Patricia Miranda Burgos | University of Gothenburg (original) (raw)

Papers by Patricia Miranda Burgos

Anticancer Research, 2019

Background: Oral leukoplakia (OL) is a potentially malignant oral mucosal disorder. A casual asso... more Background: Oral leukoplakia (OL) is a potentially malignant oral mucosal disorder. A casual association between OL, oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) infection has been suggested, but no conclusive evidence has been presented. p16, a tumoursuppressor protein, is used as a surrogate marker for HPV infection. The aim of this study was to investigate how overexpression of p16 correlates with HPV infection in OL and in OSCC. Patients and Methods: Seventy-four patients with OL and 13 with OSCC with p16 overexpressed, were analyzed by immunohistochemistry visualizing p16 and a real-time polymerase chain reaction (

International Journal of Oral and Maxillofacial Surgery, 2007

The aim of the study was to compare the integration and implant stability of turned and oxidized ... more The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p < 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.

Clinical Implant Dentistry and Related Research, Mar 1, 2003

Background: An increased number of publications report that one-stage surgery and immediate/early... more Background: An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients. Purpose: The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading. Materials and Methods: Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System® TiUnite™, Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry. Results: Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 ± 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 ± 10.5% and a mean bone area value of 79.1 ± 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 + 0.1% and 84.9 ± 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 ± 10.6% and 77.1 ± 6.8%, respectively. Conclusions: The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.

Clinical Oral Implants Research, 2004

Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery, Jan 13, 2017

The main objective of the present study was to assess the accuracy of two- and three-dimensional ... more The main objective of the present study was to assess the accuracy of two- and three-dimensional prediction techniques in orthognathic surgery. It was also a test of the very planning sequence. The scientific question was how well does the software support the surgeon in his way to find the perfect correction of the facial appearance while normalizing the occlusion? Thirty patients with a class III occlusion were included in this prospective study. Surgical planning with both techniques were undertaken for all patients. Surgery was performed according to the two-dimensional technique. The cephalometric measurements from two-dimensional and three dimensional predictions were compared with the postoperative results at the 12 months follow-up respectively. Together with an analysis of tracing error, placements of 2020 markers, 1860 measurements and 1280 comparisons was performed. The analysis showed an equally high accuracy for the studied techniques. The highest accuracy was found in ...

Clinical Implant Dentistry and Related Research, Sep 1, 2008

Background: Previous studies have shown the formation of more bone contacts with a moderately rou... more Background: Previous studies have shown the formation of more bone contacts with a moderately rough and porous titanium surface, created by anodic oxidation, as compared with nonmodified turned titanium control surfaces. The mechanisms leading to a stronger bone response to oxidized titanium are not well understood.

Aim Previous rabbit studies demonstrated higher affinity for bone formation at implant threads wi... more Aim Previous rabbit studies demonstrated higher affinity for bone formation at implant threads with furrows to threads without furrows. The present animal study was undertaken to study the bone tissue response and stability of oxidized titanium implants with 80, 110 and 160 μm wide furrows added on one thread flank. Materials and methods Ninety-six (96) threaded titanium implants, 3.75 mm in diameter and 7 mm long (TiUnite™, MKIII, Nobel Biocare AB, Gothenburg, Sweden), were manufactured with 70 μm deep and either 80 (S0), 110 (S1) or 160 (S2) μm wide furrows or no furrows (controls). The implants were installed in the distal femoral condyle and the tibial methaphysis of 12 rabbits. Six weeks later the implants were subjected to resonance frequency analysis (RFA) and removal torque (RTQ) tests, after ground sections were manufactured for light microscopy. Results A significantly increased (22%) stability of S1 implants in femoral sites compared with control implants was found. RFA s...

Background: Osseointegrated titanium implants are routinely used in clinical denstistry as anchor... more Background: Osseointegrated titanium implants are routinely used in clinical denstistry as anchorage units for dental prostheses. Although the overall clinical results are good, there are clinical situations when an optimized implant healing is desirable, for instance in order to shorten healing periods and to allow immediate loading. Aims: The present work was undertaken to study the influence of some microand macroscopical surface modifications on the integration and stability of titanium implants in bone. In addition, the aim was also to study the influence of a bone growth factor and autogenous bone grafts on implant healing in bone defects. Materials & Methods: The thesis is based on five experimental studies using a total of 12 mongrel dogs and 39 New Zealand White rabbits. In total, 327 screw-shaped implants were evaluated with histology and biomechanical tests. The implants had either a turned surface or had been treated with anodic oxidation to create a porous surface struc...

