bluuebunny/crossref_metadata_2025_split huggingface dataset:
Astra Tech and Brånemark System Implants: A Prospective 5‐Year Comparative Study. Results after One Year
Authors: Astrand Per , Engquist Bo , Dahlgren Simon , Engquist Eva , Feldmann Hartmut , Gröndahl Kerstin 
Published: April 2007

ABSTRACT Background: Endosseous dental implants are used frequently, and many implant systems are available. The scientific documentation of the implant system presents a great variation, and it is often difficult to compare studies of different systems. Purpose: The aim of this study was to compare two Swedish implant systems (Astra Tech and Brånemark System± implants), in a prospective randomized study. Materials and Methods: Sixty‐six patients were equally distributed between the two implant systems; 184 Astra Tech and 187 Brånemark System implants were used. The patients have been followed annually with clinical and radiographic examinations. The results after 1 year are reported. Results: The abutment procedure was found to be easier and less time‐consuming with Astra Tech than with Brånemark implants. The operation times in minutes (mean ± SEM) were for the respective implant 35 ± 4.0 and 51 ± 4.8 in the maxilla and 32 ± 3.8 and 43 ± 2.4 in the mandible. The differences in both cases were significant: p <.02 and p <.05, respectively. The failure rate for Astra Tech implants was 0.5% and for Brånemark implants 4.3%. The difference was significant (p <.05); however, taking into account that five of the eight implant losses in the Brånemark implant group occurred in one patient, an intraindividual correlation cannot be excluded. Therefore, this result should be interpreted with caution. The marginal bone level changes were examined already from the fixture installation. The major bone loss was found between fixture installation and baseline. This bone loss was several times greater than the bone loss between the baseline and the 1‐year follow‐up. The total bone loss during the observation period did not differ significantly between the systems, but they had different resorption patterns. The bone loss in the upper jaw between baseline and 1‐year follow‐up was 0.22 ± 0.14 and 0.03 ± 0.09 mm for the Astra Tech and Brånemark implants, respectively. In the lower jaw, the loss was ‐0.31 for both systems. The frequency of plaque accumulation and bleeding on probing did not differ between the implant systems. Conclusions: Abutment connection with Astra Tech implants was simpler than the corresponding surgery with Brånemark System implants and the survival rate of Astra Tech implants was higher than that of Brånemark system implants.
First and Second Branchial Arch Syndrome: Aspects on the Embryogenesis, Elucidations, and Rehabilitation Using the Osseointegration Concept
Authors: Granström Gosta , Jacobsson Catharina 
Published: April 2007

ABSTRACT Background: The Osseointegration concept has dramatically changed the possibility of rehabilitating patients with craniofacial defects due to branchial arch syndromes. Purpose: This article describes some problems related to the investigative routines and rehabilitation of individuals with malformations of the first and second branchial arches of the craniofacial region. Animal model systems have increased the knowledge of basic embryonic processes that can explain the extent of the malformations. Though most clinical first and second branchial arch syndromes are likely to be caused by sporadic mutations, inherited syndromes occur and also teratogenically induced syndromes are known. Prenatal diagnosis ruling out heredity and exogenous influence seems possible in the future. The possibility of preventing and alleviating fulminant syndromes prenatally also could be conceivable in the future. Patients and Methods: The rehabilitation process starts early after birth and should involve a team of specialists including clinical geneticists, pediatricians, audiologists, plastic surgeons, maxillofacial surgeons, otosurgeons, anaplastologists, speech pathologists, pedodontists, and orthodontists. With the development of the Osseointegration concept in which craniofacial prostheses and hearing aids can be adapted on implants anchored in the craniofacial skeleton, a new field in the rehabilitation of these malformations has opened. Results: Important aspects in the use of the Osseointegration concept include determination of the lowest age for implant surgery, accessibility of adequate bone for implants, the growth of the craniofacial skeleton during childhood, and the possibility for the patient and his or her parents to care for the skin penetration. Adverse tissue reactions, durability of craniofacial prostheses, and the possibility of unknown adverse reactions to metal implants in the body over a long time are other aspects of concern. Conclusions: Patients with branchial arch syndromes benefit from a well‐planned multidisciplinary rehabilitation process in which osseointegrated bone‐anchored hearing aids and bone‐anchored ear prostheses can be useful tools.
Clinical Experiences of Implant‐Supported Prostheses with Laser‐Welded Titanium Frameworks in the Partially Edentulous Jaw: A 5‐Year Follow‐up Study
Authors: Örtorp Anders , Jemt Torsten 
Published: April 2007

