Pre-COVID-19 knowledge, attitude and practice among nurses towards infection prevention and control in Bangladesh: A hospital-based cross-sectional survey.

INTRODUCTION: Hospital-acquired infections endanger millions of lives around the world, and nurses play a vital role in the prevention of these infections. Knowledge of infection prevention and control (IPC) best practices among nurses is a prerequisite to maintaining standard precautions for the safety of patients. AIM: The study aims to assess knowledge, attitudes, and practices (KAP) towards IPC including associated factors among the nurses of a tertiary care hospital in Bangladesh. METHODS: We conducted this hospital-based cross-sectional study from October 2017 to June 2018 at Dhaka Medical College Hospital among 300 nurses working in all departments. We calculated three KAP scores for each participant reflecting their current state of knowledge and compliance towards IPC measures. Descriptive, bivariate and multivariable analyses were conducted to determine KAP scores among nurses and their associated factors. RESULTS: Average scores for knowledge, attitudes, and practices were 18.6, 5.4, and 15.5 (out of 26, 7, and 24), respectively. The study revealed that the majority (85.2%) of the nurses had a good to moderate level of knowledge, half (51%) of them showed positive attitudes, and only one fifth (17.1%) of the nurses displayed good practices in IPC. The respondents' age, education, monthly income and years of experience were found to have statistical associations with having moderate to adequate level of KAP scores. Aged and experienced nurses were found more likely to have poor knowledge and unfavorable attitude toward IPC practices. CONCLUSION: The majority of nurses had good IPC knowledge, but their practices did not reflect that knowledge. In particular, nurses needed to improve the proper IPC practice for better patient care and to protect themselves. Regular IPC training and practice monitoring can enhance the IPC practice among nurses.

Influence of Thermocycling and Surface Treatments on the Flexural Strength of Denture Base Resin: An In Vitro Study.

AIM: The purpose of this study was to evaluate the flexural strength of heat polymerized denture base resin after thermocycling and different surface treatments done prior to repair or relining. MATERIALS AND METHODS: In this in vitro study, 80 specimens were made with heat-polymerized denture base resin and thermocycled (500 cycles between 5 and 55 °C). The specimens were divided in four groups based on different types of surface treatment: group I (control group: without surface treatment), group II (chloroform for 30 seconds), group III [methyl methacrylate (MMA) for 180 seconds], and group IV (dichloromethane for 15 seconds). The flexural strength was assessed using a Universal testing machine with three-point bending test. The obtained data were subjected to statistical analysis using one-way ANOVA and post-hoc tests. RESULTS: The values of average flexural strength of denture base resin measured were as follows: group I: 111.1 MPa, group II: 86.9 MPa, group III: 73.1 MPa, and group IV: 78.8 MPa. Groups II and IV possessed superior flexural strength than group III. The maximum values were observed with the control group. CONCLUSION: The flexural strength of heat-polymerized denture base resin gets affected by different surface treatments done prior to relining procedures. Lowest flexural strength was obtained when treated with MMA monomer for 180 seconds as compared to the other etchants used. CLINICAL SIGNIFICANCE: Prior to denture repair procedures, operators must choose the chemical surface treatment judiciously. It should not affect the mechanical properties such as flexural strength of denture base resins. Reduction in flexural strength of polymethyl methacrylate (PMMA) denture base can predispose the prosthesis to deteriorated performance when in function.

An in vitro study to evaluate the accuracy of orthopantomograph as an aid to determine condylar guidance.

PURPOSE: The study was conducted to evaluate the accuracy of orthopantomograph (OPG) as an aid to determine condylar guidance. METHODOLOGY: The condylar guidance was measured using the impressions of glenoid fossae and radiographs (OPG) on thirty dried human skulls. Frankfurt horizontal plane (FHP) was used as a reference plane in both the methods and wire markers were adapted to make the contours of glenoid fossae discernible for both the methods. The condylar inclination angle was measured between FHP and a line joining the most concave point on the glenoid fossa with the most inferior point on the articular eminence on both right and left sides. RESULTS: Pearson correlation was used for statistical analysis, and it showed a strong correlation between anatomic and radiographic methods (r = 0.864 for the left side, r = 0.873 for the right side) as well as between right and left sides (r = 0.830). The data were also subjected to regression analysis (linear and panel estimation approach) which showed that OPG could be effectively used to predict the condylar guidance (r2 = 0.6160). CONCLUSION: Although OPG shows a higher value than anatomic method, it can be used as an aid to set condylar guidance on semi-adjustable articulator.

