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Research Interests: Materials Science, Dentistry, Medicine, Humans, Endodontology, and 15 moreCompressive Strength, Conservative Dentistry, Maxilla, Adhesive Dentistry, ALL CERAMIC CROWNS AND BRIDGES, Inlay, Dental Porcelain, Composite resins, Analysis of Variance, Dental Stress Analysis, Dental Bonding, All Ceramics, Dental Crown, Dental restoration failure, and Bicuspid
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The purpose of this research was to evaluate the influence of aging and surface treatment on surface roughness, biaxial flexural strength (BFS), and Vickers hardness (VHN) of translucent dental zirconia. Half of 80 disc-shaped zirconia... more
The purpose of this research was to evaluate the influence of aging and surface treatment on surface roughness, biaxial flexural strength (BFS), and Vickers hardness (VHN) of translucent dental zirconia. Half of 80 disc-shaped zirconia specimens (1.2 mm thickness and 12 mm diameter) were aged (group A) in an autoclave for 20 h (134 °C and 0.2 MPa) and the other half were not aged (group N). Specimens were subjected to: no surface treatment (SIN), particle air-abrasion with 50 µm alumina particles at 1 bar (0.1 MPa) and 2.5 bar (0.25 MPa), or polishing down to 1 µm (POL). Specimens were analyzed using X-ray diffraction, laser scanning microscope, BFS, and VHN tests. Three groups (N-SIN, N-POL, and A-POL) showed almost no monoclinic phase. While other groups showed monoclinic phase ratios ranging from 7.5 vol. % ± 2.4 vol. % (N-0.1 MPa) to 41.5 vol. % ± 0.3 vol. % (A-0.1 MPa). Aging and particle air-abrasion increased significantly the BFS, ranging from 720 ± 37 MPa (N-SIN) to 1153 ± ...
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This study evaluated the effect of surface treatment of zirconia in pre-sintered and post-sintered stages on its surface roughness, phase transformation, and biaxial flexural strength (BFS). Zirconia ceramic discs (n=40) having a final... more
This study evaluated the effect of surface treatment of zirconia in pre-sintered and post-sintered stages on its surface roughness, phase transformation, and biaxial flexural strength (BFS). Zirconia ceramic discs (n=40) having a final dimensions of 12mm diameter and 1.2mm thickness were milled then divided into three main groups according to the type of surface treatment performed (Group 1 (n=16); air-abrasion using AlO particles, Group 2 (n=16); silica coating using Rocatec soft, and Group 3 (n=8); a control group receiving no surface treatment). Groups 1 and 2 were divided into two subgroups each according to the stage in which the surface treatment was performed (Subgroup A; surface treatment performed in the pre-sintered stage and subgroup B; surface treatment performed in the post-sintered stage). Surface roughness, phase transformation, and biaxial flexural strength (BFS) were later assessed. Data was then analyzed using two-way ANOVA and Tukey post-hoc tests at a significanc...
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The aim of this study was to test five types of implant restorations using titanium, zirconia and lithium disilicate abutments after being subjected to long-term fatigue loading. Forty single-tooth implant restorations were assembled on... more
The aim of this study was to test five types of implant restorations using titanium, zirconia and lithium disilicate abutments after being subjected to long-term fatigue loading. Forty single-tooth implant restorations were assembled on titanium implants (FairTwo; FairImplant). The restorations differed only in the type of abutment used and were divided into five groups [Ti: titanium; Zr: zirconia with no metal base; ZrT: zirconia with titanium base; LaT: lithium disilicate abutment with titanium base; and LcT: lithium disilicate hybrid-abutment-crown with titanium base]. Specimens were subjected to dynamic load of 49 N up to 1,200,000 cycles using a dual-axis chewing simulator (Kausimulator; Willytech). The surviving specimens were subjected to quasi-static loading using a universal testing machine (Z010; Zwick) until the implant-abutment connection failed. The values of force (N) at which fracture or plastic deformation of the restoration occurred were calculated and the rate of d...
