v. 07, no. 1
Dental Press Implantology – ISSN 2237-650X
Dental Press Implantol.
v. 07, no. 1
January / February / March
Science and technology are different things!
To think and to know represent the essence of men. Thinking is a prerogative, a right and an obligation that is exclusively human. Knowing is the reason why we exist, and it is not by chance that in Brazilian Portuguese “to know” has the same etymological origin as “to taste”.
True knowledge reaches the reason and the cause of things, not only the things. As man endeavors to exceed the limits of simply knowing something — by means of thinking and reflecting upon that — the basic elements of scientific production emerge: criticism and objectivity.
Science is not the only way to discover the truth; we also have empirical, sensory and other types of knowledge. But scientific knowledge is different because it analyzes, explains, induces and applies the natural law. For being programmed, methodical and sequential, its repeatability is certain. Science necessarily produces public knowledge and provides results that may be repeated by anybody, anywhere. Science is connected to finding the truth, producing new knowledge, but it is also related to the obligation of disclosing it. If it is not public, it is not science.
Science and technology are always together, but many people are not able to distinguish the difference between them, some even think that they are synonyms. In Science & Technology, or simply S&T, we usually find the letter “&” between them. As if they have nothing to do with each other, but they do! Take the Ministry of Science & Technology, for instance.
Technology is connected to the practical application of knowledge and it is associated with progress in daily life, which is a result of scientific knowledge. Technology is also related to manufacture and feasibility as well as commercial, industrial and strategic interests. Science may be useful to technological progress, but not necessarily, as it is committed to knowledge on its own. Technology may be useful to science progress by developing new devices, equipment as well as observation and analysis techniques.
The difference between science and technology may seem subtle, but it is not, and every person could be able to notice it. The progress of mankind depends on science and production of knowledge. Technology, however, is our working tool.
Why does science have to be public while technology does not? Technology is connected to patents and commercial trademarks. Technology is related to the industrial and business world as well as to money. In other words, it is connected to power, profit and the supremacy of some people, cities or companies over others.
When a researcher, scientist or inventor publishes something, he no longer has the right to apply for patents, neither register any brands or other financial and material benefits. Once knowledge has been published, it enters into the public domain. Santos Dumont did not patent the airplane, neither the watch; Röntgen did not patent the X-ray generator, but Nobel patented the dynamite and made a fortune with that. Knowledge that is produced and kept to and by whom it was produced, is useful to itself, to generate profit and power.
A country that wishes to be influential, dominant and wealthy stimulates application for patents and trademarks. There are some international standards used to classify a country according to the number of patents and trademarks it has got. The more patents and trademarks a country has got, the more powerful it is considered among other nations.
When making medicines, cars, guns, toys, computers and nearly everything, a country needs to pay for the rights of patents and trademarks. The more Brazilian researches, companies and laboratories retain the rights over patents and trademarks, the more money we will receive from other countries. That means power and domain. Whether it is good or bad, that is another story. But that is how it works!
In Implantology, when reading a published article, the reader must question its scope — or intention — whether it is scientific or technological! Does the analyzed work display knowledge or it reveals an opportunity for sale or to display a work, protocol or a product? Science and Technology must walk together and have to be licit, but we cannot think that they are synonyms; on the contrary, they are different processes and we must bear that in mind. Let’s think about that.
Dr. Curtis Jansen received his dental degree and a certificate in advanced education in Prosthodontics at the University of Southern California (USC), where he went on to teach in the department of Restorative Dentistry and worked as director of the Implant Dentistry department. He also worked with a dental implant manufacturer in Florida and was extensively involved in the research, design, and development of a number of patented implant restorative components used by major manufacturers today. Dr. Jansen lectures widely and owns a private prosthodontics practice in Monterey, Calif., with an on-site dental laboratory. He spoke with Dr. Bradley Bockhorst, former director of Clinical Technologies at Glidewell Laboratories, Newport Beach, California.
