Endosseous Titanium Implants Research Articles

СТЕКЛОКЕРАМИЧЕСКИЕ ПОКРЫТИЯ НА ДЕНТАЛЬНЫХ ИМПЛАНТАТАХ С БАРЬЕРНЫМИ СВОЙСТВАМИ

Pateks — the technology of applying a biocompatible glass-ceramic coating based on silicon, carbon and nitrogen on dental implants by PECVD is developed by research and production company Plasmacentre and Pavlov University (St. Petersburg, Russia). Purpose of the research — to evaluate the success of optimization of the surface of doped titanium endosseous dental implants which may be achieved with our glass-ceramic barrier coating technology using physicochemical, cytological and spectrophotometric researches. The main task is to carry out a comparative assessment of the studies’ results between dental implants with and without Pateks glass-ceramic coating (doped with titanium alloy). Materials and methods. Titanium implants (grade 5) from BioMed were used in this research. Some of them were coated with Pateks according to our technology. A human lung fibroblast cells culture was used for the cytological study. Spectrophotometric studies were carried out on atomic absorption spectrophotometer and a atomic absorption spectrometer KVANT-Z.ETA (Russia). Findings. Pateks-coated implants demonstrate advantage in comparison with non-coated ones in certain physicochemical parameters such as decrease of defects’ area in the initial surface of titanium implants which is formed on the previous stages of surface shaping and processing, providing higher surface hydrophilicity, increasing of dielectric characteristics and higher pH value. Pateks coating is safe for fibroblast monolayers and does not inhibit respiratory processes in them. Applying of Pateks glass-ceramic coating with a thickness of 0.5 μm reduces the content of aluminum and vanadium ions in the model medium by almost 2 times and pro- vides a barrier that helps to reduce the negative biological effect of these ions on peri-implant tissues.

Functionalization of a clustered TiO2 nanotubular surface with platelet derived growth factor-BB covalent modification enhances osteogenic differentiation of bone marrow mesenchymal stem cells

A multitude of micro- and nano-surface structures have been developed to improve the clinical performance of endosseous titanium (Ti) implants. However, most of these surface structures only simulate the topographic elements on a micro- or nano-scale. In this study, a nano-micro hierarchical TiO2 clustered nanotubular structure was fabricated using anodization, and then functionalized with platelet derived growth factor-BB (PDGF-BB) using PhoA (11-hydroxyundecylphosphonic acid)/CDI (carbonyldiimidazole) chemistry. The resulting 3-dimensional spatial biomimetic structure, named NTPCP, exhibited negligible cytotoxicity and satisfactory bio-activity for host cells, and significantly enhanced the attachment as well as osteogenesis-related functions (early-stage proliferation, extracellular matrix synthesis and mineralization) of human bone marrow mesenchymal stem cells (bMSCs). We observed drastically elevated expression of osteocalcin (OCN), which mirrored prominent bone formation around the NTPCP implants in a rat model. This study establishes a novel strategy to improve the osseointegration of endosseous Ti implants via surface nano-topographic modification and bio-factor covalent functionalization.

Effects of a hydroxyapatite coating on the stability of endosseous implants in rabbit tibiae.

A dental implant surface which would promote rapid and strong osseointegration is a key factor of success in modern implantology. To achieve this goal, different implant surface modifications are developed. A hydroxyapatite (HA) coating changing a bioinert titanium surface into bioactive is one of them. The objective of the study was to investigate the effects on bone osseointegration in rabbits resulting from the application of a HA coating deposited on titanium endosseous implants using a modified electrochemical method. Titanium implants with HA coatings and controls with Al2O3 grit-blasted surfaces were embedded into rabbit tibiae. The chemical composition, roughness and morphology of the implants were determined. Implant stability tests were performed, and the Periotest® value (PTV) and the implant stability quotient (ISQ) value for Osstell Mentor were recorded in order to evaluate the osseointegration. The surface characterization of the implants revealed a microstructure with an arithmetical mean height (Sa) in the range of 0.71-1.04 μm. The HA coating was free of contamination, whereas the controls were enriched with corundum. After healing, a statistically significant increase in the mean ISQ and a decrease in the mean PTV for the HA-coated implants was observed. In the case of the control implants, only PTV decreased significantly with time. The present study found that implant surface properties affected implant stability as determined by Osstell and Periotest measurements. The HA coating reported herein was found to have chemical and physical properties which appear to improve osseointegration compared to grit-blasted implants.

