bluuebunny/crossref_metadata_2025_split huggingface dataset:
Short‐term clinical results of Nobel Direct implants: a retrospective multicentre analysis
Authors: Sennerby Lars , Rocci Antonio , Becker William , Jonsson Lars , Johansson Lars‐Åke , Albrektsson Tomas 
Published: January 2008

AbstractPurpose: The present retrospective clinical study was undertaken to evaluate the survival rate and marginal bone conditions around Nobel Direct one‐piece implants. The purpose was also to compare the results with when these implants are used for immediate/early loading with implants allowed to heal before loading.Material and methods: Forty‐three consecutive patients previously treated with 117 Nobel Direct implants at four different centres were evaluated. The implants had been used in both jaws for treatment after loss of single and multiple teeth. Immediate/early loading (within 2 weeks) with a provisional crown/bridge was applied to 95 implants, while 22 implants healed unloaded for 6 weeks to 6 months before loading. Calculations of marginal bone loss were performed in radiographs taken at placement and after an average of 10.2 months (range 1–18 months) of loading.Results: Six (5.1%) of the 117 implants were removed during the follow up. All failed implants belonged to the immediate/early loading group giving a failure rate of 6.3% for this group and 0% for two‐stage implants. The failure rate was higher for flapless (7.9%) than for flap surgery (0%). The marginal bone loss was −2.4 mm (SD 1.5) for all implants, while 37.6% showed more than 3 mm of loss during the follow up. Bone loss increased with time of follow up. Implants subjected to immediate/early loading showed more bone loss than two‐stage implants: −2.6 mm (SD 1.5) vs. −1.6 mm (SD 1.1). Moreover, 41.3% of immediately loaded and 22.7% of two‐stage implants presented with more than 3 mm of bone loss.Conclusions: This short‐term retrospective analysis showed a poor clinical outcome of Nobel Direct implants. Extensive marginal bone loss (>3 mm) was found around more than 1/3 of the implants evaluated. Less resorption and no failures were experienced when implants were allowed to heal from 6 weeks to 6 months before occlusal loading. Within the limitations of the present study design, data indicate that immediate loading, the use of this implant for multi‐unit constructions and flapless surgery are risk factors for failure of Nobel Direct implants.
Step‐wise analysis of the dental implant insertion process using the finite element technique
Authors: Van Staden Rudi C. , Guan Hong , Johnson Newell W. , Loo Yew‐Chaye , Meredith Neil 
Published: January 2008

AbstractObjectives: Using the finite element method (FEM), the insertion process of a dental implant into a section of the human mandible is analysed. The ultimate aim of this article is to advance the use of an innovative engineering approach in dental practices, especially in the process of dental implantation.Material and methods: The FEM and analysis techniques are used to replicate and evaluate the stress profile created within the mandible during the implantation process.Results: The von Mises stress profiles in both cancellous and cortical bone are examined during implant insertion. The applied torque and the insertion stage are found to strongly influence the resulting stress profile within the surrounding jawbone.Conclusions: Through the combination of both dental and engineering expertise, a simplified and efficient modelling technique is developed. This improves the understanding of the biomechanical reaction that the jawbone exhibits due to the insertion of implant. The current research is a pilot study using the FEM to model and simulate the dental implantation process. The assumptions made in the modelling and simulation process are: (1) the implantation process is simulated as a step‐wise process instead of a continuous process; (2) the implant is parallel threaded and the implant does not rotate during insertion into the jawbone. Although the modelling and simulation techniques had to be simplified, a significant amount of information is gained that helps lay a good foundation for future research. Recommendations for future studies include the variation of the torque applied during the implantation process and upgrading the software capabilities to simulate the full dynamical process of implantation.
Immediately loaded titanium implant with a tissue‐stabilizing/maintaining design (‘beyond platform switch’) retrieved from man after 4 weeks: a histological and histomorphometrical evaluation. A case report
Authors: Degidi Marco , Iezzi Giovanna , Scarano Antonio , Piattelli Adriano 
Published: January 2008