ABSTRACT Background: Titanium frameworks have been used in the endentulous implant patient for the last 10 years. However, knowledge of titanium frameworks for the partially dentate patient is limited. Purpose: To report the 5‐year clinical performance of implant‐supported prostheses with laser‐welded titanium frameworks in the partially edentulous jaw. Materials and Methods: A consecutive group of 383 partially edentulous patients were, on a routine basis, provided with fixed partial prostheses supported by Brånemark implants in the mandible or maxilla. Besides conventional frameworks in cast gold alloy, 58 patients were provided with titanium frameworks with three different veneering techniques, and clinical and radiographic 5‐year data were collected for this group. Results: The overall cumulative survival rate was 95.6% for titanium‐framework prostheses and 93.6% for implants. Average bone loss during the follow‐up period was 0.4 mm. The most common complications were minor veneering fractures. Loose and fractured implant screw components were fewer than 2%. An observation was that patients on medications for cardiovascular problems may lose more implants than others (p <.05). Conclusions: The clinical performance of prostheses with implant‐supported laser‐welded titanium frameworks was similar to that reported for conventional cast frames in partially edentulous jaws. Low‐fusing porcelain veneers also showed clinical performance comparable to that reported for conventional porcelain‐fused‐to‐metal techniques.
Anchorage of Titanium Implants with Different Surface Characteristics: An Experimental Study in Rabbits
Authors: Gotfredsen Klaus , Berglundh Tord , Lindhe Jan 
Published: April 2007

ABSTRACTPurpose:To compare the anchorage of titanium implants with different surface roughness and topography and to examine histologically the peri‐implant bone after implant removal.Materials and Methods:Screw implants with five different surface topographies were examined: (1) turned (“machined”), (2) TiO2‐blasted with particles of grain size 10 to 53 μm; (3) TiO2‐blasted, grain size 63 to 90 μm; (4) TiO2‐blasted, grain size 90 to 125 μm; (5) titanium plasma‐sprayed (TPS). The surface topography was determined by the use of an optical instrument. Twelve rabbits, divided into two groups, had a total of 120 implants inserted in the tibiae. One implant from each of the five surface categories was placed within the left tibia of each rabbit. By a second operation, implants were installed in the right tibia, after 2 weeks in group A and after 3 weeks in group B. Fluorochrome labeling was performed after 1 and 3 weeks. Removal torque (RMT) tests of the implants were performed 4 weeks after the second surgery in group A and 9 weeks after the second surgery in group B. Thus, in group A, two healing groups were created, representing 4 and 6 weeks, respectively. The corresponding healing groups in group B were 9 and 12 weeks. The tibiae were removed, and each implant site was dissected, fixed, and embedded in light‐curing resin. Ground sections were made, and the peri‐implant bone was analyzed using fluorescence and light microscopy.Results:The turned implants had the lowest Sa and Sy values, whereas the highest scores were recorded for the TPS implants. The corresponding Sa and Sy values for the TiO2‐blasted implants were higher when a larger size of grain particles had been used for blasting. At all four observation intervals, the TPS implants had the highest and the turned implants the lowest RMT scores. The differences between the various TiO2‐blasted implants were, in general, small, but the screws with the largest Sa value had higher RMT scores at 6, 9, and 12 weeks than implants with lower Sa values.The histologic analysis of the sections representing 6, 9, and 12 weeks revealed that fractures or ruptures were present in the marginal, cortical peri‐implant bone. In such sections representing the TPS and TiO2‐blasted implant categories, ruptures were frequently found in the zone between the old bone and the newly formed bone, as well as within the newly formed bone.Conclusions:The present study demonstrated that a clear relation exists between surface roughness, described in Sa values, and implant anchorage assessed by RMT measurements. The anchorage appeared to increase with the maturation of bone tissue during healing.
Proposed Method for the Standardized Measurement of Marginal Bone Height on Periapical Radiographs with the Brånemark System®
Authors: Galasso Luigi 
Published: April 2007

