Biomedical subjects

T Berglundh

Publications and source records attributed to T Berglundh.

At least 19 recordsLinked to original sources

PubMed2005

Inflammatory lesions in the gingiva following resective/non-resective periodontal therapy.

BACKGROUND: Findings from previous experiments have revealed that inflammatory cell infiltrates may remain in the gingiva following clinically successful non-surgical periodontal therapy. PURPOSE: To investigate the presence of inflammatory lesions in the gingiva following a periodontal treatment procedure that included either soft-tissue resection [gingivectomy (GV)] or non-resective open-flap debridement (OFD). MATERIAL AND METHODS: Fifteen patients with advanced generalized chronic periodontitis were recruited. Following oral hygiene instruction and supragingival debridement, one tooth site in each quadrant (non-molar, probing pocket depth>5 mm, bleeding on probing(+) and >50% bone loss) was selected and a soft-tissue biopsy was obtained and prepared for immunohistochemical analysis. Using a split-mouth design, two quadrants were randomly selected for periodontal therapy including GV, while the two remaining quadrants were exposed to non-resective OFD procedure. Six months after completion of surgical treatment, a new set of biopsies was obtained from GV and OFD sites. RESULTS: The inflammatory lesions residing in the gingival biopsies obtained prior to surgical therapy were 1.33-1.41 mm(2) large and contained similar proportions of CD19(+)- (B-cells, 15%), CD3(+)- (T-cells, 7%) and elastase(+)- (polymorphonuclear cells, 2%) cells in the two treatment groups. The corresponding lesions identified in the soft-tissue specimens obtained after 6 months of healing were twice as large at OFD as at GV sites (0.19 versus 0.08 mm(2), p=0.002). The densities of CD19(+)- and elastase(+)-cells in these lesions were significantly greater at OFD than at GV sites. CONCLUSION: The findings of the present study indicate that surgical therapy including soft-tissue resection results in regenerated gingival units that contain smaller lesions with lower densities of immunocompetent cells when compared with the lesions remaining in sites treated by non-resective means.

Adult↗

PubMed2005

Host response to microbial challenge following resective/non-resective periodontal therapy.

BACKGROUND: The host response to microbial challenge depends on the recruitment of homing leucocytes and may be related to the experience to infectious insults over years. PURPOSE: The aim of this study was to investigate the soft tissue reactions to de novo plaque formation at sites treated with either open flap debridement or with the use of resective means during periodontal therapy. MATERIAL AND METHODS: Fifteen patients, who had been treated for periodontal disease (severe generalized chronic periodontitis), participated in the study. Surgical therapy was performed using either gingivectomy (GV) or open flap debridement (OFD) procedures in a split mouth design. After 6 months of healing (day 0), two gingival biopsies were obtained, one from the GV- and one from the OFD-treated sites. The experimental gingivitis model was applied and plaque accumulation was allowed for 3 weeks. New biopsies were obtained from the remaining quadrants on day 21 of plaque formation. The biopsies were snap frozen and prepared for immunohistochemical analysis. RESULTS: Following 3 weeks of plaque accumulation, the size of the lesion in OFD sites was more than twice as large than that in GV sites (0.42 versus 0.19 mm2). In the GV units, the lesion was characterized by almost similar proportions of T cells (CD3+, 6.0%) and B cells (CD19+, 6.6%), while the ICT in OFD sites was dominated by B cells (13.8%). During the 3-week period of plaque formation the increase in cell densities of T and B cells was three times larger in OFD than in GV sites. The proportion of ELAM-1 (CD62+ cells) decreased in GV (-0.4%) and increased in OFD (0.9%) sites. CONCLUSIONS: The host response that occurred in the gingival sites treated with OFD was more pronounced than the reaction that under similar experimental conditions took place in the regenerated gingiva at sites treated by resective means.

Adult↗

PubMed2005

Bone reactions to longstanding functional load at implants: an experimental study in dogs.