AbstractBackground: After implant insertion and loading, crestal bone usually undergoes remodeling and resorption. If the horizontal relationship between the outer edge of the implant and a smaller‐diameter component (‘platform switching’) is altered, there seems to be reduced crestal bone loss. Immediate loading allows immediate restoration of esthetics and function, reduces morbidity, and facilitates functional rehabilitation.Materials and methods: Three Morse cone connection implants were inserted in the right posterior mandible in a 29‐year‐old partially edentulous patient. The platform of the implant was inserted 2 mm below the level of the alveolar crest. After a 1‐month loading period, the most distal mandibular implant was retrieved with a trephine bur for psychological reasons.Results: At low‐power magnification, it was possible to see that bone was present 2 mm above the level of the implant shoulder. No resorption of the coronal bone was present. No infrabony pockets were present. At the level of the shoulder of the implant, it was possible to observe the presence of dense connective tissue with only a few scattered inflammatory cells. Newly formed bone was found in direct contact with the implant surface. The bone–implant contact percentage was 65.3±4.8%.Conclusions: Abutments smaller than the diameter of the implant body (platform switching) in combination with an absence of micromovement and microgap may protect the peri‐implant soft and mineralized tissues, explaining the observed absence of bone resorption. Immediate loading did not interfere with bone formation and did not have adverse effects on osseointegration.
Osteoprotegerin levels in peri‐implant crevicular fluid
Authors: Arıkan Fatih , Buduneli Nurcan , Kütükçüler Necil 
Published: January 2008

AbstractAims: To evaluate the levels of soluble receptor activator of nuclear factor‐κB ligand (sRANKL) and osteoprotegerin (OPG) in crevicular fluid of endosseous dental implants.Methods: Eighty‐six implants in 39 patients were evaluated. All patients were treated with root‐type implants placed at least 16 months and loaded at least 12 months before the examination. Peri‐implant crevicular fluid (PICF) samples were obtained from buccal and lingual aspects of implants. Modified plaque index, probing depth, gingival index, and bleeding on probing (BOP) were recorded at four sites per implant. PICF levels of sRANKL and OPG were analysed by ELISA. Spearman's correlations were utilised to relate biochemical data and clinical parameters.Results: The PICF level of sRANKL did not show significant correlation with the clinical parameters or the OPG level. The total amount of OPG was positively correlated with PICF volume, gingival index, and BOP (P<0.05) and negatively correlated with pack years (P<0.05).Conclusion: The findings of this preliminary study suggest that the crevicular fluid level of OPG deserves further investigation as a possible marker to evaluate the health status of surrounding tissues of dental implants, as this was not the case for the sRANKL level. Larger scale studies, particularly in peri‐implantitis cases, may shed more light on this subject.
Surgical factors influencing mesiodistal implant angulation
Authors: Payer Michael , Kirmeier Robert , Jakse Norbert , Pertl Christof , Wegscheider Walther , Lorenzoni Martin 
Published: January 2008

AbstractObjectives: The aim of this experimental study was to identify relevant surgical parameters influencing the mesiodistal angular deviation of dental implants.Material and methods: Pilot drillings of 2 mm diameter were performed in bovine ribs with a parallelometer. The subsequent preparation of the implant socket was performed freehand. Utilizing six different implant systems, at least 80 drillings per system of different diameters were performed. The pilot drillings were marked with 2 mm steel pins and cephalometric radiographs were taken. The mesiodistal angle between the longitudinal implant axis and the marked pilot drillings was measured and evaluated by a blinded investigator. To evaluate the influence of the surgeons' experience, their drillings were compared with those of a group of unexperienced surgeons. Additionally, the influence of drilling speed and size of bur steps on drilling accuracy were evaluated.Results: The difference between the lowest value of 0.91° of mesiodistal angular deviation found for 3i® implants and the highest of 1.36° for Ankylos® implants was of low statistical significance (P=0.065). Drillings of experienced surgeons showed less deviation compared with those of a beginners group (P<0.0001). Higher deviations were measured when a bur size was skipped. Drillings performed at high speed showed significantly higher deviations than those with fewer rewinds per minute.Conclusion: In order to achieve precise implant angulation, all bur diameters available should be used. Utilizing low drilling speeds results in less mesiodistal deviation. The surgeon's experience seems to be the most relevant factor in precise implant placement.
Dental implants placed in previously failed sites: survival rate and factors affecting the outcome
Authors: Machtei Eli E. , Mahler Dan , Oettinger‐Barak Orit , Zuabi Otman , Horwitz Jacob 
Published: January 2008

