Anchorage Of Implants Research Articles

Register data on cemented arthroplasty : Aproof for cementless fixation?

Hip and knee implants can be either fixated without cement, press-fit, or with bone cement. Real-world data from arthroplasty registers, as well as studies, provide abroad database for the discussion of cemented versus uncemented arthroplasty procedures. What is the recommendation for cemented or cementless anchorage of hip and knee implants based on the current evidence from international arthroplasty registries and meta-analyses? Arecommendation is generated by means of adirect comparison of data from the arthroplasty registries of eight different countries (USA, Germany, Australia, UK, Sweden, Norway, New Zealand, and The Netherlands), the comparison of 22review studies and meta-analyses based on registry data, as well as the evaluation of the recommendation of healthcare systems of different nations. For this purpose, reviews and meta-analyses whose results were statistically significant were selected, as were the annual reports of the arthroplasty registries that were current at the time of writing. For knee endoprostheses, along survival time, as well as alower risk of revision can be achieved with the help of cemented anchorage with antibiotic-laden bone cement. In patients aged 70years and older, cemented anchorage of the hip stem implant significantly reduces the risk of intraoperative or postoperative periprosthetic fracture (times four), this applies both to elective total hip arthroplasties (TEPs) and to hemiarthroplasty after femoral neck fractures. Antibiotic-loaded bone cement significantly (p = 0.041) reduces the risk of periprosthetic infection, especially in patients with femoral neck fractures. Total knee replacement with antibiotic-loaded bone cement is well established in Germany and evidence based. Registry data and meta-analyses recommend cemented fixation of the hip stem in older patients-in Germany the evidence-based recommendations must still be transferred to daily practice.

Hydroxyapatite Thin Films of Marine Origin as Sustainable Candidates for Dental Implants.

Novel biomaterials with promising bone regeneration potential, derived from rich, renewable, and cheap sources, are reported. Thus, thin films were synthesized from marine-derived (i.e., from fish bones and seashells) hydroxyapatite (MdHA) by pulsed laser deposition (PLD) technique. Besides the physical-chemical and mechanical investigations, the deposited thin films were also evaluated in vitro using dedicated cytocompatibility and antimicrobial assays. The morphological examination of MdHA films revealed the fabrication of rough surfaces, which were shown to favor good cell adhesion, and furthermore could foster the in-situ anchorage of implants. The strong hydrophilic behavior of the thin films was evidenced by contact angle (CA) measurements, with values in the range of 15-18°. The inferred bonding strength adherence values were superior (i.e., ~49 MPa) to the threshold established by ISO regulation for high-load implant coatings. After immersion in biological fluids, the growth of an apatite-based layer was noted, which indicated the good mineralization capacity of the MdHA films. All PLD films exhibited low cytotoxicity on osteoblast, fibroblast, and epithelial cells. Moreover, a persistent protective effect against bacterial and fungal colonization (i.e., 1- to 3-log reduction of E. coli, E. faecalis, and C. albicans growth) was demonstrated after 48 h of incubation, with respect to the Ti control. The good cytocompatibility and effective antimicrobial activity, along with the reduced fabrication costs from sustainable sources (available in large quantities), should, therefore, recommend the MdHA materials proposed herein as innovative and viable solutions for the development of novel coatings for metallic dental implants.