OBJECTIVES: The aims of the present investigation were (i) to study marginal bone level alterations following implant installation, abutment connection and functional loading and (ii) to analyse bone tissue reactions to functional load. MATERIAL AND METHODS: Six beagle dogs, about 1-year old, were used. All mandibular pre-molars were extracted. Three months later four implants of the Astra Tech Implants Dental System were installed in one side of the mandible and four standard fixtures of the Brånemark System were placed in the contralateral side of the mandible. Abutment connection was performed 3 months later and a plaque control programme was initiated. Three months after abutment connection fixed partial dentures (FPDs) made in gold were cemented to the maxillary canines and pre-molars. FPDs were also connected to the three posterior implants in each side of the mandible, while the mesial implant in each side was used as an unloaded control. Radiographs were obtained from all implant sites following implant installation, abutment connection and FPD placement. Ten months after the FPD placement the radiographic examination was repeated. The animals were sacrificed and biopsies from all implant sites were obtained and prepared for histological analysis. RESULTS: The radiographic analysis revealed that largest amount of bone loss occurred following implant installation and abutment connection and that this loss was more pronounced at Brånemark than at Astra implants. The bone level alterations that were observed at implants exposed to 10 months of functional load in both implant systems were small and did not differ from control sites. The histological analysis revealed that implants exposed to functional load exhibited a higher degree of bone-to-implant contact than control implants in both implant systems. CONCLUSION: It is suggested that functional load at implants may enhance osseointegration and does not result in marginal bone loss.

Alveolar Bone Loss↗

PubMed2004

Spontaneous progression of experimentally induced periimplantitis.

BACKGROUND: Periimplantitis represents an inflammatory condition that is associated with the presence of a submarginal biofilm and with advanced breakdown of soft and mineralized tissues surrounding endosseous implants. Animal models have been used to describe mechanisms involved in the pathogenesis and treatment of the soft and hard tissue lesions of periimplantitis. OBJECTIVE: The aim of the present experiment was to study the presence and progression of inflammatory lesions in tissues surrounding implants exposed to "experimental periimplantitis". MATERIAL AND METHODS: Five Labrador dogs were used. In each dog, 2 or 3 implants were placed in both the left and right edentulous premolar regions of the mandible. Abutment connection was performed 4 months later and a plaque control regimen was initiated and maintained for 5 months. "Experimental periimplantitis" was subsequently induced by ligature placement and plaque accumulation was allowed to progress until about 40% of the height of the supporting bone had been lost. The ligatures were removed, but plaque formation was allowed to continue for an additional 12 months. Radiographs of all implant sites were obtained before and after active "experimental periimplantitis" as well as at the end of the experiment. Biopsies were harvested from the implant sites in 3 of the dogs. The tissue samples were prepared for light microscopy and the sections were used for histometric and morphometric examinations. RESULTS: One implant was lost during the first 2 months of "experimental periimplantitis" and two implants were lost during the 12 months that followed ligature removal. The radiographic examination indicated that varying amounts of additional bone loss occurred in the majority of the implant sites also following ligature removal. The mucosa of all implant sites harbored inflammatory lesions that extended apically of the pocket epithelium. The lesions were separated from the marginal bone by a zone of apparently normal connective tissue. CONCLUSION: A remission of the destructive inflammatory lesion in the periimplant tissues was seen in some sites following ligature removal, but in the majority of sites additional loss of supporting bone occurred.

Animals↗

PubMed2002

Bone reactions at implants subjected to experimental peri-implantitis and static load. A study in the dog.

