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Åstrand, Per
Publications (10 of 14) Show all publications
Fermergard, R. & Åstrand, P. (2012). Osteotome Sinus Floor Elevation without Bone Grafts - A 3-Year Retrospective Study with Astra Tech Implants. Clinical Implant Dentistry and Related Research, 14(2), 198-205
Open this publication in new window or tab >>Osteotome Sinus Floor Elevation without Bone Grafts - A 3-Year Retrospective Study with Astra Tech Implants
2012 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 14, no 2, p. 198-205Article in journal (Refereed) Published
Abstract [en]

Background: The bone support for implants in the posterior part of the maxilla is often poor. This condition may be treated with augmentation of the maxillary sinus floor. The most common technique used is to elevate the sinus floor by inserting a bone graft through a window opened in the lateral antral wall. In 1994, a less-invasive technique using osteotomes was suggested by Summers. less thanbrgreater than less thanbrgreater thanPurpose: The aim of this study was to evaluate the clinical and radiographic outcome of implants placed in the posterior maxilla with the osteotome sinus floor elevation (OSFE) technique without grafting. less thanbrgreater than less thanbrgreater thanMaterials and Methods: The study population comprised 36 consecutive patients in whom 53 implants were inserted with the OSFE technique. The indication for sinus floor elevation was that the bone height below the maxillary sinus was considered to be 10 mm or less. less thanbrgreater than less thanbrgreater thanResults: The mean height of the alveolar process in the intended implant sites was 6.3 +/- 0.3 mm, and the mean elevation of the sinus floor was 4.4 +/- 0.2 mm. Two implants in edentulous patients were lost at the 1-year follow-up, and one more at the 3-year examination. The remaining 50 implants inserted were in function, giving a 3-year cumulative survival rate of 94%. Implants used in single-tooth replacements and in partially edentulous cases had a 100% survival rate. The marginal bone level at the time of loading of the implants was 0.1 +/- 0.04 mm below the reference point. One year later, the corresponding value was 0.5 +/- 0.06 mm. The mean bone loss between the two examinations was 0.4 +/- 0.05 mm. At the final examination after 3 years, the mean bone level was situated 0.6 +/- 0.09 mm below the reference point, indicating a nonsignificant change between 1 year and 3 years. less thanbrgreater than less thanbrgreater thanConclusions: The OSFE technique, without bone grafts, was found to produce predictable results in the treatment of 36 patients with restricted bone volume in the posterior part of the maxilla.

Place, publisher, year, edition, pages
Wiley-Blackwell, 2012
Keywords
Astra Tech implants, dental implants, osteotome, posterior maxilla, sinus floor elevation
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-76969 (URN)10.1111/j.1708-8208.2009.00254.x (DOI)000301980500004 ()
Note
Funding Agencies|Astra Tech Co.||Available from: 2012-04-27 Created: 2012-04-27 Last updated: 2017-12-07
Åstrand, P., Ahlqvist, J., Gunne, J. & Nilson , H. (2008). Implant Treatment of Patients with Edentulous Jaws: A 20-Year Follow-Up. Clinical Implant Dentistry and Related Research, 10(4), 207-217
Open this publication in new window or tab >>Implant Treatment of Patients with Edentulous Jaws: A 20-Year Follow-Up
2008 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 10, no 4, p. 207-217Article in journal (Refereed) Published
Abstract [en]

Background: Implant-supported prostheses are today often used in rehabilitation of partially or totally edentulous patients. Both patients and the dental profession often regard implant treatment as successful in a life perspective. Therefore, studies with a long-term follow-up are important.

Purpose: The aim was to investigate the outcome of implant treatment with fixed prostheses in edentulous jaws after 20 years, with special reference to survival rate of implants and prostheses and frequency of peri-implantitis.