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Research Interests: Materials Science, Dentistry, Biomedical Engineering, Osseointegration, Titanium, and 15 moreDental Implants, Medicine, Animals, Mandible, Maxilla, Dental Porcelain, Implant, Analysis of Variance, Swine, Epithelial Attachment, Dental Prosthesis Design, Soft Tissue, Adhesives, Abutment, and Alveolar bone loss
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Research Interests: Materials Science, Dentistry, Biomedical Engineering, Glass, Dental Materials, and 15 moreMedicine, Humans, Prosthetic Dentistry, Dental Caries, Maxilla, Composite resins, Incisor, Dental Prosthesis Design, Crowns, Dental Stress Analysis, Materials Testing, Resin Cements, Dental Cements, In Vitro Techniques, and Dental restoration failure
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The purpose of this study was to evaluate the effect of a horizontal glass fiber post on the fracture strength of endodontically treated maxillary premolars with mesioocclusaldistal (MOD) cavities. Sixty extracted intact upper premolars... more
The purpose of this study was to evaluate the effect of a horizontal glass fiber post on the fracture strength of endodontically treated maxillary premolars with mesioocclusaldistal (MOD) cavities. Sixty extracted intact upper premolars were collected, treated endodontically (except for the control group), and divided into 5 test groups (n = 12) depending on the restoration type: G1 (control group, untreated teeth), G2 (MOD preparation without restoration), G3 (MOD preparation with resin composite restoration), G4 (MOD preparation with resin composite restoration and a horizontal fiber post inserted between buccal and palatal walls), and G5 (MOD preparation with a horizontal fiber post only). The specimens were stored in normal saline at 37°C for 2 months. Then specimens were quasi-statically loaded in a universal testing machine until fracture occurred. Failure loads were then analyzed with one-way analysis of variance, followed by multiple comparisons by using Tukey honestly signi...
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Single-retainer resin-bonded fixed dental prostheses (RBFDPs) present a minimally invasive treatment option as an alternative to implant-retained restorations in the esthetic zone. Advantages such as applicability to juvenile patients who... more
Single-retainer resin-bonded fixed dental prostheses (RBFDPs) present a minimally invasive treatment option as an alternative to implant-retained restorations in the esthetic zone. Advantages such as applicability to juvenile patients who do not come into consideration for implant therapy, and highly predictable and esthetic results make them a valuable treatment modality. This article outlines the treatment procedures with an all-ceramic RBFDP and reviews the existing data on the clinical outcome of this prosthetic therapy. The materials used for fabrication and insertion of the RBFDPs as well as the current scientific data are discussed.
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Dentistry has not been exempt from changes in this era of technology-driven revolution. Entire workflows are already digitalized, and restorations are designed and manufactured using computer-aided solutions. This case report describes... more
Dentistry has not been exempt from changes in this era of technology-driven revolution. Entire workflows are already digitalized, and restorations are designed and manufactured using computer-aided solutions. This case report describes the reconstruction of 24 teeth using digital techniques.
Research Interests: Engineering, Dentistry, Prosthodontics, Computer Aided Design, Workflow, and 15 moreMedicine, Humans, Female, Quintessence, Computer User Interface Design, Middle Aged, Dental Porcelain, Composite resins, Dental technology, Dental Prosthesis Design, Root Canal Therapy, Dental Veneers, Resin Cements, full mouth rehabilitation, and Dental Impression Technique
Despite the success in preventing oral diseases, the prevalence of tooth loss in the German population remains high and increases with age. Today, the advances in prosthetic dentistry allow necessary tooth replacement following preventive... more
Despite the success in preventing oral diseases, the prevalence of tooth loss in the German population remains high and increases with age. Today, the advances in prosthetic dentistry allow necessary tooth replacement following preventive strategies-after considering benefits and risks. Modern treatment options improve the overall prognosis of the stomatognathic system and the quality of life of the affected patients significantly. Hereby, adverse iatrogenic effects can be minimized or even completely avoided by extending the traditional treatment spectrum, e.g., using adhesively fixed restorations and implant-supported restorations, and refraining from placing restorations that are unnecessary from the medical point of view. Generally, patients benefit greatly from prosthetic treatment and the achieved health gain is remarkably high. It encompasses not only the recovery of the impaired oral functions but also extends to the whole human organism, including nutrition, digestion, musc...
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Various ceramic implant systems made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have become commercially available in recent years. A systematic search of the literature was performed to assess the clinical success of... more
Various ceramic implant systems made of yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) have become commercially available in recent years. A systematic search of the literature was performed to assess the clinical success of dental Y-TZP implants and whether the osseointegration of Y-TZP is comparable to that of titanium, the standard implant material. The internet database MEDPILOT was searched cumulatively for the keywords zircon* and dent* and implant as well as for zircon* and osseointegration. The last search was conducted on January 31st, 2007. Subsequently, the reference lists of the relevant publications were searched. Furthermore, a letter was sent to the 5 identified manufacturers of zirconia dental implants to ask for peer-reviewed publications. Ninety-six articles were found by the search strategy. No controlled clinical studies in humans regarding clinical outcomes or osseointegration could be identified. Clinical data were restricted to case studies and cas...