AIM: The aim of the present experiment was to study peri-implant tissue reactions to lateral static load at implants subjected to experimental mucositis or peri-implantitis. MATERIAL AND METHODS: 5 beagle dogs were used. The mandibular premolars were extracted. After 12 weeks, 3 implants were installed in each quadrant of the mandible. In one side, the implants were designed with a SLA surface and in the contralateral side with a turned surface. A plaque control program was initiated. 12 weeks later, the central and posterior implants were connected with an appliance containing an expansion screw. Cotton ligatures were placed around the neck of the anterior and posterior implants in both sides, and the plaque control measures were terminated. Sixteen weeks later the ligatures were removed. After 8 weeks without ligatures, the expansion screws in both sides were activated. Once every 2 week during a 12-week interval, the screws were reactivated. Thus, the model included 3 different experimental sites of each surface group: group M+L (mucositis+load); group P (peri-implantitis); group P+L (peri-implantitis+load). Fluorochrome labels were injected and standardized radiographs obtained. The animals were sacrificed and block biopsies of all implant sites dissected and prepared for histological analysis. RESULTS: It was demonstrated that the lateral static load failed to induce peri-implant bone loss at implants with mucositis and failed to enhance the bone loss at implants with experimental peri-implantitis. The proportion of bone labels and the bone density in the interface zone were significantly higher in group P+L than in group P. CONCLUSION: It is suggested that a lateral static load with controlled forces may not be detrimental to implants exhibiting mucositis or peri-implantitis.

Alveolar Bone Loss↗

PubMed2002

The mucosal attachment to titanium implants with different surface characteristics: an experimental study in dogs.

BACKGROUND: Findings from in vitro studies have indicated that the orientation and proliferation of cells on titanium surfaces may be influenced by the topography of the surface on which they are grown. It may be argued, therefore, that differences may occur in the mucosal attachment to titanium implants with different surface roughness. AIM: The present experiment was performed to study the composition of the soft tissue barrier that formed to implants prepared with well-defined smooth or rough surfaces. MATERIAL AND METHODS: Five beagle dogs were used. Four implants made of c.p. titanium were placed in the right edentulous mandibular premolar region. After 3 months, two different types of abutments were connected: one experimental (OA) with a dual, thermal acid-etched surface ('Osseotite'), and one regular (RA) abutment with a 'turned' surface. At the end of a 6-month period during which proper plaque control had been maintained, biopsies including the implant and the surrounding soft and hard tissues were obtained, decalcified and processed for light and electron microscopy. A confocal He-Ne laser profilometer was used to study the surface topography of the abutments. RESULTS: The attachment between the peri-implant mucosa and titanium abutments with either a turned (RA; 'smooth') or acid-etched (OA; 'rough') surface was similar from both a quantitative and a qualitative aspect. The attachment comprised a barrier epithelium and a zone of connective tissue attachment of similar dimension at RA and OA. It was further observed that the 'inner' zone of the connective tissue attachment at both types of abutment was composed of about 30-33% fibroblasts and 63-66% collagen. CONCLUSION: It was demonstrated that the soft tissue attachment that formed to implants made of c.p. titanium was not influenced by the roughness of the titanium surface.

Acid Etching, Dental↗

PubMed2002

Soft tissue reactions to plaque formation at implant abutments with different surface topography. An experimental study in dogs.

BACKGROUND: The mucosal attachment that forms to titanium implants, uncontaminated by bacterial plaque comprises, independent of the surface characteristics of the abutment, one barrier epithelium and one zone of connective tissue attachment. It was suggested that abutments with a rough surface may accumulate more plaque than abutments with a smooth surface and that such an enhanced rate of plaque build-up may favor the development of inflammatory lesions in the periimplant mucosa. OBJECTIVES: The aim of the present experiment was to study some reactions of the periimplant mucosa to plaque accumulation on implant abutments designed with either a rough or a smooth external surface. MATERIAL AND METHODS: In five beagle dogs, four fixtures were placed and submerged in the premolar region. In a second stage procedure performed after 3 months, abutments with two different types of surface topography, one rough, acid-etched (OA) and one smooth, turned abutment (TA), were installed in a random order. After 6 months of undisturbed plaque formation, the animals were sacrificed and biopsies obtained. Tissue samples were prepared for light microscopy and exposed to histometric and morphometric measurements. RESULTS: Six months of plaque accumulation resulted in the establishment of an inflammatory lesion (pl-ICT) in the connective tissue of the periimplant mucosa, the location, size and composition of which did not differ between OA and TA sites. In addition, most OA and TA sites harbored a second inflammatory cell infiltrate in the tissue lateral to the abutment/fixture junction (ab-ICT). While pl-ICT was dominated by plasma cells and lymphocytes, ab-ICT contained a comparatively large number of polymorphonuclear leukocytes. CONCLUSION: The different surface characteristics of abutment made of c.p. titanium failed to influence plaque formation and the establishment of inflammatory cell lesions in the periimplant mucosa.

