A bstract Aim: To quantify and compare the metal ions released from different bracket-wire combinations and to assess their cytotoxicity. Materials and Methods: A total of 360 fabricated sectional fixed orthodontic appliances were divided into 6 groups. The first three groups consisted of stainless-steel brackets with stainless-steel, snickel-titanium (NiTi), and titanium-molybdenum alloy (TMA) archwires, and the other three groups were fabricated using ceramic brackets (polycrystalline alumina) with stainless-steel, NiTi, and TMA archwires. These appliances were immersed in artificial saliva (pH 6.5 ± 0.5, 37°C), for 1 week, 2 weeks, and 1 month. The nickel and chromium ions released in the artificial saliva were quantified using a flame atomic absorption spectrometer, and cytotoxicity assessment was performed using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay on human cervical cancer cell line. Results: The stainless-steel bracket groups displayed a significantly greater release of nickel and chromium ions compared to the ceramic bracket groups ( P < 0.05). However, no significant differences were identified when comparing the three archwire types within the stainless-steel/ceramic bracket groups. At the end of 1 month, the % cell viability demonstrated by the appliances was in the decreasing order of stainless-steel-TMA > ceramic-stainless steel > stainless-steel-NiTi > ceramic-NiTi > stainless-steel-stainless steel > ceramic-TMA. Conclusion: Considerably greater release of nickel and chromium ions was observed from the appliances utilizing stainless-steel brackets compared to those employing ceramic brackets. However, no remarkable difference in the levels of nickel and chromium ions was observed when comparing the three archwires: stainless steel, NiTi, and TMA. In the cytotoxicity assessment, the ceramic-TMA combination displayed the highest level of cytotoxicity, while the stainless-steel-TMA combination displayed the least cytotoxicity.
Among various metal-based nanoparticles, silver nanoparticles (AgNPs) manifest superior inhibitory effects against several microorganisms. In fact, the AgNP-based treatment has been reported to inhibit both sensitive and resistant isolates of bacteria and other disease-causing microbes with equal propensity. Keeping this fact into consideration, we executed bio-mediated synthesis of AgNPs employing extract of flower and various other parts (such as bud and leaf) of the Hibiscus rosa-sinensis plant. The physicochemical characterization of as-synthesized AgNPs was executed employing transmission electron microscopy (TEM), dynamic light scattering (DLS), zeta potential, Fourier transform infrared (FTIR) spectroscopy, and UV-Vis spectroscopy, etc. The as-synthesized AgNPs demonstrated strong antimicrobial activity against both Gram-positive and Gram-negative bacteria with equal propensity. The as-synthesized AgNPs successfully inhibited Streptococcus mutans ( S. mutans ), one of the main causative bacteria responsible for dental caries. Considering the fact that orthodontic appliances facilitate infliction of the oral cavity with a range of microbes including S. mutans , we determined the growth inhibitory and anti-adherence activities of AgNPs on orthodontic appliances. We performed microbiological assays employing AgNPs adsorbed onto the surface of nickel–titanium (Ni-Ti) orthodontic wires. A topographic analysis of the decontaminated Ni-Ti orthodontic wires was performed by scanning electron microscopy. In addition to antimicrobial and anti-biofilm activities against oral S. mutans , the as-fabricated AgNPs demonstrated significant inhibitory and anti-biofilm properties against other biofilm-forming bacteria such as Escherichia coli and Listeria monocytogenes .