IMPROVED MECHANICAL ANCHORAGE OF GAMMA NAIL LAG SCREW IN OSTEOPOROTIC BONE: A BIOMECHANICAL STUDY

A number of techniques have been developed to improve the immediate mechanical anchorage of implants for enhancing implant longevity. This issue becomes even more relevant in patients with osteoporosis who have fragile bone. We have previously shown that a dynamic hip screw (DHS) can be augmented with a calcium sulphate/hydroxyapatite (CaS/HA) based injectable biomaterial to increase the immediate mechanical anchorage of the DHS system to saw bones with a 400% increase in peak extraction force compared to un-augmented DHS. The results were also at par with bone cement (PMMA). The aim of this study was to investigate the effect of CaS/HA augmentation on the integration of a different fracture fixation device (gamma nail lag-screw) with osteoporotic saw bones.Osteoporotic saw bones (bone volume fraction = 15%) were instrumented with a gamma nail without augmentation (n=8) or augmented (n=8) with a CaS/HA biomaterial (Cerament BVF, Bonesupport AB, Sweden) using a newly developed augmentation method described earlier. The lag-screws from both groups were then pulled out at a displacement rate of 0.5 mm/s until failure. Peak extraction force was recorded for each specimen along with photographs of the screws post-extraction. A non-parametric t-test was used to compare the two groups.CaS/HA augmentation of the lag-screw led to a 650% increase in the peak extraction force compared with the controls (p<0.01). Photographs of the augmented samples shows failure of the saw-bones further away from the implant-bone interface indicating a protective effect of the CaS/HA material.We present a novel method to enhance the immediate mechanical anchorage of a lag-screw to osteoporotic bone and it is also envisaged that CaS/HA augmentation combined with systemic bisphosphonate treatment can lead to new bone formation and aid in the reduction of implant failures and re-operations.

The impact of medication on osseointegration and implant anchorage in bone determined using removal torque—A review

Permanently anchored metal implants are frequently used in dental, craniomaxillofacial, and orthopaedic rehabilitation. The success of such therapies is owed to the phenomenon of osseointegration—the direct connection between the living bone and the implant. The extent of biomechanical anchorage (i.e., physical interlocking between the implant and bone) can be assessed with removal torque (RTQ) measurement. Implant anchorage is strongly influenced by underlying bone quality, involving physicochemical and biological properties such as composition and structural organisation of extracellular matrix, extent of micro-damage, and bone turnover. In this review, we evaluated the impact of various pharmacological agents on osseointegration, from animal experiments conducting RTQ measurements. In addition to substances whose antiresorptive and/or anti-catabolic effects on bone are well-documented (e.g., alendronate, zoledronate, ibandronate, raloxifene, human parathyroid hormone, odanacatib, and the sclerostin monoclonal antibody), positive effects on RTQ have been reported for substances that do not primarily target bone (e.g., aminoguanidine, insulin, losartan, simvastatin, bone morphogenetic protein, alpha-tocopherol, and the combination of silk fibroin powder and platelet-rich fibrin). On the contrary, several substances (e.g., prednisolone, cyclosporin A, cisplatin, and enamel matrix derivative) tend to adversely impact RTQ. While morphometric parameters such as bone-implant contact appear to influence the biomechanical anchorage, increased or decreased RTQ is not always accompanied by corresponding fluctuations in bone-implant contact. This further confirms that factors such as bone quality underpin biomechanical anchorage of metal implants. Several fundamental questions on drug metabolism and bioavailability, drug dosage, animal-to-human translation, and the consequences of treatment interruption remain yet unanswered.

Bone Graft and Intraosseous Anchorage of Dental Implants for Reconstruction of the Residual Alveolar Ridge.

Background:Bone grafting aims at better dental implant osseointegration and preserves the remaining alveolar bone in the socket. The success of various bone grafting materials plays a vital role in assessing future implant function.Aims and Objectives:The present clinical trial was aimed at evaluating the results of guided bone regeneration (GBR) with and without the bioresorbable membrane in the dental implant placement.Materials and Methods:The 20 patients were divided into two groups (n = 10). First was Group I- GBR with bioresorbable collagen membrane (BioGide™) and second was Group II- GBR without membrane. Bone gain and bone levels were analyzed for both groups. All the collected data were analyzed statistically.Results:For Group I, bone levels at baseline were nonsignificant (P = 0.2188) Similarly, nonsignificant values were seen in both groups at 3 months with bone level values of 0.25 ± 0.17 and 0.38 ± 0.24 for Group I and Group II, respectively. Changes in the bone levels were found to be 2.45 ± 0.349 and 2.58 ± 0.304 from Group I and II, respectively, inferring the nonsignificant difference with P value of 0.3723. The percentage of bone gain for intergroup at the end of 3 months was 89.15% ±0.678 for Group I and 88.68% ± 0.503%; these values were statistically nonsignificant (P = 0.982).Conclusion:Nonsignificant difference was observed between the two groups with and without membrane in terms of changes in bone level, percentage of bone gain, and bone defect reduction. This study concludes that the use of bone grafts significantly improves residual alveolar ridge irrespective of membrane used.