A Comparative Evaluation of Effect of Reinforced Autopolymerizing Resin on the Flexural Strength of Repaired Heat-polymerized Denture Base Resin before and after Thermocycling.

AIMS AND OBJECTIVE: Denture fractures are a common problem in clinical practice. Despite the use of different reinforcement materials (metal wires, metal plates, and various types of fibers) for denture repairs, recurrent fractures are still common. The purpose of this study was to compare the maximum flexural loads of the heat-polymerized denture base resin when repaired with autopolymerizing resin reinforced with relatively smaller diameter metal wires and glass fibers, before and after thermocycling. MATERIALS AND METHODS: Heat polymerized rectangular specimens were fabricated and repaired with autopolymerized resin and different reinforcement materials. Stainless steel wires, coaxial wires, beta-titanium wires, and glass fibers were used as reinforcement materials. Metal wires were sandblasted before placing in the center of the specimen along with autopolymerizing resin. Control specimens were repaired without any reinforcements. Intact heat- and self-cure specimens were also prepared for comparison. Half of the specimens of each group were subjected to thermocycle stressing (5°C and 55°C, 30 s dwell time) for 2000 cycles. All the specimens, nonthermocycled as well as thermocycled, were then tested for flexural strength by using 3 point flexural test in Lloyd's Universal testing machine at 5 mm/min crosshead speed. The maximum flexural loads (N) for each specimen were recorded. The readings, thus obtained, were subjected to statistical analysis using two-way ANOVA and Tukey's multiple comparison test. RESULTS: The metal wire reinforcements increased the flexural strength of repaired specimens, whereas, glass fiber reinforcement produced slightly lower flexural strength when compared to those of control specimens, i.e., repair without any reinforcement. The highest flexural strength was demonstrated by specimens repaired with coaxial wire reinforcements (50.01 and 43.77 N before and after thermocycling, respectively). The increase in flexural strength with the use of stainless steel wire (45.12 and 41.56 N) and beta-titanium wire reinforcements (45.54 and 42.61N) was insignificant. CONCLUSIONS: Coaxial wire reinforcement produced significantly higher flexural loads than control. Increase in strength with stainless steel wire and beta-titanium wire was insignificant, whereas glass fiber reinforcement reduced the strength.

Rehabilitation of post-traumatic total nasal defect using silicone and acrylic resin.

Facial defects resulting from neoplasms, congenital abnormalities or trauma can affect the patient esthetically, psychologically, and even financially. Surgical reconstruction of large facial defects is sometimes not possible and frequently demands prosthetic rehabilitation. For success of such prosthesis, adequate replication of natural anatomy, color matching and blending with tissue interface are important criteria. Variety of materials and retention methods are advocated to achieve a functionally and esthetically acceptable restoration. Silicones are the most commonly used materials because of flexibility, lifelike appearance and ability to be used in combination with acrylic resin which is hard, provides body and helps in achieving retention to the prosthesis by engaging mechanical undercuts. Furthermore, the acrylic portion can be relined easily, thus helping comfortable wear and removal of the prosthesis by patient without traumatizing nasal mucosa. This case report describes time saving and cost effective prosthetic rehabilitation of a patient with total nasal defect using custom sculpted nasal prosthesis made up of silicone elastomer and acrylic resin, which is retained by engaging mechanical undercut and use of biocompatible silicone adhesive.

Comparative analysis of the retention of maxillary denture base with and without border molding using zinc oxide eugenol impression paste.

AIMS AND OBJECTIVES: The purpose of the study was to determine the effect of border molding on the retention of the maxillary denture base. MATERIALS AND METHODS: Two special trays, one with full extensions to the periphery and one 2 mm short from the borders were made on the cast obtained from the preliminary impression. Border molding was done on the tray which was short from borders. On both trays, the final impression was made with zinc oxide eugenol impression paste. Heat cure denture bases were fabricated on the prepared casts and retention was measured using specially designed instrument. OBSERVATIONS AND RESULTS: Mean force with border molding (2765.0 g) was larger than mean force without border molding (1805.0 g) at P < 0.01 level. In terms of percentage, too, the mean improvement (59.4%) in force of dislodgement was statistically highly significant (i.e. P < 0.01). CLINICAL SIGNIFICANCE: The results of the present study suggest that the dentures made with border molding will provide better retentive force than the dentures made without border molding.

Comparative evaluation of tensile bond strength of silicone-based denture liners after thermocycling and surface treatment.

