Influence of proximal box elevation technique on marginal integrity of adhesively luted Cerec inlays.

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.

In vitro performance of two-piece zirconia implant systems for anterior application.

Objectives: To investigate the influence of the implant-abutment connection on the long-term in vitro performance and fracture resistance of two-piece zirconia implant systems for anterior application.

Methods: Six groups of two-piece zirconia implant systems (n=10/group) with screw-retained (5×) or bonded (1×) connections were restored with full-contour zirconia crowns. A two-piece screw-retained titanium system served as reference.

The clinical performance of porcelain-fused-to-metal precious alloy single crowns: chipping, recurrent caries, periodontitis, and loss of retention.

Purpose: This retrospective study investigated the frequency and time history of chipping and facing failures, recurrent caries (RC), periodontitis (PE), and loss of retention (LR) of porcelain-fused-to-metal (PFM) single crowns.

Materials And Methods: A total of 997 PFM single crowns had been inserted according to a standardized treatment protocol from January 1984 to May 2009. The frequency and time history of chipping and facing failures were evaluated, as were possible risk factors from historical clinical data.

Influence of substructure design, veneer application technique, and firing regime on the in vitro performance of molar zirconia crowns.

Objectives: The aim of this in vitro study was to evaluate the influence of substructure design, veneer application technique, and firing regime on the failure and fracture resistance of molar zirconia crowns.

Methods: Six groups (n=8/group) of zirconia crowns were fabricated in simple core (SC) or anatomically reduced (AR) design, veneered with different feldspathic or glass ceramic materials, and defined according to the application technique and firing regime (LT: layering technique; LT_L: LT with long-term cooling; PT: press technique; DV: digital veneering technique). The following groups were investigated: SCLT, ARLT, SCLT_L, SCPT, ARPT, ARDV.

Wear performance of monolithic dental ceramics with different surface treatments.

Objective: To investigate the two-body wear performance of monolithic dental ceramics with different surface treatments.

Method And Materials: Standardized specimens (n = 8/ series) were fabricated from three monolithic dental ceramics (experimental translucent zirconia, experimental shaded zirconia, lithium disilicate). Four groups of each material were defined according to clinically relevant surface treatments: polished, polishedground, polished-ground-repolished, glazed.

In vitro failure and fracture resistance of veneered and full-contour zirconia restorations.

Objectives: This study evaluated the failure and fracture resistance of zirconia-based fixed partial dentures (FPDs) under the influence of different surface treatments and adjustment procedures.

Methods: Seven groups (n=8/group) of three-unit zirconia-based FPDs were fabricated in anatomic design (AD) or anatomically reduced design (ARD) and surfaces were prepared according to clinical relevance: #1: AD - sintered; #2: AD - sintered - glazed; #3: AD - sintered - sandblasted - glazed; #4: AD - sintered - polished - grinded (contact points adjusted); #5: AD - sintered - polished - grinded - repolished; #6: ARD - sintered - veneered; #7: control: analogous to #3 but without thermal cycling (TC) and mechanical loading (ML). FPDs were adhesively bonded to polymethylmethacrylate abutment teeth.

Wear performance of dental ceramics after grinding and polishing treatments.

Aim: The aim of this in vitro study was to determine the two-body wear resistance of different dental ceramics after grinding and polishing treatments.

Material And Methods: Standardized specimens were prepared from three zirconia and two veneering ceramics and were subjected to different surface treatments. Zirconia ceramics were polished, ground and repolished, veneering ceramics were ground and repolished.

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.

Glass ionomer layer thickness and its influence on zirconia failure.

Objectives: To investigate the influence of glass ionomer cement layers with various thickness and cement contamination on the fracture resistance of thin zirconia plates luted onto coplanar human molars.

Materials And Methods: Zirconia plates measuring 0.7 mm in thickness were luted onto 70 coplanarly trimmed human molars with glass ionomer cement.

Streptococcus mutans and Streptococcus sobrinus biofilm formation and metabolic activity on dental materials.

