the influence pattern of arch wires with different sizes and materials on torque of these lingual brackets.Methods The finite element models of the anterior maxilla lingual brackets with vertical and horizontal slot were constructed,using 3 kinds of materials (stainless steel,beta-titanium,nickel-titanium) and two sizes of arch wires (0.43 mm x 0.56 mm,0.41 mm x 0.56 mm),so as to compare and analyze their mechanical properties after the application of torque load on the left upper central incisors with a rotation angle of ±20°.Results With the increase in elastic modulus of the arch wire,torque moments of lingual brackets with horizontal and vertical slot both increased gradually.Torque performance of lingual brackets was affected more by the sizes and materials of arch wires than the directions of slots.The lingual bracket with vertical slot produced 1-2 times of torque force than that with horizontal slot under the same degree of torque angle.The effect of arch wire sizes was smaller than that of arch wire materials,while the synergistic change in sizes and materials of arch wires had the largest influence on torque performance of lingual brackets.Conclusions The torque performance of lingual bracket will be influenced with its different slot directions,the sizes and materials of arch wires.In clinical application,slot directions of lingual brackets as well as sizes and materials of arch wires should be adjusted properly according to the required torque force.
ABSTRACT
<p><b>Objective</b>To compare and analyze the effects of transurethral resection of the prostate (TURP) and transurethral holmium laser enucleation of the prostate (HoLEP) in the treatment of benign prostatic hyperplasia (BPH) with bladder detrusor overactivity.</p><p><b>METHODS</b>his study included 51 cases of BPH with bladder detrusor overactivity treated by TURP and another 58 treated by HoLEP. We evaluated the urination of the two groups of patients during the recovery period and at 3 and 6 months postoperatively.</p><p><b>RESULTS</b>There were no statistically significant differences in such baseline data as the blood PSA level, prostate volume, International Prostate Symptom Score (IPSS), and quality of life (QOL) between the two groups of patients, except in effective bladder capacity, which was higher in the TURP than in the HoLEP group (［315±59］ vs ［287±76］ ml, P<0.05). Urine storage symptoms were obviously improved in both of the groups postoperatively, with the storage symptoms score significantly decreased from 12.6±4.9 preoperatively to 7.5±3.9 at 3 months and 6.1±4.2 at 6 months after surgery in the TURP group (P<0.01) and from 13.7±5.7 to 7.9±4.2 and 7.0±5.1 in the HoLEP group (P<0.01). HoLEP manifested significant advantages over TURP in the postoperative urethral catheterization time (［2.7±0.8］ vs ［5.1±1.2］ d, P<0.05), postoperative bladder contracture time (［4.1±1.9］ vs ［5.8±2.4］ d, P<0.05), postoperative hospital stay (［4.4±1.8］ vs ［5.9±2.5］ d, P<0.05), and improvement of the maximum urinary flow rate, which was increased from (7.9±3.7) ml/s preoperatively to (16.8±4.3) ml/s at 3 months after surgery in the HoLEP group and from (8.6±3.2) ml/s to (14.6±4.3) ml/s in the TURP group (P<0.05).</p><p><b>CONCLUSIONS</b>Both TURP and HoLEP can improve bladder function and detrusor overactivity in BPH patients, with similar effects in improving urination at 3 to 6 months after surgery. However, HoLEP has more advantages over TURP during the period of postoperative recovery.</p>
Subject(s)
Humans , Male , Lasers, Solid-State , Therapeutic Uses , Length of Stay , Prostate , General Surgery , Prostatic Hyperplasia , General Surgery , Quality of Life , Transurethral Resection of Prostate , Methods , Treatment Outcome , Urinary Bladder Neck Obstruction , General Surgery , Urinary Bladder, Overactive , General Surgery , Urinary Catheterization , Urination , PhysiologyABSTRACT
α-smooth muscle actin (α-SMA) and tenascin-C are stress-induced phenotypic features of myofibroblasts. The expression levels of these two proteins closely correlate with the extracellular mechanical microenvironment. We investigated how the expression of α-SMA and tenascin-C was altered in the periodontal ligament (PDL) under orthodontic loading to indirectly reveal the intrinsic mechanical microenvironment in the PDL. In this study, we demonstrated the synergistic effects of transforming growth factor-β1 (TGF-β1) and mechanical tensile or compressive stress on myofibroblast differentiation from human periodontal ligament cells (hPDLCs). The hPDLCs under higher tensile or compressive stress significantly increased their levels of α-SMA and tenascin-C compared with those under lower tensile or compressive stress. A similar trend was observed in the tension and compression areas of the PDL under continuous light or heavy orthodontic load in rats. During the time-course analysis of expression, we observed that an increase in α-SMA levels was matched by an increase in tenascin-C levels in the PDL under orthodontic load in vivo. The time-dependent variation of α-SMA and tenascin-C expression in the PDL may indicate the time-dependent variation of intrinsic stress under constant extrinsic loading.
