bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digitally Planned, Immediately Loaded Dental Implants with Prefabricated Prostheses in the Reconstruction of Edentulous Maxillae: A 1‐Year Prospective, Multicenter Study
Authors: Johansson Björn , Friberg Bertil , Nilson Hans 
Published: September 2008

ABSTRACTBackground: The introduction of digital planning programs has made it possible to place dental implants in preplanned positions and being immediately functionally loaded by using prefabricated prostheses.Purpose: The aim of this multicenter study was to describe the 1‐year results of digitally planned, immediately loaded edentulous maxillae.Materials and Methods: A total of 312 implants (Brånemark System®, TiUnite RP, Nobel Biocare, Göteborg, Sweden) in 52 patients from eight Scandinavian clinics were digitally planned, surgically as well as prosthetically, by using the NobelGuide® (Nobel Biocare AB, Göteborg, Sweden) and received prefabricated, immediately loaded fixed prosthetic constructions in the maxillae. Individual implant stability was manually tested at 1‐year follow‐up.Results: All patients received a Procera Implant Bridge® (Nobel Biocare AB); however, in two cases, the bridges were reconstructed due to misfit. In five patients, difficulties in getting the surgical guide completely in position, and in five patients, getting the prostheses completely seated, were noted.All but four patients fulfilled the 1‐year follow‐up. Two implants were lost during the study period, resulting in a cumulative survival rate of 99.4%. The mean marginal bone resorption from implant placement to the 1‐year follow‐up was 1.3 mm (SD 1.28). More than 2 mm of marginal resorption was noted in 19% of the implants at this instant. The most frequently reported complications during the first year were gingival hyperplasia and prosthesis‐related problems (prosthesis screw loosening, occlusal fractures, and occlusal adjustments).Conclusion: The 1‐year results in this multicenter are promising regarding implant and bridge stability; however, the study is planned to be running for at least 3 years.
RFA Values of Implants Placed in Sinus Grafted and Nongrafted Sites after 6 and 12 Months
Authors: Degidi Marco , Daprile Giuseppe , Piattelli Adriano 
Published: September 2008

ABSTRACTBackground: Maxillary sinus floor elevation surgery is widely used as a preimplantology method to permit implant insertion. Nevertheless, very few data are available about long‐term stability of dental implants inserted in grafted sites.Purpose: The aims of the present study were to evaluate the evolution of resonance frequency analysis (RFA) values at 6 and 12 months from the implant insertion in sinus grafted sites and nongrafted sites.Materials and Methods: In 14 patients, 80 Xive implants (Dentsply Friadent GmbH, Mannheim, Germany) were inserted. Sixty‐three implants were inserted in a site previously treated with a sinus lift; 17 implants were inserted in healed or postextraction sites. For each implant diameter, length, bone density, insertion torque, and percentage of implant fixed to a nongrafted bone were recorded. RFA values at implant insertion after 6 and 12 months were recorded.Results: After 6 and 12 months, grafted sites showed higher RFA values than the control sites; after 12 months, the difference was statistically significant (.007). A statistically significant positive correlation was found between resonance frequency values and bone quality after 12 months (.05). No statistically significant correlation between RFA values and all the other variables considered was found.Conclusions: Sites treated with sinus lift can offer good long‐term stability. After 6 and 12 months, the geometric characteristics of the implant are no longer important to obtain high RFA values, and the bone–implant interface seems to be determinant.
Stability of Prototype Two‐Piece Zirconia and Titanium Implants after Artificial Aging: An In Vitro Pilot Study
Authors: Kohal Ralf‐Joachim , Finke Hans Christian , Klaus Gerold 
Published: September 2008

