Dimensional stability of contemporary irreversible hydrocolloids: humidor versus wet tissue storage.

Statement Of Problem: The storage time and conditions of irreversible hydrocolloid impressions affect their accuracy and in turn the precision of the definitive cast. Recommendations for proper storage are, however, based on theoretical assumptions rather than facts.

Purpose: The purpose of this study was to assess the influence of the 2 most common storage conditions on the dimensional stability of 7 contemporary irreversible hydrocolloids (IH) for a period of up to 7 days.

Biofilm inhibition by an experimental dental resin composite containing octenidine dihydrochloride.

Objectives: The aim of the present study was to investigate an antimicrobial additive containing experimental resin composite with regards to its impact on biofilm formation under oral conditions.

Methods: Biofilms were established in situ on composite specimens (n=192) which contained octenidine dihydrochloride (ODH, 3 wt.% or 6 wt.

Bonding of acrylic denture teeth to MMA/PMMA and light-curing denture base materials: the role of conditioning liquids.

Objectives: The connection between resin denture teeth and the denture base is essential for the integrity of partial and full dentures. The aim of the present study was to analyse the bond strength of acrylic denture teeth to two light curing denture base materials compared to the gold-standard (MMA/PMMA) using different conditioning liquids.

Methods: The ridge laps of 220 identical denture teeth were ground and pre-treated using different conditioning liquids (MMA, an experimental conditioning liquid as well as the two commercially available liquids Palabond and Versyo.

Comparative evaluation of mechanical characteristics of nanofiller containing resin composites.

Purpose: To determine basic mechanical characteristics of six commercially available nanofiller containing resin composites compared to a microhybrid and a microfilled reference material. The tested hypothesis was that there are no differences in mechanical properties between the materials.

Methods: Durafill VS (DUR) and Filtek Z250 (Z250) were used as microfilled and microhybrid references.

Fracture strength of temporary fixed partial dentures: CAD/CAM versus directly fabricated restorations.

Objectives: This study aimed at investigating the influence of fabrication method, storage condition and material on the fracture strength of temporary 3-unit fixed partial dentures (FPDs).

Methods: A CrCo-alloy master model with a 3-unit FPD (abutment teeth 25 and 27) was manufactured. The master model was scanned and the data set transferred to a CAD/CAM unit (Cercon Brain Expert, Degudent, Hanau, Germany).

Factors influencing marginal cavity adaptation of nanofiller containing resin composite restorations.

Objectives: The aim of this study was to investigate the effects of polymerization contraction, shrinkage stress and Young's modulus of nanofiller containing resin composites on early marginal adaptation of restorations in cavities.

Methods: Six nanofiller containing and two reference resin composites were studied. Marginal gap widths of restorations in cylindrical 4.

Temperature rise on dentin caused by temporary crown and fixed partial denture materials: influencing factors.

Objectives: Temporary crowns and fixed partial denture materials (t-c&b) generate exothermic heat during polymerization. The amount of temperature, reaching the pulp chamber, is dependent on the residual thickness of the prepared dentin as well as the volume of the t-c&b used. Hence, the aim of this study was to investigate the influence of both factors on the temperature rise at the pulpal dentin surface as well as in the bulk of the t-c&b during polymerization.

Influence of prolonged setting time on permanent deformation of elastomeric impression materials.

Statement Of Problem: Upon removal, tear forces occur in various areas of an impression. As a result, thin sulcus details may be permanently deformed, affecting the impression's accuracy.

Purpose: The purpose of this study was to investigate the effect of the chemistry and prolonged setting time on the permanent deformation of light-body impression materials after stretching.

Contact angles of contemporary type 3 impression materials.

The aim of this study was to investigate the contact angles of six different type 3 dental impression materials (DIMs). Contact angles (n = 3) were continuously determined for 20 seconds after placing 4 MuL of deionized water onto a thin layer (50 Mum) of freshly mixed DIM (polyvinyl siloxane, C-silicone, polyether, and hybrid DIMs). Data were subjected to parametric statistics (P < .