PURPOSE: To examine, evaluate, and compare the tensile bond strength of two silicone-based liners; one autopolymerizing and one heat cured, when treated with different chemical etchants to improve their adhesion with denture base resin. MATERIALS AND METHODS: Hundred and sixty test specimens of heat-cured polymethyl methacrylate (PMMA) were fabricated; out of which 80 specimens were tested for tensile bond strength after bonding it to autopolymerizing resilient liner (Ufigel P) and rest 80 to heat-cured resilient liner (Molloplast B). Each main group was further divided into four subgroups of 20 specimens each, one to act as a control and three were subjected to surface treatment with different chemical etchants namely dichloromethane, MMA monomer, and chloroform. The two silicone-based denture liners were processed between 2 PMMA specimens (10 mm × 10 mm × 40 mm) in the space provided by a spacer of 3 mm, thermocycled (5-55°C) for 500 cycles, and then their tensile strength measurements were done in the universal testing machine. RESULTS: One-way ANOVA technique showed a highly significant difference in the mean tensile bond strength values for all the groups. The Student's t-test computed values of statistics for the compared groups were greater than the critical values both at 5% and at 1% levels. CONCLUSION: Surface treatment of denture base resin with chemical etchants prior to the application of silicone-based liner (Ufigel P and Molloplast-B) increased the tensile bond strength. The increase was the highest with specimens subjected to 180 s of MMA surface treatment and the lowest with control group specimens.

Prosthodontic management of temporomandibular disorders.

Temporomandibular disorders (TMD) are examined from a biopsychosocial or illness perspective. It is considered that TMD share features with many common chronic pain conditions. Functional disturbances of the masticatory system can be as complicated as the system itself. Although numerous treatments have been advocated, the complex nature of TMD requires a multidisciplinary team. Effective treatment selection begins with a thorough understanding of the disorder & its etiology. However, the multifactorial nature of this malady places some aspects of the disease beyond the traditional education of a Prosthodontist. The management goals for the Prosthodontist as a member of a TMD team are patient comfort, occlusal stability & the complex restoration of the teeth.

Evaluation of tensile bond strength of heat cure and autopolymerizing silicone-based resilient denture liners before and after thermocycling.

AIM: To assess the effect of simulated mouth conditions reproduced with thermocycling on the tensile bond strength of two silicone based resilient denture liners with acrylic resin bases. MATERIALS AND METHODS: Two silicone-based soft denture liners (Mollosil - Chairside autopolymerization and Molloplast B - Heat polymerization) were tested. For each liner, 30 specimens with a cross-sectional area of 10 Χ 10 mm and thickness 3 mm were processed between two acrylic blocks (Trevalon). Specimens were divided into a control group that was stored for 24 hours in water at 37°C and a test group that was thermocycled (2500 cycles) between baths of 5° and 55°C. Tensile bond strength (kg/cm²) was determined in a universal testing machine using crosshead speed of 5 mm/min. STATISTICAL ANALYSIS USED: The student t-test was used to determine the significance of the difference in bond strength between the two liners. RESULTS: The mean tensile bond strength for control and thermocycled specimens of the two liners were: Mollosil (6.82 kg/cm² and 8.41 kg/cm²) and Molloplast-B (16.30 kg/cm² and 13.67 kg/cm²), respectively. Comparison of bond strength of control specimens with thermocycled specimens of the liners indicated a significant difference for both Mollosil (P=0.045) and Molloplast-B (P=0.027). Comparison between control specimens of both liners and thermocycled specimens of both liners indicated a highly significant difference (P<0.001). CONCLUSIONS: Heat polymerized resilient denture liner Molloplast-B had higher tensile bond strength than autopolymerizing liner Mollosil regardless of thermocycling. The bond strength of Mollosil increased after thermocycling while that of Molloplast-B decreased after thermocycling. CLINICAL IMPLICATIONS: Although heat-polymerized denture liners require more processing time than autopolymerizing liners, but they display much better adhesion properties to denture base resin and should thus be preferred when soft liner has to be used for a longer duration of time.

Comparison of bond strength of auto polymerizing, heat cure soft denture liners with denture base resin - An In Vitro study.

Optimum bond strength between denture soft liner and denture base resin is very important for the success of any denture prosthesis. The tensile bond strength of two commercially available silicone-based heat cured (Molloplast B) and auto polymerizing (Mollosil) was compared with denture base material (trevalon). Molloplast B-trevalon bond in both un-polymerized (dough stage) and already polymerized forms were also compared. Lloyds Universal testing machine was used to test 60 samples. Molloplast B bond strength was greater than Mollosil soft denture liner; it was even greater when packed against trevalon in an un-polymerized form than an already polymerized trevalon using primo adhesive. Both the soft lining materials used are acceptable for clinical usage.