ABSTRACTBackground: Zirconia oral implants are a new topic in implant dentistry. So far, no data are available on the biomechanical behavior of two‐piece zirconia implants. Therefore, the purpose of this pilot investigation was to test in vitro the fracture strength of two‐piece cylindrical zirconia implants after aging in a chewing simulator.Materials and Methods: This laboratory in vitro investigation comprised three different treatment groups. Each group consisted of 16 specimens. In group 1, two‐piece zirconia implants were restored with zirconia crowns (zirconia copings veneered with Triceram®; Esprident, Ispringen, Germany), and in group 2 zirconia implants received Empress® 2 single crowns (Ivoclar Vivadent AG, Schaan, Liechtenstein). The implants, including the abutments, in the two zirconia groups were identical. In group 3, similar titanium implants were reconstructed with porcelain‐fused‐to‐metal crowns. Eight samples of each group were submitted to artificial aging with a long‐term load test in the artificial mouth (chewing simulator). Subsequently, all not artificially aged samples and all artificially aged samples that survived the long‐term loading of each group were submitted to a fracture strength test in a universal testing machine.For the pairwise comparisons in the different test groups with or without artificial loading and between the different groups at a given artificial loading condition, the Wilcoxon rank‐sum test for independent samples was used. The significance level was set at 5%.Results: One sample of group 1 (veneer fracture), none of group 2, and six samples of group 3 (implant abutment screw fractures) failed while exposed to the artificial mouth. The values for the fracture strength after artificial loading with 1.2 million cycles for group 1 were between 45 and 377 N (mean: 275.7 N), in group 2 between 240 and 314 N (mean: 280.7 N), and in the titanium group between 45 and 582 N (mean: 165.7 N). The fracture strength results without artificial load for group 1 amounted to between 270 and 393 N (mean: 325.1 N), for group 2 between 235 and 321 N (mean: 281.8 N), and between 474 and 765 N (mean: 595.2 N) for the titanium group. The failure mode during the fracture testing in the zirconia implant groups was a fracture of the implant head and a bending/fracture of the abutment screw in the titanium group.Conclusions: Within the limits of this pilot investigation, the biomechanical stability of all tested prototype implant groups seems to be – compared with the possibly exerted occlusal forces – borderline for clinical use. A high number of failures occurred already during the artificial loading in the titanium group at the abutment screw level. The zirconia implant groups showed irreparable implant head fractures at relatively low fracture loads. Therefore, the clinical use of the presented prototype implants has to be questioned.
Comparative Analysis of Immediate Functional Loading and Immediate Nonfunctional Loading to Traditional Healing Periods: A 5‐Year Follow‐Up of 550 Dental Implants
Authors: Degidi Marco , Iezzi Giovanna , Perrotti Vittoria , Piattelli Adriano 
Published: September 2008

ABSTRACTBackground: Clinical, radiographical, and histological findings have shown that immediately loaded implants show the presence of mineralized tissues at the interface.Purpose: The aim of this study was to compare an immediate loading protocol with a two‐staged one using an implant with a square thread design.Materials and Methods: One hundred fifty‐five consecutive patients (71 men, 84 women), aged between 18 and 78 years (mean: 54 years) participated in this study. A total of 550 implants (Maestro; BioHorizons, Birmingham, AL, USA) were inserted. In group A, 264 implants were inserted in 82 patients with immediate functional loading with occlusal contact if the patients were completely edentulous, or with immediate nonfunctional loading without occlusal contact if the patients were partially edentulous. In group B, 286 implants were inserted in 73 patients with a one‐stage or two‐stage surgical procedure. All patients were followed for at least 5 years.Results: In the immediately loaded implants group, three implants failed, all in posterior mandibular sites, with an overall 98.8% 5‐year survival rate. In the control group, no implant failed, with a 100% 5‐year survival rate. No statistically significant differences were found in the survival rates of the implants in the two groups.Discussion: A very high implant survival rate was also present in our series for the immediately loaded implants. All the three failed implants were retrieved from the same patient, who had poor oral hygiene, after a loading period of 5 years. These data can suggest that, from a clinical point of view, an abbreviated healing period is compatible with the development and maintenance over a longer time period (5 years) of mineralized tissues at the interface with dental implants.Conclusion: We can then conclude that shorter healing periods can be highly satisfactory from a clinical point of view.
Outcome of Brånemark Novum® Implant Treatment in Edentulous Mandibles: A Retrospective 5‐Year Follow‐Up Study
Authors: Gualini Federico , Gualini GianLuigi , Cominelli Roberto , Lekholm Ulf 
Published: September 2008

