Osseointegration Of Endosseous Implants Research Articles

Consideraţii privind osteointegrarea implanturilor dentare endoosoase

Implant osseointegration has not been accepted over time, considering that in fact the implant integration is performed only in the soft tissue of the host. For this reason, the implant has never been sufficiently integrated into the host tissue immediately after insertion. Experiments performed in Branemark laboratories in the early 1960s, with a new type of implant, which required a direct anchorage to bone tissue for clinical function, this anchorage was called osseointegration. It has been shown that it is possible to achieve direct osseointegration if the Branemark method is considered, which was published a few years later in the first clinical report. The authors of this article come up with new contributions that validate the implant osseointegration process. Inside this article we present our methodology for evaluating the osseointegration of endosseous implants: ESEM (environmental scanning electron microscope) studies of the implant-bone tissue interface.

Macrophage Control of Incipient Bone Formation in Diabetic Mice.

Both soft and hard tissue wound healing are impaired in diabetes. Diabetes negatively impacts fracture healing, bone regeneration and osseointegration of endosseous implants. The complex physiological changes associated with diabetes often manifest in immunological responses to wounding and repair where macrophages play a prominent role in determining outcomes. We hypothesized that macrophages in diabetes contribute toward impaired osseous wound healing. To test this hypothesis, we compared osseous wound healing in the mouse calvaria defect model using macrophages from C57BL/6J and db/db mice to direct osseous repair in both mouse strains. Initial analyses revealed that db/db mice macrophages showed an inflamed phenotype in its resting state. Incipient bone regeneration evaluated by μCT indicated that bone regeneration was relatively impaired in the db/db mouse calvaria and in the calvaria of C57BL/6J mice supplemented with db/db macrophages. Furthermore, osteogenic differentiation of mouse mesenchymal stem cells was negatively impacted by conditioned medium from db/db mice compared to C57BL/6J mice. Moreover, miR-Seq analysis revealed an altered miRNA composition in db/db macrophages with up regulated pro-inflammatory miRNAs and down regulated anti-inflammatory miRNAs. Overall, this study represents a direct step toward understanding macrophage-mediated regulation of osseous bone regeneration and its impairment in type 2 diabetes mellitus.

REVIEW AND SUCCESS RATE OF ENDOSSEOUS IMPLANTS IN MAXILLOFACIAL PROSTHESIS

Aim: Endosseous osseointegrated implants have enormously increased the potential for reconstruction of the patients with varied soft and hard tissue maxillofacial defects. This review focuses on the survival rate of endosseous implants in maxillofacial prosthesis.
 Background: In recent years, the endosseous implants for prosthetic rehabilitation of maxillofacial defects with acquired and congenital conditions have become more common practice with higher percentage of long-term success. Endosseous implants have been used for retention in the maxillofacial defects can offer excellent support and retention thereby eliminating the usage of adhesives.
 Review results: Maximum number of systematic reviews has been compiled by different authors on the success rate of endosseous implants. However, endosseous osseointegrated implants can remain in service for a long term, and many techniques are reliable and predictable.
 Conclusion: This article highlights the long-term outcomes of endosseous implants used to retain the various types of maxillofacial prosthesis.
 Keywords: Craniofacial defects, endosseous implants, maxillofacial prosthesis, osseointegration, maxillofacial defects.

Tissue Engineering Therapy for Atrophic Maxilla Using Minimally Manipulated CD90 and CD105 Bone Marrow Stem Cells: A Case Report

Bone deficiencies in the jaws of edentulous patients limit the possibility of successful placement and osseointegration of endosseous implants. Bone resorption is defined as a vertical and horizontal loss of quality and quantity in the residual bone ridges; lack of bone structure requires bone grafting procedures to enable implant placement and to improve the function, predictability, and longevity of implants. The objective of this case study was to demonstrate the feasibility of a novel cell therapy treatment for localized jaw bone defects with tissue repair cells composed of a mixture of bone marrow-derived cells, including CD90+ mesenchymal stem cells and CD105+ monocytes/macrophages, and xenograft blocks, in what would be a safe and efficacious approach to the regeneration of localized craniofacial bone defects. The use of stem cells represents an alternative that could offer improved results, better quality histologically, and greater quantity in millimeters of tissue in bone regeneration.

