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1.
Clin Oral Investig ; 26(3): 2693-2701, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34694495

RESUMO

OBJECTIVES: This study evaluated the effect of embedding simvastatin (SIM) on the osteoinductive capacity of PLGA + HA/ßTCP scaffolds in stem cells from human exfoliated deciduous teeth (SHED). MATERIALS AND METHODS: Scaffolds were produced by PLGA solvent dissolution, addition of HA/ßTCP, solvent evaporation, and leaching of sucrose particles to impart porosity. Biphasic ceramic particles (70% HA/30% ßTCP) were added to the PLGA in a 1:1 (w:w) ratio. Scaffolds with SIM received 1% (w:w) of this medication. Scaffolds were synthesized in a disc-shape and sterilized by ethylene oxide. The experimental groups were (G1) PLGA + HA/ßTCP and (G2) PLGA + HA/ßTCP + SIM in non-osteogenic culture medium, while (G3) SHED and (G4) MC3T3-E1 in osteogenic culture medium were the positive control groups. The release profile of SIM from scaffolds was evaluated. DNA quantification assay, alkaline phosphatase activity, osteocalcin and osteonectin proteins, extracellular calcium detection, von Kossa staining, and X-ray microtomography were performed to assess the capacity of scaffolds to induce the osteogenic differentiation of SHED. RESULTS: The release profile of SIM followed a non-liner sustained-release rate, reaching about 40% of drug release at day 28. Additionally, G2 promoted the highest osteogenic differentiation of SHED, even when compared to the positive control groups. CONCLUSIONS: In summary, the osteoinductive capacity of poly(lactic-co-glycolic) acid and biphasic ceramic scaffolds was expressively enhanced by embedding simvastatin. CLINICAL RELEVANCE: Bone regeneration is still a limiting factor in the success of several approaches to oral and maxillofacial surgeries, though tissue engineering using mesenchymal stem cells, scaffolds, and osteoinductive mediators might collaborate to this topic.


Assuntos
Osteogênese , Sinvastatina , Diferenciação Celular , Cerâmica/farmacologia , Glicóis/farmacologia , Humanos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/farmacologia , Sinvastatina/farmacologia , Engenharia Tecidual , Alicerces Teciduais
2.
Clin Adv Periodontics ; 11(4): 213-219, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-32852884

RESUMO

INTRODUCTION: Defects in the maxillary anterior teeth are delicate and difficult to solve because of the esthetic, functional, and psychological impairment that may arise if the rehabilitation treatment does not return the damaged tissues to the naturalness. Esthetic predictability and reduced surgical interventions are some great reasons to simplify dental treatments. During the presurgical evaluation, the clinician should review the implant esthetic risk profile, considering the patient's smile line, the esthetic demands, the hard and soft tissue thickness and width, and the gingival biotype. Thus, achieving long-term esthetic results initiates with a detailed case planning before surgical intervention. CASE PRESENTATION: The present report described a complex esthetic clinical case involving teeth and dental implant related to a high smile line. The clinical case was solved through immediate implant placement and immediate loading using a personalized prosthetic abutment and finalized with the installation of metal-free prosthetic restorations. CONCLUSION: The use of a personalized prosthetic abutment helped to achieve a better emergence of the prosthesis under the periodontal tissues. Although it was a challenging esthetic case, especially because of the high smile line, the result was a natural smile while the adjacent soft tissues maintained their esthetics and health.


Assuntos
Estética Dentária , Gengiva , Humanos
3.
Clin Oral Investig ; 25(6): 3441-3451, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33155065

