Bis-GMA-containing resin-composites undergo biodegradation by human saliva derived esterases, yielding Bis-hydroxy-propoxy-phenyl-propane (Bis-HPPP). The hypothesis of this study is that the exposure of dental restorations to saliva-like esterase activities accelerates marginal bacterial microleakage. Resin-composites (Scotchbond, Z250, 3M) bonded to human dentin were incubated in either buffer, or dual-esterase media (pseudocholinesterase/cholesterol-esterase; PCE-CE) with activity levels simulating that of human saliva, for up to 90 days. Incubation solutions were analyzed for resin degradation by-products using high-performance liquid-chromatography. Post-incubation, specimens were suspended in a chemostat-based biofilm fermentor cultivating Streptococcus mutans NG8 for 7 days. Bacterial microleakage was assessed by confocal laser scanning microscopy. Bis-HPPP production, as well as depth and spatial volume of bacterial cell penetration within the interface increased with incubation time. Biodegradation and bacterial microleakage were significantly higher for 30 and 90 day PCE-CE vs. buffer incubated groups (p<0.05). Conclusion: An overall decline in interfacial integrity was observed following exposure to human saliva-like esterases over time.

Bis-GMA-containing resin-composites undergo biodegradation by human saliva derived esterases, yielding Bis-hydroxy-propoxy-phenyl-propane (Bis-HPPP). The hypothesis of this study is that the exposure of dental restorations to saliva-like esterase activities accelerates marginal bacterial microleakage. Resin-composites (Scotchbond, Z250, 3M) bonded to human dentin were incubated in either buffer, or dual-esterase media (pseudocholinesterase/cholesterol-esterase; PCE-CE) with activity levels simulating that of human saliva, for up to 90 days. Incubation solutions were analyzed for resin degradation by-products using high-performance liquid-chromatography. Post-incubation, specimens were suspended in a chemostat-based biofilm fermentor cultivating Streptococcus mutans NG8 for 7 days. Bacterial microleakage was assessed by confocal laser scanning microscopy. Bis-HPPP production, as well as depth and spatial volume of bacterial cell penetration within the interface increased with incubation time. Biodegradation and bacterial microleakage were significantly higher for 30 and 90 day PCE-CE vs. buffer incubated groups (p<0.05). Conclusion: An overall decline in interfacial integrity was observed following exposure to human saliva-like esterases over time.

Três dos principais tipos de implantes disponíveis no mercado são: o hexágono externo, o hexágono interno e o cone morse. Um microespaço, presente entre o implante e o intermediário protético, permite a penetração bacteriana e colonização do interior do implante. Esse microespaço, juntamente com a colonização bacteriana, tem sido associado com a perda óssea ao redor dos implantes, característica da periimplantite. O objetivo desse trabalho foi comparar a possível contaminação bacteriana nesses três tipos de implantes, em um período de 24 horas, semelhante ao que acontece na condição de carga imediata. Para tal, foram utilizados 10 implantes de cada tipo, com seus respectivos intermediários protéticos, sendo o Grupo 1 de implantes Hexágono Externo (HE), Grupo 2 de Hexágono Interno (HI) e Grupo 3 de Cone Morse (CM). No interior de cada implante foram inoculados 2L de meio de cultura (BHI). Os espécimes foram depositados individualmente em tubos de ensaio contendo 4 mL de BHI estéril. Após um teste de esterilidade, 100L de BHI contendo Enterococcus faecalis foram inoculados em cada tubo. Após 24 horas em meio contendo bactérias, os espécimes foram removidos, desinfectados e reabertos. Com um cone de papel estéril, o material do interior dos implantes foi coletado e colocado em meio de cultura para avaliar a possível passagem de bactérias do meio externo para o interno dos implantes. O teste foi repetido por mais duas vezes (Teste I, II e III), com o cuidado de se lavar e esterilizar em autoclave os espécimes. Os resultados foram tabulados e o teste exato de Fisher foi aplicado com o nível de significância de 5%. Os resultados do teste I mostraram a contaminação de 8 implantes HE, 4 implantes HI e 2 implantes CM, sendo a contaminação no grupo HE estatisticamente significante maior que nos grupos HI e CM; o teste II mostrou a contaminação de 7 implantes HE, 4 implantes HI e 4 implantes CM, não havendo diferenças estatisticamente significantes; o teste III mostrou a contaminação de 10 implantes HE, 7 implantes HI e 3 implantes CM, revelando diferenças estatisticamente significantes entre o grupo HE e CM. Concluise, portanto, que após um período de 24 horas, houve contaminação bacteriana em todos os grupos avaliados, sendo estatisticamente maior no grupo 1. / Three main types of implants available in the market are: external hexagonal, internal hexagonal and morse-taper. A microgap, present between the implant and the abutment, enables bacterial penetration and colonization of the interior of the implant. This microgap, associated with bacterial colonization, has been related with bone loss around the implants, present in periimplantitis . The aim of this study was to compare the possible bacterial contamination in these three types of implants in a 24 hour period, similarly with immediate loading. 10 implants of each type, with their abutments, were used. The implants of Group 1 were external hexagonal (HE) type, Group 2 were Internal Hexagonal (HI) type and Group 3, morse-taper type(MC). 2 µL of brain-heart infusion (BHI) broth were added into each implant. The specimens were placed individually in glass culture tubes containing 4 mL of sterile BHI broth. After a test to assure sterility, 100 µL of BHI broth containing Enterococcus faecalis were inoculated in each tube. After 24 hours, the specimens were removed, disinfected and reopened. With a sterile paper cone, the material inside the implants were collected and placed in BHI to evaluate the possible passage of bacteria from the outside to the internal side of the implant. The test was repeated two times more (Test I, II and III). The Fisher exact test was used to compare the number of contaminated implants in each group, at a significance level of 5%. The results of test I showed contamination of 8 HE implants, 4 HI implants and 2 CM implants. The contamination in the HE group was statistically higher than CM and HI groups. Test II revealed contamination of 7 HE implants, 4 HI implants and 4 CM implants. No statistically significant differences were observed. Test III showed contamination of 10 HE implants, 7 HI implants and 3 CM implants, revealing statistically significant differences between HE and CM groups. It can be concluded that after a period of 24 hours, there was bacterial leakage in all groups studied, with statistically higher contamination in group 1.