The effects of zoledronic acid and dexamethasone on osseointegration of endosseous implants: histological and histomorphometrical evaluation in rats

Bisphosphonates are a widely used class of drugs that prevent bone loss. Several side effects related to bisphosphonate therapy have been reported, including osteonecrosis of the jaws associated with invasive dental procedures and implants placement. To evaluate the influence of intravenous nitrogen-containing BPs in combination with or without dexamethasone on osseointegration of titanium implants placed in an animal model. Twenty-seven male Wistar rats were divided into three groups: group 1 was treated solely with zoledronic acid, group 2 was treated with zoledronic acid and dexamethasone, and group 3 did only receive saline solution injections. Two endosseous implants were placed in each tibia, and three animals from each group were sacrificed at postoperative times of seven, 14, and 28 days. Non-decalcified sections were observed with light microscopy for histological and histomorphometrical analyses. Histomorphometrical analysis using the animals and the implants as unit of measurement revealed no statistically significant difference regarding bone-implant contact and bone density among the three groups. Histological observation revealed that zoledronic acid-treated animals in combination with or without dexamethasone showed expressive less bone remodeling activity at 14 and 28 days after implants placement, compared with control specimens. The studied bisphosphonate regimens did not interfere with the osseointegration of the implants, cortical, or medular bone deposition, but a possible lack of bone remodeling of the original cortical bone may affect long-term osseointegration.

İmplant destekli sabit ve hareketli protezlerde implant kırığı komplikasyonu: 2 olgu sunumu

Objectives: The aim of this case report is topresent the treatment methods of implant fracturesobserved in 2 edentulous patients who rehabilitatedwith fixed and removable dentures.Materials and Methods: The widespread useof endosseous osseointegrated implants to replacemissing natural teeth results with the complicationsand failures, despite the high initial success ratereported in the literature. Complications on dentalimplants may be observed in short or long termperiods. Implant fracture is one of the mechanicalcomplications that can be encountered in the longterm period and may be related to implant type,width, location, bone support, occlusal forces,restoration design or time. Fracture of the implantsis a rare phenomenon with severe clinical results. Itis important to know and apply the measuresrequired to prevent implant fracture, and to seek thebest individualized solution for each case - thoughcomplete implant removal is usually the treatmentof choice.

The effects of pulsed electromagnetic field on the functions of osteoblasts on implant surfaces with different topographies

The use of pulsed electromagnetic fields (PEMFs) is a promising approach to promote osteogenesis. However, few studies have reported the effects of this technique on the osseointegration of endosseous implants, especially with regard to different implant topographies. We focused on how the initial interaction between cells and the titanium surface is enhanced by a PEMF and the possible regulatory mechanisms in this study. Rat osteoblasts were cultured on three types of titanium surfaces (Flat, Micro and Nano) under PEMF stimulation or control conditions. Protein adsorption was significantly increased by the PEMF. The number of osteoblasts attached to the surfaces in the PEMF group was substantially greater than that in the control group after 1.5h incubation. PEMF stimulation oriented the osteoblasts perpendicular to the electromagnetic field lines and increased the number of microfilaments and pseudopodia formed by the osteoblasts. The cell proliferation on the implant surfaces was significantly promoted by the PEMF. Significantly increased extracellular matrix mineralization nodules were observed under PEMF stimulation. The expression of osteogenesis-related genes, including BMP-2, OCN, Col-1,ALP, Runx2 and OSX, were up-regulated on all the surfaces by PEMF stimulation. Our findings suggest that PEMFs enhance the osteoblast compatibility on titanium surfaces but to different extents with regard to implant surface topographies. The use of PEMFs might be a potential adjuvant treatment for improving the osseointegration process.