RESUMO

OBJECTIVES: The aim of the present study was to investigate whether peri-implant clinical parameters (modified plaque index (mPI), bleeding and/or suppuration on probing (B/SOP)) and local factors (type of prostheses, screw emergence, platform diameter, and abutment angulation) might contribute to the development of additional bone loss and peri-implantitis around dental implants. MATERIALS AND METHODS: Two hundred seventy-seven external hex connection implants placed in the posterior maxilla of 124 patients were retrospectively evaluated. They were divided into two groups: physiologic bone loss < 2 mm (PBL) or additional bone loss ≥ 2 mm (ABL). GEE logistic regression was applied to evaluate the influence of type of prostheses (implant-supported single crown (ISSC), fixed partial denture (ISFPD), and full denture (ISFD)) and clinical parameters (mPI and S/BOP) on bone loss. RESULTS: Among the 277 implants, 159 (57.4%) presented PBL and 118 (42.6%) presented ABL. Within the ABL group, 20.6% implants were diagnosed with peri-implantitis. mPI significantly correlated with the type of prosthesis and the highest value of mPI (index = 3) was observed in ISFD (23.8%). Moreover, peri-implantitis was more frequently associated with ISFD (32.79%) than ISSC and ISFDP (13.79% and 13.48, respectively) CONCLUSIONS: ISFD in the posterior maxilla presented high rates of ABL and showed a higher prevalence of peri-implantitis. None of the local factors seemed to contribute to the development of these conditions. Further investigations are needed to prospectively support the results of the present study. CLINICAL RELEVANCE: Patients rehabilitated with ISFD should be carefully monitored and have more frequent maintenance visits to prevent or control peri-implant bone loss.


Assuntos
Perda do Osso Alveolar , Implantes Dentários , Peri-Implantite , Perda do Osso Alveolar/diagnóstico por imagem , Implantes Dentários/efeitos adversos , Prótese Dentária Fixada por Implante , Humanos , Maxila/diagnóstico por imagem , Maxila/cirurgia , Análise Multivariada , Peri-Implantite/diagnóstico por imagem , Estudos Retrospectivos
4.
J Periodontal Res ; 55(1): 116-124, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31493346

RESUMO

OBJECTIVE: To propose a biofunctionalized prosthetic abutment by analyzing physico-chemical and morphological properties, simvastatin (SIM) release, and biocompatibility of titanium (Ti) disks coated with poly(lactic-co-glycolic) acid (PLGA) incorporating SIM. METHODS: Titanium disks (8 × 3 mm) were distributed into four groups: Ti: pure Ti; Ti + PLGA: Ti coated with PLGA; Ti + PLGA + SIM6%: Ti + PLGA with 6% SIM; and Ti + PLGA + SIM0.6%: Ti + PLGA incorporating 0.6% SIM. PLGA was prepared through chloroform evaporation technique. After complete dissolution of PLGA, SIM was diluted in the solution. Ti + PLGA, Ti + PLGA + SIM6%, and Ti + PLGA + SIM0.6% were dip coated with PLGA and PLGA + SIM, respectively. Samples were sterilized by ethylene oxide. For SIM release assay, disks were submerged in PBS, pH 7.4, 37°C, 30 rpm up to 600 hours. At different time intervals, SIM was quantified by spectrophotometry (238 nm). For characterization of the biomaterial components, it was performed Fourier-transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy (SEM), optical profilometry, and atomic force microscopy. Biocompatibility analyses were performed by MTS colorimetric assay on murine fibroblasts L929, human gingival fibroblasts (HGFs), and stem cells from human exfoliated deciduous teeth (SHEDs). Absorbance was measured at 490 nm, and percentages of viable cells were calculated in relation to positive control (Ti). SEM images were obtained to verify cell adhesion and morphology. One-way ANOVA followed by Tukey's post hoc test was applied (P < 0.05) for statistical analyses. RESULTS: SIM release was slow and continuous, reaching about 21% of the incorporated SIM after 600 hours. Topographical analyses revealed success in coating Ti disks with PLGA incorporating SIM. Regarding biocompatibility test, Ti + PLGA + SIM0.6% showed the highest percentage of L929 viability at days 3 and 7. There was no significant difference for Ti, Ti + PLGA, and Ti + PLGA + SIM0.6% groups on cell viability of both SHEDs and HGFs at days 3 and 7. SEM corroborates that SHEDs and HGFs were able to adhere and proliferate on Ti, Ti + PLGA, and Ti + PLGA + SIM0.6% surfaces. CONCLUSION: A slow and controlled release of SIM was achieved, attributed to a diffusional mass transfer mechanism. Moreover, a homogenous coating topography was obtained. Additionally, 0.6% SIM incorporated into PLGA coating improved fibroblasts L929 viability compared to titanium or PLGA. Also, 0.6% SIM incorporated into PLGA promoted cell viability of about 100% for HGFs and approximately 150% for human mesenchymal stem cells. Therefore, this study allows to consider the use of PLGA-coated titanium incorporating SIM as a biofunctionalized abutment for dental implants.


