bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atomic Force Microscopic Study of Commercially Available Implant Abutments
Authors: Sawase Takashi , Wennerberg Ann , Hallgren Carin , Miyamoto Ikuya , Albrektsson Tomas 
Published: April 2007

ABSTRACT Background: Clinical studies have reported a correlation between the surface roughness of implant abutments and the rate of supragingival and subgingival plaque formation. In order to maintain periimplant health, it is important to understand the relationship between abutment surface characteristics and plaque formation. Purpose: The aim of this study was to use high image resolution imaging techniques for analysis of implant abutment surface topography. Materials and Methods: Five commercially available implant abutments (Brånemark, Nobel Biocide, AB, Goteborg, Sweden, Astra, Astra Tech AB, Mondal, Sweden, IMZ, Friatec AG, Mannheim, Germany, Steri‐Oss, Denar Corp, Anaheim, Calif, USA, and POI, Kyocera Corp, Kyoto, Japan) were visually and quantitatively characterized using an atomic force microscope. Results: Statistical analysis by analysis of variance and Fishers's Protected Least Significant Differences showed significant differences (p<.05) between arithmetic mean deviation values of surface relative to the center plane (Sa). Power spectral density analysis also was effective as a spacing parameter. Sectional profiles measured the exact length, depth, or height of the specific features on the images. Conclusions: Within the limits of this study, the Brånemark, Astra and IMZ abutments displayed turning marks in x direction from the procedure. The Steri‐Oss abutment showed smoothest surface among the five abutments tested.
Bone Response to Implant‐Supported Frameworks with Differing Degrees of Misfit Preload: In Vivo Study in Rabbits
Authors: Jemt Torsten , Lekholm Ulf , Johansson Carina B. 
Published: April 2007

ABSTRACTPurpose:To study the bone response around implants placed in tibia of rabbits that supported misfitting superstructures secured with different degrees of preload.Materials and Methods:Twelve rabbits were provided with two terminal 10‐mm and one intermediate 7‐mm‐long implant in each tibia. After an integration time of about 9 weeks, nine of the animals received one control framework each (n = 9), designed with good fit to all three implants. In the other tibia of these animals, and in both tibias in the remaining three rabbits, test frameworks (n = 15) were connected with a vertical misfit of about 1 mm to the intermediate implant. The intermediate set screws were tightened with a torque ranging from 15 Ncm to 26 Ncm in the different test frameworks. The fascia and skin was then sutured back over the implants. After a loading period of 2 to 3 weeks, the animals were sacrificed, and histomorphometric measurements were made and correlated to the different levels of preload of the central implant.Results:The mean bone‐to‐metal contact for the three best consecutive threads of the central implant was 40% for both test and control sites (p > .05). Compared to the other regions of the implant thread, less bone‐to‐metal contact was found at the tip of the test implant threads in the low preload group (p < .05). However, the same relation was not observed in the high preload group. A significant correlation was observed between increasing degree of preload in the central screw joint and increasing bone‐to‐metal contact, most obviously noticed at the tip of the implant thread (p < .01).Conclusions:Misfit stress levels of clinical magnitudes do not seem to jeopardize osseointegration per se. On the contrary, clinical levels of preload stress seem to significantly promote bone remodeling at the tip of the implant thread.
Immediate Function of Brånemark Implants in the Esthetic Zone: A Retrospective Clinical Study with 6 Months to 4 Years of Follow‐up
Authors: Maló Paulo , Rangert Bo , Dvärsäter Lisbeth 
Published: April 2007