Materials and Methods: The patient material was a group of patients treated in the early 1980s. The original patient group comprised the first 48 consecutive patients treated with implant-supported prostheses at Umea University. All patients were edentulous in one or two jaws. The patients had a mean age at the implant insertion of 54.3 years (range 40-74). At the planning of this study 20 years after treatment, 19 of the 48 patients were found to be deceased. Of the 29 patients still alive, 21 patients with altogether 23 implant-supported prostheses could be examined clinically and radiographically. All patients were treated ad modum Branemark (R) (Nobel Biocare AB, Goteborg, Sweden) with a two-stage surgical procedure. The implants had a turned surface. Abutment connections were performed 3 to 4 months after fixture insertion in the mandible, and after a minimum of 6 months in the maxilla. The prostheses were fabricated with a framework of gold alloy and acrylic artificial teeth.

Results: The 21 patients (with 23 implant prostheses) examined had at the time of treatment got 123 implants (27 in the upper jaw and 96 in the lower jaw) inserted. Only one of these implants had been lost (about 2 years after loading) giving a survival rate of 99.2%. Very small changes occurred in the marginal bone level. Between the 1 and 20-year examinations, the mean bone loss was 0.53 mm and the mean bone level at the final examination was 2.33 mm below the reference point.

Conclusions: This follow-up over two decades of implant-supported prostheses demonstrates a very good prognosis for the treatment performed. The frequencies of peri-implantitis, implant failures, or other complications were very small, and the original treatment concept with a two-stage surgery and a turned surface of the implants will obviously give very good results.

Keywords
Branemark implants, edentulous jaws, fixed complete prostheses, long-term follow-up
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-16121 (URN)10.1111/j.1708-8208.2007.00081.x (DOI)
Available from: 2009-01-08 Created: 2009-01-07 Last updated: 2017-12-14
Åstrand, P. & Klinge, B. (2008). Implantatsystem på den svenska marknaden. Tandläkartidningen, 100(4), 54-62
Open this publication in new window or tab >>Implantatsystem på den svenska marknaden
2008 (Swedish)In: Tandläkartidningen, ISSN 0039-6982, Vol. 100, no 4, p. 54-62Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-44693 (URN)77311 (Local ID)77311 (Archive number)77311 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Fermergard, R. & Åstrand, P. (2008). Osteotome sinus floor elevation and simultaneous placement of implants - A 1-year retrospective study with astra tech implants. Clinical Implant Dentistry and Related Research, 10(1), 62-69
Open this publication in new window or tab >>Osteotome sinus floor elevation and simultaneous placement of implants - A 1-year retrospective study with astra tech implants
2008 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 10, no 1, p. 62-69Article in journal (Refereed) Published
Abstract [en]

Background: The bone support for implants in the posterior part of the maxilla is often poor. This condition may be treated with augmentation of the maxillary sinus floor. The most common technique used is to elevate the sinus floor by inserting a bone graft through a window opened in the lateral antral wall, although less invasive techniques with osteotomes have been used since 1994. Purpose: The aim of this study was to evaluate the clinical and radiographic outcome of implants placed in the posterior maxilla with the osteotome sinus floor elevation (OSFE) technique without grafting. Materials and Methods: The study population comprised 36 consecutive patients in whom 53 implants were inserted with the OSFE technique. The indication for sinus floor elevation was that the bone height below the maxillary sinus was considered to be 10 mm or less. Results: The mean height of the alveolar process in the intended implant sites was 6.3 ± 0.3 mm, and the mean elevation of the sinus floor was 4.4 ± 0.2 mm. At the 1-year follow-up, two implants had been lost, both in edentulous patients. The remaining 51 implants inserted were in function, giving a 1-year cumulative survival rate of 96%. Implants used in single-tooth replacements and in partially edentulous cases had a 100% survival rate. The mean marginal bone level at the time of loading of the implants was 0.1 ± 0.04 mm below the reference point. One year later, the corresponding value was 0.5 ± 0.06 mm. The mean bone loss between the two examinations was 0.4 ± 0.05 mm. Conclusions: The OSFE technique, without bone grafts, was found to produce predictable results in the treatment of 36 patients with restricted bone volume in the posterior part of the maxilla. © 2007, Blackwell Publishing.