Assuntos
Dente Suporte , Planejamento de Prótese Dentária , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Sinvastatina , Titânio , Animais , Materiais Biocompatíveis , Linhagem Celular , Humanos , Camundongos , Microscopia Eletrônica de Varredura , Propriedades de Superfície
5.
J Clin Periodontol ; 47(1): 120-128, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31628873

RESUMO

AIM: Our objective was to compare guided virtual surgery to conventional surgery in terms of angular deviation of single dental implants placed in the posterior mandible. MATERIALS AND METHODS: Patients with bilateral homologous single teeth missing in the posterior mandible were eligible for this split-mouth randomized clinical trial. Cone beam computed tomography (CBCT) was performed for virtual planning of implant position and manufacturing of the stereolithographic guides. One week after the surgery, a second CBCT scan was superimposed to the initial planning. Primary endpoint was the angular deviation between virtual and clinical implant position. Secondary endpoints were linear deviations and patient-reported outcomes collected with a questionnaire. RESULTS: Data from 12 patients were available for analysis. Angular deviation was significantly lower using stereolithographic guides as compared to conventional guides (2.2 ± 1.1° vs. 3.5 ± 1.6°, p = .042). Linear deviations were similar for both techniques in the coronal (2.34 ± 1.01 vs. 1.93 ± 0.95 mm) and apical (2.53 ± 1.11 vs. 2.19 ± 1.00 mm) dimensions (p Ëƒ .05). The selection of the surgical technique had no significant impact on the patient-reported outcomes. CONCLUSION: Our data suggest that the angular discrepancy between the virtual and the clinical implant position is slightly lower when using stereolithographic guides as compared to conventional guides.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endóssea , Humanos , Imageamento Tridimensional , Boca , Planejamento de Assistência ao Paciente
6.
J Biomed Mater Res B Appl Biomater ; 107(6): 2152-2164, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30653823

RESUMO

The aim of this study was to evaluate the release of simvastatin from scaffolds composed of poly(lactic-co-glycolic) acid (PLGA) and biphasic ceramic designed for bone engineering and to assess the physico-chemical and mechanical properties of the scaffolds. Samples with 30% and 70% porosity were obtained with 0, 2, 5, and 8 wt %. of simvastatin through the solvent evaporation technique and leaching of sucrose particles. Scaffold degradation and simvastatin release were evaluated in phosphate-buffered saline. Scaffolds were analyzed by scanning electron microscopy and microtomography for two-dimensional and three-dimensional morphological characterization of the porosity, connectivity, and intrinsic permeability. The mechanical characterization was conducted based on the compressive strength and the chemical characterization by differential scanning calorimetry and energy dispersive X-ray spectroscopy. Gradual and prolonged simvastatin release from the scaffolds was observed. The release followed the Korsmeyer kinetics model with the predominance of case II transport for 30% porosity scaffolds, and anomalous behavior for the 70% porosity samples. Simvastatin release was also influenced by the slow scaffold degradation due to the strong chemical interaction between simvastatin and PLGA, as observed by differential scanning calorimetry. The scaffolds presented spherical and sucrose crystal-shaped pores that resulted in a homogenous porosity, with a predominance of open pores, ensuring interconnectivity. Simvastatin incorporation into the scaffolds and increased porosity did not influence the mechanical properties. The scaffolds presented gradual and prolonged simvastatin release, with satisfactory physico-chemical and mechanical properties. The scaffolds presented gradual and prolonged simvastatin release, with satisfactory physico-chemical and mechanical properties, a promise for applications in bone regeneration. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2152-2164, 2019.