Comparison of peri‐implant crevicular fluid levels of adrenomedullin and human beta defensins 1 and 2 from mandibular implants with different implant stability quotient levels in nonsmoker patients

To achieve satisfactory osseointegration, primary stability and healthy peri-implant tissue must be available. In this study, our objective was to compare the adrenomedullin, human beta-defensin (hBD)-1 and hBD-2 levels in implants with different implant stability quotient (ISQ) values and with different peri-implant tissue health values in the peri-implant crevicular fluid. Thirty patients with 60 endosseous osseointegrated implants were included in this study. Following the completion of the osseointegration process, these implants were divided into two main groups: a group of 15 implants with peri-implantitis (peri-implantitis: 40 ≤ ISQ ≤ 80 peri-implantitis, n = 15) and a group of 45 implants with healthy peri-implant tissue. The healthy peri-implant tissue group was further divided into three subgroups according to their ISQ values (Healthy-60: 60 ≤ ISQ ≤ 70, healthy peri-implant, n = 15; Healthy-80: 71 ≤ ISQ ≤ 80, healthy peri-implant, n = 15; and Healthy-100: 81 ≤ ISQ ≤ 100, healthy peri-implant, n = 15). The levels of adrenomedullin, hBD-1 and hBD-2 in the peri-implant crevicular fluid were assessed using ELISAs. When the peri-implant clinical measurements were compared within groups, they were found to be highest in the peri-implantitis group and lowest in the Healthy-100 group. The adrenomedullin, hBD-1 and hBD-2 levels in the peri-implant crevicular fluid of the peri-implantitis group were found to be significantly higher than those in the Healthy-60, Healthy-80 and Healthy-100 groups. When only the healthy peri-implant tissue groups were evaluated, the adrenomedullin, hBD-1 and hBD-2 levels in the peri-implant crevicular fluid of the Healthy-60 group were found to be significantly higher than those in the Healthy-80 and Healthy-100 groups. The lowest adrenomedullin, hBD-1 and hBD-2 levels were observed in the Healthy-100 group. In cases of peri-implantitis, higher adrenomedullin, hBD-1 and hBD-2 levels were observed. These results indicate the presence of a tissue response to prevent the creation of a pathological environment in the peri-implant tissue. In groups with healthy peri-implant tissues, the ISQ value decreases as the adrenomedullin, hBD-1 and hBD-2 levels increase. This condition is thought to be caused by increased dental plaque accumulation and bone resorption in addition to increased lateral implant movements and colonization of microorganisms in the microcavities between the implant elements.

Osseointegrated Supported Prosthesis and Interdisciplinary Approach for Prosthodontic Rehabilitation of a Young Patient with Ectodermal Dysplasia

Anhidrotic ectodermal dysplasia is a triad of hypodontia or anodontia, hypotrichosis, and hypohydrosis, associated with other problems that result from the defective development of structures of ectodermal origin (Freire-Maia, Pinheiro (1988)). Early and extensive dental treatment is needed keeping in mind the effect on the craniofacial growth. Due to rapid growth of the jaws, the patients are rehabilitated using removable prostheses (Tarjan et al. (2005)). Hence for a young patient in this case report, the placement of endosseous osseointegrated implants was delayed till adulthood. Finally a definitive fixed tooth-supported and osseointegrated implant supported fixed partial denture therapy was used to rehabilitate the patient satisfactorily after she had completed her growth (Sweeney et al. (2005)). A review of the current literature relevant to several aspects of syndromic hypodontia, patient selection, and implant planning is discussed.

