D. Raj Chordia

Bio: D. Raj Chordia is an academic researcher from College of Engineering, Guindy. The author has contributed to research in topics: Soft tissue & Randomized controlled trial. The author has an hindex of 1, co-authored 1 publications receiving 100 citations.

Comparison of the effectiveness of Gingival unit transfer and free Gingival graft in the management of localized Gingival recession - A systematic review

Abstract: Gingival Recession (GR) is defined as the displacement of the soft tissue margin apical to the cementoenamel junction which can lead to root exposure and hypersensitivity. Treatment of GR has become an important therapeutic issue due to the increasing number of cosmetic requests from patients. Several techniques exist for the management of GR that include Sub-Epithelial Connective Tissue Graft (SECTG), Pedicle Graft (lateral and coronal), and Free Gingival Graft (FGG) and more. FGG is a non-submerged grafting procedure carried out for the management of recession defects. However, FGG has limitations like aesthetic mismatch and bulky appearance. A relatively newer modification of FGG was introduced by Allen in 2004 wherein a palatal graft including the marginal gingiva and interdental tissue was used as donor tissue for recession coverage. This review aims to study and compare the use of Gingival Unit Graft/Transfer (GUG/GUT) (palatal graft including the marginal gingiva and papillae) and FGG in the management of GR.Randomized Clinical Trials, Non-Randomized Controlled Clinical Trials for the treatment of Miller Class I,II, and III of GRs by GUG with FGG were identified. Data sources included electronic databases and hand-searched journals. The primary outcome variables were complete root coverage, mean root coverage, vertical recession depth. The secondary outcome variables were keratinized tissue width gain, clinical attachment level and probing depth.Three Randomized Control Trials (RCTs) met the inclusion criteria and were evaluated in this systematic review. Both techniques showed significant improvement in clinical parameters. GUG procedure resulted in a greater percentage of sites achieving complete root coverage and vertical recession depth reduction when compared to FGG group in all the studies. Two studies reported significantly greater mean root coverage in GUG group compared to FGG group. GUG procedure revealed statistically significant greater gain in keratinized tissue width when compared to FGG group in all the studies.Because of the limited number of selected studies, no conclusive statement could be made regarding the advantage of the GUG technique over FGG. However, the percentage of sites with complete root coverage obtained in the GUG technique is higher than FGG. More RCTs with aesthetic and patient satisfaction-related parameters are needed to provide definite evidence.

Advanced cutting tools and technologies for drilling carbon fibre reinforced polymer (CFRP) composites: A review

Abstract: Carbon fibre reinforced polymer (CFRP) composites have excellent specific mechanical properties, these materials are therefore widely used in high-tech industries like the automobile and aerospace sectors. The mechanical machining of CFRP composites is often necessary to meet dimensional or assembly-related requirements; however, the machining of these materials is difficult. In an attempt to explore this issue, the main objective of the present paper is to review those advanced cutting tools and technologies that are used for drilling carbon fibre reinforced polymer composites. In this context, this paper gives a detailed review and discussion of the following: (i) the machinability of CFRP including chip removal mechanisms, cutting force, tool wear, surface roughness, delamination and the characteristics of uncut fibres; (ii) cutting tool requirements for CFRP machining; and (iii) recent industrial solutions: advanced edge geometries of cutting tools, coatings and technologies. In conclusion, it can be stated that advanced geometry cutting tools are often necessary in order to effectively and appropriately machine required quality features when working with CFRP composites.

Application of cutting fluids in machining of titanium alloys—a review

Abstract: Titanium alloys are widely used in aerospace, biomedical, and other engineering areas due to their superior properties. However, machining of titanium alloys has always been a challenge due to the high temperatures and tool wear rates. Dry machining has a limited range of permissible cutting conditions and is hence not suitable for industrial production. As a solution, flood cooling using cutting fluids is conventionally used to reduce the cutting temperatures. However, it is often discouraged in light of the associated environmental and health hazards. In order to achieve sustainable machining, different strategies for applying the cutting fluids are developed. Some of the prominent methods include minimum quantity lubrication (MQL), minimum quantity cooled lubrication (MQCL), and cryogenic cooling. This paper provides a comprehensive review of the available recent literature on such studies. Each of these techniques and results obtained in the studies has been discussed with emphasis on the advantages and limitations of each method. Major conclusions drawn are that coated carbides are better and machinability is greatly affected by the microstructure of the material. MQL certainly improved compared to other methods while cryogenic or super cooled cutting fluid application (MQCL) has been found to be better for specific situations. Use of nanofluids for titanium is not very popular among the researchers.