A new surgical and technical approach in zygomatic implantology.

PURPOSE: Different surgical approaches for zygomatic implantology using new designed implants are reported. MATERIAL AND METHODS: The surgical technique is described and two cases reported. The zygomatic fixture has a complete extrasinus path in order to preserve the sinus membrane and to avoid any post-surgical sinus sequelae. RESULTS: The surgical procedure allows an optimal position of the implant and consequently an ideal emergence of the fixture on the alveolar crest. CONCLUSION: The surgical procedures and the zygomatic implant design reduce remarkably the serious post-operative sequelae due to the intrasinus path of the zygomatic fixtures.

The effect of palm oil addition to the diet of dairy sheep on the immune response.

The aim of this study was to evaluate whether a diet based on palm oil has any influence on the immune response and on the number of eggs per gram of faeces (EPG) of gastrointestinal nematodes (GIN) in dairy sheep. To address this issue, 30 ewes in early lactation were confined and divided into three groups (n = 10) receiving a daily isoproteic and isoenergetic diet. Palm oil was added to the feed at different concentrations: 0% (control; group A), 4% (group B) and 6% (group C). The animals were treated with levamisole 10 days before the beginning of the experiment. Faecal samples were collected and analysed for EPG on day zero of the experiment. On days 60 and 120, individual faecal and blood samples were collected, and the FAMACHA(©) score for assessing clinical anaemia was carried out. The groups receiving palm oil showed a significant reduction in EPG in relation to the control group (A) on day 120. Serum immunoglobulin levels (IgG, IgM and IgE) and proinflammatory cytokine levels (TNF-α, IL-1 and IL-6) were significantly increased on days 60 and 120 (p < 0.05) in groups B and C. Therefore, these results suggest that palm oil stimulates the immune response in sheep, thus reducing EPG of GIN. The hypothesis that palm oil has direct anthelmintic activity should be tested in future studies.

Factors affecting bone response around loaded titanium dental implants: A literature review.

This paper was designed as a review of the knowledge concerning bone adaptation around dental implants. Current literature concerning the biomechanics of bone and titanium dental implants as a main focus and pertinent to key aspects of the review was taken into consideration. Implant stiffness, design and surface were considered as factors affecting bone response to loaded dental implants. The emerging data allows the conclusion that implant design influences force transmission to periimplant bone, but seems to have poor power in preventing time-related marginal bone crest resorption. Mechanical stimulation such as prosthetic stress-dependent strains, affects bone tissue adaptation. Therefore, it is crucial to have high biomechanical control on implants to preserve implant ankilosis and to promote periimplant bone deposition.

In vitro and in vivo follow-up of titanium transmucosal implants with a zirconia collar.

The advantages of transmucosal healing implants with a bioactive zirconia collar as a support for partially fixed prosthodontic restorations are optimal peri-implant marginal tissue sealing, reduction in plaque accumulation and satisfactory aesthetic results. The zirconia used in this study evidenced not only optimal clinical performances, but also good biocompatibility. The results from this study demonstrated that zirconia coating enhances fibroblasts and osteoblast-like cell adhesion, spreading and proliferation, favoring microscopic tissue/cell in-growth and clinical implant fixation improvement. From clinical analysis, it emerged that the treatment group obtained better scores in every peri-implant parameter. This evidence attests faster stabilization of soft and hard tissues around both the transmucosal zirconia collar and at the crestal level of the implant. A reduced plaque accumulation around the implant with zirconia collar could provide a better peri-implant microbiological en-vironment by allowing the soft tissues expression of optimal sealing and good bone adaptation to loading. From these clinical and radiographic comparative analyzes, it emerged that in the treatment group the mean values were always similarly low. A rapid stabilization of both hard and soft peri-implant tissues was documented in the 1st yr. In the treatment group, there was the formation of stable tissue sealing the zirconia collar, which could preserve mucosal and bone levels. In conclusion, 2-yr clin-ical results demonstrated that implants supporting fixed restorations using transmucosal healing implants with a zirconia collar appeared a valid method, reporting 100% implant survival rates. Moreover, in vivo results obtained using strict parame-ters to assess the peri-implant status affirmed that a zirconia collar offers excellent biological acceptance. Our preliminary in vitro results statistically evidenced increased fibroblast and osteoblast adhesion and proliferation to zirconia compared to tita-nium, and an index of enhanced material integration with bone and soft tissue cells. (Journal of Applied Biomaterials & Biomechanics 2004; 2: 143-50).

Morphostructural relationships between bone and implant: comparative analyses by optical microscopy and microradiography.

This study assessed the relationship between the surfaces of a hollow cylindrical titanium implant and the consequent bone organization around it. A human bone maxillary specimen was taken that enclosed an implant which had lasted 28 months under prosthetic loading. The implant was removed because of fracture that prevented the implant from being used as a supporting element for new prosthetic aims. The bone block-section was fixed and embedded, several sections were obtained, and each section was analyzed using three different histologic analyses: optical microscopy under ordinary light and polarized light, and microradiography. Comparative analyses were required on every single section to provide a complete morphostructural analysis of the peri-implant bone. Data retrieved by this research showed the presence of woven bone in the bone layer facing the external implant surface several months after its surgical fitting and functionalization. This finding demonstrates the importance of woven bone, first as holding sheath in the immediate postsurgical stage, and second as a mold for the subsequent centripetal accrementition of secondary lamellar bone.