17 results on '"Handel G"'
Search Results
2. The impact of cement mixing and storage errors on the risk of failure of glass–ceramic crowns
- Author
-
Loher, H., Behr, M., Hintereder, U., Rosentritt, M., and Handel, G.
- Published
- 2009
- Full Text
- View/download PDF
3. Concepts for the treatment of adolescent patients with missing permanent teeth
- Author
-
Behr, M., Driemel, O., Mertins, V., Gerlach, T., Kolbeck, C., Rohr, N., Reichert, T. E., and Handel, G.
- Published
- 2008
- Full Text
- View/download PDF
4. Fracture resistance of fiber-reinforced vs. non-fiber-reinforced composite molar crowns
- Author
-
Behr, M., Rosentritt, M., Latzel, D., and Handel, G.
- Published
- 2003
- Full Text
- View/download PDF
5. Frequency and costs of technical failures of clasp- and double crown-retained removable partial dentures
- Author
-
Hofmann, E., Behr, M., and Handel, G.
- Published
- 2002
- Full Text
- View/download PDF
6. Technical failure rates of double crown-retained removable partial dentures
- Author
-
Behr, M., Hofmann, E., Rosentritt, M., Lang, R., and Handel, G.
- Published
- 2000
- Full Text
- View/download PDF
7. Comparison of failure rates of adhesive-fixed partial dentures for in vivo and in vitro studies
- Author
-
Behr, M., Hindelang, U., Rosentritt, M., Lang, R., and Handel, G.
- Published
- 2000
- Full Text
- View/download PDF
8. Adhesive-fixed partial dentures in anterior and posterior areas: Results of an on-going prospective study begun in 1985
- Author
-
Behr, M., Leibrock, A., Stich, W., Rammelsberg, P., Rosentritt, M., and Handel, G.
- Published
- 1998
- Full Text
- View/download PDF
9. Zur Lage der Wassermoleküle in Kieserit MgSO4·H2O
- Author
-
Handel, G., Schnabel, B., and Heide, K.
- Published
- 1967
- Full Text
- View/download PDF
10. Influence of proximal box elevation technique on marginal integrity of adhesively luted Cerec inlays.
- Author
-
Müller V, Friedl KH, Friedl K, Hahnel S, Handel G, and Lang R
- Subjects
- Dental Cements, Dental Stress Analysis, Humans, In Vitro Techniques, Materials Testing, Methacrylates, Microscopy, Electron, Scanning, Molar, Phosphates, Ceramics, Composite Resins chemistry, Dental Marginal Adaptation, Dental Restoration, Permanent methods, Inlays, Resin Cements chemistry
- Abstract
Objectives: This in vitro study evaluated the marginal quality of Lava Ultimate inlays in deep proximal cavities with and without proximal box elevation (PBE) before and after thermomechanical loading (TML)., Materials and Methods: Mesio-occluso-distal cavities with proximal boxes beneath the cementoenamel junction (CEJ) were prepared in 24 human molars. Then, one of the proximal boxes was elevated with Filtek Supreme above the CEJ. The specimens were divided into three groups (n = 8). The inlays of group A were adhesively luted to the cavities with Scotchbond Universal and Rely X Ultimate, the inlays of group B with Monobond Plus, Syntac, and Variolink II, and the inlays of group C with Clearfil Ceramic Primer and Panavia SA Cement. Epoxy resin replicas were taken before and after thermomechanical loading (1,200,000 cycles, 55 °C/5 °C, max. load 50 N). Marginal integrity at the different interfaces tooth/PBE, tooth/dentine, inlay/PBE, inlay/dentine was evaluated with scanning electron microscopy (×200). The percentage of continuous margin (% of total proximal margin length) was compared between the groups before and after TML., Statistics: Mann-Whitney U test (p = 0.05)., Results: No significant differences (p > 0.05) before and after TML were found between the three groups for bonding the inlay to dentine or to PBE composite., Conclusions: The marginal integrities of bonding inlays directly to dentine are not different from bonding inlays to a proximal box, which has been elevated by a composite filling material. For deep proximal cavities, the PBE technique could be an alternative technique to conventional methods. Clinical research is needed to confirm.
