Assessment of the stresses produced on the bone implant/tissue interface to the different insertion angulations of the implant - a three-dimensional analysis by the finite elements method.

BACKGROUND: The present study aimed to assess the stresses produced on the surface of the bone tissue around dental implants with three different insertion angulations subjected to axial and oblique loading. MATERIAL AND METHODS: The study was created according to the recommendations of the Checklist for Reporting In-vitro Studies (CRIS). The Straumann™ bone level RC (4.1 x 10 mm) implant, Cone Morse connection (CM), RC Straumann Variobase™ with abutment (3.5 mm) was placed in the region of element 16, with the platform positioned at the height of the bone crest. Three assessment models were produced: model M1 or control - implant perpendicular to the bone crest; model M2 - implant angulated at 17° relative to the bone crest; and model M3 - implant angulated at 30° relative to the bone crest. The masticatory loads were simulated with 100 N of intensity and two loading patterns (axial and oblique) were applied to each model. Then, the models were exported to the finite elements simulation software Ansys Workbench V19.2 (Ansys Inc., Canonsburg, PA, USA). To assess the finite elements, qualitative and quantitative analyses were performed. RESULTS: It was observed that, under axial loading, qualitatively, the peaks occurred in the cavosurface region, palatal aspect in M1 and M2, and buccal aspect in M3. Quantitatively, the greatest angulation resulted in a low stress peak. Under oblique loading, qualitatively, the peaks occurred in the cavosurface region, buccal aspect in the three groups. Quantitatively, the greatest angulation of the implant resulted in an increase in stress peaks on the buccal aspect. CONCLUSIONS: Under axial loading, the three insertion angulations of the implant - M1, M2, and M3 - were clinically viable. When subjected to oblique loading, the 30° angulation (M3) suggested a significant risk of bone loss and it was contraindicated. Key words:Finite element analysis, dental implants, load support.

Associação entre periodontite e doença pulmonar / Association between periodontitis and lung disease

Objetivo: Verificar a associação entre a doença periodontal e a doença pulmonar, a partir de um levantamento epidemiológico, caso e controle, em pacientes que frequentaram o pronto atendimento da Fundação Hospital Adriano Jorge, no período de junho de 2006 a fevereiro de 2007, na cidade de Manaus, Amazonas, Brasil. Métodos: A amostra foi composta por 140 pacientes, sendo que pacientes com pneumonia adquirida na comunidade esteve presente em 60% (n = 70) e a doença pulmonar obstrutiva crônica em 40% (grupo-caso) e 70 pacientes sem doença respiratória (grupo-controle), com a idade variando entre 19 e 69 anos, apresentando média de 41,3, desvio-padrão 13,6 anos. Os parâmetros clínicos para avaliar as alterações periodontais foram obtidos por meio da profundidade de bolsa, do sangramento a sondagem, do índice de placa e da perda de inserção clínica. Resultados: Ambos os grupos não apresentaram diferença significativa em nenhuma das variáveis de controle (p>0,05). Os grupos apresentaram diferença significativa apenas no índice de placa (p<0,05) sendo média de 0,36, desvio-padrão de 0,30 nos controles e nos casos média de 0,51, desvio-padrão 0,35. Conclusão: A doença periodontal não apresentou associação significativa com a doença pulmonar, tanto em gravidade quanto na extensão (p>0,05). Devido ao aumento do índice de placa bacteriana na cavidade bucal de pacientes com doenças respiratórias, novos estudos devem ser realizados para verificar qual a relação entre as duas doenças.

Objective: To verify the association between periodontal disease and lung disease from an epidemiological, case and control survey, in patients who attended the first aid service of the Adriano Jorge Foundation Hospital, Manaus, Amazonas, Brazil, from June 2006 to February 2007. Methods: The sample consisted of 140 patients, among whom community-acquired pneumonia was present in 60% (n = 70), and chronic obstructive pulmonary disease in 40% (case-group); and 70 patients without respiratory disease (control group), ranging between 19 and 69 years of ages, with a mean age of 41.3, and standard deviation of 13.6 years. The clinical parameters for evaluating periodontal changes were obtained by means of pocket depth, bleeding on probing, plaque index and clinical attachment loss. Results: Both groups showed no significant difference in any of the control variables (p>0.05). The groups showed significant difference only in the plaque index (p <0.05) and the mean was 0.36, standard deviation 0.30 in control group, and in the cases a mean of 0.51, standard deviation 0.35. Conclusion: Periodontal disease showed no significant association with lung disease, both in severity and extension (p> 0.05). Due to the increase in the bacterial plaque index in the oral cavity of patients with respiratory diseases, further studies should be conducted to verify what the relationship between the two diseases is.