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Surgical strategies for extraction sockets seal
The discovery of the biological phenomenon of osseointegration established treatment options that permanently modified the way to rehabilitate partially or totally edentulous patients. Thus, in this contemporary scenario of the profession, a situation of particular clinical interest is that in which the extraction of a dental element is necessary and the choice for actions to be taken for the most adequate solution of the case is decisive to the patient and to the professional. [...]
Explanation and Application
Where we should analyze bone healing after placement of particulate grafts in surgical bone cavities
Bone healing. Biomaterials. Bone formation.
The evaluation of particulate biomaterial properties used in surgical bone cavities should take into consideration two different environments: first, the events that occur at the interface between particles, the blood clot and the granulation tissue, including osteogenesis; and second, those that occur in the spaces between particles and away from their surface, that is, induced tissue reactions, including osteogenesis. In these spaces, evaluations should include progressive changes in blood clot, granulation tissue and new bone formation. Responses to particulate biomaterials should be evaluated in face of events directly on the surface of the particles, as well as whether these particles will be reabsorbed or not and be replaced with bone to reestablish normal conditions in the site.
Medial mandibular flexure related to biomechanical failures of implant-supported fixed prosthesis with rigid connection distal to the mental foramen
Mandible. Dental prosthesis. Dental implants
Introduction: Some mechanical failures and possible biological problems were related to the medial mandibular flexure in patients who had implant‑supported fixed extensive prostheses, with bilateral rigid connection in implants posterior to the mental foramen.
Methods: Literature research relative to the topic was performed from a query to the MEDLINE database, including papers published from 1954 to 2010. The purpose of this literature review was to compare the possible biomechanical failures of implant‑supported prostheses with extension distal to the mental foramen, such as implant fracture, prosthesis screw loosening or fracture, lack of passive fitting of the metallic structure, bone saucerization, and in some cases, muscle pain and limited mouth opening, and to propose a design to these prostheses.
Conclusion: When the prosthetic planning needs supporting elements at the surface posterior to the mental foramen, the prosthesis should be segmented, especially in the region of the symphyseal area. Thus, the deleterious effects of medial mandibular flexure in the prosthesis and peri‑implant area will be minimized.?
Image and Science
Agenesis of #12 and #22 treated by means of dental implants
A 14-year-old female patient arrived at the clinic, presenting with agenesis of #12 and #22 teeth. Orthodontic treatment was performed with the purpose of improving esthetics and function. When the patient turned 23, she underwent implant placement surgery. As the area where #12 and #22 teeth were showed ridge resorption, alveolar expansion was performed in order to allow a implant with external hexagon to be placed at the ideal tridimensional position. Connective tissue graft was also performed. Custom abutments and zirconia crowns were made with porcelain application. The photograph shows a 12-year follow-up: dental proportions and the interface between the soft tissue and the prosthesis in the implant region are worth noting.
Esthetic excellence in Implantology: The trinomial era
Esthetic advances resulting from the use of dental implants have been some of the major reasons why patients and dentists prefer treatments with implants.
Primarily designed and developed for safe anchorage of prostheses without esthetic concerns, this type of treatment gained larger acceptance when its purpose became the replacement of teeth in areas with great esthetic demands. Recent advances in implant and abutment designs and appearance, as well as the improvement of new ceramic systems, have been fundamental factors in such acceptance. These factors have undoubtedly aggregated esthetic excellence to the treatments with implant-supported prostheses. Therefore, the aim of beautiful prosthetic crowns on adequately placed implants has become feasible and predictable in our daily clinical practice. As a result, the following question is raised: What is the main challenge in implant-supported prosthetic treatments? The answer seems to lie beyond the crown-implant pair.
Subjective assessment of inferior alveolar nerve function after lateralization surgery
Mandibular nerve. Oral surgery. Dental implants.
Introduction: Inferior alveolar nerve lateralization is an option to treat atrophic mandibles whose rehabilitation with prostheses may be limited due to vertical resorption in the posterior region and the short distance between the mandibular canal and the alveolar ridge. This surgery may result in paresthesia and sensory disturbances along the nerve path.
Objective: To evaluate inferior alveolar nerve function and patient satisfaction after lateralization.