Acid Etching, Dental↗

PubMed2002

Expression of endothelial adhesion molecules in the alveolar ridge mucosa, gingiva and periimplant mucosa.

OBJECTIVES: The purpose of this study was to analyze the expression of adhesion molecules on endothelial cells in the alveolar ridge mucosa, the gingiva and the periimplant mucosa in humans. MATERIAL AND METHODS: Twelve partially edentulous subjects were included in the study. In each subject, one soft tissue biopsy was harvested from the edentulous alveolar ridge mucosa, one from a tooth site and one from an implant site. After 3 weeks of undisturbed plaque accumulation, an additional biopsy was obtained from one tooth and one implant site in each subject. The tissue samples were snap frozen and prepared for immunohistochemical analysis. RESULTS: In the alveolar ridge mucosa, smaller proportions of endothelial cells expressing ICAM-1, ELAM-1 and VCAM-1 were observed than in the gingiva. ELAM-1-positive cells occurred in lower numbers than in periimplant mucosa. After 21 days of plaque accumulation, ELAM-1 was increased in tooth sites, but decreased in periimplant mucosa. CONCLUSION: The results of the present study indicated that the proportions of activated endothelial cells and the extravasation of leukocytes is larger in gingiva and periimplant mucosa than in alveolar ridge mucosa. This might be due to the less permeable keratinized epithelial layer in the edentulous ridge mucosa, which offers proper protection against microbial pathogens. The greater expression of endothelial cell adhesion molecules during experimental gingivitis, compared to periimplant mucositis, may reflect its longer history of repeated antigenic assaults.

Aged↗

PubMed2001

Bone reactions adjacent to titanium implants subjected to static load. A study in the dog (I).

The aim of the study was to evaluate the effect of lateral static load induced by an expansion force on the bone/implant interface and adjacent peri-implant bone. In 3 beagle dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. Twelve weeks later 8 implants of the ITI Dental Implant System were placed in each dog. Crowns connected in pairs were screwed on the implants 12 weeks after implant installation. The connected crowns contained an orthodontic expansion screw yielding 4 loading units in each dog. Clinical registrations, standardized radiographs and fluorochrome labeling were carried out during the 24-week loading period. Biopsies were harvested and processed for ground sectioning. The sections were subjected to histological examination. No evident marginal bone loss was observed at either test or control sites. The bone density and the mineralized bone-to-implant contact were higher adjacent to the lateral loaded implants than at the unactivated control sites. It is suggested that the static load applied to implants in a lateral direction resulted in a structural adaptation of the peri-implant bone.

Adaptation, Physiological↗

PubMed2001

Bone reactions adjacent to titanium implants with different surface characteristics subjected to static load. A study in the dog (II).

The purpose of the present study was to compare bone reactions adjacent to titanium implants with either a titanium plasma-sprayed (TPS) or a machined surface subjected to lateral static loading induced by an expansion force. In 3 labrador dogs, the 2nd, 3rd and 4th mandibular premolars were extracted bilaterally. 12 weeks later, 2 implants with a TPS surface were placed in one side and 2 implants with a machined surface were placed in the contralateral side. Twelve weeks after implant installation, crowns, connected in pairs with orthodontic expansion screws, were fitted to the implants and a 0.6 mm wide expansion was initiated. Clinical registrations, standardized radiographs and fluorochrome labeling were carried out during a 24-week period of loading. Biopsies with the implants in situ were harvested and processed for ground sectioning. The sections were subjected to histologic and histometric examination. A higher marginal bone level was observed around implants with a TPS surface compared to machined implants. Furthermore, the values describing the amount of bone-to-implant contact at the bone/implant interface as well as the density of the peri-implant bone were lower at the machined than at the TPS implants.

Alveolar Process↗

PubMed2001

Bone reactions adjacent to titanium implants subjected to static load of different duration. A study in the dog (III).

