Dental anxiety and fear of needle injection is one of the most common problems encountered by dental practitioners, especially in the pediatric patient. In consequences, it might affect the patient's quality of life. Several methods are suggested to lower the discomfort of local anesthesia injection during dental procedures. Desensitization of injection site is one of the recommended strategies. Among chemical anesthetic topical agents that are effective but might have allergic side effects, using some nonpharmacological and safe techniques might be useful. This study aimed to overview the efficacy of using cooling techniques, mostly by ice or popsicles, warming or pH buffering of drug, and using modern devices to diminish the discomfort of local anesthesia injection during dental procedures.

The purpose of this study was to evaluate the effects of aminoguanidine (AG) as a selective inhibitor of inducible nitric oxide synthase (iNOS) on the degree of inflammatory response in periapical lesions in the canine teeth of cats. Root canals from 52 cat canine teeth were exposed to the oral cavity and sealed after 7 days. One day before pulp exposure, cats were administered either AG (experimental group) or normal saline (control group), which was continued on a daily basis until the day of sacrifice. Animals were sacrificed at 28 days after pulp exposure. Inflammatory response in the periapical zones was analyzed histologically. The degree of periapical inflammation in the AG group was significantly lower than that in the control group (P < 0.05). Selective iNOS inhibitors such as AG thus reduce the intensity of inflammatory responses in periapical lesions.

Objective:The aim of this study was to compare the substantivity of chlorhexidine (CHX) and doxycycline bond to the dentin in diffusion disk method.Methods:A total of 92 dentin disks were prepared from Bovine's teeth root. After removing cementum and standardizing disks in weight and outer diameter, they were irrigated with sodium hypochlorite 2.5%, ethylenediaminetetraacetic acid 17% and sterile saline and sterilled in autoclave. Then, the first group (n = 36) were irrigated with chlrohexine 2% and the second group (n = 36) with doxycycline 100 mg/mL, each for a period of 10 min. The third group (n = 20) was considered as the control group. Samples were divided into four subgroups, which after 1 day, 3, 6, and 12 weeks were incubated in plates containing Muller Hinton agar broth and Enterococcus faecalis for a period of 48 h at 37°C temperature; then the diameter of the zone of inhibition was measured. The antimicrobial effect of irrigating solutions without binding to the dentin was also studied using the plate well method. One-way and univariate variance tests as well as Post-hoc Tukey were used for data analyses.Findings:The diameter of the zone of inhibition of doxycycline group was significantly more than the CHX group from the beginning to the 3rd week (P < 0.005). After 3rd week, mean diameter in doxycycline group declined as compared with the CHX group up to 12th week (P < 0.005). The difference between means in two groups was not significant in the 3rd week (P = 0.87).Conclusion:The results of this study show that CHX and doxycycline show antibacterial activity for 12 weeks; although after 3rd week, the substantivity of CHX was significantly greater than doxycycline. Both of these irrigants can be used in other pharmacological and medical fields whenever a long-lasting antibacterial action is needed.

Background and objective: Diagnosis of Horizontal Root Fractures (HRF) is based on clinical and radiographic documents. The aim of this study was to compare the diagnostic accuracy of digital Periapical Radiographs (PSP) with different angulations in different locations and Cone Beam Computed Tomography (CBCT) in the detection of HRF in central and lateral maxillary incisors. Materials and Methods: For this experimental study, 60 human central and lateral maxillary incisors were selected and were divided into 4 groups and were numbered. Root fractures were created by using mechanical force in the apical third, middle and cervical part of roots in the groups 1 to 3. The last group was considered as a control group without any fractures. The two fragments from each tooth were relocated with super glue. Then, the radiographic images of all the teeth were taken using digital PSP and CBCT methods. Afterward, two oral and maxillofacial radiologists assessed the images separately. The data were subjected to specificity and sensitivity for each radiographic technique. The kappa statistics were used for assessing the agreement between observers. The Significance level was considered as P<0/05. Results: CBCT method had higher specificity and sensitivity in the detection of HRF compared to PSP. Kappa value for inter-observer agreement in HRF was 0/89 for CBCT and 0/725 for PSP. Conclusion: CBCT outperformed the PSP method in detecting simulated HRF. CBCT should be used as the reliable imaging method for the diagnosis of HRF.