The International journal of oral & maxillofacial implants

Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of aut... more Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of autogeneic bone grafts or bovine bone mineral (BBM) combined with a space-making barrier enhances bone augmentation compared with a barrier alone. Sixteen rabbits were studied. In each rabbit, 2 titanium cylinders, each with 1 titanium lid, were placed subcutaneously in perforated slits made in the cortical bones, with their open ends facing the parietal bones. One cylinder was left empty and the other was filled with either autogeneic skull bone chips or BBM. Bone labels were injected after 4 and 11 weeks. After 12 weeks, the animals were sacrificed to obtain ground sections for histology and histomorphometry. Significantly more tissue was augmented in the 2 test groups than in the control group. Most of the autografts were resorbed, leaving only minute amounts in the upper third of the cylinders. Slender new bone trabeculae were distributed mainly from the contiguous bone plate that had n...

OSSEOINTEGRATION

Aim Previous studies have shown a preference for bone formation in macroscopic furrows as compare... more Aim Previous studies have shown a preference for bone formation in macroscopic furrows as compared to other parts of the implant surface. The aim of the study was to describe the early events of bone integration of furrowed oxidized titanium implants ...

eugenol.com

This PhD thesis represents number 32 in a series of investigations on implants, hard tissue and t... more This PhD thesis represents number 32 in a series of investigations on implants, hard tissue and the locomotor apparatus originating from the Department of Biomaterials/Handicap Research, Institute for Surgical Sciences at Göteborg University, Sweden.

International Journal of Oral and …, 2003

The International journal of oral & maxillofacial implants, 2003

PURPOSE Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether us... more PURPOSE Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of autogeneic bone grafts or bovine bone mineral (BBM) combined with a space-making barrier enhances bone augmentation compared with a barrier alone. MATERIALS AND METHODS Sixteen rabbits were studied. In each rabbit, 2 titanium cylinders, each with 1 titanium lid, were placed subcutaneously in perforated slits made in the cortical bones, with their open ends facing the parietal bones. One cylinder was left empty and the other was filled with either autogeneic skull bone chips or BBM. Bone labels were injected after 4 and 11 weeks. After 12 weeks, the animals were sacrificed to obtain ground sections for histology and histomorphometry. RESULTS Significantly more tissue was augmented in the 2 test groups than in the control group. Most of the autografts were resorbed, leaving only minute amounts in the upper third of the cylinders. Slender new bone trabeculae were distributed mainly fro...

