225 research outputs found
Bone tissue reaction around implants placed in a compromised jaw
No full textThe present experiment was carried out to examine bone tissue alterations that occurred around implants at which the marginal level of bone support at fixture installation was different at buccal and lingual surfaces. 8 beagle dogs were randomly divided into one test group and one control group. The mandibular premolars in the left side of the mandible (P1, P2, P3, P4) were extracted. In the 4 dogs of the test group, the buccal bone plate in the mandibular premolar region was removed to establish a bone defect that was about 25 mm long, about 5-6 mm high, and about 4 mm wide. In the 4 dogs of the control group, no bone resection was performed. 8 months after tooth extraction, 3 fixtures (Astra Tech AB, Mölndal, Sweden:TiO-blast: 8x3.5 mm) were installed in each dog. In the 4 dogs of the test group, the implants were positioned in the defect sites in such a way that (i) mechanical stability was achieved and (ii) their lingual surfaces were entirely invested in bone. At the buccal and approximal surfaces of the fixtures, however, the unthreaded portion (2 mm) and the 3 marginal threads remained exposed. In the control group, all implants were following installation entirely surrounded by bone tissue. After a healing period of 3 months, abutment connection was performed and a plaque control program initiated. 4 months later, the dogs were sacrificed. The mandibles were removed and placed in a fixative. Each implant region was dissected, the tissue samples were dehydrated, embedded, sectioned in a bucco-lingual plane and used for light microscopic examination. The findings demonstrated that osseointegration occurred at implants, placed in a chronic defect with large discrepancies between the buccal and lingual bone. During the process of healing and function, however, marked modeling and remodeling of the bone tissue took place. Thus, at the buccal surface, some bone regrowth and osseointegration occurred while at the lingual wall, there was a substantial resorption of the marginal bone and an enhanced number of bone multicellular units. Concomitant with the bone tissue alterations described, there was some recession of the peri-implant mucosa
Bone healing around implants placed in a jaw defect augmented with Bio-Oss. An experimental study in dogs
No full textThe 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
“Peri-Implantitis”: A Complication of a Foreign Body or a Man-Made “Disease”. Facts and Fiction
No full textBackground: The discrepancy between some scientific views and the daily clinical experience with dental implants has
made the topic of “periimplantitis” highly controversial, especially the discussion whether “periimplantitis” should even
be considered a “disease” or whether marginal bone loss instead would represent a complication of having a foreign
body placed in the oral cavity.
Purpose: The aim of the present paper was to present the outcomes from a consensus meeting on “peri-implantitis” in
Rome, Italy (January 8–10, 2016).
Materials and Methods: Seventeen clinical scientists were invited to, based on prepared reviews of the literature, discuss
topics related to “periimplantitis.”
Results and conclusions: Oral implants may lose bone or even display clinical failure. However, progressive bone loss
threatening implant survival is rare and limited to a percent or two of all implants followed up over 10 years or more,
provided that controlled implant systems are being used by properly trained clinicians. There is very little evidence
pointing to implants suffering from a defined disease entity entitled “peri-implantitis.” Marginal bone loss around
implants is in the great majority of cases associated with immune-osteolytic reactions. Complicating factors include
patient genetic disorders, patient smoking, cement or impression material remnants in the peri-implant sulcus, bacterial
contamination of the implant components and technical issues such as loose screws, mobile components or fractured
materials. These reactions combine to result in cellular responses with the end result being a shift in the delicate balance
between the osteoblast and the osteoclast resulting in bone resorption. However, the great majority of controlled implants
display a foreign body equilibrium resulting in very high survival rates of the implants over long term of follow-u
“Comparing the tioblast and osseospeed surfaces. histomorphometric and histological analysis in humans”
No full textBook Review
No full text Ageing, Osteoporosis, and Dental Implants. G. Zarb, U. Lekholm, T. Albrektsson and H. Tenenbaum, eds. Quintessence Publishing Co. Ltd, New Malden, 2002 (260pp., £55.00 s/b). ISBN 0-86715-407-1. </jats:p
Evaluation of the tissue response of organic, metallic, ceramic and osteoceramic tooth roots
No full textFour classes of materials, inert organic, inert metal, inert ceramic and biologically-active osteoceramic were implanted in the edentulous mandibles of dogs. Tissue response was evaluated at 3, 6, 9, 12 and 18 months by light microscopy; microradiography; clinical evaluation for mobility, rotation, bleeding and radiography; and epi fluorescent analysis of bone growth labels. The pyrolytic carbon implants were not osseous integrated. The bone contact area of the sapphire and titanium alloy implants increased to 60 and 80%, respectively, at 12 months; but decreased to 20% and 60% at 18 months. The area for the osteoceramic was 80% at three months and remained at that level. These results indicate superior tissue response for the osteoceramic material, a ceramic composite of Ca-3(PO4)(2) and MgAl2O4.PT: S; CR: ALBREKTSSON T, 1988, J PERIODONTOL, V59, P287 BAGAMBISA FB, 1990, INT J ORAL MAXILLOF, V5, P217 BLOCK MS, 1990, J ORAL MAXIL SURG, V48, P174 BRUNSKI J, 1988, CDAJ, P66 CARLSSON L, 1994, J ORTHOPAED RES, V12, P274 COOK SD, 1987, INT J ORAL MAXILLOF, V7, P485 DEGROOT K, 1980, BIOMATERIALS, V1, P47 DENISSEN HW, 1986, CURRENT PRACTICE SER, V29, P372 GOTTLANDER M, 1992, CLIN ORAL IMPLAN RES, V3, P71 GOTTLANDER M, 1992, INT J ORAL MAXILLOF, V7, P485 JANIKOWSKI T, 1969, P IOWA ACAD SCI, V76, P113 JARCHO M, 1977, J BIOENG, V1, P70 JOHNSON BW, 1992, J CALIF DENT ASSOC, V20, P33 MCGEE TD, 1974, 3787900, US MCGEE TD, 1974, J BIOMED MAT RES S, V5, P137 MCGEE TD, 1995, ENCY HDB BIOMATERIAL, V1, P69 MCGEE TD, 1995, ENCY HDB BIOMATERIAL, V2, P1413 MCKINNEY RJ, 1982, J ORAL IMPLANT, V10, P619 MEFFERT RM, 1985, IOWA SOC PERIOD 0301 MEFFERT RM, 1987, INT J PERIODONT REST, V4, P9 SCHNITMAN PA, 1993, J AM DENT ASSOC, V124, P39 STILLMAN N, 1993, J AM DENT ASSOC, V124, P51 TWEDEN KS, 1987, THESIS IOWA STATE U VERHEYEN CCPM, 1993, J BIOMED MATER RES, V27, P433 WEINLANDER M, 1992, INT J ORAL MAXILLOF, V7, P491; NR: 25; TC: 3; J9: MATER SCI FORUM; PG: 20; GA: BM15ESource type: Electronic(1
Investigation of the Osseointegration of Dental Implants and Different Biomaterials Used in Guided Tissue Regeneration
No full textChapter 3 Hard Tissue Response
No full textThe initial tissue response when a biomaterial is implanted in the body is dependent on release of specific growth factors. It has been indicated by Frost [1] that the inevitable bone injury resulting from surgery and the presence of an implant will release various types of growth factors that will sensitize cells and promote cellular mitosis. This is a general healing response that will result in growth of all sorts of local connective tissues, bone as well as various types of soft tissue. © Springer Science+Business Media New York 2016
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