Bone tissue response to an MTA-based endodontic sealer, and the effect of the addition of calcium aluminate and silver particles.

AIM: To evaluate bone tissue reactions in rats to an MTA-based endodontic sealer with and without the addition of various concentrations of C3A or C3A + Ag. METHODOLOGY: Bone tissue reactions were evaluated in 45 Wistar rats after 7, 30 and 90 days (n = 5 per period). Three surgical cavities were prepared on the right femur and filled with 0.2 mL MTA Fillapex, MTA Fillapex + C3A and C3A + Ag at various concentrations: AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), EndoSequence BC (Brasseler USA, Savannah, GA, USA) or no sealer (negative control). By the end of each experimental period, animals were randomly euthanized. The samples were histologically processed and analysed using a light microscope. The presence of inflammatory cells, fibres and hard tissue barrier formation was evaluated. Data were analysed statistically using nonparametric tests to compare the differences between groups. Multiple groups were compared using the Kruskal-Wallis and Mann-Whitney U-tests with a Bonferroni correction at P = 0.05. RESULTS: The inflammatory response significantly decreased from 30 to 90 days (P < 0.05). Fibre condensation was similar amongst the groups at 07 and 30 days after intervention (P > 0.05). At 90 days, however, fibres were absent in most specimens of EndoSequence BC Sealer, AH Plus, MTA Fillapex and the control group, whilst they were still observed in samples of the modified sealers (P < 0.05). At 90 days, all specimens of AH Plus, EndoSequence BC Sealer and control group had complete formation of hard tissue barrier. In the MTA Fillapex group, as well as in the modified sealers groups, partial deposition of mineralized tissue was noticed. CONCLUSION: The hypothesis tested that the incorporation of C3A and C3A + Ag particles to MTA Fillapex would improve bone tissue repair was partially accepted, since modified MTA Fillapex did not have the same repair potential as the commercial bioceramic material.

Impact of infected and noninfected human dentine debris on bone healing in rats.

AIM: To evaluate in vivo the bone tissue response of rats to varying amounts of infected and noninfected dentine debris. METHODOLOGY: Bone tissue reactions were evaluated histologically in 42 Wistar rats after 7, 30 and 60 days. For each animal, three surgical cavities were prepared on the femur and filled with varying amounts (5, 10 or 20 mg) of infected or noninfected dentine debris pellets. In the negative control group, the surgical cavities were not filled. At the end of each experimental period, the animals were euthanized. The samples were processed histologically and analysed using a light microscope. The presence and the severity of inflammatory reaction, as well as hard tissue deposition were evaluated. Data were subjected to statistical analysis and the effects of the dependent variables calculated using nonparametric tests Kruskal-Wallis and Mann-Whitney U with due Bonferroni corrections at P = 0.05. RESULTS: At 7 days, the presence of infected debris significantly increased the histopathological scores for neutrophils (P < 0.05), and abscess formation (P < 0.05). Noninfected debris scored significantly higher for lymphocyte infiltrate compared with the control group and infected debris (P < 0.05). Both infected and noninfected debris equally triggered eosinophil cells compared with no-dentine (P < 0.05). As for giant cells and macrophages, no difference was detected amongst the dentine groups (P > 0.05). Hard tissue deposition was similar regardless of the presence or the bacteriological status of the dentine (P = 1.00). None of the above histopathological parameters was significantly influenced by the amount of debris (P > 0.05). For all parameters evaluated, at 7 days of analysis, the inflammatory response was significantly more intense compared with 30 and 60 days (P < 0.05). Inflammatory parameters were scored similarly for the evaluated groups after 30 and 60 days (P > 0.05). However, hard tissue deposition has significantly increased after 30 days (P < 0.05). No difference was seen between 30 and 60 days of analysis (P = 1.00) for all histological parameters evaluated. CONCLUSION: The assumption that the amount of extruded debris may negatively affect the inflammatory response of bone tissue was not validated in the present in vivo animal study. Infected dentine may trigger acute inflammatory parameters especially during the first 7 days of contact with the tissue; however, in the long term, these negative effects are mitigated.