Clinical Implant Dentistry and Related Research, 2005

ABSTRACTBackground: The influence of thread design at the millimeter level and surface topography... more ABSTRACTBackground: The influence of thread design at the millimeter level and surface topography at the micrometer level on bone integration and the stability of dental implants have been studied extensively. However, less is known about the influence of implant structures in the range of 50 to 200 μm.The influence of thread design at the millimeter level and surface topography at the micrometer level on bone integration and the stability of dental implants have been studied extensively. However, less is known about the influence of implant structures in the range of 50 to 200 μm.Purpose: The present in vivo investigation was undertaken to study if bone formation and implant stability were influenced by 110 (S1) and 200 (S3) μm-wide and 70 μm-deep grooves positioned at a thread flank of oxidized titanium implants.The present in vivo investigation was undertaken to study if bone formation and implant stability were influenced by 110 (S1) and 200 (S3) μm-wide and 70 μm-deep grooves positioned at a thread flank of oxidized titanium implants.Materials and Methods: Eighteen rabbits and oxidized titanium implants (3.75 mm in diameter and 7 mm long) were used in the study. Nine rabbits received three control implants and three test implants with a 110 μm-wide groove added to one thread flank. The remaining nine rabbits received three control implants and three test implants with a 200 μm-wide groove. The animals were followed for 6 weeks. Removal torque (RTQ) tests were applied to two of the implants in each leg. The remaining implant per leg was retrieved for histology. The degree of bone fill within the grooves and corresponding bone formation at the opposing surfaces, the bone area within the threads, and the degree of bone-implant contact were calculated for each implant.Eighteen rabbits and oxidized titanium implants (3.75 mm in diameter and 7 mm long) were used in the study. Nine rabbits received three control implants and three test implants with a 110 μm-wide groove added to one thread flank. The remaining nine rabbits received three control implants and three test implants with a 200 μm-wide groove. The animals were followed for 6 weeks. Removal torque (RTQ) tests were applied to two of the implants in each leg. The remaining implant per leg was retrieved for histology. The degree of bone fill within the grooves and corresponding bone formation at the opposing surfaces, the bone area within the threads, and the degree of bone-implant contact were calculated for each implant.Results: The histologic analyses revealed an affinity for bone formation within the grooves. The RTQ tests showed that the peak RTQ was approximately 30% higher for the S1 implants compared with control implants without a groove. The difference was statistically significant (p < .05) for tibial and pooled implants. A similar but smaller and not statistically significant effect, approximately 8%, was measured for the S3 implants. The histomorphometric measurements confirmed the observed affinity of bone for the grooves. For S1 implants, 78.7 ± 15.8% of the grooves were filled with bone, whereas only 46.2 ± 27% of the corresponding flank surface showed the presence of bone (p < .05). The corresponding figures for S3 and control implants were 72.7 ± 25.1% and 48.5 ± 13.6%, respectively (p < .05). The degrees of bone-implant contact and bone area within the threads were similar for test and control implants.The histologic analyses revealed an affinity for bone formation within the grooves. The RTQ tests showed that the peak RTQ was approximately 30% higher for the S1 implants compared with control implants without a groove. The difference was statistically significant (p < .05) for tibial and pooled implants. A similar but smaller and not statistically significant effect, approximately 8%, was measured for the S3 implants. The histomorphometric measurements confirmed the observed affinity of bone for the grooves. For S1 implants, 78.7 ± 15.8% of the grooves were filled with bone, whereas only 46.2 ± 27% of the corresponding flank surface showed the presence of bone (p < .05). The corresponding figures for S3 and control implants were 72.7 ± 25.1% and 48.5 ± 13.6%, respectively (p < .05). The degrees of bone-implant contact and bone area within the threads were similar for test and control implants.Conclusion: It is concluded that 110 and 200 μm-wide and 70 μm-deep grooves at oxidized implant surfaces stimulated bone to preferentially form within and along the groove in the rabbit model. The 110 μm-wide groove was shown to increase the resistance to shear forces significantly. It is suggested that implants with such a groove may be one way to optimize implant stability in suboptimal clinical conditions.It is concluded that 110 and 200 μm-wide and 70 μm-deep grooves at oxidized implant surfaces stimulated bone to preferentially form within and along the groove in the rabbit model. The 110 μm-wide groove was shown to increase the resistance to shear forces significantly. It is suggested that implants with such a groove may be one way to optimize implant stability in suboptimal clinical conditions.

Clinical Implant Dentistry and Related Research, 2003

ABSTRACTBackground: An increased number of publications report that one-stage surgery and immedia... more ABSTRACTBackground: An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients.An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients.Purpose: The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading.The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading.Materials and Methods: Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System® TiUnite™, Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry.Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System® TiUnite™, Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry.Results: Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 ± 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 ± 10.5% and a mean bone area value of 79.1 ± 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 ± 0.1% and 84.9 ± 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 ± 10.6% and 77.1 ± 6.8%, respectively.Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 ± 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 ± 10.5% and a mean bone area value of 79.1 ± 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 ± 0.1% and 84.9 ± 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 ± 10.6% and 77.1 ± 6.8%, respectively.Conclusions: The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.

Clinical Implant Dentistry and Related Research, 2008

Background: Previous studies have shown the formation of more bone contacts with a moderately rou... more Background: Previous studies have shown the formation of more bone contacts with a moderately rough and porous titanium surface, created by anodic oxidation, as compared with nonmodified turned titanium control surfaces. The mechanisms leading to a stronger bone response to oxidized titanium are not well understood.Purpose: The aim of the study was to describe the early events of bone integration of titanium implants with oxidized and turned surfaces.Materials and Methods: Nine adult New Zealand White rabbits and 18 implants were used in the study. One oxidized and one turned threaded titanium implants, which had been placed in the right tibial metaphysis, were analyzed in the present study. The implants were retrieved after 7, 14, and 28 days for light microscopic examination and histomorphometric measurements in ground sections.Results: Integration of oxidized implants was seen to occur as direct bone formation on the surface, while the integration of turned implants was a result of bone ingrowth from preexisting bone and bone marrow. For oxidized implants, an almost acellular, darkly stained layer was seen after 7 to 14 days, which later became populated with osteoblasts. The presence of osteoid seams indicated appositional bone growth from the substrate toward the surrounding tissues. The bone contact values were higher for oxidized implants, and the bone area values were higher for turned implants.Conclusions: The present study confirms the idea that implant surface modification alters the bone tissue response to titanium. The early bone formation following surgery occurs directly on the moderately rough oxidized surface, while turned titanium surfaces are integrated by the ingrowth of bone from the adjacent bone marrow and preexisting bone tissues.

