Selective uptake and sensing of nitrate in poly(3,4-ethylenedioxythiophene).

Nitrogen (N) as a nutrient, in the form of nitrate (NO3-), is essential for plant growth. Chemical fertilizers are used to increase crop yields, but overuse can lead to forms of environmental pollution necessitating methods to detect and monitor the level of NO3- in-situ in agricultural soils. Herein we report for the first time the NO3- selectivity of the inherently conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT). This selectivity occurs when PEDOT thin films are exposed to an aqueous environment containing not only NO3-, but a mixture of other ions present in concentrations (ppm) typical of real agricultural soil. The PEDOT sensitivity to absorb NO3- from solution is determined to be <1 ppm.

Report of a case receiving full-arch rehabilitation in both jaws using immediate implant loading protocols: a 1-year resonance frequency analysis follow-up.

BACKGROUND: Immediate occlusal implant loading has been documented as a viable treatment option for various indications. However, documentations related to full-arch rehabilitation are usually limited to treatment of one jaw at a time, thereby leaving the opposing dentition unchanged. Furthermore, clinical documentation using traditional, well-accepted measuring techniques may not be adequate when it comes to short-term evaluation of the success or failure of implants subjected to immediate occlusal loading. PURPOSE: The purpose of this case report is to (1) present an implant stability follow-up of a patient receiving an immediate, implant-supported full-arch rehabilitation in both jaws and (2) evaluate the patient's acceptance of this rehabilitation. MATERIALS AND METHODS: A 68-year-old patient scheduled for implant treatment was selected for an immediate implant loading protocol in both jaws. During two surgical events 3 weeks apart, eight maxillary and four mandibular Brånemark System Mk IV TiUnite fixtures (Nobel Biocare AB, Göteborg, Sweden) were inserted and subsequently used to immediately support a cross-arch fixed prosthesis in the maxilla and a bar-retained overdenture in the mandible. Implant stability was recorded from the day of surgery periodically during a 1-year follow-up using resonance frequency analysis (RFA). RESULTS: At the 1-year follow-up, based on clinical, RFA, and radiographic evaluations, all implants and the reconstructions were classified as successful. All maxillary implants showed a decrease in the implant stability quotient (ISQ) value from the measurement at the time of surgery to the first follow-up, whereas two of four mandibular implants revealed an initial drop in stability. Irrespective of a specific ISQ level measured at implant surgery (ISQ range 53-74) and despite an initial decrease in stability, measurements recorded at the 12-month follow-up indicated similar stability levels for all maxillary implants (ISQ range 64-68) or the group of mandibular implants (ISQ range 72-75) but with a higher ISQ level for mandibular implants. Furthermore, the patient's acceptance of the immediate full-arch rehabilitation in both jaws was high. CONCLUSIONS: The present case report demonstrates that a slightly staged approach for full-arch rehabilitation in both jaws using immediate implant loading protocols is a realistic treatment option. Furthermore, RFA follow-up indicates that immediately occlusally loaded implants placed in reduced bone quality and quantity are more prone to loose stability in the early healing period compared with implants placed in dense bone quality.

Immediate occlusal loading of Brånemark TiUnite implants placed predominantly in soft bone: 1-year results of a prospective clinical study.

BACKGROUND: The original Brånemark protocol for dental implant treatment was based on submerged healing prior to loading. However, immediate loading has been reported possible with high success rates for various indications, provided that good bone quality and quantity are present. In many of these studies, machined-surface implants have been used. Recently, a new surface texture has been developed, based on an oxidation processing, that aims to enhance the early bone response (Brånemark System Mk IV TiUnite , Nobel Biocare AB, Gothenburg, Sweden). It has been documented that this surface texture may help to better maintain primary implant stability during the early healing period and that secondary implant stability can be reached earlier compared with results when using a machined surface. Such a positive influence on implant stability might be an advantage when applying an immediate-loading protocol, especially in soft bone regions where a tendency toward reduced success rates has been reported. PURPOSE: The aim of this report was to present the short-term success rates of TiUnite-surfaced immediate occlusally loaded Brånemark System Mk IV implants placed in various regions of the jaws. MATERIALS AND METHODS: Thirty-eight patients received a total of 51 prosthetic reconstructions, all of which were connected on the day the implants were inserted. Of these, 20 were single-tooth restorations, 30 were fixed partial dentures, and 1 was a complete fixed lower jaw restoration. These prostheses were supported by 102 Brånemark System Mk IV TiUnite implants (38 maxillary and 64 mandibular), the majority of which were placed in posterior regions (88%) and mainly in soft bone (76%). Cutting resistance measurements were performed during implant insertion, and resonance frequency measurements were conducted during the course of the study. Furthermore, radiographic examinations were performed in connection with the delivery of the prostheses and at the 1-, 6-, and 12-month follow-up visits. This article reports on the results after 1 year of loading. RESULTS: Three maxillary implants were removed, although stable, in one patient at the 8-week follow-up because of postoperative infection in the adjacent area of guided bone regeneration (GBR). This resulted in a cumulative success rate of the implants of 97.1% after 1 year of prosthetic loading. The mean marginal bone resorption after 1 year of loading was 1.2 +/- 0.9 mm (SD). CONCLUSIONS: The applied immediate loading protocol in combination with a slightly tapered implant and a modified implant surface texture was shown to be a successful treatment alternative even in regions exhibiting soft bone.