In vitro investigations on retention force behavior of conventional and modern double crown systems.

Objective: This study aimed to investigate the effects of long-term use on the retention force and wear behavior of double crown systems.

Methods: Based on a common double crown design sixty pairs of telescopic crowns were fabricated and divided into six groups, each consisting ten samples: "Gold standard" cast gold alloy primary and secondary crown (GG) and cast non-precious alloy (NN), computer-aided design (CAD)/computer-aided manufacturing (CAM)-milled zirconia primary crown and galvanoformed secondary crown (ZG), CAD/CAM-milled non-precious alloy primary and secondary crown (CC NN), CAD/CAM-milled zirconia primary crown and non-precious alloy secondary crown (CC ZN) and CAD/CAM-milled zirconia primary crown and polyetheretherketone (PEEK) secondary crown (CC ZP). In the constant presence of artificial saliva, all samples were subjected to 10,000 joining-separation cycles at a velocity of 120 mm/min.

Periodontal health in shortened dental arches: A 10-year RCT.

Purpose: This analysis focused on periodontal health in shortened dental arches (SDAs).

Methods: In a randomized controlled clinical trial, patients with missing molars in one jaw and at least one premolar and canine on both sides were eligible for participation. In the partial removable dental prosthesis (PRDP) group (n = 79), molars were replaced with a precision attachment retained PRDP.

Impact of shortened dental arch on oral health-related quality of life over a period of 10 years - A randomized controlled trial.

Objectives: To compare oral health-related quality of life (OHRQoL) in patients with either molar replacement by partial removable dental prostheses (PRDP) or with restored shortened dental arches (SDA) over a period of 10 years.

Methods: In this multi-center RCT, a consecutive sample of 215 patients with bilateral molar loss in at least one jaw was initially recruited in 14 prosthodontic departments. Of those patients, 150 could be randomly allocated to the treatment groups (SDA: n = 71; PRDP: n = 79), received the allocated treatment, and were available for follow-up assessments.

The Randomized Shortened Dental Arch Study: Tooth Loss Over 10 Years.

Purpose: This study aimed to compare the long-term outcomes of two different nonimplant treatments in the bilateral shortened dental arch (SDA).

Materials And Methods: In a multicenter randomized controlled clinical trial, patients with complete molar loss in one arch were assigned to one of two different nonimplant treatments. In the partial removable dental prosthesis (PRDP) group, patients were provided with a distal-extension prosthesis retained with precision attachments.

Suitability and accuracy of CBCT model scan: an in vitro study.

Plaster casts can be digitized with desktop scanners, intraoral scanners, and recently also with cone beam computed tomography (CBCT). The aim of this study was to investigate the accuracy of five different CBCT devices digitizing a plaster cast. A study cast serving as a patient was made using the double mix impression technique, and the impression was poured out with plaster.

Accuracy of full-arch scans using intraoral and extraoral scanners: an in vitro study using a new method of evaluation.

The aim of this study was to compare the accuracy of six intraoral scanners as regards clinically relevant distances using a new method of evaluation. An additional objective was to compare intraoral scanners with the indirect digitization of model scanners. A resin master model was created by 3D printing and drilled in five places to reflect the following distances: intermolar width (IMW), intercanine width (ICW), and arch length (AL).

The randomized shortened dental arch study: influence of two different treatments on interdental spacing over 5 years.

Objectives: Being a secondary outcome in a multicenter randomized controlled trial, the present analysis focused on interdental spacing in the shortened dental arch (SDA). The aim was to evaluate changes in interdental spacing in dependence of two different treatments after an observation period of up to 5 years.

Material And Methods: Patients were either treated with a partial removable dental prosthesis (PRDP) for molar replacement (PRDP group) or according to the SDA concept aiming at a premolar occlusion (SDA group) in a randomized manner.

Assessment formats in dental medicine: An overview.

Aim: At the annual meeting of German dentists in Frankfurt am Main in 2013, the Working Group for the Advancement of Dental Education (AKWLZ) initiated an interdisciplinary working group to address assessments in dental education. This paper presents an overview of the current work being done by this working group, some of whose members are also actively involved in the German Association for Medical Education's (GMA) working group for dental education. The aim is to present a summary of the current state of research on this topic for all those who participate in the design, administration and evaluation of university-specific assessments in dentistry.