The aim of the present experiment was to study the effect of a long-standing lateral static load on the peri-implant bone. Three beagle dogs were used. The mandibular premolars were extracted and 12 weeks later 3 titanium implants (ITI(R) Dental Implant System) were installed in each quadrant. Crowns were fitted to all implants 12 weeks after the installation procedure. The anterior and central crowns were fused and connected to the posterior crown by an expansion screw. In the right side of the mandible, the expansion screws were activated every 2 weeks during a 46-week period. During the last 10 weeks of this period, an expansion force similar to that of the right side was applied in the left. The animals were sacrificed and block biopsies of each implant site harvested and prepared for histological analysis. Sites subjected to 10 weeks or 46 weeks of lateral load had a similar (i) distribution of bone markers (ii) proportion of bone density and (iii) degree of bone-to-implant contact. The proportion of fluorochromes was higher at sites subjected to 10 weeks of loading than at sites subjected to 46 weeks of loading.

Alveolar Process↗

PubMed2001

Re-osseointegration after treatment of peri-implantitis at different implant surfaces. An experimental study in the dog.

Peri-implantitis is a condition that includes soft tissue inflammation and rapid loss of bone. Treatment of peri-implantitis includes both antimicrobial and bone augmenting methods. The question of whether true re-osseointegration may occur following treatment of peri-implantitis is controversial. The aim of this study was to investigate whether the character of the implant surface was of importance for the occurrence of re-osseointegration following treatment of peri-implantitis. Four beagle dogs were used. The mandibular premolars were extracted. After 12 months, 3 ITI(R) solid screw dental implants were placed in each side of the mandible. In the left side, implants with a turned surface (Turned sites) were used, while in the right side implants with a SLA surface (SLA sites) were placed. After 3 months of healing, peri-implantitis was induced by ligature placement and plaque accumulation. When about 50% of the initial bone support was lost, the ligatures were removed. Five weeks later, treatment was initiated. Each animal received tablets of Amoxicillin and Metronidazole for a period of 17 days. Three days after the start of the antibiotic regimen, one implant site (experimental site) in each quadrant was exposed to local therapy. Following flap elevation, the exposed titanium surface was cleaned with the use of cotton pellets soaked in saline. The implants were submerged. Six months later, biopsies were obtained. Treatment resulted in a 72% bone fill of the bone defects at Turned sites and 76% at SLA sites. The amount of re-osseointegration was 22% at Turned sites and 84% at SLA sites. A treatment regimen that included (i) systemic administration of antibiotics combined with (ii) granulation tissue removal and implant surface cleaning resulted in resolution of peri-implantitis and bone fill in adjacent bone defects. Further, while substantial "re-osseointegration" occurred to an implant with a rough surface (SLA), bone growth on a previously exposed smooth surface (Turned) was minimal.

Alveolar Bone Loss↗

PubMed2001

Some local and systemic immunological features of prepubertal periodontitis.

OBJECTIVES: The aim of the present investigation was to study local (gingival) and systemic host defense characteristics in a sample of children exhibiting local prepubertal periodontitis (LPP). MATERIAL AND METHODS: 2 groups of subjects were included in the present study. One group consisted of 11 children (9.5+/-2.0 years) with signs of periodontal disease (LPP group). A 2nd group comprised 21 adults (48.1+/-5.8 years) with advanced periodontal disease: adult periodontitis (AP) group. Gingival biopsies and a sample of peripheral blood were obtained in each individual of the AP group and in 7 out of the 11 subjects in the LPP group. The biopsies were prepared for morphometrical and immunohistochemical analysis and the blood samples prepared for immunohistochemical analysis. RESULTS: The cellular infiltrates in the biopsies of the LPP group contained a larger proportion of lymphocytes and, in particular B cells, than was the case in the AP group. The TCR Valpha/Vbeta gene expression in the lesions in the AP group was dominated by Vbeta 17 and in the LPP group by Valpha2. The content in peripheral blood of various lymphocyte sub-populations and TCR Valpha/Vbeta gene expression in the 2 groups was almost similar. CONCLUSION: It is suggested that (i) the systemic host response in children with prepubertal periodontitis has many features in common with that seen in adult patients but that (II) local defense mechanisms in the periodontitis lesion of LPP differ from those in adult periodontitis.