Hydroxyapatite coating on titanium endosseous implants for improved osseointegration: Physical and chemical considerations.

For many years, hydroxyapatite (HA) has been used as a bioactive endosseous dental implant coating to improve osseointegration. As such, the coating needs to be of high purity, adequate thickness, crystalline, and of a certain roughness in order to stimulate rapid fixation and form a strong bond between the host bone and the implant. There are a number of ways of preparing the HA coating, resulting in various coating properties. Herein, we report the preparation of the HA coating using a direct electrochemical method without the need for subsequent heat treatment. The aim of this study was to investigate the physicochemical properties of the HP coating, deposited on titanium implants by a modified electrochemical method. The coating was characterized in terms of surface chemical composition, structure, morphology, coating thickness and roughness. The coating was found to be composed of homogenous HA with Ca/P and Ca/O ratios of 1.62 and 0.35, respectively. No other forms of calcium phosphate were detected. The degree of crystallinity of HA was 92.4%. The surface roughness was moderate (Sa = 1.04 μm) with the coating thickness of 2-3 μm. The scanning electron microscopy (SEM) analysis revealed a uniform, integrated layer of rod-like HA crystals with the longitudinal axes parallel to the implant surface. The coating reported herein was found to have potentially favorable chemical and physical characteristics fostering osseointegration.

Histological and histomorphometric studies of the effects of hyaluronic acid on osseointegration of titanium implant in rabbits

Background: One of the unique prosthesis for tooth or teeth replacement is the dental implant. Our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. One of these natural polymers is hyaluronic acid. Material and methods: Sixty machined surface implants from commercially pure titanium rod inserted in thirty NewZealand rabbits. Two implants placed in both tibia of each rabbit. The animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). For all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml Hyaluronic acid gel). All sections have been stained with Haematoxylin and Eosin then they were histologically examined and assessed for histomorphometric analysis for counting of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (V*). Results: Histological findings for hyaluronic acid- coated titanium implant revealed an earlier bone formation, mineralization and maturation than that in control groups. Histomorphometric analysis for all bone parameters that examined in this study, showed highly significant difference between control and experimental groups in all healing intervals. Conclusion: Commercially pure titanium endosseous implants coated with hyaluronic acid may be osteocoductive thus accelerating healing process and enhancing osseointegration.

Histological and Histomorphometric Studies of the Effects of Hyaluronic Acid on Osseointegration of Titanium Implant in Rabbits

Background: One of the unique prosthesis for tooth or teeth replacement is the dental implant. Our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. One of these natural polymers is hyaluronic acid. Material and methods: Sixty machined surface implants from commercially pure titanium rod inserted in thirty NewZealand rabbits. Two implants placed in both tibia of each rabbit. The animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). For all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml Hyaluronic acid gel). All sections have been stained with Haematoxylin and Eosin then they were histologically examined and assessed for histomorphometric analysis for counting of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (V*). Results: Histological findings for hyaluronic acid- coated titanium implant revealed an earlier bone formation, mineralization and maturation than that in control groups. Histomorphometric analysis for all bone parameters that examined in this study, showed highly significant difference between control and experimental groups in all healing intervals. Conclusion: Commercially pure titanium endosseous implants coated with hyaluronic acid may be osteocoductive thus accelerating healing process and enhancing osseointegration.