- Published
- 2017
- Full Text
- View/download PDF
11. Two-body wear of dental porcelain and substructure oxide ceramics.
- Author
-
Rosentritt M, Preis V, Behr M, Hahnel S, Handel G, and Kolbeck C
- Subjects
- Aluminum Oxide, Analysis of Variance, Dental Stress Analysis, Humans, Magnesium Oxide, Mastication, Microscopy, Electron, Scanning, Silicon Dioxide, Statistics, Nonparametric, Zirconium, Dental Enamel, Dental Porcelain, Dental Restoration Wear, Tooth Wear
- Abstract
The aim of this in vitro study was to investigate the two-body wear of different ceramics. Two-body wear tests were performed in a chewing simulator with steatite and enamel antagonists, respectively. Specimens were loaded in a pin-on-block design with a vertical load of 50 N for 1.2 × 10(5) cycles; (f = 1.6 Hz; lateral movement, 1 mm; mouth opening: 2 mm). Human enamel was used as a reference. Three zirconia ceramics, three veneering porcelains, two glass-infiltrated and one lithium disilicate ceramic were investigated. Veneering and lithium disilicate ceramics were glazed before testing. Surface roughness Ra (SP6, Perthen-Feinprüf, G) and wear depth were determined using a 3D scanner (Laserscan 3D, Willytec, G). SEM (Quanta FEG 400, FEI, USA) pictures of the worn specimens and antagonists were made for evaluating wear performance. Veneering porcelain provided wear traces between 71.2 and 124.1 μm (enamel antagonist) and 117.4 and 274.1 μm (steatite). Wear of the steatite antagonists varied between 0.618 and 2.85 mm². No wear was found for zirconia and glass-infiltrated substructure ceramics. Also, no wear was found for the corresponding antagonists. Wear of specimens and antagonists was strongly material dependent. No visible wear was found on zirconia and glass-infiltrated ceramics. Porcelain and lithium disilicate ceramic showed a comparable or lower wear than the enamel reference. Antagonist wear was found to be lower when specimens were made of substructure oxide ceramics instead of veneering porcelain. From the point of wear testing, zirconia may be used for the fabrication of fixed dental prosthesis without veneering.
- Published
- 2012
- Full Text
- View/download PDF
12. Bond of acrylic teeth to different denture base resins after various surface-conditioning methods.
- Author
-
Lang R, Kolbeck C, Bergmann R, Handel G, and Rosentritt M
- Subjects
- Aluminum Oxide chemistry, Dental Etching methods, Dental Restoration Failure, Dental Stress Analysis instrumentation, Humans, Materials Testing, Methylmethacrylate chemistry, Polymethyl Methacrylate chemistry, Silanes chemistry, Silicon Dioxide chemistry, Stress, Mechanical, Surface Properties, Temperature, Time Factors, Water chemistry, Acrylic Resins chemistry, Dental Bonding, Dental Materials chemistry, Denture Bases, Tooth, Artificial
- Abstract
The study examined the bond between different denture base resins and highly cross-linked acrylic denture teeth with different base surface-conditioning methods. One hundred fifty highly cross-linked resin denture teeth (SR-Antaris, No. 11, Ivoclar-Vivadent, FL) were divided into five groups with different surface-conditioning methods of the base surfaces of the teeth (C = control, no surface conditioning, MM = application of methyl methacrylate monomer, SB = sand blasting, SBB = sand blasting + bonding agent, TSS = tribochemical silica coating + silanization). Teeth were bonded to either a cold-cured denture base resin (ProBase Cold, Ivoclar-Vivadent, FL) or heat-cured denture base resins (SR Ivocap Plus, Ivoclar-Vivadent, FL and Lucitone 199, Dentsply, USA). After 24 h of storage in distilled water, compressive load was applied at 90° on the palatal surface of each tooth until fracture. Median failure load ranged between 103 and 257 N for Probase Cold groups, 91 to 261 N for Lucitone 199, and 149 to 320 N for SR Ivocap Plus. For Probase Cold, significant highest failure loads resulted when teeth were treated with SB, SBB, or TSS. For Lucitone 199, significant highest failure loads has been found with MM and TSS treatment. For SR Ivocap Plus, highest failure loads resulted using SBB and TSS. Conditioning of the base surfaces of the teeth prior to denture base processing is highly recommended. Tooth bond is significantly affected by the surface-conditioning method and applied denture base resin. Tribochemical silica coating + silanization method can be recommended for pre-treatment of teeth applying either heat-cured or cold-cured denture base resin.
