v. 06, no. 2
Dental Press Implantology – ISSN 2237-650X
Dental Press Implantol.
v. 06, no. 2
April / May / Jun
Every day, bone biology supports clinical practice and implants are improved to optimize the relationship with the tissues, cells and molecules. As an example, there is a series of works by Márcio Borges Rosa, Tomas Albrektsson, Carlos Eduardo Francischone, Humberto Osvaldo Schwartz Filho and Ann Wennerberg on the micrometric characterization of surfaces.
The osteocyte increasingly assumes the role of primary cell or element of fundamental importance in the regulation of bone biology, as it is discussed in the section Explanations and Applications. On the other hand, the role and implications of BMP in Implantology were explored in Ask the Expert section, with “Guidelines for clinical use of BMP”.
The present edition is characterized by the variety of information-rich works, applied to the clinician and clinical practice. Plus, to the delight of the eyes and induction to reflections, we have a picture of the Image and Science section and the selectivity of the Observatory on literature.
In the III International Congress of Implantology, from September 13th to 15th, we will live with many of our collaborators revealing closely their latest findings and discuss them with experts and other researchers. It will be a great opportunity to experience this scientific environment. In late May, we’ll also have the II Regional Meeting of Osseointegration to attend in Salvador. This meeting represents a preamble, with its theme on Osseointegration Scientific Evidences: Paradigms and challenges.
Let’s enjoy this!
Carlos Nelson Elias
Historically, and by definition, Dentistry is a profession belonging to the health sciences, which takes care of human health, studies and treats the stomatognathic system, comprising the face, neck and oral cavity, including bones, masticatory muscles, joints, teeth, tissues, vessels and nerves.
Engineering is a profession that is part of the exact sciences, to acquire and apply mathematical, scientific and technical knowledge in the creation, development and implementation of utilities, such as materials, structures, machines, devices, systems or processes that perform a particular function or purpose. In creation processes, development and implementation, Engineering combines many expertise in order to enable the utilities, taking into account society, technology, economy and environment.
As in Dentistry, Engineering is also a very comprehensive science, comprising a range of more specialized branches, each one with a more specific emphasis on certain fields of application and certain types of technology.
In Brazil, over the past 20 years of osseointegration, it has been observed a marked and growing association between these two distinct areas, making Dentistry and Engineering to exchange information and use cross-terminologies to name, define and better understand some classic phenomena widely studied in literature.
Dental Press Implantology brings to this interview one of the greatest scholars, competent professional and responsible for this healthy interaction: The Metallurgical Engineer, MSc and PhD in Materials Science from the Military Institute of Engineering (IME), a scientist and researcher, Prof. Dr. Carlos Nelson Elias. He discusses various issues related to the Brazilian Dentistry and contemporary Implantology, where he has played an important role and still participates decisively in the development of materials, designs and surfaces of implants used in the national market. An enlightening exhibition revealing the great history of osseointegration in Brazil.
He is, currently, an Associate Professor of IME, twice selected as “Scientist of the state of Rio de Janeiro” (2004 and 2008), a researcher at the Research Foundation of the State of Rio de Janeiro (FAPERJ) and fellow researcher level 1C of the National Council for Scientific and Technological Development (CNPq). Dr. Carlos Nelson Elias is also collaborator of the courses of Orthodontics – UFRJ, Endodontics – UERJ, Metallurgy – UFF and Endodontics – Estácio de Sá. He has experience in Metallurgy and Materials Engineering, with an emphasis in Physical Metallurgy, working on coronary stents, dental materials, development of dental implants, surface modification of dental implants, endodontic instruments, orthodontic appliances, coloring of titanium and simulation.
Our interviewee has 185 articles published in scientific journals, one book, 17 book chapters, 230 papers presented at national and international conferences, 40 from MSc and 14 from PhD. Consultant of the journal Acta Biomaterialia, American Journal of Orthodontics, Clinical Implant Dental Research, Implant News, Indian Journal of Dental Research, Journal of Biomedical Materials Research Part B, Journal of Mechanical Behaviour of Biomedical Materials, Journal of Nanomedicine, Materials Research, Materials Science and Engineering: C, Revista Brasileira de Engenharia Biomédica, Revista Gaúcha de Odontologia, Surface and Coating Technology. Besides having a patent application in the Brazilian PTO, related to the surface treatment of implants.