ABSTRACTBackground: A gradual progression from a two‐stage surgical technique to a one‐stage and even immediate surgical protocol has occurred during the last decade with most oral implant systems. However, every new approach must obviously be reported individually, with long‐term results, in order to assess whether the changes have any real patient value.Purpose: The aim of the present report was to retrospectively review the 5‐year outcome of patients treated with the Brånemark Novum® (Nobel Biocare AB, Göteborg, Sweden) protocol.Methods: The first 15 patients treated according to the Novum procedure in a private specialist clinic in Lovere, Italy, were followed‐up with clinical, radiographic, and resonance frequency analyses. All the patients’ fixed constructions had been in function for an average of 5 years. Parameters recorded were implant survival, prosthesis success, oral hygiene and mucosal health, marginal bone remodeling, type and frequency of complications, and patient's opinion of the treatment outcome.Results: After 5 years, the cumulative survival rate for implants was 91%, and for inserted bridge constructions it was 87%. Very small changes in implant stability occurred during implant loading from 1 to 5 years. Oral health conditions were good; 87% of mucosal quadrants around the implants were free from signs of inflammation. Very small marginal bone height changes were observed at the implants during the examination period, and except for four implant losses reported, severe complications were few. All patients were satisfied with the functional outcome of their constructions, but two patients were not completely happy with the aesthetics of their bridgework as supplied.Conclusion: This report shows 5‐year evidence of acceptably good results with the Brånemark Novum implant technique in edentulous mandibles, when using only three implants to support the fixed bridge construction, and as long as inserted implants become and remain osseointegrated.
Early Laser‐Welded Titanium Frameworks Supported by Implants in the Edentulous Mandible: A 15‐Year Comparative Follow‐Up Study
Authors: Örtorp Anders , Jemt Torsten 
Published: September 2008

ABSTRACTBackground: Comparative long‐term knowledge of different framework materials in the edentulous implant patient is not available for 15 years of follow‐up.Purpose: To report and compare a 15‐year retrospective data on implant‐supported prostheses in the edentulous mandible provided with laser‐welded titanium frameworks (test) and gold alloy frameworks (control).Materials and Methods: Altogether, 155 patients were consecutively treated with abutment‐level prostheses with two early generations of fixed laser‐welded titanium frameworks (titanium group). Fifty‐three selected patients with gold alloy castings formed the control group. Clinical and radiographic 15‐year data were collected and compared for the groups.Results: All patients who were followed up for 15 years (n = 72) still had a fixed prosthesis in the mandible at the termination of the study. The 15‐year original prosthesis cumulative survival rate (CSR) was 89.2 and 100% for titanium and control frameworks (p = .057), respectively (overall CSR 91.7%). The overall 15‐year implant CSR was 98.7%. The average 15‐year bone loss was 0.59 mm (SD 0.56) and 0.98 mm (SD 0.64) for the test and control groups (p = .027), respectively. Few (1.3%) implants had >3.1‐mm accumulated bone loss after 15 years. The most common complications for titanium frameworks were resin or veneer fractures and soft tissue inflammation. Fractures of the titanium metal frame were observed in 15.5% of the patients. More patients had framework fractures in the earliest titanium group (Ti‐1 group) compared to the gold alloy group (p = .034). Loose and fractured implant screw components were few (2.4%).Conclusion: Predictable overall long‐term results could be maintained with the present treatment modality. Fractures of the metal frames and remade prostheses were more common in the test group, and the gold alloy frameworks had a tendency to work better when compared with welded titanium frameworks during 15 years. However, on the average, more bone loss was observed for implants supporting gold alloy frameworks.
Micromotion and Stress Distribution of Immediate Loaded Implants: A Finite Element Analysis
Authors: Fazel A. , Aalai S. , Rismanchian M. , Sadr‐Eshkevari P. 
Published: September 2008