Assuntos
Regeneração Óssea , Cerâmica/química , Hidroxiapatitas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , Sinvastatina , Animais , Implantes de Medicamento/química , Implantes de Medicamento/farmacocinética , Humanos , Sinvastatina/química , Sinvastatina/farmacocinética
7.
J Periodontal Res ; 54(1): 46-52, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30368813

RESUMO

OBJECTIVE: The aim of this study was to evaluate surface changes on dental implant systems and ions release after immersion in fluoride and hydrogen peroxide. METHODS: Ten implant-abutment assemblies were embedded in acrylic resin and cross-sectioned along the implant vertical axis. Samples were wet ground and polished. Delimited areas of groups of samples were immersed in 1.23% sodium fluoride gel (F) or in 35% hydrogen peroxide (HP) for 16 min. Gels (n = 3) were collected from the implant surfaces and analyzed by inductively coupled plasma mass spectrometry (ICP-MS), to detect the concentration of metallic ions released from the implant systems. Selected areas of the abutment and implant (n = 15) were analyzed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). RESULTS: SEM images revealed surface topographic changes on implant-abutment joints after immersion in fluoride. Implants showed excessive oxidation within loss of material, while abutment surfaces revealed intergranular corrosion after immersion in fluoride. ICP-MS results revealed a high concentration of Ti, Al, V ions in fluoride after contact with the implant systems. Localized corrosion of implant systems could not be detected by SEM after immersion in hydrogen peroxide although the profilometry showed increase in roughness. ICP-MS showed the release of metallic ions in hydrogen peroxide medium after contact with dental implants. CONCLUSION: Therapeutical substances such as fluorides and hydrogen peroxide can promote the degradation of titanium-based dental implant and abutments leading to the release of toxic ions.


Assuntos
Projeto do Implante Dentário-Pivô , Implantes Dentários , Peróxido de Hidrogênio/efeitos adversos , Imersão/efeitos adversos , Fluoreto de Sódio/efeitos adversos , Corrosão , Géis , Íons , Espectrometria de Massas , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Oxirredução , Propriedades de Superfície , Fatores de Tempo , Titânio
8.
J Biomed Mater Res A ; 106(6): 1614-1625, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29377525

RESUMO

The aim of this study was to evaluate the chemical reactivity of 58S mesoporous bioactive glass (MBG) particles in as-synthesized condition and after embedding propolis and cranberry antibiofilm compounds at different concentrations. MBG 58S was synthesized by alkali sol-gel method with the addition of the triblock pluronic copolymer P123 as surfactant. Samples were characterized by physicochemical properties measurement, N2 adsorption/desorption analysis, and field emission gun scanning electron microscopy (FEGSEM) observations. MBG powders were immersed into 5 and 10 µg/mL propolis or cranberry solutions for 24 h. The chemical reactivity of the specimens was evaluated by FEGSEM, EDX, FTIR, Ca/P ratio, XRD, and sample weight gain analysis after being immersed in simulated body fluid (SBF) for 8, 24, and 72 h. MBG particles exhibited the expected chemical composition with a particle size distribution ranging from 1.44 to 955 µm, and a mean particle size of 154 µm. MBG particles exhibited a pore volume of 0.8 cc/g, pore radius of ∼2 nm, and surface area of 350.2 m2 /g, according to BJH and BET analyses. A hydroxyl-carbonate apatite (HCAp) layer was formed on all samples after SBF immersion for 72 h. Pure MBG showed the highest chemical reactivity after 72 h, with the resulting apatite layer exhibiting a Ca/P ratio of ∼1.6 in accordance to stoichiometric biological apatite. MBG embedding propolis and cranberry can be considered for future microbiological analysis since the presence of propolis or cranberry did not interfere with MBG's ability to develop a HCAp layer, which is an essential feature for bone regeneration applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1614-1625, 2018.


