bluuebunny/crossref_metadata_2025_split huggingface dataset:
Event‐related potentials during mental imagery of animal sounds
Authors: Wu Jianhui , Mai Xiaoqin , Chan Chetwyn C.H. , Zheng Yaqin , Luo Yuejia 
Published: October 2006

AbstractTo investigate the neural correlates of imagined animal sounds, event‐related potentials (ERPs) were recorded while subjects were presented with (1) animal pictures without any imagery instruction (control) or (2) animal pictures with instructions to imagine the corresponding sounds (imagery). The results revealed imagery effects starting with an enhancement of the P2, possibly indexing the top‐down allocation of attention to the imagery task, and continuing into a more positive‐going deflection in the time window of 350–600 ms poststimulus, probably reflecting the formation of auditory imagery. A centro‐parietally distributed late positive complex (LPC) was identified in the difference waveform (imagery minus control) and might reflect two subprocesses of imagery formation: sound retrieval from stored information and representation in working memory.
Comparison of the effectiveness of a nitrification inhibitor, dicyandiamide, in reducing nitrous oxide emissions in four different soils under different climatic and management conditions
Authors: Di H. J. , Cameron K. C. , Sherlock R. R. 
Published: October 2006

AbstractNitrous oxide (N2O) is a potent greenhouse gas and, in New Zealand, about one‐third of the total greenhouse gas emissions from the agricultural sector are of N2O, mostly derived from animal excreta in grazed pasture soils. The aim of this study was to determine the effectiveness of a nitrification inhibitor, dicyandiamide (DCD), in reducing N2O emissions from animal urine patches in four different soils located in different regions of New Zealand with different soil, climatic and management conditions. The four soils are Templeton fine sandy loam and Lismore stony silt loam in Canterbury in the South Island, Horotiu silt loam in the Waikato region and Taupo pumice sand near Lake Taupo, both in the North Island. Results showed that the application of a fine‐particle suspension nitrification inhibitor, DCD, to grazed pasture soils was very effective in reducing N2O emissions in all four different soils. Total N2O emissions (over 69–137 days) from animal urine patches ranged from 1 to 20.9 kg N2O‐N ha−1 without DCD. These were reduced to 0.31–5.7 kg N2O‐N ha−1 by the use of DCD, representing 61–73% reductions (with an average of 70% reduction). The N2O‐N emission factor from animal urine N, EF3, was reduced from an average of 0.9 to 0.3% by the use of DCD. These results demonstrate the potential of using nitrification inhibitors to mitigate N2O emissions in a wide range of grazed pasture soils under different climatic and management conditions.
Response of soil exchangeable and crop potassium concentrations to variable fertilizer and cropping regimes in long‐term field experiments on different soil types
Authors: Andersson S. , Simonsson M. , Mattsson L. , Edwards A. C. , ÖBorn I. 
Published: October 2006

AbstractAnnual potassium (K) balances have been calculated over a 40‐year period for five field experiments located on varying parent materials (from loamy sand to clay) in south and central Sweden. Each experiment consisted of a number of K fertilizer regimes and was divided into two crop rotations, mixed arable/livestock (I) and arable only (II). Annual calculations were based on data for K inputs through manure and fertilizer, and outputs in crop removal. Plots receiving no K fertilizer showed negative K balances which ranged from 30 to 65 kg ha−1 year−1 in rotation I, compared with 10–26 kg ha−1 year−1 for rotation II. On sandy loam and clay soils, the K yield of nil K plots (rotation I) increased significantly with time during the experimental period indicating increasing release of K from soil minerals, uptake from deeper soil horizons and/or depletion of exchangeable soil K (Kex). Significant depletion of Kex in the topsoil was only found in the loamy sand indicating a K supply from internal sources in the sandy loam and clay soils. On silty clay and clay soils, a grass/clover ley K concentration of ∼2% (dry weight) was maintained during the 40‐year study period on the nil K plots, but on the sandy loam, loam and loamy sand, herbage concentrations were generally less than 2% K.
Subjective Need for Implant Treatment among Middle‐aged People in Sweden and Denmark
Authors: Kronström Mats , Palmqvist Sigvard , Söderfeldt Björn , Vigild Merete 
Published: October 2006