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The aim of this study was to evaluate the effect of 2 surface conditioning methods and 2 luting-gap sizes on the retention and durability of zirconia ceramic copings bonded to titanium abutments. Zirconia ceramic copings (Camlog... more
The aim of this study was to evaluate the effect of 2 surface conditioning methods and 2 luting-gap sizes on the retention and durability of zirconia ceramic copings bonded to titanium abutments. Zirconia ceramic copings (Camlog Biotechnologies, Winsheim, Germany) with a luting-gap size of either 30 microm or 60 microm were bonded to titanium abutments (Camlog Biotechnologies) using the composite resin cement Panavia F (Kuraray, Osaka, Japan). The bonding surfaces of the zirconia ceramic copings were either (a) pretreated with airborne particle abrasion and cleaned with alcohol or (b) just cleaned with alcohol, whereas the bonding surfaces of all titanium abutments had been abraded and cleaned. After the specimens had been stressed for either 1, 30, 60, or 150 days by water and thermal cycling, retention was measured. The surface conditioning method, luting-gap size, and storage time significantly (P = .001; 3-way analysis of variance [ANOVA]) influenced retention. Air abrasion incr...
Research Interests: Materials Science, Dentistry, Biomedical Engineering, Osseointegration, Titanium, and 15 moreMedicine, Adhesive, Pubmed, Ceramic, Dental Porcelain, Composite resins, Zirconium, Analysis of Variance, Surface Properties, Crowns, Dental Stress Analysis, Dental Bonding, Materials Testing, Dental Cements, and Dental restoration failure
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Research Interests:
Research Interests: Materials Science, Dentistry, Dental Research, Computer Aided Design, Dental Materials, and 15 moreHumans, Composite, Dental, Ceramic, Fixed Prosthodontics, Cad Cam Cae, Dental Porcelain, Composite resins, Dental prostheses, Dental Prosthesis Design, Denture Retention, Cad Cam, Dental Enamel, Materials Testing, and Abutment
Research Interests: Materials Science, Dentistry, Biomedical Engineering, Peer Review, Dental Materials, and 15 moreMedicine, Literature Review, Ceramics, Humans, Optical Properties, Ceramic, Composite resins, Controlled Clinical Trial, Dental Bonding, Aluminum oxide, In Vitro Studies, Materials Testing, Dental Ceramics, Brittleness, and Database Search
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Research Interests: Engineering, Materials Science, Adolescent, Dental Materials, Medicine, and 15 moreAdhesive, Humans, Composite Material, Bond Strength, Middle Aged, Adult, Composite resins, Dentin, Dental Bonding, Materials Testing, Boron Compounds, Resin Cements, Molar, Medical and Health Sciences, and Methacrylates
Research Interests: Engineering, Materials Science, Dentistry, Biomedical Engineering, Treatment Outcome, and 15 moreDental Materials, Medicine, Prospective studies, Humans, Female, Male, Aged, Middle Aged, Dental Porcelain, Adult, Survival Rate, Prospective Study, Cementation, Medical and Health Sciences, and Dental restoration failure
Research Interests: Engineering, Materials Science, Dental Materials, Medicine, Adhesive, and 15 moreComposite Material, Ceramic, Bond Strength, Dental Porcelain, Composite resins, Distilled Water, Dental Stress Analysis, Dental Bonding, In Vitro Studies, Materials Testing, Composite Resin, Boron Compounds, drug storage, Dental Cements, and Medical and Health Sciences
Research Interests: Engineering, Materials Science, Computer Aided Design, Dental Materials, Medicine, and 15 moreBite force, Humans, Cement, Composite Material, Dental Porcelain, Analysis of Variance, Dental Prosthesis Design, Crowns, Dental Stress Analysis, Dental Bonding, Materials Testing, Magnesium Oxide, Cementation, Medical and Health Sciences, and Dental restoration failure
The study was designed to provide clinical outcome data for two treatments of the shortened dental arch (SDA). In a multicenter randomized controlled clinical trial, patients with complete molar loss in one jaw were provided with either a... more
The study was designed to provide clinical outcome data for two treatments of the shortened dental arch (SDA). In a multicenter randomized controlled clinical trial, patients with complete molar loss in one jaw were provided with either a partial removable dental prosthesis (PRDP) retained with precision attachments or treated according to the SDA concept preserving or restoring a premolar occlusion. No implants were placed. The primary outcome was tooth loss. Of 152 treated patients, 132 patients reached the 5-year examination. Over 5 years, 38 patients experienced tooth loss. For the primary outcome tooth loss, the Kaplan-Meier survival rates at 5 years were 0.74 (95% CI 0.64, 0.84) in the PRDP group and 0.74 (95% CI 0.63, 0.85) in the SDA group. For tooth loss in the study jaw, the survival rates at 5 years were 0.88 (95% CI 0.80, 0.95) in the PRDP group and 0.84 (95% CI 0.74, 0.93) in the SDA group. The differences were not significant. No Cox regression models of appropriate fit explaining tooth loss on the patient level could be found. The overall treatment goals of a sustainable oral rehabilitation and the avoidance of further tooth loss over longer periods were not reliably achievable. The influence of the type of prosthetic treatment on tooth loss might have been overestimated. Regarding our results, the patient's view will gain even more importance in the clinical decision between removable and fixed restorations in SDAs.
