Manisha Khanna - Academia.edu (original) (raw)

Papers by Manisha Khanna

eJournal of oral & maxillofacial research, Mar 31, 2024

The purpose of this comparative study in vitro was to evaluate the effect of organic and inorgani... more The purpose of this comparative study in vitro was to evaluate the effect of organic and inorganic nanoparticles on colour stability, tear strength and hardness of maxillofacial silicone elastomer at baseline and when subjected to outdoor weathering for 6 months. Material and Methods: A total of 240 specimens were fabricated using M511 platinum silicone which were divided into total 4 groups (n = 60) based on the type of nanoparticles (control, polytetrafuoroethylene [PTFE], titanium dioxide [TiO 2 ], zinc oxide [ZnO]) added and each group was further divided into 3 subgroups (n = 20) for colour, tear strength (TS) and hardness (H) testing. The tests were conducted and data was obtained both before and after outdoor weathering of 6 months. Results: Minimum colour change after weathering was observed in PTFE group (∆E = 2.23). TiO 2 group showed maximum TS (12.01 N/mm) followed by PTFE group (10.85 N/mm) before weathering. After weathering, maximum TS was shown by TiO 2 group (12.9 N/mm) and PTFE group (12.54 N/mm). TiO 2 group showed maximum hardness (24.15 shore A) before weathering and PTFE group showed maximum hardness (33.43 shore A) after weathering. Conclusions: Within the limitations of this study, it can be concluded that the addition of polytetrafuoroethylene nanoparticles to the polymer enhances both the optical as well as mechanical properties and can be considered favourable for the extended life of the prosthesis.

International Journal of Prosthodontics and Restorative Dentistry

Purpose: Commercially available stock trays do not usually fit the arch form and are relatively f... more Purpose: Commercially available stock trays do not usually fit the arch form and are relatively flat in dimensions, leading to a compromised impression and prosthesis. So, the purpose of this study was to categorize resorbed mandibular ridges according to arch width and sulcus depth and formulation of stock tray design conforming to different resorbed ridge forms. Materials and methods: Measurements on master casts of completely edentulous resorbed ridges (n = 280) were done using a digital vernier caliper. Cluster analysis of means of anterior and posterior arch width and posterior alveololingual sulcus (ALS) depth was done to categorize the extremely resorbed residual ridges for the formulation of conforming stock trays. Cluster analysis formulated three categories. Category 1 had a mean anterior arch width of 23 mm, posterior arch width of 50 mm, and posterior ALS depth of 5.5 mm. Respective dimensions in category 2 were 31, 58, and 12 mm, and in category 3 were 27, 55, and 8.7 mm. Means of arch length, ridge width, sulcus depth, and retromolar pad (RMP) angle were used to modify tray flange dimensions. One-way analysis of variance (ANOVA) for K-means and multiple Tukey honestly significant difference (HSD) tests were applied for validation of clusters/categories. Results: Significant p-values in one-way ANOVA for K-means cluster (p < 0.001) and multiple Tukey HSD test (p < 0.001) validated categorization of extremely resorbed mandibular residual ridges in the study. Mean values of other parameters were used to modify the tray flanges. The 135° angle of the RMP with residual resorbed ridge was suggested to be incorporated in trays to accommodate higher angles too. Conclusion: Use of the formulated stock trays, will improve their adaptation to the resorbed mandibular edentulous ridges and hence the primary impression making, which will provide a strong foundation for a successful final complete denture in such patients.

Dental Journal of Advance Studies

Orbital mucormycosis was the second most common type of mucormycosis during the COVID-19 wave, wh... more Orbital mucormycosis was the second most common type of mucormycosis during the COVID-19 wave, which along with the loss of orbital content, lead to a loss of confidence in the patients as well. Prosthodontists play a major role in rehabilitating the lost structure as well as the lost confidence in the patients by providing extra-oral silicone prosthesis. Shade matching of maxillofacial silicone elastomer is one vital step during fabrication of the prostheses. Available literature does not yet describe the procedure of shade matching and extrinsic layering of silicone prosthesis in detail. This article presents a case report of a 45-year-old male patient who presented with a healed surgical site of exenterated orbit due to mucormycosis and complained of disfigurement of the face. A customized silicone orbital prosthesis was fabricated for the patient. The present case report critically focused on color matching during silicone manipulation and extrinsic layering after curing the prosthesis.