International Journal of Oral and Maxillofacial Surgery, 2007

The aim of the study was to compare the integration and implant stability of turned and oxidized ... more The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p &amp;amp;amp;amp;lt; 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.

Anticancer Research, 2019

Background: Oral leukoplakia (OL) is a potentially malignant oral mucosal disorder. A casual asso... more Background: Oral leukoplakia (OL) is a potentially malignant oral mucosal disorder. A casual association between OL, oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) infection has been suggested, but no conclusive evidence has been presented. p16, a tumoursuppressor protein, is used as a surrogate marker for HPV infection. The aim of this study was to investigate how overexpression of p16 correlates with HPV infection in OL and in OSCC. Patients and Methods: Seventy-four patients with OL and 13 with OSCC with p16 overexpressed, were analyzed by immunohistochemistry visualizing p16 and a real-time polymerase chain reaction (

International Journal of Oral and Maxillofacial Surgery, 2007

The aim of the study was to compare the integration and implant stability of turned and oxidized ... more The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p &amp;amp;amp;amp;lt; 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.

Clinical Implant Dentistry and Related Research, Mar 1, 2003

Background: An increased number of publications report that one-stage surgery and immediate/early... more Background: An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients. Purpose: The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading. Materials and Methods: Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System® TiUnite™, Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry. Results: Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 ± 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 ± 10.5% and a mean bone area value of 79.1 ± 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 + 0.1% and 84.9 ± 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 ± 10.6% and 77.1 ± 6.8%, respectively. Conclusions: The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.

Clinical Oral Implants Research, 2004

Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery, Jan 13, 2017

The main objective of the present study was to assess the accuracy of two- and three-dimensional ... more The main objective of the present study was to assess the accuracy of two- and three-dimensional prediction techniques in orthognathic surgery. It was also a test of the very planning sequence. The scientific question was how well does the software support the surgeon in his way to find the perfect correction of the facial appearance while normalizing the occlusion? Thirty patients with a class III occlusion were included in this prospective study. Surgical planning with both techniques were undertaken for all patients. Surgery was performed according to the two-dimensional technique. The cephalometric measurements from two-dimensional and three dimensional predictions were compared with the postoperative results at the 12 months follow-up respectively. Together with an analysis of tracing error, placements of 2020 markers, 1860 measurements and 1280 comparisons was performed. The analysis showed an equally high accuracy for the studied techniques. The highest accuracy was found in ...

Clinical Implant Dentistry and Related Research, Sep 1, 2008

Background: Previous studies have shown the formation of more bone contacts with a moderately rou... more Background: Previous studies have shown the formation of more bone contacts with a moderately rough and porous titanium surface, created by anodic oxidation, as compared with nonmodified turned titanium control surfaces. The mechanisms leading to a stronger bone response to oxidized titanium are not well understood.

Aim Previous rabbit studies demonstrated higher affinity for bone formation at implant threads wi... more Aim Previous rabbit studies demonstrated higher affinity for bone formation at implant threads with furrows to threads without furrows. The present animal study was undertaken to study the bone tissue response and stability of oxidized titanium implants with 80, 110 and 160 μm wide furrows added on one thread flank. Materials and methods Ninety-six (96) threaded titanium implants, 3.75 mm in diameter and 7 mm long (TiUnite™, MKIII, Nobel Biocare AB, Gothenburg, Sweden), were manufactured with 70 μm deep and either 80 (S0), 110 (S1) or 160 (S2) μm wide furrows or no furrows (controls). The implants were installed in the distal femoral condyle and the tibial methaphysis of 12 rabbits. Six weeks later the implants were subjected to resonance frequency analysis (RFA) and removal torque (RTQ) tests, after ground sections were manufactured for light microscopy. Results A significantly increased (22%) stability of S1 implants in femoral sites compared with control implants was found. RFA s...

