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Journal of Clinical Orthodontics : JCO May 2024
Topics: Humans; Orthodontic Wires; Orthodontic Appliance Design; Female; Tooth Movement Techniques; Dental Alloys; Malocclusion; Male; Adolescent
PubMed: 38917040
DOI: No ID Found -
Cureus May 2024To compare the bond strength of two types of resin cement to that of additive manufacturing (AM) or cast cobalt-chromium (Co-Cr) alloys.
OBJECTIVE
To compare the bond strength of two types of resin cement to that of additive manufacturing (AM) or cast cobalt-chromium (Co-Cr) alloys.
MATERIALS AND METHODS
Two types of resin luting cement, composite resin and methyl methacrylate (MMA), were bonded to AM or cast Co-Cr alloys, and shear bond tests were performed after seven days of storage in distilled water at 37°C. Co-Cr alloy adhesive elements AM to the enamel surface of the labial aspect of a bovine mandibular central incisor crown were bonded with two types of resin luting cement and subjected to 1,000 cycles of storage in water for one day and 28 days or thermal cycling, followed by shear bonding tests. Residual cement on the metal and enamel surfaces after the bonding tests was evaluated using an optical microscope. The normality of the results was evaluated using statistical software Statcel4, analysis of variance, or Kruskal-Wallis test, depending on normality, and multiple comparison tests were performed using the Tukey-Kramer or Steel-Dwass tests.
RESULTS
After one day, the shear bond strength (SBS) was 25.9 MPa for Panavia V5 (PV; Kuraray Noritake Dental Corporation, Niigata, Japan) and 23.5 MPa for Super-Bond (SB; Sun Medical Corporation, Shiga, Japan), with no significant difference between the two cement types (P > 0.05). After 28 days, the SBS decreased to 4.1 MPa for PV and 6.7 MPa for SB, showing a significant difference between the two cements (P < 0.05). Following 1,000 thermal cycles, the SBS was 2.0 MPa for PV and 5.6 MPa for SB, with SB exhibiting a significantly higher value (P < 0.05). The adhesive strength was significantly lower after 28 days of storage and thermal cycling compared to after one day of storage (P < 0.05). The Co-Cr alloy exhibited more residual cement on the enamel surface due to interfacial fracture with the resin cement. The Co-Cr alloy showed more residual cement on the enamel surface due to interfacial fracture with the resin cement.
CONCLUSION
MMA-based resin cement showed optimal bond strength and may be suitable for clinical use in computer-aided design (CAD)/computer-aided manufacturing (CAM) orthodontic appliances.
PubMed: 38916016
DOI: 10.7759/cureus.61041 -
Journal of Maxillofacial and Oral... Jun 2024Titanium and its alloys are the most popular choice of materials for the reconstruction of craniofacial defects. They have lighter weight and are nonferromagnetic, which...
Estimation of Titanium Levels in Blood Following Reconstruction of Post-Craniotomy Defect by Titanium Mesh Using Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES).
INTRODUCTION
Titanium and its alloys are the most popular choice of materials for the reconstruction of craniofacial defects. They have lighter weight and are nonferromagnetic, which makes them an advantage in cranial defect reconstruction. Although the formed oxide layer makes them corrosion-resistant, levels of titanium in blood have been seen in trace amounts. This is the first study as per authors' knowledge that a study of such kind has been conducted.
MATERIALS AND METHODS
A pilot study was carried out at a tertiary level hospital, considering the inclusion and exclusion criteria in patients who were planned for the reconstruction of the residual defect using titanium mesh. Preoperative and 03- and 06-months postoperative blood samples were collected and analyzed for estimating the levels of titanium ions in blood by inductively coupled plasma-optical emission spectroscopy (ICP-OES).
