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 percent, 0.12 percent, 0.2 percent, 1 percent and 2 percent. Pure culture medium (á-MEM) and 3 percent 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.

Cytotoxicity evaluation of Persica mouthwash on cultured human and mouse cell lines in the presence and absence of fetal calf serum.

Background and Aims: The effectiveness of an ideal antimicrobial agent depends on its ability to kill microbes while causing minimal toxicity to host cells. Several studies have been reported on the antimicrobial effects of chewing sticks (Salvadora persica) on oral bacteria. The purpose of this study was to evaluate the cytotoxic effects of Persica™ and chlorhexidine (CHX) mouthwashes on cultured human and mouse cell lines. Materials and Methods: This was an experimental study. The toxic effects of four dilutions of Persica™ and CHX mouthwashes on KB, Saos-2, J744 A1, and gingival fibroblast cells were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay. The effect of fetal calf serum (FCS) components on the cytotoxicity of these mouthwashes was also investigated. Statistical Analysis: Analysis of variance and the Kruskal-Wallis test were used to evaluate the results. Results: The results indicated that Persica™, at concentrations higher than 0.1%, exerted a very significant cytotoxic effect on all the cell lines (P < 0.01). CHX, at a concentration of 0.001%, exerted toxic effects only on gingival fibroblasts; concentrations higher than 0.001% were required to produce significant cell death in the other cell lines. At all the concentrations under study, both Persica™ and CHX exerted significantly greater cytotoxic effects in the absence of FCS than in its presence (i.e., in control culture medium). The toxicities of both mouthwashes were attenuated in the presence of FCS (10%). Conclusion: Our results indicate that both Persica™ and CHX mouthwashes are toxic to macrophage, epithelial, fibroblast, and osteoblast cells in a concentration-dependent manner.

Subcutaneous tissue response of isogenic mice to calcium hydroxide-based pastes with chlorhexidine

This study was evaluated the response of subcutaneous connective tissue of isogenic mice to calcium hydroxide-based pastes with chlorhexidine digluconate (CHX). Seventy isogenic male BALB/c mice aged 6-8 weeks and weighing 15-20 g were randomly assigned to 8 groups. The animals received polyethylene tube implants as follows: Groups I, II, and III (n=10) - Calen® paste mixed with 0.4 percent CHX (experimental paste; Calen/CHX) for 7, 21, and 63 days, respectively; Groups IV, V, and VI (n=10) - UltraCal™ paste mixed with 2 percent CHX (experimental paste supplied by Ultradent Products Inc.; Ultracal/CHX) for 7, 21, and 63 days, respectively; and Groups VII and VIII (n=5): empty tube for 7 and 21 days, respectively. At the end of the experimental periods, the implants were removed together with the surrounding tissues (skin and subcutaneous connective tissue). The biopsied tissues were subjected to routine processing for histological analysis. Using a descriptive analysis and a four-point (0-3) scoring system, the following criteria were considered for qualitative and quantitative analysis of the tissue around the implanted materials: collagen fiber formation, tissue thickness and inflammatory infiltrate. A quantitative analysis was performed by measuring the thickness (µm), area (µm²) and perimeter (µm) of the reactionary granulomatous tissue formed at the tube ends. Data were analyzed statistically by the Kruskal-Wallis test and Dunn's post-test (á=0.05). Calen/CHX showed biocompatibility with the subcutaneous and reactionary tissues, with areas of discrete fibrosis and normal conjunctive fibrous tissue, though without statistically significant difference (p>0.05) from the control groups. In Groups I to III, there was a predominance of score 1, while in Groups IV to VI scores 2 and 3 predominated for all analyzed parameters. UltraCal/CHX, on the other hand, induced the formation of an inflammatory infiltrate and abundant exudate, ...

O objetivo do presente estudo foi avaliar a resposta do tecido conjuntivo subcutâneo de camundongos isogênicos frente a pastas à base de hidróxido de cálcio, associadas ao digluconato de clorexidina (CHX). Setenta camundongos isogênicos BALB/c machos, com 6-8 semanas e pesando 15-20 g foram aleatoriamente divididos em 8 grupos. Os animais receberam implantes de tubos de polietileno contendo: Grupos I, II e III (n=10) - pasta Calen® associada à CHX a 0,4 por cento (Calen/CHX), por 7, 21 e 63 dias, respectivamente; Grupos IV, V e VI (n=10) - pasta UltraCal™ associada à CHX a 2 por cento (pasta experimental fornecida pela Ultradent Products Inc.; Ultracal/CHX), por 7, 21 e 63 dias, respectivamente; e Grupos VII e VIII (n=5) - tubo de polietileno vazio, por 7 e 21 dias, respectivamente. Decorridos os períodos experimentais, os implantes foram removidos juntamente com os tecidos circundantes (pele e tecido conjuntivo). Os tecidos foram submetidos ao processamento histotécnico de rotina, para análise histopatológica. Empregando um sistema de escores, os seguintes critérios foram considerados para a análise qualitativa e quantitativa: fibrosamento, espessura tecidual e infiltrado inflamatório. Foi efetuada, também, a análise quantitativa da medida da espessura (µm), área (µm²) e perímetro (µm) do tecido granulomatoso reacional formado na abertura dos tubos. Os dados obtidos foram submetidos à análise estatística, empregando o teste de Kruskal-Wallis e o pós-teste de Dunn. O nível de significância adotado foi de 5 por cento. Os resultados demonstraram biocompatibilidade da pasta Calen associada à CHX a 0,4 por cento com o tecido adjacente, com fibrosamento discreto, assim como tecido conjuntivo normal, sem diferença estatística significante com os controles (p>0,05). Nos Grupos I, II e III houve predominância do escore 1, enquanto que nos Grupos IV, V e VI houve predominância dos escores 2 e 3, em todos os parâmetros analisados. Em relação ...