ABSTRACT Background: The use of oral implants in prosthodontics has become widespread and regarded as a predictable treatment modality. However, there is a lack of knowledge among the general population about the prevalence and need for implant treatments. Purpose: This study was undertaken to register and compare the prevalence of dental implants and the subjective need for implant treatment among people in Sweden and Denmark. Materials and Methods: Random samples taken from the national population registers in Sweden and Denmark comprised 1001 Swedish subjects aged 55 to 79 years and 1175 Danish subjects aged 45 to 69 years. Subjects were requested to fill out questionnaires regarding dental conditions, subjective need for implant treatment, whether they had received treatment with dental implants during the previous 10 years, and so on. Results: Of the Swedes, 4.8% reported that they had dental implants, compared with 2.5% of the Danes. In the Swedish sample, age was significantly associated with subjective need for implant treatment. In the Danish sample, women showed a significantly higher subjective need for implant treatment than did men. Conclusions: Compared with the Swedish sample, the subjective need for treatment with dental implants was higher in the Danish sample, although the patient fees were substantially higher in Denmark.
Enhanced Periodontal Response and Esthetics of Implant‐Supported Bridge by the Use of Galvanoforming Technique: Case Report
Authors: Tietmann Christina , Broseler Frank 
Published: October 2006

ABSTRACT Background: Galvanoforming restorations have been placed over the past 15 years successfully. They offer several advantages over alloy restorations, including enhanced response to the periodontal tissues, biocompatibility, and superior esthetics. Purpose: The purpose of this report is to show the use of the galvanoforming process in dental implant restorations to transfer the benefits of this technique. Materials and Methods: Two standard Branemark fixtures were placed submerged in the lower mandible for the restoration of a three‐unit bridge. The impression was taken at fixture level, and two cast individual telescope abutments were inserted. The galvanoforming restoration was seated conventionally without any screw retention. Results: An implant‐supported galvanoforming bridge is functioning successfully. The use of biocompatible materials does not compromise the stability of the restoration; instead, the effect on the periodontal tissues is excellent, resulting in less plaque accumulation and bleeding on probing. Microgaps were avoided by conventional seating on the individual telescope gold abutments, revealing superior occlusal esthetics. Conclusions: This case report demonstrates the practicability of the biocompatible galvanoforming procedure for implant‐supported restorations enhancing periodontal response and esthetics.
Clinical Experience of CNC‐Milled Titanium Frameworks Supported by Implants in the Edentulous Jaw: A 3‐Year Interim Report
Authors: Örtorp Anders , Jemt Torsten 
Published: October 2006

ABSTRACT Background: The use of computer numeric controlled (CNC)‐milled titanium frameworks is a new technique for framework fabrication, and few clinical reports have been made on this treatment modality. Purpose: The goal of this study was to report the clinical performance of implant‐supported prostheses with CNC‐milled titanium frameworks in the edentulous jaw and to compare the results with prostheses provided with conventional cast frameworks during the first 3 years of function. Materials and Methods: A consecutive group of 126 edentulous patients were provided by random distribution with 67 prostheses with CNC‐milled titanium frameworks in 23 upper and 44 lower jaws and 62 conventional prostheses with gold‐alloy castings in 31 upper and 31 lower jaws. Radiographic 1‐year data and clinical 3‐year data were collected for both the titanium and control group. Results: One prosthesis was lost in each group owing to loss of implants, and the overall 3‐year prosthesis cumulative survival rate was 98.2% for both groups. Patients with smoking habits experienced significantly more implant failures than nonsmokers (p =.006). Few problems were observed. No metal fractures were seen in the test group, whereas two frameworks and one abutment screw fractured in the control group. Resin veneer fractures were the most common complication, with a slightly higher incidence observed in the control group. Conclusions: Computer numeric controlled‐milled titanium frameworks can be used as an alternative to conventional castings in the edentulous jaw, presenting clinical performance similar to that of conventional cast frameworks during the first 3 years of function.
Early Loading of Maxillary Fixed Cross‐Arch Dental Prostheses Supported by Six or Eight Oxidized Titanium Implants: Results after 1 Year of Loading, Case Series
Authors: Olsson Morgan , Urde Göran , Andersen Jan B. , Sennerby Lars 
Published: October 2006