Failure torque of ceramic neck titanium implant

Statement of problemDental implants are typically made of titanium. However, with the current systems on the market, the implant neck often shows through the gingival tissues as a black or dark gray line and/or as a grayish discoloration of the peri-implant soft tissue. PurposeThe purpose of this in vitro study was to test a new implant design. The key component of this design is the ceramic shell that covers the polished collar of the tissue-level titanium implant and masks its dark color to mimic natural dentition. The main purpose was to determine the maximum torque for fracturing the ceramic shell and compare it with clinical implant insertion torque value. Material and methodsType 4 commercially pure titanium endosseous implants of 3 different diameters (3.3, 4.1, and 4.8 mm) were used. Porcelain was applied in 0.5-mm thickness to the polished collar of each implant. An axial-torsional universal testing machine was used to twist the implants until failure. The data (n=10) were statistically analyzed by ANOVA and the Tukey honest significant difference test (α=.05). The maximum torque for each diameter group was also compared with the optimum clinical implant insertion torque value of 35 Ncm (control) using a 1-sample t test. ResultsNone of the tested groups had a fractured ceramic shell. Instead, the implant carriers fractured at the maximum torque levels. Therefore, the fracture of the implant carriers was selected as the maximum (failure) torque value. A statistical difference was found for the failure torque between the 3.3-mm diameter and the other 2 diameters (P<.001) although no statistical differences were found between the 4.1-mm and 4.8-mm diameters (P=.106). A statistically significant difference was found between the failure torque of any one of the tested groups and the clinical insertion torque (P<.001). ConclusionsThe ceramic shells did not fracture. Instead, the implant carriers fractured at certain torque levels. These levels were sufficiently higher than the clinical torque values.

FAILURE TORQUE OF A NOVEL CERAMIC-NECK TITANIUM IMPLANT

Statement of problem: Dental implants are typically made of titanium. However, with the current systems in the market, it is common for the implant neck to show through the gingival tissues as a black or dark grey line and/or as a grayish discoloration of the periimplant soft tissue.Purpose: The purpose of this study was to test a new implant design; the ceramic neck implant is a novel implant design for tooth replacement. The key component of this novel design is the ceramic shell that covers the polished collar of the tissue level titanium implant and masks its dark color, which gives an appearance that mimics natural dentition. The main aim was to determine the maximum torque for fracturing the ceramic shell and compare it to clinical implant insertion torque value.Material and Methods: Thirty type 4 commercially pure titanium endosseous implants of three different diameters (3.3, 4.1, 4.8 mm) were used in this study. Porcelain was applied in 0.5 mm thickness on the polished collar of each implant as determined in a previous article. Axial-torsional universal testing machine was used to twist the implants at X N.cm/s until failure. The data (n=10) were statistically analyzed by ANOVA/Tukey test with a significant level α = .05. The maximum torque for each diameter group was also compared to optimum clinical implant insertion torque value of 35 Ncm (control) using one sample T-test (P<.001). Results. None of the tested groups had a fractured ceramic shell at all. Instead, the implants carriers have fractured at certain torque levels. Therefore, the fracture of the implants carriers was selected as the maximum (failure) torque value. There was statistical difference for the failure torque (Mean ± SD) between 3.3 mm diameter and the other two diameters (P<.001) (F=15.6) while no statistical difference was found between the 4.1 mm and 4.8 mm diameters (p=.106). A statistically significant difference was found between failure torque of any one of the tested groups and the clinical insertion torque (P<.001).Conclusions: Ceramic shells did not fracture. Instead, implants carriers have fractured at certain torque levels. These levels were sufficiently higher than the clinical torque values. This means that there are fewer chances that a fracture might happen while inserting the novel ceramic neck implant and/or the abutment.

The effect of implant and abutment diameter on peri-implant bone stress: A three-dimensional finite element analysis

Introduction: Load transfer mechanisms from the implant to surrounding bone and failure of osseointegrated implants are affected by implant geometry and mechanical properties of the site of placement as well as crestal bone resorption. Estimation of such effects allows for a correct design of implant geometry to minimize crestal bone loss and implant failure. Objectives: To evaluate the effect of implant and abutment diameter on stress distribution in the peri-implant area. Materials and Methods: Three-dimensional finite element models created to replicate completely osseointegrated endosseous titanium implants and were used for the purpose of stress analysis. Two study groups that consisting of a regular platform (RP) group and narrow platform (NP) group were used with a standard bone density and loaded using the ANSYS Workbench software to calculate the von Mises and Principal (maximum tensile and minimum compressive) stress. Results: The von Mises, compressive, and tensile stresses in the peri-implant bone were lower in the RP model compared to the NP model. Conclusion: RP model yielded a positive result with regard to lowering of peri-implant bone stress levels, in healthy as well as compromised bone qualities when compared to NP designs.