AbstractObjectives: The purpose of the present study was to evaluate the survival rate of dental implants in previously failed implant sites. In addition, factors that might affect the outcome of these redo procedures were also explored.Material and methods: Patients that had failed dental implants, which were replaced with the same implant type at the same site, were included. Data on the failed implants were collected. The same parameters, along with the interval between retrieval and re‐implantation, were collected for the second set of implants. Descriptive statistics were used to describe the patients and implants. Life table analysis of these implants was tabulated for both implant sets. The effect of systemic, environmental and local factors on the survival of the redo dental implants was evaluated.Results: Fifty‐six patients with a total of 79 redo implants were included in this study. Implants were followed for 7–78 months (mean 29.9±2). Thirteen implants failed that resulted in an overall survival rate of 83.5%. Successful implants had greater diameter (4.05±0.52 mm) than failed implants (3.72±0.56 mm); however, these differences were only marginal (P=0.06). Conversely, smoking habits, implants length and location, mode of placement and spontaneous exposure did not have a significant effect on the outcome of this procedure.Conclusion: Redo of dental implants has a lesser survival rate compared with previous reports for implants in pristine sites. These results were not associated with most implant‐ and/or patient‐related factors. Thus, a possible negative effect that is associated with the specific implant's site might account for this phenomenon.
Effect of polyphosphoric acid pre‐treatment of titanium on attachment, proliferation, and differentiation of osteoblast‐like cells (MC3T3‐E1)
Authors: Maekawa Kenji , Yoshida Yasuhiro , Mine Atsushi , Van Meerbeek Bart , Suzuki Kazuomi , Kuboki Takuo 
Published: January 2008

AbstractPurpose: To evaluate the effect of polyphosphoric acid (PPA) pre‐treatment of titanium (Ti) on the initial attachment, proliferation, and differentiation of mouse osteoblast‐like cells (MC3T3‐E1).Materials and methods: Adsorption of PPA to Ti was achieved by immersing Ti disks (15 mm in diameter) into 0, 1, and 10 wt% PPA and 10 wt% orthophosphoric acid (OPA) for 24 h. On each pre‐treated Ti disk, 5.0 × 104 MC3T3‐E1 cells were seeded, and 1, 3, and 5 h later cell attachment was evaluated. Cell proliferation was also determined 1, 3, and 5 days after cell seed. Cell differentiation was evaluated 5, 10, and 15 days after cell seed using osteoblast marker gene expression. Total RNA was purified from each culture and Type‐I collagen, alkaline phosphatase, and osteocalcin mRNA expression levels were measured by real‐time reverse transcription polymerase chain reaction.Results: Adsorption of PPA or OPA to Ti significantly accelerated initial cell attachment at every time point (P<0.0001). As with cell attachment, cell proliferation was also accelerated on the PPA‐treated Ti disks in a dose‐dependent manner at every time point (P<0.0001). However, OPA‐treated Ti disks did not enhance the cell proliferation. Regarding osteoblastic differentiation, PPA‐treated Ti significantly accelerated the Type‐I collagen gene expression at 5 and 10 days after cell seed. Regarding alkaline phosphatase and osteocalcin gene expression, no significant difference was found among the different Ti surface conditions.Conclusion: The accelerated cell behavior following Ti pre‐treatment with PPA is a promising new strategy to fabricate bioactive Ti implants.
Association of vitamin D receptor gene polymorphisms in Chinese patients with generalized aggressive periodontitis
Authors: Li S. , Yang M. H. , Zeng C. A. , Wu W. L. , Huang X. F. , Ji Y. , Zeng J. Q. 
Published: January 2008

