Development of a basic root canal treatment (BRT) for primary oral health care--evaluation after one year.

OBJECTIVES: Atraumatic Restorative Treatment (ART) was a major step forward in community dentistry but treatment options for deep carious lesions or pulp involvement still focus on tooth extraction in under-served areas worldwide. To bridge the gap between ART and extraction this pilot study aimed to develop and follow-up a basic root canal treatment for rural dental health facilities in the Republic of The Gambia (West Africa), faced with an environment lacking technical equipment and developing primary oral health care. METHODS: 25 single rooted teeth with acute irreversible pulpitis were root canal treated with a standardised endodontic instrument kit and a specific procedure. A step-back technique was used with intermittent chlorhexidine 0.2% and saline irrigation. Root canal obturation was performed using a single-cone technique with gutta-percha using Grossman's root canal cement. Coronal filling was carried out by using ART. Clinical examinations were documented before treatment, one day, five days, six months and twelve months postoperatively. RESULTS: None of the root canal fillings had to be revised due to postoperative complications. In 9 out of 25 teeth, transitory apical pain disappeared after a few days. After six months, all ART fillings appeared clinically acceptable, two fillings had to be corrected. Four class II restorations and three class IV restorations needed replacement after 12 months. Patients' assessment of health related quality of life improved significantly, especially concerning dental pain, chewing ability and fitness for work. CONCLUSIONS: Preliminary clinical follow-ups showed encouraging results for the basic root canal treatment approach. Longitudinal clinical studies with greater populations are required to substantiate these results. Modifications in the coronal filling technique are preferable to improve the clinical performance of extended ART cavity restorations.

On-chip microlasers for biomolecular detection via highly localized deposition of a multifunctional phospholipid ink.

We report on a novel approach to realize on-chip microlasers, by applying highly localized and material-saving surface functionalization of passive photonic whispering gallery mode microresonators. We apply dip-pen nanolithography on a true three-dimensional structure. We coat solely the light-guiding circumference of pre-fabricated poly(methyl methacrylate) resonators with a multifunctional molecular ink. The functionalization is performed in one single fabrication step and simultaneously provides optical gain as well as molecular binding selectivity. This allows for a direct and flexible realization of on-chip microlasers, which can be utilized as biosensors in optofluidic lab-on-a-chip applications. In a proof-of-concept we show how this highly localized molecule deposition suffices for low-threshold lasing in air and water, and demonstrate the capability of the ink-lasers as biosensors in a biotin-streptavidin binding experiment.

Micro-engineered 3D scaffolds for cell culture studies.

Cells in physiological 3D environments differ considerably in morphology and differentiation from those in 2D tissue culture. Naturally derived polymer systems are frequently used to study cells in 3D. These 3D matrices are complex with respect to their chemical composition, mechanical properties, and geometry. Therefore, there is a demand for well-defined 3D scaffolds to systematically investigate cell behavior in 3D. Here, fabrication techniques, materials, architectures, biochemical functionalizations, and mechanical properties of 3D scaffolds are discussed. In particular, work focusing on single cells and small cell assemblies grown in tailored synthetic 3D scaffolds fabricated by computer-based techniques are reviewed and the influence of these environments on cell behavior is evaluated.