Effects of a calcium phosphate coating on the osseointegration of endosseous implants in a rabbit model

The aim of the present study was to evaluate a Ca-P coated implant surface in a rabbit model. The Ca-P surface (test) was compared to the titanium porous oxide surface (control) in terms of bone-to-implant contact (BIC) and removal torque value. Two hundred and sixteen dental implants were inserted in the tibia and in the femur of 36 rabbits. One hundred and eight were represented by Ca-P oxidized surface implant and other 108 were titanium porous oxide surface modified implants. Each rabbit received six implants. Animals were sacrificed after 2, 4 and 9 weeks of healing. Each group included 12 rabbits. The femoral implant and the proximal implant of the tibia of each animal were subjected to the histologic analysis and the distal implants of the tibia underwent removal torque test (RTQ). Histological analysis in terms of BIC and RTQ did not revealed any significant difference between the Ca-P oxidized surface and the oxidized surface at 2 and 4 weeks. At 9 weeks, the oxidized surface demonstrated better results in terms of RTQ in the tibia. In conclusion, findings from the present study suggested that the Ca-P coating had no beneficial effect in improving bonding strength at the bone-implant interface either at 2, 4 and 9 weeks.

Resolution of a titanium implant fracture after a recurrent trauma

Post-traumatic complications occasionally lead to tooth loss as well as the need for future implants. However, rehabilitation with endosseous osseointegrated implants does not protect the patient from the risk of suffering a new trauma. Implant fracture and the damage of the hexagon are post-traumatic complications that guide the clinician to preparing a more intricate treatment plan. The authors present a clinical case of a recurrent trauma of maxillary implant fracture. The treatment plan was to remove the implants followed by autogenous bone grafting to correct the defect. Two titanium implants were replaced, followed by connective tissue graft after allowing complete the healing process of the bone graft to occur. In the postoperative period of 6 months, satisfactory results have been shown as regards soft and hard tissues wound healing.

“13-23-30” Anatomic Approach for Maxillary Full-Arch Implant Reconstruction: A Case Report and Surgical-Prosthetic Considerations

For the past 30 years, implant treatment has been advocated for partially and fully edentulous patients to improve function, esthetics, phonetics, and comfort. Patients can now benefit from removable and fixed implant-retained and implant-supported prostheses using the bone-anchoring techniques of endosseous osseointegrated implants. Much research has been done on complete maxillary implant reconstruction because of the large number of patients with edentulous maxillas and an enormous armamentarium of surgical-prosthetic implant techniques used in these cases. In the present article, one more technique is recommended, an anatomically based surgical-prosthetic approach--"13-23-30"--that should help a clinician with the initial selection of implant sites when contemplating an implant treatment of edentulous maxilla with a fixed 6-implant-supported hybrid prosthesis. This technique is based on the anatomy and function of mastication of natural dentition. The rationale behind this anatomic concept of treatment is discussed, and a case report is presented.

Management of Dental Implant Fractures. A Case History

The widespread use of endosseous osseointegrated implants to replace missing natural teeth increases the chances of implant complications and failures, despite the high initial success rate reported in the literature. Implant fracture is one possible complication that results in ultimate failure of the dental implant. Such a complication poses a management crisis even for the most experienced clinician. This article reports on a case of implant fracture, its possible causes, and how the case was managed.

Elevation of the Maxillary Sinus Floor with Hydraulic Pressure

This study describes a new method using hydraulic pressure to elevate the antral floor for bone grafting between the sinus floor and the schneiderian membrane before placement of endosseous osseointegrated implants. The method was first modeled experimentally in hen eggs, acting as a surrogate sinus, and then in human cadaver preparations. Several clinical case reports are also presented. This technique successfully combines the advantages of the Caldwell-Luc window a pproach, which permits the placement of high bone graft volume, and the simplicity of the osteotome technique by way of the alveolar ridge crest.

Effects of noninvasive electrical stimulation on osseointegration of endosseous implants: A histomorphometric evaluation in the rabbit tibia

Effects of noninvasive electrical stimulation on osseointegration of endosseous implants: A histomorphometric evaluation in the rabbit tibia

Fracture of the body of an implant and its management — a case history

The increasing use of endosseous osseointegrated implants to replace natural teeth will inevitably lead to an increase in patients presenting in general dental practice with failing implants. A fractured implant body is not a common cause of failure, however it is a common cause of late failure. There is evidence that careful treatment planning can reduce the incidence of fracture. This paper describes a case demonstrating the management of implant fracture and discussing a possible mechanism for this failure. Some of the previously described factors that have been thought to contribute towards fracture are also discussed.

