Significance of site-specific radiation dose and technique for success of implant-based prosthetic rehabilitation in irradiated head and neck cancer patients-A cohort study.

Background: Radiotherapy aggravates implant-based prosthetic rehabilitation in patients with head and neck cancer.

Purpose: To evaluate the impact of radiation dose at implant and parotid gland site for prosthetic rehabilitation.

Material And Methods: The retrospective study includes 121 irradiated head and neck cancer patients with 751 inserted implants.

Implant survival or implant success? Evaluation of implant-based prosthetic rehabilitation in head and neck cancer patients-a prospective observational study.

Objectives: Definition of implant success is unclear in prosthetic implant-based rehabilitation of head neck cancer patients.

Materials And Methods: Fifty-two patients with 309 inserted implants were included in this prospective observational study. Implant survival (in situ and loaded) and implant success (modified Albrektsson criteria) at 2-year follow-up were evaluated under the influence of patient- and implant-specific variables.

Validating laboratory simulation with resin-based materials for temporary fixed denture prostheses - Results from clinical and laboratory trials.

The aim of the current study was to relate an artificial aging protocol for the analysis of dental materials to their clinical performance. 20 fixed interim restorations (crowns and fixed denture prostheses (FDPs)) fabricated from two commercially available resin-based composites (RBCs) and a previous clinical trial served as templates for the fabrication of duplicate restorations. Duplicates were subjected to artificial aging using thermal cycling and mechanical loading.

Performance of resin materials for temporary fixed denture prostheses.

This study investigated the handling properties and clinical performance of two commercially available resin materials with slight differences in filler composition for the fabrication of fixed interim restorations. In a dental university setting, patients requiring prosthetic treatment were supplied with fixed interim restorations fabricated from two commercially available resin materials. To clarify the handling properties of the resin materials, dentists and undergraduate students completed a questionnaire.

Shear bond strength between veneering composite and PEEK after different surface modifications.

Objectives: This study aims to test the influence of different surface treatments and conditioning on the shear bond strength between polyetherketone (PEEK) and composite.

Materials And Methods: Surfaces (570 plates) were used untreated, etched, air-particle abraded or activated with silica-modified alumina oxide. Surface roughness was determined after different treatments.

Effect of tooth brush abrasion and thermo-mechanical loading on direct and indirect veneer restorations.

Objectives: This study investigated toothbrush abrasion and in vitro aging on ceramic (indirect technique) and composite veneers (direct technique).

Materials And Methods: Identical composite and individual human incisors were restored with industrially preformed composite veneers, indirectly produced ceramic veneers, and direct composite restorations. Surface roughness was determined before and after tooth brushing.

Influence of cusp inclination and curvature on the in vitro failure and fracture resistance of veneered zirconia crowns.

Objectives: The aim was to investigate the influence of cusp inclinations and curvatures on the failure behaviour and fracture resistance of veneered zirconia crowns.

Materials And Methods: Five groups (n = 8/group) of zirconia-based molar crowns were fabricated by modifying cusp inclination (S, steep = 45°; M, medium = 30°; F, flat = 10°) and curvature (P, pointed; R, round; O, round-oblate). Combinations MP, MR, SP, SR and FO were investigated.

Clinical performance of cast clasp-retained removable partial dentures: a retrospective study.

Purpose: This retrospective study investigated the survival rate of 174 clasp-retained removable partial dentures (CR-RPDs) made at the Department of Prosthodontics of the Regensburg University Medical Center over a 25-year period (1984 to 2009).

Materials And Methods: The study analyzed the frequency of and time to the fracture of clasps, connectors, or denture bases; the occurrence of caries or periodontal lesions; the loss of abutment teeth; and the necessity of maintenance procedures such as relining or treatment of pressure areas.

Results: The median follow-up time of 3 years was calculated using the inverse Kaplan-Meier method.

The two main theories on dental bruxism.

Bruxism is characterized by non-functional contact of mandibular and maxillary teeth resulting in clenching or grating of teeth. Theories on factors causing bruxism are a matter of controversy in current literature. The dental profession has predominantly viewed peripheral local morphological disorders, such as malocclusion, as the cause of clenching and gnashing.

Influence of resilient support of abutment teeth on fracture resistance of all-ceramic fixed partial dentures: an in vitro study.

Purpose: The influence of resilient support of abutment teeth on the fracture resistance of all-ceramic three-unit fixed partial dentures (FPDs) was tested in this study.

Materials And Methods: Three groups (n = 8) of glass-infiltrated, alumina-based, all-ceramic FPDs that were adhesively bonded to human molar teeth were investigated. In control group A, teeth that were rigidly inserted in polymethyl methacrylate (PMMA) resin were used for thermocycling and mechanical loading (TCML), as well as for fracture testing.

Two-body wear of dental porcelain and substructure oxide ceramics.

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.

Wear performance of substructure ceramics and veneering porcelains.

Aim: The aim of this in vitro study was to compare the two-body wear resistance of substructure zirconia and veneering porcelain versus steatite and human enamel antagonists, respectively.

Materials And Methods: Two-body wear tests were performed in a chewing simulator with steatite and enamel antagonists (enamel cusps). A pin-on-block design with a vertical load of 50 N for 1.

Bond of acrylic teeth to different denture base resins after various surface-conditioning methods.

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).

The bond strength of the resin-to-zirconia interface using different bonding concepts.

