Bleaching gel volume influences hydrogen peroxide diffusion, inflammation, and the presence of nitric oxide in the pulp tissue: in vitro and in vivo model.

OBJECTIVE: To assess whether bleaching gel volume influences chromatic changes, hydrogen peroxide (HP) diffusion, inflammation, and oxidative stress in the pulp tissue. METHODOLOGY: A total of 60 bovine teeth were divided into four groups, according to bleaching gel volume (n=15): without gel (WG); V30 (30 µL of 35% HP); V60 (60 µL); and V120 (120 µL). HP diffusion analysis was performed in the first session (T1). Chromatic changes (ΔE, ΔE00, and WID) were assessed after the first (T1), second (T2), third (T3) sessions, and 15 d (T4) after the end of treatment. Moreover, 20 rats were randomly divided into four groups (n=10) and their upper first molars were treated with different gel volumes: control (no treatment); V2 (2 µL of 17.5% HP); V4 (4 µL); and V8 (8 µL). After 24 h, rats were euthanized and the specimens processed for histological and immunohistochemical (nitric oxide synthase) evaluation. Data were analyzed using the Wilcoxon and Mann-Whitney tests (p<0.05). RESULTS: In vitro (bovine teeth), chromatic changes were not influenced by bleaching gel volume, showing similar values in all groups and sessions, except for the control group (p<0.05). The V120 group had the highest HP diffusion values (p<0.05). In vivo (pulp tissue), the V4 and V8 groups showed the highest inflammatory infiltrate in the pulp and significant oxidative stress (p<0.05). CONCLUSION: The adverse effects on the dental pulp related to HP diffusion, pulp inflammation, and oxidative stress depend on bleaching gel volume, while the bleaching effect is not proportional to the volume used.

Experimental Medications for Using in Endodontics: Cytotoxicity, Genotoxicity and Mutagenesis Analysis / Medicamentos Experimentais para Uso em Endodontia: Análise de Citotoxicidade, Genotoxicidade E Mutagênese

The objective was to evaluate the cytotoxic, genotoxic and mutagenic properties of two experimental medication in Endodontics. For cytotoxic evaluation, fibroblast and osteoblast cells (1x104 cells/well) were plated and divided into groups conforming to the product added in culture medium: EM1 - 20 µL of experimental medication 1 (EM1); EM2 - 20 µL of experimental medication 2 (EM2); VE - 20 µL of vehicle used in medications; C - without product. The MTT assay was performed at 24, 48 e 72 hours for cytotoxic analysis. For genotoxic and mutagenic evaluation, 42 male rats were used. After 1 and 7 days of tubes containing EM1 or EM2, or empty (NC) were subcutaneously implanted, and after 1 day, a single dose of cyclophosphamide (CY) to be applied, the bone marrow was collected and submitted to comet and micronuclei assay. The significance level of 5% was considered for all statistical analysis. The viability of fibroblasts was <70% to both medications at 24h, and EM1 at 72h; at 72h, the proliferation cells was observed in EM2 (>100%). Both medications were non-cytotoxic to osteoblasts, and the EM2 stimulate the cell proliferation at 72h. The damage frequency of CY was statistically similar to EM1 and different to EM2 (p<0.05). The number of micronuclei was insignificant to EM1 and EM2 and no difference to group NC (p>0.05). Despite the absence of mutagenesis and non-cytotoxicity to osteoblasts, the EM1 was cytotoxic and genotoxic to fibroblasts. The EM2 was non-genotoxic, non-cytotoxic and nonmutagenic. (AU)