Antibiotic prescription for endodontic infections: a survey of Brazilian Endodontists.

AIM: To investigate antibiotic prescribing habits reported by Brazilian endodontists in specific clinical situations. METHODOLOGY: Brazilian endodontists (n = 13 853) were invited to answer an online questionnaire. The questionnaire consisted of two parts: the first part contained personal data such as age, gender, years of experience and location of endodontic practice; the second part included questions regarding their behaviour when prescribing antibiotics in dental practice. The subjects provided their registration number in the Regional Council of Dentistry (RCD) to prevent duplication of data. Data were collected and analysed by SPSS 17.0 (SPSS, Inc., Chicago, IL, USA). Chi-square and Fisher's exact tests were used to test the significance of possible associations (P < 0.05). RESULTS: From the 13 853 questionnaires, a total of 615 were answered (4.44%). The first-choice antibiotic was amoxicillin (81.5%), followed by amoxicillin + clavulanic acid (30.7%). For acute apical abscesses with intra- and extraoral diffuse swelling, fever and trismus, 90.1% reported they would prescribe antibiotics, whilst 88.1% reported they would prescribe antibiotics even without extraoral swelling, fever and trismus, and 20.5% would prescribe antibiotics in cases of chronic apical periodontitis, and sinus tract. The first-choice antibiotics varied by age of dentist (P < 0.001) and time elapsed since their endodontic graduation (P = 0.001). CONCLUSIONS: Many endodontists reported prescribing antibiotics in situations where they would not be indicated. Likewise, the general administration of antibiotics was longer in duration than necessary, reinforcing the need of continuous education regarding the use of antibiotics.

In vitro antibacterial action of Tetraclean, MTAD and five experimental irrigation solutions.

AIM: To investigate the antibacterial effect of Tetraclean, MTAD and five experimental irrigants using both direct exposure test with planktonic cultures and mixed-species in vitro biofilm model. METHODOLOGY: Tetraclean, MTAD and five experimental solutions that were modifications of existing formulae including MTAD + 0.01% cetrimide (CTR), MTAD + 0.1% CTR, MTAC-1 (Tween 80 replaced by 0.01% CTR in MTAD), MTAC-2 (Tween 80 replaced by 0.1% CTR) and MTAD-D (MTAD without the Tween 80 and no CTR added) were used as disinfectants in the experiments. In the direct exposure test, a suspension of Enterococcus faecalis was mixed with each of the solutions. After 0.5, 1, 3 and 10 min, an inactivator was added and the number of surviving bacteria was calculated. A mixed-species biofilm from subgingival plaque bacteria was grown in brain heart infusion broth in anaerobic conditions on synthetic hydroxyapatite discs. Two-week-old biofilms were exposed to the solutions for 0.5, 1 and 3 min. The samples were observed by confocal laser scanning microscopy after bacterial viability staining. The scans were quantitatively analysed, and the volume of killed cells of all cells was calculated for each medicament. RESULTS: Tetraclean and MTAC-2 (0.1% CTR) killed planktonic E. faecalis in <30 s. Complete killing of bacteria required 1 min by MTAC-1, 3 min by MTAD + 0.1% CTR and 10 min by MTAD, MTAD-D and MTAD + 0.01% CTR. In the biofilm test, there were significant differences in microbial killing between the different solutions and times of exposure (P < 0.005). MTAC-2 showed the best performance, killing 71% of the biofilm bacteria in 3 min, followed by MTAC-1 and Tetraclean. MTAD and the three MTAD modifications demonstrated the lowest antibacterial activity. CONCLUSION: Tetraclean was more effective than MTAD against E. faecalis in planktonic culture and in mixed-species in vitro biofilm. CTR improved the antimicrobial properties of the solutions, whereas Tween 80 seemed to have a neutral or negative impact on their antimicrobial effectiveness.