Research Interests: Dentistry, Biomedical Engineering, Medicine, Humans, Female, and 15 moreMale, Aged, Middle Aged, Premolar, Analysis of Variance, Randomized Controlled Trial, Tooth Extraction, Dental Occlusion, Dental Plaque Index, Removable Partial Denture, Proportional Hazards Models, Molar, DMF index, dental arch, and Bicuspid
The main goal of this in-vitro study was to evaluate whether tensile strength and retrievability of cemented implant-retained crowns correlate when using artificial aging. A total of 128 crowns were fabricated from a cobalt-chromium alloy... more
The main goal of this in-vitro study was to evaluate whether tensile strength and retrievability of cemented implant-retained crowns correlate when using artificial aging. A total of 128 crowns were fabricated from a cobalt-chromium alloy for 128 tapered titanium abutments (6 degrees taper, 4.3 mm diameter, 4 mm length, Camlog). The crowns were cemented with glass-ionomer (Ketac Cem, 3M) or resin cements (Multilink Implant, Telio CS Cem [Ivoclar Vivadent], Retrieve [Parkell]). Multilink Implant was used without priming. The experimental groups were subjected to either 37,500 thermal cycles between 5°C and 55°C, 1,200,000 chewing cycles, or a combination of both. Control groups were stored for 10 days in deionized water. The crowns were removed with a universal testing machine or a clinically used removal device (Coronaflex, KaVo). Data were statistically analyzed using nonparametrical tests. Retention values were recorded between 31 N and 362 N. Telio CS Cem showed the lowest retent...
Research Interests: Materials Science, Dentistry, Prosthodontics, Biomedical Engineering, Computer Aided Design, and 15 moreDental Materials, Dental Implants, Medicine, Bite force, Humans, Temperature, Implant, Time Factors, Crowns, Dental Stress Analysis, Materials Testing, Tensile Strength, Resin Cements, Retrievability, and Cementation
Research Interests: Research Design, Treatment Outcome, Germany, Prospective studies, Humans, and 14 moreFemale, Male, Mandible, Clinical Sciences, Aged, Middle Aged, Mechanical Stress, Time Factors, Trials, Dental Prosthesis Design, Dental Stress Analysis, Clinical Protocols, Cardiovascular medicine and haematology, and Dental restoration failure
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The objective of this study was to evaluate the effects of different cleaning and conditioning procedures after contamination on the tensile bond strength (TBS) of a luting resin to a core build-up composite resin. Specimens (n = 384)... more
The objective of this study was to evaluate the effects of different cleaning and conditioning procedures after contamination on the tensile bond strength (TBS) of a luting resin to a core build-up composite resin. Specimens (n = 384) made of a core build-up material were stored for 3 weeks in 37 °C water. Half of the specimens were contaminated with saliva and a disclosing silicone and then cleaned either using phosphoric acid, a pumice suspension, air-abrasion with alumina or polishing powder. Surface conditioning was performed by either using a dentin adhesive, a silane containing primer or a composite resin primer, which resulted in 24 unique combinations of 16 specimens per group. Before measuring TBS, half of the specimens of each group were stored in 37 °C water for 3d or were artificially aged for 150 days. Results show that cleaning with pumice or air-abrasion are superior methods compared to using a polishing powder or phosphoric acid. Silane is an inferior conditioning ag...