Background: Osseointegrated titanium implants are routinely used in clinical denstistry as anchor... more Background: Osseointegrated titanium implants are routinely used in clinical denstistry as anchorage units for dental prostheses. Although the overall clinical results are good, there are clinical situations when an optimized implant healing is desirable, for instance in order to shorten healing periods and to allow immediate loading. Aims: The present work was undertaken to study the influence of some microand macroscopical surface modifications on the integration and stability of titanium implants in bone. In addition, the aim was also to study the influence of a bone growth factor and autogenous bone grafts on implant healing in bone defects. Materials & Methods: The thesis is based on five experimental studies using a total of 12 mongrel dogs and 39 New Zealand White rabbits. In total, 327 screw-shaped implants were evaluated with histology and biomechanical tests. The implants had either a turned surface or had been treated with anodic oxidation to create a porous surface struc...

The International journal of oral & maxillofacial implants

Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of aut... more Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of autogeneic bone grafts or bovine bone mineral (BBM) combined with a space-making barrier enhances bone augmentation compared with a barrier alone. Sixteen rabbits were studied. In each rabbit, 2 titanium cylinders, each with 1 titanium lid, were placed subcutaneously in perforated slits made in the cortical bones, with their open ends facing the parietal bones. One cylinder was left empty and the other was filled with either autogeneic skull bone chips or BBM. Bone labels were injected after 4 and 11 weeks. After 12 weeks, the animals were sacrificed to obtain ground sections for histology and histomorphometry. Significantly more tissue was augmented in the 2 test groups than in the control group. Most of the autografts were resorbed, leaving only minute amounts in the upper third of the cylinders. Slender new bone trabeculae were distributed mainly from the contiguous bone plate that had n...

OSSEOINTEGRATION

Aim Previous studies have shown a preference for bone formation in macroscopic furrows as compare... more Aim Previous studies have shown a preference for bone formation in macroscopic furrows as compared to other parts of the implant surface. The aim of the study was to describe the early events of bone integration of furrowed oxidized titanium implants ...

eugenol.com

This PhD thesis represents number 32 in a series of investigations on implants, hard tissue and t... more This PhD thesis represents number 32 in a series of investigations on implants, hard tissue and the locomotor apparatus originating from the Department of Biomaterials/Handicap Research, Institute for Surgical Sciences at Göteborg University, Sweden.

International Journal of Oral and …, 2003

The International journal of oral & maxillofacial implants, 2003

PURPOSE Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether us... more PURPOSE Our primary aim was to use a rabbit guided bone augmentation model to evaluate whether use of autogeneic bone grafts or bovine bone mineral (BBM) combined with a space-making barrier enhances bone augmentation compared with a barrier alone. MATERIALS AND METHODS Sixteen rabbits were studied. In each rabbit, 2 titanium cylinders, each with 1 titanium lid, were placed subcutaneously in perforated slits made in the cortical bones, with their open ends facing the parietal bones. One cylinder was left empty and the other was filled with either autogeneic skull bone chips or BBM. Bone labels were injected after 4 and 11 weeks. After 12 weeks, the animals were sacrificed to obtain ground sections for histology and histomorphometry. RESULTS Significantly more tissue was augmented in the 2 test groups than in the control group. Most of the autografts were resorbed, leaving only minute amounts in the upper third of the cylinders. Slender new bone trabeculae were distributed mainly fro...