Assuntos
Anti-Infecciosos/administração & dosagem , Substitutos Ósseos/química , Vidro/química , Extratos Vegetais/administração & dosagem , Própole/administração & dosagem , Apatitas/química , Humanos , Transição de Fase , Poloxaleno/química , Porosidade , Tensoativos/química , Vaccinium macrocarpon/química
9.
Eur J Dent ; 11(4): 496-502, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29279677

RESUMO

OBJECTIVES: After tooth loss, dimensional alterations on the alveolar bone ridge can occur that can negatively affect the placement of dental implants. The purpose of this study was to evaluate the synthesis, and mechanical properties of ß-tricalcium phosphate (ß-TCP) scaffolds coated with bioabsorbable polymers, namely, collagen and poly (D, L-lactic acid) (PDLLA). MATERIALS AND METHODS: ß-TCP powder was obtained by reactive milling and then characterized by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). ß-TCP scaffolds were obtained by replica method, in which polyurethane foams are immersed in ß-TCP suspension and thereafter submitted to a thermal treatment to remove the polyurethane and sinter the ceramic. Type-I collagen or PDLLA were used to coat the ß-TCP scaffolds by dip-coating method. Scaffolds were separated in four groups depending on the coating material: noncoated (Group A), double immersion in collagen (Group B), double immersion in PDLLA (Group C), and ten immersions in PDLLA (Group D). Samples were characterized by compressive tests and SEM/EDS. Data were statistically analyzed through two-way ANOVA (p = 0.05). RESULTS: Chemical and microscopic analyses revealed proper morphology and chemical composition of powder particles and scaffolds with or without polymeric coatings. Scaffolds coated with PDLLA showed higher compressive strength (0.11 ± 0.054 MPa) than those of collagen (0.022 ± 0.012 MPa) or noncoated groups (0.024 ± 0.012 MPa). CONCLUSIONS: The coating method of ß-TCP with PDLLA revealed a potential strategy to increase the mechanical strength of porous ceramic materials while collagen can enhance cell migration.

10.
Eur J Dent ; 11(4): 553-558, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29279686

RESUMO

The aim of this study was to perform an integrative review of the literature on the clinically usual prosthesis-abutment misfit over implant-supported structures manufactured by conventional casting technique. The present integrative review used the PRISMA methodology. A bibliographical search was conducted on the following electronic databases: MEDLINE/PubMed (National Library of Medicine), Scopus (Elsevier), ScienceDirect (Elsevier), Web of Science (Thomson Reuters Scientific), Latin American and Caribbean Center on Health Sciences Information (BIREME), and Virtual Health Library (BVS). A total of 11 relevant studies were selected for qualitative analysis. The prosthetic-abutment vertical misfit considered clinically usual ranged from 50 to 160 µm. The vertical misfit depends on several steps during technical manufacturing techniques, which includes the materials and technical procedures. Lower values in misfit are recorded when precious metal or titanium alloys are utilized. Although a vertical misfit mean value of 100 µm has been considered clinically usual, most of the previous studies included in this revision showed lower mean values.

11.
Mater Sci Eng C Mater Biol Appl ; 70(Pt 1): 456-460, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27770916

RESUMO

Poly(ether-ether-ketone) (PEEK) has also shown to be very attractive for incorporating therapeutic compounds thanks to a sulfonation process which modifies the material structure resulting in a sulfonated-PEEK (sPEEK). Concerning biomedical applications, the objective of this work was to evaluate the influence of different sulfonation degree of sPEEK on the biofilm growth. PEEK samples were functionalized by using sulphuric acid (98%) and then dissolved into dimethyl-sulfoxide. A dip coating technique was used to synthesize sPEEK thin films. The sulfonation degree of the materials was analyzed by FT-IR, H NMR, TG and IEC. The surfaces were characterized by scanning electron microscopy, profilometry and contact angle analyses. Subsequently, the biofilm formation on sulfonated-PEEK based on Streptococcus mutans and Enterococcus faecalis was measured by spectrophotometry, colony forming units (CFUmL-1) and SEM. Results obtained from thermal and chemical analyses showed an intensification in sulfonation degree for sPEEK at 2 and 2.5h. The E. faecalis or S. mutans biofilm growth revealed statistically significant differences (p<0.05) between 2 and 3h sulfonation groups. A significant decrease (p<0.05) in CFUmL-1 was recorded for S. mutans or E. faecalis biofilm grown on 2.5 or 3h sPEEK. Regarding the thermal-chemical and microbiologic analyses, the sulfonation degree of sPEEK ranging from 2 up to 3h was successful capable to decrease the biofilm growth. That revealed an alternative strategy to embed anti-biofilm and therapeutic compounds into PEEK avoiding infections in biomedical applications.