Anthelmintic resistance in Creole horses in the South of Rio Grande do Sul, Brazil / [Resistência anti-helmíntica em equinos da raça Crioula no sul do Rio Grande do Sul, Brasil]

The objective of the study was to evaluate the antiparasitic resistance against horse nematodes in the South of Rio Grande do Sul, Brazil. The results concerning the tests of anthelmintic efficacy on horses, stored in the database of the Parasitic Diseases Study Group (GEEP) - Veterinary Faculty, at the Federal University of Pelotas (UFPel), were carried out in the laboratory from 2018 to 2019. Stool samples were received from farms with breeding of adult female and male Criollo horses naturally infected, located in municipalities in the country's southern region. The antiparasitic agents tested were Triclorfon + Fenbendazole, Closantel + Albendazole, Ivermectin + Praziquantel, Fenbendazole, Ivermectin, Doramectin, Mebendazole and Moxidectin. Techniques such as Gordon and Whitlock, Coproculture and Fecal Egg Count Reduction Test were performed. Of all the antiparasitic drugs tested, it was observed that only treatments with Ivermectin 2% showed desired values. The observed results indicate that resistance to macrocyclic lactones is usual in equine parasites in this Brazilian region, despite the results with isolated Ivermectin.(AU)

O objetivo deste estudo é avaliar a resistência antiparasitária contra nematodeos de equinos no sul do Rio Grande do Sul, Brasil. Os resultados referentes aos testes de eficácia anti-helmíntica em cavalos, armazenados no banco de dados do Grupo de Estudos de Doenças Parasitárias (GEEP) - Faculdade de Veterinária, da Universidade Federal de Pelotas (UFPel), foram realizados em laboratório, no período de 2018 a 2019. Amostras de fezes foram recebidas de fazendas com criação de cavalos Crioulos adultos fêmeas e machos naturalmente infectados, localizadas em municípios da região Sul do país. Os agentes antiparasitários testados foram triclorfon + fenbendazol, closantel + ivermectina + praziquantel, fenbendazol, ivermectina, doramectina, mebendazol e moxidectina. Técnicas como Gordon e Whitlock, coprocultura e teste de redução da contagem de ovos fecais foram realizadas. De todos os antiparasitários testados, observou-se que apenas os tratamentos com ivermectina 2% apresentaram os valores desejados. Os resultados indicam que a resistência às lactonas macrocíclicas é comum em parasitas equinos nessa região brasileira, apesar dos resultados com ivermectina isolada.(AU)

Frequency of gastrointestinal parasites in Creole horses from the Southern Rio Grande do Sul / Frequência de parasitos gastrintestinais em equinos da raça Crioula do sul do Rio Grande do Sul

A criação de equinos brasileira movimenta anualmente cerca de R$ 16,15 bilhões e impulsiona o setor econômico primário do país. O mercado de animais da raça Crioula vem se expandindo devido ao seu alto potencial zootécnico. No Rio Grande do Sul, a criação é tipicamente extensiva, aliada, muitas vezes, à alta densidade animal, o que favorece as constantes infecções por diversos parasitos. O objetivo deste estudo foi analisar retrospectivamente a frequência de parasitos gastrointestinais em cavalos da raça Crioula naturalmente infectados na região sul do Rio Grande do Sul. Foram utilizadas 585 amostras de fezes de equinos da raça Crioula, adultos, de ambos os sexos, recebidas de criatórios e centros reprodutivos localizados na região. Do total de amostras, 89,74% (525/585) foram positivas para algum helminto. Em 57,60% (337/585) das amostras, observaram-se somente ovos da família Strongylidae. Infecções por Parascaris spp. e Strongyloides sp., apresentaram frequências de 2,22% (13/585) e 1,53% (9/585), respectivamente. Assim, pode-se concluir que os parasitos mais frequentes na população equina da região sul do RS pertencem à família Strongylidae.(AU)