RESULTS
Friedman's two-way analysis of variance by ranks was considered for testing of hypothesis summary, owing to the smaller sample size. The analysis suggested an increase in levels was minimal. Considering the asymptotic significances (two-tailed significance), a significance level was 0.050, which directed us to reject the null hypothesis. Pairwise comparison suggested the presence of negative values indicating steady increase in levels. Cluster analysis indicated that although minimal there is a cluster of difference in the values at all three stages. Continuous field information was used to determine the level with regard to the level of titanium at the three stages of study.
CONCLUSION
The study revealed that the levels of titanium ions increase on prolonged contact with living tissues. The trace elements have to be analyzed at regular intervals. This first-of-the-time study if extended to larger sample size would reveal interesting facts.
PubMed: 38911419
DOI: 10.1007/s12663-023-02006-2 -
General Dentistry 2024The purpose of this study was to determine the most effective method for bonding composite resin to artificially aged amalgam. A spherical amalgam alloy was triturated...
The purpose of this study was to determine the most effective method for bonding composite resin to artificially aged amalgam. A spherical amalgam alloy was triturated and condensed by hand into cylindrical plastic molds (6 mm in diameter and 4 mm in height) to create 90 specimens, which were then aged for 2 weeks in closed plastic containers at 23°C. The amalgam surfaces underwent 1 of 3 surface treatments (n = 30 per treatment): (1) air particle abrasion (APA) with 50-μm aluminum oxide particles applied with a force of 45 psi from a 10-mm distance, followed by rinsing with deionized water for 60 seconds; (2) APA following the same protocol with subsequent application of a metal primer (Alloy Primer); or (3) coating with 30-μm silica (CoJet) at a force of 45 psi from a 10-mm distance until the surface turned black. Specimens were then treated with 1 of 3 adhesives (n = 10 per adhesive per surface treatment): (1) 2-step total-etch adhesive (OptiBond Solo Plus), (2) 1-step self-etching adhesive (Scotchbond Universal), or (3) dual-cured resin cement (Panavia F 2.0). Each adhesive was applied to the treated amalgam surfaces following its manufacturer's instructions. The specimens were placed in a bonding clamp, and nanocomposite resin columns, 2.38 mm in diameter and 2.00 mm in height, were photocured (40 seconds, 500 mW/cm) against the treated amalgam surfaces. The specimens were stored for 24 hours in 37°C deionized water and underwent shear bond strength testing at a crosshead speed of 0.5 mm/min. Data were analyzed using 2-way analysis of variance and post hoc analysis with the Tukey test at 95% confidence. The mean (SD) shear bond strength values ranged from 12.3 (1.2) MPa for aluminum oxide-treated surfaces bonded with OptiBond Solo Plus to 25.9 (4.6) MPa for silicoated surfaces bonded with Panavia F 2.0. All bonding agents produced the highest shear bond strength when the amalgam surface was silicoated. These results indicate that composite can be effectively bonded to amalgam via silicoating.
Topics: Dental Amalgam; Composite Resins; Dental Bonding; Surface Properties; Dental Restoration Repair; Humans; Resin Cements; Materials Testing; Shear Strength; Methacrylates; Thiones
PubMed: 38905606
DOI: No ID Found -
General Dentistry 2024The aim of this study was to identify and quantify artifacts produced by commonly used dental restorative materials in both standard and high-resolution cone beam...