With this vast experience, it is common to hear in the background of the Brazilian Implantology that the recognized researcher and professor Dr. Tomas Albrektsson (University of Gothenburg) is to Sweden and to the world as respected as the researcher and professor Dr. Carlos Nelson Elias (Military Institute of Engineering – IME) is to Brazil and to the world. Science and research are thankful to them!
Luiz Rogério Duarte
Explanations and Applications
Osteocytes: On the central role of these cells in osseous pathobiology
Osteocytes. Mechanotransduction. Bone biology. Sclerostin. RANKL.
The main targets for the comprehension of bone pathobiology were focused in osteoblasts and clasts, but in recent years it has shifted to the osteocytes — as mechanotransductors of the bone tissue, from the three-dimensional network, by interconnecting its extensions linking a cell to other 20 to 40, like a neural network. By mechanotransduction and from mediators as sclerostin and RANKL, the osteocytes may influence bone pathobiology by interfering with the activity of osteoblasts and clasts. When more bone is necessary, osteocytes release less sclerostin, when it is necessary to inhibit bone formation, osteocytes release more sclerostin. RANKL is connected to local osteoclastogenesis in order to have more cells capable of reabsorbing the mineralized matrix. New therapeutic ways of controlling the metabolic bone diseases have been targeted at these mediators. Studying the presence and the specific effects of sclerostin and RANKL in osseointegration can lead to greater detailing of their biological phenomena.
Ask the Expert
Orientations for clinical use of BMP
What is the origin of BMPs and how extensive is the synonymy employed to identify them?
The morphogenetic proteins of the bone are responsible for signaling to induce bone formation. BMPs (bone morphogenetic proteins) represent a family with more than 20 reported proteins, which are part of the transforming growth ß factor family (TGF-ß), activating and inhibiting the differentiation and growth factors (GDF). They are involved in embryonic development and in the formation of the skeleton. Since the work of Urist3 in 1965, demonstrating that the demineralized bone matrix could induce the formation of cartilage and bone in ectopic sites, many researchers have endeavored to clarify the activity of matrix components.
Influence of external geometry of Morse dental implant on stress distribution
Computer simulation. Dental implant. Finite element analysis.
Objective: To evaluate two proposals of external geometry of dental implants observing the influence on the stress distribution.
Methods: It was performed the evaluation by finite elements of prototypes of dental implants with different external geometric shapes submitted to different conditions of loading (axial, inclined to 15° and inclined to 30°).
Results: The stress increased as the loading became more inclined. The conical geometry showed itself more stable and transmitted less stress to the bone. Conclusions: I) The system with conical dental implant transmits lower stress to the bone and to the dental implant; II) the safety factor of the implants is high suggesting it supports loadings more aggressive in intensity and direction; III) as the loading becomes more inclined, i.e., the components of the lateral forces increase, the stresses on the bone and on the prosthetic components increase; IV) for all simulations, the systems behaved appropriately so there is no indication of deformation or fracture on the prosthetic components or even bone resorption due to overload.
Micrometric characterization of implant surfaces of the five largest companies in the Brazilian market. Part II: Biomet 3i BoneLike implants
Dental implant. Brazilian implants. BoneLike implants. Implant surface. Roughness.
Introduction: The quality of the bone-implant interface is directly influenced by implant surface roughness and a roughness average, with the Sa between 1 to 2µm, has demonstrated better clinical and laboratory results. In Brazil, are installed more than two million implants per year, where 79% are manufactured by domestic companies. However, very little is known or published about the characterization of surfaces of these implants, on the micrometer level.
Objective: The aims of this study are to evaluate and characterize numerically the surface of the implants BoneLike, of Biomet 3i do Brasil company, one of the five largest companies in the Brazilian market.
Methods: Were evaluated a total of 6 implants, purchased directly on the market, of two different designs (BoneLike-HE and BoneLike-CM) and different batches, using light interferometry. Were performed 9 measurements randomly chosen for each unit, 3 on the tops, 3 on the valleys and 3 on the flanks of the threads. The same pattern was followed for evaluation by scanning electron microscope.
Results: The analyzed implants from this company showed Sa values of 0.47µm for BoneLike-HE and 1.01µm for BoneLike-CM. Comparing the batches, both designs showed statistically significant differences between them.
