Validation of the Geriatric Oral Health Assessment Index in complete denture wearers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of post-polymerization heat treatment on a denture base acrylic resin: histopathological analysis in rats

This work examined the histological effects, on the rat palatal mucosa, of a denture base acrylic resin, submitted or not to a post-polymerization heat-treatment. Methods: Fifteen adult female Wistar rats, with sixty days old, weighting 150 g – 250 g were divided in G1: animals being maintained under the same conditions as the experimental groups following described, but without the use acrylic palatal plates (control group); G2: use of heat-polymerized acrylic resin palatal plates made of Lucitone 550; G3: use of palatal plates identical to G2, but subjected to a post-polymerization treatment in a water bath at 55°C for 60 min. The plates covered all the palate and were fixed in the molar region with light-cured resin, thus being kept there for 14 days. After the sacrifice, the palate was removed, fixed in formaldehyde 10% and decalcified with EDTA. Sections were stained using haematoxylin and eosin. Images in duplicate were made from the central region of the cuts, to measure the thickness (μm) of the keratin layers (TKC), epithelium total (TET) and connective tissue (TCC). Statistical analyses were carried out by one-way ANOVA and Tukey post-tests (α=0.05). Results: According to the results there was significant difference in the thickness of keratin between G2 and G3, with G1 having the intermediate value and similar to the other groups. There was a significant difference in the connective tissue with G3 denture base investigated.

Colour stability of acrylic resin denture teeth after immersion in different beverages

The colour stability of acrylic resin denture teeth in beverages was investigated. A spectrophotometer measured the colour (CIE-L*a*b* system) of all specimens after storage in distilled water for 24 h at 37°C (T0). Specimens were then immersed in various beverages. After 15 days (T1) and 30 days (T2), for each material, the mean ∆E values were calculated and compared by two-way ANOVA and Tukey intervals (α=0.05). In the ∆T0T1 period, specimens stored in red wine were significantly discoloured, compared to distilled water (P=0.003). There was no difference between immersion solutions in ∆ET0T2 (P=0.772) and in ∆ET1T2 (P=0.058), and no difference between materials in all immersion periods.

Effect of a Denture Adhesive on the Satisfaction and Kinesiographic Parameters of Complete Denture Wearers: A Cross-Over Randomized Clinical Trial

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo de nanocompósitos luminescentes baseados em complexos de Eu(III) e Ir(III) ancorados à nanopartículas de sílica por bases de Schiff

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Reflexões sobre a variação terminológica na lexicografia corrente no Brasil e a construção das bases teórico-metodológicas para o dicionário de lexicografia brasileira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Estudo de propriedades da resina acrílica termoativada por energia de micro-ondas frente às variações nos procedimentos de inclusão

On heat cured acrylic resins by microwaves energy the action of electromagnetic waves on methylmethacrylate promote the polymerization process. However, part of this energy is absorbed by the gypsum present in the flask and the function of this gypsum is to maintain the characteristics of specimen, nevertheless is unknown in the literature as the amount of water present in this gypsum affects the characteristics of acrylic resin. The proposal of this study was verified if dried gypsum influenced in some properties of the acrylic resins thermally activated by microwaves: presence of porosity, microhardness, roughness, flexural strength and dimensional change. Two different types of acrylic resin for complete denture were utilized: Lucitone 550 e Vipi-Wave and groups were formed: Lucitone 550, polymerization by microwave energy without gypsum treatment; Lucitone 550, polymerization by microwave energy with pretreatment gypsum; Vipi-Wave by microwave energy without gypsum treatment; Vipi Wave, polymerization by microwave energy with pretreatment gypsum; Lucitone 550 control group polymerization in hot water bath. For both situations were performed analysis of microhardness and porosity three different metallic shaped specimens were formed with followed dimensions: 2,0x2,0x2,0cm (8cm3); 2,0x2,0x1,0 (4cm3) e 2,0x2,0x0,5 (2cm3). Standardized wax specimens was used to prepare groups (n=9) and included in glass fiber flasks. The gypsum dry was made by microwave oven cycle (10min and 600W) and then the flasks were maintained in dry oven during two hours. Polymerizations of specimens were made and then polished. Wax patterns #7 obtained from the metal were embedded in plastic flask and following the processes of pressing and polymerization of the resin according to established groups. To evaluate the flexural strength, specimens 65mm x 10mm x 3.0mm from metallic patterns in bar format were made. ...

Quality of life and satisfaction of patients wearing implant-supported fixed partial denture: a cross-sectional survey of patients from Aracatuba city, Brazil

ObjectivesThe aim of this study was to evaluate the quality of life and satisfaction of patients wearing implant-supported fixed partial dentures.Materials &methodsA total of 106 patients were selected and submitted to clinical examination and collection of the demographic data for evaluation of the implant-supported fixed dentures conditions. All participants agreed to answer to the Oral Health Impact Profile (OHIP-EDENT) questionnaire and another questionnaire about satisfaction with the implant-supported prostheses. The patients were classified into the following three groups for statistical analysis: patients wearing splinted implant-supported prosthesis (E), patients wearing single implant-supported prosthesis (U), and patients wearing single implant-supported prosthesis associated with splinted prosthesis (E+U). Kruskal-Wallis test was used to compare the answers between the groups, and a logistic regression model was measured to verify the relation between variables of the patients and the questionaries'items.ResultsThere were significant differences among groups (P=0.006) for discomfort during surgery itself of the satisfaction questionnaire. The marital status, groups, and hygiene condition were significant mainly for physical pain item.ConclusionsIt was concluded that the patients presented high level of satisfaction and quality of life for the most of the items evaluated as well as the groups showed similar results.