Effect of insertion factors on dental implant insertion torque/energy-experimental results

Anchorage of dental implants is quantified with a mechanical engagement to insertion, for example maximum insertion torque (MIT) and insertion energy (IE). Good anchorage of dental implants highly correlates to positive clinical outcomes. However, it is still unclear how bone density, drill protocol, surface finish and cutting flute affect anchorage. In this study, effects of the insertion factors on both MIT and IE were investigated using a full-factorial experiment at two levels: bone surrogate density (0.32 g/cm3 versus 0.48 g/cm3), drill protocol (Ø2.4/2.8 versus Ø2.8/3.2 mm), implant surface finish (machined versus anodized surface) and cutting flute (with versus without). Osteotomies were prepared on rigid polyurethane foam blocks with dimensions of 40 × 40 × 8 mm. Screw shaped dental implants with variable tapered body were consecutively inserted into and removed from the polyurethane foam blocks three times under constant axial displacement and rotational speed. Axial force and torque were recorded synchronously. Insertion energy was calculated from the area under the torque-displacement curve. In this study, we found the main insertion mechanics were thread forming for the first insertion. For the second and third insertions, the main mechanics shifted to thread tightening. Maximum insertion torque (MIT) responded differently to the four insertion factors in comparison to IE. Bone surrogate density, drill protocol and surface finish had the largest main effects for first MIT. For the first IE, drill protocol, surface finish and cutting flute were significant contributors. These results suggest that MIT and IE are influenced by different mechanics: the first MIT and the first IE were sensitive to thread tighten and forming, respectively. Together MIT and IE provide a complete assessment of dental implant anchorage.

New approach for the anchorage of nasal implants without osseointegration using the Epiplating system for a magnetic prosthesis.

New approach for the anchorage of nasal implants without osseointegration using the Epiplating system for a magnetic prosthesis.

Relative contributions of implant hydrophilicity and nanotopography to implant anchorage in bone at Early Time Points

To compare the contributions of implant hydrophilicity and nanotopography on anchorage in bone. The effect of elevated calcium surface chemistry on bone anchorage was also investigated. A full factorial study design was implemented to evaluate the effects of ultraviolet (UV) light and/or sodium lactate (SL) and discrete crystalline deposition of nanocrystals (DCD) treatments on the osseointegration of dual acid-etched (AE) titanium alloy (Ti6Al4V) and grit blasted and AE (BAE) commercially pure titanium (CpTi) implants. Sodium hydroxide (NaOH)-treated CpTi implants were immersed in simulated body fluid (SBF) to increase calcium surface chemistry. Implants were placed in the femora of Wistar rats and tested using pull-out testing (BAE implants: 5, 9, 14days) or tensile testing (AE implants: 9days, NaOH implants: 28days). Ti6Al4V-AE implants with DCD- and UV-treated surfaces significantly increased bone anchorage compared with untreated Ti6Al4V-AE alloy implants. Pull-out testing of BAE-CpTi implants with the DCD treatment showed increased disruption force values compared with surfaces without the DCD treatment at 5, 9 and 14days by 4.1N, 13.9N and 15.5N, respectively, and UV-treated implants showed an increase at 14days by 8.4N. No difference was found between NaOH+SBF and NaOH+H2 O groups. Bone anchorage of implants was found to be improved by UV-treating implants or nanotopographically complex surfaces. However, implant nanotopography was found to have a greater contribution to the overall bone anchorage and is more consistent compared with the time-dependent nature of the UV treatment.

