Occlusal plane orientation is an important factor in the construction of a complete denture. Occlusal plane could be oriented using landmarks in the mandibular arch as well as in the maxillary arch. In the mandibular arch there are few landmarks which could be used to orient the occlusal plane like the retromolar pad, corner of the lips (lower lip length) whereas the maxillary arch has a number of landmarks, of which the ala-tragal line is the most commonly used and the same being the most controversial. In the following article different landmarks and its accuracy for orientating the occlusal plane in an edentulous subject as studied by various authors has been discussed.
Group AHC, representing a heat-polymerizing resin, showed the highest flexural strength and hardness values as compared to auto-polymerizing resins and light-polymerizing resin.
The results of this study indicated that the occlusal plane was found parallel to a line joining the ala of the nose and the inferior part of the tragus in a slight majority of the participants.
Introduction:Soft denture liners have a key role in modern removable prosthodontics since they restore health to inflamed and abused mucosa by redistribution of forces transmitted to the edentulous ridges. The most common problems encountered using soft denture liners are water sorption and solubility when in contact with saliva or storage media. These problems are associated with swelling, distortion, support of Candida albicans growth, and stresses at the liner/denture base interface that reduces the bond strength.Objective:To evaluate the water sorption and solubility of commercially available acrylic based self cure soft denture lining material (GC RELINE™ Tissue Conditioner) after immersion in three different storage media (distilled water, Shellis artificial saliva, 5.25% sodium hypochlorite disinfectant solution) at time interval of 4, 7, 11, and 15 days.Material and Methods:The study involved preparation of artificial saliva using Shellis formula. A total 45 standardized samples of the material (GC RELINE™) were prepared in disk form (15 mm in diameter and 2 mm in thickness). The study was divided into three groups with storage in Control (distilled water), Shellis artificial saliva, and 5.25% sodium hypochlorite. Samples were dried in a desiccator and weighed in the analytical balance to measure the initial weight (mg/cm2) of the disks (W1). The first groups (15 samples) were placed in 30 ml distilled water (Group A) at 37ºC, second group 30 ml of artificial saliva (Group B) and third group in 5.25% sodium hypochlorite (Group C). Disks were removed from disinfectant after 5 min and placed in 30 ml distilled water. On days 4, 7, 11, and 15, all samples were removed from their containers and reweighed to measure the weight (mg/cm2) of the disks after sorption (W2). The solubility was measured by placing the disks back in the desiccator after each sorption cycle and drying them to constant weight in the desiccator. These values were weight after desiccation (W3). Water sorption and solubility was calculated: 1. Sorption (mg/cm2) = (W2−W1)/Surface area 2. Solubility (mg/cm2) = (W1−W3)/Surface area.Statistical Analysis:Statistical Analysis was done using one way analysis of variance and the intercomparison between each group was done using Tukey's honestly significance difference (HSD) test.Results:Within the limitations of this study it was concluded that water sorption of the GC RELINE™ soft denture liner material was highest in distilled water followed by 5.25% sodium hypochlorite and least in Shellis artificial saliva at 4, 7, and 11 day interval. However, on the 15th day, the results showed maximum water sorption in 5.25% sodium hypochlorite followed by distilled water and least in artificial saliva. The results on solubility showed highest solubility of GC RELINE soft denture liner in artificial saliva followed by distilled water and least in 5.25% sodium hypochlorite at 4, 7, 11, and 15 day interval.Discussion:The least water uptake of the soft liner in artificial saliva was due to its ionic properties...
This study showed that knowledge and awareness regarding dental implants was disturbingly low. The patients had a very minimal and superficial knowledge regarding prosthetic options. Emphasis is placed on the need for conducting and implementing various public awareness campaigns and for establishing counseling centers.
Background
Poly (methyl 2-methylpropenoate) (PMMA) is one of the most widely accepted biomaterials due to its acceptable advantageous but the limitations associated with these materials make them far from being ideal. So, the present study is to achieve desirable flexural strength by reinforcing PMMA with E-glass fiber.
Aim
Determination of flexural strength of PMMA by varying the weight percentage of glass fiber (2.5 wt%, 5 wt%, 10 wt%), and by varying the aspect ratio (3 mm/20 µm, 6 mm/20 µm, 12 mm/20 µm) of glass fiber.
Materials and methods
Specimens prepared using a standard rectangular mold of 62 mm length, 10 mm breadth and 2.5 mm thickness. A total of 60 samples prepared (6 samples in each group) polymer—monomer ratio 2.4:1 by weight used to prepare samples. Flexural strength is tested using universal testing machine Instron. The microstructural analysis using scanning electron microscopy performed in order to understand the fiber matrix bonding. Detailed statistical analysis done by one-way ANOVA.
Results
Highest flexural strength is observed for the PMMA reinforced with 6 mm/20 µm fiber 2.5 wt%.
How to cite this article
Mathew M, Shenoy K, Ravishankar KS. Flexural Strength of E-glass-reinforced PMMA. Int J Experiment Dent Sci 2014;3(1):24-28.
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