Effect of three commercial mouth rinses on cultured human gingival fibroblast: an in vitro study.

AIM: To examine the effect of three commercial mouth rinses (Hexidine 0.2%, Listerine Cool Mint, Betadine 1%) upon cultured human gingival fibroblast proliferation. MATERIALS AND METHODS: Human gingival fibroblasts were cultured and incubated in Dulbecco's Minimum Eagle's Medium containing Chlorhexidine, Listerine, Povidone-Iodine at varying concentrations (1%, 2%, 5%, 10%, 20% and 100% of the given solution) at 37 degrees C for 1, 5 and 15 min. Control cells received an equal volume of Dulbecco's Minimum Eagle's Medium without adding mouth rinses, for similar duration of exposure at 37 degrees C. Following incubation the media were removed, cells were washed twice with medium, supplemented with 10% Fetal Bovine Serum, and fibroblasts in the test and control group were allowed to recover in the same media for 24 h. RESULTS: In all the three groups, the proliferation inhibition was dependent on the concentration of solublized mouth rinses in the cell culture but independent of the duration of exposure to all three mouth rinses. The results showed that all three solutions were toxic to cultured human gingival fibroblasts, Chlorhexidine being the most cytotoxic. It was seen that at dilute concentrations (1% and 2% of given solutions) Listerine was more cytotoxic than Chlorhexidine and Povidone-Iodine. CONCLUSION: These results suggest that Chlorhexidine, Listerine and Povidone-Iodine are capable of inducing a dose-dependent reduction in cellular proliferation of fibroblasts. The results presented are interesting, but to know the clinical significance, further studies are needed.

Citotoxicidade da solução aquosa de clorexidina a 3.5% em culturas de células Hep-2 (CCL - 23) / Cytotoxicity of chlorhexidine aqueous solution 3.5% in cultures of Hep-2 cells (CCL - 23)

O presente trabalho avaliou, "in vitro", os efeitos citotóxicos da solução aquosa de Clorexidina a 3,5%, pelo teste de citotoxicidade em cultivo celular, através de linhagens de células Hep-2 (CCL-23), por leitura em espectrofotômetro. Na análise estatística utilizada, o teste de Anova e os dados foram submetidos aos critérios de avaliação que constam das normas de testes de citotoxicidade número 9 da FDI, de 1980. O tempo de exposição foi de 5 minutos, o que permitiu encontrar evidências suficientes para sustentar que exista diferença estatisticamente significante entre a solução testada e os grupos controle. Através do presente estudo pode-se concluir que a solução aquosa de Clorexidina a 3,5% comportou-se como uma solução não citotóxica.

The purpose of this work was to evaluate, in vitro, the citotoxic effects of the 2,5% Chlorhexidine aquous solution by the citotoxic test in cell cultivation, through the Hep-2 (CCL-23) cell lineager by spectrofotometer reading. In the used statistical analysis, the Anova test and the data were submitted to the evaluation criterion presented in the rules of the citotoxic test number 9 of the FDI, 1980. The exposure time was 5 minutes, which provided enough evidences to support that there was a significant statistic difference between the tested solution and the control group. In the present study it was demonstrated that the Chlorhexidine aquous solution 3,5% is not a citotoxic solution.

O gluconato de clorexidina ou o álcool-iodo-álcool na anti-sepsia de campos operatórios em cäes / Chlorhexidine gluconate or alcohol-iodine-alcohol in the antisepis of surgical area in dogs

Foi comparada a efetividade da anti-sepsia de sítios operatórios em vinte e quatro animais, subdivididos em três grupos, utilizado água destilada (grupo controle), álcool-iodo-álcool (grupo I) e gluconato de clorexidina (grupo II). As amostras foram coletadas através de swab da pele, depois da tricotomia (T0), após anti-sepsia (T1) e duas horas após o uso do antiséptico(T2), e submetidas à contagem de Unidades Formadoras de Colônia (UFC)/ml. Nos três grupos, ocorreu crescimento bacteriano em T0; no T1 a reduçäo média de UFC/ml foi de 26,70j por cento para o grupo controle, 91,61 por cento para o grupo I e 96,67 por cento para o grupo II. No T2, as reduçöes nos respectivos grupos foram de 21,02 por cento, 91,56 por cento e 96,89 por cento. as duas técnicas utilizando anti-sépticos reduziram significativamente o número de bactérias da pele, tanto no T1 quanto no T2 (p< 0,05). A eqüiparidade entre os dois métodos ficou evidenciada, uma vez que näo foi encontrada diferença estatisticamente significativa entre eles (p<0,05).

Contribuiçäo para conhecimento da toxicidade aguda e crônica do digliconato de clorexidina administrado por via oral em camundongos / Contribution to the study of toxicity of chlorhexidine gluconate by oral administration in rats

Säo apresentados os resultados sobre a toxicidade do digliconato de clorexidina administrado por via oral a camundongos. Nos ensaios crônicos com a ingestäo das soluçöes a 0,02% e 0,05% em camundongos de ambos os sexos näo foi observada anormalidade no desenvolvimento ponderal, e a soluçäo a 0,02% näo interferiu na fecundidade, embora o número de filhotes tenha sido menor que no grupo testemunha. A DL50 por via oral em camundongos, foi constatada ser de 550mg/kg