Clinical Implant Dentistry and Related Research, 2005

ABSTRACTBackground: The influence of thread design at the millimeter level and surface topography... more ABSTRACTBackground: The influence of thread design at the millimeter level and surface topography at the micrometer level on bone integration and the stability of dental implants have been studied extensively. However, less is known about the influence of implant structures in the range of 50 to 200 μm.The influence of thread design at the millimeter level and surface topography at the micrometer level on bone integration and the stability of dental implants have been studied extensively. However, less is known about the influence of implant structures in the range of 50 to 200 μm.Purpose: The present in vivo investigation was undertaken to study if bone formation and implant stability were influenced by 110 (S1) and 200 (S3) μm-wide and 70 μm-deep grooves positioned at a thread flank of oxidized titanium implants.The present in vivo investigation was undertaken to study if bone formation and implant stability were influenced by 110 (S1) and 200 (S3) μm-wide and 70 μm-deep grooves positioned at a thread flank of oxidized titanium implants.Materials and Methods: Eighteen rabbits and oxidized titanium implants (3.75 mm in diameter and 7 mm long) were used in the study. Nine rabbits received three control implants and three test implants with a 110 μm-wide groove added to one thread flank. The remaining nine rabbits received three control implants and three test implants with a 200 μm-wide groove. The animals were followed for 6 weeks. Removal torque (RTQ) tests were applied to two of the implants in each leg. The remaining implant per leg was retrieved for histology. The degree of bone fill within the grooves and corresponding bone formation at the opposing surfaces, the bone area within the threads, and the degree of bone-implant contact were calculated for each implant.Eighteen rabbits and oxidized titanium implants (3.75 mm in diameter and 7 mm long) were used in the study. Nine rabbits received three control implants and three test implants with a 110 μm-wide groove added to one thread flank. The remaining nine rabbits received three control implants and three test implants with a 200 μm-wide groove. The animals were followed for 6 weeks. Removal torque (RTQ) tests were applied to two of the implants in each leg. The remaining implant per leg was retrieved for histology. The degree of bone fill within the grooves and corresponding bone formation at the opposing surfaces, the bone area within the threads, and the degree of bone-implant contact were calculated for each implant.Results: The histologic analyses revealed an affinity for bone formation within the grooves. The RTQ tests showed that the peak RTQ was approximately 30% higher for the S1 implants compared with control implants without a groove. The difference was statistically significant (p < .05) for tibial and pooled implants. A similar but smaller and not statistically significant effect, approximately 8%, was measured for the S3 implants. The histomorphometric measurements confirmed the observed affinity of bone for the grooves. For S1 implants, 78.7 ± 15.8% of the grooves were filled with bone, whereas only 46.2 ± 27% of the corresponding flank surface showed the presence of bone (p < .05). The corresponding figures for S3 and control implants were 72.7 ± 25.1% and 48.5 ± 13.6%, respectively (p < .05). The degrees of bone-implant contact and bone area within the threads were similar for test and control implants.The histologic analyses revealed an affinity for bone formation within the grooves. The RTQ tests showed that the peak RTQ was approximately 30% higher for the S1 implants compared with control implants without a groove. The difference was statistically significant (p < .05) for tibial and pooled implants. A similar but smaller and not statistically significant effect, approximately 8%, was measured for the S3 implants. The histomorphometric measurements confirmed the observed affinity of bone for the grooves. For S1 implants, 78.7 ± 15.8% of the grooves were filled with bone, whereas only 46.2 ± 27% of the corresponding flank surface showed the presence of bone (p < .05). The corresponding figures for S3 and control implants were 72.7 ± 25.1% and 48.5 ± 13.6%, respectively (p < .05). The degrees of bone-implant contact and bone area within the threads were similar for test and control implants.Conclusion: It is concluded that 110 and 200 μm-wide and 70 μm-deep grooves at oxidized implant surfaces stimulated bone to preferentially form within and along the groove in the rabbit model. The 110 μm-wide groove was shown to increase the resistance to shear forces significantly. It is suggested that implants with such a groove may be one way to optimize implant stability in suboptimal clinical conditions.It is concluded that 110 and 200 μm-wide and 70 μm-deep grooves at oxidized implant surfaces stimulated bone to preferentially form within and along the groove in the rabbit model. The 110 μm-wide groove was shown to increase the resistance to shear forces significantly. It is suggested that implants with such a groove may be one way to optimize implant stability in suboptimal clinical conditions.

