How to cite this article:
Sakurai K, Koike T, Ogami K, Ueda T, Kubo K, Kono T. Change in Retention Force and Angulation Limit of an Attachment System with Silicone Soft Relining Material for Implant-retained Complete Dentures. Int J Prosthodont Restor Dent 2018; 8 (2):40-43.
Aim: We investigated attenuation of the retention force on the female end (silicone soft relining material) with repeated mounting/ removal and determined the allowable angle between the male ends for mounting/removal.
Materials and methods: Attachments consisting of metal ball anchors (diameter 2.5, 2.7, or 3.0 mm) for the male end and a silicone soft relining material for the female end were subjected to retention force measurement and allowable angle tests. The frequency of mounting/removal in 1 year was estimated assuming mounting/removal four times a day. The allowable angle test used two pairs of male ends with the between-male angle set at 0, 15, 30, or 45°, and the angle between the male ends joined with the female end was measured. The retention force at the initiation of the experiment and at each time-point was compared using one-way analysis of variance (ANOVA) followed by Dunnett\'s test (á = 0.05).
Results: The retention forces of the male ends with a diameter of 2.5, 2.7, or 3.0 mm at the initiation of the experiment were 3.8 ± 0.3, 5.2 ± 0.2, and 5.5 ± 0.2 N respectively. After repeated mounting and removal corresponding to use for 1 year, a significant decrease in retention force was noted in all male ends (3.3 ± 0.1, 3.8 ± 0.2, and 4.3 ± 0.1 N respectively). It was also found that mounting/removal was possible up to a betweenmale- end angle of 45°.
Conclusion: Under the conditions of this experiment, the retention force decreased with repeated mounting and removal of the female end prepared with silicone soft relining material. Additionally, a large between-male angle for mounting/removal was allowable, and mounting/removal was possible up to 45°.
Clinical significance: This system may save time and expense and could be used to treat patients easily in their home or a nursing home.
How to cite this article:
Sato Y, Kitagawa N, Terazawa M, Osawa T, Imamura Y. Time-dependent Changes in Occlusal Status in an Implantsupported Prosthesis at the Mandibular First Molar from Prosthesis Placement to 3 Months After. Int J Prosthodont Restor Dent 2018; 8 (2):44-53.
Aim: The purpose of this study was to elucidate time-dependent changes in occlusal status over a 3-month period to understand dynamic factors that act on implant-supported prosthesis. We used pressure-sensitive film for occlusal force diagnostics and silicone testing material to measure the occlusal status of a mandibular first molar implant-supported prosthesis under controlled clenching strengths.
Materials and methods: The subjects were eight patients who had an implant-supported prosthesis inserted at the mandibular first molar and did not have any missing teeth other than the implants. We performed the following tests immediately and 3 months after fitting the prosthesis. First, we monitored masseter muscle activity and defined maximum clenching strength as 100% maximum voluntary contraction (MVC). We then used pressure-sensitive film and a clenching strength measuring device to measure occlusal load and occlusal contact area at clenching strengths of 40, 60, 80, and 100% MVC. Finally, we used silicone testing material and an occlusal contact measurement device to measure occlusal contact area at clenching strengths of 20, 40, and 60% MVC.
Results: Occlusal load and occlusal contact area of the bilateral molar region increased at all clenching strengths 3 months after fitting the prosthesis. However, the quotient of bilateral molar occlusal contact area divided by occlusal load (contact area/ load) showed no significant changes after 3 months for any of the clenching strengths. There was also no significant change observed in occlusal load of the prosthesis, occlusal contact area of the prosthesis and contact area/load significantly
Conclusion: Wearing an implant-supported prosthesis for 3 months increased clenching strength, which increased the overall bilateral molar occlusal contact area and occlusal load. Our findings suggest that implant-supported prostheses increase occlusal contact area at high clenching strengths after 3 months of use.
Clinical significance: This study suggested that implantsupported prosthesis which have ideal occlusal contact status need to be checked and occlusal status adjusted regularly for its prediction.
How to cite this article:
Singh S, Parlani S, Agarwal B, Malaiya A. Evaluation of Flexural Modulus of Flexible Denture Base Material kept in Water, Denture Cleanser, Artificial Saliva, and Open Air for Different Time Intervals: An in vitro Study. Int J Prosthodont Restor Dent 2018; 8 (2):54-58.
Aim: This was an in vitro study done to evaluate the change in flexural modulus of flexible denture base material kept in water, denture cleanser, artificial saliva, and open air for different time intervals.
Materials and methods: The experimental design included four main groups, with each group having three subgroups. A total of 120 specimens were fabricated with each group containing 30 specimens; these four groups, based on duration in the storage condition, were further subdivided into three groups. Group A1: 15 days, group A2: 30 days, and group A3: 60 days.
Results: Flexural modulus of flexible denture in 15 days was found to be highest with denture-cleansing tablet (1246.52 ± 8.69 MPa) and lowest in water (1170.54 ± 7.35 MPa). Flexural modulus of flexible denture in 30 days was found to be highest with open air (1282.94 ± 8.35 MPa) and lowest in denturecleansing tablet (1145.60 ± 5.34 MPa). Flexural modulus of flexible denture in 60 days was found to be highest with open air (1360.34 ± 8.02 MPa) and lowest in denture-cleansing tablet (1120.43 ± 6.34 MPa).
Conclusion: According to our study, flexibility of nylon denture base material decreases when kept in open air and water for prolonged period. Initially, flexibility of nylon denture base material increases in denture-cleansing tablet and in artificial saliva, and later flexibility decreased in the first month, then there was not much effect. The best medium for storage of flexible denture was found to be artificial saliva.
Palatal defects cause multiple problems in speech, mastication, esthetics, and maintenance of oral hygiene. Obturators help in normal deglutition, prevent nasal regurgitation and normal speech production. The fabrication of obturators has been done by various methods in the past using different materials that are incorporated to make hollow bulb, such as modeling wax, sugar, dental stone, and putty. Difficulties have been experienced in removal of these incorporated materials. It is difficult to maintain the form of the hollow bulb and to maintain position of incorporated material as well as the thickness of the heat-cure resin during acrylization. The effect of heat during acrylization is different for different materials. Thus, the final form of the obturator, ease of removal of the incorporated material, and maintenance of hygiene postinsertion are dependent on the material chosen for incorporation in the hollow bulb. This case report describes a novel material for fabrication of a hollow bulb obturator. The fabrication is single stage and easy for the operator.
The eye is one of the vital sense organs. Apart from being a physical disability, the psychological impact can be quite traumatic. The early cosmetic restoration of acquired defects boosts the patient\'s confidence and enhances maintenance of tissue health. The following article describes a technique to customize a prosthesis in a patient of the pediatric age group. Such a fabricated prosthesis adapts better than prefabricated stock prosthesis and the accurate positioning of the iris disk enhances the esthetic outcome.