- Published
- 2012
- Full Text
- View/download PDF
13. Analysis of marginal adaptation and sealing to enamel and dentin of four self-adhesive resin cements.
- Author
-
Aschenbrenner CM, Lang R, Handel G, and Behr M
- Subjects
- Acid Etching, Dental methods, Cementation methods, Coloring Agents, Composite Resins chemistry, Dental Cavity Preparation classification, Dental Cements chemistry, Dental Leakage classification, Humans, Hydrofluoric Acid chemistry, Lithium Compounds chemistry, Microscopy, Electron, Scanning, Molar, Third, Rosaniline Dyes, Silanes chemistry, Stress, Mechanical, Surface Properties, Temperature, Time Factors, Water chemistry, Dental Bonding, Dental Enamel ultrastructure, Dental Marginal Adaptation, Dentin ultrastructure, Inlays, Resin Cements chemistry
- Abstract
This in vitro study compared the marginal adaptation of all-ceramic MOD-inlays luted to human molars with four self-adhesive resin cements. Thirty-two human third molars were randomly assigned to four test groups (n = 8 per group). MOD cavities were prepared with approximal finishing lines in dentin and enamel. All-ceramic Empress 2 inlays were luted with four self-adhesive cements (Clearfil SA, iCEM, Bifix SE, seT). Oral stress was simulated by 90 day storage in water as well as by thermal and mechanical loading (TCML, 1.2 × 10(6) × 50 N, 6,000 × 5°/55°, 1.6 Hz). The marginal fit was evaluated by scanning electron microscopy (SEM) and dye penetration. Data were analyzed with the ANOVA/Tukey's test (α = 0.05). The SEM investigation of the gingival cement margins (cement-tooth interface) showed values of perfect margin [percent] (means ± SD) after simulated aging between 84 ± 9% and 95 ± 5% for enamel and 80 ± 9% and 92 ± 3% for dentin. In enamel, seT showed significantly higher marginal integrity than iCEM after water storage and TCML (post hoc; p = 0.011). Furthermore, the marginal adaptation of iCEM in enamel deteriorated by simulated aging (p = 0.014, ANOVA). Mean values of dye penetration (percentage of dye entry into dentin) at the investigated restorations margins ranged between 3% and 8% for enamel and 12% and 22% for dentin. Clearfil SA, iCEM, and seT showed lower dye penetration in enamel than in dentin (Clearfil SA: p = 0.013, iCEM: p = 0.044, seT: p = 0.003). The results suggest that the four self-adhesive luting agents investigated seem to successfully bond to dentin-restricted as well as to enamel-restricted cavities, predicting good clinical performance.
- Published
- 2012
- Full Text
- View/download PDF
14. Influence of the fabrication process on the in vitro performance of fixed dental prostheses with zirconia substructures.