O objetivo foi avaliar as propriedades citotóxicas, genotóxicas e mutagênicas de dois medicamentos experimentais em Endodontia. Para avaliação citotóxica, células fibroblásticas e osteoblásticas (1x104 células/poço) foram plaqueadas e divididas em grupos de acordo com o produto adicionado no meio de cultura: EM1 - 20 µL da medicação experimental 1 (EM1); EM2 - 20 µL da medicação experimental 2 (EM2); VE - 20 µL de veículo utilizado em medicamentos; C ­ sem produto. O ensaio MTT foi realizado aos 24, 48 e 72 horas para análise citotóxica. Para avaliação genotóxica e mutagênica foram utilizados 42 ratos machos. Após 1 e 7 dias foram implantados por via subcutânea tubos contendo EM1 ou EM2, ou vazios (NC), e após 1 dia, foi aplicada dose única de ciclofosfamida (CY), a medula óssea foi coletada e submetida ao ensaio de cometa e micronúcleos. O nível de significância de 5% foi considerado para todas as análises estatísticas. A viabilidade dos fibroblastos foi <70% para ambas as medicações às 24h e ao EM1 às 72h; às 72h, a proliferação de células foi observada em EM2 (>100%). Ambas as medicações foram não citotóxicas para os osteoblastos, e o EM2 estimulou a proliferação celular às 72h. A frequência de dano do CY foi estatisticamente semelhante ao EM1 e diferente do EM2 (p<0,05). O número de micronúcleos foi insignificante para EM1 e EM2 e não houve diferença para o grupo NC (p>0,05). Apesar da ausência de mutagênese e não citotoxicidade para osteoblastos, o EM1 foi citotóxico e genotóxico para fibroblastos. O EM2 era não genotóxico, não citotóxico e não mutagênico. (AU)

Bleaching gel volume influences hydrogen peroxide diffusion, inflammation, and the presence of nitric oxide in the pulp tissue: in vitro and in vivo model

Abstract Objective To assess whether bleaching gel volume influences chromatic changes, hydrogen peroxide (HP) diffusion, inflammation, and oxidative stress in the pulp tissue. Methodology A total of 60 bovine teeth were divided into four groups, according to bleaching gel volume (n=15): without gel (WG); V30 (30 µL of 35% HP); V60 (60 µL); and V120 (120 μL). HP diffusion analysis was performed in the first session (T1). Chromatic changes (ΔE, ΔE00, and WID) were assessed after the first (T1), second (T2), third (T3) sessions, and 15 d (T4) after the end of treatment. Moreover, 20 rats were randomly divided into four groups (n=10) and their upper first molars were treated with different gel volumes: control (no treatment); V2 (2 μL of 17.5% HP); V4 (4 μL); and V8 (8 μL). After 24 h, rats were euthanized and the specimens processed for histological and immunohistochemical (nitric oxide synthase) evaluation. Data were analyzed using the Wilcoxon and Mann-Whitney tests (p<0.05). Results In vitro (bovine teeth), chromatic changes were not influenced by bleaching gel volume, showing similar values in all groups and sessions, except for the control group (p<0.05). The V120 group had the highest HP diffusion values (p<0.05). In vivo (pulp tissue), the V4 and V8 groups showed the highest inflammatory infiltrate in the pulp and significant oxidative stress (p<0.05). Conclusion The adverse effects on the dental pulp related to HP diffusion, pulp inflammation, and oxidative stress depend on bleaching gel volume, while the bleaching effect is not proportional to the volume used.

Influence of violet LED associated or not with peroxide gel on inflammation, mineralization, and collagen fiber maturation in dentin and pulp tissue.

OBJECTIVES: To evaluate the influence of violet LED, associated or not with a 17.5% hydrogen peroxide (HP) bleaching gel, on inflammation, mineralization in pulp tissue, and collagen fiber maturation in dentin and pulp tissue. MATERIALS AND METHODS: The maxillary molars of eighty Wistar rats were distributed into four groups (n = 10): CONT - without treatment; HP - 30 min application of 17.5% HP; LED - 20 min application of violet LED; and HP+LED - application of PH and violet LED. Rats were euthanized and jaws were processed for histologic and immunohistochemical evaluation (IL-17, IL-23, and osteocalcin) and picrosirius red immediately after (T0), and at 7 (T1), 15 (T2), and 30 days (T3) post-treatment, with Wilcoxon, Mann-Whitney, paired T-test, and T-test (α = 0.05). RESULTS: HP and HP+LED presented necrosis and severe inflammatory infiltrate. When compared to CONT group, LED presented severe osteocalcin (OCN) immunostaining in T2 and less immature fibers in T2 and T3. CONCLUSION: The violet LED caused no severe damage to the pulp tissue, increased IL-17 and IL-23 expression in T0 when associated with HP, and had no influence on pulp tissue mineralization, besides accelerating the maturation of collagen fibers of dentin. CLINICAL RELEVANCE: Violet LED therapy induced no inflammation in the pulp tissue of rats and played no role in pulp tissue fibrosis, besides accelerating the maturation of dentin collagen fibers.