Objectives: To examine potential correlations between streptococcal biofilm formation and lactate production in streptococcal biofilms formed on the surface of dental materials with different surface characteristics.

Materials And Methods: Samples of a glass-ionomer cement (Ketac Molar) and a ceramic (Empress 2) were incubated with whole saliva and suspensions of Streptococcus mutans ATCC 25175 or Streptococcus sobrinus ATCC 33478 for initiating single-species biofilm formation for either 4 or 24 h. The relative amount of adherent, viable cells was determined using a Resazurin and a MTT assay.

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.

Candida albicans biofilm formation on soft denture liners and efficacy of cleaning protocols.

Objective: The aim of this study was to investigate Candida albicans biofilm formation on denture liners and to analyse the efficacy of cleaning protocols.

Material And Methods: Specimens were prepared from four silicone-based soft denture liners. After artificial ageing and surface free energy determination, specimens were incubated with saliva (2 h) and Candida albicans ATCC 10231 for either short- (2.

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.

Fracture resistance of zirconia FPDs with adhesive bonding versus conventional cementation.

This study investigated the fracture resistance of three different zirconia fixed partial dentures (FPDs) with different cementation methods. Forty-eight three-unit FPDs were adhesively bonded (AB) or conventionally cemented (CC). Sixteen glass-infiltrated zirconia FPDs were used as a control.

Analysis of marginal adaptation and sealing to enamel and dentin of four self-adhesive resin cements.

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.

Two-body wear of dental restorative materials.

Aim: The aim of this in vitro study was to determine the two-body wear resistance of modern direct dental restorative materials.

Methods: Eight standardized specimens were prepared from 14 dental restorative materials (nano-, micro-, hybrid-, macrofilled composites; compomer, silorane, ormocer); a veneering composite (Sinfony) and enamel were used for reference. Vickers hardness (HV) and inorganic filler weight were determined.

Influence of water sorption of the underlying abutment on fracture resistance of zirconia copings.

Objective: To investigate the influences of abutment water sorption and various aging parameters on the fracture resistance of zirconia copings.

Methods: Using a master die, identical replicas were made from three resin materials. The first was a melamine resin with very high water sorption (n = 48), the second an experimental resin core build-up composite with moderate water sorption (n = 40) and the third a commercially available core build-up composite with low water sorption (n = 40).

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.

Analysis of veneer failure of removable prosthodontics.

Objective: This retrospective study aimed to analyse the failure rate of the facings of double crown-retained dentures.

Materials And Methods: The clinical reports of 575 patients, who received double crown-retained removable dentures with a total of 1807 double crowns between 1984 and 2007, were included in the study. The 575 prostheses were attached to telescopic crowns using a friction fit (FF; n = 1999), conical crowns (CC; n = 61), or parallel-sided telescopic crowns with a clearance fit (CF; n = 315).

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 complete dentures: a retrospective study.

Purpose: Denture survival, or the time between the date of a denture's insertion and the date of its renewal for any clinical reason, was assessed in this retrospective study on 353 complete dentures. The procedures required to prolong the useful time of the study sample-relines, repair of denture base fractures, or replacement of lost artificial teeth-were also evaluated.

Materials And Methods: All dentures were examined by the authors and were constructed according to a standardized protocol by full-time staff members of the Department of Prosthodontics, Regensburg University Medical Center, between 1984 and 2009.

Investigation of mechanical properties of modern dental composites after artificial aging for one year.

This in vitro study investigated the aging behavior of dental composites with regard to surface roughness (SR), Vickers hardness (VH) and flexural strength (FS), and the study elucidated the impact of artificial aging parameters. One hundred and sixty-five rectangular specimens were prepared from five composites (Filtek Supreme XT, Filtek Silorane, CeramX, Quixfil, experimental ormocer) and subjected to various artificial aging protocols (storage in distilled water/ethanol/artificial saliva for 7, 90 and 365 days; thermal cycling, 2 x 3000 cycles 5/55 degrees C). SR, VH and FS were determined at baseline and after each aging treatment.