Influence of the preparation design and artificial aging on the fracture resistance of monolithic zirconia crowns.

Purpose: The aim of this study was to evaluate the fracture resistance and fracture behavior of monolithic zirconia crowns in accordance with the preparation design and aging simulation method.

Materials And Methods: An upper first molar was prepared sequentially with three different preparation designs: shoulderless preparation, 0.4 mm chamfer and 0.

Post-endodontic treatment of incisors and premolars among dental practitioners in Saarland: an interactive Web-based survey.

Objectives: The aim of the present study was to evaluate the trend of dental practitioners in the federal state of Saarland in Germany in regard to restoring endodontically treated teeth using a Web-based survey.

Materials And Methods: An interactive Web-based survey instrument was developed, including seven clinical scenarios, presented by photographs of natural incisor and premolar with different types of cavities. Following a decision tree adapted to the clinical treatment, questions on different aspects of the post-endodontic treatment were asked.

The randomized shortened dental arch study: temporomandibular disorder pain.

Objectives: The aim of this multi-center, randomized controlled trial was to assess the impact of missing posterior support on the risk for temporomandibular disorder (TMD) pain by comparing patients with either shortened dental arches (SDA) or molar replacement by removable dental prostheses (RDP).

Methods: A sample of 215 patients with bilateral molar loss in at least one jaw was consecutively recruited in 14 prosthodontic departments of dental schools in Germany. Of the initial sample, 152 patients (mean age: 59.

Pre-fabricated zirconium dioxide implant abutments for single-tooth replacement in the posterior region: success and failure after 3 years of function.

Objective: Zirconia implant abutments have gained a much broader clinical use over the past few years. The aim of the present study was to assess the clinical performance of a pre-fabricated zirconium dioxide implant abutment for single-tooth replacement in the posterior region.

Materials And Methods: Forty implants of the XiVE(®) S plus screw type (DENTSPLY Friadent, Mannheim, Germany) were inserted in the posterior region of 24 patients and provided with zirconium dioxide abutments (FRIADENT(®) CERCON(®) Abutment, DENTSPLY Friadent).

Wear behavior of dental Y-TZP ceramic against natural enamel after different finishing procedures.

Objective: The aim of this in vitro study was to evaluate the influence of different finishing procedures on the wear behavior of zirconia against natural enamel.

Methods: 64 quadratic specimens (10 mm × 10 mm × 2 mm) were cut from a commercial hipped dental Y-TZP ceramic. Four different groups with 16 specimens each were formed according to the following finishing procedures: PZ (polished), RR (fine-grit diamond), GR (coarse-grit diamond), GZ (glazed).

In vitro investigation of the performance of different restorative materials under cast circumferential clasps for removable dental prostheses.

Objectives: The objective of this in vitro study was to investigate the behavior of different composite restorative materials under the load of cast circumferential clasps for removable dental prostheses (RDPs).

Methods: In 60 human molars, standardized mesial-occlusal-distal cavities were prepared. The cavities were restored with the following materials: Definite, Tetric Ceram, SureFil, Heliomolar RO, Ariston pHc, and Oralloy, and provided with a rest seat.

Dental care and treatment needs of elderly in nursing homes in Saarland: perceptions of the homes managers.

Objective: To investigate nursing home managers' perceptions and attitudes towards oral health care and access to dental services for aged care facility residents.

Method: Questionnaires containing 28 closed-ended questions were mailed to all 114 nursing homes in Saarland, Germany. Descriptive statistics were calculated for response items.

Clinical success rates for polyether crown impressions when mixed dynamically and statically.

The purpose of this study is to compare success rates of dual-viscosity impressions for two types of mixing techniques of the polyether elastomeric impression material. Additionally, influencing parameters on the success rates should be evaluated. The expectation was that there would be no difference between the success rates for the two mixing techniques.

Subcritical crack growth behavior and life data analysis of two types of dental Y-TZP ceramics.

Objectives: The aim of this study was to evaluate the mechanical properties and the subcritical crack growth behavior of a presintered dental Y-TZP (Kavo Everest ZS) and a hot isostatic pressed Y-TZP (Kavo Everest ZH) and to perform life data analysis.