ABSTRACTBackground:Strict criteria have been stipulated to evaluate success and failure of dental implants. Periapical radiographs are considered an important means of evaluation. However, there is a lack of standardized and reproducible readily available methods to carry this out.Purpose:The purpose of this article is to describe the manufacturing and clinical use of a simple device that enables the clinician to take parallel and reproducible periapical radiographs of dental implants.Materials and Methods:Commercially available implant prosthetic components and film holder for periapical radiographs were modified and used clinically.Results:Clinically, the device works effectively and does not require significantly more time.Conclusions:The described device is a simple appliance with an uncomplicated method to overcome problems with taking parallel and reproducible radiographs of dental implants, which is especially important when measuring marginal bone height.
Implant‐Abutment Interface: Biomechanical Study of Flat Top versus Conical
Authors: Hansson Stig 
Published: April 2007

ABSTRACT Background: Overloading has been identified as a primary factor behind dental implant failure. The peak bone stresses normally appear in the marginal bone. The anchorage strength is maximized if the implant is given a design that minimizes the peak bone stress caused by a standardized load. Clinical studies have shown that it is possible to obtain a marginal bone level close to the crest of the implant. Different implant systems make use of different designs of the implant‐abutment interface. Different implant‐abutment interfaces imply that the functional load is distributed in different ways upon the implant. According to Saint‐Venant's principle, this will result in different stress patterns in the marginal bone when this reaches levels close to the implant crest. Purpose: One aim of the study was to theoretically investigate if a conical implant‐abutment interface gives rise to a changed stress pattern in the marginal bone, as compared to a flat top interface, for an axially loaded mandibular titanium implant, the neck of which is provided with retention elements giving effective interlocking with the bone. Further aims were to investigate if the way in which the axial load is distributed on the flat top and on the inner conus respectively affects the stress pattern in the marginal bone. The pertinent stress was considered to be the bone‐implant interfacial shear stress. It was assumed that the marginal bone reached the level of the implant–abutment interface. Method: The investigation was performed by means of axisymmetric finite element analysis. Results: The conical implant‐abutment interface of the type studied brought about a decrease in the peak bone‐implant interfacial shear stress as compared to the flat top interface of the type studied. This peak interfacial shear stress was located at the top marginal bone for the flat top implant‐abutment interface whereas it was located more apically in the bone for the conical implant‐abutment interface. The way in which the axial load was distributed on the flat top and on the inner conus respectively affected the peak interfacial shear stress level. Conclusion: The design of the implant‐abutment interface has a profound effect upon the stress state in the marginal bone when this reaches the level of this interface. The implant with the conical interface can theoretically resist a larger axial load than the implant with the flat top interface.
Measurements Comparing the Initial Stability of Five Designs of Dental Implants: A Human Cadaver Study
Authors: O'Sullivan Dominic , Sennerby Lars , Meredith Neil 
Published: April 2007

ABSTRACT Background: A number of different dental implant designs are currently in clinical use. A successful outcome of implant placement is thought, at least in part, to be due to the primary stability of an implant after placement. Few data are available for comparing the primary stability characteristics of different implant designs. Purpose: This investigation compared the primary stability of five types of endosseous dental implant of varying geometry and surface topography. Materials and Methods: Comparison was made between a standard threaded commercially pure titanium implant (Nobel Biocare AB, Göteborg, Sweden), the Mark II self‐tapping implant (Nobel Biocare AB, Göteborg, Sweden), the Mark IV tapered self‐tapping implant (Nobel Biocare AB, Göteborg, Sweden), the Astra Tioblast (AstraTech AB, Mölndahl, Sweden), and the 3i Osseotite (3I [Implant Innovations Incorporated], Palm Beach, Florida, USA). Fifty‐two fixtures were placed in the maxillary bone of nine unembalmed human cadavers. Implant stability as a function of peak insertion torque and resonance frequency values was recorded for each fixture site after placement. Removal torque was also measured 1‐hour postinsertion. Assessment of bone quality at each site was made. Results: All of the implants tested demonstrated good primary stability in type 2 and 3 bone. The Standard, Mark II, Osseotite, and Tioblast were less stable when placed into bone type 4. The Mark IV implants appeared to maintain a high primary stability even in Type 4 bone. Conclusion: When looking across all bone qualities, the Mark IV implant develops a significantly higher insertion torque than the Standard, Mark II, and Osseotite implant types, and a significantly higher resonance frequency value than the Standard implant, indicating a higher interfacial stiffness at the implant–bone interface.
Influence of Prosthesis Material on the Loading of Implants That Support a Fixed Partial Prosthesis: In Vivo Study
Authors: Duyck Joke , Van Oostenvyck Hans , Vander Sloten Jos , De Cooman Michel , Puers Robert , Naert Ignace 
Published: April 2007

