Elżbieta Mierzwińska-Nastalska

Significance of polymethylmethacrylate (PMMA) modification by zinc oxide nanoparticles for fungal biofilm formation

The objective of this study was to obtain a material composite with antifungal properties for dentures to be used as an alternative protocol in denture stomatitis treatment and prevention. Denture stomatitis is still a clinical problem in patients particularly vulnerable to this disease. Composites of PMMA and doped ZnO-NPs (weight concentrations, 2.5%, 5%, 7.5%) and PMMA with sprayed solvothermal and hydrothermal ZnO-NPs were tested. The following investigations of newly formed biomaterials were undertaken: influence on Candida albicans solution, biofilm staining, XTT analysis and a quantitative analysis of adhered C. albicans. These studies evidenced the antifungal activity of both nanocomposites PMMA-ZnO-NPs and the efficacy of sputtering of zinc oxide nanoparticles on the PMMA. The study of the biofilm deposition on the surface showed that antifungal properties increase with increasing concentration of ZnO-NPs. The XTT assay in conjunction with testing the turbidity of solutions may indicate the mechanism by which ZnO-NPs exert their effect on the increased induction of antioxidative stress in microorganism cells. The denture base made of the aforesaid materials may play a preventive role in patients susceptible to fungal infections. Based on the results obtained a modified treatment of stomatitis Type II (Newtons classification) complicated by fungal infection was proposed.

Influence of Denture Plaque Biofilm on Oral Mucosal Membrane in Patients with Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) have the lower airways colonized with pathogenic bacteria in a stable period of the disease and during exacerbations. The etiology of bacterial exacerbations of COPD depends on the underlying disease, the frequency of exacerbations and antibiotic therapy. Microorganisms can be aspirated off the denture plaque biofilm into the lower respiratory tract and could reduce the patients immunity and cause pneumonia. COPD patients, who are using acrylic dentures in oral cavity, are exposed to denture stomatitis and oral candidiasis. The aim of this study was to establish the composition of denture plaque biofilm and its impact on the oral mucosa in COPD patients. The study included patients in a stable phase of COPD using removable denture and the control group included healthy wearers appliances. Examinations concerned the oral mucosal membrane and the hygienic condition of prosthetic restorations. Microbiological examinations were performed by taking a direct swab from the surface of acrylic dentures. Seventeen bacterial and fungal strains were isolated from denture plaque of COPD patients, which could be a reservoir of pathogens in the upper and lower airways. The results showed a greater frequency of prosthetic stomatitis complicated by mucosal infections among COPD patients compared to healthy subjects.

Diagnosis of Invasive Pulmonary Aspergillosis

Culturing strains from clinical samples is the main method to diagnose invasive pulmonary aspergillosis. Detecting the galactomannan antigen in serum samples is an auxiliary examination. The goal of this study was to determine the frequency with which Aspergillus fumigatus was cultured in clinical samples taken from patients hospitalized in the the Infant Jesus Teaching Hospital in Warsaw, Poland, in the period of 2013-2014. Specimens from the respiratory tract and blood were cultured for mycological and serological assessments. Strain isolation was performed in chloramphenicol Sabouraud agar. Species identification was based on morphological traits in macro-cultures and on microscopic examination. The galactomannan antigen was detected by ELISA method. Out of 2000 clinical samples with positive mycological results, 200 were obtained from the respiratory tract. A. fumigatus was cultured in 13 cases from the respiratory group. Ten cases were cultured out of tracheal aspirates and three from bronchoalveolar lavage fluid. The galactomannan antigen was detected in a serum sample from only one out of the 13 patients with cultures positive for A. fumigatus. It also was detected in serum samples of three other patients in whom A. fumigatus culture yielded a negative result. We conclude that culture-confirmed invasive pulmonary aspergillosis represents a scarce finding. A. fumigatus cultured from clinical samples may not always be confirmed by ELISA assay and vice versa a positive ELISA result does not attest the successful culture.