Current trends in surface textures of implants

Success of implant technology is due to several other factors such as biologic factors, local factors, and clinician and implant-related factors. Dental implant surface technologies have evolved rapidly in the recent times to enhance the bone formation on their surface. Following the placement of the implant, there is a predictable sequence of bone turnover and replacement at the interface that allows the newly formed bone to adapt to the implant surface. Chemical composition of the implant surface can differ markedly due to manufacturing, finishing, thermal treatment, blasting, etching, coatings, and even sterilization procedures. Based on these considerations, a careful control of implant surface composition becomes a relevant procedure to produce high-quality devices. This paper reviews the impact of various macrotopographical, microtopographical, and nanotopographical features at various stages of osseointegration and gauges the relative merits of various current innovations to the surface topography of titanium endosseous implants.

THE CORRELATION BETWEEN BONE DENSITY AND IMPLANT STABILITY

Abstract: Introduction: Long-term studies have documented the successful treatment of edentulous and partially edentulous patients with endosseous titanium implants. Success rates between 81% and 93% have been reported. Successful treatment with endosseous implants is dependent upon a complex relationship of numerous factors. Bone density and implant stability are important factors for implant osseointegration which has been widely demonstrated by several authors. Objectives: This study was designed to evaluate the correlation between bone density estimated by Cone-Beam Computed Tomography (CBCT) and stability of dental implants estimated by resonance frequency analysis using Osstell ISQ. Materials and methods: Ten dentis s-clean tapered implants were inserted in posterior mandibular edentulous spaces in ten adult patients. The bone density of implants recipient sites were determined by density value (HU) using CBCT. And the implants’ stability were determined by quantitative unit called implant stability quotient (ISQ) measured by resonance frequency analysis using Osstell ISQ. Both values were determined immediately post-operatively and on intervals of 3&6 months. Results: The mean implant stability value was 67.3 ± 9.14 immediately post-operatively, then increased on the 3rd month to be 72.3 ± 3.95 & 75.2 ± 5.33 on the 6th month, there was a statistical significant increase. Also the results of the present study showed that the mean bone density value was 827.96 ± 206.85 immediately post-operatively, then increased to 890.67 ± 138 & 1018.0 ± 149.79 on the 3rd and 6th months respectively, there was a statistical significant increase. Conclusion: There was no correlation between bone density and implant stability. Keywords: bone density, implant stability, cone beam CT, resonance frequency analysis..

Development and Applications of Porous Tantalum Trabecular Metal‐Enhanced Titanium Dental Implants

Porous tantalum trabecular metal has recently been incorporated in titanium dental implants as a new form of implant surface enhancement. However, there is little information on the applications of this material in implant dentistry. The purpose of this article is to summarize the contemporary concept on the applications of porous tantalum trabecular metal in implant dentistry. We therefore review the current literature on the basic science and clinical uses of this material. Porous tantalum metal is used to improve the contact between osseous structure and dental implants and therefore presumably facilitate osseointegration. Success of porous tantalum metal in orthopedic implants led to the incorporation of porous tantalum metal in the design of root-form endosseous titanium implants. The porous tantalum three-dimensional enhancement of titanium dental implant surface allows for combining bone ongrowth together with bone ingrowth, or osseoincorporation. While little is known about the biological aspect of the porous tantalum in the oral cavity, there seems to be several possible advantages of this implant design. This article reviews the biological aspects of porous tantalum-enhanced titanium dental implants, in particular the effects of anatomical consideration and oral environment to implant designs. We propose here possible clinical situations and applications for this type of dental implant. Advantages and disadvantages of the implants as well as needed future clinical studies are discussed.