Background and Objective:  The clinical features suggest that genetic factors may have a strong influence on susceptibility to aggressive periodontitis. The aim of this study was to investigate the association of vitamin D receptor gene polymorphisms with generalized aggressive periodontitis in Chinese patients.Material and Methods:  A restriction fragment length polymorphism (RFLP) for 10,438,141 C to T (rs1544410, BsmI), 10,382,063 A to G (rs731236, TaqI), 10,382,143 C to A (rs7975232, ApaI) and 10,416,201 A to G (rs2228570, FokI) of vitamin D receptor gene was analysed by polymerase chain reaction, followed by digestion with restriction enzymes and gel electrophoresis. The genotypes of 51 generalized aggressive periodontitis patients and 53 periodontally healthy control subjects were analysed. The genotypic and allelic frequencies of each polymorphism site for the patients and control subjects were compared.Results:  The distribution of vitamin D receptor FokI genotypes and alleles between the two groups was significantly different (p = 0.043 and p = 0.012, respectively). The F allele seemed to increase the susceptibility of aggressive periodontitis (odds ratio = 2.02, 95% confidence interval = 1.16–3.50) in Chinese patients. There was no significant difference in the genotype distribution or the allele frequencies of vitamin D receptor BsmI, ApaI and TaqI between two groups.Conclusion:  The study indicates that FokI polymorphism of vitamin D receptor gene might be associated with generalized aggressive periodontitis in Chinese patients. In addition, the carriage of F allele increases the risk of developing generalized aggressive periodontitis.
Reattachment of Anterior Teeth Fragments: A Conservative Approach
Authors: MACEDO GEORGIA V. , DIAZ PATRICIA I. , DE O. FERNANDES CARLOS AUGUSTO , RITTER ANDRÉ V. 
Published: January 2008

ABSTRACTCoronal fractures of the anterior teeth are a common form of dental trauma that mainly affects children and adolescents. One of the options for managing coronal tooth fractures when the tooth fragment is available and there is no or minimal violation of the biological width is the reattachment of the dental fragment. Reattachment of fractured tooth fragments can provide good and long‐lasting esthetics (because the tooth’s original anatomic form, color, and surface texture are maintained). It also restores function, provides a positive psychological response, and is a relatively simple procedure. Patient cooperation and understanding of the limitations of the treatment is of utmost importance for good prognosis. This article reports on two coronal tooth fracture cases that were successfully treated using tooth fragment reattachment.CLINICAL SIGNIFICANCEReattachment of fractured tooth fragments offers a viable restorative option for the clinician because it restores tooth function and esthetics with the use of a very conservative and cost‐effective approach.(J Esthet Restor Dent 20:5–20, 2008)
Implant Replacement of the Maxillary Central Incisor Utilizing a Modified Ceramic Abutment (Thommen SPI ART) and Ceramic Restoration
Authors: SCHNEIDER ROBERT 
Published: January 2008

ABSTRACTThe prosthetic restoration of a missing anterior tooth with a dental implant is a challenge. Treatment coordination with a multidisciplinary team is critical in the successful outcome of this type of patient treatment. Newer surgical treatment modalities in the management of hard and soft tissues are becoming common, with very good predictability and long‐term stability. Additionally, the use of advanced dental technology and materials such as sintered zirconium allows the restorative practitioner the opportunity to fabricate an esthetic, precise‐fitting, biocompatible, and strong definitive prosthesis for the patient, with good longevity.CLINICAL SIGNIFICANCEThe use of an all‐ceramic abutment and restoration is described, along with the “soft tissue sculpting” procedure through the use of a custom provisional restoration. The relative ease and convenience of the procedure is also illustrated.(J Esthet Restor Dent 20:21–28, 2008)
Long‐Term Antibacterial Effects and Physical Properties of a Chlorhexidine‐Containing Glass Ionomer Cement
Authors: TÜRKÜN L. S¸EBNEM , TÜRKÜN MURAT , ERTUG˘RUL FAHINUR , ATES¸ MUSTAFA , BRUGGER STEFAN 
Published: January 2008

