Antimicrobial properties of green synthesized silver and chitosan nanocomposites.

An eco-friendly and simple approach was carried out for the synthesis of silver-chitosan nanocomposites using Azadirachta indica and fluconazole-mediated aqueous extract. This extract acted as a reducing agent as well as a capping agent for the green synthesis of silver nanoparticles. Chitosan nanoparticles on the other hand were synthesized from the deacetylation of the chitin matrix. To confirm the nanoparticle synthesis, a UV- A visible spectrophotometer was used and FTIR analysis confirmed the presence of functional groups in the prepared extract. The morphological characteristics of silver and chitosan nanoparticles and as nano-composites were studied and confirmed using scanning electron microscopy (SEM) analysis. The synthesized silver-chitosan nanocomposites were subjected to well-loaded agar plates for the evaluation of antibacterial properties against the Streptococcus mutans and Candida albicans for their antifungal properties. The synthesized silver and chitosan nanoparticles showed antibacterial and antifungal activities against common oral micro flora such as Streptococcus mutans and Candida albicans which were measured using the zone of inhibition method. This approach is a one-step, economical and eco-friendly, biocompatible, and effective alternative for nanoparticle synthesis for various prosthetic applications.

Rehabilitation of a mid-facial defect using maxillary obturator with a maxillary expansion device and orbital prosthesis.

Midfacial defects are defined as congenital or acquired defects in the horizontal plane at the middle third of the face and communicate with intraoral maxillary defects. These defects lead to speaking difficulty, difficulty in saliva control and deglutition, mastication, and esthetics. Prosthetic rehabilitation of such defects with maxillofacial prosthesis is a challenging task. Maxillary defects with bilateral undercuts present are common. This case report explains to achieve retention by engaging the bilateral undercuts with the desired path of insertion and obtaining adequate retention of these prostheses. This clinical case report presents prosthetic rehabilitation of a mid-facial defect involving one orbit and the premaxilla region with the help of silicone orbital prostheses and magnets along with an expansion device. This dramatically improved the patient's speech, mastication, deglutition, esthetics, and self-confidence.

Nanoparticles in Prosthetic Materials: A Literature Review.

The commonly used prosthodontic materials are resins, ceramics, metals and silicones. A comprehensive review of literature was completed about the incorporation of nanomaterials in prosthetic dentistry using PubMed and Google Scholar databases. This was supplemented with a manual search of selected journals. English language articles in peer- reviewed journals were selected. Current literature reveals that incorporation of nanomaterials has significantly improved the properties of the prosthetic materials within the clinically acceptable ranges. There appears to be a need for a standardization for these in vitro studies carried out to evaluate their physical, mechanical and antimicrobial properties.

Case Presentation of Two Maxillectomy Patients Restored with Two-piece Hollow Bulb Obturator Retained using Two Different Types of Magnets.

Palatal defect can be repaired by reconstructive surgery and/or a dental prosthesis. We present prosthodontic rehabilitation of two partially edentulous patients, both with surgically induced palatal defect and explains how to achieve the goal for esthetics and phonetics. This also describes the fabrication of a hollow obturator by two piece method, which is simple and may be used as definitive obturator for maximum comfort of the patient. In both the above cases, since the mouth opening is restricted due to surgery, obturator prosthesis is given as two pieces retained with opposite poles of magnet, which facilitates the removal and insertion of the prosthesis.

Comparative study on the tensile bond strength and marginal fit of complete veneer cast metal crowns using various luting agents: An in vitro study.

INTRODUCTION: Several commercially available luting agents are used to cement the dental restorations such as intra-coronal, extra-coronal, and fixed partial dentures. Tensile bond strength (TBS) and accurate marginal fit are the essential factors to determine the good clinical results in fixed prosthesis. The retentivity of the luting cements is assessed by their adhesive capacity over the tooth surface and metal surface. Generally, the adhesive ability has been evaluated with in vitro testing, with tensile bond tests. The failure of fixed prosthesis may be happened as a result of incomplete seating during cementation. Most research on cementation of crowns relates seating failure to the thickness of the cement film. MATERIALS AND METHODS: The study is divided into four groups with 10 samples for each of the luting cement taken up for testing TBS and four groups with 5 samples for each luting agent chosen for assessing marginal fit. The results were tabulated and statistically analyzed. RESULTS: In this in vitro study, the TBS of luting cements, and marginal fit in relation to luting cements were tested by using appropriate testing devices. The TBS of cement is measured using universal testing machine, and the results are tabulated. The marginal gap that exists between the margin of the cast metal crown, and the finish line is measured using travelling microscope before and after cementation. The difference between these two values gives the discrepancy that is due to the film thickness of cement used for luting the restoration. SUMMARY AND CONCLUSION: The TBS value of zinc phosphate cement and glass ionomer cement were found to be almost same. The chemical adhesiveness of the glass ionomer with calcium ions of enamel and dentin may be the attributed reason (ionic bonding). In this study, the polycarboxylate is the one that showed low TBS, and it may be attributed to the weakness of the cement due to reduced film thickness, though this cement has a chemical bonding nature. The observation of results of marginal fit in this study is the increased gap found in zinc phosphate cement followed by resin cement, zinc polycarboxylate, and glass ionomer cement. It is agreeable to estimate the marginal fit of the restoration, which could be affected by the film thickness of the luting cement along with other factors.