Três dos principais tipos de implantes disponíveis no mercado são: o hexágono externo, o hexágono interno e o cone morse. Um microespaço, presente entre o implante e o intermediário protético, permite a penetração bacteriana e colonização do interior do implante. Esse microespaço, juntamente com a colonização bacteriana, tem sido associado com a perda óssea ao redor dos implantes, característica da periimplantite. O objetivo desse trabalho foi comparar a possível contaminação bacteriana nesses três tipos de implantes, em um período de 24 horas, semelhante ao que acontece na condição de carga imediata. Para tal, foram utilizados 10 implantes de cada tipo, com seus respectivos intermediários protéticos, sendo o Grupo 1 de implantes Hexágono Externo (HE), Grupo 2 de Hexágono Interno (HI) e Grupo 3 de Cone Morse (CM). No interior de cada implante foram inoculados 2L de meio de cultura (BHI). Os espécimes foram depositados individualmente em tubos de ensaio contendo 4 mL de BHI estéril. Após um teste de esterilidade, 100L de BHI contendo Enterococcus faecalis foram inoculados em cada tubo. Após 24 horas em meio contendo bactérias, os espécimes foram removidos, desinfectados e reabertos. Com um cone de papel estéril, o material do interior dos implantes foi coletado e colocado em meio de cultura para avaliar a possível passagem de bactérias do meio externo para o interno dos implantes. O teste foi repetido por mais duas vezes (Teste I, II e III), com o cuidado de se lavar e esterilizar em autoclave os espécimes. Os resultados foram tabulados e o teste exato de Fisher foi aplicado com o nível de significância de 5%. Os resultados do teste I mostraram a contaminação de 8 implantes HE, 4 implantes HI e 2 implantes CM, sendo a contaminação no grupo HE estatisticamente significante maior que nos grupos HI e CM; o teste II mostrou a contaminação de 7 implantes HE, 4 implantes HI e 4 implantes CM, não havendo diferenças estatisticamente significantes; o teste III mostrou a contaminação de 10 implantes HE, 7 implantes HI e 3 implantes CM, revelando diferenças estatisticamente significantes entre o grupo HE e CM. Concluise, portanto, que após um período de 24 horas, houve contaminação bacteriana em todos os grupos avaliados, sendo estatisticamente maior no grupo 1. / Three main types of implants available in the market are: external hexagonal, internal hexagonal and morse-taper. A microgap, present between the implant and the abutment, enables bacterial penetration and colonization of the interior of the implant. This microgap, associated with bacterial colonization, has been related with bone loss around the implants, present in periimplantitis . The aim of this study was to compare the possible bacterial contamination in these three types of implants in a 24 hour period, similarly with immediate loading. 10 implants of each type, with their abutments, were used. The implants of Group 1 were external hexagonal (HE) type, Group 2 were Internal Hexagonal (HI) type and Group 3, morse-taper type(MC). 2 µL of brain-heart infusion (BHI) broth were added into each implant. The specimens were placed individually in glass culture tubes containing 4 mL of sterile BHI broth. After a test to assure sterility, 100 µL of BHI broth containing Enterococcus faecalis were inoculated in each tube. After 24 hours, the specimens were removed, disinfected and reopened. With a sterile paper cone, the material inside the implants were collected and placed in BHI to evaluate the possible passage of bacteria from the outside to the internal side of the implant. The test was repeated two times more (Test I, II and III). The Fisher exact test was used to compare the number of contaminated implants in each group, at a significance level of 5%. The results of test I showed contamination of 8 HE implants, 4 HI implants and 2 CM implants. The contamination in the HE group was statistically higher than CM and HI groups. Test II revealed contamination of 7 HE implants, 4 HI implants and 4 CM implants. No statistically significant differences were observed. Test III showed contamination of 10 HE implants, 7 HI implants and 3 CM implants, revealing statistically significant differences between HE and CM groups. It can be concluded that after a period of 24 hours, there was bacterial leakage in all groups studied, with statistically higher contamination in group 1.

The commonly used materials in endodontic treatment lack the ability to prevent microleakage, which can lead to failure of the treatment. This study aimed to evaluate the effectiveness of adding Coltosol plug in preventing coronal microleakage in endodontically treated teeth using the in vitro dye penetration method. Ten single canal plastic teeth were prepared and obturated using the SG-endodontic technique. The teeth were randomly divided into two groups, with and without Coltosol plug, and dye penetration was measured at 6 and up to 72 hours. No difference in leakage was observed after 6 and 72 hours. Specimens with a plug of Coltosol showed similar dye penetration compared to the ones with only Gutta-percha and sealer.