Methods: For each material 150 bending bars were produced. The initial fracture strength was determined in a four-point bending test.

Influence of fatigue testing and cementation mode on the load-bearing capability of bovine incisors restored with crowns and FRC posts.

The aim of the study was to evaluate the influence of fatigue and cementation mode on the fracture behaviour of endodontically treated bovine incisors restored with fiber-reinforced-composite (FRC) posts and crowns. Forty-eight endodontically treated incisors were restored with FRC posts, composite build-ups, and cast crowns. In 16 teeth, each of the posts were cemented conventionally with KetacCem (3M Espe) or adhesively with Panavia F (Kuraray) or RelyXUniCem (3M Espe).

Introducing and evaluating MorphoDent, a Web-based learning program in dental morphology.

MorphoDent, a computer-assisted learning program designed to teach the anatomy of the adult dentition, was introduced into the curriculum of dentistry at the University of Saarland in Homburg, Germany. Thirty-six second-year students of the School of Dentistry were introduced to morphoDent alongside the traditional lectures of dental anatomy. Questionnaires that evaluated the students' perceptions of virtual learning as well as aspects of the functionality of the program educational objectives were developed and distributed to the students.

Influence of artificial aging on the load-bearing capability of straight or angulated zirconia abutments in implant/tooth-supported fixed partial dentures.

Purpose: The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated zirconia implant abutments used in ZirDesign (Astra Tech) implant/tooth-supported fixed partial dentures (FPDs) in the maxilla.

Materials And Methods: Four different test groups (n = 8) representing anterior implant/tooth-supported FPDs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position (maxillary left central incisor) from a prosthetic point of view, which allowed for the use of a straight, prefabricated zirconia abutment.

Prefabricated zirconium dioxide implant abutments for single-tooth replacement in the posterior region: evaluation of peri-implant tissues and superstructures after 12 months of function.

Aim: In the present study, prefabricated abutments made of zirconium dioxide Y-TZP (tetragonal zirconia polycrystals) were inserted into the posterior region under controlled clinical conditions. The aim was to test whether abutments made of zirconium dioxide are suitable for this indication. Investigation parameters included reactions of peri-implant tissue and the structural integrity of the all-ceramic superstructures on the implants.

The Randomized Shortened Dental Arch study (RaSDA): design and protocol.

Background: Various treatment options for the prosthetic treatment of jaws where all molars are lost are under discussion. Besides the placement of implants, two main treatment types can be distinguished: replacement of the missing molars with removable dental prostheses and non-replacement of the molars, i.e.

Fracture behavior of straight or angulated zirconia implant abutments supporting anterior single crowns.

The aim of the study was to evaluate the influence of artificial aging on the fracture behavior of straight and angulated zirconia implant abutments (ZirDesign™; Astra Tech, Mölndal, Sweden) supporting anterior single crowns (SCs). Four different test groups (n = 8) representing anterior SCs were prepared. Groups 1 and 2 simulated a clinical situation with an ideal implant position (left central incisor) from a prosthetic point of view, which allows for the use of a straight, prefabricated zirconia abutment.

Fracture behaviour of implant-implant- and implant-tooth-supported all-ceramic fixed dental prostheses utilising zirconium dioxide implant abutments.

This in vitro study investigated the fracture behaviour of implant-implant-supported and implant-tooth-supported all-ceramic fixed dental prostheses (FDP) using zirconium dioxide implant abutments (FRIADENT® CERCON® abutments, DENTSPLY Friadent). Six different test groups (n = 8) were prepared. Groups 1, 2, 4, and 5 represented an implant-implant-supported FDP condition, whereas groups 3 and 6 simulated an implant-tooth-supported FDP condition.

Zirconium dioxide implant abutments for posterior single-tooth replacement: first results.

Background: Prefabricated implant abutments made of zirconium dioxide (yttria-stabilized polycrystalline tetragonal zirconia; Y-TZP) have proved to be useful in the esthetically demanding anterior region and may also be useful for premolar and molar replacement because of their obvious positive impact on the health of peri-implant soft tissues.

Methods: Forty screw implants were inserted in the posterior region of 24 patients and provided with prefabricated all-ceramic abutments made of zirconium dioxide Y-TZP. Zirconia-based crowns were used as superstructures.