Implantology

Endosseous osseointegrated implants have become an integral part of the treatment scheme for the prosthetic reconstruction and rehabilitation of masticatory function following scientific studies of the reactions between implant and soft and hard tissues. Furthermore, implants offer good chances for prosthetic rehabilitation in the insufficient bone site, if the extremely atrophic jaw is to be reconstructed by grafting procedures with avascular and vascular grafts, by guided bone regeneration, by distraction osteogenesis, by bone substitutes and in the future by osteoinductive proteins in order to prepare the conditions for implant insertion. Those reconstruction procedures combined with implants become often necessary, if complicated hard and soft tissue defects of the skull have to be reconstructed to create the prerequisites for the stabilisation of epitheses or to insert implant-supported devices.

Treatment of the edentulous mandible with a vestibuloplasty combined with intramobil Zylinder implants: a 5-year follow-up

The long-term success of endosseous implants is related to healthy peri-implant tissues. Attached keratinized mucosa does not seem important for the prevention of soft tissue complications. Prevention of muscle attachment near the implants, however, seems more decisive for maintaining a favourable peri-implant environment. We treated 150 patients from 1990-91 with two Intramobil Zylinder implants and modified vestibuloplasty, 65 of whom were randomly selected for evaluation at 1 year; 48 of the 65 were also seen at 5 years. The vestibuloplasty was done by the technique of Pichler and Trauner, to prevent muscle pull and to create a thin layer of mucosa around the implants, and endosseous osseointegrated implants were inserted. The results show an adequately deepened vestibulum with no muscle pull around the implants and significantly lower pocket depth after 5 years of follow-up compared with similar studies.

Evaluation of osseointegration of endosseous implants in radiated, vascularized fibula flaps to the mandible: A pilot study

Purpose: This study clinically evaluated the osseointegration of implants placed into vascularized fibula flaps used in mandibular reconstruction of cancer patients following radiation treatment and subsequent hyperbaric oxygen (HBO) therapy. Materials and Methods: Five head and neck cancer patients had mandibular resection and immediate reconstruction with a vascularized fibula flap. Subsequent therapy included greater than 50 Gy of radiation to the fibula flap over a 6 to 8-week period. Two to 6 weeks following radiation therapy each patient received 20 90-minute daily sessions of HBO at 2.4 atmosphere pressure. Stage 1 implant surgery was performed placing two to six implants (15 mm in length and 3.75 to 4.0 mm in width) into each fibula flap. This was followed by 10 postoperative HBO sessions using the previously mentioned protocol. The stage 2 procedure was performed 6 months after the stage 1 procedure. Osseointegration was assessed clinically using manual force and an electronic device at the time the implants were uncovered and monthly over a 6-month period. Results: All 20 implants placed in the fibula flaps were osseointegrated clinically at the time the implants were uncovered and during the 6-month follow-up. Conclusion: In this pilot study, mandibular reconstruction with a vascularized fibula flap and endosseous osseointegrated implants, following radiation of the fibula, was successful. It was concluded that factors such as the graft having its own blood supply and the use of HBO contributed to the successful osseointegration of these implants.

Failures in the osseointegration of endosseous implants

A total of 68 patients, 26 men and 42 women, aged 21 to 86 years, were treated with 204 endosseous implants (TPS, ITI, Bonefit, or Biolox) from 1985 to 1990. They were examined at their latest recall visit approximately 22.5 months after surgery, the range varying greatly between the implant systems used (from 4 to 60 months). Fourteen implants were lost during the observation period because of failures in osseointegration. There were no statistically significant differences in success rates between the implant systems during the observation period. The Periotest values, however, differed between the Bonefit and ITI implants in maxillae (P < .001) and mandibles (P < .01), and between successful and failed TPS implants (P < .001, unpaired t test). In four of the failures, all ITI implants, the prosthetic restorations (fixed dentures and single crowns) had been lost. All other failures were treated by using the previous complete denture. Possible causes of failure included advanced age and poor general health of the patient, complications in the surgical procedures, and compromised oral hygiene.