Description of a Rat Palatal Acrylic Plate That Can Be Relined.

PURPOSE: The objective of this article is to describe a method to construct an intraoral acrylic device that permits a reline material to be added to the inner surface of the palatal plate. MATERIALS AND METHODS: Fifteen 60-day-old adult female rats (Rattus Norvegicus Albinus Wistar), weighing 150 to 250 g were used for this study and allocated to three groups (n = 5): G1, animals wearing a heat-polymerized acrylic resin palatal plate (Lucitone 550) for 14 days; G2, animals wearing a heat-polymerized acrylic resin palatal plate (Lucitone 550) relined with Tokuyama Rebase II for 14 days; and G3, animals maintained under the same conditions as the experimental groups, without wearing palatal plates for 14 days. The manipulation of the animals followed the guidelines of the Brazilian College of Animal Experimentation, under the approval of the animal ethics committee of the State University of Ponta Grossa. The palatal plates covered the whole palate, were fixed in the molar region with light-cured resin, and were kept there for 14 days. The animals received a paste diet and water ad libitum. Before and after the trial period, the rats were weighed individually on a precision scale. Statistical analysis was performed using a two-way analysis of variance (α = 0.05) test for comparison of the animals' weight (g) at time 0 and after 14 days of using the palatal plate. RESULTS: No statistical differences were observed regarding the weight of the animals among the experimental groups in the study. CONCLUSIONS: The individual master impressions, the molar teeth coverage, and the method of cementation with nonadhesive composite resin provided good stability for the palatal plate showed in this study, not disturbing the eating habits and nutrition of the animals. This model seems reproducible, offering adequate histopathological evaluation. Differences in tissue morphology exist between the animals that used the palatal plate and the animals that did not use this device. Use of these palatal plates could clarify how prostheses bring changes in the palatal mucosa of users.

Histopathological changes by the use of soft reline materials: a rat model study.

AIM: To assess the histopathological changes of rat palatal mucosa exposed to soft reline materials. METHODS: Forty-five adult female Wistar rats with controlled living conditions and fed ad libitum were employed. Palatal appliances of heat-polymerized acrylic resin Lucitone 550 were manufactured and worn by forty animals during 14 days. Five animals did not use the appliances (G1) and were used to control the appliance influence. One experimental group (n = 10) used the appliances without any relining material (G2) to control the material effect. Three experimental groups (n = 10) received the following soft reline materials below appliances: Dentusoft (G3), Dentuflex (G4), and Trusoft (G5). Appliances from half of each experimental group(n = 5) was immersed in water bath at 55°C for 10 min before use. Animals were slaughtered and the palates were fixed in 10% buffered formalin. Hematoxylin and eosin stained sections of 5 µm were analyzed by computerized planimetry. Cellular compartment, keratin and total epithelial thickness, and basement membrane length were measured to histopathological description.Analysis of variance and Tukey post-hoc test were used to data examination(α = 0.05). RESULTS: For heat-treatment groups, G4 showed less elongated ridges at the basal layer interface (p = 0.037) than G2. When comparing the conditions with and without heat-treatment, only G2 showed a significant decrease in the cellular compartment, keratin layer and total epithelium thickness (p<0.05). CONCLUSION: The post-polymerization for Lucitone 550 was an effective method to reduce the changes in the rat palatal mucosa. The soft reline materials tested did not cause significant histopathological changes in the rat palatal mucosa.

