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Indian Journal of Dental Research :... Jan 2024The application of direct current can have a significant impact on the rate of tooth movement and surrounding periodontal ligament collagen turnover. This study aims to... (Comparative Study)
Comparative Study
An Immunohistochemical and Histological Study of the Animal Periodontal Ligament During Orthodontic Force Application with Concomitant Application of Electric Current - An Animal Study.
INTRODUCTION
The application of direct current can have a significant impact on the rate of tooth movement and surrounding periodontal ligament collagen turnover. This study aims to provide insight into the optimal characteristics of applied current to achieve enhanced tissue response.
METHOD
Eighteen male Wistar rats were divided into three groups (I, II, and III). Split mouth design was used, and each side was allocated into an experimental group or control group. Experimental sides of groups I, II, and III received 20, 10, and 15 μA of current (15 min, twice daily for 3 days). Both the experimental and control groups receive an orthodontic force via the NiTi closed coil spring. The amount of tooth movement was determined daily. Immunohistochemistry slides were scored using the immunoreactive scoring (IRS) system for collagen types I and III. One-way Analysis of Variance (ANOVA) and Tukey post hoc test were used to analyse the rate of tooth movement, while Mann-Whitney test was used to analyse IRS distribution between control and experimental groups.
RESULTS
Compared with the control group, there was a statistically significant difference in tooth movement in all the experimental groups, with group 3 showing the maximum rate on days 2 and 3. This was supported by immunoreactive scores for both collagen types I and III.
CONCLUSIONS
After 72 hours, the expression of collagen types 1 and 3 increased significantly for group III. This finding was in harmony with the rate of tooth movement, which was maximum for group 3 (15 μA) as compared to other groups.
Topics: Periodontal Ligament; Animals; Rats, Wistar; Tooth Movement Techniques; Male; Rats; Collagen Type I; Immunohistochemistry; Collagen Type III; Orthodontic Wires; Dental Alloys; Nickel; Stress, Mechanical; Titanium
PubMed: 38934753
DOI: 10.4103/ijdr.ijdr_905_22 -
Materials (Basel, Switzerland) Jun 2024This paper reports the results of our study on electrochemical polishing of titanium and a Ti-based alloy using non-aqueous electrolyte. It was shown that...
This paper reports the results of our study on electrochemical polishing of titanium and a Ti-based alloy using non-aqueous electrolyte. It was shown that electropolishing ensured the removal of surface defects, thereby providing surface smoothing and decreasing surface roughness. The research was conducted using samples made of titanium and TiAlV alloy, as well as implant system elements: implant analog, multiunit, and healing screw. Electropolishing was carried out under a constant voltage (10-15 V) with a specified current density. The electrolyte used contained methanol and sulfuric acid. The modified surface was subjected to a thorough analysis regarding its surface morphology, chemical composition, and physicochemical properties. Scanning electron microscope images and profilometer tests of roughness confirmed significantly smoother surfaces after electropolishing. The surface profile analysis of processed samples also yielded satisfactory results, showing less imperfections than before modification. The EDX spectra showed that electropolishing does not have significant influence on the chemical composition of the samples.
PubMed: 38930203
DOI: 10.3390/ma17122832 -
Journal of Functional Biomaterials Jun 2024In the original publication [...].
In the original publication [...].
PubMed: 38921543
DOI: 10.3390/jfb15060159 -
Journal of Functional Biomaterials Jun 2024The design of new, biomimetic biomaterials is of great strategic interest and is converging for many applications, including in implantology. This study explores a novel...
The design of new, biomimetic biomaterials is of great strategic interest and is converging for many applications, including in implantology. This study explores a novel approach to improving dental implants. Although endosseous TA6V alloy dental implants are widely used in oral implantology, this material presents significant challenges, notably the prevalence of peri-implantitis. Therefore, in this study, we investigate a new advance in the design of hybrid medical devices. This involves the design of a Ca-SZ coating deposited by PVD on a TA6V substrate. This approach aims to overcome the inherent limitations of each of these materials, namely TA6V's susceptibility to peri-implantitis on the one hand and zirconia's excessively high Young's modulus compared with bone on the other, while benefiting from their respective advantages, such as the ductility of TA6V and the excellent biocompatibility of zirconia, offering relevant prospects for the design of high-performance implantable medical devices. This study integrates characterisation techniques, focusing on the structural and elemental analysis of the Ca-SZ coating by XRD and TEM. The results suggest that this coating combines a tetragonal structure, a uniform morphology with no apparent defects, a clean interface highlighting good adhesion, and a homogeneous composition of calcium, predisposing it to optimal biocompatibility. All of these findings make this innovative coating a particularly suitable candidate for application in dental implantology.
PubMed: 38921529
DOI: 10.3390/jfb15060155 -
Cureus May 2024Introduction Fixed prosthodontic treatment involves the replacement of missing tooth structures with a variety of materials. Several newer metal-free ceramics have been...
Introduction Fixed prosthodontic treatment involves the replacement of missing tooth structures with a variety of materials. Several newer metal-free ceramics have been developed in recent years to meet patients' aesthetic needs. The long-term performance of all ceramics, however, is unknown, necessitating a continuous evaluation of the materials' strength. Aim The aim of this study was to compare and evaluate the fracture resistance of IPS E max pressable crowns and graphene crowns, which are luted with Rely X U200 self-adhesive resin cement on the respective dies, as well as thermocycling of IPS E max pressable crowns and thermocycling of graphene crowns. The current review was conducted as an in vitro examination at the Division of Prosthodontics, GSL Dental School, Rajahmundry, Andhra Pradesh, India. Materials and methods On a typodont tooth, a shoulder finish line design was prepared and incisal reduction was performed. The tooth was scanned, designed, and milled to produce 18 metal dies made of cobalt-chrome alloy. These metal dies produced a total of (n=36) all-ceramic crowns, which were divided into two groups based on crown type: 18 IPS E max crowns and 18 graphene crowns. The participants were once again divided into two subgroups within each group, with the purpose of assessing fracture resistance. This evaluation was conducted using a universal testing machine both before and after subjecting the specimens to thermocycling. The obtained data were sent for statistical analysis. Results Fracture resistance values were reduced after thermocycling of both IPS E max and Graphene crowns. Without thermocycling, the fracture resistance values of IPS E max crowns were higher than those of graphene crowns. Conclusions The fracture resistance of IPS E max crowns exhibited a statistically significant increase when compared to graphene crowns. Additionally, it was shown that the fracture resistance of both materials was reduced upon exposure to thermocycling.
PubMed: 38919249
DOI: 10.7759/cureus.61097 -
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 -
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 -
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