Assuntos
Biofilmes/efeitos dos fármacos , Cetonas/farmacologia , Polietilenoglicóis/farmacologia , Ácidos Sulfônicos/farmacologia , Benzofenonas , Enterococcus faecalis/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Plâncton/efeitos dos fármacos , Plâncton/crescimento & desenvolvimento , Polímeros , Espectroscopia de Infravermelho com Transformada de Fourier , Streptococcus mutans/efeitos dos fármacos , Termogravimetria
12.
J Biomed Mater Res A ; 104(12): 3015-3020, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27458927

RESUMO

Poly-ether-ether-ketone (PEEK) is currently introduced as an alternative material for orthopedic implants due to its biocompatibility and low elastic modulus compared to titanium. Also, a sulphonation treatment can functionalize PEEK to embed therapeutical substances. The objective of this work was to functionalize a PEEK film to incorporate novel lactam-based antibiofilms compounds. PEEK samples were functionalized by sulphuric acid treatment and then dissolved in dimethylsulfoxide, where lactams were added to be incorporated into the polymer. A dip-coating technique was used to synthesize a thin film on a glass-based substrate. The degree of sulfonation (DS) and the incorporation of lactams into sulphonated PEEK (sPEEK) were analyzed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, thermogravimetric analysis (TGA), and scanning electron microscopy. A DS of 65% was obtained and TGA curves confirmed the presence of SO3 H and lactams in the sPEEK structure. The growth of Streptococcus mutans biofilm decreased on sPEEK surface containing lactams when compared to sPEEK free of lactams. That indicated the antibiofilm activity of those compounds was maintained after incorporation into sPEEK. Planktonic growth analysis showed no long distant effects of sPEEK containing lactams, indicating that no systemic effects should be expected upon clinical uses of medical devices produced with lactam-treated sPEEK. Results revealed that inclusion of lactams into sPEEK represents a good alternative for the production of biomaterials resistant to bacterial accumulation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 3015-3020, 2016.


Assuntos
Antibacterianos/farmacologia , Materiais Biocompatíveis/farmacologia , Biofilmes/efeitos dos fármacos , Cetonas/farmacologia , Lactamas/farmacologia , Polietilenoglicóis/farmacologia , Streptococcus mutans/efeitos dos fármacos , Antibacterianos/química , Benzofenonas , Materiais Biocompatíveis/química , Humanos , Cetonas/química , Lactamas/química , Polietilenoglicóis/química , Polímeros , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/fisiologia , Propriedades de Superfície
13.
Braz Dent J ; 27(2): 141-7, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27058375

RESUMO

The aim of this study was to evaluate the density and the morphological aspects of biofilms adhered to different materials applied in oral rehabilitation supported by dental implants. Sixty samples were divided into four groups: feldspar-based porcelain, CoCr alloy, commercially pure titanium grade IV and yttria-stabilized zirconia. Human saliva was diluted into BHI supplemented with sucrose to grow biofilms for 24 or 48 h. After this period, biofilm was removed by 1% protease treatment and then analyzed by spectrophotometry (absorbance), colony forming unit method (CFU.cm-2) and field-emission guns scanning electron microscopy (FEG-SEM). The highest values of absorbance and CFU.cm-2 were recorded on biofilms grown on CoCr alloys when compared to the other test materials for 24 or 48 h. Also, FEG-SEM images showed a high biofilm density on CoCr. There were no significant differences in absorbance and CFU.cm-2 between biofilms grown on zirconia, porcelain and titanium (p<0.05). Microbiological assays associated with microscopic analyses detected a higher accumulation of oral biofilms on CoCr-based materials than that on titanium or zirconia that are used for prosthetic structures.