Adolescent↗

PubMed2001

Osseintegration following treatment of peri-implantitis and replacement of implant components. An experimental study in the dog.

AIM: The aim of the present experiment was to study if the quality of the titanium surface is a decisive factor for osseointegration and re-osseointegration. MATERIAL AND METHODS: 2 Labrador dogs were used. The mandibular 1st molars and all premolars were removed bilaterally. 3 months later, 1 standard fixture and 3, 2-part "test fixtures" were installed in each side of the mandible. The text fixtures consisted of 1 6-mm long apical and 1 4-mm long coronal part connected with an internal screw. After 4 months, abutment connection was performed. 5 months later, a period of experimental peri-implantitis was initiated during which about 50% of the supporting bone tissue was lost. The dogs were later subjected to a treatment that included (i) systemic administration of antibiotics and (ii) surgical debridement of all implant sites. The abutments and the coronal parts of the text fixtures were removed. All parts of the exposed portion of the standard fixtures, the connecting screw and the apical part of the test fixtures were meticulously cleaned by mechanical means. A pristine, coronal fixture part was via the connecting screw attached to the apical fixture part of each text fixture. All fixtures were submerged. 2 weeks later, a fluorochrome was injected intravenously. After 4 months, biopsies of the implant sites were dissected and prepared for ground sectioning and analysis. RESULTS: It was demonstrated that re-osseointegration failed to occur to implant surfaces (standard) exposed to bacterial contamination, but did consistently occur at sites where a pristine implant component was placed in the bone defect following surgical debridement. CONCLUSION: The above findings seem to imply that the quality of the titanium surface is of decisive importance for both osseointegration and re-osseointegration.

Alveolar Bone Loss↗

PubMed2001

Experimental peri-implant mucositis in man.

OBJECTIVES: The purpose of this study was to examine reactions of gingiva and peri-implant mucosa (PiM) to de novo plaque accumulation in humans. MATERIAL AND METHODS: Prior to the start of the study, which included 12 partially edentulous subjects, a 3-week plaque control program was performed. Ethical approval was granted by the local ethics committee. On day 0, 2 soft tissue biopsies were harvested, 1 from a tooth and 1 from an implant site in every subject. After 3 weeks of undisturbed plaque accumulation (day 21), 2 additional biopsies were obtained from the gingiva and PiM in each subject. The tissue samples, each 4x4 mm in size, were snap frozen and prepared for immunohistochemical analysis. RESULTS: The size of the infiltrate (ICT) in the day 0 biopsies, was about 0.03 mm2 in both the gingiva and PiM. At the end of the plaque accumulation period, the size of the lesion had significantly increased in both groups and occupied an area of 0.26 mm2 in the gingiva and 0.14 mm2 in PiM. In the biopsies presenting day 0, the proportions of the various cell populations examined were similar in the gingiva and in PiM. The tissue fractions of almost all types of cells increased during the 3 weeks, but the mean change for each cell type was greater in the gingiva than in PiM. The CD3/CD19 ratio decreased in the gingiva between day 0 and 21, but increased in PiM. CONCLUSION: The results of the present study indicated that plaque accumulation induced an inflammatory response characterized by increased proportions of T- and B-cells in the ICT of both the gingiva and the PiM. Although not statistically significant, the host response in the gingiva tended to be more pronounced than in the peri-implant mucosa.

Aged↗

PubMed2001

Orthodontic movement in bone defects augmented with Bio-Oss. An experimental study in dogs.