Quiz is a modality, which requires analytical skills to assess and apply information to crack the code of questions. The topic chosen for the Quiz was Cephalometrics, which is a clinical topic. It answers the diagnostic dilemma and is a must in ‘know-how’ syllabus of BDS final year students. For a better understanding of the topic, we need an interactive teaching session. It was observed that this Teaching-Learning (T-L) session assisted our students in remembering important concepts that are targeted by the quiz. Keywords: Quiz, Cephalometrics, Teaching-Learning techniques, Curriculum
Among various metal-based nanoparticles, silver nanoparticles (AgNPs) manifest superior inhibitory effect against several microorganisms. In fact, the AgNPs based therapy has been reported to inhibit both sensitive as well resistant isolates of bacteria and other disease causing microbes with equal propensity. Keeping this fact into consideration, we executed bio-mediated synthesis of AgNPs employing Hibiscus rosa sinensis flower extract. The as-synthesized AgNPs were evaluated for their potential to inhibit Streptococcus mutans (S. mutans), one of the main causative bacteria for dental caries. Beside several other reasons, orthodontic appliances have also been reported to facilitate infliction of oral cavity with a range of microbes including S. mutans. To determine the growth inhibitory and anti-adherence activity of AgNPs on orthodontic appliance, we performed microbiological assays employing AgNPs adsorbed on to the orthodontic wires. Topographic analysis of orthodontic wires was executed by scanning electron microscopy. In addition to antimicrobial and antibiofilm activity against oral S. mutans, the as-fabricated AgNPs demonstrated significant inhibitory and anti-biofilm properties against other biofilm forming bacteria such as Escherichia coli and Listeria monocytogenes as well.
With a better understanding of the molecular and cellular basis of orthodontic tooth movement now the focus is on surgically assisted rapid tooth movement This requires the collective effort of orthodontists and periodontists Clinically corticotomies and osteotomies have been devised to fasten the orthodontic tooth movement OTM Besides these this article highlights various newer methods of enhancing the rate of tooth movement like low level laser therapy use of electric current periodontal tissue activation by vibration photobiomodulation Pulsed electromagnetic fields etc Recent research has shown that these methods effectively increase the rate of OTM
AIMS:A new Resin Modified Glass Ionomer Cement known as nanoionomer containing nanofillers of fluoroaluminosilicate glass and nanofiller 'clusters' has been introduced. An in-vitro study aimed at evaluating shear bond strength (SBS) and adhesive remnant index (ARI) of nanoionomer under etching/unetched condition for use as an orthodontic bonding agent.MATERIAL AND METHODS:A total of 75 extracted premolars were used, which were divided into three equal groups of 25 each: 1-Conventional adhesive (Enlight Light Cure, SDS, Ormco, CA, USA) was used after and etching with 37% phosphoric acid for 30 s, followed by Ortho Solo application 2-nanoionomer (Ketac(™) N100, 3M, ESPE, St. Paul, MN, USA) was used after etching with 37% phosphoric acid for 30 s 3-nanoionomer was used without etching. The SBS testing was performed using a digital universal testing machine (UTM-G-410B, Shanta Engineering). Evaluation of ARI was done using scanning electron microscopy. The SBS were compared using ANOVA with post-hoc Tukey test for intergroup comparisons and ARI scores were compared with Chi-square test.RESULTS:ANOVA (SBS, F = 104.75) and Chi-square (ARI, Chi-square = 30.71) tests revealed significant differences between groups (P < 0.01). The mean (SD) SBS achieved with conventional light cure adhesive was significantly higher (P < 0.05) (10.59 ± 2.03 Mpa, 95% CI, 9.74-11.41) than the nanoionomer groups (unetched 4.13 ± 0.88 Mpa, 95% CI, 3.79-4.47 and etched 9.32 ± 1.87 Mpa, 95% CI, 8.58-10.06). However, nanoionomer with etching, registered SBS in the clinically acceptable range of 5.9-7.8 MPa, as suggested by Reynolds (1975). The nanoionomer groups gave significantly lower ARI values than the conventional adhesive group.CONCLUSION:Based on this in-vitro study, nanoionomer with etching can be successfully used as an orthodontic bonding agent leaving less adhesive remnant on enamel surface, making cleaning easier. However, in-vivo studies are needed to confirm the validity of present findings.
Newer cancer treatment modalities have increased patient survival rate and longevity. Craniofacial and dental abnormalities occurring after radiation therapy and surgery in cancer patients may lead to severe cosmetic or functional sequelae, which may require surgical or orthodontic intervention later on. We, present a case; who was treated for retinoblastoma with enucleation of left eye and external beam radiotherapy at 26 months of age. As a result of radiotherapy there was hypoplasia of the maxilla. This case validates Von-Limborg's theory that states that local epigenetic factor like the developing eye has an important influence on the growth of adjacent structures, as with this patient there was hypoplasia of left orbit. Certain dental anomalies were also seen in the maxillary arch.