Preparation and characterization of ZnO-PMMA resin nanocomposites for denture bases

PURPOSE The aim of the paper was to investigate the antifungal activity of zinc oxide nanoparticles (ZnONPs) against Candida albicans. Some attempts have been made to find out the best way to introduce ZnONPs into polymethyl methacrylate (PMMA) resin material and to determine some parameters of a newly formed composite. MATERIAL AND METHODS Zinc oxide nanoparticles were manufactured and their basic physical parameters were determined (average particle size, density, specific surface area). Minimal inhibitory concentration (MIC) of ZnONPs was determined for the Candida albicans standard strain. The average size of ZnO conglomerates in the monomer solution of PMMA resin was measured using a dynamic light scattering instrument. PMMA resin samples with incorporated ZnONPs were produced. The morphology of nanopowder and the newly formed composite was examined under a scanning electron microscope (SEM). In addition, the roughness parameter of PMMA resin material was investigated before and after ZnONPs modification. RESULTS Nanopowder with the average particle size of 30 nm, density of 5.24 g/cm3 and surface area of 39 m2/g was obtained. MIC was determined at the level of 0.75 mg/mL. The average size of ZnO conglomerates in the monomer solution of acrylic resin dropped by 11 times after ultrasound activation. SEM examination of a newly formed composite showed a successful introduction of ZnONPs confirmed by the energy dispersive X-ray spectroscopy (EDS) analysis. There were no statistically significant differences in the biomaterial roughness before and after the modification of ZnONPs. CONCLUSION Zinc oxide nanoparticles were successfully incorporated into acrylic resin used for the production of denture bases. The presence of nanoparticles with sizes below 100 nm was confirmed. Nevertheless a newly created composite needs to be further investigated to improve its homogeneity, and to check its microbiological properties, strength and biocompatibility prior to its possible clinical use.

Assessment of temporomandibular joint disease.

The diagnosis of temporomandibular joint (TMJ) disorders consists of clinical (Reaserch Diagnostic Criteria for Temporomandibular Disorders, RDC/TMD) and additional (computer tomography, CT or magnetic resonance imaging, and MRI) examinations. Due to the growing knowledge of pathologic changes within the TMJ, the researches become more aware of the difficulty in detection the early symptoms of disorders using conventional examination. Therefore, it is now expected that the collected samples of synovial fluid, serum, or urine samples could enable easier identification of inflammatory process course, and degenerative cartilage changes state.

Occlusal Stabilization Splint Therapy in Orofacial Pain and Tension-Type Headache

Studies suggest an association between orofacial pain, accompanying temporomandibular disorders of myogenous origin, and headache, especially its tension-type. The occlusal appliance therapy is one of the options for the treatment of orofacial pain due to masticatory muscles tenderness. The aim of the present study was to assess the effectiveness of occlusal stabilization splint therapy in myofascial pain and tension-type headache in patients with sleep-disordered breathing. Forty three such patients were enrolled into the study group. The patients were treated with stabilization occlusal splint of vertical thickness at vertical jaw separation, established individually for each patient using a cephalometric analysis. The intensity of orofacial pain (numeric rating scale) and headache (analog rating scale), frequency of headache (%), and jaw qualitative function were assessed at baseline and after 2 and 6 months. Medians of headache and orofacial pain intensity were reduced after 6 months of treatment compared with baseline: 6.0 vs. 2.0 (p < 0.0001) and 6.0 vs. 1.0 (p < 0.0001), respectively. Pain decreased below 3 score points in 61.8 % of the patients with headache (p = 0.23) and in 85.3 % of patients with orofacial pain (p < 0.0001). Overall, the improvement in both signs and symptoms of orofacial pain was observed 81.4 % of patients after using occlusal stabilization splint for 6 months. We conclude that occlusal stabilization splint was effective in reducing painful symptoms of temporomandibular disorders of myogenous origin, a frequent feature of sleep disordered breathing.