CERN European Organization for Nuclear Research - Zenodo, Aug 29, 2022

Casting 3-D printing (DMLS) Milling Material that can be used for the technique Alloys like CO-Cr... more Casting 3-D printing (DMLS) Milling Material that can be used for the technique Alloys like CO-Cr, metal like Ti Metals like Ti, Co-Cr Metal like Ti and metal free substitute like Zirconia and BioHPP*

eJournal of oral & maxillofacial research, Mar 31, 2024

The purpose of this comparative study in vitro was to evaluate the effect of organic and inorgani... more The purpose of this comparative study in vitro was to evaluate the effect of organic and inorganic nanoparticles on colour stability, tear strength and hardness of maxillofacial silicone elastomer at baseline and when subjected to outdoor weathering for 6 months. Material and Methods: A total of 240 specimens were fabricated using M511 platinum silicone which were divided into total 4 groups (n = 60) based on the type of nanoparticles (control, polytetrafuoroethylene [PTFE], titanium dioxide [TiO 2 ], zinc oxide [ZnO]) added and each group was further divided into 3 subgroups (n = 20) for colour, tear strength (TS) and hardness (H) testing. The tests were conducted and data was obtained both before and after outdoor weathering of 6 months. Results: Minimum colour change after weathering was observed in PTFE group (∆E = 2.23). TiO 2 group showed maximum TS (12.01 N/mm) followed by PTFE group (10.85 N/mm) before weathering. After weathering, maximum TS was shown by TiO 2 group (12.9 N/mm) and PTFE group (12.54 N/mm). TiO 2 group showed maximum hardness (24.15 shore A) before weathering and PTFE group showed maximum hardness (33.43 shore A) after weathering. Conclusions: Within the limitations of this study, it can be concluded that the addition of polytetrafuoroethylene nanoparticles to the polymer enhances both the optical as well as mechanical properties and can be considered favourable for the extended life of the prosthesis.

International Journal of Prosthodontics and Restorative Dentistry

Purpose: Commercially available stock trays do not usually fit the arch form and are relatively f... more Purpose: Commercially available stock trays do not usually fit the arch form and are relatively flat in dimensions, leading to a compromised impression and prosthesis. So, the purpose of this study was to categorize resorbed mandibular ridges according to arch width and sulcus depth and formulation of stock tray design conforming to different resorbed ridge forms. Materials and methods: Measurements on master casts of completely edentulous resorbed ridges (n = 280) were done using a digital vernier caliper. Cluster analysis of means of anterior and posterior arch width and posterior alveololingual sulcus (ALS) depth was done to categorize the extremely resorbed residual ridges for the formulation of conforming stock trays. Cluster analysis formulated three categories. Category 1 had a mean anterior arch width of 23 mm, posterior arch width of 50 mm, and posterior ALS depth of 5.5 mm. Respective dimensions in category 2 were 31, 58, and 12 mm, and in category 3 were 27, 55, and 8.7 mm. Means of arch length, ridge width, sulcus depth, and retromolar pad (RMP) angle were used to modify tray flange dimensions. One-way analysis of variance (ANOVA) for K-means and multiple Tukey honestly significant difference (HSD) tests were applied for validation of clusters/categories. Results: Significant p-values in one-way ANOVA for K-means cluster (p < 0.001) and multiple Tukey HSD test (p < 0.001) validated categorization of extremely resorbed mandibular residual ridges in the study. Mean values of other parameters were used to modify the tray flanges. The 135° angle of the RMP with residual resorbed ridge was suggested to be incorporated in trays to accommodate higher angles too. Conclusion: Use of the formulated stock trays, will improve their adaptation to the resorbed mandibular edentulous ridges and hence the primary impression making, which will provide a strong foundation for a successful final complete denture in such patients.

Dental Journal of Advance Studies

Orbital mucormycosis was the second most common type of mucormycosis during the COVID-19 wave, wh... more Orbital mucormycosis was the second most common type of mucormycosis during the COVID-19 wave, which along with the loss of orbital content, lead to a loss of confidence in the patients as well. Prosthodontists play a major role in rehabilitating the lost structure as well as the lost confidence in the patients by providing extra-oral silicone prosthesis. Shade matching of maxillofacial silicone elastomer is one vital step during fabrication of the prostheses. Available literature does not yet describe the procedure of shade matching and extrinsic layering of silicone prosthesis in detail. This article presents a case report of a 45-year-old male patient who presented with a healed surgical site of exenterated orbit due to mucormycosis and complained of disfigurement of the face. A customized silicone orbital prosthesis was fabricated for the patient. The present case report critically focused on color matching during silicone manipulation and extrinsic layering after curing the prosthesis.

CERN European Organization for Nuclear Research - Zenodo, Aug 29, 2022

Casting 3-D printing (DMLS) Milling Material that can be used for the technique Alloys like CO-Cr... more Casting 3-D printing (DMLS) Milling Material that can be used for the technique Alloys like CO-Cr, metal like Ti Metals like Ti, Co-Cr Metal like Ti and metal free substitute like Zirconia and BioHPP*