Color and Luminescence stability of selected dental materials in vitro

To study luminescence, reflectance, and color stability of dental composites and ceramics. Materials and Methods: IPS e.max, IPS Classic, Gradia, and Sinfony materials were tested, both unpolished (as-cast) and polished specimens. Coffee, tea, red wine, and distilled water (control) were used as staining drinks. Disk-shaped specimens were soaked in the staining drinks for up to 5 days. Color was measured by a colorimeter. Fluorescence was recorded using a spectrofluorometer, in the front-face geometry. Time-resolved fluorescence spectra were recorded using a laser nanosecond spectrofluorometer. Results: The exposure of the examined dental materials to staining drinks caused changes in color of the composites and ceramics, with the polished specimens exhibiting significantly lower color changes as compared to unpolished specimens. Composites exhibited lower color stability as compared to ceramic materials. Water also caused perceptible color changes in most materials. The materials tested demonstrated significantly different initial luminescence intensities. Upon exposure to staining drinks, luminescence became weaker by up to 40%, dependent on the drink and the material. Time-resolved luminescence spectra exhibited some red shift of the emission band at longer times, with the lifetimes in the range of tens of nanoseconds. Conclusions: Unpolished specimens with a more developed surface have lower color stability. Specimens stored in water develop some changes in their visual appearance. The presently proposed methods are effective in evaluating the luminescence of dental materials. Luminescence needs to be tested in addition to color, as the two characteristics are uncorrelated. It is important to further improve the color and luminescence stability of dental materials.

Dental caries experience in Indians of the Upper Xingu, Brazil

The present study describes the experience of dental caries in Indians communities of the Xingu, in order to supply parameters for further analysis of trends of the disease in Indians. We performed oral health examination in 288 Indians from four communities (Yawalapiti, Aweti, Mehinaku and Kamaiura) living in the southern part of the Xingu National Park, using international criteria defined by the World Health Organization. The outcome measures were the DMFT and dmft scores, and the care index. Indians of the Upper Xingu presented high levels of caries, in all age groups. The average DMFT for 11 to 13-year-old children - 5.93 - was lower than the index measured in 1993 for 12-year-old schoolchildren in nearby cities - 8.23 -, whose United Nations' human development index ranked medium. However, Indians presented a much lower care index, per age group, than these cities, and a high ratio of missing teeth for persons above 20 years old. These observations indicate low incorporation of dental care services. The irregularity of the services programmed for these communities, and the changing dietary and cultural patterns, mainly derived from their contact with the non-indigenous population of Brazil, reinforce the pressing need for health promotion initiatives aimed at these groups.

In vitro SCREENING ANTIBACTERIAL ACTIVITY OF Bidens pilosa LINNÉ AND Annona crassiflora MART. AGAINST OXACILLIN RESISTANT Staphylococcus aureus (ORSA) FROM THE AERIAL ENVIRONMENT AT THE DENTAL CLINIC

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.

FACTORS RELATED TO ORAL CANDIDIASIS IN ELDERLY USERS AND NON-USERS OF REMOVABLE DENTAL PROSTHESES

This study examined the association between oral candidiasis in elderly users and nonusers of prosthesis and its predisposing factors. To this end, we performed a cross-sectional study where saliva samples from 48 patients were collected they used prosthesis and 43 patients (control group) who did not use. Among the 91 patients, Candida spp were isolated in 40 (83.3%) who used prosthesis and in 23 (53.5%) in the control group. A statistically significant association was determined between the two groups, the isolation of yeasts and dental prosthesis (p < 0.05, OR = 4.3). The most common etiological agent was Candida albicans (37 isolates), with 23 (62.2%) in the denture group and 14 (37.8%) (control group). Among patients who presented clinical manifestations of oral candidiasis (n = 24), 83.3% (n = 20) belonged to the group that wore dentures, while only 16.7% (n = 4) belonged to the control group. Elderly patients with diabetes had 4.4 times higher estimated risk of developing oral candidiasis when compared with individuals without this condition. There was no statistically significant association between being user prostheses and have diabetes with the onset of candidiasis. No statistically significant association was determined between xerostomia, use of prosthesis and oral candidiasis. The use of prosthetics and poor oral hygiene in elderly patients predisposes to the development of oral candidiasis.

Designing and implementing a performance: The case of Estomeo – Dental Industry

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics

Atividade antimicrobiana, antiaderente e antifúngica in vitro de plantas medicinais brasileiras sobre microrganismos do biofilme dental e cepas do gênero Candida

Avaliou-se in vitro a atividade antimicrobiana, antifúngica e antiaderente da aroeira-do-sertão, malva e goiabeira sobre microrganismos do biofilme dental e candidose oral. Os extratos mostraram-se eficazes, inibindo o crescimento das bactérias do biofilme dental e fungos da candidose oral, sugerindo a utilização dessas plantas como meio alternativo na terapêutica odontológica.