The aim of this study was to identify and quantify artifacts produced by commonly used dental restorative materials in both standard and high-resolution cone beam computed tomographic imaging. In this in vitro study, 25 different dental materials were placed in holes (3 mm in diameter × 2 mm thick) prepared in the center of 10 × 10-mm polymethyl methacrylate plates. The specimens, along with a control plate prepared with an unfilled hole, were scanned at standard and high resolutions. The gray values (GVs) of the specimens were measured at 1-, 2-, 4-, and 8-mm distances from the material surfaces, and in 8 different directions, resulting in 32 measurements per specimen. The absolute value of the difference (ΔGV) between the GV of each measurement point on the specimen disc and the GV of the corresponding point on the control disc was considered to be the number of artifacts at that point. The median ΔGV of each material was calculated, and the materials were then ranked in terms of artifact formation using the Kruskal-Wallis test. At standard resolution, the greatest numbers of artifacts were caused by AH 26 root canal sealer and Heraenium S nickel-chromium alloy, and the fewest were caused by Whitepost DC #3 glass fiber post and ChemFil Superior glass ionomer cement. At high resolution, the greatest numbers of artifacts were found in amalgam (admix; SDI) and Heraenium S, and the fewest in Whitepost DC and GC Initial enamel porcelain. The median ΔGV values at standard and high resolutions were 46.0 and 57.0, respectively. High and standard resolutions were significantly different in terms of artifact formation (P = 0.001; Wilcoxon test). AH 26 sealer was the only material that demonstrated a statistically significant reduction in artifact formation at high resolution compared with standard resolution (P = 0.05; Wilcoxon test). The number of artifacts produced by dental materials at both resolutions decreased with an increasing distance from the surface of the material.
Topics: Artifacts; Cone-Beam Computed Tomography; Dental Materials; Humans; In Vitro Techniques; Materials Testing
PubMed: 38905603
DOI: No ID Found -
BMC Oral Health Jun 2024Failure of orthodontic bracket bonds is a common occurrence during orthodontic treatment. This study investigated the impact of Er: YAG laser-based removal of adhesive... (Comparative Study)
Comparative Study
BACKGROUND
Failure of orthodontic bracket bonds is a common occurrence during orthodontic treatment. This study investigated the impact of Er: YAG laser-based removal of adhesive from the bases of metal and ceramic brackets for re-bonding.
METHODS
A total of 168 extracted premolars were collected from patients. 84 metal brackets were used to be bonded on the buccal surface of the premolars in Groups 1, 2, 3 and 4, while 84 ceramic brackets were applied in Groups I, II, III and IV. Group 1/I represented the initial bonding group, with Group 2/II being the re-bonding group with new brackets, while Groups 3/III and 4/ IV received recycled brackets treated by Er: YAG laser or flaming respectively. Both the first and second de-bonding were performed in all samples using a universal testing machine to determine the shear bond strength (SBS). The adhesive remnant index (ARI) was evaluated using a stereo-microscope. The new and the treated bracket bases were evaluated using scanning electron microscopy (SEM). Differences in initial bonding and re-bonding ability were analyzed through one-way ANOVAs, and differences in ARI were assessed with the Kruskal-Wallis test.
RESULTS
Greater amounts of adhesive residue were observed on ceramic brackets treated by laser. The SBS values for recycled metal brackets in Group 3 (26.13 MPa) were comparable to Group 1 (23.62 MPa) whereas they differed significantly from Group 4 (12.54 MPa). No significant differences in these values were observed when comparing the 4 groups with ceramic brackets. ARI score in Group 4 (2-3 points) differed significantly from the three other groups (P < 0.05). For Group I, II, III and IV, similar ARI scores were observed (P > 0.05). SEM analysis didn't show apparent damage of bracket bases consisting of either metal or ceramic material treated by Er: YAG laser.
CONCLUSIONS
Er: YAG laser treatment was superior to flame treatment as a means of removing adhesive without damaging the brackets. SBS values and ARI scores following Er: YAG laser treatment were similar to those for new brackets, offering further support for Er: YAG laser treatment as a viable means of recycling debonded brackets.
Topics: Orthodontic Brackets; Lasers, Solid-State; Humans; Dental Bonding; Ceramics; Dental Debonding; Shear Strength; Dental Stress Analysis; Microscopy, Electron, Scanning; Materials Testing; Surface Properties; Bicuspid; Dental Alloys; Resin Cements
PubMed: 38902669
DOI: 10.1186/s12903-024-04504-2 -
American Journal of Dentistry Jun 2024To investigate the effect of different chemical compositions of primers on the bond strength between nano-ceramic, polymer-infiltrated ceramic, and zirconia ceramic...
PURPOSE
To investigate the effect of different chemical compositions of primers on the bond strength between nano-ceramic, polymer-infiltrated ceramic, and zirconia ceramic materials and dual-cure cement.