ABSTRACTBackground:Immediate implant function is a psychological benefit for the patient and makes a substantial reduction in treatment cost possible. Currently, immediate function using Brånemark implants has become an accepted alternative for complete‐arch fixed restorations in mandibles and for overdenture support for some other screw‐shaped implants. Clinical documentation is lacking for other applications.Purpose:The purpose of this study was to investigate a concept for immediate function of Brånemark implants supporting fixed prosthesis in the esthetic regions of the jaws.Materials and Methods:This retrospective clinical study included 49 consecutively treated patients with 94 implants supporting 54 fixed prostheses, all in esthetically critical regions: 23 of the prostheses were bridges, 14 in maxillae and 9 in mandibles; 31 of the prostheses were crowns, 22 in maxillae and 9 in mandibles. At surgery, the implant platform was positioned above the surrounding bone level and bicortical anchorage was the goal whenever possible. The minimum insertion torque for accepting the implant for immediate function was 32 Ncm. Provisional implant‐supported prostheses without occlusal contacts were delivered at time of surgery, and final prostheses with normal occlusion were delivered 5 months later.Results:Eighty‐five of the implants (90%) have passed the 1‐year and 40 (43%) the 2‐year follow‐ups, respectively. Two implants failed in one patient before the 6‐month follow‐up, and another two implants between the 6‐month and the 1‐year follow‐up, in two other patients, giving a cumulative survival rate of 96%. The average bone resorption was 0.8 mm after the first year as evaluated from 35 patients with readable radiographs. The failed implants were replaced after 3 to 4 months with immediate function; these were successful in all cases (not included in this study). The number of complications was small and did not differ in character from those normally encountered at implant treatment using a conventional protocol.Conclusions:The cumulative survival rate of 96% at 1 and 2 years indicates that immediate function of Brånemark implants used in the esthetic zone in both jaws can be a viable concept. All failures occurred in fresh extraction sites, and extra care is recommended to avoid situations with ongoing inflammation in these situations.
A Clinical, Radiographic, and Microbiologic Comparison of Astra Tech and Brånemark Single Tooth Implants
Authors: Puchades‐Roman Lorena , Palmer Richard M. , Palmer Paul J. , Howe Leslie C. , Ide M. , Wilson Ron F. 
Published: April 2007

ABSTRACT Background: The soft tissues around single tooth implants differ fundamentally from the gingiva around natural teeth. There are very limited data comparing soft tissues around different implant systems. Aim: To assess whether the design characteristics of dental implants, particularly the implant‐abutment junction, may affect the dimensions and health of the peri‐implant soft tissues and radiographic bone levels. Subjects and Method: Fifteen Astra Tech and 15 Brånemark single tooth implants that had been in function for a minimum of 2 years in 30 partially dentate subjects were examined for plaque accumulation, probing depth, and bleeding on probing and compared to contralateral healthy teeth. Standardized radiographs were taken to measure the most coronal bone to implant contact on the mesial and distal surfaces. In addition, samples of subgingival plaque were taken on paper points and examined by darkfield microscopy. Results: Significantly higher mean probing depths (p < .001) and higher mean percentage of spirochetes (p= .003) were found at implants compared to teeth. In this sample, the Brånemark implants had significantly higher probing depths than the Astra Tech implants (median and interquartile range: Astra Tech 2.7 mm [2–3], Brånemark 3.3 mm [3–3.7] p= .026) and the most coronal bone to implant contact was closer to the implant–abutment junction in the Astra Tech implants (Astra Tech 0.6 mm [0.2–0.9], Brånemark 1.6 mm [1.4–2.0]. p < .001). Conclusion: Although there were statistically significant differences between the two implant systems, the clinical differences were small and probably reflect differences in the biologic width in relation to the location and design of the implant‐abutment junction.
Augmentation of Exposed Implant Threads with Autogenous Bone Chips: Prospective Clinical Study
Authors: Widmark Göran , Ivanoff Carl‐Johan 
Published: April 2007

ABSTRACT Background: Autogenous bone chips can be harvested during drilling of implant sites and may be used as a graft material for bone augmentation and coverage of exposed implant threads. Purpose: The aim of this prospective study was to evaluate the possibility of augmenting exposed implant threads with autogenous bone chips. Materials and Methods: Twenty‐one consecutive patients treated with screw‐shaped oral implants with exposed threads due to buccal fenestration or marginal defects were augmented with autogenous bone harvested with a bone trap during drilling of the implant site. Both marginal (9 sites) and fenestration defects (12 sites), with 4 to 14 exposed implant threads, were registered clinically and with photography. The number of exposed implant threads was measured before and at second‐stage surgery 6 months after augmentation. Results: Complete bone coverage of the exposed implant threads was seen in 12 of the 21 implant sites. Six sites showed one to two remaining exposed threads, two showed about 40% coverage, and one showed flattening of the defect but with eight of nine exposed threads at 6 months follow‐up. The mean bone gain was 81% in patients with a marginal defect and 82% in patients with a fenestration defect. Conclusion: The results from this clinical study show that it is possible to gain bone over exposed implant threads by augmentation with autogenous bone chips. Conclusion It is concluded that it is possible to achieve coverage of exposed implant threads by augmentation with autogenous bone chips harvested during drilling of implant sites.
Re‐Establishment of the Atomic Composition and the Oxide Structure of Contaminated Titanium Surfaces by Means of Carbon Dioxide Laser and Hydrogen Peroxide: An In Vitro Study
Authors: Mouhyi Jaâfar , Sennerby Lars , Wennerberg Ann , Louette Pierre , Dourov Nicolas , van Reck Jack 
Published: April 2007

