Whole-blood cultures from patients with chronic periodontitis respond differently to Porphyromonas gingivalis but not Escherichia coli lipopolysaccharide.

BACKGROUND: Porphyromonas gingivalis lipid A heterogeneity modulates cytokine expression in human cells. This study investigates the effects of two lipid A isoforms of P. gingivalis, lipopolysaccharide (LPS)1435/1449 and LPS1690, on the secretion of proinflammatory and regulatory cytokines in total blood cultures from patients with and without chronic periodontitis (CP). METHODS: A cross-sectional study was conducted in 38 systemically healthy individuals divided in two groups: 1) the CP group (n = 19), in which patients were diagnosed with CP; and 2) the no periodontitis (NP) group (n = 19), which included control patients without CP. Blood samples were collected from all patients, and whole-blood cell cultures (WBCCs) were stimulated for 48 hours with P. gingivalis LPS1435/1449 and LPS1690 and Escherichia coli LPS. Unstimulated WBCCs served as negative controls. The secretion of interferon-γ (IFN-γ), interleukin-10 (IL-10), and transforming growth factor-ß (TGF-ß) was detected in WBCC supernatants by enzyme-linked immunosorbent assays. RESULTS: E. coli LPS significantly increased the expression of all cytokines in WBCCs from both the NP and CP groups when compared to non-stimulated cells (control treatment). P. gingivalis LPS preparations increased IFN-γ levels in the CP group but not in the NP group when compared with controls (P <0.05). P. gingivalis LPS preparations also increased IL-10 and TGF-ß levels in both CP and NP groups, but P. gingivalis LPS1690 showed a three-fold increase on IL-10 production in the NP group (P <0.05) when compared to P. gingivalis LPS1435/144. CONCLUSIONS: These data demonstrate that WBCC cell populations obtained from healthy individuals and patients with CP may differ in the cytokine response to P. gingivalis but not E. coli LPS. This is consistent with the notion that CP alters the systemic WBCC response and that this can be detected by the different P. gingivalis LPS structures.

Avaliação histométrica em ratos do efeito da fumaça da cannabis sativa (maconha) no reparo ósseo ao redor de implantes de titânio / A histometric study in rats about the effects of Cannabis sativa (marijuana) in bone filling around titanium implants

[Objetivos] Este estudo visa fazer uma revisão de literatura sobre os principais aspectos relacionados à ação da fumaça da Cannabis sativa (maconha) no reparo ósseo. [Material e métodos] Após anestesia geral, um implante de titânio com superfície usinada (2,2mm x 4,0mm) foi posicionado em uma das tíbias de 30 ratos machos e adultos da raça Wistar. Os animais foram aleatoriamente e igualmente divididos em 2 grupos experimentais. O Grupo A foi utilizado como controle e os ratos receberam apenas a colocação dos implantes. O Grupo B foi submetido ao mesmo procedimento, contudo sofreu também exposição à fumaça da Cannabis sativa durante três períodos diários de 8 minutos durante 60 dias. Os animais foram mortos 60 dias após a colocação dos implantes. As secções não descalcificadas da tíbia foram dissecadas e avaliadas histometricamente quanto ao preenchimento ósseo nos limites das roscas de cada implante; à extensão de contato direto osso-implante e em relação à densidade óssea a 500μm do implante. Médias representativas de cada grupo foram obtidas e comparadas estatisticamente pelo teste T Student (α=0,05). [Resultados] Os achados demonstraram um efeito deletério significante da fumaça da maconhano reparo ósseo ao redor de implantes, levando a uma diminuição na quantidade de tecido ósseo em contato direto com o implante, assim como na área óssea dentro dos limites das roscas dos implantes e na área de tecido ósseo a 500μm do implante. [Conclusões] Considerando as limitações do presente estudo, a inalação da fumaça de Cannabis sativa tem uma repercussão deletéria no reparo ósseo ao redor de implantes de titânio colocados em tíbias de ratos. Esses efeitos podem ser considerados durante a avaliação dos resultados sucesso/fracasso dos implantes.

[Purpose] This study aims to make a review of literature on the majors aspects related to the action of the smoke of Cannabis sativa (marijuana) in bone repair. [Materials and Methods] After general anesthesia, one screw-shaped pure titanium implant (2,2mm x 4,0mm), was placed in one tibia of 30 male Wistar rats. The animals were randomly and equally divided in two experimental groups. Group A was used as control and the rats received only the placing of implants. Group B was submitted to the same procedure and also was exposed to Cannabis sativa’s smoke inhalation for 8 minutes, three times a day during 60 days. The animals were sacrificed 60 days after implant placement. Undecalcified tibia’s sections were dissected and appraised histometrically considering bone filling around each spiral’s limit of every implant, extension of direct contact between bone and implant and bone density in a 500μm wide-zone lateral to the implant. [Results] Representative means of each group were obtained and compared statistically using Student-t test (α=0,05). [Results] The findings showed a significant negative impact of marijuana smoke inhalation on bone filling around titanium implants leading to a decrease in bone density, as well as in the extension of bone to implant contact and on bone area whitin the limits of threads. [Conclusions] Considering the limitations of the present study, the Cannabis sativa smoke inhalation may represent a deleterious impact on bone healing around titanium implants in rats tibiaes.These effects should be a new concern for implant success/failure.

Low- and high-yield cigarette smoke inhalation potentiates bone loss during ligature-induced periodontitis.

BACKGROUND: It is well recognized that cigarette consumption is a strong risk factor for periodontitis. Tobacco companies have developed a cigarette with low levels of toxic compounds; however, its effect on periodontium has not been investigated. The aim of this study was to verify the impact of smoke produced by low- and high-yield cigarettes on bone loss resulting from ligature-induced periodontitis. METHODS: A total of 36 male Wistar rats were used in the study. A ligature was placed around one of the mandibular first molars (ligated teeth) of each animal, and they were assigned randomly to one of three groups: group 1: control (N = 10), group 2: 30 days' inhalation of smoke produced by high-yield cigarettes (N = 13), and group 3: 30 days' inhalation of smoke produced by low-yield cigarettes (N = 13). The animals were sacrificed 30 days after ligature placement, and the specimens were processed for decalcified sections. RESULTS: Intergroup analysis of unligated teeth (without periodontal disease) did not show a significant difference regarding periodontal ligament area (2.40 +/- 0.5 mm(2), 2.72 +/- 0.7 mm(2), and 2.61 +/- 0.4 mm(2) for groups 1, 2, and 3, respectively; P >0.05). Conversely, significant differences were noted in ligated teeth (with periodontitis); bone loss was directly proportional to the level of toxic compounds in the cigarettes (5.74 +/- 0.5 mm(2), 7.40 +/- 0.50 mm(2), and 6.51 +/- 0.50 mm(2) for groups 1, 2, and 3, respectively; P <0.05). CONCLUSION: Low- and high-yield cigarettes potentiated bone loss during experimental periodontitis in a directly proportional fashion.