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Journal of Pharmacy & Bioallied Sciences Feb 2024Surface roughness of the crowns is dependent on the pattern material used for the making as well as the procedure of investing. The study was aimed to examine the impact...
INTRODUCTION
Surface roughness of the crowns is dependent on the pattern material used for the making as well as the procedure of investing. The study was aimed to examine the impact of various pattern materials and investment procedures on the surface roughness of nickel-chromium alloy raw castings.
MATERIALS AND METHODS
An study was piloted at a tertiary care hospital. Eighty samples of inlay wax and pattern resin were divided equally. They were invested in phosphate-bonded investment material and kept under normal atmospheric pressure as well as invested under a pressure of 3 bars. The surface roughness was calculated with a Profilometer. The values obtained were compared using statistical tools keeping < 0.05 as significant.
RESULTS
Lowest surface roughness was seen for the wax pattern invested under positive pressure. While the highest was seen for the resin patterns invested at room pressure. A significant variance between the wax 1 and wax 2 ( < 0.01); as well as between the wax 2 vs. Resin 2 specimens ( < 0.01) was noted.
CONCLUSIONS
Wax patterns can be suggested as the material and method of choice because they showed the least amount of surface roughness when placed under pressure. Resin patterns when invested under pressure can also be suggested as an alternate as they also exhibited similar surface roughness as that of the wax.
PubMed: 38595557
DOI: 10.4103/jpbs.jpbs_445_23 -
Journal of Pharmacy & Bioallied Sciences Feb 2024The esthetic during the various orthodontic treatments has led to the invention of the brackets. When different ceramic brackets and archwires are used, the different...
INTRODUCTION
The esthetic during the various orthodontic treatments has led to the invention of the brackets. When different ceramic brackets and archwires are used, the different frictional forces may result in the different outputs. Hence, in the present study, we evaluated and compared the frictional resistance between eight standard monocrystalline ceramic bracket models and each of the archwires of four different alloys.
MATERIALS AND METHODS
Frictional force was tested using Instron testing machine, , for eight types of monocrystalline ceramic bracket, and four types of archwires beta-titanium, NiTi, copper-nickel-titanium, and stainless steel statistical analysis were done using various tools, and significance value of <0.05 was considered.
RESULTS
Ormco and AO (Radiance) monocrystalline ceramic brackets created lesser frictional resistance than other monocrystalline ceramic brackets. Stainless steel archwire generates lesser static friction. Beta-titanium archwire created higher static friction. A 0.017 × 0.025 inch stainless steel archwire generates lesser static friction to 0.019 × 0.025 inch TMA.
CONCLUSION
It can be concluded that Ormco and AO (Radiance) monocrystalline ceramic brackets, with stainless steel archwires and of size 0.017 × 0.025 inch, can generate better forces when used for the orthodontic tooth movements.
PubMed: 38595439
DOI: 10.4103/jpbs.jpbs_572_23 -
Cureus Mar 2024The transverse dimension, often overlooked in orthodontics, plays a crucial role in malocclusions, affecting not only occlusion in that dimension but also sagittal and...
The transverse dimension, often overlooked in orthodontics, plays a crucial role in malocclusions, affecting not only occlusion in that dimension but also sagittal and vertical dimensions. Posterior crossbites, indicative of transverse maxillary issues, are commonly addressed through palatal expansion. This case report explores the clinical insights into addressing a constricted maxillary arch in Angle's Class II malocclusion using a nickel-titanium (NiTi) expander. The NiTi expander provides constant and optimal expansion forces by incorporating a temperature-activated NiTi alloy. A 16-year-old male with irregularly placed teeth, high palatal vault, and posterior crossbite underwent treatment involving NiTi expander usage for maxillary expansion. The case presentation details the patient's journey, starting with upper arch bonding and expansion, then lower arch bonding, and concluding with complete leveling and alignment without extractions. The presented case demonstrates successful correction of a constricted maxillary arch, specifically in the canine and molar regions, utilizing the NiTi expander. The observed increase in intermolar width aligns with previous studies, showcasing the effectiveness of slow maxillary expansion. This article contributes valuable clinical insights into addressing transverse maxillary issues, emphasizing the importance of careful consideration in choosing the appropriate expansion method for optimal results.
