A New Experimental Technique for Complete Extraction of Mandibular First Molar Teeth in Rats.

Intact extraction of the mandibular first molar tooth is an interesting model for studies of alveolar bone healing. The aim of this study was to describe a new experimental technique for extraction of rat mandibular first molar teeth with crown and all 4 roots intact using controlled forces applied to the teeth. One hundred and twenty female Sprague-Dawley rats were used from a center for experimental animal research. Animals underwent general anesthesia and were then placed in a special dental unit (designed by Moghadam) for the extraction of rat teeth. After syndesmotomy, luxation of the tooth began with a tipping movement in the buccal direction with a very low range of motion for 1 s. A tipping movement in the lingual direction was then used to continue luxation. After a maximum of 10 repetitions, the tooth was left alone for 30 s. After 3-4 stages of this cycle, the tooth loosened. To complete the luxation, the same forces were applied in the buccal and lingual directions with larger amplitude for 3 s. After this step, the tooth was loose enough to be easily extracted. The alveolus was then sutured closed. The results showed no hemorrhage or fracture of crowns and mesial or distal roots, and only 8% of the buccal and lingual roots fractured. The technique designed and used in this study was shown to be an effective model for complete molar tooth extraction in the rat. This technique could also be used in the treatment of other rodents.

Evaluation effect of color in dental office and dentist's uniform while using two different distraction techniques on injection anxiety of 6-9 years' old children referring to Hamedan Dental School: Randomized clinical trial.

BACKGROUND: The management of children's anxiety in dental offices is still a challenge for the treatment team. The most important factors which affect children's dental anxiety are the clinician-related factors and the physical factors of the dental operatory. Color is an environmental factor whose relationship with the perceptive and emotional factors of children has been reported. On the other hand, distraction is essential factors in a treatment environment that can be used to manage children's anxiety. MATERIALS AND METHODS: In this randomized clinical trial study, from 132 6 to 9 years of age children, 52.3% were male, and 47.7% were female, with a mean age of 7.45 ± 1.1 years. The children's anxiety levels were determined using the Venham Picture Test and pulse oximetry before and after the administration of local anesthesia. The children were randomly assigned to two groups (n = 66): Group 1, music, and Group 2, animated cartoons. The data were analyzed with SPSS 25, using descriptive statistics and the statistical tests consisting of one-way analysis of variance (ANOVA), t-test, and repeated-measures ANOVA, followed by Tukey honestly significant difference tests. Statistical significance was set at P < 0.05. RESULTS: The anxiety levels were the lowest in the blue and pink environments and the highest in the black and red. Anxiety levels between different colors in terms of physiologic markers and the questionnaire in each distraction technique at different intervals was significantly different. CONCLUSION: The use of blue, pink, green, and yellow for dentists' attire, and the interior design of the dental operatory decreased the child patients' anxiety.