- Author
-
Rosentritt M, Kolbeck C, Handel G, Schneider-Feyrer S, and Behr M
- Subjects
- Biomechanical Phenomena, Bite Force, Cementation methods, Computer-Aided Design, Crowns, Dental Abutments, Dental Porcelain chemistry, Dental Restoration Failure, Dental Restoration Wear, Dental Stress Analysis instrumentation, Dental Technicians standards, Dental Veneers, Dentin-Bonding Agents chemistry, Humans, Laboratories, Dental standards, Microscopy, Electron, Scanning, Resin Cements chemistry, Stress, Mechanical, Surface Properties, Temperature, Dental Materials chemistry, Denture Design methods, Denture, Partial, Fixed, Zirconium chemistry
- Abstract
Chipping of the applied veneering ceramic is reported to be a main clinical failure type of computer-aided design/computer-aided manufacturing- or manually copy-milled zirconia restorations. The aim of this in vitro study was to investigate whether different substructure designs and veneering processes done by different dental technicians do significantly influence chipping in zirconia-based all-ceramic fixed dental prostheses during simulated oral service. Five groups (n = 8 per group) of three-unit zirconia substructures were fabricated in three different laboratories using copy-milling technique. Three series were veneered with identical porcelain (groups 1-3) and one with a second different porcelain (group 4). The fifth group was milled to final contour design without veneering. Dimensions of the connector areas were determined. All fixed partial dentures (FPDs) were adhesively boned on human teeth and thermally cycled and mechanically loaded (1.2 × 10(6) × 50 N; 6,000 × 5°C/55°C) using human antagonists. Restorations were monitored during thermal cycling and mechanical loading (TCML). FPDs which survived were loaded to fracture. FPDs which failed during TCML were investigated with fractographic means. During TCML, chipping took place in groups 1 (two times), 2 (four times) and 3 (five times) (Table 1). Chipping areas varied between 2.3 mm(2) (group 3) and 58.7 mm(2) (group 2). Groups 4 and 5 provided no failures during TCML. Failure in all cases started from contact points, where superficial wear and disruption of the porcelain were found. No significant correlation could be determined between connector thickness and number of failures. Median fracture results varied between 1,011 N (group 3) and 2,126 N (group 2). The results show the necessity of considering individual design and manufacturing of restorations as well as contact situation. Advanced technical training on zirconia-based restorations is recommended.
- Published
- 2011
- Full Text
- View/download PDF
15. Effects of aging on surface properties and adhesion of Streptococcus mutans on various fissure sealants.
- Author
-
Bürgers R, Cariaga T, Müller R, Rosentritt M, Reischl U, Handel G, and Hahnel S
- Subjects
- Bisphenol A-Glycidyl Methacrylate chemistry, Compomers chemistry, Composite Resins chemistry, Dental Polishing, Glass chemistry, Glass Ionomer Cements chemistry, Humans, Materials Testing, Resin Cements chemistry, Resins, Synthetic chemistry, Surface Properties, Temperature, Time Factors, Water chemistry, Bacterial Adhesion, Pit and Fissure Sealants chemistry, Streptococcus mutans physiology
- Abstract
The aim of the present study was the quantification of Streptococcus mutans adhesion on ten widely used pit and fissure sealant materials and the correlation of these findings to surface roughness (R(a)) and surface free energy (SFE). Additionally, changes in streptococcal adhesion and surface parameters after water immersion and artificial aging have been investigated. Circular specimens of ten fissure sealants (seven resin-based composites, two glass ionomers, and one compomer) were made and polished. Surface roughness was determined by perthometer and SFE by goniometer measurements. Sealant materials were incubated with S. mutans suspension (2.5 h, 37 degrees C), and adhering bacteria were quantified by using a biofluorescence assay in combination with an automated plate reader. Surface properties and S. mutans adhesion were measured prior to and after water immersion after 1 and 6 months and after additional thermocycling (5,000 cycles; 5 degrees C/55 degrees C). The tested sealants showed significant differences in S. mutans adhesion prior to and after the applied aging procedures. Aging resulted in slight increases (mostly <0.2 microm) in surface roughness, as well as in significant decreases in SFE and in significantly lower quantities of adhering bacteria. Ketac Bond and UltraSeal XT plus revealed the lowest adhesion potential after artificial aging. In general, the amount of adhering S. mutans was reduced after aging, which may be related to the decline in SFEs.