PubMed: 38586693
DOI: 10.7759/cureus.55798 -
Dental Materials Journal Jun 2024The aim of this study was to evaluate how preset torque settings influence the torque, vertical force, and root canal-centering ability of ProGlider and ProTaper NEXT...
Effect of preset torque setting on torque/force generation, shaping ability and surface changes of nickel titanium rotary instrument in different root canal curvature locations: An ex vivo study.
The aim of this study was to evaluate how preset torque settings influence the torque, vertical force, and root canal-centering ability of ProGlider and ProTaper NEXT nickel-titanium rotary instruments in canals with different curvature locations. Based on micro-computed tomography, mesial roots of human mandibular molars (25°-40° curvature) were allocated to the apical curvature (apical 1-5 mm) or the middle curvature (apical 5-9 mm) groups, and mandibular incisors (curvature <5°) to the straight canal group. Each group was subjected to automated instrumentation and torque/force measurement with the preset torque of 1, 2.5, or 5 N•cm. Canal-centering ratios were determined with micro-computed tomography. Instrument fracture occurred only in the 2.5 and 5 N•cm groups in curved canals. The preset torque setting and curvature location did not influence canal shaping ability.
Topics: Torque; Humans; Titanium; Nickel; Root Canal Preparation; X-Ray Microtomography; Surface Properties; In Vitro Techniques; Dental Pulp Cavity; Molar; Dental Instruments; Materials Testing; Equipment Design; Dental Alloys; Dental Stress Analysis
PubMed: 38583993
DOI: 10.4012/dmj.2023-244 -
Journal of Dentistry May 2024To evaluate whether post-milling firing and material type affect the fabrication trueness and internal fit of lithium disilicate crowns.
OBJECTIVES
To evaluate whether post-milling firing and material type affect the fabrication trueness and internal fit of lithium disilicate crowns.
METHODS
A prefabricated cobalt chromium abutment was digitized to design a mandibular right first molar crown. This design file was used to fabricate crowns from different lithium disilicate ceramics (nano-lithium disilicate (AM), fully crystallized lithium disilicate (IN), advanced lithium disilicate (TS), and lithium disilicate (EX)) (n = 10). Crowns, the abutment, and the crowns when seated on the abutment were digitized by using an intraoral scanner. Fabrication trueness was assessed by using the root mean square method, while the internal fit was evaluated according to the triple scan method. These processes were repeated after the post-milling firing of AM, TS, and EX. Paired samples t-tests were used to analyze the effect of post-milling firing within AM, TS, and EX, while all materials were compared with 1-way analysis of variance and Tukey HSD tests (α = 0.05).
RESULTS
Post-milling firing reduced the surface deviations and internal gap of AM and EX (P ≤ 0.014). AM mostly had higher deviations and internal gaps than other materials (P ≤ 0.030).
CONCLUSIONS
Post-milling firing increased the trueness and internal fit of tested nano-lithium disilicate and lithium disilicate ceramics. Nano-lithium disilicate mostly had lower trueness and higher internal gap; however, the maximum meaningful differences among tested materials were small. Therefore, the adjustment duration and clinical fit of tested crowns may be similar.
CLINICAL SIGNIFICANCE
Tested lithium disilicate ceramics may be suitable alternatives to one another in terms of fabrication trueness and internal fit, considering the small differences in measured deviations and internal gaps.
Topics: Dental Porcelain; Crowns; Humans; Dental Prosthesis Design; Computer-Aided Design; Materials Testing; Dental Abutments; Ceramics; Surface Properties; Dental Materials; Dental Marginal Adaptation; Chromium Alloys
PubMed: 38580056
DOI: 10.1016/j.jdent.2024.104987 -
PloS One 2024The objective was to evaluate the effect of glide path and coronal flaring on the dentin volume removal and percentage of touched walls in curved canals using two...