Methods: Twenty lateralization procedures were performed together with immediate placement of 52 implants. The same surgeon operated on all patients following a standardized surgical protocol. Six months after surgery, the patients answered a questionnaire about sensory changes after surgery and satisfaction with the results of the procedure.
Results: All patients reported initial transient sensory disturbances and improvement at a mean 45 days after surgery, and some reported improvement after the third day. One had not recovered completely after 6 months. Despite sensory changes, all patients would undergo the procedure again if necessary and would recommend it to others.
Conclusions: Inferior alveolar nerve lateralization seems to be safe and predictable, with minimal and reversible sensory changes and no significant damage to patients when performed according to a standardized surgical protocol.
The importance of keratinized mucosa and implant location on the bleeding on probing around osseointegrated dental implants
Dental implants. Dental plaque. Periodontal index. Mucositis.
Objective: Our objective was to determine the association between the width of keratinized mucosa (KM) and implant location with the bleeding on probing (BOP) status of the soft tissue around osseointegrated implants.
Material and Methods: A total of 172 patients, presenting 635 functioning dental implants was examined. The width of KM, the implant location and the associations of these analysis were divided into four groups. G1 - anterior area with KM ≥ 2 mm, G2 - anterior area with KM < 2 mm, G3 - posterior area with KM ≥ 2 mm and G4 - posterior area with KM<2 mm.
Results: There was no statistical significance in any assessment (p > 0.05).
Conclusion: The width of KM and the location of an implant have no influence on bleeding on probing around dental implants.
The use of short implant as a treatment option in a region of the maxilla with reduced bone height
Short implant. Bone graft. Osseointegration.
Dental implants have been a safe option in oral rehabilitation. The short ones, under 10 mm, are used in clinical situations with great bone resorption after dental loss, instead of a bone grafting process. The present study consists in the case report of #15 tooth loss 17 years ago, and the subsequent deficit in residual bone volume. Among the possible treatment options with dental implants, it were presented to the patient: bone grafts and installation of conventional size implants; and the short implants. For being a more conservative option, with lower morbidity, lower cost and reduction of treatment period, the short implants became the patient’s choice. Many papers have reported high index of success with short implants, considering the importance of bone quality, implant diameter, geometry, design, and surface treatment. This technique might be a good treatment alternative for areas where the volume bone is reduced. However the success of this type of treatment is related to the performing a judicious planning.>
Surgical expansion of the alveolar ridge with immediate implant installation
Alveolar ridge expansion. Maxillary sinus. Dental implants.
Introduction: After tooth loss, the alveolar process undergoes gradual atrophy, making rehabilitation with dental implants impossible, in extreme cases.
Objective: To report a clinical case of immediate implant placement in atrophic edentulous maxilla, after application of the alveolar ridge expansion (ARE) surgical technique in the anterior region and maxillary sinus floor lift (SL) in the posterior regions, along with autogenous bone graft removed from the ascending branch of the mandible.
Conclusion: ARE and SL are viable, safe and predictable alternatives for increasing the thickness and height of the alveolar ridge with rehabilitation purposes.
Comparative finite element analysis of stress distribution in pilars of fixed dentures supported with tilted versus nontilted posterior implants
Vertical implants. Tilted implants. Finite element analysis.
Introduction: According to the all-on-four treatment concept, tilted posterior implants reduce distal cantilever length.
Objective: By means of three-dimensional finite element analysis, to elucidate the biomechanics of these devices and evaluate the use of tilted versus nontilted posterior implants and angled abutments in the treatment of the edentulous jaws.
Methods: Four three-dimensional mandible models were created to simulate cortical and cancellous bone. The models received four parallel implants with straight abutments, or two vertical implants and two posterior implants titled at 17 or 30 degrees with straight or angled abutments. All models received axial loading or off-axis loading on one or both sides of the prosthesis.
Results: The greatest stress concentrations were found for vertical implants and angled abutments. Tilted posterior implants favored stress distribution.
Conclusion: The all-on-four treatment concept and the use of straight abutments favored the biomechanics of implant-supported full dentures.
Abstracts of articles published in important Implantology, Prosthodontics and Periodontics journals from around the world
Europerio 7 Abstracts - Parte II