Dental and facial characteristics of patients with juvenile idiopathic arthritis

OBJECTIVE: It has been shown that the temporomandibular joint is frequently affected by juvenile idiopathic arthritis, and this degenerative disease, which may occur during facial growth, results in severe mandibular dysfunction. However, there are no studies that correlate oral health (tooth decay and gingival diseases) and temporomandibular joint dysfunction in patients with juvenile idiopathic arthritis. The aim of this study is to evaluate the oral and facial characteristics of the patients with juvenile idiopathic arthritis treated in a large teaching hospital. METHOD: Thirty-six patients with juvenile idiopathic arthritis (26 female and 10 male) underwent a systematic clinical evaluation of their dental, oral, and facial structures (DMFT index, plaque and gingival bleeding index, dental relationship, facial profile, and Helkimo's index). The control group was composed of 13 healthy children. RESULTS: The mean age of the patients with juvenile idiopathic arthritis was 10.8 years; convex facial profile was present in 12 juvenile idiopathic arthritis patients, and class II molar relation was present in 12 (P = .032). The indexes of plaque and gingival bleeding were significant in juvenile idiopathic arthritis patients with a higher number of superior limbs joints involved (P = .055). Anterior open bite (5) and temporomandibular joint noise (8) were present in the juvenile idiopathic arthritis group. Of the group in this sample, 94% (P = .017) had temporomandibular joint dysfunction, 80% had decreased mandibular opening (P = 0.0002), and mandibular mobility was severely impaired in 33% (P = .015). CONCLUSION: This study confirms that patients with juvenile idiopathic arthritis a) have a high incidence of mandibular dysfunction that can be attributed to the direct effect of the disease in the temporomandibular joint and b) have a higher incidence of gingival disease that can be considered a secondary effect of juvenile idiopathic arthritis on oral health.

Biofunctionalization of titanium surfaces for dental implants: osteogenic, anti-microbial and tribocorrosion resistant surfaces

PhD thesis in Biomedical Engineering

Color change using HSB color system of dental resin composites immersed in different common Amazon region beverages

The purpose of this study is to evaluate in vitro the color stability of composite resins when exposed to beverages with high coloring contents from the Amazon region. 240 samples from four different composite brands (Natural Look, Z350, 4Seasons and Opallis) of hue A3 were fabricated using an acrylic matrix. The samples were stored in distilled water at 37ºC for 24 hours. The initial color (T0) was registered using a Canon EOS Rebel XTi 10 mp camera, and then the samples were divided into four groups (n=15): G1 (coffee), G2 (açaí juice), G3 (energetic guaraná) and G4 (control - distilled water). The samples were exposed to solutions of DES (6hs) and RE (18hs) and placed in a double boiler under constant agitation, at 37ºC for 30 days. The samples were immersed in the coloring solutions for 15 minutes daily. After 7, 15 and 30 days, new photographic registers were made (T1, T2 and T3). The images were analyzed using Corel PHOTO-PAINT 12 software to identify the colors through the HSB system. The Kruskal-Wallis and t tests (p<0.05) demonstrated significant differences in color (hue, saturation and brightness). The results revealed that none of the tested composites showed color stability when exposed to coloring solutions, and that the Amazon region beverages (açaí juice and energetic guaraná) showed to be less coloring than coffee.

Comparative microscopic dental anatomy in the Petalodontida (Chondrichthyes, Elasmobranchii) / Rainer Zangerl --, H. Frank Winter --, Michael C. Hansen --.

n.s. no.26(1993)

Recruitment and retention incentives in health labour markets: an analysis of participation in NHS Scotland following Dental Vocational

This paper uses a unique individual level administrative data set to analyse the participation of health professionals in the NHS after training. The data set contains information on over 1,000 dentists who received Dental Vocational Training in Scotland between 1995 and 2006. Using a dynamic nonlinear panel data model, we estimate the determinants of post-training participation. We nd there is signi cant persistence in these data and are able to show that the persistence arises from state dependence and individual heterogeneity. This finding has implications for the structure of policies designed to increase participation rates. We apply this empirical framework to assess the accuracy of predictions for workforce forecasting, and to provide a preliminary estimate of the impact of one of the recruitment and retention policies available to dentists in Scotland.

Paleopatología dental de una muestra esquelética del área funeraria del suburbio oriental de Tarraco (siglo I-III d. C.)

Los dientes son una importante fuente de información en el estudio de poblaciones del pasado. El estudio de las enfermedades dentales en restos esqueléticos antiguos busca reconstruir la forma de vida de las poblaciones antiguas relacionadas con su estado de salud y enfermedad.