Clinical Implant Dentistry and Related Research, 2003

ABSTRACTBackground: An increased number of publications report that one-stage surgery and immedia... more ABSTRACTBackground: An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients.An increased number of publications report that one-stage surgery and immediate/early loading of dental implants may be a feasible approach for prosthetic reconstruction of the edentate patient. However, little is known about the histologic response to implants subjected to immediate/early loading in patients.Purpose: The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading.The aim of the present study was to histologically evaluate oxidized titanium implants subjected to loading immediately following surgery or after 2 months of healing and removed after 5 to 9 months loading.Materials and Methods: Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System® TiUnite™, Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry.Five patients participated in the study; each had consulted for implant treatment in the posterior mandible and subsequently volunteered to have extra implants inserted for the purpose of histologic research. Nine oxidized titanium implants (Brånemark System® TiUnite™, Nobel Biocare AB, Gothenburg, Sweden) were retrieved after 5 to 9 months in function. Two implants had been loaded the same day, whereas seven implants were loaded after 2 months of healing. Resonance frequency analysis was performed at retrieval on seven implants. Ground sections were prepared for histology and analyzed using light microscopic morphometry.Results: Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 ± 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 ± 10.5% and a mean bone area value of 79.1 ± 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 ± 0.1% and 84.9 ± 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 ± 10.6% and 77.1 ± 6.8%, respectively.Seven and 8.5 mm implants were placed, predominantly in quality 3 and 4 bone. Four implants were straight (Mk III), and five were tapered (Mk IV). All implants were clinically stable at retrieval and showed ISQ values of 65 to 79 with a mean of 71.4 ± 4.4. Eight of the implants were able to be used for histology. A gross histologic examination showed an undisturbed healing of soft and bone tissues with no apparent differences between response to immediately and early loaded implants. Lamellar bone surrounded the implants, and remodeling was evident and more marked near the implant surface. A condensation of bone toward the implant surface was seen; this resulted in a lamina dura-like structure in trabecular bone. Thin rims of newly formed bone were often seen following the contour of the implant surface. The morphometric measurements showed a mean bone-to-implant contact value of 84.2 ± 10.5% and a mean bone area value of 79.1 ± 6.8%. The two immediately loaded implants showed bone-to-implant contact and bone area values of 92.9 ± 0.1% and 84.9 ± 0.9%, respectively. The corresponding values for the six early loaded implants were 81.4 ± 10.6% and 77.1 ± 6.8%, respectively.Conclusions: The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.The present study demonstrated that oxidized implants subjected to immediate or early loading do integrate with soft and bone tissues in the posterior mandible.

Clinical Implant Dentistry and Related Research, 2008

Background: Previous studies have shown the formation of more bone contacts with a moderately rou... more Background: Previous studies have shown the formation of more bone contacts with a moderately rough and porous titanium surface, created by anodic oxidation, as compared with nonmodified turned titanium control surfaces. The mechanisms leading to a stronger bone response to oxidized titanium are not well understood.Purpose: The aim of the study was to describe the early events of bone integration of titanium implants with oxidized and turned surfaces.Materials and Methods: Nine adult New Zealand White rabbits and 18 implants were used in the study. One oxidized and one turned threaded titanium implants, which had been placed in the right tibial metaphysis, were analyzed in the present study. The implants were retrieved after 7, 14, and 28 days for light microscopic examination and histomorphometric measurements in ground sections.Results: Integration of oxidized implants was seen to occur as direct bone formation on the surface, while the integration of turned implants was a result of bone ingrowth from preexisting bone and bone marrow. For oxidized implants, an almost acellular, darkly stained layer was seen after 7 to 14 days, which later became populated with osteoblasts. The presence of osteoid seams indicated appositional bone growth from the substrate toward the surrounding tissues. The bone contact values were higher for oxidized implants, and the bone area values were higher for turned implants.Conclusions: The present study confirms the idea that implant surface modification alters the bone tissue response to titanium. The early bone formation following surgery occurs directly on the moderately rough oxidized surface, while turned titanium surfaces are integrated by the ingrowth of bone from the adjacent bone marrow and preexisting bone tissues.

International Journal of Oral and Maxillofacial Surgery, 2007

The aim of the study was to compare the integration and implant stability of turned and oxidized ... more The aim of the study was to compare the integration and implant stability of turned and oxidized titanium implants when placed in experimental bone defects with autogenous bone graft, BMP-2 or without adjunctive therapy. Four defects were prepared on each side of the mandible of 12 mongrel dogs five months after tooth extractions. Implants with turned and oxidized surfaces were placed in the defects. The circumferential gaps were filled with either autogenous bone grafts, a BMP-allogeneic dog mixture in a thermoplastic carrier, carrier alone or left without any treatment (control). There were no statistically significant differences between control and treated sites, neither for turned nor for oxidized implants with regard to histomorphometric measurements in ground sections and to implant stability as measured with resonance frequency analysis (RFA) after 4 and 12 weeks of healing. However, oxidized implants showed a significantly higher stability after 4 weeks and a tendency (p &amp;amp;amp;amp;lt; 0.1) of that after 12 weeks. Histomorphometry showed more bone contacts for oxidized than for turned implants. It is concluded that oxidized implants gain stability more rapidly and integrate with more bone contacts than implants with a turned surface when placed in bone defects.