ABSTRACT Background: In clinical situations with peri‐implant bone resorption, re‐integration of the exposed implant surface is sometimes preferable, which requires a clean surface. Previous investigations have shown that cleaning of contaminated titanium surfaces using chemical and abrasive methods is difficult. Purpose: The aim of this investigation was to evaluate the efficacy of different combinations of chemical and physical methods (citric acid, hydrogen peroxide, and carbon dioxide [CO2] laser irradiation) for removal of contaminants and subsequent reconstruction of the surface oxide of intraorally contaminated titanium foils. Materials and Methods: Commercially pure titanium foils (99.6%, 55 mm in size) were contaminated by placement on dentures in volunteering patients, simulating a peri‐implantitis situation. The contaminated foils and clean control foils were treated by seven and six combinations of citric acid, hydrogen peroxide, and CO2 laser irradiation, respectively. The effect of the cleaning procedures was evaluated by x‐ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Results: The initial elemental composition of the contaminated foils was 70% carbon (C), 20% oxygen (O), 10% nitrogen (N), and only traces of titanium (Ti) (< 1%). One treatment proved to be more effective than the others: irradiations by 5‐second cycles of superpulsed CO2 laser at a power of 7 W, 10‐millisecond pulse width, and with an 80‐Hz frequency on a wet surface, followed by repeated application of supersaturated citric acid for 30 seconds, each time followed by rinsing with ultrapure water until all tissue remnants had been removed. Finally, hydrogen peroxide of 10‐mM concentration was added to the implant surface and evaporated by CO2 laser at the same settings. This treatment protocol resulted in 10% Ti, 45% O, 41% C, and 2 to 3% N, a composition comparable to that of unused foils:9% Ti, 40% O, 48% C, and traces of N and chlorine (CI). X‐ray photoelectron spectroscopy profiles showed that the thickness of the surface oxide was restored and even augmented with this protocol for treatment of contaminated titanium. Conclusion: A combination of citric acid, hydrogen peroxide, and CO2 laser irradiation seems to be effective for cleaning and reestablishment of the atomic composition and oxide structure of contaminated titanium surfaces.
One‐Year Prospective Evaluation of the Early Loading of Unsplinted Conical Brånemark Fixtures with Mandibular Overdentures Immediately following Surgery
Authors: Payne Alan G.T. , Tawse‐Smith Andrew , Kumara Rohana , Thomson W. Murray 
Published: April 2007

ABSTRACT Background: Prospective evaluation of the early loading of unsplinted Branemark implants with mandibular over‐dentures opposing conventional dentures is not evident in the implant‐related literature. Purpose: To clinically evaluate progressive and early loading of 20 unsplinted conical Brånemark implants in edentulous mandibles with overdentures. Materials and Methods: Ten edentulous patients all had two conical Brånemark implants placed in the anterior mandible with mandatory primary stability with bicortical anchorage. Ball abutment connection was performed simultaneously. Previously constructed conventional mandibular dentures were temporarily relined with tissue conditioner postoperatively and worn with moderation for the first 2 weeks to allow progressive loading. Early loading of the implants followed after 2 weeks, with inclusion of the respective matrices in the mandibular dentures, using a definitive reline procedure. Results: All patients successfully functioned with their mandibular implant overdentures from 2 to 52 weeks postoperatively. Mean marginal bone loss was within established criteria for success:0.22 mm (SD = 0.48 mm) mesially and 0.30 mm (SD = 0.39 mm) distally on the conical implants. Mobility tests using the Periotest instrument became more negative, although not at statistically significant levels. Difficulties in the management of the peri‐implant mucosa between surgery and loading at 2 weeks were observed in 40% of the patients. Conclusions: These preliminary 1‐year results show that successful early loading of unsplinted conical Brånemark implants with mandibular overdentures is possible.
Tilted Implants as an Alternative to Maxillary Sinus Grafting: A Clinical, Radiologic, and Periotest Study
Authors: Aparicio Carlos , Perales Pilar , Rangert Bo 
Published: April 2007