Subject(s)
Adult , Animals , Humans , Male , Rats , Actins , Biomechanical Phenomena , Cell Culture Techniques , Cell Differentiation , Physiology , Cells, Cultured , Cellular Microenvironment , Physiology , Myofibroblasts , Physiology , Orthodontic Wires , Periodontal Ligament , Chemistry , Cell Biology , Pressure , Rats, Sprague-Dawley , Stress, Mechanical , Tenascin , Time Factors , Tooth Movement Techniques , Transforming Growth Factor beta1 , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To investigate the functions of human periodontal myofibroblast (MFB) in vitro.</p><p><b>METHODS</b>Human periodontal fibroblast (hPDLFs) was cultured and induced to MFB by transforming growth factor-β1 (TGF-β1). MFB was denoted as the experimental group, whereas the hPDLFs was the control group. The groups were continuously cultured and harvested at 0, 12, 24, 48, and 72 h. The MFB marker α-smooth muscle actin (α-SMA) was examined by immunocytochemistry. The expression of fibronectin (FN) between MFB was examined by immunocytochemistry to detect the MFB contact relationship. The mRNA expression levels of α-SMA, collagen (Col) I, and Col III were measured by reverse transcription-polymerase chain reaction (RT-PCT) to analyze extracellular matrix secretion. The protein expression levels of α-SMA and Col I were also assessed by Western blot.</p><p><b>RESULTS</b>The experimental group had significantly higher α-SMA expression than the control group at 0 h (P < 0.001). A positive expression of FN was found between MFB. The experimental group had significantly higher expression levels of Col I and Col III than the control group at 24 h (P < 0.001).</p><p><b>CONCLUSION</b>Human periodontal MFB presents a continuous, high expression of α-SMA. MFB could interact through FN. MFB is significantly capable of extracellular matrix secretion.</p>
Subject(s)
Humans , Actins , Epithelial Cells , Extracellular Matrix , Fibroblasts , Fibronectins , Jaw , Metabolism , Myofibroblasts , Transforming Growth Factor beta1ABSTRACT
Contemporary orthodontic care should be a team approach to achieve health and esthetics of soft and hard tissue. It should be given enough attention that periodontal health provides the foundation for tooth movement, and that distinct esthetic results can be achieved by subtle changes in tooth alignment and gingival contours. Orthodontic treatment planning should include evaluation of gingival health and esthetics to anticipate the need for interdisciplinary approaches. Studies on the effect of orthodontic treatment on gingiva can provides basis for maintaining gingival health and esthetic. This article will focus primarily on the gingival health and esthetic care in orthodontic treatment.
Subject(s)
Humans , Esthetics , Esthetics, Dental , Gingiva , Tooth Movement TechniquesABSTRACT
Articulators have been widely used by clinicians of dentistry. But routine articulator mounting is still controversial in orthodontics. Orthodontists oriented by gnathology approve routine articulator mounting while nongnathologic orthodontists disapprove it. This article reviews the thoughts of orthodontist that they agree or disagree with routine articulator mounting based on the considerations of biting, temporomandibular disorder (TMD), periodontitis, and so on.
Subject(s)
Humans , Dental Articulators , OrthodonticsABSTRACT
One of the ultimate goals for orthodontic treatment is to establish an esthetic, healthy, stable and efficient occlusion. Currently, however, most of the criteria are limited to static occlusion, with little attention to dynamic occlusion. During the therapy, the orthodontists may sometimes find the maximum intercuspation (MI) is remarkably inconsistent with the centric relation (CR), or the mandibular positions are different before and after the therapy. These definitely will influence the stability of the treatment, or even the health of temporomandibular joint (TMJ) and stomatognathic system. The functional occlusion theory emphasizes that the displacement of TMJ in the glenoid fossa is the reason for the inharmony between MI and CR, and the relapse. What is more, this theory also gives the orthodontists the ways to evaluate the relationships among the MI, CR and TMJ. In this paper, we will introduce the contents and methods of the functional occlusion theory.
