Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

This in vitro study evaluated the cytotoxicity of an experimental restorative composite resin subjected to different light-curing regimens. METHODS: Forty round-shaped specimens were prepared and randomly assigned to four experimental groups (n=10), as follows: in Group 1, no light-curing; in Groups 2, 3 and 4, the composite resin specimens were light-cured for 20, 40 or 60 s, respectively. In Group 5, filter paper discs soaked in 5 µL PBS were used as negative controls. The resin specimens and paper discs were placed in wells of 24-well plates in which the odontoblast-like cells MDPC-23 (30,000 cells/cm²) were plated and incubated in a humidified incubator with 5% CO2 and 95% air at 37ºC for 72 h. The cytotoxicity was evaluated by the cell metabolism (MTT assay) and cell morphology (SEM). The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: In G1, cell metabolism decreased by 86.2%, indicating a severe cytotoxicity of the non-light-cured composite resin. On the other hand, cell metabolism decreased by only 13.3% and 13.5% in G2 and G3, respectively. No cytotoxic effects were observed in G4 and G5. In G1, only a few round-shaped cells with short processes on their cytoplasmic membrane were observed. In the other experimental groups as well as in control group, a number of spindle-shaped cells with long cytoplasmic processes were found. CONCLUSION: Regardless of the photoactivation time used in the present investigation, the experimental composite resin presented mild to no toxic effects to the odontoblast-like MDPC-23 cells. However, intense cytotoxic effects occurred when no light-curing was performed.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Toxicity of chlorhexidine on odontoblast-like cells

Chlorhexidine gluconate (CHX) is recommended for a number of clinical procedures and it has been pointed out as a potential cavity cleanser to be applied before adhesive restoration of dental cavities. OBJECTIVE: As CHX may diffuse through the dentinal tubules to reach a monolayer of odontoblasts that underlies the dentin substrate, this study evaluated the cytotoxic effects of different concentrations of CHX on cultured odontoblast-like cells (MDPC-23). MATERIAL AND METHODS: Cells were cultured and exposed to CHX solutions at concentrations of 0.06%, 0.12%, 0.2%, 1% and 2%. Pure culture medium (&#945;-MEM) and 3% hydrogen peroxide were used as negative and positive control, respectively. After exposing the cultured cells to the controls and CHX solutions for 60 s, 2 h or 60 s with a 24-h recovery period, cell metabolism (MTT assay) and total protein concentration were evaluated. Cell morphology was assessed under scanning electron microscopy. CHX had a dose-dependent toxic effect on the MDPC-23 cells. RESULTS: Statistically significant difference was observed when the cells were exposed to CHX in all periods (

Toxicity of chlorhexidine on odontoblast-like cells

Chlorhexidine gluconate (CHX) is recommended for a number of clinical procedures and it has been pointed out as a potential cavity cleanser to be applied before adhesive restoration of dental cavities. OBJECTIVE: As CHX may diffuse through the dentinal tubules to reach a monolayer of odontoblasts that underlies the dentin substrate, this study evaluated the cytotoxic effects of different concentrations of CHX on cultured odontoblast-like cells (MDPC-23). MATERIAL AND METHODS: Cells were cultured and exposed to CHX solutions at concentrations of 0.06%, 0.12%, 0.2%, 1% and 2%. Pure culture medium (&#945;-MEM) and 3% hydrogen peroxide were used as negative and positive control, respectively. After exposing the cultured cells to the controls and CHX solutions for 60 s, 2 h or 60 s with a 24-h recovery period, cell metabolism (MTT assay) and total protein concentration were evaluated. Cell morphology was assessed under scanning electron microscopy. CHX had a dose-dependent toxic effect on the MDPC-23 cells. RESULTS: Statistically significant difference was observed when the cells were exposed to CHX in all periods (p<0.05). Significant difference was also determined for all CHX concentrations (p<0.05). The 60-s exposure time was the least cytotoxic (p<0.05), while exposure to CHX for 60 s with a 24-h recovery period was the most toxic to the cells (p<0.05). CONCLUSION: Regardless of the exposure time, all CHX concentrations had a high direct cytotoxic effect to cultured MDPC-23 cells

Importância da abordagem precoce no tratamento odontológico de pacientes portadores de necessidades especiais.