ABSTRACT Background: Since loading is increasingly believed to be a determining factor in the treatment outcome with oral implants, there is a need to expand the knowledge related to the biomechanics of oral implants and its influencing factors. Purpose: The aim of this study was to investigate the influence of prosthesis material on the distribution and magnitude of load on oral implants carrying a fixed partial prosthesis by in vivo quantification and qualification of this load. Methods: Eight patients with in total nine three‐unit fixed partial prostheses on three implants and three patients with in total four two‐unit fixed partial prostheses on two implants were selected. Both metal and acrylic resin prostheses were made. Strain gauged abutments were used to measure the load on the supporting implants during controlled load application of 50 N on several positions along the occlusal surface of the prostheses and during maximal biting in maximal occlusion. Additional tests were conducted when the three‐unit prostheses were supported only by two implants, thereby creating an extension pontic. Results: A significantly better distribution of bending moments with the metal prostheses in comparison to the acrylic resin prostheses was observed in the case of the three‐unit prostheses on two implants. No other difference in load or load distribution with the different prosthesis materials was noted. Conclusion: The clinical significance of the study reveals an increased risk for bending overload of the implants that are closest to the point of load application only in the case of acrylic resin long span prostheses or acrylic resin prostheses with extensions.
Identification of Bone Morphogenetic Proteins 2 and 4 in Commercial Demineralized Freeze‐dried Bone Allograft Preparations: Pilot Study
Authors: Li Huika , Pujic Zac , Xiao Yin , Artold P. Mark 
Published: April 2007

ABSTRACT Background: Demineralized freeze‐dried bone allografts (DFDBAs) have been proposed as a useful adjunct in periodontal therapy to induce periodontal regeneration through the induction of new bone formation. The presence of bone morphogenetic proteins (BMPs) within the demineralized matrix has been proposed as a possible mechanism through which DFDBA may exert its biologic effect. However, in recent years, the predicability of results using DFDBA has been variable and has led to its use being questioned. One reason for the variability in tissue response may be attributed to differences in the processing of DFDBA, which may lead to loss of activity of any bioactive substances within the DFDBA matrix. Therefore, the purpose of this investigation was to determine whether there are detectable levels of bone morphogenetic proteins in commercial DFDBA preparations. Methods: A single preparation of DFDBA was obtained from three commercial sources. Each preparation was studied in triplicate. Proteins within the DFDBA samples were first extracted with 4M guanidinium HCI for seven days at 40 degrees Celsius and the residue was further extracted with 4M guanidinium HCL/EDTA for seven days at 40 degrees celsius. Two anti‐human BMP‐2 and ‐4 antibodies were used for the detection of the presence of BMP's in the extracts. Results: Neither BMP‐2 nor BMP‐4 was detected in any of the extracts. When recombinant human BMP‐2 and ‐4 were added throughout the extraction process of DFDBA extraction, not only were intact proteins detected but smaller molecular weight fragments were also noted in the extract. Conclusions: These results indicate that all of the DFDBA samples tested had no detectable amounts of BMP‐2 and ‐4. In addition, an unknown substance present in the DFDBA may be responsible for degradation of whatever BMPs might be present.
Long‐term Follow‐up of Severely Atrophic Edentulous Mandibles Reconstructed with Short Branemark Implants
Authors: Friberg Bertil , Gröndahl Kerstin , Lekholm Ulf , Brånemark Per‐Ingvar 
Published: April 2007