Combined Osteotome‐Induced Ridge Expansion and Guided Bone Regeneration Simultaneous with Implant Placement: A Biometric Study

To evaluate the long-term outcome of a single-step ridge expansion osteotome procedure and implant placement combined with guided bone regeneration in patients presenting narrow maxillary alveolar ridges. During the period 1999 to 2010, 41 patients aged 19 to 77 years (18 males; 23 females) suffering from partial or full edentulism associated with horizontal resorption of the maxillary ridges (2.5-5 mm) were treated using the combined ridge expansion and guided bone-regeneration techniques to obtain an improved bony base for implant placement. Implant survival, bone width measurements, clinical and radiologic implant success, and clinical complications were recorded and analyzed. Achievement of primary stability of the implant was impossible at six sites; these were recorded as failures. In the remaining 35 patients, one hundred sixteen endosseous titanium implants were simultaneously placed. Follow-up time varied between 6 and 144 months (mean 52.4); of these, 36% were followed up for periods of time longer than 60 months. Implant diameter and lengths varied between 3.3 to 4.8 and 12 to 16 mm, respectively. In the 35 successful procedures (one hundred sixteen implants), the overall implant survival rate was 100%. An average gain in ridge width was 3.5 ± 0.93 (p < .0001) and an average enlargement of the buccal bone was 1.91 ± 0.6 (p < .0001). The mean vertical mesial bone loss was 1.81 mm ± 1.07 (ranging from 0.3 to 4.2 mm), and the mean vertical distal bone loss was 1.74 mm ± 1.12 (ranging from 0.4 to 4.5 mm). In eight patients (32%), at least one implant presented bone loss of ≥3 mm. Within the limitations of this study, we suggest that the combined osteotome-induced ridge expansion and guided bone regeneration simultaneous with implant placement is a reliable procedure with reduced morbidity and may offer an alternative in suitable situations.

A novel bio-sensor for registration of biting force in occlusally reactive single mandibular implant overdenture

Mandibular single denture opposed by maxillary natural dentition showed a great problem. However, mandibular implant overdenture treatment has gained considerable recognition. Ten male patients with complete mandibular edentulous arch and opposing arch have full natural dentition. Patients were divided into two groups. All patients received two endosseous titanium implants. In Group I, patients were rehabilitated with conventional implant retained overdentures. While in Group II, Patients were rehabilitated with occlusal reactive implant overdentures. A Novel proposed biosensor was used to measure the amount of biting force on the implant retained overdenture. Quantitative electromyographic (EMG) signals of the masseter and anterior fibers of temporalis muscles were recorded, filtered and directly interfaced with a computer to represent the data graphically. The mean amplitude (μV), turn, and activity were recorded at the baseline and after three months. The results revealed an increase in the muscle activity in group II after three months as compared to group I. Significant difference in bilateral biting force at the premolar-molar area was found between group I and group II after three months. This study concluded that a resilient implant overdenture denture could be a desirable treatment in mandibular overdenture supported by two implants with resilient attachment and opposing natural dentition due to its easy fabrication and durability in use and increased muscle activity.

Implantable Devices: A Review of Current Treatment Modalities

The use of implantable devices as direct adjuncts to orthodontic treatment as compared to the use of conventional dental implants is relatively less in number. Currently, a limited number of such devices are used to aid in orthodontic treatment. The options include conventional titanium endosseous dental implants, palatal implants, titanium miniscrews (also known as micro- or mini-implants), and mini-bone plates. Integration of dental implants or implantable devices into contemporary orthodontic practice has the following possible advantages: Serving as a means of increasing orthodontic anchorage, virtually eliminating patient compliance issues with regard to wearing of appliances, decreasing overall treatment time, and occasionally permitting orthodontic treatments previously thought to be impossible without surgery. This article is a review of the currently available options for use of implantable devices as sources of temporary skeletal anchorage in orthodontics.

Role of surface topography of titanium endosseous implants for improved osseointegration

Osseointegration is the basis of successful endosseous implantology. The process itself is complex, and many factors influence the formation and maintenance of bone at the implant surface. Studies have shown that implant-tissue interface can be influenced by different methods of surface treatment that affect the biologic response to the implant. Methods of surface treatment include alteration of the microstructure and physicochemical parameters of the implant surface.

