eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2017-06-20 10 2 921 926 10.13005/bpj/1186 15212 article Elham Farokh-Gisour 1 pegah kiani 2 masoud parirokh 3 masoumeh aminizadeh 4 Department of pediatric dentistry, faculty of dentistry, Kerman university of medical sciences, Member of Department of Endodontics, Kerman University of Medical Sciences, Kerman, Iran. Department of Endodontics, Kerman University of Medical Sciences, Kerman, Iran. Department of Endodontics, faculty of dentistry, Kerman university of medical sciences, Member of Kerman Oral and Dental Diseases Research Center, Kerman, Iran. Department of pediatric dentistry, faculty of dentistry, Kerman university of medical sciences, Member of Department of Endodontics, Kerman University of Medical Sciences, Kerman, Iran. The aim of this study was to evaluate the presence or absence and difference of cotton size in gnashing strength of teeth filled with temporarily dressing material «coltosol». In this study, 60 human premolar teeth that had been extracted for orthodontic reasons or periodontal problems are done. Samples by stereomicroscope to leave a review before work were examined. On the teeth, access cavities for (MOD) created and for the removal of dentin tissue, teeth canals were prepared up to number 30 files. A picture was taken teeth before and after access, cavity preparation and teeth were divided randomly into four groups of 15.  The first group without dressing as a control group, the second group has a cotton ball with a bandage covering only orifices (Coltosol) and the third group with a cotton ball with a bandage covering larger pulp chamber and the fourth group without a cotton ball and was just dressing. All samples were stored in room temperature water. The teeth 2500 cycle in the thermocycled were placed and then press each tooth with a Testometric and the failure threshold were recorded and analyzed by ANOVA test was used. The results showed that application of cotton under dressing lead to reduce the strength gauze is compared to lack of cotton (ANOVA, p <0.05).The results showed that application of cotton under dressing led to a reduction in the strength of the dressing material in premolars teeth. Also, by increasing the thickness of cotton, dressing strength reduced. https://biomedpharmajournal.org/vol10no2/a-study-investigating-the-effective-pharmacological-factors-in-the-strength-of-filled-teeth-with-a-medicinal-material/ Pharmacological Study Dentistry Clinics temporary restoration Coltosol Cotton ball Compressive strength