OBJECTIVE: To study if it was possible to move, by orthodontic means, a tooth into an area of the jaw that had been augmented with Bio-Oss. MATERIAL AND METHODS: 5 beagle dogs were used. The 1st, 2nd, and 4th mandibular premolars on each side were removed. The defect at the left 4th premolar site was filled with a biomaterial (Bio-Oss) while the corresponding defect in the right side was left for spontaneous healing. 3 months later, an orthodontic device was inserted in each side of the mandible. The device was designed to allow distal, bodily movement of the 3rd premolars. When the experimental teeth had been moved into the extraction sites of the 4th premolars, the animals were sacrificed and biopsies of the premolar-molar regions of the mandible sampled. The tissues were prepared for histological analysis using standard procedures. In the sections, 3 zones were identified: zone A=the bone tissue within the distal portion of the previous extraction site (4th premolar), zone B=the pressure side of the 3rd premolar, zone C=the tension side of the 3rd premolar. The area occupied by mineralized bone, Bio-Oss particles and bone marrow was determined by a point counting procedure. The width of the periodontal ligament as well as the percentage of the root surface (in zone B) that exhibited resorption was determined. RESULTS: The findings demonstrated that it was possible to move a tooth into an area of an alveolar ridge that 3 months previously had been augmented with a biomaterial. It was also demonstrated that 12 months after grafting, Bio-Oss particles remained as inactive filler material in the not utilized part of zone A. The biomaterial was not present in zone C but present in small amounts in zone B. CONCLUSION: During the orthodontic tooth movement the graft material (Bio-Oss) was degraded and eliminated from the part of the alveolar ridge that was utilized for the experiment. In the non-utilized part of the ridge the biomaterial, however, remained as a seemingly inactive filler material.

Alveolar Process↗

PubMed2001

Alveolar ridge augmentation with Bio-Oss: a histologic study in humans.

The aim of the present study was to investigate the healing of alveolar ridge defects augmented with cancellous bovine bone mineral. In six partially edentulous patients, bone augmentation was necessary prior to implant placement because of severe alveolar ridge resorption. The defect sites, all located in the maxilla, were filled with Bio-Oss and covered with the resorbable collagen membrane Bio-Gide. Biopsies were obtained from the defect sites 6 to 7 months following grafting and were processed for ground sectioning. The histologic analysis revealed that the Bio-Oss particles occupied 31% of the total biopsy area. An intimate contact between woven bone and Bio-Oss was detected along 37% of the particle surfaces. A mixed type of bone was found; it contained woven bone and parallel-fibered bone, which demonstrates features of remodeling activity. Signs of resorption of the grafting material were observed in the histologic sections, which indicates that the material takes part in the remodeling process. It is suggested that Bio-Oss may be a very suitable material for staged localized ridge augmentation in humans.

Adult↗

PubMed2000

Bone healing around implants placed in a jaw defect augmented with Bio-Oss. An experimental study in dogs.

The present experiment was carried out to study some tissue reactions around implants that were placed in an edentulous ridge which had been augmented with deproteinized natural bovine cancellous bone mineral. In 4 male beagle dogs, the premolars in the right side of the mandible were extracted and a large buccal ridge defect was created by mechanical means. The bone plate at the lingual aspect of the defect was left intact. 5 months later, the distal 2/3 of the defect area was augmented with Bio-Oss (Geistlich Sons Ltd, Wolhusen, Switzerland) mixed with a fibrin sealer (Tisseel, Immuno AG, Vienna, Austria). After 3 months of healing, 3 fixtures (Astra Tech AB, Mölndal, Sweden; TiO-blast; 8x3.5 mm) were installed in the mandible; 2 were placed in the augmented portion and I was placed in the non-augmented portion of the defect. After a healing period of 3 months, abutment connection was performed and a plaque control period initiated. 4 months later, the dogs were sacrificed and each implant region was dissected. The tissue samples were dehydrated, embedded in plastic, sectioned in the bucco-lingual plane and examined in the light microscope. It was observed that osseointegration failed to occur to implant surfaces within an alveolar ridge portion previously augmented with Bio-Oss. In the augmented portion of the crest, the graft particles were separated from the host tissue as well as from the implant by a well-defined connective tissue capsule. Although the lingual aspect of all fixtures (test and control) was in contact with hard tissue at the time of installation, after 4 months of function, a deep vertical bone defect frequently had formed at the lingual surface of the implants. It was concluded that in this model (i) Bio-Oss failed to integrate with the host bone tissue and (ii) no osseo-integration occurred to the implants within the augmented portion of the crest.

Alveolar Ridge Augmentation↗