Objectives: This study investigated the shear bond strength (SBS) and the tensile bond strength (TBS) of the zirconia-to-resin interface using different cement bonding concepts.

Methods: Coplanar zirconia specimens were bonded to CoCr-cylinders measuring 5 mm in diameter and 3 mm in height. All bonding areas were first sandblasted with 110 μm Al(2)O(3) (0.

Influence of the fabrication process on the in vitro performance of fixed dental prostheses with zirconia substructures.

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.

Clinical performance of cements as luting agents for telescopic double crown-retained removable partial and complete overdentures.

Purpose: The aim of this study was to investigate the survival rates and technical failures of removable prostheses (RPs) supported by telescopic double crown (TDC)-retained abutment teeth luted with zinc-phosphate or glass-ionomer cement.

Materials And Methods: Clinical records of 577 patients (288 women, 289 men) who received 577 TDC-retained RPs supported by 1,807 abutments at the Department of Prosthodontics of the University Hospital Regensburg, Regensburg, Germany, between 1984 and 2007 were analyzed. The 577 prostheses included 200 attached to telescopic crowns with friction fit (FFs), 62 to conical crowns (CCs), and 315 to parallel-sided telescopic crowns with clearance fit (CFs).

Casting ability of selected impression materials tested in different conditions in an in vitro sulcus model.

Objective: To test casting capacities of impression materials under dry and wet sulcular conditions in vitro.

Method And Materials: An incisor with a circular shoulder preparation (1 mm) was inserted in a primary mold. A shiftable secondary mold allowed adaptation of sulcular depth (1 to 4 mm).

Influence of substructure design and spacer settings on the in vitro performance of molar zirconia crowns.

Objectives: The aim of this study was to evaluate the in vitro behaviour of all-ceramic zirconia molar crowns in regard to different core designs and marginal fit.

Methods: Identically shaped methacrylate molars were prepared according to the ceramic restoration directives resulting in a 1-mm deep circular shoulder preparation. They were embedded in polymethylmethacrylate resin after covering their roots with a polyether layer to simulate periodontal mobility.

Fracture characteristics of anterior resin-bonded zirconia-fixed partial dentures.

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.

Self-adhesive resin cement versus zinc phosphate luting material: a prospective clinical trial begun 2003.

Objectives: The literature demonstrates that conventional luting of metal-based restorations using zinc phosphate cements is clinically successful over 20 years. This study compared the clinical outcomes of metal-based fixed partial dentures luted conventionally with zinc phosphate and self-adhesive resin cement.

Methods: Forty-nine patients (mean age 54+/-13 years) received 49 metal-based fixed partial dentures randomly luted using zinc phosphate (Richter & Hoffmann, Berlin, Germany) or self-adhesive resin cement (RelyX Unicem Aplicap, 3M ESPE, Germany) at the University Medical Center Regensburg.

Zirconia resin-bonded fixed partial dentures in the anterior maxilla.

Objective: To determine the fracture resistance of resin-bonded fixed partial dentures (RBFPDs) by examining the influence of framework design and abutment mobility.

Method And Materials: RBFPD frameworks were made of zirconia (Cercon Base, Degudent) or a nonprecious alloy (reference; Dentitan, Elephant Dental) and veneered with ceramic (Cercon Ceram S, Degudent). The zirconia framework design varied between a 2-retainer RBFPD with 3 different levels of tooth mobility (groups 1 to 3) and a 1-retainer cantilever version with 2 different grades of tooth mobility (groups 4 and 5).

Approach for valuating the significance of laboratory simulation.

Objective: The aim of this investigation was to compare the clinical survival rate of all-ceramic FPDs with failures during in vitro simulation.

Methods: 40 anterior FPDs were manufactured from lithiumdisilicate ceramic and alumina-oxide ceramic. The FPDs were adhesively bonded to human teeth and artificially aged to investigate the survival rate during thermal cycling and mechanical loading (TCML(1); 3.

Fracture force of tooth-tooth- and implant-tooth-supported all-ceramic fixed partial dentures using titanium vs. customised zirconia implant abutments.

Objectives: Tooth-coloured customised implant abutments and full ceramic supraconstructions thereon can be made of zirconia by computer-aided manufacturing (CAM). The aim of this study was to examine the potential limits of zirconia three-unit fixed partial dentures made on customised zirconia implant abutments in implant-tooth supported cases.

Material And Methods: Rigidly mounted implants (XiVE-S diameter 3.

Changes of cement properties caused by mixing errors: the therapeutic range of different cement types.

Objective: The hypothesis was that low grade variations of mixing ratios of luting agents have negligible influence, while high grade variations cause severe property changes independent from the cement type used.

Material And Methods: A zinc oxide phosphate, carboxylate, glass ionomer, resin-modified glass ionomer, dual-curing composite and self-adhesive composite cement were mixed using various mixing ratios. Beside the recommended ratio, samples were mixed with ratios between 10 and 25% (low grade) up to 60% (high grade) variation of powder/liquid, respectively base/catalyst pastes.

Outcomes of temporomandibular joint disorder therapy: observations over 13 years.

Objective: To evaluate the outcome of temporomandibular joint (TMJ) disorder therapy with different kinds of splints.

Methods: One-hundred-and-twenty-nine patients with TMJ disorders and meeting the primary selection criterion of reporting pain in the TMJ region were clinically evaluated. Magnetic resonance imaging of the TMJ was performed at baseline 1993-94.