ABSTRACT
In this work, carbonaceous nanoparticles (NPs) of varying morphology, viz., multilayer graphene (lamellar, thickness â¼ 3-7 nm), graphite (spherical â¼70 nm), and multi-walled carbon nanotubes (tubular), were selected to explore their tribo-potential in oil under identical operating conditions. A series of nano-oils were prepared using API group III mineral base oil with a dispersant (1%) and selected NPs in incremental concentration (0.5-4%). The tribo-performance of oils was evaluated on a four-ball tester and SRV-IV for extreme-pressure, antiwear (AW), and antifriction performance. Formulations were characterized for density, viscosity, and viscosity index. The stability of oils was monitored through visual observation weekly. Results revealed that the graphene particles showed excellent wear-preventive ability as an AW additive with (41-50) % increase followed by nanographite. Worn surfaces were studied to understand the plausible wear mechanism using a different spectroscopic technique. Tribo-behavior performance was supported with lateral force microscopy on the surfaces of tribo-films.
ABSTRACT
INTRODUCTION: The temporo-mandibular joint (TMJ) is a complex anatomical structure that is concerned with mastication, deglutition, and speech. Ankylosis of the TMJ occurs when the condyle gets fused to glenoid fossa by bony or fibrous tissue. It is an incapacitating problem, commonly occurring in children and is usually associated with trauma or infection. MATERIALS AND METHODS: A total of ten patients with written informed consent having TMJ ankylosis (unilateral/bilateral) fulfilling the inclusion criteria were selected for the study and were operated under general anaesthesia with arthrectomy followed by reconstruction of ramal condylar unit with SCG (Group I) or CCG (Group II). Pre-operative and post-operative evaluation assessments were done at regular intervals for maximum mouth opening, range of mandibular movements, and height of ramus. RESULTS: Statistical analysis shows that the increase in maximum mouth opening was found 1.1% higher in Group II (75.9%) as compared to Group I (74.9%). The increase in lateral excursion at affected side was found 1.3% higher in Group I (84.6%) as compared to Group II (83.3%). The increase in lateral excursion at non-affected side was found 10.3% higher in Group I (76.9%) as compared to Group II (66.7%). The increase in protrusive movement was found 17.5% higher in Group II (88.9%) as compared to Group I (71.4%). Six months post-operative height of ramus was found 10.5% higher in Group II as compared to Group I. CONCLUSION: The present study concludes the superiority of costochondral graft over sternoclavicular graft in terms of growth and function. Continued deliberation between the two grafts with larger sample size and a longer follow-up with multicentric consensus will be required to draw definitive indications of the two grafts.