Assuntos
Implantes Dentários , Materiais Dentários , Biofilmes , Humanos , Microscopia Eletrônica de Varredura , Saliva , Análise Espectral/métodos , Propriedades de Superfície
14.
Braz. dent. j ; Braz. dent. j;27(2): 141-147, Mar.-Apr. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-778330

RESUMO

Abstract The aim of this study was to evaluate the density and the morphological aspects of biofilms adhered to different materials applied in oral rehabilitation supported by dental implants. Sixty samples were divided into four groups: feldspar-based porcelain, CoCr alloy, commercially pure titanium grade IV and yttria-stabilized zirconia. Human saliva was diluted into BHI supplemented with sucrose to grow biofilms for 24 or 48 h. After this period, biofilm was removed by 1% protease treatment and then analyzed by spectrophotometry (absorbance), colony forming unit method (CFU.cm-2) and field-emission guns scanning electron microscopy (FEG-SEM). The highest values of absorbance and CFU.cm-2 were recorded on biofilms grown on CoCr alloys when compared to the other test materials for 24 or 48 h. Also, FEG-SEM images showed a high biofilm density on CoCr. There were no significant differences in absorbance and CFU.cm-2 between biofilms grown on zirconia, porcelain and titanium (p<0.05). Microbiological assays associated with microscopic analyses detected a higher accumulation of oral biofilms on CoCr-based materials than that on titanium or zirconia that are used for prosthetic structures.


Resumo O objetivo deste estudo foi avaliar a densidade e os aspectos morfológicos dos biofilmes aderidos a diferentes materiais aplicados em reabilitação oral sobre implantes dentários. Sessenta amostras foram divididas em quatro grupos: porcelana à base de feldspato, liga de CoCr, titânio grau IV comercialmente puro e zircônia estabilizada com ítrio. Saliva humana diluída em BHI foi suplementada com sacarose para possibilitar a formação de biofilme por 24 e 48 h. Após este período, o biofilme foi removido utilizando protease a 1% e, em seguida, analisada por espectrofotometria (absorbância), unidades formadoras de colônia (CFU.cm-2) e microscopia eletrônica de varredura (MEV). Os valores mais elevados de absorbância e CFU.cm-2 foram encontrados em ligas de CoCr quando comparado com os outros materiais testados. Os resultados obtidos foram semelhantes nos biofilmes formados sobre titânio e zircônia durante 24 e 48 h (p<0,05). As análises microbiológicas e microscópicas demostraram uma maior tendência ao acúmulo de biofilmes orais sobre estruturas protéticas baseadas em CoCr quando comparadas com porcelana feldspática, titânio ou zircônia.


Assuntos
Humanos , Implantes Dentários , Materiais Dentários , Biofilmes , Microscopia Eletrônica de Varredura , Saliva , Análise Espectral/métodos , Propriedades de Superfície
15.
Artigo em Inglês | MEDLINE | ID: mdl-23058228

RESUMO

The objective of this study was to evaluate the use of a unique resorbable bovine bone screw to stimulate bone formation. Bovine bone screws were inserted in the tibia of beagle dogs. Each animal received 8 screws, divided into groups A (screws + no membranes), B (screws + titanium reinforced membranes), and C (bone defects treated with autogenous bone grafts). Animals were killed at 2, 4, and 6 months. New bone was measured with a periodontal probe and reported an average of 7.4 mm in vertical bone gain for group B, 3.6 mm for group A, and 1.7 mm for group C. Submission to Kruskal-Wallis test showed statistical differences among groups (P < .05). Histologic examination revealed an intimate contact between the newly formed bone and the resorbing bone screws. We conclude that bovine bone screws provide an environment for new bone formation and thus may provide an alternative therapy for enhancing bone formation vertically, including for regenerative procedures as well as before implant therapy.


Assuntos
Regeneração Óssea/fisiologia , Parafusos Ósseos , Transplante Ósseo/métodos , Osseointegração/fisiologia , Osteogênese/fisiologia , Animais , Materiais Biocompatíveis , Transplante Ósseo/instrumentação , Bovinos , Cães , Feminino , Técnicas Histológicas , Tíbia
16.
Acta Odontol Latinoam ; 24(1): 21-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22010402