Polymeric Biomaterials with Complimentary Role in Joint Endoprosthesis. II. Compositional and morpho-structural analysis

Successfully used in bone surgery for more than 65 years, self-hardening organic cements (CCOs), in particular acrylic cements, are today, the most advanced complementary biomaterials used in articular endoprosthesis. One of the strategies for obtaining of performing anchorage of artificial implants is to develop new acrylic cements with improved physical, chemical and biomechanical characteristics. The aim of this paper was to identify the compositional and morpho-structural changes of acrylic cements induced by the composition of the liquid phase of the material. Such changes influence the potential to generate the physical bonds responsible for fixation and stabilization of endoprosthesis. The samples studied had different compositions due to the mixture of acrylic monomers, methyl methacrylate (MMA) and butyl acrylate (BuA) in the liquid component of cement. The MMA / BuA ratio varied between 1/0 v / v and 1/4 v / v. Changes in the composition and morphology of cement samples have been highlighted by ESCA (Electron Spectroscopy for Chemical Analysis), EDX (Energy-Dispersive X-ray Spectroscopy), IR spectroscopy and SEM images. The obtained data show that minor changes in cement composition can significantly influence morpho-structural characteristics such as pore size and their distribution in the mass of fixing material.

Biomechanical Evaluation of Zygomatic Implant Use in Patients With Different Buccal Maxillary Defect Levels.

The purpose of this study was to examine the biomechanics of zygomatic implants that were planned on an atrophic maxilla with five different buccal defect types and two different bone types. Three-dimensional models of zygomatic implants, human skulls, and maxillary prostheses were modeled with SolidWorks software. Ten finite element models of skulls with five different buccal defect types and two different bone types were constructed to mimic various clinical scenarios. Two bilateral zygomatic implants and two anterior dental implants were inserted into all models. The data were processed by ANSYS Workbench software. 150-N vertical occlusal and 300-N masseteric loads were simulated on a modeled prosthesis. The stresses on and deformations of the bones and implants were then observed and compared. Maximum Von Mises stress was found in skulls modeled with a type 4 defect and D3 bone type. Minimal stress values were found in the skull model with a type 1 buccal bone defect and D2 bone type. Displacement values were correlated with stress values. Cortical bone anchorage and bone type of zygomatic implants positively affect their biomechanics. Alveolar crest support has an effective role in the biomechanics of zygomatic implants.

Osteotome Sinus Floor Elevation Without Grafting: A 10-Year Study of Cone Beam Computerized Tomography vs Periapical Radiography

This article aims to evaluate and compare the 10-year bone anchorage and protrusion of implants into the sinus using cone beam computerized tomography (CBCT) and periapical radiography. Implants (≤ 10 mm) were placed with osteotome sinus floor elevation (OSFE) without grafting in maxillae with bone height ≤ 8 mm. After 10 years, the CBCT analysis showed bone presence at the buccal and palatal implant sides and corroborated the results obtained using periapical radiographs. In the absence of any symptom or complication, the use of two-dimensional radiography is sufficient for routine long-term follow-up of implants after OSFE without grafting.

When is buccal bone mandatory?

The circumferential anchorage of dental implants in bone is an important prerequisites for excellent long-term outcomes. Clinical reality shows that bone is often missing on the buccal aspect of potential implant sites due to bone alterations post extraction. Therefore, bone augmentation is often needed on the buccal aspect, which has 3 goals: (a) provide osseointegration of the inserted implant to withstand the functional loading of this implant over time, (b) provide a sufficient bony contour to support the facial peri-implant soft tissues for esthetic reasons, and (c) avoid the exposure of the micro-rough implant surface to the peri-implant sulcus. The lecture will address these points.

