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Background: The black fungus, mucormycosis, is on the list of lethal complications reported in recent times in COVID patients. Methodology: This cross-sectional study included all cases of post-COVID-19 mucormycosis. Patients' demographics, clinical presentations, and general health information were collected using a pre-designed form. Results: The study included 171 participants with the mean (SD) age as 49 (10) years with the sex distribution as 71% (122/171) male and 29% (49/122) females. About half of the admitted patients (47%) were known cases of Diabetes Mellitus type II with a median (IQR) Glycosylated Haemoglobin (HbA1c) of 9.1% (7-11.1%). Only 28% (48/171) had received the first COVID vaccination, and 2.9% (5/171) were fully vaccinated with two doses. During COVID-19, 76% (130/171) required hospitalisation for a mean (SD) stay of 11 (6.4) days. Eighty percent of the patients (136/171) received steroids during therapy, while 87% (150/171) and 51% (88/171) received antibiotics and antivirals, respectively. Oxygen was administered to 71% of hospitalised patients (120/171), with 39.1% (47/120) receiving it for more than 7 days. About the development of the first symptoms of mucormycosis (headache, nasal congestion, black crusts in the nose, facial pain, swelling in cheeks and eyes, and loss of vision) after being diagnosed with COVID-19, 16% (28/171) reported it within 7 days, 75% (127/171) between 8 and 30th days and 9% (16/171) after a month. On examination, 20% of mucor patients had hard palate findings, eschars, fistulas, and perforations, 38% had periodontal abscesses, and 5% reported tenderness to percussion. Conclusion: Generally, oral manifestations involved the palate and included varying degrees of mucosal discolouration, swelling, ulcers, superficial necrotic areas, and bone exposure and necrosis with dark eschars.
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Purpose: Polymethylmethacrylate denture bases are prone to fracture, so reinforcement of dentures with nanoparticles is required to overcome these challenges. This invitro study was done to assess the effect of reinforcement with nanoparticles of polyetheretherketone (PEEK), zirconium oxide (ZrO2) and its mixture on flexural strength of polymethylmeythacrylate resin. Materials and methods: A total of 60 acrylic resin specimens measuring 65 mm × 10 mm × 2.5 mm were fabricated. The specimens were divided in to fifteen specimens in each group [control group (C), 3wt% PEEK group (P), 3wt% zirconia group (Z), and hybrid reinforcement of 1.5wt% PEEK and 1.5wt% ZrO2 group (P-Z)]. The flexural strength of the specimens was evaluated using a three-point bending test on a universal testing machine. The statistical analysis was done using one-way analysis of variance (ANOVA), and the intergroup comparison was done using Tukey's post hoc analysis. Results: The mean flexural strength was maximum in group P-Z (98.73MPa) followed by group P (86.22 MPa) and group Z (84.48 MPa). The mean flexural strength was least in the control group (74.86MPa). One-way ANOVA revealed a highly significant (P<0.01) difference among the groups. Pairwise comparison among groups showed a significant difference (P<0.05) among all the groups except in between groups P and Z where no significant difference was found (P=0.406). Conclusion: Hybrid reinforced PEEK and zirconia could be used as an effective reinforcement material for denture base resin. The hybrid PEEK and zirconia reinforced resin can be an alternative treatment option in patients with heavy occlusal forces and for patients who have previous experience of multiple denture fractures.
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PURPOSE: This in vitro study was done to compare the flexural strength of polymethyl methacrylate resin reinforced with multiwalled carbon nanotubes (MWCNTs) and processed by conventional water bath technique and using microwave energy. MATERIALS AND METHODS: A total of 180 acrylic resin specimens measuring 65 mm × 10 mm × 2.5 mm were fabricated, with conventional water bath groups and microwave group having ninety specimens each. Ninety specimens were divided into thirty specimens as control and subgroups containing 0.025% MWCNTs and 0.050% MWCNTs with thirty specimens each. The specimens were tested for flexural strength by three-point bending test on universal testing machine. The statistical analysis was done using Student's t-test and one-way analysis of variance, and the intercomparison between each group was done using Tukey's post hoc analysis. RESULTS: The mean flexural strength of specimens cured by water bath technique was 95.563 MPa and microwave technique was 118.416 MPa. Control Group B possesses highly significant increase in flexural strength than Control Group A with P < 0.01. Unpaired Student's t-test showed that Subgroup B1 and Subgroup B2 possess highly significant increase in flexural strength than Subgroup A1and Subgroup A2. CONCLUSION: Heat polymerized denture base resin with and without reinforcement of MWCNTs and polymerized by microwave technique possess higher flexural strength than heat polymerized fiber reinforced denture resin polymerized by water bath technique. MWCNTs could be used as an effective reinforcement material for denture base resin polymerized by either water bath technique or microwave energy.
RESUMO
BACKGROUND: Acrylic teeth have long been used in the treatment of a complete denture. One of the primary advantages of acrylic teeth is their ability to adhesively bond to the denture base resins. Although the bonding seems satisfactory, however, bond failures at the acrylic teeth and denture base resin interface are still a common clinical problem in prosthodontics. The purpose of this study was to evaluate the bond strength of acrylic teeth to denture base using different polymerizing techniques. MATERIALS AND METHODS: Acrylic resin teeth were bonded to heat cure acrylic resin and were polymerized by conventional water bath and microwave energy. The samples are then retrieved from the flask; trimmed and polished. The samples were then subjected to tensile forces till failure by using the Instron Universal testing machine. The machine used a direct pull on the incisal portion of the lingual surface in a labial direction at a height above the denture base resin bar with a crosshead speed of 0.5 mm/min. RESULTS: In the present study, it was found that conventionally cured specimens exhibited higher bond strength than microwave cured specimens and majority of fractures occur within the body of the tooth. It was found that debonding occurs within the body of the tooth rather than tooth acrylic interface, so there is no need of surface treatment of ridge lap surface. CONCLUSION: Conventionally cured specimens possess statistically higher bond strength than microwave cured specimens.