Keywords
Astra Tech implants, Dental implants, Osteotome, Posterior maxilla, Sinus floor elevation
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-46711 (URN)10.1111/j.1708-8208.2007.00062.x (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Engquist, B., Åstrand, P., Anzén, B., Engquist, E., Feldmann, H., Nord, P. G., . . . Svärdström, P. (2005). Simplified methods of implant treatment in the edentulous lower jaw: A 3-year follow-up report of a controlled prospective study of one-stage versus two-stage surgery and early loading. Clinical Implant Dentistry and Related Research, 7(2), 95-104
Open this publication in new window or tab >>Simplified methods of implant treatment in the edentulous lower jaw: A 3-year follow-up report of a controlled prospective study of one-stage versus two-stage surgery and early loading
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2005 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 7, no 2, p. 95-104Article in journal (Refereed) Published
Abstract [en]

Background: Interest in the use of one-stage surgery and immediate loading of oral implants has lately been increasing. Purpose: The aim of this study was to compare the 3-year results of one-stage surgery versus two-stage surgery, early loading versus loading after a 3-month healing period, and the use of one-piece implants versus the use of two-piece implants. Materials and Methods: The study included 108 patients with edentulous mandibles. Each patient was treated with four Brånemark System® implants (Nobel Biocare AB, Göteborg, Sweden) and with full fixed prostheses. Patients were consecutively treated and were distributed in four groups: group A (one-stage surgery), group B (control group with two-stage surgery), group C (one-piece implants), and group D (early loading). In groups A and B Brånemark Standard implants and standard abutments were used. In group C the conical one-piece Brånemark implant was used, and in group D the patients had Brånemark System Mk III implants together with multiunit abutments. All patients were observed for 3 years. Results: Of the 432 inserted implants, 24 were lost. Survival rates in the three experimental groups ranged from 93.2 to 93.3% whereas the survival rate in group B (the control group with two-stage surgery) was 97.5%. The differences between the groups were not statistically significant. The changes in marginal bone level were measured from fixture insertion to the final follow-up at 3 years. The bone loss in group D (early loading) was significantly less than in group B (the control group) whereas there were no differences in marginal bone change between the other groups. Conclusions: Early loading seemed to give good results in the anterior part of the mandible. The survival rate of the early-loaded implants did not significantly differ from that of implants inserted with the conventional two-stage procedure, but the mean marginal bone loss around the surviving implants was less with early loading. ©2005 BC Decker Inc.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-30827 (URN)16461 (Local ID)16461 (Archive number)16461 (OAI)
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2017-12-13
Åstrand, P., Engqusit, B., Dahlgren, S., Gröndal, K., Engquist, E. & Feldmann, H. (2004). Astra Tech and Brånemark system implants: A 5-year prospective study of marginal bone reactions. Clinical Oral Implants Research, 15(4), 413-420
Open this publication in new window or tab >>Astra Tech and Brånemark system implants: A 5-year prospective study of marginal bone reactions
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2004 (English)In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 15, no 4, p. 413-420Article in journal (Refereed) Published
Abstract [en]