ABSTRACTBackground: Primary stability and micromotion of the implant fixture is mostly influenced by its macrodesign.Purpose: To assess and compare the peri‐implant stress distribution and micromotion of two types of immediate loading implants, immediate loaded screw (ILS) Nisastan and Xive (DENTSPLY/Friadent, Monnheim, Germany), and to determine the best macrodesign of these two implants by finite element analysis.Methods: In this experimental study, the accurate pictures of two fixtures (ILS: height = 13, diameter = 4 mm and Xive: height = 13, diameter = 3.8 mm) were taken by a new digital camera (Nikon Coolpix 5700 [Nikon, Japan], resolution = 5.24 megapixel, lens = 8× optical, 4× digital zoom). Following accurate measurements, the three‐dimensional finite element computer model was simulated and inserted in simulated mandibular bone (D2) in SolidWorks 2003 (SolidWork Corp., MA, USA) and Ansys 7.1 (Ansys, Inc., Canonsburg, PA, USA). After loading (500 N, 75° above horizon), the displacement was displayed and von Mises stress was recorded.Results: It was found that the primary stability of ILS was greater (152 µm) than Xive (284 µm). ILS exhibited more favorable stress distribution. Maximum stress concentration found in periapical bone around Xive (≈30 MPa) was lesser than Nisastan (≈37 MPa).Conclusions: Macrodesign of ILS leads to better primary stability and stress distribution. Maximum stress around Xive was less.
Histomorphometric Evaluation of a Nanothickness Bioceramic Deposition on Endosseous Implants: A Study in Dogs
Authors: Coelho Paulo G. , Cardaropoli Giuseppe , Suzuki Marcelo , Lemons Jack E. 
Published: September 2008

ABSTRACTPurpose: The objective of this study was to evaluate the bone response to a nanothickness bioceramic ion beam‐assisted deposition (IBAD) on endosteal implants in a canine model.Materials and Methods: Alumina‐blasted/acid‐etched (control) and IBAD‐modified (test) implants were characterized by scanning electron microscopy, X‐ray photoelectron spectroscopy + ion beam milling, thin‐film mode X‐ray diffraction, and atomic force microscope. The implants were surgically placed in four dogs' proximal tibiae and remained for 2 and 4 weeks in vivo. Oxytetracycline (10 mg/kg) was administered for bone labeling 48 hours prior to euthanization. Following euthanization, nondecalcified thin sections were prepared for UV and transmitted light microscopy. The amount of bone labeling was evaluated along the length and away from the implant surface by means of a computer software. The % bone‐to‐implant contact (BIC) was determined for each specimen. One‐way analysis of variance at 95% level of significance along with Tukey's post hoc multiple comparisons were utilized for statistical evaluation. The characterization showed Ca‐ and P‐based amorphous coatings with a 20‐ to 50‐nm thickness.Results: In vivo results showed a significant increase in general and site‐specific (to 0.5 mm from the implant surface) bone activity for the 4‐week test implants compared with the control implants. Bone activity levels decreased as a function of distance from the implant surface for all groups. No significant differences in BIC were observed between groups.Conclusions: This study showed that both surfaces were biocompatible and osteoconductive and that a time‐dependent increase in osteoactivity occurred around the test implants.
A Restoratively Driven Ridge Categorization, as Determined by Incorporating Ideal Restorative Positions on Radiographic Templates Utilizing Computed Tomography Scan Analysis
Authors: Elian Nicolas , Ehrlich Brian , Jalbout Ziad , Cho Sang‐Choon , Froum Stuart , Tarnow Dennis 
Published: September 2008

ABSTRACTBackground: The introduction of implants into the field of dentistry has revolutionized the way we evaluate edentulous ridges. In an attempt to evaluate the deficient edentulous ridge, numerous classification systems have been proposed. Each of these classification systems implements a different approach for evaluating and planning treatment for the ridge deficiency.Purpose: The purpose of the present investigation was to propose a restoratively driven ridge categorization (RDRC) for horizontal ridge deformities based on an ideal implant position as determined through implant simulation, utilizing computed tomography (CT) scan images.Materials and Methods: Radiographic templates were developed to capture the ideal restorative tooth position. Measurements were performed using CT scan software in a cross‐sectional view and by virtual placement of a parallel‐sided implant with a 3.25‐mm diameter.Results: Edentulous ridges were divided into five groupings: Group I, simulated implants with at least 2 mm of facial bone, accounted for 19.4% of ridges; Group II, simulated implant completely surrounded by bone, with less than 2 mm of facial plate thickness, accounted for 10.4% of ridges; Group III, wherein dehiscences are detected but no fenestrations are present, accounted for 33.3% of ridges; Group IV, wherein fenestrations are detected but no dehiscence is present, accounted for 6.3% of ridges; and Group V, wherein both dehiscences and fenestrations are present, accounted for 30.6% of ridges.Conclusion: The use of RDRC indicates that a high number of cases in the maxillary anterior area would require augmentation procedures in order to achieve ideal implant placement and restoration.
Comparison of Biomaterial Implants in the Dental Socket: Histological Analysis in Dogs
Authors: Santos Fábio André , Pochapski Márcia Thaís , Martins Marilia Campagnoni , Zenóbio Elton Gonçalves , Spolidoro Luís Carlos , Marcantonio Jr Elcio 
Published: September 2008