Long-term clinical evaluation of the color stability and stainability of acrylic resin denture teeth

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of short-term immersion and brushing with different denture cleansers on the roughness, hardness, and color of two types of acrylic resin

Purpose: To investigate the cumulative effects of brushing (B) or immersion (I), using different cleansing agents, on the surface roughness, hardness and color stability of a heat-polymerized denture resin, Lucitone 550 (L), and a hard chairside reline resin, Tokuyama Rebase Fast II (T). Methods: A total of 316 specimens (10 x 2 mm) were fabricated. The specimens (n= 9) were divided into brushing or immersion groups according to the following agents: dentifrice/distilled water (D), 1% sodium hypochlorite (Na0C1), Corega Tabs (Pb), 1% chlorhexidine gluconate (Chx), and 0.2% peracetic acid (Ac). Brushing and immersion were tested independently. Assays were performed after 1, 3, 21, 45 and 90 blushing cycles or immersion of 10 seconds each. Data were evaluated statistically by repeated measures ANOVA. Tukey's honestly significant difference (HSD) post-hoc test was used to determine differences between means (a= 0.05). Results: For L there was no statistically significant difference in roughness, except a significant decrease in roughness by brushing with D. T showed a significant effect on the roughness after 90 immersions with Ac. Hardness values decreased for L when specimens were immersed or brushed in Na0C1 and Pb. The hardness of T decreased with increases in the repetitions (immersion or brushing), regardless of the cleaning method. Values of color stability for L resin showed significant color change after brushing with and immersion in Ac and Pb. Brushing with D exhibited a higher incidence of color change. For T there were no significant differences between cleaning agents and repetitions in immersion. A color change was noted after three brushings with the Ac, Chx, and D. Brushing with dentifrice decreased roughness of L. Immersion in or brushing with Na0C1 and Pb decreased the hardness of L. For T, hardness decreased with increases in immersions or brushing. Color changes after the immersion in or brushing with cleaning agents were clinically acceptable according to National Bureau of Standards parameters for both resins.

Masticatory performance of complete denture wearers after using two adhesives: a crossover randomized clinical trial

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of polymerization methods and thermal cycling on color stability of acrylic resin denture teeth

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Denture stomatitis--presence of bacteria and yeasts

The presence of yeasts and bacteria was studied in 26 patients with denture stomatites, and the results compared with the data of the normal mucosa foi edentoulous patients, who used or not upper dentures. The use of dentures caused an increase in the amount of yeasts, and there was a correlation with the severity of the stomatitis. Gram positives cocci and bacilus predominated in all studied groups, but in cases of stomatitis there was an increase in the amount of Gram negative cocci and filamentous. These results suggest that besides yeasts, modifications of the bacteria flora can be relevant for the development of denture stomatitis.

Acrylic resin cytotoxicity for denture base - Literature review

Acrylic resin is a widely used material in clinical practice, and a satisfactory biocompatibility is essential. When the resin polymerization reaction is incomplete, residual monomers are released into the oral cavity. The aim of this study was to evaluate, through a literature review, the cytotoxicity caused by the denture base acrylic resin used, and its components. The selection of published studies was performed on the Pubmed database from January 2008 to July 2013. The keywords used were: cytotoxicity and acrylic resins, cytotoxicity and denture base resins and cytotoxicity and oral prosthesis. Inclusion criteria were: in vitro studies and literature reviews published in English that evaluated the acrylic resin cytotoxicity for denture base and its components. Studies with no reference to the search strategy were excluded. A total of 182 articles were found. Among these, only 13 were included for writing this review. The MTT test is the most common test used to evaluate acrylic resin cytotoxicity. Auto-polymerized resin is more cytotoxic than heat-polymerized resin because of its higher quantity of residual monomers which cause cell and tissue changes in the oral mucosa. However, more studies are necessary for the development of biocompatible materials.

Prosthetic rehabilitation of a patient after a partial mandibulectomy

The treatment of orofacial tumors may cause facial deformities by losses of structures that affect basic functions, i.e. feeding, speech, and the reduction of patient self-steam. A white male patient was diagnosed with epidermoid cancer on the mandibular alveolar ridge with infiltration staging IV A. The patient was submitted to a mandibulectomy associated with a complete extraction of mandibular teeth. For rehabilitation, a conventional denture for the mandibular arch and a removable partial denture for the maxillary arch were fabricated. A correct occlusal adjustment and a satisfactory amount of alveolar bone was favorable for conventional dentures of the prostheses bases improve their retention and stability. After one year of follow-up, the patient was adapted to the prostheses, satisfied with their retention, and reported an improvement on his feeding. The prosthetic rehabilitation of patients after a partial mandibulectomy is essential for their self-steam. Conventional dentures may have their retention and stability improved if they are well fabricated, recorded and have a balanced occlusion. A correct occlusal adjustment and an adequate retention of the prostheses bases may improve their retention and stability. Patients without xerostomy and with a satisfactory amount of alveolar bone may have a favorable prognosis for conventional dentures.