Sleep-Related Breathing Disorders and Bruxism

Obstructive sleep apnea (OSA) syndrome is a sleep-related breathing disorder, due mainly to peripheral causes, characterized by repeated episodes of obstruction of the upper airways, associated with snoring and arousals. The sleep process fragmentation and oxygen desaturation events lead to the major health problems with numerous pathophysiological consequences. Micro-arousals occurring during sleep are considered to be the main causal factor for night jaw-closing muscles activation called bruxism. Bruxism is characterized by clenching and grinding of the teeth or by bracing or thrusting of the mandible. The causes of bruxism are multifactorial and are mostly of central origin. Among central factors there are secretion disorders of central nervous system neurotransmitters and basal ganglia disorders. Recently, sleep bruxism has started to be regarded as a physiological phenomenon occurring in some parts of the population. In this article we present an evaluation of the relationship between OSA and sleep bruxism. It has been reported that the frequency of apneic episodes and that of teeth clenching positively correlates in OSA. However, clinical findings suggest that further studies are needed to clarify sleep bruxism pathophysiology and to develop new approaches to tailor therapy for individual patients with concomitant sleep bruxism and OSA.

Implant supported dentures: an estimation of chewing efficiency

BACKGROUND Treatment of edentulous patients is one of the most demanding tasks the dentist can meet in his everyday practice. Implant based methods help to improve functioning of dentures and life quality of so treated patients. OBJECTIVES The aim of the study was to evaluate the chewing efficiency of patients treated with lower complete implant-supported overdentures and the simultaneous evaluation of treatment results by patients. MATERIALS AND METHODS For the investigation were chosen edentulous patients, treated with upper conventional complete dentures and lower complete overdentures supported on two implants. In this group of patients, were conducted investigations of chewing efficiency changes, based on the Optocal test and overdentures functioning evaluation made by patients in the survey. RESULTS The objective evaluation of the chewing efficiency indicated the decrease of this value in the five years of observations. Lower complete overdentures supported on implants significantly increased the comfort of chewing of edentulous patients. CONCLUSIONS The results of the study let us to assess positively the result of the therapy using titanium implants and lower complete overdentures. The therapy described significantly increases the life comfort of the edentulous patients. Decreasing chewing efficiency indicated by the research result should be compensated with the dentures maintaining or the prostheses exchange after about five years of use.

Mechanical and Physicochemical Properties of Newly Formed ZnO-PMMA Nanocomposites for Denture Bases

Aim: The aim of this study was to investigate the selected properties of zinc oxide- polymethyl methacrylate (ZnO-PMMA) nanocomposites that can influence the microorganism deposition on their surface. Materials and Methods: Non-commercial ZnO-NPs were prepared, characterized and used for the preparation of PMMA nanocomposite. Roughness, absorbability, contact angle and hardness of this new nanomaterial were evaluated. PMMA without ZnO-NPs served as control. Outcomes: Compared to unenriched PMMA, incorporation of ZnO-NPs to 7.5% for PMMA nanocomposite increases the hardness (by 5.92%) and the hydrophilicity. After modification of the material with zinc oxide nanoparticles the roughness parameter did not change. All tested materials showed absorption within the range of 1.82 to 2.03%, which meets the requirements of International Organization for Standardization (ISO) standards for denture base polymers. Conclusions: The results showed no significant deterioration in the properties of acrylic resin that could disqualify the nanocomposite for clinical use. Increased hydrophilicity and hardness with absorbability within the normal range can explain the reduced microorganism growth on the denture base, as has been proven in a previous study.

Comparative evaluation of custom and standard boil and bite (self-adapted) mouthguards and their effect on the functioning of the oral cavity

BACKGROUND Mouthguards provide an effective preventive method against the effects of injuries sustained during sports activities, in particular cycling, football, basketball, skiing or hockey. However, when placed in the oral cavity, they can induce disorders in basic physiological functions. AIM The objective of this clinical study was to compare the effects of various custom mouthguards with generally available standard boil and bite mouthguards on the functions of the oral cavity. MATERIAL AND METHODS A total of a 168 mouthguards (five custom and three standard boil and bite mouthguards) were assessed in a questionnaire-based survey. Their negative effects on the integrity of mucosa, speech, breathing, salivary flow and taste as well as in terms of inducing gag reflex, tooth clenching and temporomandibular joint complaints were compared. RESULTS Porida mouthguard was reported to have the most adverse effects on oral functions. In the majority of the respondents, the remaining mouthguards did not have any adverse effects on the stomatognathic system functions. CONCLUSIONS Mouthguards do not significantly disturb basic functions of the stomatognathic system. Standard Porida mouthguards were shown to have the most unfavourable effect on oral functions.