Rehabilitation of atrophic maxilla: a review of 101 zygomatic implants

Introduction: Zygomatic implants are a good rehabilitation alternative for upper maxilla with severe bone reabsorption. These implants reduce the need for onlay-type bone grafting in the posterior sectors and for maxillary sinus lift procedures - limiting the use of bone grafts to the anterior zone of the upper jaw in those cases where grafting is considered necessary. Objective: To evaluate the survival of 101 zygomatic implants placed in upper maxilla presenting important bone reabsorption, with a follow-up of 1-72 months. Patients and methods: A retrospective study was made of 101 Zygoma® implants (Nobel Biocare, Göteborg, Sweden) placed in 54 patients with totally edentulous and atrophic upper maxilla, in the period between 1998-2004. There were 35 women and 19 men, subjected to rehabilitation in the form of fixed prostheses and overdentures using 1-2 zygomatic implants and 2-7 implants in the anterior maxillary zone. The principal study variables were smoking, a history of sinusitis, the degree of bone reabsorption, and peri-implant bone loss, among others. Results: The descriptive analysis of the 101 zygomatic implants placed in 54 patients with a mean age of 56 years (range 38-75) yielded a percentage survival of 96.04%, with four failed implants that were removed (two before and two after prosthetic loading). Nine patients were smokers, and none of the 54 subjects reported a history of sinus disorders. Discussion and conclusions: Zygomatic implants are designed for use in compromised upper maxilla. They allow the clinician to shorten the treatment time, affording an interesting alternative for fixed prosthetic rehabilitation. This study confirms that zygomatic bone offers predictable anchorage and acceptable support function for prostheses in atrophic jaws. However, these implants are not without complications. Longer-term evaluations are needed of zygomatic implant survival in order to establish a correct clinical prognosis

Novel micropatterns mechanically control fibrotic reactions at the surface of silicone implants.

Over the past decade, various implantable devices have been developed to treat diseases that were previously difficult to manage such diabetes, chronic pain, and neurodegenerative disorders. However, translation of these novel technologies into clinical practice is often difficult because fibrotic encapsulation and/or rejection impairs device function after body implantation. Ideally, cells of the host tissue should perceive the surface of the implant being similar to the normal extracellular matrix. Here, we developed an innovative approach to provide implant surfaces with adhesive protein micropatterns. The patterns were designed to promote adhesion of fibroblasts and macrophages by simultaneously suppressing fibrogenic activation of both cell types. In a rat model, subcutaneously implanted silicone pads provided with the novel micropatterns caused 6-fold lower formation of inflammatory giant cells compared with clinical grade, uncoated, or collagen-coated silicone implants. We further show that micropatterning of implants resulted in 2-3-fold reduced numbers of pro-fibrotic myofibroblast by inhibiting their mechanical activation. Our novel approach allows controlled cell attachment to implant surfaces, representing a critical advance for enhanced biointegration of implantable medical devices.

Organisational Buying Decision Process for Biodegradable Implants

Työn tavoitteena oli selvittää organisaation ostopäätösprosessi, kun tuotteina ovat biohajoavat kasvo- ja kallokirurgian implantit. Ensin selvitettiin biohajoavien implanttien markkinapotentiaalia, biohajoavien materiaalien lisäksi implanttien valmistuksessa käytettäviä muita materiaaleja sekä implanteilta vaadittavia ominaisuuksia kirjallisuuden ja internetin sekä asiantuntijahaastatteluiden avulla. Kirjallisuuden avulla selvitettiin myös organisaatioiden ostopäätösprosessien yleisiä piirteitä ja vaiheita. Biohajoavien kasvo- ja kallokirurgian implanttien ostopäätösprosessia tutkittiin kirjallisen kyselytutkimuksen avulla, joka oli suunnattu alan asiantuntijoille Euroopassa, Yhdysvalloissa sekä Kanadassa. Tutkimuksessa selvitettiin mm. tärkeimpiä käytettävien implanttien materiaalivalintaan vaikuttavia kriteereitä, ostopäätösprosessiin osallistuvia organisaation jäseniä, sekä heidän roolejaan päätöksenteossa, implantteja koskevan informaation etsintää sekä ostopäätösprosessin vaiheita. Kirjallisuudesta, internetistä, asiantuntijahaastatteluista ja kyselytutkimuksesta saatu tieto koottiin vuokaaviomalliksi, joka kuvaa kasvo- ja kallokirurgian implanttien ostopäätösprosessia organisaatioissa. Lopuksi esitettiin myös ehdotuksia markkinointisuunnitelmaan sekä jatkotutkimusehdotukset.

BS-SEM evaluation of the tisular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes

BS-SEM evaluation of the tisular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes

BS-SEM evaluation of the tisular interactions between cortical bone and calcium-phosphate covered titanium implants

The improvement of the reliability of the contact between the osseous tissues and the implant materials has been tested by recovering the metallic implants with ceramic materials, usually calcium phosphates. In our study, the calcium phosphate recovering layers were deposited by means of a pulsed-laser deposition technique. Our aim was to to evaluate the tissue interactions established between cortical bone and titanium implants covered by five different layers, ranging from amorphous calcium phosphate to crystalline hydroxyapatite, obtained by altering the parameters of the laser ablation process. The surgical protocol of the study consisted in the simultaneous implantation of the five types of implants in both the tibial dyaphisis of three Beagle dogs, sacrificed respectively one, two and three months after the last surgical procedures. After the sacrifice, the samples were submitted to a scheduled procedure of embedding in plastic polymers without prior decalcification, in order to perform the ultrastructural studies: scanning microscopy with secondary and backscattered electrons (BS-SEM). Our observations show that both in terms of the calcified tissues appearing as a response to the presence of the different coatings and of time of recovering, the implants coated with crystalline calcium phosphate layers by laser ablation present a better result than the amorphous-calcium-phosphate-coated implants. Moreover, the constant presence of chondroid tissue, related with the mechanical induction by forces applied on the recovering area, strongly suggests that the mechanisms implied in osteointegration are related to endomembranous, rather than endochondral ossification processes