ABSTRACTBackground:Recent reports have demonstrated that immediate/early loading of dental implants is a clinically feasible concept with results similar to those for two‐stage procedures, at least in good bone qualities. However, documentation of the outcome of immediate/early loading in the totally edentulous maxilla is scarce.Purpose:The present investigation was undertaken to evaluate the outcome over 1 year of oxidized titanium implants when loaded with a fixed full‐arch bridge in the maxilla 1 to 9 days after implant placement.Materials and Methods:Ten patients with totally edentulous maxillas were treated with 61 oxidized titanium implants, and a provisional fixed bridge was delivered after 1 to 9 days (mean 2.5 d). Nine patients had six implants and one patient had eight implants supporting the bridge. The provisional bridge was replaced with a permanent bridge after 2 to 7 months (mean 4.1 mo) of loading. Resonance frequency analysis (RFA) for implant stability measurements was made at implant placement in eight patients and in conjunction with permanent bridge connection in five patients. The patients were followed up for 1 year with clinical and radiographic examinations.Results:Four implants (6.6%) were lost in one patient after 10 weeks of loading owing to an infection. All other implants were clinically stable with a mean marginal bone loss of 1.3 ± 0.6 mm after 1 year of loading. RFA showed a mean primary stability of 60.1 ± 3.6 ISQ (implant stability quotient), which increased to 62.8 ± 1.6 ISQ after, on average, 4 months.Conclusions:The results from this limited study on 10 cases indicate that early loading protocols can be applied for cross‐arch dental bridges supported by six to eight implants in the maxilla. However, more clinical trials are needed to establish the long‐term predictability of the treatment.
Tissue Reactions to Abutment Shift: An Experimental Study in Dogs
Authors: Abrahamsson Ingemar , Berglundh Tord , Sekino Satoshi , Lindhe Jan 
Published: October 2006

ABSTRACT Background: Standard protocols for the clinical use of dental implants often include the placement of healing abutments prior to standard or custom‐made abutments. The tissue response to a single shift from a healing abutment to a permanent abutment has not been studied. Purpose: The aim of the present experiment was to study tissue reactions that may occur following the removal of a healing abutment and the placement of a permanent abutment. Materials and Methods: In six beagle dogs, all mandibular premolars were extracted. Three months later three fixtures of the Astra Tech Implants Dental System (Astra Tech AB, Mölndal, Sweden) were installed in each edentulous premolar region. An additional 3 months later, the first abutment connection was performed. In two sites on each side of the mandible, healing abutments were placed; in the remaining site, a Uni‐abutment (Astra Tech AB) was used. The two healing abutments were removed 2 weeks later, and one Uni‐abutment and one prepable abutment were placed. A plaque‐control period was initiated, and 6 months later block biopsies were obtained. The biopsies were prepared for histometric and morphometric examination. Radiographs were obtained at fixture placement, 2 weeks after the first abutment connection, and 6 months later. Results: The length of the barrier epithelium, the height of the connective tissue attachment, and the level of the marginal bone did not differ between the three abutment groups. The major part of the radiographic bone loss during the experiment took place prior to or immediately after abutment connection; only small bone level alterations occurred during the subsequent 6‐month period. Conclusions: The shift from a healing abutment to a permanent abutment resulted in the establishment of a transmucosal attachment, the dimension and quality of which did not differ from those of the mucosal barrier formed to a permanent abutment placed during a second‐stage surgery.
Early Functional Loading of Unsplinted Roughened Surface Implants with Mandibular Overdentures 2 Weeks after Surgery
Authors: Payne Alan G.T. , Tawse‐Smith Andrew , Thompson W. Murray , Kumara Rohana 
Published: October 2006