The objective was to evaluate the effect of glide path and coronal flaring on the dentin volume removal and percentage of touched walls in curved canals using two heat-treated rotary files. The mesiobuccal canal of forty-eight, randomly selected, extracted mandibular molars was divided into two groups of 24 each, according to the type of instrument used (RACE EVO and EdgeSequel rotary files). Each group was further divided into three subgroups; Group (A): Control using one file shaped to 04/30, Group (B) with a glide path (EdgeGlidePath (EGP)), and Group (C): with a glide path and coronal flaring (EGP and EdgeTaper Platinum (ETP) SX file respectively). The root canals were then instrumented using the assigned instruments. The assessment was carried out using micro-CT. The comparison of the mean values of the tested groups about dentin volume removal and percentage of untouched walls did not reach statistical significance (p<0.05). Glide path and coronal flaring had an insignificant effect on the dentin volume removal and percentage of untouched walls in curved canals.
Topics: X-Ray Microtomography; Root Canal Preparation; Hot Temperature; Alloys; Titanium; Dental Pulp Cavity; Equipment Design; Nickel
PubMed: 38568900
DOI: 10.1371/journal.pone.0299896 -
Skin Research and Technology : Official... Apr 2024The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived...
BACKGROUND
The physical appearance of an individual plays a primary role as it influences the opinion of the viewer. For this reason, orthodontic therapy to improve perceived aesthetics is in high demand among patients. This factor, combined with the increase in the number of non-invasive facial aesthetic treatments, has led to the need to understand potential risk factors in the application of medical devices to the perioral skin in patients with fixed orthodontic appliances. The aim of this study was to evaluate in vitro heating of the orthodontic bracket following electromagnetic fields and negative pressure (V-EMF) used as an anti-aging treatment.
METHODS
Two different types of titanium alloy wires, one made of "beta-Titanium" alloy and the other "Ni-Ti" (DW Lingual Systems GmbH-Bad Essen-Germany) were used. The orthodontic wires and brackets mounted on a resin mouth were covered with porcine muscle tissue, then subjected to anti-aging therapy with a Bi-one LifeTouchTherapy medical device (Expo Italia Srl-Florence-Italy) which generates a combination of vacuum and electromagnetic fields (V-EMF) already adopted for antiaging therapy. During administration of the therapy, the orthodontic brackets and porcine tissue were thermally monitored using a Wavetek Materman TMD90 thermal probe (Willtek Communications GmbH-Germany). In total 20 orthodontic mouths were used, 10 with Beta Titanium wires and 10 with Nickel Titanium wires.
RESULTS
A temperature increase of about 1°C was recorded in each group. The outcome of the present research shows that the absolute temperatures measured on orthodontic appliances, which, despite having a slightly different curve, both show an increase in temperature of 1.1°C at the end of the session, thus falling well within the safety range of 2°C as specified by the standard CENELEC EN 45502-1. Therefore, V-EMF therapy can be considered safe for the entire dental system and for metal prostheses, which tend to heat up at most as much as biological tissue (+0.9°C/1.1°C vs. 1.1°C/1.1°C).
CONCLUSION
In conclusion, anti-aging therapy with V-EMF causes a thermal increase on orthodontic brackets that is not harmful to pulp health.
Topics: Humans; Animals; Swine; Titanium; Electromagnetic Fields; Vacuum; Heating; Orthodontic Wires; Alloys; Materials Testing; Nickel
PubMed: 38566505
DOI: 10.1111/srt.13687 -
Cureus Mar 2024This case report explores the innovative application of the endocrown technique for restoring a severely damaged mandibular molar (tooth #46) in a 28-year-old male...