Conclusions: The roughness values found herein categorize the surfaces of BoneLike–HE implants as smooth, and BoneLike–CM implants as moderately rough, with Sa values quite close to a smooth surface.
Influence of tissue biotype in the morpho-esthetic-functional behavior of the peri-implant tissue: A literature review
Dental implant. Biotypology. Periodontics.
Introduction: The current focus of Implantology is the planning of a rehab contemplating, besides the function, the esthetical success. The expectation is to create an esthetic restoration that is indistinguishable from the natural tooth, as well as returning the contour of peripheral structures (peri-implant mucosa and papilla) that resemble the same contralateral structures. It is a field of multiple variables in which the identification of tissue biotype is a factor that competes for the achievement of such success.
Objective: The purpose of this present work was to review the influence of gingival biotype on morpho-functional and esthetic behavior of peri-implant tissues, indicating protocols of diagnosis and management of these tissues. It was used as source of research the data base of PubMed, selecting articles published from March 2008 to June 2011.
Conclusion: Within the limits of this review, it was possible to conclude that tissue biotype has influence on the esthetic in the therapy with implants, specially on the facial peri-implant mucosa levels; presenting the thin biotype greater susceptibility to recession. In this condition, the conversion of a thin biotype into a thick biotype, through grafting of conjunctive tissue seems to positively influence on the level of facial marginal mucosa. On the other hand, the tissue biotype showed little influence on the height of the interproximal papilla.
Determining the prognosis: When to treat and when to extract?
Prognosis. Dental implants. Prosthesis and implants.
Introduction: The advent of implants revived the discussion of one of the great dilemmas of clinical dentistry, which is the identification, based on prognosis, of when a tooth must be extracted or when other treatment options can be considered. Periodontal, endodontic and restorative characteristics must be carefully evaluated to determine prognosis and treatment predictability and consequent development of the treatment plan. Objective: Due to the relevance of this topic, the objective of this work is, by means of a literature review, to assist the dentist in evaluating clinical situations requiring decision making between keeping or extracting a tooth, establishing a correct prognosis.
Results: Findings in the literature show that authors disagree among more conservative approaches and implant placement. Factors that can distinguish those cases are the technical and scientific knowledge and professional experience, commitment to their patient’s oral hygiene, as well as its systemic, dental and financial conditions. However, there is a consensus in the literature regarding the sovereignty of one technique over another for the treatment of different clinical situations.
Conclusion: What will guide the clinician’s choice is a critical and scientific analysis of the cost-benefit to establish an individualized, multidisciplinary and with greater predictability treatment plan.
Innovated approach in late failure of osseointegrated implant: Minimally traumatic implant explantation (Part 1)
Dental implants. Retreatment. Device removal.
Introduction: The minimally traumatic retrieval implant technique is a treatment that uses a tapered screw counterclockwise device. This tool can break the osseointegration and retrieve the implant easily.
Objective: The aim of this paper is to show a clinical case report where this technique was used in implant failure and to show the advantages and disadvantages of other treatment alternatives.
Conclusions: This new approach suggests that this explantation can preserve the peri-implant bone tissue and the adjacent teeth, there is a reduction of treatment time and in the morbidity associated with bone reconstruction. It seems an effective technique for removal of implants, ensuring predictability to retreatment.
Presentation of a model of periodontal clinical record
Clinic form. Periodontics. Periodontitis. Data analysis.
Introduction: The clinic form is an essential tool for the execution of any periodontal procedure. Its finality is to obtain and record as much information as possible about the patient’s general and oral state of health, besides storing records of all executed procedures since initial appointment until the treatment conclusion.
Objective: The purpose of this work is to emphasize the importance of the periodontal clinic form and propose a guidance model for professionals and institutions on the elaboration of their own clinical forms.
Methods: Through the analysis of the data contained on clinical forms of several institutions and study of the main articles related to the subject it was created an specific model of clinical form for Periodontics.
Image and Science
Crown cementation over implant
We evaluate our clinical everyday under various clinical aspects, using our ability to achieve maximum technical details and turning them into actual art capturing the moment by means of photography. Photograph data:
» Canon EOS Rebel T1i
» Focal length: 55
» F: 13
» Exposure Time: 1/320’