ABSTRACTStatement of the Problem:  Many regions in the world do not have electricity, water, or access to dental facilities that allows the treatment of caries with dental handpieces and rotary burs. For restorative techniques used in these regions, an antibacterial self‐adherent glass ionomer material would contribute considerably.Purpose:  This study aimed to test if chlorhexidine diacetate (Fluka BioChemika, Buchs, Switzerland)‐ or chlorhexidine digluconate (Sigma‐Aldrich, Steinheim, Germany)‐added ChemFil Superior glass ionomer cement (Dentsply DeTrey, Konstanz, Germany) had any long‐term antibacterial effect against certain oral bacteria and to test the new formulation’s physical properties.Materials and Methods:  ChemFil Superior was used as a control. Chlorhexidine diacetate (powder) was added to the powder and chlorhexidine digluconate (liquid) was mixed with the powder in order to obtain 0.5, 1.25, and 2.5% concentrations of the respective groups. Setting time, compressive strength, and acid erosion were tested according to ISO 9917‐1. Working time, hardness, diametral tensile strength, and biaxial flexural strength were also determined. Long‐term antimicrobial activity against S. mutans, L. acidophilus, and C. albicans were tested with the agar diffusion method. Analysis of variance (ANOVA) was used for comparison (p < 0.05).Results:  Regarding the immediate antibacterial effect for S. mutans, all the tested groups showed inhibitions of the strain compared with the control group (p < 0.05), with larger zones for the higher concentration groups and all the diacetates. For L. acidophilus, all the groups were effective compared with the control, but the greatest antibacterial effect was observed with the 2.5% diacetate group. The 2.5% group of chlorhexidine diacetate showed antibacterial activity up to 90 days against S. mutans and up to 60 days against L. acidophilus. The working and setting time, acid erosion test, diametral tensile strength, and biaxial flexural strength of the tested groups were not different from the control ChemFil group. However, the 1.25 and 2.5% groups of chlorhexidine diacetate had significantly lower compressive strengths than the control group. Lower hardness values were obtained with the 0.5 and 2.5% chlorhexidine digluconate groups in comparison with the control group.CLINICAL SIGNIFICANCEThe results of this in vitro investigation demonstrated that chlorhexidine diacetate or digluconate added to the ChemFil Superior glass ionomer material can exhibit long‐term antibacterial effects against S. mutans and L. acidophilus without compromising the physical properties of the material.(J Esthet Restor Dent 20:29–45, 2008)
Polymorphism of the interleukin‐10 gene in polycystic ovary syndrome
Authors: Karadeniz M. , Erdogan M. , Zengi A. , Tamsel S. , Berdeli A. , Saygili F. , Yilmaz C. 
Published: January 2008

SummaryInterleukin (IL)‐10 is a major anti‐inflammatory cytokine that has been associated with obesity and type 2 diabetes. We aimed to evaluate the IL‐10 gene polymorphisms in polycystic ovary syndrome (PCOS) and control subjects. Ninety‐one young women with PCOS and 74 healthy control women were included in our study. All subjects underwent venous blood drawing for complete hormonal assays, lipid profile, glucose, insulin and IL‐10 gene polymorphism genetic analysis and carotid intimae media thickness (CIMT) were measured. The genotype and allele frequencies showed similar ratios between both the control and the patient group. The AA and AG genotypes in IL‐10 polymorphism seemed to be relatively high, but statistically no significant difference has been detected in GG genotype. Our results show that IL‐10 gene polymorphism of PCOS patients has no effect on inflammatory markers, metabolic parameters (fasting insulin, fasting glucose, HOMA‐IR), carotid intimae media thickness and Ferriman‐ Gallwey scoring. These data will be different in PCOS patients with different ethnical origin.
Aspherical supernova explosions and formation of compact black hole low-mass X-ray binaries
Authors: Li Xiang-Dong 
Published: January 2008

Abstract
It has been suggested that black hole low-mass X-ray binaries (BHLMXBs) with short orbital periods may have evolved from BH binaries with an intermediate-mass secondary, but the donor star seems to always have higher effective temperatures than measured in BHLMXBs. Here we suggest that the secondary star is originally an intermediate-mass (∼2–5 M⊙) star, which loses a large fraction of its mass due to the ejecta impact during the aspherical suparnova explosion that produced the BH. The resulted secondary star could be of low mass (≲1 M⊙). Magnetic braking would shrink the binary orbit and drive mass transfer between the donor and the BH, producing a compact BHLMXB.