A Review of the Impact of Implant Biomaterials on Osteocytes

In lamellar bone, a network of highly oriented interconnected osteocytes is organized in concentric layers. Through their cellular processes contained within canaliculi, osteocytes are highly mechanosensitive and locally modulate bone remodeling. We review the recent developments demonstrating the significance of the osteocyte lacuno-canalicular network in bone maintenance around implant biomaterials. Drilling during implant site preparation triggers osteocyte apoptosis, the magnitude of which correlates with drilling speed and heat generation, resulting in extensive remodeling and delayed healing. In peri-implant bone, osteocytes physically communicate with implant surfaces via canaliculi and are responsive to mechanical loading, leading to changes in osteocyte numbers and morphology. Certain implant design features allow peri-implant osteocytes to retain a less aged phenotype, despite highly advanced extracellular matrix maturation. Physicochemical properties of anodically oxidized surfaces stimulate bone formation and remodeling by regulating the expression of RANKL (receptor activator of nuclear factor–κB ligand), RANK, and OPG (osteoprotegerin) from implant-adherent cells. Modulation of certain osteocyte-related molecular signaling mechanisms (e.g., sclerostin blockade) may enhance the biomechanical anchorage of implants. Evaluation of the peri-implant osteocyte lacuno-canalicular network should therefore be a necessary component in future investigations of osseointegration to more completely characterize the biological response to materials for load-bearing applications in dentistry and orthopedics.

Bone remodeling and mechanobiology around implants: Insights from small animal imaging.

Anchorage of orthopedic implants depends on the interfacial bonding between the implant and the host bone as well as on the mass and microstructure of peri-implant bone, with all these factors being continuously regulated by the biological process of bone (re)modeling. In osteoporotic bone, implant integration may be jeopardized not only by lower peri-implant bone quality but also by reduced intrinsic regeneration ability. The first aim of this review is to provide a critical overview of the influence of osteoporosis on bone regeneration post-implantation. Mechanical stimulation can trigger bone formation and inhibit bone resorption; thus, judicious administration of mechanical loading can be used as an effective non-pharmacological treatment to enhance implant anchorage. Our second aim is to report recent achievements on the application of external mechanical stimulation to improve the quantity of peri-implant bone. The review focuses on peri-implant bone changes in osteoporotic conditions and following mechanical loading, prevalently using small animals and in vivo monitoring approaches. We intend to demonstrate the necessity to reveal new biological information on peri-implant bone mechanobiology to better target implant anchorage and fracture fixation in osteoporotic conditions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:584-593, 2018.

Assessment of thermal damage in total knee arthroplasty using an osteocyte injury model.

Polymethylmethacrylate bone cement has been widely used for the anchorage of artificial implants in various orthopedic surgeries. Although it is one of the most successful biomaterials in use, excess heat generation intrinsically causes thermal damage to bone cells adjacent to the bone cement. To estimate a risk of thermal injury, a response of bone cells to cement polymerization must be elucidated because of the occurrence of thermal damage. Thermal damage is affected not only by maximal temperature but also by exposure time, temperature history, and cell type. This study aimed at quantifying the thermal tolerance of bone cells for the development of a thermal injury model, and applying this model for the estimation of thermal damage during cement polymerization in total knee arthroplasty. Osteocytes, osteoblasts, and fibroblasts were respectively subjected to steady supraphysiological temperatures ranging from 45 to 50°C. Survival curves of each cell and temperatures were used to formulate the Arrhenius model. A three-dimensional heat conduction analysis for total knee arthroplasty was conducted using the finite element model based on serial CT images of human knee. A maximal temperature rise of 50°C was observed at the interface between the 3-mm thick cement and the tissue immediately beneath the tibial tray of the prosthesis. The probability of thermal damage to the osteocyte, which was calculated using the Arrhenius model, was negligible at a distance of at least 1 mm away from the cement-bone interface. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2799-2807, 2017.

Orthodontic treatment of Class III malocclusion with lower extraction and anchorage with mini implants: Case report

This article reports the case of an adult patient with Class III malocclusion with mandibular deviation to right side and right anterior and posterior crossbite treated by retraction of the lower teeth with the aid of mini implants in the retromolar region on both sides. The patient opted to not perform surgery for correction of facial asymmetry, thus the treatment consisted of asymmetric extraction (34 and 38) and placement of absolute anchorage devices distal to the lower second molars in the retromolar area, which assisted in the distal movement of the lower molars and retraction of the lower anterior teeth through springs and elastic. At the end of treatment, the patient has achieved Class I, except only the right side, which achieved molar ratio Class II. After a follow-up period of 2 years, the results remain stable. In this case in a patient with moderate facial asymmetry, it was possible to restore the smile esthetics only with tooth movement through the use of absolute anchorage of mini implants for distalization of molars and anterior teeth.