ABSTRACT Background: Before early functional loading of unsplinted implants with mandibular overdentures can become widespread, more clinical studies are needed to investigate the success of the approach. Purpose: To evaluate the success rates of two types of roughened titanium surface implants with early 2‐week functional loading of paired mandibular interforaminal implants with overdentures. Materials and Methods: Random allocation divided 24 strictly selected edentulous participants into two groups, with each group to receive a different implant system (ITI Dental Implant System, Straumann AG, Waldenburg, Switzerland; or Southern Implant System, Southern Implants, Irene, South Africa). Two implants were placed in the anterior mandible of all participants using one‐stage standardized surgical procedures. Previously constructed conventional mandibular dentures (opposing maxillary complete dentures) were temporarily relined and worn by the participants for the first 2 weeks; participants used a soft diet. Two weeks after implant surgery and following some mucosal healing, the mandibular dentures had the tissue conditioner removed and the appropriate matrices included for an unsplinted prosthodontic design. Results: No implant from either group was lost. Resonance frequency analysis (RFA) indicated higher primary stability at surgery for the Southern group than for the ITI group, with a statistically significant difference between the groups throughout the study period. The drop in RF values between surgery and 6 weeks was significant and was greater for the Southern group. RFA also indicated stabilized osseointegration between 6 to 12 and 12 to 52 weeks, with no participant showing any decrease in those values over time. Participants with type 3 bone showed a significant improvement in RF values between 12 and 52 weeks, eventually matching those of participants with type 2 bone. There were no significant differences in marginal bone loss, periimplant parameters, or prosthodontic maintenance between the groups over the study period. Conclusions: Using only strict patient selection criteria, 1‐year follow‐up data indicate that early functional loading of ITI and Southern implants with mandibular two‐implant overdentures is possible as early as 2 weeks after implant surgery.
An Image‐Guided System Based on Custom Templates: Case Reports
Authors: Blanchet Eric , Lucchini Jean‐Pierre , Jenny Rene , Fortin Thomas 
Published: October 2006

ABSTRACTBackground:With the use of computer‐assisted surgery and other modern imaging technologies, the surgeon's procedures have been modified.Purpose:The purpose of these case reports is to show the clinical predictability of dental implant placement using an image‐guided system.Material and Methods:An acrylic template is made on the patient model. After computed tomographic examination, a treatment plan is established with appropriate software. To fabricate the surgical template, it is necessary to use a dedicated drilling machine. The first osteotomy is achieved through the template with a 2 mm twist drill. The template is then removed, and the osteotomy is completed, followed by implant placement with standard clinical procedures.Results:An excellent predictability was observed between the planned implants and those placed in the two maxillary cases presented: a full upper screw‐retained bridge and two single units.Conclusions:This new technology improves the treatment outcome and optimizes the surgical procedure.
Fracture Resistance of Endodontically Treated Teeth Restored with Three Different Prefabricated Esthetic Posts
Authors: MACCARI PAULO C. A. , CONCEIÇÃO EWERTON N. , NUNES MAURO F. 
Published: October 2006

ABSTRACT Purpose: This study was undertaken to evaluate the role of composition of prefabricated esthetic posts in fracture resistance of endodontically treated teeth in vitro. Materials and Methods: Thirty human, single‐rooted teeth (maxillary central incisors and canines) with similar root dimensions, extracted for therapeutic reasons, were used in this study. The crowns were removed below the cementoenamel junction to obtain a standard root length of 17 mm. The roots were endodontically treated following the conventional manual technique and randomly assigned to three groups (n = 10) according to the post used: Aestheti‐Post, Bisco, Schaumberg, Illinois; FibreKor Post, Jeneric/Pentron, Wallingford, Connecticut; and CosmoPost, Ivoclar Vivadent, Schaan, Liechtenstein. The root canals were rendered patent, and the root preparations were standardized through flaring with the manufacturers' drills included in the respective kits. The posts were cemented with an adhesive system and a resin cement (All‐Bond 2 and C & B, Bisco, respectively), according to the manufacturers' directions. Composite resin (Tetric Ceram, Ivoclar Vivadent) crowns were built up using a preformed polyester matrix, and the specimens were mounted in metallic rings with cold‐cure acrylic resin and kept in saline solution at 4°C for 24 hours. Fracture resistance was then determined using an EMIC DL‐2000 universal testing machine. The crosshead speed was 0.5 mm/min with the 45‐degree compressing load at the middle third of the crown. Data were analyzed using one‐way analysis of variance and Tukey'stest (p<.001). Results: Mean fracture resistance was as follows: Aestheti‐Post, 83.5 kgf; FibreKor Post, 85.7 kgf; and CosmoPost, 36.5 kgf. The fracture strength of CosmoPost was significantly lower than that of the other posts. Teeth restored with CosmoPost had post fractures, and in three specimens, those were associated with root fractures. Teeth restored with the other two posts presented fractures on the composite crowns.CLINICAL SIGNIFICANCECompared with ceramic posts, carbon‐fiber and glass‐fiber prefabricated esthetic posts provide endodontically treated teeth higher fracture resistance.
Color Measurements as Quality Criteria for Clinical Shade Matching of Porcelain Crowns
Authors: DANCY WM KEVIN , YAMAN PETER , DENNISON JOSEPH B. , O'BRIEN WILLIAM J. , RAZZOOG MICHAEL E. 
Published: October 2006