METHODS
Fifty 2 mm-thick specimens were prepared from Vita Enamic, Cerasmart, and Katana Zirconia UTML. The specimens were embedded in acrylic blocks. To standardize the surfaces, 600 grit silicon carbide abrasives were applied underwater for 60 seconds. Then, each section underwent grit-blasting using Al₂O₃ with a particle size of 50 µm at 10 mm and a pressure of 2 bar for 10 seconds. Each prepared sample from the experimental groups received the appropriate primer (Z-PRIME Plus, G-Multi Primer, Alloy Primer, Clearfil Primer Plus) according to the manufacturers' instructions. Subsequently, the prepared CAD-CAM specimens underwent cementation using Duo-Link Universal Adhesive Resin Cement with a cylinder mold of 2.6 mm diameter and 3 mm height. The cement was light-cured for 20 seconds from both sides. The specimens obtained were stored in distilled water at 37°C for 24 hours. The shear bond strength test of the specimens was performed using a Bisco Shear Bond Tester device. The data were statistically analyzed using ANOVA and the Kruskal-Wallis test (P< 0.05).
RESULTS
The highest bond strength was observed in Z-Prime Plus applied specimens, regardless of material differences (Cerasmart 11.60±4.61; Vita Enamic 12.93±3.86; Katana Zirconia 13.85±4.00). The lowest bond strength, showing differences according to materials (P< 0.05), was found for Clearfil Ceramic Primer Plus-Cerasmart (7.88±3.90), Alloy Primer-Vita Enamic (7.90±2.14), and G Multi Primer-Katana Zirconia UTML (4.98±3.67).
CLINICAL SIGNIFICANCE
Failure of the restoration usually occurs at the weakest point in this three-element structure, thus correct primer selection according to material type is important. Additionally, for all CAD-CAM materials used in the study, Z-Prime Plus showed significantly greater adhesion strength than other systems so it may be more appropriate for use in clinics.
Topics: Resin Cements; Dental Bonding; Ceramics; Shear Strength; Materials Testing; Zirconium; Dental Stress Analysis; Surface Properties; Computer-Aided Design
PubMed: 38899993
DOI: No ID Found -
Journal of Materials Science. Materials... Jun 2024Orthopedic and dental implant failure continues to be a significant concern due to localized bacterial infections. Previous studies have attempted to improve implant...
Orthopedic and dental implant failure continues to be a significant concern due to localized bacterial infections. Previous studies have attempted to improve implant surfaces by modifying their texture and roughness or coating them with antibiotics to enhance antibacterial properties for implant longevity. However, these approaches have demonstrated limited effectiveness. In this study, we attempted to engineer the titanium (Ti) alloy surface biomimetically at the nanometer scale, inspired by the cicada wing nanostructure using alkaline hydrothermal treatment (AHT) to simultaneously confer antibacterial properties and support the adhesion and proliferation of mammalian cells. The two modified Ti surfaces were developed using a 4 h and 8 h AHT process in 1 N NaOH at 230 °C, followed by a 2-hour post-calcination at 600 °C. We found that the control plates showed a relatively smooth surface, while the treatment groups (4 h & 8 h AHT) displayed nanoflower structures containing randomly distributed nano-spikes. The results demonstrated a statistically significant decrease in the contact angle of the treatment groups, which increased wettability characteristics. The 8 h AHT group exhibited the highest wettability and significant increase in roughness 0.72 ± 0.08 µm (P < 0.05), leading to more osteoblast cell attachment, reduced cytotoxicity effects, and enhanced relative survivability. The alkaline phosphatase activity measured in all different groups indicated that the 8 h AHT group exhibited the highest activity, suggesting that the surface roughness and wettability of the treatment groups may have facilitated cell adhesion and attachment and subsequently increased secretion of extracellular matrix. Overall, the findings indicate that biomimetic nanotextured surfaces created by the AHT process have the potential to be translated as implant coatings to enhance bone regeneration and implant integration.