Subject(s)
Humans , Dental Occlusion , Dental Occlusion, Centric , Mandible , Temporomandibular JointABSTRACT
To determine the effect of compression-force on the expression of alkaline phosphatase [ALP], and ALP activity in cementoblasts. We performed this study in the State Key Laboratory of Oral Diseases, West China Stomatology Hospital, Sichuan University, Chengdu, Sichuan, China from October to December 2010. We exposed murine immortalized cementoblasts [OCCM-30] to 2000-microstrain compression-force at a frequency of 0.5 Hz for 1, 3, 6, 12, and 24 hours. We assayed the cellular ALP activity after the treatments. We used real-time polymerase chain reaction [RT-PCR] and western blot to examine the gene and protein expression of ALP in the OCCM-30 cells at each time point. Two-thousand micro strain compressive force significantly up-regulated the mRNA expression of ALP in OCCM-30 cells, which reached a peak at 12 hours loading, and the protein expression change of ALP in response to compression-force was consistent with the variation of gene level. We also noted marked enhancement of ALP activity in OCCM-30 cells during the application of mechanical stress. The compression-force increased the expression of ALP in OCCM-30 cells, suggesting that mechanical stimulation may affect the cellular function of cementoblasts by regulating ALP expression, which may participate in cementum metabolism during orthodontic tooth movement
Subject(s)
Animals, Laboratory , Alkaline Phosphatase , Real-Time Polymerase Chain ReactionABSTRACT
HX straight-wire appliance (HX-SWA) is designed and adjusted by doctors of Orthodontic Department, West China College of Stomatology, Sichuan University. It is a set of appliance that is constructed according to normal occlusion features of the Chinese people, including the prescription of tip, torque, in/out, counter-tip, counter-rotation and overcorrection in brackets and buccal tubes. Some ingredients of the appliance are different from that of the most popular Roth straight-wire appliance in the world wide. Over a period of the last 10 years, doctors in our hospital kept on summarizing treatment experience with HX-SWA, which will help more doctors promote practice and results in orthodontic clinic.
Subject(s)
Humans , Dental Occlusion , Orthodontic Wires , RotationABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of loop configuration on appliance stiffness of stainless steel round wire.</p><p><b>METHODS</b>Some stainless steel round wires with various cross-sectional dimension (0.36, 0.41, 0.46 mm) were selected. Box loops, double horizontal loops, and double vertical loops were manufactured according to established parameters, and loading experiments were carried out with a micro-orthodontic archwire testing apparatus.</p><p><b>RESULTS</b>When the cross-sectional dimension and the span were identical, the appliance stiffness of the box loops, double horizontal loops, and double vertical loops increased successively.</p><p><b>CONCLUSION</b>Configuration of loops exert a great influence on appliance stiffness, and the mechanical properties of box loop are optimal. The force generated by box loop was lighter, slowly decreasing, and easier to be controlled. The activation range of box loop (0.41 mm) was appropriate when the produced optimal moment was between 0.01-0.02 N.m. Box loop (0.41 mm) is preferred to rectify the individual tooth with mild or moderate mesiodistal displacement.</p>
Subject(s)
Cross-Sectional Studies , Orthodontic Appliance Design , Orthodontic Wires , Stainless SteelABSTRACT
<p><b>OBJECTIVE</b>To study the properties of orthodontic rectangular arch wires in torsion.</p><p><b>METHODS</b>By using the torsion measurement apparatus, torsion moments and angles of four kinds of orthodontic wires (0.46 mm x 0.63 mm and 0.48 mm x 0.63 mm stainless steel wires, and the same size nickel-titanium wires) were tested respectively in a 0.56 mm-slot first maxillary incisor bracket. According to the torsion moments and angles, scatter graphs were drawn to fit the load-deflection curves of four kinds of wires and their linear equations were calculated. According to the equations, the torsion stiffness and the play angles of the wires at 20 N mm correspondingly were calculated.</p><p><b>RESULTS</b>The torsion stiffness of four kinds of wires were 4.909, 6.417, 1.325 and 1.363 N mn/degrees, the torsion angles of different wires were 19.14 degrees, 15.33 degrees, 36.83 degrees and 35.07 degrees at 20 N mm respectively.</p><p><b>CONCLUSION</b>The torsion stiffness of stainless steel wires was bigger than that of the same cross-section dimensional nickel-titanium wires. The difference of torsion stiffness between two dimensional nickel-titanium wires is smaller, while the difference of torsion stiffness between two stainless steel wires is larger.</p>
Subject(s)