- Published
- 2009
- Full Text
- View/download PDF
16. Fracture characteristics of anterior resin-bonded zirconia-fixed partial dentures.
- Author
-
Rosentritt M, Ries S, Kolbeck C, Westphal M, Richter EJ, and Handel G
- Subjects
- Ceramics chemistry, Computer-Aided Design, Cuspid, Dental Bonding, Dental Etching, Dental Restoration Failure, Dental Stress Analysis, Dental Veneers, Denture Design, Denture Retention, Humans, Incisor, Materials Testing, Resin Cements chemistry, Silanes chemistry, Stress, Mechanical, Temperature, Time Factors, Tooth Preparation, Prosthodontic methods, Dental Materials chemistry, Denture, Partial, Fixed, Resin-Bonded, Zirconium chemistry
- Abstract
Resin-bonded fixed partial dentures (RBFPD) are used as a minimal invasive, tooth-preventing alternative for replacing anterior teeth. Zirconia cantilever restorations were supposed to show sufficient strength for a clinical application. The aim of this investigation was to determine the fracture characteristics of cantilever and two-retainer RBFPD, which are fabricated by computer-manufactured high-strength zirconia. Human incisors and canines were used to form three groups of 14 RBFPDs with different types of preparation: group 1, an invasive cantilever; group 2, a minimal-invasive cantilever and group 3, a two-retainer RBFPD control. After thermal cycling and mechanical loading, which was performed to simulate oral service, all restorations were loaded to fracture in a universal testing machine. One half of the specimens were investigated as a control without simulated service. Mode of failure was determined for the three designs. Both cantilever groups showed comparable fracture resistance of 227 N (no. 1) and 210 N (no. 2) before thermal cycling and mechanical loading. The resistance after aging was reduced to 210 N for the invasive cantilever RBFPD and to 179 N for the minimal invasive group. Three-unit RBFPDs showed a significantly higher (p < 0.02) fracture resistance than cantilever bridges before (426 N) as well as after aging (360 N). Predominant failure was FPD and retainer fracture for the invasive cantilever design, debonding for the minimal cantilever design and RBFPD fracture for the two-retainer design. The present study revealed a significantly higher fracture resistance for two-retainer RBFPDs than for cantilever RBFPDs. The frequency of adhesive debonding increased for non-retentive prepared cantilever RBFPDs.
- Published
- 2009
- Full Text
- View/download PDF
17. Candida albicans adhesion to composite resin materials.
- Author
-
Bürgers R, Schneider-Brachert W, Rosentritt M, Handel G, and Hahnel S
- Subjects
- Colony Count, Microbial, Compomers, Dental Restoration, Permanent, Hydrophobic and Hydrophilic Interactions, Luminescent Measurements, Microscopy, Electron, Scanning, Surface Properties, Candida albicans physiology, Cell Adhesion, Composite Resins
- Abstract
The adhesion of Candida albicans to dental restorative materials in the human oral cavity may promote the occurrence of oral candidosis. This study aimed to compare the susceptibility of 14 commonly used composite resin materials (two compomers, one ormocer, one novel silorane, and ten conventional hybrid composites) to adhere Candida albicans. Differences in the amount of adhering fungi should be related to surface roughness, hydrophobicity, and the type of matrix. Cylindrical specimens of each material were made according to the manufacturers' instructions. Surface roughness R (a) was assessed by perthometer measurements and the degree of hydrophobicity by computerized contact angle analysis. Specimens were incubated with a reference strain of C. albicans (DMSZ 1386), and adhering fungi were quantified by using a bioluminometric assay in combination with an automated plate reader. Statistical differences were analyzed by the Kruskal-Wallis test and Mann-Whitney U test. Spearman's rank correlation coefficients were calculated to assess correlations. Median R (a) of the tested composite resin materials ranged between 0.04 and 0.23 microm, median contact angles between 69.2 degrees and 86.9 degrees . The two compomers and the ormocer showed lower luminescence intensities indicating less adhesion of fungi than all tested conventional hybrid composites. No conclusive correlation was found between surface roughness, hydrophobicity, and the amount of adhering C. albicans.
- Published
- 2009
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.