ABSTRACTBackground: Bone graft procedures have been used commonly in buco‐maxillo‐facial surgery. For this reason, many researchers have evaluated the bone substitutes.Purpose: The present study evaluated soft and hard tissue reactions to two different hydroxyapatites HAs (synthetic HA and natural HA) and bioactive glass implanted into the sockets immediately after extraction.Materials and Methods: First and third upper and lower premolars, on both sides, were extracted from six female dogs. The alveolar sockets were randomly assigned to four groups: Group 1 – control (unfilled), Group 2 – filled with synthetic hydroxyapatite, Group 3 – filled with bovine bone mineral (natural HA), and Group 4 – filled with bioactive glass. The animals were euthanized at 4 weeks (n = 2), 8 weeks (n = 2), and 28 weeks (n = 2) after extraction. The mandible and maxilla of each animal were removed for histological analysis to determine soft tissue reactions, newly formed bone, bone characteristics, and presence or absence of implanted materials.Results: Most particles of synthetic hydroxyapatite had bone formation on their surface, although some particles showed a layer of fibrous connective tissue. The bovine bone mineral group exhibited particles partially replaced with bone formation. The bioactive glass group showed particles with a thin layer of calcified tissue, but was absent in some specimens, suggesting complete resorption.Conclusion: All biomaterials had similar behavior. Bovine bone mineral, compared to synthetic hydroxyapatite and bioactive glass, showed a larger number of particles covered with osseous tissue. All biomaterials interfered with the socket repair process.
Biogeography and Divergence in Guaiacum sanctum (Zygophyllaceae) Revealed in Chloroplast DNA: Implications for Conservation in the Florida Keys
Authors: Dertien Joseph R. , Duvall Melvin R. 
Published: September 2008

ABSTRACT Guaiacum sanctum (lignumvitae, guayacán) comprises economically important and globally endangered trees endemic to the dry neotropics. These trees were historically over‐harvested and now G. sanctum is among the species listed by IUCN and CITES. Guaiacum sanctum was once found throughout the Florida Keys, but anthropogenic habitat fragmentation and exploitation have left only one significant population, on Lignumvitae Key. The ecology of this population is additionally subject to hurricane‐mediated effects and an endemic parasite. Genetic profiles were determined for the Lignumvitae and putative source populations of G. sanctum to assess variability and to test biogeographic hypotheses. These data were analyzed by phylogenetic and statistical parsimony analyses. The results were most readily interpreted as indicating historical fragmentation followed by long‐term isolation. However, recent dispersal or gene flow could not be entirely excluded. Both types of analyses strongly support a significant genetic divergence between Caribbean and Mexican populations of G. sanctum and also suggest bidirectional dispersal of G. sanctum into Lignumvitae Key from both the Caribbean and Mexico. These results inform the process of restoring G. sanctum in the Keys.
Puzzling X-rays from the new colliding wind binary Wolf–Rayet 65 (WC9d)
Authors: Oskinova L. M. , Hamann W.-R. 
Published: September 2008

Abstract
We report the discovery of variability in the X-ray emission from the Wolf–Rayet type star WR 65. Using archival Chandra data spanning over 5 yr, we detect changes of the X-ray flux by a factor of 3 accompanied by changes in the X-ray spectra. We believe that this X-ray emission originates from wind–wind collision in a massive binary system. The observed changes can be explained by the variations in the emission measure of the hot plasma, and in the different absorption column along the binary orbit. The X-ray spectra of WR 65 display prominent emission features at wavelengths corresponding to the lines of strongly ionized Fe, Ca, Ar, S, Si and Mg. WR 65 is a carbon-rich WC9d star that is a persistent dust maker. This is the first investigation of any X-ray spectrum for a star of this spectral type. There are indications that the dust and the complex geometry of the colliding wind region are pivotal in explaining the X-ray properties of WR 65.