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Martin Rosentritt - One of the best experts on this subject based on the ideXlab platform.

  • Bacterial adhesion of Streptococcus mutans to esthetic Bracket materials.
    American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists its constituent socie, 2008
    Co-Authors: Andreas Faltermeier, Ralf Bürgers, Martin Rosentritt
    Abstract:

    The formation of white spot lesions and enamel demineralization might be intensified by enhanced bacterial adhesion and formation of dental plaque on Brackets. Our aim in this in-vitro study was to investigate the susceptibility of various Plastic Bracket materials to the adherence of Streptococcus mutans. The esthetic Bracket raw materials included in this study were polyoxymethylene, polycarbonate, high-density polyethylene, and an experimental polymer (90% polyethylene). Surface roughness was assessed by perthometer. S mutans suspension was incubated with test specimens and examined with fluorescence dye and an automated multi-detection reader. The oxidation-reduction fluorescence dye Alamar Blue/resazurin (0.007536 g per 10 mL distilled water) was used to determine the quantity of bacterial adhesion. The median values of fluorescence intensity varied between approximately 600 and 1600. The lowest fluorescence with median values below 700, indicating low bacterial adhesion, was found for polyoxymethylene (median of relative fluorescence intensity, 635). The highest relative fluorescence intensity, with median values of more than 1500, was for high-density polyethylene (1565). No statistical alteration of fluorescence intensity was measured between the polymeric Bracket materials. The investigated polymeric Bracket materials had no significant differences in the quantities of S mutans adhering to them. Regardless of the polymer, Plastic Bracket materials have similar bacterial colonization and plaque accumulation properties.

  • Bacterial adhesion of Streptococcus mutans to esthetic Bracket materials
    American Journal of Orthodontics and Dentofacial Orthopedics, 2008
    Co-Authors: Andreas Faltermeier, Ralf Bürgers, Martin Rosentritt
    Abstract:

    Introduction The formation of white spot lesions and enamel demineralization might be intensified by enhanced bacterial adhesion and formation of dental plaque on Brackets. Our aim in this in-vitro study was to investigate the susceptibility of various Plastic Bracket materials to the adherence of Streptococcus mutans . Methods The esthetic Bracket raw materials included in this study were polyoxymethylene, polycarbonate, high-density polyethylene, and an experimental polymer (90% polyethylene). Surface roughness was assessed by perthometer. S mutans suspension was incubated with test specimens and examined with fluorescence dye and an automated multi-detection reader. The oxidation-reduction fluorescence dye Alamar Blue/resazurin (0.007536 g per 10 mL distilled water) was used to determine the quantity of bacterial adhesion. Results The median values of fluorescence intensity varied between approximately 600 and 1600. The lowest fluorescence with median values below 700, indicating low bacterial adhesion, was found for polyoxymethylene (median of relative fluorescence intensity, 635). The highest relative fluorescence intensity, with median values of more than 1500, was for high-density polyethylene (1565). No statistical alteration of fluorescence intensity was measured between the polymeric Bracket materials. Conclusions The investigated polymeric Bracket materials had no significant differences in the quantities of S mutans adhering to them. Regardless of the polymer, Plastic Bracket materials have similar bacterial colonization and plaque accumulation properties.

  • Influence of fibre and filler reinforcement of Plastic Brackets: an in vitro study
    The European Journal of Orthodontics, 2007
    Co-Authors: Andreas Faltermeier, Martin Rosentritt, Rupert Faltermeier, Dieter Müßig
    Abstract:

    In spite of their popularity in fulfilling aesthetic requirements, Plastic Brackets still present some disadvantages because of their low elastic modulus, decreased fracture toughness, and reduced wear resistance. Fibre-reinforced composites are well established in dentistry and consist of a polymer matrix in which reinforcing fibres are embedded. Stress is transferred from the polymer matrix to the fibres which present a high tensile strength. Hence, the mechanical properties of polymers could be improved. The purpose of this study was to compare fracture strength, fracture toughness and flexural strength of an experimental fibre-reinforced Bracket material, an SiO(2) filler-reinforced Bracket and an unfilled Plastic Bracket material (control group). Experimental Brackets and specialized bars were manufactured. Tests were performed after thermal cycling (5 degrees C/55 degrees C) the samples in an artificial oral environment of a device to simulate mastication. Statistical evaluation was undertaken. The median, 25th and 75th percentiles were calculated and a Mann-Whitney U-test was performed. In this study two findings were obvious. (1) Filler reinforcement of Plastic Brackets improved fracture strength and fracture toughness in comparison with the unfilled Bracket material. (2) Glass fibre reinforcement of orthodontic Bracket materials resulted in the greatest enhancement of the mechanical properties in comparison with the other test groups. Therefore, the application of glass fibres in Plastic Brackets is a successful method to enhance fracture strength.

