Effect of Fluoride Prophylactic Agents on the Surface Topography of NiTi and CuNiTi Wires

Aim: The aim of this study was to see the effect of topical fluoride on surface texture on nickel-titanium and copper-nickel-titanium orthodontic archwires. Materials and methods: Preformed rectangular NiTi and CuNiTi wires were immersed in in fluoride solution and artificial saliva (control) for 90 minutes at 37°C. after immersion optical microscope was used to see the fluoride effect on the wire topography. Results: The acidulated fluoride agents appeared to cause greater corrosive effects as compared to the neutral fluoride agents. Conclusion: The result suggest that using topical fluoride agents leads to corrosion of surface topography indirectly affecting the mechanical properties of the wire that will lead to prolonged orthodontic treatment. Clinical significance: The use of topical fluoride agents has to be limited in patients with prolonged orthodontic treatment as it causes the corrosion of the NiTi and CuNiTi wires. Keywords: NiTi, CuNiTi, Fluoride agents, Optical microscope. How to cite this article: Mane PN, Pawar R, Ganiger C, Phaphe S. Effect of Fluoride Prophylactic Agents on the Surface Topography of NiTi and CuNiTi wires. J Contemp Dent Pract 2012;13(3):285-288. Source of support: Nil Conflict of interest: None declared.     

A retrospective analysis of early experience with modified complete primary repair of exstrophy bladder (CPRE) in neonates and children

Objective:

To study the problems faced during the surgery and follow-up of modified complete primary repair of exstrophy (CPRE) technique. Initial experience with CPRE and its short- and long-term outcomes with respect to continence status and psychosocial impact are reported.

Materials and Methods:

A retrospective review of the hospital case records from March 2008 to September 2012 was performed. Data of patients with bladder exstrophy managed by a single paediatric surgeon using modified CPRE technique were analysed. Quality of life and psychosocial impact of the surgery were assessed using Pediatric Quality of Life Inventory (PedsQL 4.0) and compared with those of typical peers.

Results:

Eight children (age 4 days-12 years) underwent CPRE using modified Mitchell''s technique. Two patients (25%) experienced early postoperative complications, with infection and fistula developing in one each. All the patients were doing well on follow-up, with variable continence rates and good cosmesis. Mean duration of follow-up was 18.5 months (range 6 months-4 years). Five out of seven (71%) children were continent or partially continent. One case was lost to follow-up. PedsQL scores were comparable with those of age-matched peers in all domains except the social functioning domain in 8-12 years age group (83.53 ± 9.70 vs. 77.86 ± 10.22, P < 0.05).

Conclusion:

Our preliminary results with modified CPRE in neonates and children have been encouraging. No major complications were observed. Continence rate was satisfactory and cosmetic results were good. Though the technique is being practiced at several Indian centres, there is a paucity of comprehensive Indian data on CPRE.KEY WORDS: Bladder exstrophy, complete primary repair, urinary continence     

Evaluation of treatment of calcaneal fractures with a modified approach in a peripheral setting: a cost-effective model

Background

We present the results of open reduction and internal fixation of intra-articular calcaneal fractures with Kirschner wires with some modifications.

Material and methods

A longitudinal study was done on 37 patients who had fallen from certain heights; the study subjects were predominantly construction workers. Forty-seven fractures of the study subjects were treated using a modified approach that includes incision and some tips in operative technique. Details of modification and their evaluation on the basis of restoration of heel shape with special attention to the lateral wall, radiological assessment of Bohler’s angle, varus and valgus movement of the heel, pain while walking, patient satisfaction assessment upon return to pre-injury work are elaborated in this paper. Duration of study was from January 2000 to May 2011.

Results

The fractures healed well with good radiological and functional outcomes, and patients returned to pre-injury work status in 4–6 months.

Conclusion

The need to change to the Kocher approach for the treatment of calcaneal fracture with right-angled incision and elevation of the lateral flap is not necessary if the surgical tips showed in this paper are followed meticulously to achieve a good soft tissue outcome initially and, eventually, a good bony radiological and functional outcome. As implants used are very cheap and affordable to workers of low socioeconomic status, the authors have developed this method and presently believe that this method is best for all classes of patients with the said problem.     

Influence of Test Conditions on Sliding Wear Performance of High Velocity Air Fuel-Sprayed WC–CoCr Coatings

Sliding wear performance of thermal spray WC-based coatings has been widely studied. However, there is no systematic investigation on the influence of test conditions on wear behaviour of these coatings. In order to have a good understanding of the effect of test parameters on sliding wear test performance of HVAF-sprayed WC–CoCr coatings, ball-on-disc tests were conducted under varying test conditions, including different angular velocities, loads and sliding distances. Under normal load of 20 N and sliding distance of 5 km (used as ‘reference’ conditions), it was shown that, despite changes in angular velocity (from 1333 rpm up to 2400 rpm), specific wear rate values experienced no major variation. No major change was observed in specific wear rate values even upon increasing the load from 20 N to 40 N and sliding distance from 5 km to 10 km, and no significant change was noted in the prevailing wear mechanism, either. Results suggest that no dramatic changes in applicable wear regime occur over the window of test parameters investigated. Consequently, the findings of this study inspire confidence in utilizing test conditions within the above range to rank different WC-based coatings.     

Homoduplex to i-motif structural switch exhibited by a cytosine rich strand of the MYH7 heavy chain β gene promoter at physiological pH

Genomic locations such as promoter, exon, intron, telomeric and non-telomeric regions are rich in GC-rich sequences with the potential to form G- and C-tetraplexes on both strands independently. Herein, we employed biophysical and biochemical methods to study a 34-mer C-rich DNA sequence of the myosin heavy chain β gene (MYH7β) promoter, namely HM34C for humans and the rabbit counterpart, RM34C, which differs from HM34C at three positions (three bases). Circular dichroism (CD), UV-thermal denaturation and native gel electrophoresis studies demonstrated that both the C-rich promoter segments form C-tetraplex (i-motif) structures. The CD studies revealed that HM34C forms the i-motif structure at acidic pH (5.2) in the presence of 0.1 M NaCl but remains unstructured at physiological pH. Interestingly, RM34C can form the stable i-motif structure in acidic as well as physiological pH. A shift in the positive peak from 280 nm to 275 nm with the increase in temperature from 4 °C to 30 °C was observed in temperature-dependent CD studies. UV-melting studies showed a biphasic transition for RM34C, indicating the existence of two structural species at neutral pH. In view of these findings we suggest that at physiological pH, the RM34C sequence exists in equilibrium between two structural motifs, i.e. the i-motif and homoduplex structure. This study may add to the understanding of the i-motif/homoduplex in equilibrium in physiological environments.

Genomic locations such as promoter, exon, intron, telomeric and non-telomeric regions are rich in GC-rich sequences with the potential to form G- and C-tetraplexes on both strands independently.     

Effects of Stocking Density on Growth Performance,Survival and Production of Catla catla and Labeo rohita During Nursery Rearing in Cages

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - A nursery rearing experiment of fry to fingerling was conducted in cages in Dimbhe reservoir of Pune District...