Accuracy of impressions obtained with dual-arch trays.

This study aimed to analyze the accuracy resulting from dual-arch impressions when compared to conventional impressions in complex preparations (ie, inlay and partial crown). One hundred eighty impressions were made using two different dual-arch trays; conventional trays served as the control. The accuracy of the dies obtained (Fuji-Rock EP, GC Europe) was assessed indirectly from the change of 59 transversal dimensions.

Fracture toughness of cross-linked and non-cross-linked temporary crown and fixed partial denture materials.

Objectives: Temporary crowns and fixed partial dentures are exposed to considerable functional loading, which places severe demands on the biomaterials used for their fabrication (= temporary crown & bridge materials, t-c&b). As the longevity of biopolymers is influenced by the ability to withstand a crack propagation, the aim of this study was to investigate the fracture toughness of cross-linked and non-cross-linked t-c&bs.

Methods: Four different t-c&bs (Luxatemp AM Plus, Protemp 3 Garant, Structur Premium, Trim) were used to fabricate bar shaped specimens (2mmx5mmx25mm, ISO 13586).

Dental impact on daily living of telescopic crown-retained partial dentures.

This study aimed to analyze changes in Dental Impact on Daily Living (DIDL) scores in patients who had no prosthesis, a nonfunctioning prosthesis, or an acrylic resin prosthesis after providing them with a telescopic crown-retained partial denture. DIDL scores were recorded in 98 patients prior to and 6 to 24 months after treatment. All DIDL scores (overall and dimension scores) increased significantly after treatment.

Correlation between polymerization shrinkage and marginal fit of temporary crowns.

Objectives: During polymerization, temporary c&b materials (t-c&b) undergo shrinkage which may lead to marginal inaccuracies of the temporary restoration. The degree of correlation between these two factors is still unknown. Hence, the objective of this study was to determine the polymerization shrinkage of t-c&bs and to evaluate, to which degree the shrinkage is correlated to the width of the marginal gap.

Changes in occlusal force at denture dislodgement after refabrication or optimization of complete dentures.

The aim of this study was to evaluate the change in occlusal force at denture dislodgement (OFD) in patients with poorly fitting complete dentures after improvement. In 91 patients, OFD was recorded before treatment, immediately after fitting the renewed denture (direct effect), and 1 week, 1 month, and 6 months later (adaptation). OFD increased significantly (P < .

Influence of impression technique and material on the accuracy of multiple implant impressions.

This study aimed to analyze the influence of impression technique (pick-up versus reposition) and material on the accuracy of the working cast. Sixty impressions were made with 3 materials from a master cast with 4 XiVE implants. The changes in the implant axis direction, rotation, and 3-dimensional shift were assessed.

Effect of surface condition and storage time on the repairability of temporary crown and fixed partial denture materials.

Objectives: The aim of the present study was to investigate which parameters (chemical nature, time after mixing, surface characteristics) might affect the repair strength of temporary crown and bridge materials (t-c&b).

Methods: Four different t-c&bs (Cool Temp Natural, Protemp 3 Garant, Structur Premium, Trim) were investigated using a shear-bond strength (SBS) setup. A cylinder (2 mm x 2.

Influence of denture improvement on the nutritional status and quality of life of geriatric patients.

Unlabelled: Recent research suggests that there is a correlation between nutrition, oral health, dietary habits, patients' satisfaction and their socio-economic status. However, the dependent and independent variables have remained unclear.

Objective: This exploratory interventional study aimed to identify the impact of denture improvement on the nutritional status as well as the oral health-related quality of life in geriatric patients.

Influence of different retraction techniques on crevicular fluid flow.