This paper describes the 5-year results of a comparative study between Astra Tech and Brånemark system implants. The aim was to compare the systems primarily with regard to bone level changes, and also with regard to other variables of interest. Sixty-six patients with edentulous jaws were included in the study. Randomisation schedules were used to allocate the patients to the two implant systems. 184 Astra Tech implants with a titanium-blasted surface and 187 Brånemark implants with a turned surface were used. The implants were inserted with a two-stage technique and the insertion followed the routines for the respective implant system. All patients were provided with full-arch fixed bridges. All patients were followed up with clinical and radiographic examinations from fixture insertion to the 5-year follow-up. The total mean bone level change in the upper jaw between fixture insertion and the 5-year examination was - 1.74±0.45 mm at the Astra implants and - 1.98±0.21 at the Brånemark implants. The corresponding values for the lower jaw were - 1.06±0.19 for Astra and - 1.38±0.17 for Brånemark. The major postoperative changes of the marginal bone level took place between fixture insertion and baseline. During this period, there was also a different pattern of bone remodelling between the implant systems. Between baseline (prosthesis connection) and the 5-year examination, the marginal bone level changes were small, with no difference between the implant systems. The implant stability was examined with the supraconstructions removed. At the 5-year examination, the survival rate for Astra Tech implants was 98.4% and for the Brånemark implants it was 94.6%. The difference was not statistically significant.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-24738 (URN)10.1111/j.1600-0501.2004.01028.x (DOI)6989 (Local ID)6989 (Archive number)6989 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Hellem, S., Åstrand, P., Stenström, B., Engquist, B., Bengtsson, M. & Dahlgren, S. (2004). Implant treatment in combination with lateral augmentation of the alveolar process: A 3-year prospective study. Clinical Implant Dentistry and Related Research, 5, 233-240
Open this publication in new window or tab >>Implant treatment in combination with lateral augmentation of the alveolar process: A 3-year prospective study
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2004 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 5, p. 233-240Article in journal (Refereed) Published
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-24006 (URN)3561 (Local ID)3561 (Archive number)3561 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Engquist, B., Åstrand, P., Anzén, B., Dahlgren, S., Engquist, E., Feldmann, H., . . . Svärdström, P. (2004). Simplified methods of implant treatment in the edentulous lower jaw. Part II: Early loading. Clinical Implant Dentistry and Related Research, 6(2), 90-100
Open this publication in new window or tab >>Simplified methods of implant treatment in the edentulous lower jaw. Part II: Early loading
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2004 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 6, no 2, p. 90-100Article in journal (Refereed) Published
Abstract [en]

Background: Most implant treatment is performed with a two-stage surgical procedure. A disadvantage of these implant treatments is that they are time-consuming. Purpose: The aim of the present study was to evaluate the results of early loading in the edentulous mandible and to compare those results with treatment results of one-stage surgery followed by a healing period and with two-stage surgery. Material and Methods: The material comprises four treatment groups with a total of 108 patients with edentulous lower jaws and 432 implants. All patients were treated with Brånemark implants (Nobel Biocare AB, Gothenburg, Sweden) with a turned surface and fixed prostheses in the lower jaw, supported by four implants. The patients in group A were treated with a one-stage procedure, a two-piece implant, and a 3-month healing period before loading. Group B (control group) had a two-stage procedure, a two-piece implant, and a 3-month healing period. Group C had a one-stage procedure, a one-piece implant, and a 3-month healing period. Group D was treated with a one-stage surgical procedure, a two-piece implant, and early loading (within 3 weeks). All patients were provided with a Procera® Implant Bridge (Nobel Biocare) with a framework made by computer-assisted milling of one piece of pure titanium. All patients have been followed up for 1 year. Results: The survival rates were 93.2 to 93.3% in the experimental groups and 97.5% in the control group. The difference was not statistically significant. The measurements of the marginal bone level demonstrated a mean bone loss of 0.8 mm between fixture insertion and the 1-year examination in patients with early loading (group D) whereas the bone loss in patients who underwent a healing period before loading was 1.3 to 1.6 mm. The difference between the control group and the group with early loading was significant. Conclusions: Survival rates for patients treated with a one-stage procedure were lower than survival rates for patients treated according to a "classical concept," but the differences were not statistically significant. There was no difference between treatment results with one-piece and two-piece implants. The implant loss in patients with early loading was probably caused by overloading, and careful supervision of occlusal loading is recommended. Early loading gave significantly less marginal bone loss when compared with two-stage surgery.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-24004 (URN)3559 (Local ID)3559 (Archive number)3559 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2017-12-13
Engquist, B., Åstrand, P., Dahlgren, S., Engquist, E., Feldmann, H. & Gröndahl, K. (2002). Marginal bone reaction to oral implants: A prospective comparative study of Astra Tech and Brσnemark System implants. Clinical Oral Implants Research, 13(1), 30-37
Open this publication in new window or tab >>Marginal bone reaction to oral implants: A prospective comparative study of Astra Tech and Brσnemark System implants
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2002 (English)In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 13, no 1, p. 30-37Article in journal (Refereed) Published
Abstract [en]

