Full arch rehabilitation in patients with atrophic upper jaws with zygomatic implants: a systematic review.

BACKGROUND: The main objective of this systematic review was to present the outcomes of the treatment with zygomatic implants (ZIs) in the rehabilitations of atrophic upper jaw. FINDINGS: An electronic database search in PubMed, along with a manual search, taking into account language and study period, was performed by two observers; any type of clinical trial and series that included the use of ZIs was used. In the search strategy, the following search terms were used: zygom* AND dental (Implant OR implants) AND edentulous NOT (biomechanic* OR finite element) NOT cadaver. The search was limited to English language, full text, and humans. Literature reviews and clinical case reports were not considered. Forty-two articles published between March 2003 and April 2019 were included in this analysis. The cases of 1247 patients were recovered; these patients received 2919 ZIs. Fifty-two ZIs were removed during the follow-up time. The survival rate of these implants was 98.22%, with a minimum follow-up of 1 month and a maximum of 228 months. Different surgical techniques were used to place ZIs; however, the intrasinusal technique was the most used (23 studies). Post-surgical sinusitis was the most common complication reported in the studies (39 cases). CONCLUSIONS: Based on this review, ZIs were commonly used for rehabilitation of patients with atrophic upper jaw. The survival rates presented were high, and the surgical technique is dependent on the professional experience and the local anatomy. However, it needed additional clinical evidence on bone resorption, esthetic outcomes, and physiological characteristics.

Implant and prosthesis survival rates of full-arch immediate prostheses supported by implants with and without bicortical anchorage: Up to 2 years of follow-up retrospective study.

OBJECTIVES: To compare implant and prosthesis survival rates between full-arch immediate prostheses supported by 4 hydrophilic implants with bicortical anchorage and by 5 or 6 hydrophilic implants placed without bicortical anchorage. MATERIAL AND METHODS: The sample was retrospectively selected and comprised completely edentulous patients treated with full-arch immediate prostheses supported by Morse Taper hydrophilic implants. The selected patients were divided into four groups, according to the region of implant placement and type of anchorage. Differences in implant and prosthesis survival rates between groups, as well as the influence of bicortical anchorage on implant primary stability, were verified using Fisher's exact tests (significant at p < .05). RESULTS: The sample comprised 392 implants, 72 were placed in the maxilla with bicortical anchorage, and 85 were placed without. In the mandible, 140 implants were placed with and 95 were placed without bicortical anchorage. The follow-up period was up to 24 months. A 98.8% implant survival rate was observed for the group of implants placed without bicortical anchorage in the maxilla, and of 100% for the other groups. The overall implant survival rate was 99.7% (391 of 392 implants). Prosthesis survival rate was 100% for all groups. No differences were observed between groups with respect to implant and prosthesis survival rates. Significantly higher primary stability was observed for implants placed with bicortical anchorage in both jaws. CONCLUSION: Predictable results and high survival rates were achieved within the period evaluated by the present retrospective study, with immediate full-arch prostheses when only four hydrophilic implants are placed bicortically.

Identification of potential targets for an anticoagulant pectin.

Heparin is a sulfated polysaccharide of animal origin showing excellent anticoagulant properties. Although it strongly inhibits the coagulation cascade, its interaction with multiple sites results in several side effects. An ideal alternative compound should not only possess anticoagulant and antithrombotic activities, but also provide specific binding to components of the coagulation cascade to decrease side effects and facilitate the control of pharmacologic actions in patient's body. In this work, we performed a scan of potential targets for chemically sulfated pectin from Citrus sinensis (SCP) that shows an efficient anticoagulant activity by combining proteomics and molecular docking techniques. Defining the interaction partners of SCP is fundamental to evaluate if its pharmacological side effects can be as harmful as those from heparin. SCP interacts directly with heparin cofactor II, probably favoring its interaction with thrombin. SCP interaction with antithrombin depends likely on its association with thrombin or factor Xa. In addition to the interaction with factors related to homeostasis, SCP may also act on the renin-angiotensin and on the complement systems. BIOLOGICAL SIGNIFICANCE: The knowledge of potential molecular targets of SCP provides clues to understand its mechanism of action in order to guide molecular changes in this compound to increase its specificity.

Anticoagulant activity of native and partially degraded glycoglucuronomannan after chemical sulfation.

Heparin has great clinical importance as anticoagulant and antithrombotic agent. However, because of its risks of causing bleeding and contamination by animal pathogens, several studies aim to obtain alternatives to heparin. In the search for anticoagulant and antithrombotic agents from a non-animal source, a glycoglucuronomannan from the gum exudate of the plant Vochysia thyrsoidea was partially hydrolyzed, and both native and partially degraded polysaccharides were chemically sulfated, yielding VThS and Ph-VThS respectively. Methylation analysis indicated that sulfation occurred preferentially at the O-5 position of arabinose units in the VThS and at the O-6 position of mannose units in Ph-VThS. In vitro aPTT assay showed that VThS and Ph-VThS have anticoagulant activity, which could be controlled by protamine, and ex vivo aPTT assay demonstrated that Ph-VThS is absorbed by subcutaneous route. Like heparin, they were able to inhibit α-thrombin and factor Xa by a serpin-dependent mechanism. In vivo, VThS and Ph-VThS reduced thrombus formation by approximately 50% at a dose of 40 IU/kg, similarly to heparin. The results demonstrated that the chemically sulfated polysaccharides are promising anticoagulant and antithrombotic agents.