ABSTRACT Background: Oral implant treatment (Brånemark System) of edentulous mandibles has been presented in numerous studies. However, with regard to the severely atrophic lower jaw, no long‐term follow‐up studies with solely short implants are available. Purpose: The purpose of the present investigation was to retrospectively follow the long‐term treatment outcome of patients with severely resorbed edentulous mandibles being subjected to oral implant placement with short (6–7 mm) Brånemark implants. Materials and Methods: A total of 247 standard (7 mm long, 3.75 mm) and 13 wide (6 mm long, 5 mm) implants were inserted in 49 patients, all of whom exhibited severe resorption of edentate mandibles. Fixed implant‐supported prostheses were manufactured for 45 patients, whereas 4 patients received overdentures. The patients were followed for a mean period of 8 years (range, 1–14 yr). Results: Seventeen implants failed during the study period (cumulative implant survival rate 95.5% at 5‐yr and 92.3% at 10‐yr follow‐up). Implant‐supported constructions were worn continuously throughout the investigation by all study subjects. Marginal bone loss, measured after 1, 5, and 10 years of function, concurred with studies of Brånemark implants placed in more voluminous mandibles. No major clinical or construction complications occurred in the followed patients. Conclusions: The outcome of the present study showed that placement of short Brånemark implants without the use of bone grafting procedures for reconstruction of severely atrophic edentulous mandibles is a highly predictable treatment procedure.
Biologie Outcome of Single‐Implant Restorations as Tooth Replacements: A Long‐term Follow‐up Study
Authors: Naert Ignace , Koutsikakis George , Duyck Joke , Quirynen Marc , Jacobs Reinhilde , van Steenberghe Daniel 
Published: April 2007

ABSTRACT Background: The replacement of a single tooth or several teeth by means of single‐implant restorations is an increasingly used method that needs long‐term validation. Purpose: The goal of this study was to evaluate the outcome of single‐implant restorations by means of fixed restorations and to define the prognosis through marginal bone level estimations. Materials and Methods: From November 1986 to June 1998, 270 Brånemark implants (215 in the upper jaw) were installed in 219 patients (106 males). Both anterior and posterior sites were involved. Of the 263 single restorations, 28 were placed in private dental offices. The patients were followed until June 1999. Results: Twelve implants failed before or at abutment connection or within 6 months afterward. Only four implants failed later. The cumulative success rates were 93% for the implants and 96.5% for the restorations over a period of 11 years. The marginal bone loss during the first 6 months after abutment connection reached 0.71 mm and then dropped to 0.036 mm annually over a period of 10 years. Conclusions: Single‐implant restorations (Brånemark System) are a reliable treatment with a good long‐term prognosis. Failures were concentrated during the healing period and early loading phase.
Interaction of Force‐Fitting and Surface Roughness of Implants
Authors: Skalak Richard , Zhao Yihua 
Published: April 2007

ABSTRACT Background: Increased surface roughness may increase installation torque and thus appear to increase the initial stability of an implant. However, it is not immediately clear if the increased torque is attributable to an increase in the effective diameter of the implant or to increased resistance of the bone because of the greater roughness. Purpose: Force‐fitting stresses arise when an implant is placed into a predrilled hole of smaller‐diameter in bone. The purpose of this report is to discuss the interaction of force‐fitting stresses and surface roughness effects and to develop some general guidelines as to clinical procedures based on this theory. Materials and Methods: Solutions for the force‐fitting stresses are derived from well‐known equations of elasticity. Results: Substantial force‐fitting stresses on the order of several tens of MPa can be generated when a titanium cylinder is placed into a hole in bone, the diameter of which is only 100 m smaller. Conclusion: When a hole slightly smaller than the implant diameter is prepared for implant placement, force‐fitting stress increases installation torque and stability can be induced. Thus, large surface roughness of implants should not be viewed as an exclusive mechanism for providing a desirable level of initial fixity. Smaller roughness with the same mean diameter is equally effective.