A narrative review on techniques of iris replication in an ocular prosthesis.

The disfigurement associated due to the loss of an eye can cause a significant physical and psychological disturbance. Psychological distress among such unfortunate patients can be reduced by providing an artificial eye. Rehabilitating such patients with an ocular defects is the most challenging task for a prosthodontist. The custom-made ocular prostheses are preferred over the prefabricated stock eye shells as it provides intimate contact with the tissue bed, enabling an ideal fit. For an esthetic ocular prosthesis, the precise positioning of an iris is a primary requirement to avoid the squint eye appearance. Various case reports are documented in the literature for centralizing the iris in the prosthetic eye. This review article explores the established methods and techniques for positioning the iris in a custom-made ocular prosthesis.

A method of hollowing the obturator prosthesis and an overview on the pros and cons of the various materials used for hollowing.

Prosthetic rehabilitation of a partial or total maxillectomy with an obturator is the most acceptable treatment option. The hollowing of the obturator prosthesis is beneficial as it reduces the stresses over the underlying and surrounding tissues. A simple technique of fabricating a hollow bulb obturator has been discussed in this article. At the step of the packing of a denture, the hollow wax pattern of the defect area is formed with modeling wax. This hollow wax pattern is filled with water and is allowed to freeze to form an ice block. This ice block is removed from the wax pattern and is interposed between two layers for heat-cured acrylic resin and is then cured. After processing the denture, the water is retrieved by making a small hole in denture base, which is packed after hollowing with a cold cure acrylic resin. A lightweight prosthesis with a uniform thickness was achieved with a readily available and easily retrievable material, i.e., ice.

Comparative Evaluation of the Effect of Chemical Disinfectants and Ultraviolet Disinfection on Dimensional Stability of the Polyvinyl Siloxane Impressions.

CONTEXT: Infection control is an important concept in the present day practice of dentistry. Disinfection of dental impressions is part of the daily routine in a dental clinics. After disinfection, it is important that impressions remain dimensionally stable. AIM: The purpose of this study was to compare the effect of chemical disinfectants and ultraviolet (UV) disinfection on the dimensional stability of the polyvinyl siloxane impressions. OBJECTIVES: The objective of the study is (1) To evaluate the effect of chemical disinfectant (2% glutaraldehyde and 1% sodium hypochlorite) and UV disinfectant on the dimensional stability of polyvinyl siloxane impression material. (2) Comparative evaluation of the dimensional discrepancy between the cast poured from the polyvinyl impressions material, that is subjected to chemical disinfectant and UV disinfectant to that of cast poured from impressions that were nondisinfected. MATERIALS AND METHODS: A customized tray was fabricated to make impressions. Impressions were divided into four groups, 10 samples were disinfected with 2% glutaraldehyde for 20 min, 10 samples were disinfected with 1% sodium hypochlorite for 20 min, 10 samples were disinfected with UV light for 20 min, and 10 samples were not subjected to disinfection which served as control group. All the samples were poured after 30 min in die stone. Measurements were recorded using traveling microscope of 0.001 accuracy. Statistical analysis used in this study was the one-way ANOVA test. RESULTS: The result showed significant dimensional changes in samples disinfected with 2% glutaraldehyde and 1% sodium hypochlorite, whereas samples disinfected with UV disinfectant unit showed no significant dimensional changes when compared with control group samples. Within the chemical groups, impressions disinfected with 1% sodium hypochlorite showed more discrepancy in the dimensions when compared to the 2% glutaraldehyde disinfected group. CONCLUSIONS: UV light disinfectant can be safely used to disinfect impressions as compared to chemical disinfectants in clinical prosthodontic procedures.