This study aimed to analyze the influence of different retraction techniques (pure cotton cord, cord impregnated with epinephrine, and chemical retraction [Expa-syl]) on the crevicular fluid flow in vivo. A total of 340 prepared teeth were randomly assigned to one of the retraction procedures. Crevicular fluid flow was measured prior to and immediately after the removal of the respective retraction material.

Effect of different retraction and impression techniques on the marginal fit of crowns.

Objectives: Periodontal conditions in restored teeth are strongly influenced by the marginal fit of the restoration which is closely related to the quality of the impression. However, the influence of the retraction and impression technique on the outcome of the impression has only sparsely been investigated. Thus, it was the objective of this study to compare the marginal fit in fixed restorations using two modes of gingival retraction and two different impression techniques in an animal model.

Influence of the occlusal concept of complete dentures on patient satisfaction in the initial phase after fitting: bilateral balanced occlusion vs canine guidance.

This clinical single-blind study aimed to evaluate the influence of 2 occlusal concepts (OCs) on patient satisfaction in the initial phaseafter fitting new complete dentures (CDs). Thirty-eight edentulous patients received 1 new maxillary CD and 2 almost identical mandibular CDs, which differed only in their OC (bilateral balanced occlusion vs canine guidance). After 2 weeks, the patients' satisfaction was evaluated and the OC was changed.

Working time of elastomeric impression materials: relevance of rheological tests.

Purpose: To study possible relationships between rheological parameters of elastomeric impression materials and their dimensional accuracy at different stages during setting within the manufacturers' recommended working time.

Methods: Four chemically different impression material-types were tested. Impressions were taken of a master cone at 30-second intervals after mixing and up to 30 seconds beyond the recommended working time.

Dimensional accuracy of 2-stage putty-wash impressions: influence of impression trays and viscosity.

The aim of this in vitro study was to evaluate the influence of the impression tray and viscosity of the wash material on the dimensional accuracy of impressions taken using a 2-stage putty-wash technique. Identically shaped metal stock trays (MeTs) and disposable plastic stock trays (DiTs) were used for taking impressions (n = 10) of a mandibular cast (4 abutments) with 2 different impression materials. Dies were poured and the relative diameter deviation was calculated after measurement.

Mechanical properties of provisional crown and bridge materials: chemical-curing versus dual-curing systems.

Objectives: This study aimed to investigate the flexural strength (FS) and flexural modulus (FM) of provisional crown and bridge materials at different storage times after mixing using materials with different curing mechanisms (dual-curing vs. self-curing).

Methods: FS and FM of four proprietary materials (Trim, Luxatemp AM Plus, Luxatemp AM Plus Solar and Cool Temp Natural) were tested in a 3-point bending test according to EN ISO 4049:2000 at various times after mixing (37 degrees C dry/water) including thermocycling (5000x, 5-55 degrees C).

Long-term analysis of telescopic crown retained removable partial dentures: survival and need for maintenance.

Objectives: The aim of this retrospective longitudinal study was to evaluate the clinical long-term survival of telescopic crown retained removable partial dentures (TRPDs), the influencing factors on survival as well as the type and number of necessary treatments during the observation time.

Methods: The study is based on the data of 463 patients who had received a total of 554 TRPDs with a total of 1758 telescopic crowns between 1995 and 2004 in our Dental School. The influence of the patient's gender, location of the denture, number of abutment teeth per telescopic denture, their distribution (Kennedy-class) and the impact of a routinely follow-up programme on the survival probability were analysed.

Influence of solvent type in experimental dentin primer on the marginal adaptation of Class V restorations.

Objectives: The purpose of this in vitro investigation was to evaluate the influence of the solvent type in two experimental dentin primers (ExP) on the handling sensitivity by determining the marginal adaptation of mixed Class V restorations.

Methods: Standardized cavities were prepared in 32 extracted human molars and randomly assigned to four test groups (n=8). After etching, a three-step adhesive was applied using two ExP which only differed in the type of solvent (acetone/water=ExP-A versus ethanol/water=ExP-E).