Andreas Faltermeier - One of the best experts on this subject based on the ideXlab platform.

  • Bacterial adhesion of Streptococcus mutans to esthetic Bracket materials.
    American journal of orthodontics and dentofacial orthopedics : official publication of the American Association of Orthodontists its constituent socie, 2008
    Co-Authors: Andreas Faltermeier, Ralf Bürgers, Martin Rosentritt
    Abstract:

    The formation of white spot lesions and enamel demineralization might be intensified by enhanced bacterial adhesion and formation of dental plaque on Brackets. Our aim in this in-vitro study was to investigate the susceptibility of various Plastic Bracket materials to the adherence of Streptococcus mutans. The esthetic Bracket raw materials included in this study were polyoxymethylene, polycarbonate, high-density polyethylene, and an experimental polymer (90% polyethylene). Surface roughness was assessed by perthometer. S mutans suspension was incubated with test specimens and examined with fluorescence dye and an automated multi-detection reader. The oxidation-reduction fluorescence dye Alamar Blue/resazurin (0.007536 g per 10 mL distilled water) was used to determine the quantity of bacterial adhesion. The median values of fluorescence intensity varied between approximately 600 and 1600. The lowest fluorescence with median values below 700, indicating low bacterial adhesion, was found for polyoxymethylene (median of relative fluorescence intensity, 635). The highest relative fluorescence intensity, with median values of more than 1500, was for high-density polyethylene (1565). No statistical alteration of fluorescence intensity was measured between the polymeric Bracket materials. The investigated polymeric Bracket materials had no significant differences in the quantities of S mutans adhering to them. Regardless of the polymer, Plastic Bracket materials have similar bacterial colonization and plaque accumulation properties.

  • Bacterial adhesion of Streptococcus mutans to esthetic Bracket materials
    American Journal of Orthodontics and Dentofacial Orthopedics, 2008
    Co-Authors: Andreas Faltermeier, Ralf Bürgers, Martin Rosentritt
    Abstract:

    Introduction The formation of white spot lesions and enamel demineralization might be intensified by enhanced bacterial adhesion and formation of dental plaque on Brackets. Our aim in this in-vitro study was to investigate the susceptibility of various Plastic Bracket materials to the adherence of Streptococcus mutans . Methods The esthetic Bracket raw materials included in this study were polyoxymethylene, polycarbonate, high-density polyethylene, and an experimental polymer (90% polyethylene). Surface roughness was assessed by perthometer. S mutans suspension was incubated with test specimens and examined with fluorescence dye and an automated multi-detection reader. The oxidation-reduction fluorescence dye Alamar Blue/resazurin (0.007536 g per 10 mL distilled water) was used to determine the quantity of bacterial adhesion. Results The median values of fluorescence intensity varied between approximately 600 and 1600. The lowest fluorescence with median values below 700, indicating low bacterial adhesion, was found for polyoxymethylene (median of relative fluorescence intensity, 635). The highest relative fluorescence intensity, with median values of more than 1500, was for high-density polyethylene (1565). No statistical alteration of fluorescence intensity was measured between the polymeric Bracket materials. Conclusions The investigated polymeric Bracket materials had no significant differences in the quantities of S mutans adhering to them. Regardless of the polymer, Plastic Bracket materials have similar bacterial colonization and plaque accumulation properties.

