Microhardness of nanofilled composite resin light-cured by LED or QTH units with different times

Aim: To evaluate the influence of light-curing units and light-curing time on the microhardness of a nanofilled composite resin. Methods: Forty-five composite resin (Z350 - 3M) specimens were randomly prepared using Teflon ring molds (4.0 mm internal diameter and 2 mm depth) and divided into nine experimental groups (n=5): three polymerization units (conventional - 450 mW/ cm2; 2nd generation LED - 1100 mW/cm2; and 3rd generation LED - 700 mW/cm2) and three lightcuring times (20 s, 40 s, and 60 s). All specimens were polymerized with the light-curing tip positioned 8 mm far from the top surface of the specimen. After 24 h, Knoop microhardness measurements were made on the top and bottom surfaces of the specimen, with a load of 10 g for 10 s. Five indentations were made on each surface. All results were analyzed statistically by subdivided parcel ANOVA (Split-Plot) and Tukey's tests (p<0.05). Results: There were no statistically significant differences for the polymerization unit and light-curing time factors in either top or bottom surface. For all experimental conditions, the top surfaces showed greater hardness than the bottom surfaces (p<0.0001). Conclusions: The mode of polymerization and the lightcuring time did not affect the hardness of the nanofilled composite resin, and increasing the lightcuring time did not improve the hardness of the bottom surface of the composite resin.

Micromorphology and microhardness of enamel after treatment with home-use bleaching agents containing 10 percent carbamide peroxide and 7.5 percent hydrogen peroxide

OBJECTIVE: The purpose of this study was to assess the effect of home-use bleaching agents containing 10 percent carbamide peroxide and 7.5 percent hydrogen peroxide on enamel microhardness and surface micromorphology. MATERIAL AND METHODS: Enamel slabs (n=10) received the bleaching agents for 1 h/day and remained in artificial saliva solution for 23 h/day, during a total period of 21 days. Control group was composed of enamel slabs that were not subjected to treatment with the agents and were maintained in artificial saliva solution. Microhardness tests were performed before treatment application, 21 days of treatment and 14 days after the end of treatment. Scanning electron microscopy analyses were performed after 14 days after the end of bleaching treatment by 3 calibrated observers who attributed scores. RESULTS: The Tukey's test (á=0.05) showed no significant differences in microhardness values among bleaching agents, at 21 days of treatment and a significant increase in microhardness for different agents after 14 days from the end of treatment. Fisher's exact test showed differences in micromorphology of enamel between control and experimental groups (p=0.0342). CONCLUSIONS: Bleaching agents containing 10 percent carbamide peroxide and 7.5 percent hydrogen peroxide may change surface micromorphology of enamel, although no changes in microhardness were observed.

O uso de bifosfonatos e sua relação com a osteonecrose / The use of bisphosphonates and its relation to osteonecrosis

O uso dos bifosfonatos vem sendo amplamente indicado no tratamento da osteoporose, em alguns tipos de câncer e de metástases tumorais em tecidos ósseos. O bifosfonato inibe a formação de osteoclastos, interferindo no processo de reabsorção óssea, no entanto, o uso destas drogas vem sendo relacionado a casos de osteonecrose em maxila e mandíbula de pacientes que se submeteram a exodontia ou procedimentos cirúrgicos que tenham tido o tecido ósseo exposto ou manipulado. Procedimentos invasivos como exodontias ou cirurgias que manipulem o tecido ósseo devem ser submetidos a uma avaliação criteriosa em pacientes que estejam sob tratamento com bifosfonatos. Diante disso, este estudo tem como objetivo alertar o cirurgião-dentista em relação aos cuidados no manejo de pacientes que estejam sob tratamento com bifosfonatos, por meio de uma revisão na literatura e descrições de casos clínicos relatados.

The use of bisphosphonates has been widely used in the treatment of osteoporosis, in some cancer types and in metastases to bone. Bisphosphonates inhibit osteoclast formation, interfering in the process of bone reabsorption. However, the use of these drugs has been found to be related to osteonecrosis of maxillary and mandibular bones of patients which underwent to tooth extraction or surgical procedures with manipulation or exposure of bone tissue. Patients under treatment with bisphosphonates should be carefully assessed prior to undergoing invasive procedures such as tooth extraction or surgery that involves bone tissue. Therefore, the goal of this paper is to alert the dentist about the care of patients which are under treatment with bisphosphonates through a literature review that includes scientific papers and clinical cases.

Alterações bucais em pacientes com Síndrome de Sjõgren / Oral alterations in patients with Sjõgren's Syndrome

A Síndrome de Sjõgren (SS) é uma afecção auto-imune na qual o sistema imune compromete as glândulas exócrinas, envolvendo principalmente as glândulas salivares e lacrimais, determinando os quadros clínicos de xerostomia e ceratoconjuntivite seca. Entre os sintomas orais mais evidentes está a xerostomia, acarretando secura nos lábios, língua, faringe e conseqüente desconforto ao falar, mastigar e deglutir alimentos secos. A proposta deste trabalho foi apresentar um caso clínico de SS, enfatizando a sua importância clínica e a necessidade de um diagnóstico precoce, visando melhorar a qualidade de vida dos pacientes acometidos.

Verificação glicêmica casual de pacientes odontológicos / Casual glicemia of dental patients

O objetivo deste trabalho foi verificar o perfil glicêmico de pacientes odontológicos e propor um método para medir a glicemia destes indivíduos na consulta de rotina. Procurou-se também ressaltar a importância deste exame para o atendimento odontológico, prevenindo complicações. Após anamnese, 300 pacientes de ambos os gêneros, de 18 a 65 anos foram submetidos à medida rápida da glicemia capilar. Os voluntários eram pacientes de consulta odontológica de rotina em Campinas, SP e foram encaminhados ao serviço médico caso sua glicemia estivesse alterada. A glicemia mostrou-se alterada em 7% dos pacientes, dentre os quais apenas 2% sabiam ser portadores de diabete melito, porém julgavam estar com a glicemia controlada. Do total, 37% nunca haviam realizado teste glicemico. O método por análise imediata de glicemia durante atendimento odontológico pode ser empregado por ser útil como método de pré-diagnóstico de alterações metabólicas e como prevenção de complicações durante o atendimento odontológico.