Estudo in vitro da ação antimicrobiana de medicações intracanal experimentais sobre biofilmes de Enterococcus faecalis / In vitro study of the antimicrobial action of experimental intracanal medications on Enterococcus faecalis biofilm

Introdução: A eliminação do Enterococcus faecalis dos canais radiculares é fundamental para o sucesso do tratamento endodôntico, uma vez que esses microrganismos são de difícil eliminação, principalmente quando organizados em forma de biofilmes. A busca por drogas ou suas combinações que possam eliminar esses microrganismos é um dos principais objetivos terapêuticos. Objetivo: O presente estudo avaliou a ação antimicrobiana de medicações intracanal experimentais sobre biofilmes de Enterococcus faecalis. Métodos: Quarenta dentes bovinos unirradiculares foram utilizados; suas coroas foram seccionadas e as raízes foram instrumentadas e esterilizadas. As raízes foram contaminadas com suspensão contendo Enterococcus faecalis, mantidas em estufa a 37°C por 30 dias e divididas em quatro grupos, de acordo com a medicação intracanal: GI) medicação experimental 1 (clorexidina [CHX] 0,2%/metronidazol, doxiciclina); GII) medicação experimental 2 (CHX 0,2%/metronidazol, minociclina); GIII) clorexidina a 2% (CHX 2%); e GIV) solução salina. As raízes foram seladas e mantidas em estufa por 7 dias, em tubos contendo TSB. Dentina foi coletada e semeada por 24 h, para formação de UFCs. Os valores obtidos foram comparados pelos testes ANOVA e Tukey (p<0,05). Quando comparados os resultados, não houve diferenças entre os Grupos I, II e III; no entanto, eles foram significativamente diferentes do Grupo IV. Conclusão: As medicações intracanal experimentais exerceram ação antimicrobiana sobre biofilmes de Enterococcus faecalis (AU).

Background: The elimination of Enterococcus faecalis of the root canals is fundamental for endodontic success, since these microorganisms are difficult to killed, especially when organized in biofilms. The search for drugs or their combinations that can eliminate these microorganisms is one of the main therapeutic aim. This study evaluated the antimicrobial action of experimental intracanal medications on Enterococcus faecalis biofilms. Methods: Forty uniradicular bovine teeth were used; their crowns were removed, and the roots were instrumented and sterilized. The roots were contaminated with suspension containing Enterococcus faecalis and kept in an oven at 37°C for 30 days. The roots were divided into 4 groups according to the intracanal medication: I- experimental medication 1 (0.2% CHX/metronidazole/ doxycycline); II- experimental medication 2 (0.2% CHX/ metronidazole/minocycline), III- 2% chlorhexidine (2% CHX), and IV- saline solution. The roots were sealed and kept in tubes containing TSB in an oven for 7 days. Dentin was collected and seeded for 24 h for perform of CFUs. The values obtained were compared using ANOVA and Tukeys tests (p<0.05). When comparing the results, there were no differences among groups I, II and III; however, they were significantly different from group IV. Conclusion: The experimental intracanal medications exerted an antimicrobial action on Enterococcus faecalis biofilms (AU).

Influence of anti-allergic drugs used systemically on the process of root resorption during delayed tooth replantation: A study in rats.

BACKGROUND/AIM: Anti-allergic drugs can inhibit the hard tissue resorption process, and due to similarities between root resorption and bone mechanisms, it can be inferred that these drugs may also control root resorption. The aim of this study was to analyze the effects of anti-allergic drugs used systemically on the process of root resorption following delayed tooth replantation. MATERIALS AND METHODS: Thirty-two maxillary right incisors of rats were extracted and subsequently replanted. Rats were divided into four groups according to the anti-allergic drug administered: the rats in groups DEX, Q, and MO were treated systemically with dexamethasone phosphate, quercetin, and montelukast, respectively, and no systemic medication was administered to rats in group C. After 60 days, the animals were euthanized, and the specimens were processed for histomorphometric and immunohistochemical analyses. Statistical significance was set at P < .05. RESULTS: There were no significant differences between the groups in terms of inflammatory resorption, replacement resorption, or presence of tartrate-resistant acid phosphatase. In terms of events occurring in the periodontal ligament space, there was a difference between groups Q and MO due to the presence of dental ankylosis and inflammatory connective tissue (P < .05). A difference in inflammatory cells was also observed through CD45 immunolabeling between the DEX and Q groups when compared to the C group (P < .05). CONCLUSION: The systemic administration of anti-allergic drugs did not have an effect on the process of root resorption following delayed tooth replantation.