RESUMO

The aim of this study was to evaluate the fit between dental abutments and the metal framework of a 3-unit fixed prosthesis screwed to two implants to determine whether sectioning and soldering of the framework are in fact necessary procedures. The study was based on a model of a metal framework of a 3-unit prosthesis screwed to two implants. A total of 18 metal frameworks were constructed and divided into 3 groups: (1) NS group - each framework was cast in one piece and not sectioned; (2) CS group - the components of each sectioned framework were joined by conventional soldering; and (3) LW group - the components of each sectioned framework were joined by laser welding. The control group consisted of six silver-palladium alloy copings that were not cast together. Two analyses were mperformed: in the first analysis, the framework was screwed only to the first abutment, and in the second analysis, the framework was screwed to both abutments. The prosthetic fit was assessed at a single point using a measuring microscope (Measurescope, Nikon, Japan) and the marginal gap was measured in micrometers. Statistical analysis was performed using analysis of variance (ANOVA), Scheffe's test, Student's t-test, and Mann-Whitney U test. The NS group had larger marginal gaps than the other groups (p<0.01), while the CS and LW groups had a similar degree of misfit with no significant difference between them. The results revealed that, in the case of short-span 3-unit fixed prostheses, the framework should be sectioned and soldered or welded to prevent or reduce marginal gaps between the metal framework and dental abutments.


Assuntos
Prótese Dentária Fixada por Implante/métodos , Soldagem em Odontologia
17.
Acta Odontol Latinoam ; 20(2): 87-95, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18590257

RESUMO

The aim of the present study was to clinically and radiographically assess the peri-implant and periodontal conditions in partially edentulous patients with implant-supported fixtures installed, at least, one year prior to the study. 41 patients were examined by a calibrated examiner in relation to the following implant-associated parameters: Modified Plaque Index (mPlI), Modified Bleeding Index (mBI), probing depth (PD), clinical attachment level (CAL) and bleeding on probing of the bottom of the crevice (BOP). Also, the remaining teeth were assessed in terms of Plaque Index (PlI), Gingival Index (GI), PD, CAL and BOP. The peri-implant bone loss was evaluated by means of periapical radiographs. Measurements of pre-operatory and final bone levels allowed an estimation of bone loss associated to teeth and a comparison with bone loss around implants. None of the individuals presented late loss of implants until the examination took place. No statistically significant differences were observed between PlI (0.90+/-0.07) and mPlI (0.82+/-0.13), or between GI (0.11+/-0.02) and mBI (0.10+/-0.02). However, PD, CAL and BOP values were higher in implants than in teeth (Wald Test, p<0.01). Implants presented a mean annual bone loss during the study period of 0.77 mm (SE=0.06). Teeth virtually did not present any bone loss (mean value of 0.36%) whereas implants exhibited a bone loss value of 17.11%. Plaque accumulation and marginal inflammation did not differ between teeth and implants. However, subgingival inflammation was higher in implants than in teeth. The destruction measurements suggest greater losses in implants, as expected because of tissue remodelation.


Assuntos
Implantes Dentários , Prótese Dentária Fixada por Implante , Doenças Periodontais/classificação , Adulto , Idoso , Perda do Osso Alveolar/classificação , Perda do Osso Alveolar/diagnóstico por imagem , Índice de Placa Dentária , Feminino , Seguimentos , Hemorragia Gengival/classificação , Gengivite/classificação , Humanos , Arcada Parcialmente Edêntula/reabilitação , Arcada Parcialmente Edêntula/cirurgia , Masculino , Pessoa de Meia-Idade , Perda da Inserção Periodontal/classificação , Doenças Periodontais/diagnóstico por imagem , Bolsa Periodontal/classificação , Periodontite/classificação , Radiografia
19.
J Oral Implantol ; 30(5): 325-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15587024

RESUMO

This article describes a newly designed surgical template that was used to facilitate dental implant placement. The implants were planned to function by loading them immediately. A case report describing the device and the benefits of its use for a patient with an edentulous mandible is presented. Four implants were placed in the anterior region of the mandible to support an immediately fixed prosthesis. Clinical and radiographic analyses were conducted postoperatively to evaluate bone loss and peri-implant soft-tissue healing. The salutary results demonstrated the positive value of this therapeutic approach and presented the advantages of shorter treatment times, fewer patient visits, lower costs, and elimination of secondary surgical procedures.


Assuntos
Implantação Dentária Endóssea/instrumentação , Planejamento de Prótese Dentária/instrumentação , Arcada Edêntula/reabilitação , Implantes Dentários , Feminino , Humanos , Pessoa de Meia-Idade
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