Incisor , Nickel , Orthodontic Wires , Stainless Steel , TitaniumABSTRACT
<p><b>OBJECTIVE</b>To explore certain principle of how osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) take part in the periodontal tissues remodeling under the combined influence of inflammation and orthodontic force.</p><p><b>METHODS</b>The positive signals of OPG and OPGL mRNA were measured with in situ hybridzation after orthodontic tooth movement in the experimental periodontitis groups and control ones.</p><p><b>RESULTS</b>The OPG and OPGL mRNA expression intensity in the experimental group showed difference from control. All their optical density index reached a peak in day 2, respectively.</p><p><b>CONCLUSION</b>OPG and OPGL play important roles in the periodontal reconstruction induced by inflammation irritation and orthodontic force, and complex interaction could exist between the two factors.</p>
Subject(s)
Humans , Osteoprotegerin , Periodontitis , RANK Ligand , RNA, Messenger , Tooth Movement TechniquesABSTRACT
<p><b>OBJECTIVE</b>To investigate the bending mechanical properties and provide reference for orthodontists to select the proper wires during alignment stage.</p><p><b>METHODS</b>In order to analyze the load deflection rate of NiTi round wire quantitatively, some NiTi round wires of different cross-sectional dimension (0.36, 0.41, 0.46 mm) were selected. Then loading-unloading experiments were carried out with the micro-orthodontic archwire testing apparatus and double end bending test could be accomplished with the wire in a 0.56 mm x 0.71 mm standard incisor edgewise bracket slot.</p><p><b>RESULTS</b>Under the load of 0.03 N.m, 0.36 and 0.41 mm NiTi round wire showed excellent super-elasticity, while 0.46 mm NiTi round wire didn't. When the optimal moment produced by the archwire was between 0.01 N.m and 0.02 N.m, the bending range of 0.36, 0.41 and 0.46 mm NiTi round wires was from 21.0 degrees to 49.5 degrees , 7.2 degrees to 23.7 degrees , and 6.5 degrees to 9.5 degrees , respectively after deducting the contact angle.</p><p><b>CONCLUSIONS</b>On the premises of yielding effective orthodontic force, the preferable NiTi round wire for alignment was the one which could produce continuous and slowly declining force.</p>
Subject(s)
Dental Alloys , Materials Testing , Mechanics , Nickel , Orthodontic Wires , TitaniumABSTRACT
<p><b>OBJECTIVE</b>To explore the combined effects of orthodontic force and inflammation on the remodelling of periodontal tissues.</p><p><b>METHODS</b>The upper first molars underwent mesial orthodontic force on 48 rats suffering experimental periodontitis and 48 rats injected lipopolysaccharide, respectively.</p><p><b>RESULTS</b>The TNF-alpha protein expression in the compressed periodontal tissues fluctuated during 0, 2, 12 hours and 2, 7, 14 days stages, the OD value got to the peak in the compressed periodontal tissues in 2 days.</p><p><b>CONCLUSION</b>The mechanical remodelling effects were hindered due to the circumstance of acute or chronic inflammation. The research suggests that the orthodontic treatment to adult patients with periodontal inflammation should be taken carefully.</p>
Subject(s)
Adult , Animals , Humans , Rats , Molar , Periodontitis , Stress, Mechanical , Tumor Necrosis Factor-alphaABSTRACT
<p><b>OBJECTIVE</b>To study the incisal jaw morphology of subjects with normal occlusion and to discuss the relationship between different vertical facial skeletal types and different incisal jaw cluster types.</p><p><b>METHODS</b>After studied by radiographic cephalometry, the incisal jaw morphology of 169 subjects with normal occlusion in early permanent dentition were analyzed by K-mean cluster analysis.</p><p><b>RESULTS</b>Morphology of maxillary or mandibular incisal jaws could be divided into four types separately, including division I, division II, division III and division N. In maxilla or in mandible, the incisal jaw morphology of division I was characterized by wideness and shortness. In contrast, division II was characterized by thinness and length. As for division III and division IV, both of two were intermediate types between division I and division II . In maxilla, it was found that division II was the majority (86.49%) in the high-angle subjects, division III was the majority (47.67%) in the average-angle subjects, and division I and III were the majority (82.61%) in the low-angle subjects. In mandible, it was found that division II was the majority (51.35%) in the high-angle subjects, division IV was the majority (48.84%) in the average-angle subjects, and division III and IV were the majority (69.57%) in the low-angle subjects.</p><p><b>CONCLUSION</b>Owing to the obvious characteristics of morphology in each cluster types and in each vertical facial skeletal types, different clinic considerations must be put forward when we want to move the incisor.</p>