  • Influence of fibre and filler reinforcement of Plastic Brackets: an in vitro study
    The European Journal of Orthodontics, 2007
    Co-Authors: Andreas Faltermeier, Martin Rosentritt, Rupert Faltermeier, Dieter Müßig
    Abstract:

    In spite of their popularity in fulfilling aesthetic requirements, Plastic Brackets still present some disadvantages because of their low elastic modulus, decreased fracture toughness, and reduced wear resistance. Fibre-reinforced composites are well established in dentistry and consist of a polymer matrix in which reinforcing fibres are embedded. Stress is transferred from the polymer matrix to the fibres which present a high tensile strength. Hence, the mechanical properties of polymers could be improved. The purpose of this study was to compare fracture strength, fracture toughness and flexural strength of an experimental fibre-reinforced Bracket material, an SiO(2) filler-reinforced Bracket and an unfilled Plastic Bracket material (control group). Experimental Brackets and specialized bars were manufactured. Tests were performed after thermal cycling (5 degrees C/55 degrees C) the samples in an artificial oral environment of a device to simulate mastication. Statistical evaluation was undertaken. The median, 25th and 75th percentiles were calculated and a Mann-Whitney U-test was performed. In this study two findings were obvious. (1) Filler reinforcement of Plastic Brackets improved fracture strength and fracture toughness in comparison with the unfilled Bracket material. (2) Glass fibre reinforcement of orthodontic Bracket materials resulted in the greatest enhancement of the mechanical properties in comparison with the other test groups. Therefore, the application of glass fibres in Plastic Brackets is a successful method to enhance fracture strength.

Geert Verbeke - One of the best experts on this subject based on the ideXlab platform.

  • In vitro peel/shear bond strength evaluation of orthodontic Bracket base design.
    Journal of Dentistry, 1997
    Co-Authors: Guy Willems, Carine Carels, Geert Verbeke
    Abstract:

    Abstract Objectives: The adhesive capacity of 17 different Bracket types was evaluated in an in vitro peel/shear test. Methods: Silane-treated metal bars were used as substrates with all bonding being performed using the orthodontic adhesive Concise. The effect of aluminium oxide air abrasion on the bonding performance of recycled metal Bracket bases was evaluated. Morphological examination of the Bracket bases was carried out under scanning electron microscopy. Statistics analysis included one-way ANOVA with Tukey's Studentized Range Test, two-way ANOVA and Weibull analysis. Results: Mean peel/shear bond strength values range from 13.9 MPa for Allure Accu Arch, a ceramic Bracket type, to 1.6 MPa for the Plastic Bracket CeramaFlex Advant Edge. Allure Accu Arch performed the best of all the ceramic Brackets. However, Bracket wing fracture was observed. The metal Brackets Mini masters and Omni Arch showed no significant difference in bond strength compared with the ceramic Bracket Allure Accu Arch (P Conclusion: The type of the Bracket base determines its adhesive capacity. Sandblasting the base of recycled metal Brackets had no uniform effect.

  • In vitro peel/shear bond strength evaluation of orthodontic Bracket base design.
    Journal of Dentistry, 1997
    Co-Authors: Guy Willems, Carine Carels, Geert Verbeke
    Abstract:

    The adhesive capacity of 17 different Bracket types was evaluated in an in vitro peel/shear test. Silane-treated metal bars were used as substrates with all bonding being performed using the orthodontic adhesive Concise. The effect of aluminium oxide air abrasion on the bonding performance of recycled metal Bracket bases was evaluated. Morphological examination of the Bracket bases was carried out under scanning electron microscopy. Statistics analysis included one-way ANOVA with Tukey's Studentized Range Test, two-way ANOVA and Weibull analysis. Mean peel/shear bond strength values range from 13.9 MPa for Allure Accu Arch, a ceramic Bracket type, to 1.6 MPa for the Plastic Bracket CeramaFlex Advant Edge. Allure Accu Arch performed the best of all the ceramic Brackets. However, Bracket wing fracture was observed. The metal Brackets Mini masters and Omni Arch showed no significant difference in bond strength compared with the ceramic Bracket Allure Accu Arch (P < 0.01). The type of the Bracket base determines its adhesive capacity. Sandblasting the base of recycled metal Brackets had no uniform effect.

Takashi Ono - One of the best experts on this subject based on the ideXlab platform.

