In Vivo Evaluation of Permeable and Impermeable Membranes for Guided Bone Regeneration.

BACKGROUND: The degree of biodegradation and the inflammatory response of membranes employed for guided bone regeneration directly impact the outcome of this technique. This study aimed to evaluate four different experimental versions of Poly (L-lactate-co-Trimethylene Carbonate) (PTMC) + Poly (L-lactate-co-glycolate) (PLGA) membranes, implanted in mouse subcutaneous tissue, compared to a commercially available membrane and a Sham group. METHODS: Sixty Balb-C mice were randomly divided into six experimental groups and subdivided into 1, 3, 6 and 12 weeks (n = 5 groups/period). The membranes (1 cm2) were implanted in the subcutaneous back tissue of the animals. The samples were obtained for descriptive and semiquantitative histological evaluation (ISO 10993-6). RESULTS: G1 and G4 allowed tissue adhesion and the permeation of inflammatory cells over time and showed greater phagocytic activity and permeability. G2 and G3 detached from the tissue in one and three weeks; however, in the more extended periods, they presented a rectilinear and homogeneous aspect and were not absorbed. G2 had a major inflammatory reaction. G5 was almost completely absorbed after 12 weeks. CONCLUSIONS: The membranes are considered biocompatible. G5 showed a higher degree of biosorption, followed by G1 and G4. G2 and G3 are considered non-absorbable in the studied periods.

Analysis of the Viability and Morphology of Gingival Cells on Materials Used in Novel Prosthetic Components: In Vitro Study.

AIM: The objective of this in vitro study was to evaluate the viability and morphology of human fibroblasts and keratinocytes cells, both grown on stainless steel (steel) (18Cr14Ni2.5Mo), and polyether-ether-ketone (PEEK) surfaces, hypothesizing the use of these surfaces as novel materials for prosthetic components. MATERIALS AND METHODS: Gingival human keratinocytes and gingival human fibroblasts lines were grown on discs made by steel (n = 36), PEEK (n = 36), and titanium (Ti) (Ti6A14V) (n = 36)-control. For viability assay, cultures were grown at 24 hours (TV1), 48 hours (TV2), and 72 hours (TV3) times and evaluated by the colorimetric tetrazolium assay (MTT). For morphology and cell adhesion assays, after 24 hours (TM1), 48 hours (TM2), and 96 hours (TM3) of cell culture, cells were examined by scanning electron microscopy (SEM) and analyzed at magnifications with 500×, 1,000×, and 2,500×. RESULTS: Regarding the viability, the keratinocytes did not present statistical difference on the different materials, in TV1 and TV3 times of culture. Their growth rate increased on all materials, being more expressive in steel; the fibroblasts did not present statistical difference on the different materials, in TV2 and TV3 times of culture. The growth rate of these decreased on all materials, being more expressive in PEEK. The morphology analyses show increase in cell numbers, adequate spreading, and adhesion at all cultivation times (TM1, TM2, and TM3) in both cell lines, on all materials. CONCLUSION: All materials tested are suitable for use in the manufacture of prosthetic components for implant-supported rehabilitations, considering the limitations of this study. CLINICAL SIGNIFICANCE: This work analyzes the cellular response of cells present in the human gingiva, as a way to simulate the peri-implant tissue response around novel angular prosthetic components made of stainless steel and PEEK.

Avaliação funcional do desenho de três brocas de preparo para colocação do implante dentário / Functional evaluation of three different drill designs for dental implant osteotomy: an in vitro study

Objetivos: avaliar o desempenho de furação de brocas. Material e métodos: três sistemas de implantes brasileiros foram testados: A (FGM, Joinville); B (Neodent, Curitiba); e C (SIN, São Paulo). A força de furação foi mantida constante e igual a 35 N. A rotação das brocas foi de 800 rpm e os corpos-de-prova foram mantidos em temperatura de 36°C ± 2°C, sendo a água destilada como fluido refrigerante. Dados sobre a temperatura e torque de furação foram adquiridos, e o desgaste das brocas foi avaliado por MEV. Os testes Anova e Tukey (α=5%) foram utilizados na análise estatística. Resultados: as brocas são eficazes, não ultrapassando a temperatura de limite biológico (47°C). Conclusão: de acordo com os ensaios realizados, a broca do grupo A reúne características que a habilitam como broca de perfuração única no preparo do leito do implante dentário. A análise em MEV mostrou que os grupos A e B mantiveram os gumes de corte bem defi nidos e sem desgaste aparente.

Objectives: to evaluate the osteotomy performance of implant drills. Material and methods: three different Brazilian dental implant systems were tested: A (FGM, Joinville), B (Neodent, Curitiba), and C (SIN, São Paulo). Drilling force was kept at 35 N. Drill rotation was set at 800 RPM and samples were kept at 36 ± 2°C under water coolant. Data regarding temperature and torque were acquired and drill wear evaluated under SEM. The Anova and Tukey tests (α=5%) were applied for statistical analyses. Results: all drills were effi cient and remained below the biologic limit level (47°C). Conclusion: according to the tests, drills of the A group had characteristics for a single osteotomy at the bone bed for implant placement. The SEM analysis demonstrated that groups A and B still had sharp, well-defi ned cutting edges with no visible wear.

Levantamento de seio maxilar com osso particulado de torus mandibular – relato de caso com análise histológica / Maxillary sinus lifting using particulate bone from mandibular torus – case report with histological analysis

O presente artigo apresenta a utilização de osso autógeno, removido do torus mandibular, em levantamento do seio maxilar com a finalidade de reabilitação oral com implante osseointegrado. Um paciente de 40 anos de idade, do sexo masculino, foi apresentado com falta do dente 16 e torus mandibular bilateral, com queixas de dificuldade fonética e de deglutição. No exame clínico foi detectado torus mandibular multilobulado bilateral de grandes proporções e o paciente relatou crescimento lento, porém, contínuo, nas últimas duas décadas. Em exame radiográfico panorâmico foi constatada a necessidade de reconstrução óssea por levantamento do seio maxilar direito, para permitir a instalação de implante e posterior reabilitação. O torus mandibular do paciente foi então removido, particulado e utilizado para o enxerto ósseo no antro maxilar. Foi realizada análise histológica das amostras, tanto do tecido ósseo como do tecido de revestimento, no momento da remoção do torus. Outra análise histológica foi realizada na área enxertada após um período de 120 dias. Constatou-se nas lâminas obtidas que o enxerto foi devidamente remodelado e estimulou novo crescimento ósseo na área do seio maxilar, permitindo assim a adequada osseointegração do implante e a devida reabilitação protética da área em questão...

This article presents the use of autogenous, particulate bone graft from mandibular tori for maxillary sinus lifting and implant-supported oral rehabilitation. A 40 years-old male patient with the lack of tooth 16 had complaints of phonetics and swallowing. The clinical exam revealed large bilateral mandibular torus, being of slow and continuous in the last two decades. The panoramic radiograph demonstrated the need for sinus elevation at the right side before implant placement. The tori were removed, particulate, and inserted at the recipient site. Histological analysis of the soft and hard tissues of the tori was performed. Another microscopic examination was performed 120 days later at the grafted area. It was concluded that the graft has remodeled and stimulated new bone formation at the maxillary sinus, which allows for implant osseointegration and prosthetic rehabilitation...