Introduction: the patients with specials necessities ne ed a singular dentistry treatment because they have limitations due to theirs deficiency. The quality of oral health is related to the clinical situation of patient. The individuals with motor and understanding problems have poor oral health. Aim: this st udy aimed to review the literature about the importance of the early dentistry treatment of pacients with specials necessities. Methodology: the review of literature was made through t he Pubmed and Bireme. Studies about dental caries and periodontal dise a se of patient s with specials necessities had shown high index of caries and periodontal disease. Therefore it is important that there are capacity p rofessionals and multidisciplinary treatment. It is necessary to supply the dificulties of treatment like an xiety of parents, systemic problems and discrimination. Conclusion: the early treatment results in good coperation during the treatment, and the aquisition of cares for all life. The best way is a program of oral health with instructions about diet, oral hygiene, control of bacterials, motivation and interaction between patients and professionals.Introdução: os pacientes portadores de necessidades especiais re querem um tratamento odontológico diferenciado devido às limitações determinadas por sua deficiência. A qualidade da higiene bucal está relacionada ao quadro clínico do paciente, tendo os indivíduos com problemas de motricidade e inteligência, a higiene bu cal comprometida. Objetivo: realizar uma revisão da literatura a respeito da importância da abordagem precoce no tratamento odontológico de pacientes com necessidades especiais. Metodologia: a revisão de literatura foi realizada por meio de levantamento bibliográfico no Pubmed e Bireme. Estudos epidemiológicos da condição de cárie e doenças gengivais de pacientes com necessidades especiais demonstram índice de cárie e problemas periodontais elevados. Desse modo, é importante que haja profissionais capacit ados e abordagem multidisciplinar adequada, para suprir as barreiras impostas durante o seu atendimento, como a ansiedade dos pais, problemas sistêmicos, discriminação, entre outras. Conclusão: a busca por auxílio, o mais cedo possível, resulta em maior c ooperação frente ao tratamento odontológico, e na aquisição de cuidados que se perpetuam por toda a vida do paciente. Um programa de promoção de saúde bucal voltado especificamente a esses pacientes, envolvendo orientações de higiene bucal, dieta, controle de placa, motivação e interação dos pacientes com o profissional, a família e a sociedade, mostra - se como o melhor caminho

Restoration of severely decayed primary incisors using indirect composite resin restoration technique

Caries of primary incisors is a common problem in paediatric dentistry in some countries. The restoration of primary incisors which have been severely damaged by early childhood caries or trauma is also a difficult challenge for clinicians. This case report describes an indirect technique for the restoration of primary anterior teeth using composite resin reinforced with a fibreglass post. Over a one-year period, the crowns have demonstrated good retention and aesthetic results. The restorations were provided in two short chair-side sections, with satisfactory patient cooperation. © 2005 BSPD and IAPD

Evaluation of 2 endodontic techniques used to treat human primary molars with furcation radiolucency area: A 48-month radiographic study

Objective: To evaluate 2 techniques for the treatment of human primary molars with necrotic Pulp and bifurcation bone loss by means of radiographic examination for 48 months. Method and Materials: Fifty-one mandibular primary molars were evaluated in children ranging from 4.5 to 6.5 years of age. The teeth with necrotic pulp and bifurcation bone loss were diagnosed by radiographic examination. The teeth were divided into 2 groups: group 1 (28 teeth)-pulpotomy technique using formocresol as a temporary dressing between sessions and coronal chamber obturation with zinc oxide-eugenol cement; and group 2 (23 teeth)-pulpectomy technique with calcium hydroxide paste as a temporary dressing between sessions and root canal obturation with a dense Calcium hydroxide paste. Standardized radiographs were taken immediately after the fillings were completed and after 12, 24, 36, and 48 months. The radiographs were digitized and analyzed with software that outlined and measured the bifurcation radiolucency. Results: Bifurcation radiolucency reduced significantly or repaired completely for both treatnients in the first 12 months. Minor radiographic reduction of the lesion was observed from 12 to 24 months, and no significant reduction of the remaining radioulcent area was observed from 24 to 48 months after treatment. Conclusion: The 2 endodontic techniques evaluated showed similar results. The main effect of treatment on the lesion repair was obtained in the first year after treatment

Adaptações do ambiente odontológico para o atendimento do paciente com necessidades especiais.

Adaptações do ambiente odontológico para o atendimento do paciente com necessidades especiais