ABSTRACTStatement of Problem: The ability of a dentist to select and communicate an acceptable shade match to a dental laboratory may be the most important factor in esthetic restorative dentistry. Purpose: The purpose of this study was to evaluate the use of instrumental color measurement in clinical shade matching of porcelain‐fused‐to‐metal (PFM) and all‐porcelain crowns. The relative effects of clinical and laboratory factors related to shade matching for PFM and all‐porcelain crowns were also evaluated.Materials and Method: Forty patients treatment planned to receive PFM or all‐porcelain crowns made up the study population/The patients were randomly divided into two groups for shade selection: conventional visual assessment and photocolorimetric analysis. At the preparation appointment, a photograph was taken of the target tooth along with four shade guide tabs selected by the two visual observers. The crown was fabricated by either visual selection or by the lowest E* values determined from the photographs and a spectrophotometer. The same dental laboratory fabricated all 40 restorations. At the cementation appointment, clinical criteria were used to evaluate anatomy/contour, surface texture, and the amount of glaze as it relates to color perception before the restoration was cemented.Results: The mean E* between the reference tooth before preparation and the crown before cementation in the visual assessment group was 10.49 (± 14.6), whereas the mean E* in the photocolorimetric group was 8.99 (± 5.7). Analysis of data showed that the observers and the colorimetric technique were perfect (E* = 0) 41% of the time and varied (E* = 0.1 or higher) 59% of the time. Data collected further showed no significant difference or correlation between shade selection methods and the evaluated clinical criteria.Conclusions: These results provide evidence that there is no significant difference in shade selection using the conventional visual assessment by two experienced clinicians or the photocolorimetric technique.CLINICAL SIGNIFICANCEThe use of photocolorimetric analysis in shade selection can serve as a reliable alternative to conventional visual shade selection. This method is useful for clinicians who have difficulty with shade selection.
Shear Bond Strength of Enamel Treated with Seven Carbamide Peroxide Bleaching Agents
Authors: BASTING ROBERTA TARKAN. , RODRIGUES JOSÉ AUGUSTO , SERRA MÔNICA CAMPOS , PIMENTA LUIZ ANDRÉFREIRE 
Published: October 2006

ABSTRACTPurpose::Lower average values of bond strength of adhesive systems to enamel bleached with 10% carbamide peroxide agents have been reported, but the effects of higher concentrations of carbamide peroxide bleaching agents are still unknown. The aim of this in vitro study was to evaluate the shear bond strength of enamel treated with different concentrations of carbamide peroxide to an adhesive system after a postbleaching period of storage in artificial saliva for 15 days.Materials and Methods:Seven carbamide peroxide bleaching agents with concentrations varying from 10 to 22% were analyzed. A placebo agent was used as a control group. The agents were applied on the enamel fragments for 8 h/d for 42 days. During the remaining time, the specimens were stored in artificial saliva. After that time, the fragments were stored individually in artificial saliva for 15 days. An adhesive system was used to bond resin‐based composite cylinders on the enamel surface. Shear bond strength tests were performed and the fractured surfaces of the specimens were visually examined with a stereomicroscope at ×30.Results:The analysis of variance did not show differences in shear bond strength among the treatment agents. The fractures for all treatment agents were predominantly adhesive.Conclusion:After 15 days storage in artificial saliva, different concentrations of carbamide peroxide bleaching agents and a placebo agent had the same enamel shear bond strength values.