This case report explores the innovative application of the endocrown technique for restoring a severely damaged mandibular molar (tooth #46) in a 28-year-old male patient. With a recent root canal treatment history, the patient presented with a dislodged prosthesis. Due to financial constraints, a base metal alloy was chosen for the endocrown restoration. The unique preparation process involved reducing the occlusal surface by 2 mm, creating a shoulder cervical margin, and preserving enamel walls. The endocrown, crafted from a base metal alloy, demonstrated a semi-conservative approach, providing cost-effectiveness and minimal tooth preparation. The case adheres to the 2013 CAse REport (CARE) guidelines. The discussion highlights the biomechanical benefits of the endocrown, emphasizing stress resistance, stability, and superior performance compared to traditional treatments. Materials like ceramic, resin nanoceramic, and polyetheretherketone are briefly discussed, focusing on the promising success rates of endocrowns, mainly through computer-aided designing/computer-aided manufacturing systems. The report provides valuable insights for clinicians considering this endocrown technique in reconstructing severely damaged molars and premolars.
PubMed: 38562352
DOI: 10.7759/cureus.55319 -
Journal of Clinical Medicine Mar 2024Scientific literature lacks strong support for using narrow diameter implants (NDI) in high masticatory force areas, especially in molars. Implant splinting in cases of...
Scientific literature lacks strong support for using narrow diameter implants (NDI) in high masticatory force areas, especially in molars. Implant splinting in cases of multiple missing teeth reduces lateral forces, improves force distribution, and minimizes stress on implants. However, no studies have evaluated the fatigue load resistance of unitary or splinted implants. This in vitro study compares five groups of new metal alloy implants, including unitary and splinted implants with varying diameters. Mechanical characterization was assessed using a BIONIX 370 testing machine (MTS, Minneapolis, MN, USA) according to ISO 14801. For each of the five study sample groups, (n = 5) specimens underwent monotonic uniaxial compression at break testing and (n = 15) cyclic loading to determine the maximum force (Fmax) and the fatigue life (LF) values. Scanning electron microscopy (SEM) was employed for the fractographic analysis of the fractured samples. The Fmax values for unitary samples ranged from 196 N to 246 N, whereas the two-splinted samples displayed significantly higher values, ranging from 2439 N to 3796 N. Similarly, the LF values for unitary samples ranged from 118 N to 230 N, while the two-splinted samples exhibited notably higher values, ranging from 488 N to 759 N. The observed resistance difference between sample groups in terms of Fmax and LF may be due to variations in effective cross-sectional area, determined by implant diameter and number. Additionally, this disparity may indicate a potential stiffening effect resulting from the splinting process. These findings have significant implications for dental clinical practice, suggesting the potential use of splinted sets of small-sized NDI as replacements for posterior dentition (premolars and molars) in cases of alveolar bone ridge deficiencies.
PubMed: 38541858
DOI: 10.3390/jcm13061632 -
Materials (Basel, Switzerland) Mar 2024Titanium is the most used material for implant production. To increase its biocompatibility, continuous research on new coatings has been performed by the scientific...
Titanium is the most used material for implant production. To increase its biocompatibility, continuous research on new coatings has been performed by the scientific community. The aim of the present paper is to prepare new coatings on the surfaces of the pure Ti Grade 2 and the Ti6Al4V alloy. Three types of coatings were achieved by applying anodization and chemical vapor deposition (CVD) methods: TiO nanotubes (TNTs) were formed by anodization, carbon nanotubes (CNTs) were obtained through a metal-catalyst-free CVD process, and a bilayer coating (TiO nanotubes/carbon nanostructures) was prepared via successive anodization and CVD processes. The morphology and structure of the newly developed coatings were characterized using SEM, EDX, AFM, XRD, and Raman spectroscopy. It was found that after anodization, the morphology of the TiO layer on pure Ti consisted of a "sponge-like" structure, nanotubes, and nano-rods, while the TNTs layer on the Ti alloy comprised mainly nanotubes. The bilayer coatings on both materials demonstrated different morphologies: the pure Ti metal was covered by a layer of nanotubular and nano-rod TiO structures, followed by a dense carbon layer decorated with carbon nanoflakes, and on the Ti alloy, first, a TNTs layer was formed, and then carbon nano-rods were deposited using the CVD method.
PubMed: 38541444
DOI: 10.3390/ma17061290