Relationship between oral cancer and implants: clinical cases and systematic literature review

The use of implants for oral rehabilitation of edentulous spaces has recently been on the increase, which has also led to an increase in complications such as peri-implant inflammation or peri-implantitis. Chronic inflammation is a risk factor for developing oral squamous cell carcinoma (OSCC). Objectives: To review the literature of cases that associate implant placement with the development of oral cancer. Study design: We present two clinical cases and a systematic review of literature published on the relationship between oral cancer and implants. Results: We found 13 articles published between the years 1996 and 2009, referencing 18 cases in which the osseointegrated implants are associated with oral squamous cell carcinoma. Of those, 6 articles were excluded because they did not meet the inclusion criteria. Of the 18 cases reported, only 7 cases did not present a previous history of oral cancer or cancer in other parts of the body. Conclusions: Based on the review of these cases, a clear cause-effect relationship cannot be established, although it can be deduced that there is a possibility that implant treatment may constitute an irritant and/or inflammatory cofactor which contributes to the formation and/or development of OSCC.

Care related pain in rehabilitation after orthopedic trauma: An exploratory study with qualitative data.

OBJECTIVE: Care related pain (CRP) is generally under-estimated and rarely studied in rehabilitation as well as in general medecine. Beliefs about pain influence psychological distress, adjustment to pain and physical disability. In this sense, perceptions of CRP could limit recovery. This exploratory study aims to understand patients' and caregivers' subjective perceptions and beliefs about CRP. PATIENTS AND METHODS: Questionnaires about CRP were submitted to members of the interdisciplinary team of a rehabilitation hospital and to patients with musculoskeletal complaints (cross-sectional design). Twenty patients were also individually interviewed (qualitative data). Four topics were addressed: frequency of CRP, situations and procedures causing CRP, beliefs about CRP and means used to deal with CRP. RESULTS: Seventy-five caregivers and 50 patients replied to the questionnaire. CRP is a very common experience in rehabilitation and it is recognized by both groups. Generally, the situations causing CRP reflect the specificity of rehabilitation (mobilization...) and are similarly perceived by patients and caregivers, with patients considering them as more painful. Beliefs about CRP are clearly different from those usually associated with pain. Both groups point out the utilitarian and the inevitable character of CRP. They differ on that, that patients had a more positive view about CRP. They associate it more often with progress and see it as acceptable at least until a certain limit. They are also able to perceive the richness of means used by physiotherapists to help them coping with CRP. CONCLUSION: Our data may suggest new keys to motivate patient to be active in rehabilitation for example in choosing carefully arguments or words which may fit theirs' beliefs about CRP, or in using various means to manage CRP. Promoting the use of relational competences with chronic pain patients and of a patient-centred approach may also be a concern in training caregivers.

Development and validation of a high performance liquid chromatographic method for determination of cyclosporine-A from biodegradable intraocular implants

An HPLC method was developed and validated aiming to quantify the cyclosporine-A incorporated into intraocular implants, released from them; and in direct contact with the degradation products of PLGA. The separation was carried out in isocratic mode using acetonitrile/water (70:30) as mobile phase, a C18 column at 80 ºC and UV detection at 210 nm. The method provided selectivity based on resolution among peaks. It was linear over the range of 2.5-40.0 µg/mL. The quantitation and detection limits were 0.8 and 1.2 µg/mL, respectively. The recovery was 101.8% and intra-day and inter-day precision was close to 2%.

Avaliação da resistência à corrosão de implantes em aços inoxidáveis ISO 5832-9 e F138 removidos de pacientes

This work has compared the surfaces of two different steel samples used as orthopedical implants, classified as ASTM F138 and ISO5832-9, through optical emission spectroscopy, by means of SEM and EDS. The samples (implants) were also submitted to potentiodynamic cyclic polarization in Ringer lactate and NaCl 0.9 M L-1 solutions; ISO5832-9 sample did not show any kind of localized corrosion, but in the case of F138 steel was observed a pit localized corrosion in both solutions. In Ringer lactate solution it was observed a loss of about 63% for nickel and 26% for iron for F138 stell, compared to the initial composition.

Characterization and in vitro release of cyclosporine-A from poly(D,L-lactide-co-glycolide implants obtained by solvent/extraction evaporation

Cyclosporine-A-loaded PLGA implants were developed intended for ocular route. Implants were prepared using solvent extraction/evaporation technique followed by casting of the cake into rods in a heated surface. XRD patterns showed that cyclosporine-A was completely incorporated into PLGA. FTIR and DSC results indicated alterations on drug molecular conformation aiming to reach the most stable thermodynamic conformation at polymer/drug interface. Implants provided controlled/sustained in vitro release of the drug. During the first 7 weeks, the drug release was controlled by the diffusion of the cyclosporine-A; and between 7-23 week period, the drug diffusion and degradation of PLGA controlled the drug release.