Topics: Surface Properties; Osteoblasts; Titanium; Animals; Dental Implants; Biomimetic Materials; Wettability; Cell Adhesion; Anti-Bacterial Agents; Materials Testing; Biomimetics; Humans; Cell Proliferation; Alloys; Prostheses and Implants; Coated Materials, Biocompatible; Nanostructures; Cell Survival; Alkaline Phosphatase; Hemiptera; Cell Line
PubMed: 38896291
DOI: 10.1007/s10856-024-06794-y -
Materials (Basel, Switzerland) May 2024The manufacturing of orthodontic archwires made from NiTi alloy has undergone numerous changes from the second half of the last century to modern times. Initially,... (Review)
Review
The manufacturing of orthodontic archwires made from NiTi alloy has undergone numerous changes from the second half of the last century to modern times. Initially, superelastic-active austenitic NiTi alloys were predominant, followed by thermodynamic-active martensitic NiTi alloys, and, finally, the most recent development was graded thermodynamic alloys. These advancements have been the subject of extensive investigation in numerous studies, as they necessitated a deeper understanding of their properties. Furthermore, it is imperative that we validate the information provided by manufacturers regarding these archwires through independent studies. This review evaluates existing studies on the subject with a specific focus on the Bio-active multi-force NiTi archwire, by examining its mechanical, thermal, and physicochemical properties before and after clinical use. This archwire consists primarily of Ni and Ti, with traces of Fe and Cr, which release graduated, biologically tolerable forces which increase in a front-to-back direction and are affected by the temperature of the environment they are in. The review provides information to practicing orthodontists, facilitating informed decisions regarding the selection and use of Bio-active™ archwires for individual patient treatments.
PubMed: 38893867
DOI: 10.3390/ma17112603 -
The Saudi Dental Journal Jun 2024This in vitro study aimed to evaluate the additive manufacturing (AM) of cobalt chromium Co-Cr and titanium Ti alloy clasps for clinical use. After scanning the Ni-Cr...
This in vitro study aimed to evaluate the additive manufacturing (AM) of cobalt chromium Co-Cr and titanium Ti alloy clasps for clinical use. After scanning the Ni-Cr die of the first molar, Akers' clasps were designed using computer-aided design/ computer-aided manufacturing (CAD/CAM). The clasps were manufactured from Co-Cr-W dental alloy and Ti-6Al-4V alloy powder using AM machines. Then, they were divided into two groups. The initial retentive force of the clasps was measured using a universal testing machine. Cyclic loading of the clasps was carried out by a specially designed insertion-removal testing apparatus in wet condition up to 5000 cycles. Retentive force was measured at 1000, 2000, 3000, 4000, and 5000 cycles. Moreover, the intaglio surface of each clasp was scanned using the scanner; and superimposition between the pre- and post-cycling clasp files was performed to evaluate deformation after cyclic loading. The fitting surfaces of retentive clasp tips were examined with a scanning electron microscope (SEM). Finally, it has been found that the initial retentive force for the Co-Cr group was 10.81 ± 0.37 N, and for the Ti group was 5.41 ± 0.18 N. Additionally, during the testing periods, both Co-Cr and Ti clasps continued to lose retentive force within the cycles of placement and removal. This effect was more prominent in the Co-Cr than in the Ti clasps. The distances between pre- and post-cycling in the retentive arm were -0.290 ± 0.11 mm and -0.004 ± 0.01 mm in Co-Cr and Ti alloys, respectively, and in the reciprocal arm were -0.072 ± 0.04 mm and -0.032 ± 0.04 mm in Co-Cr and Ti alloys, respectively. The retentive force required to remove the Ti clasps was found to be significantly lower than those required to dislodge the Co-Cr clasps. Co-Cr and Ti clasps lost significant amounts of retentive force from the initial use to the 3.5-year periods of simulated clinical use.
PubMed: 38883903
DOI: 10.1016/j.sdentj.2024.04.001