ABSTRACT Background: Owing to mechanical and anatomic difficulties, implant treatment in the atrophic maxilla represents a challenge. The maxillary sinus floor augmentation procedure is still not universally accepted because of its complexity and its unpredictability. Purpose: In this study, a combination of tilted and axial implants was used in patients with severely resorbed posterior maxillae as an alternative to sinus grafting. Materials and Methods: Twenty‐five patients were rehabilitated with 29 fixed partial prostheses supported by 101 Brånemark System implants. Fifty‐nine implants were installed in an axial and 42 in a tilted direction. The average follow‐up period was 37 months (range:21–87 mo post loading). Results: After 5 years, the implant cumulative success rate was 95.2% (survival: rate 100%) for the tilted implants and 91.3% (survival rate:96.5%) for the axial implants, and the prosthesis survival rate was 100%. At the fifth year, the average marginal bone loss was 1.21 mm for the tilted implants and 0.92 mm for the axial ones. The mean Periotest values (PTV) at loading time were ‐2.62 and ‐3.57, and after 5 years the PTVs were ‐4.73 and ‐5.00 for the tilted and the axial implants, respectively. During the follow‐up, all prostheses but two were mechanically stable, retightening of 18 abutment screws and of 5 gold screws in 14 prostheses was done, and fracture of two abutment screws and two occlusal surfaces was experienced. Conclusions: Results indicate that the use of tilted implants is an effective and safe alternative to maxillary sinus floor augmentation procedures.
Brånemark Implants and Osteoporosis: A Clinical Exploratory Study
Authors: Friberg Bertil , Ekestubbe Annika , Mellström Dan , Sennerby Lars 
Published: April 2007

ABSTRACT Background: Oral implant treatment on patients with poor jaw‐bone texture has shown increased failure rates in series of studies. Purpose: The purpose of the present study was to retrospectively follow patients with osteoporosis of the axial or appendicular skeleton, including the jaw bone, being subjected to oral implant treatment. The outcome of inserted implants, when using an adapted bone site preparation technique and extended healing periods, was evaluated. Materials and Methods: Based on data obtained from preoperative radiographs, patient medical history, and resistance of the jaw bone perceived during drilling, 14 of 16 patients were referred to the Osteoporosis Laboratory, Sahlgren University Hospital, Göteborg, Sweden, for bone density measurements. Two patients already had an established diagnosis of osteoporosis. Fourteen jaws in 13 patients (11 females, 2 males; mean age:68 yr) were subsequently subjected to oral implant treatment with a total of 70 implants (Brånemark System) of various designs. The mean follow‐up period was 3 years and 4 months (range:6 mo‐11 yr). Results: Osteoporosis of either the spine, the hip, or both regions was diagnosed in 14 patients, and osteopenia was diagnosed in 2 patients. Two implants failed, and the overall implant survival rate at the end of the study period was 97.0% for maxillae and 97.3% for mandibles. The marginal bone resorption at the 1‐year follow‐up concurs with the outcome of other studies, irrespective of the preoperative bone texture present. Conclusion: The outcome of the present study showed that implant placement in patients in whom the average bone density showed osteoporosis in both lumbar spine and hip as well as poor local bone texture may be successful over a period of many years.
Immediate Provisional for Single‐Tooth Implant Replacement with Brånemark System: Preliminary Report
Authors: Hui Edward , Chow James , Li Douglas , Liu Jerry , Wat Peter , Law Henry 
Published: April 2007