Significance of dental implants for health care

Nowadays, endosseous titanium implants must be considered as an evidence-based treatment concept for the replacement of missing teeth. The economic evaluation of scientific evidence suggests that patient satisfaction and oral health-related quality of life may be improved by mandibular implant-retained overdentures over conventional dentures. However, despite promising survival rates reported for dental implants, an increase in the prevalence of peri-implant diseases is emerging. Accordingly, concepts for quality management in education, research, and practice are essential to further improve medical care in implant dentistry.

Osteoblast interaction with laser cladded HA and SiO 2-HA coatings on Ti–6Al–4V

In order to improve the bioactivity and biocompatibility of titanium endosseous implants, the morphology and composition of the surfaces were modified. Polished Ti–6Al–4V substrates were coated by a laser cladding process with different precursors: 100 wt.% HA and 25 wt.% SiO 2-HA. X-ray diffraction of the laser processed samples showed the presence of CaTiO 3, Ca 3(PO 4) 2, and Ca 2SiO 4 phases within the coatings. From in vitro studies, it was observed that compared to the unmodified substrate all laser cladded samples presented improved cellular interactions and bioactivity. The samples processed with 25 wt.% SiO 2-HA precursor showed a significantly higher HA precipitation after immersion in simulated body fluid than 100 wt.% HA precursor and titanium substrates. The in vitro biocompatibility of the laser cladded coatings and titanium substrate was investigated by culturing of mouse MC3T3-E1 pre-osteoblast cell line and analyzing the cell viability, cell proliferation, and cell morphology. A significantly higher cell attachment and proliferation rate were observed for both laser cladded 100 wt.% HA and 25 wt.% SiO 2-HA samples. Compared to 100 wt.% HA sample, 25 wt.% SiO 2-HA samples presented a slightly improved cellular interaction due to the addition of SiO 2. The staining of the actin filaments showed that the laser cladded samples induced a normal cytoskeleton and well-developed focal adhesion contacts. Scanning electron microscopic image of the cell cultured samples revealed better cell attachment and spreading for 25 wt.% SiO 2-HA and 100 wt.% HA coatings than titanium substrate. These results suggest that the laser cladding process improves the bioactivity and biocompatibility of titanium. The observed biological improvements are mainly due to the coating induced changes in surface chemistry and surface morphology.

Synergistic responses of superficial chemistry and micro topography of titanium created by wire-type electric discharge machining

Wire-type electric discharge machining has been applied to the manufacture of endosseous titanium implants as this computer associated technique allows extremely accurate complex sample shaping with an optimal micro textured surface during the processing. Since the titanium oxide layer is sensitively altered by each processing, the authors hypothesized that this technique also up-regulates biological responses through the synergistic effects of the superficial chemistry and micro topography. To evaluate the respective in vitro cellular responses on the superficial chemistry and micro topography of titanium surface processed by wire-type electric discharge, we used titanium-coated epoxy resin replica of the surface. An oxide layer on the titanium surface processed by wire-type electric discharge activated the initial responses of osteoblastic cells through an integrin-mediated mechanism. Since the mRNA expression of ALP on those replicas was up-regulated compared to smooth titanium samples, the micro topography of a titanium surface processed by wire-type electric discharge promotes the osteogenic potential of cells. The synergistic response of the superficial chemistry and micro topography of titanium processed by wire-type electric discharge was demonstrated in this study.

Implant osseointegration in the absence of primary bone anchorage: A clinical report

The authors identified no report describing implant primary stability obtained by external fixation as a means to achieve osseointegration in craniofacial settings. This article describes a situation in which an implant was placed without direct contact with the resident bone; primary stability was provided by an external device. An edentulous patient was restored with 5 endosseous titanium implants to support a mandibular fixed prosthesis. An implant placed in the right central incisor position was removed after 48 hours and replaced with a shorter and narrower implant without contact with resident bone. Thus, primary stability for the implant was provided by rigid fixation to the prosthesis rather than by bone anchorage. At recall examinations after 6 and 27 months, all implants, including the implant in the right central incisor position, showed clinical and radiographic signs of osseointegration. Resonance frequency analysis indicated acceptable stability and osseointegration for all implants. Observations of this patient suggest that implant osseointegration can be achieved by providing primary stability using a fixed complete denture. Primary bone anchorage/contact does not appear to be critical to the osseointegration process.