  • Effectiveness of low binding frictional materials: Evaluation of the binding frictional resistance of improved superelastic nickel-titanium alloy wires with different Bracket combinations
    APOS Trends in Orthodontics, 2019
    Co-Authors: Yoshio Shima, Akihiro Koyama, Takashi Ono
    Abstract:

    Introduction: This study aimed to evaluate the binding frictional resistance of improved superelastic nickel- titanium alloy wires (ISW) with different Bracket combinations and to verify the effectiveness of low binding frictional materials by applying them in orthodontic treatment. Materials and Methods: Straight stainless steel wire (SSW; 0.016 × 0.022-inch) and straight ISW (0.016 × 0.022- inch) were set to each displaced Bracket, and the tensile resistance load was measured. The maximum tensile resistance load was statistically compared using the Tukey test. For exemplification, we treated a typical extraction case of Angle Class I crowding malocclusion with lip protrusion using lower binding frictional materials, which were selected based on tensile test results. Results: The SSW and metal Bracket combination had the largest maximum tensile resistance load, and the ISW and metal slot-equipped Plastic Bracket combination had the smallest load (P < 0.01). In a patient treated using lower binding frictional materials, the active treatment period was 9 months. Satisfactory patient results were obtained without using reinforced anchorage. Conclusions: Binding frictional resistance varies, depending on the archwire and Bracket combination. In a multiBracket appliance, selecting materials with as low a binding frictional resistance as possible may make a more effective treatment.

Theodore Eliades - One of the best experts on this subject based on the ideXlab platform.

  • Orthodontic materials research and applications: part 2. Current status and projected future developments in materials and biocompatibility.
    American Journal of Orthodontics and Dentofacial Orthopedics, 2007
    Co-Authors: Theodore Eliades
    Abstract:

    The purpose of this 2-part opinion article was to project the developments expected to occur in the next few years in orthodontic materials research and applications. Part 1 reviewed developments in bonding to enamel. Part 2 looks at other orthodontic materials applications and explores emerging research strategies for probing the biological properties of materials. In the field of metallic Brackets, expansion of the use of titanium alloys with improved hardness and nickel-free steels with better corrosion resistance and increased hardness is expected. Manufacturing techniques might be modified to include laser-welding methods and metal injection molding. Esthetic Bracket research will involve the synthesis of high-crystallinity biomedical polymers with increased hardness and stiffness, decreased water sorption, and improved resistance to degradation. New Plastic Brackets might incorportate ceramic wings. Fiber-reinforced composite archwires, currently experimental, could soon be commercially available, and long-term applications of shape-memory Plastics might become viable. Advancements in elastomeric materials will result in polymers with reduced relaxation, broader use of fluoride-releasing elastomers with decreased relaxation, and large-scale film coating of elastomers to decrease reactivity, water sorption, and degradation. Finally, biocompatibility assessments will incorporate testing of potential endocrinological action. New polymer formulations might be tested in adhesive and Plastic Bracket manufacturing, based on benzoic ring-free monomers to avoid the adverse effects of the estrogenic molecule bisphenol-A.

  • Comparative assessment of the roughness, hardness, and wear resistance of aesthetic Bracket materials
    Dental Materials, 2005
    Co-Authors: Spiros Zinelis, Theodore Eliades, George Eliades, Margarita Makou, Nikolaos Silikas
    Abstract:

    Summary Objective The purpose of this study was to assess critical properties of orthodontic aesthetic Bracket materials. Method Samples of polycarbonate, poly(oxy)methylene, ultra high molecular weight polyethylene (UHMWPE), and polycrystalline alumina raw material used from Bracket manufacturing were subjected to: (a) profilometry for the determination of Ra, Rq, Rmax and Rz roughness parameters; (b) Vickers hardness (HV50) testing; and (c) wear resistance determined by the scratch test. The results were analyzed with one-way ANOVA and Tukey multiple comparisons test at α=0.05 level of significance. Results The UHMWP and alumina specimens showed the highest roughness values for all parameters. The highest hardness, amongst the polymeric raw materials, was obtained from the poly(oxy)methylene appliances. Differences were also noted between the polycarbonate raw material of different manufacturers implying an effect from the manufacturing process. With the exception of alumina, the highest wear resistance was found for the poly(oxy)methylene specimens. Significance The results of this study reveal the variability among aesthetic Plastic Bracket raw materials, their reduced hardness and wear resistance relative to alumina as well as the inappropriateness of UHMWPE as alternative Bracket material.