Abstract: Background: The success of osseointegrated implants ad modum Brånemark for single‐tooth restorations is documented. Future developments should aim at improving the benefits to patients by decreasing treatment time, minimizing surgical stages, and maximizing esthetic outcomes. Using knowledge from studies of immediate implant placement, one‐stage, immediate loading protocols, the authors developed the immediate provisional. Purpose: The purpose of this study was to develop a protocol to provide an immediate solution for restoring a single missing tooth in the esthetic zone. The protocol should be simple, predictable, cost effective, and allow the use of other techniques to improve esthetic outcome. Materials and Method: This prospective clinical study included 24 patients treated from August 1999 to October 2000. Single‐tooth implant replacement was done according to immediate provisional protocol. Thirteen of the 24 patients had immediate implant placement after tooth extraction. All implants were placed in the esthetic zone. During surgery, emphasis was placed on obtaining primary stability by achieving bicortical anchorage and maximum insertion torque of at least 40 Ncm. CeraOne (Nobel Biocare) abutments were used, and provisional crowns were fabricated immediately before wound closure. The occlusion was protected by adjacent teeth. Results: Within the follow‐up period of between 1 month and 15 months, all fixtures in the 24 patients were stable. Crestal bone loss greater than one thread‐width was not detected. The esthetic result was considered satisfactory by all patients. Conclusions: The implant placement and restoration protocol used in this study showed promising initial results for both the immediate implant and healed extraction site groups. The desirable goals of patient satisfaction, excellent esthetic outcomes, and no increase in treatment cost were achieved in this protocol. Further studies to elucidate the potential of the immediate provisional protocol are justified.
Histologic Analysis of Clinical Biopsies Taken 6 Months and 3 Years after Maxillary Sinus Floor Augmentation with 80% Bovine Hydroxyapatite and 20% Autogenous Bone Mixed with Fibrin Glue
Authors: Hallman Mats , Lundgren Stefan , Sennerby Lars 
Published: April 2007

Abstract: Background: Bovine hydroxyapatite (Bio‐Oss®, Geistlich Pharmaceutical, Wollhausen, Switzerland) has been suggested to be used in maxillary sinus floor augmentation procedures prior to or in conjunction with implant placement. However, the long‐term histologic fate of this material is not well understood. Purpose: The aim with this study was to histologically evaluate the tissue response in patients to a mixture of bovine hydroxyapatite (BH), autogenous bone, and fibrin glue 6 months and 3 years after a maxillary sinus floor augmentation procedure. Materials and Method: Biopsies were taken from a group of 20 consecutive patients 6 months (n = 16) and 3 years (n = 12) after maxillary sinus floor augmentation with a mixture of BH (80%), autogenous bone (20%), and fibrin glue and prepared for histologic analysis. Results: Light microscopy and morphometry from biopsies taken after 6 months showed various amounts of mineralized bone tissue. The specimen area was occupied by 54.1 ± 12.6% nonmineralized tissue, followed by 21.2 ± 24.5% lamellar bone, 14.5 ± 10.3% BH particles, and 10.2 ± 13.4% woven bone. The nonmineralized tissue seen in bone‐forming areas consisted of a loose connective tissue, rich with vessels and cells. There were no signs of resorption of the BH particles. The lamellar bone appeared to have originated from the recipient site and was seldom in contact with the BH particles. After 3 years, the nonmineralized tissue area had decreased to 36.0 ± 19.0% (p > .05) and consisted mainly of bone marrow tissue. The surface area of lamellar bone had increased to 50.7 ± 22.8% (p > .05), and there was almost no immature bone. The mean specimen area occupied by BH particles, was 12.4 ± 8.7% and had not changed from 6 months (not significant). Moreover, the sizes of the particles were similar after 6 months and 3 years. The degree of BH particle–bone contact had increased from 28.8%± 19.9% after 6 months to 54.5 ± 28.8% after 3 years (p > .05). Conclusion: Histology of specimens from maxillary sinuses augmented with 80% BH particles, 20% autogenous bone, and fibrin glue showed a positive bone tissue response after 6 months and 3 years after augmentation of the maxillary sinus floor prior to implant placement in a group fo 20 patients. The bone surrounding and in contact with the BH particles after 6 months was mainly immature woven bone, which with time was replaced by mature lamellar bone filling the interparticle space as observed in the 3‐year specimens. Moreover, bone‐integrated BH particles seem to be resistant to resorption. The results indicate that the procedure may be considered when only small amounts of intraoral autogenous bone graft are available.