Avaliação clínica do uso de um dessensibilizante antes do clareamento de consultório / Clinical evaluation of a desensitizing agent used before in-office bleeching

Objetivo: avaliar clinicamente o efeito de um agente dessensibilizante utilizado previamente. ià aplicação de um gel de peróxido de hidrogênio 3S% (PH3S) na eficiência do clareamento (EC) ."e sensibilidade dental (50). Material e Métodos: Foram selecionados 30 pacientes divididos em grupo placebo (GP; n=lS) e grupo experimental (GE; n=lS). Um gel placebo ou dessensibilizante (Oesensibilize KF 2%) foi aplicado sobre as superfícies vestibulares dos dentes durante 10 minantes do clareamento com PH3S (Whiteness HP Blue 3S%). Este protocolo foi repetido na l' . e 2' sessões. Os pacientes utilizaram uma escala de O a 4 para anotarem a sensibilidade. A corfoi registrada no início e após a l' e 2' sessões de clareamento usando a escala Vita ordenada por valor. A EC foi analisada estatisticamente pelos testes de análise de variância e de Tukey. A porcentagem de pacientes com 50, assim como a intensidade foram avaliados pelos testes exato de Fisher e Mann-Whitney (a=O,OS), respectivamente. Resultados: O uso de um agente dessensibilizante não afetou a EC (cor B1/A 1 após duas semanas para 90% dos pacientes). 40% e 6,7% dos participantes do GP e GE, respectivamente apresentaram 50 (p < O,OS). A intensidade da 50 foi similar para os grupos (p > O,OS). Conclusão: O uso de um agente dessensibilizante antes do clareamento de consultório reduziu a prevalência de 50.

Objective: To evaluate the bleaching efficiency (BE) and tooth sensitivity (T5) of a desen¬sitizing agent used before in-office bleaching with 3S% hydrogen peroxide gel. Methods: We selected 30 patients for this study, which were divided into placebo and experimental groups. A placebo or desensitizing gel (Oesensibilize KF 2%) was applied on the buccal surfaces of ali teeth for 10 min (n = lS). This protocol was repeated one week later. Patients used a scale of O to 4 to write down their tooth sensitivity. The color was registered before and after the 1 st and 2nd sessions of bleaching using a value-oriented Vita Classical scale. The BE was analyzed by ANOVA and Tukey tests. The % of patients with T5 as well as T5 intensity was analyzed by the Fisher's exact and Mann-Whitney tests (a=O.OS). Results: The use of a desensitizing gel didn 't affect the BE (B 1 /A 1 color after two weeks for 90% of patients). 40% and 6.7% of the participants from the placebo and experimental groups presented T5 (pO.OS). Conclusion: The use of desensitizing gel before in-office bleaching reduced the prevalence of this side effect.

Presença de candida spp em sulco periimplantar e saliva de pacientes desdentados totais e parciais reabilitados com implantes osseointegrados / Presence of candida in periimplantar sulcus and saliva of partially or totally edentulous patientes with osseointegrates implants

A falha de implantes pode ser produzida por trauma oclusal ou infecções periimplantares, chamadas periimplantites, que podem ser causadas por bactérias Gram negativas, bacilos entéricos, Staphylococcus aureus ou Candida. Neste estudo foi comparada a prevalência de Candida spp no sulco periimplantar e saliva de 14 pacientes desdentados parciais, oito desdentados totais, reabilitados há mais de 6 meses com implantes osseointegrados de titânio; de ambos os gêneros, entre 42 e 78 anos. As amostras foram coletadas na região dos pré-molares inferiores, sem doença periodontal clínica e sem reabsorção óssea radiográfica, introduzindo-se três cones de papel esterilizados no sulco periimplantar por 1 min. A seguir, os cones foram transferidos para tubos contendo 3 ml caldo Sabouraud Dextrose; as amostras foram homogeneizadas e diluídas até 10-3. Alíquotas de 0,1 mL foram semeadas em duplicata, em ágar Sabouraud dextrose com cloranfenicol e incubadas a 37°C/48h e cinco dias em temperatura ambiente, quando determinou-se o número de ufc/mL de Candida. Amostras de saliva foram obtidas dos mesmos pacientes, com auxílio de um swab que foi passado por toda a cavidade bucal e processado de modo semelhante ao descrito para as amostras do sulco periimplantar. Não houve diferença significante no número de Candida spp entre desdentados parciais e totais (sulco p=0,6197; saliva p= 0,7283), mostrando que a presença de dentes naturais não interferiu na colonização da cavidade bucal pelo fungo.