Dynamic Mechanical Properties of Maxillofacial Materials

Six maxillofacial materials were evaluated by determining their dynamic properties with use of a Goodyear Vibrotester. The dynamic modulus, internal friction, and dynamic resilience were measured for all materials over a temperature range of -15 to 37 C. The dynamic modulus ranged from 11.1 to 124.8 kg/cm2 and the dynamic resilience varied from 1.1 to 63.5%.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67192/2/10.1177_00220345750540062001.pd

Stain Removal from a Silicone Maxillofacial Elastomer

In this study, environmental stains were removed from maxillofacial elastomers by solvent extraction. Silastic 44210, an RTV silicone with proven color and physical property stability, was stained with lipstick, disclosing solution, and methylene blue. These stains were then removed by solvent extraction with each of four chemically dissimilar solvents, namely: toluene, benzene, 1,1,1-trichloroethane, and n-hexane. An additional series of samples was prepared with 11 maxillofacial pigments, not for staining, but for evaluation of pigment stability. Results obtained from spectrophotometric measurements before and after solvent extraction demonstrated the effectiveness of solvent extraction in removing stains, while there was little or no change in the color of the pigments or the base elastomer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66797/2/10.1177_00220345810600100501.pd

Outbreak of Aeromonas hydrophila associated with the parasitic infection Ichthyophthirius multifiliis in pond of African catfish (Clarias gariepinus) fingerlings at Sebeta, Ethiopia

Outbreak of a disease was observed on African catfish (Clarias gariepinus) fingerlings manifested by white nodules all over the body and hemorrhage in the skin that occurred on June 20, 2011 in an earthen pond at Sebeta, Ethiopia. The outbreak was investigated by using a combination of methods that included clinical observations, gross and histopathology examination and bacterial isolation. On histopathological  examination co-infection of Aeromonas hydrophila with Ichthyophthirius multifiliis a holotrichous ciliate, was found to be the cause of the outbreak. In order to control the outbreak, the fish density was reduced and the fish were removed and treated with sodium chloride (3%) and moved to another properly disinfected pond that contains fresh and good quality water. The former pond was drained and left empty for two  weeks to dry and then lime was added over it before filling it with water. The sick fish got cured after three weeks and no new case was observed; which may be due to development of immunity or the intervention measures taken to control the problem. This intervention protocols need to be further investigated in a properly designed experiment as a possible control of co-infection of these two pathogens in catfish  fingerlings.Keywords: Aeromonas hydrophila, Co-infection, Ethiopia, Ichthyophthirius multifilii

Color Stability of a Pigmented Elastomer for Maxillofacial Appliances

The color stability of a series of eleven maxillofacial pigments was determined after accelerated aging using reflection spectrophotometry. The results indicate that seven of the pigments demonstrated good to excellent color stability, while four of the pigments were less promising for clinical use.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67027/2/10.1177_00220345790580050301.pd

Elastomers for maxillofacial applications

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23271/1/0000208.pd

Physical property comparison of 11 soft denture lining materials as a function of accelerated aging,

Soft denture-lining materials are an important treatment option for patients who have chronic soreness associated with dental prostheses. Three distinctly different types of materials are generally used. These are plasticized polymers or copolymers, silicones, or polyphosphazene fluoroelastomer. The acceptance of these materials by patients and dentists is variable. The objective of this study is to compare the tensile strength, percent elongation, hardness, tear strength, and tear energy of eight plasticized polymers or copolymers, two silicones, and one polyphosphazene fluoroelastomer. Tests were run at 24 hours after specimen preparation and repeated after 900 hours of accelerated aging in a Weather-Ometer device. The data indicated a wide range of physical properties for soft denturelining materials and showed that accelerated aging dramatically affected the physical and mechanical properties of many of the elastomers. No soft denture liner proved to be superior to all others. The data obtained should provide clinicians with useful information for selecting soft denture lining materials for patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31019/1/0000695.pd

A qualitative study of primary health care access, barriers and satisfaction among people with mental illness

Research has found that a substantial proportion of individuals with mental illness have high morbidity and mortality rates, and high under-diagnosis of major physical illnesses. Furthermore, people with a mental illness tend not to seek out or utilise health care services. The reasons for the negative attitudes and behaviour towards health care services among this population have not been investigated. This paper presents findings from a study that investigated the health care service needs of people with mental illness (n = 20), and views from health care providers (n = 16) regarding access to these services by people with a mental illness. Results indicated that psychiatric patients identified a range of barriers to their health care usage and low levels of health care satisfaction. These views were shared with health care professionals. Reasons for these findings and strategies to address these problems so that there is better access to health care services for people with mental illness are discussed. <br /

Response to serotonin reuptake inhibitors in OCD is not influenced by common CYP2D6 polymorphisms

The cornerstone of pharmacotherapy for OCD is serotonin reuptake inhibition, either with clomipramine or with selective serotonin reuptake inhibitors (SSRIs). In spite of the success of serotonin reuptake inhibiting drugs, nearly half of OCD patients do not respond to treatment. Treatment response may be affected by genetic polymorphisms of the P450 metabolic system. The four most common enzyme-activity reducing polymorphisms of the P450 CYP2D6 enzyme were determined in 91 outpatients with primary OCD according to DSM-IV criteria, receiving dosages titrated upward to 300 mg/day of venlafaxine or 60 mg/day of paroxetine, using a fixed dosing schedule. Our results show that the investigated CYP2D6 polymorphisms are not a decisive factor in the response to paroxetine and venlafaxine treatment in OCD in spite of their highly significant effect on the blood levels of these medicines

Quetiapine augmentation of SRIs in treatment refractory obsessive-compulsive disorder: a double-blind, randomised, placebo-controlled study [ISRCTN83050762]

BACKGROUND: Although serotonin reuptake inhibitors are effective in the treatment of OCD, many patients fail to respond to these agents. Growing evidence from open-label and placebo-controlled trials suggests a role for augmentation of SRIs with atypical antipsychotics in OCD. Quetiapine is generally well tolerated and previous open-label data has produced mixed results in OCD and additional controlled data is needed. METHODS: We undertook a double-blind, randomised, parallel-group, flexible-dose, placebo-controlled study of quetiapine augmentation in subjects who had responded inadequately to open-label treatment with an SRI for 12 weeks. Following informed consent and screening, forty-two subjects were randomised to either placebo or quetiapine for six weeks. RESULTS: There was significant improvement from baseline to endpoint on the Yale-Brown Obsessive-Compulsive Scale in both the quetiapine and placebo groups (quetiapine, n = 20, p < 0.0001; placebo, n = 21, p = 0.001) with 40% (n = 8) of quetiapine and 47.6% (n = 10) of placebo treated subjects being classified as responders. Quetiapine did not demonstrate a significant benefit over placebo at the end of the six-week treatment period (p = .636). Similarly quetiapine failed to separate from placebo in the subgroup of subjects (n = 10) with co-morbid tics. Quetiapine was generally well tolerated. CONCLUSIONS: In this study, quetiapine augmentation was no more effective than placebo augmentation of SRIs. A number of limitations in study design make comparisons with previous studies in this area difficult and probably contributed to our negative findings. Future work in this important clinical area should address these limitations