[Symmetry of cervical multifidus muscle in females with chronic non-specific neck pain and healthy by ultrasonography]

Multifidus muscle is one of the short and deep posterior Paraspinal muscles, which gives stability to the spine during various activities. Studies have shown that in people with neck pain, weakness and atrophy of neck muscles are major factors in the incidence of neck pain. Measurement of muscle's dimensions by ultrasonography provides an opportunity to be able to objectively assess muscle atrophy or hypertrophy. This study aimed to assess symmetry of cervical multifidus muscle size in females with chronic non-specific neck pain and healthy by ultrasonography apparatus. Twenty five women with unilateral chronic nonspecific neck pain and 25 healthy women were participated in this study. All subjects were employed and more than 4 hours working with computers or paying office in a day. Imaging of the cervical multifidus muscles were done bilaterally in the level of the fourth vertebra. Anterior-Posterior Dimension [APD], Lateral Dimension[LD], Cross-Sectional Area [multiplied of two diameters[APD and LD]] and the Shape ratio [Lateral diameter divided by the Anterior-Posterior diameter[LD/APD]] of the muscle were measured and recorded. Multifidus muscle size in patients group was smaller than the healthy group. In patients group, size of multifidus muscle in the painful side was smaller than the opposite side. Asymmetry of muscle size between the two sides, in the patient group was higher than the control group [P < 0.05]. The ratio of smaller size to the larger size of the muscle, in the healthy group was higher than the ratio in the patient group [P < 0.05]. In patients group, asymmetry of the muscle size between two sides, also smaller size of the muscle in the painful side, showed that muscle atrophy has happened in the involved side

[Effect of two mouth-rinses on the surface hardness of two types of direct and indirect composites]

Mouth-rinses may soften composite restorations even when the composite is light cured or heat treated. The use of certain mouth-rinses may have less adverse effect on composite restorations. The aim of this study was to evaluate the effect of alcoholic and non alcoholic mouth washes on the surface hardness of two types of direct [Z100] and indirect [Gradia] composites. Sixty disc shape samples of Gradia [n=30] and Z100 [n=30] composite were prepared and cured for 40 seconds by halogen light cure unit. Gradia composite specimens were post cured with labolight machine for 5 minutes and then were stored in distilled water for one week at 37c°. The samples were exposed to 3 different solutions of alcoholic, non-alcoholic mouth-rinses, and water for 24 hours at room tempreture. Surface hardness [VHN] was measured and data were analyzed by using One-way ANOVA and Scheffe tests [alpha <0.05]. Statistical analysis revealed that, indirect composites which were kept in alcoholic, and non alcoholic solution showed less hardness than control group [water] [p0.0001]. Direct composite specimens which were kept in alcoholic mouthwash had less hardness than control group [p0.003]. Surface hardness of indirect composite specimens kept in alcoholic and nonalcoholic mouth-rinses was significantly higher than direct composites in these solutions [p0.002 and p=0.008, respectively]. Alcoholic and non alcoholic mouth-rinses caused reduction of surface hardness of direct and indirect composites and it seems that the effect of mouth-rinse on surface hardness of these composites is material dependent. Indirect composite showed to be harder than direct composite in all solutions