In earlier studies of Astra Tech and Brσnemark System implants, high survival rates and small marginal bone changes have been demonstrated. The aim of this study was to compare the two systems, primarily with regard to marginal bone changes, but also with regard to other clinical variables of interest. The present paper describes the results after three years. Sixty-six patients were included in the study and randomly assigned to treatment with Astra Tech implants (n = 184) or Brσnemark System implants (n = 187). The marginal bone level was radiographically examined at fixture insertion, at abutment connection, at baseline (delivery of the prosthetic construction) and at 1- and 3-year follow-up examinations. Between fixture insertion and the baseline examination, the pattern of marginal bone resorption differed between the two systems. However, there was no significant marginal bone change between baseline and the 1-year examination or between the 1- and 3-year examinations. Nor were there any differences between the systems. The mean bone loss in the upper jaw between BL (baseline) and 3 years was 0.2▒0.3 mm for Astra Tech implants and 0.2▒0.1 mm for Brσnemark System implants. The corresponding figures for the lower jaw were 0.3▒0.2 mm and 0.2▒0.1 mm. The survival rate of Astra Tech implants was significantly higher (98.9%) than for Brσnemark System implants (95.2%). However, five of the nine implant losses in the Brσnemark group occurred in one patient. For that reason, this result must be interpreted with caution. The number of patients with implant losses did not differ significantly between the systems. Few complications were recorded up to 3 years.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-27751 (URN)10.1034/j.1600-0501.2002.130103.x (DOI)12495 (Local ID)12495 (Archive number)12495 (OAI)
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13
Åstrand, P., Engquist, B., Anzén, B., Bergendal, T., Hallman, M., Karlsson, U., . . . Rundcrantz, T. (2002). Nonsubmerged and submerged implants in the treatment of the partially edentulous maxilla.. Clinical Implant Dentistry and Related Research, 4(3), 115-127
Open this publication in new window or tab >>Nonsubmerged and submerged implants in the treatment of the partially edentulous maxilla.
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2002 (English)In: Clinical Implant Dentistry and Related Research, ISSN 1523-0899, E-ISSN 1708-8208, Vol. 4, no 3, p. 115-127Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Dental implants vary in design and surfaces. In addition, different surgical techniques have been used for implant insertion. The ITI Dental Implant System (Straumann AG, Waldenburg, Switzerland) has always required a one-stage technique, whereas the Brσnemark System (Nobel Biocare AB, Gothenburg, Sweden) requires a two-stage technique. PURPOSE: The aim of this study is to compare the outcome of fixed partial bridges in the maxilla supported by both ITI and Brσnemark implants in a split-mouth design. MATERIALS AND METHODS: Twenty-eight patients with a residual anterior dentition in the maxilla were included in this split-mouth study. The Brσnemark implants were used on one side and the ITI implants on the other side of the residual dentition according to a randomization procedure. A blocking size of four was used, giving equal probability of placing ITI or Brσnemark implants in the right or left side of the jaw. The surgical and prosthetic procedures followed the guidelines given by the manufacturers. The prosthetic treatment with the two-implant systems was performed at the same time, and for that reason the healing period was 6 months for both systems. The observation period for all patients was 1 year after loading. RESULTS: Two Brσnemark implants (in one patient) were lost before loading, and one ITI implant was lost 1 year after loading. There was no significant difference in survival rate. Radiographic examination of the bone level was performed at the time of delivery of the bridge and after 1 year. The mean marginal bone level at baseline was situated 1.9 mm from the reference point for the Brσnemark implants and 1.5 mm for the ITI implants. With regard to the insertion depth used, these bone levels indicate that bone loss had taken place before baseline. However, between baseline and the 1-year examination, there was no significant change of the marginal bone (0.2 +/- 0.08 mm at the Brσnemark implants and 0.1 +/- 0.11 mm at the ITI implants). The difference between results with the two implants was not statistically significant. Crater-form bone destructions were seen at some ITI implants, indicating periimplantitis. However, at only two implants were there clinical signs of periimplantitis. CONCLUSIONS: No significant difference in survival rate or in marginal bone change could be demonstrated between the two systems. At some ITI implants (18%), crater-form bone loss was observed.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-27610 (URN)12340 (Local ID)12340 (Archive number)12340 (OAI)
Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2017-12-13
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