Dental implants inserted in native bone: Cases series analyses.

Background:The concept of osseointegration, i.e., the direct anchorage of endosseous implants made of commercially pure or titanium alloy to the bone caused a breakthrough in oral rehabilitation. The identification of factors for long-term survival and success rate are the main goal of the recent literature. Several variables can influence the final result, and in general they are grouped in surgery-, host-, implant-, and occlusion-related factors.Materials and Methods:A retrospective analysis on a large series of dental implants was performed to detect those variables influencing the clinical outcome. In the period between January 2007 and December 2009, 157 patients were operated. A total of 429 implants were inserted. Dental implants are reliable devices to be used in oral rehabilitation.Results:Globally, very few implants were lost at the end of the follow-up period. Slight but significant differences existed among different implants types with regard to peri-implant bone resorption.Conclusion:A better clinical outcome was revealed for Sweden and Martina global implant.

Factors associated with early and late failure of dental implants

Osseointegration is a good indication of the clinical success of titanium implants referring to the direct anchorage of such implants to the surrounding host bone. Despite the high success rate of endosseous dental implants, they do fail. A lack of primary stability, surgical trauma, and infection seem to be the most important causes of early implant failure. Early signs of infection may be an indication of a much more critical result than if the same complications occur later, because of disturbance of the primary bone healing process. Occlusal overload and periimplantitis seem to be the most important factors associated with late failure. Suboptimal implant design and improper prosthetic constructions are among those risk factors responsible for implant complications and failure. This concise review highlights the main causes associated with early and late implant failure, as thorough knowledge of this unavoidable clinical fact is essential in the field of oral implantology.

Intramandibular course of the mandibular nerve; clinical significance for distraction and implantology

Loss of teeth is accompanied with loss of function and therefore reduction of alveolar bone height. Insufficient bone height can jeopardize the anchorage of implants or surgical procedures such as distraction osteogenesis, because of possible mandibular nerve damage. The goal of this investigation was to determine the exact course of the intramandibular nerve in edentulous mandibles. The study samples included 37 dry human edentulous mandibles. A dental CT scan analysis was performed and four cross sectional views were investigated for each mandible. The Cawood classification was used to assess the grade of atrophy. Implantation simulation was performed in every case. There was no bilateral symmetry in edentulous mandibles, whatever the cross-section studied. A rate of 38.7% were classified Cawood class IV, the most common group in edentulous patients. Our study results led us to place the distraction osteogenesis device in the posterior edentulous mandible. Implant placement was not possible in every case. Our findings allow better understanding from the pathway of the mandibular canal close to the first and second molar in edentulous mandibles. This anatomical data and surgical techniques such as implant insertion and distraction osteogenesis allow finding solutions for "mandibular edentulism". Distraction is essential for a successful implantology.

The effect of injectable calcium phosphate cement on bone anchorage of titanium implants: an experimental feasibility study in dogs

Calcium phosphate has high osteotransductive potential. The injectable form of calcium phosphate cement (ICAP) can be used as an adjunctive supportive agent for dental implants. The aim of this study was to assess the effect of an ICAP on the reverse torque resistance of titanium implants. Two implant beds (total 24) were prepared in each proximal tibia of 6 beagles. ICAP was injected into one of prepared implant beds (test) and the implant was inserted. The next implant was inserted without ICAP to serve as control. Three dogs were killed after 2 weeks and 3 after 12 weeks. Retrieved implants were subjected to reverse torque test. Results were analyzed with Student's t-test. Scanning electron microscope (SEM) was used for further evaluation. Mean torque values in 2-week healed implants were 52.48 N cm and 50.57 N cm for test and control implants, respectively (p=0.4). 12-week healed implants showed 81.61 N cm and 76.71 N cm for test and control implants, respectively (p=0.14). Results indicated no statistical difference between test and control implants for either healing time. SEM images of tested samples revealed close contact between the bone-ICAP-titanium surface. ICAP must be tested on further developed experimental models.