Background Short implants have been proposed as an alternative for the rehabilitation of atrophic edentulous areas. Purpose To evaluate the efficacy of 4‐mm implants vs longer implants in the atrophic posterior mandibles. Materials and Methods Eleven patients with bilateral atrophic mandibles were rehabilitated with two to four 4‐mm implants and 10 or 8‐mm long implants in augmented bone using Guided Bone Regeneration procedure. One side of the mandibles was randomly allocated to vertical augmentation with mixed autogenous bone and allograft. Implants were placed in both sides of the mandible after 6 months, and loaded after another 2 months. Subsequently, implant and prosthesis failures, marginal bone levels changes, and any complication were evaluated after 1‐year follow‐up. Results In this study, one patient dropped out and no failures occurred. However, 4‐mm implants loss of 0.30 ± 0.34 mm peri‐implant marginal bone and long implants loss of 0.47 ± 0.54 mm marginal bone were observed after 1‐year of follow‐up. The difference between the two groups was not statistically significant (difference = −0.16 ± 0.68 mm; P = 0.46). Eight complications occurred in five augmented sites of the patients, and no complication was found to occur in the short implants sites. Conclusions One‐year after loading, 4‐mm implants had similar outcomes as long implants in augmented bone. Therefore, short implants might be a feasible treatment in atrophic mandibles.

Background and Aim: Estrogen affects the metabolism in females. This study aimed to assess the effect of absence of estrogen on orthodontic tooth movement in rats. Materials and Methods: In this animal study, 55 rats were randomly divided into four groups. Group 1 (n=10) had intact ovaries. In group 2 (n=15), ovaries were intact but the rats were subjected to stress due to tooth preparation. In group 3 (n=15), the ovaries were intact but the rats were subjected to stress due to tooth preparation and surgical manipulation. In group 4 (n=15), ovaries were removed and the rats were subjected to stress due to tooth preparation and surgical manipulation. Orthodontic appliances were placed after 14 days in groups 2 to 4. All groups except for group 1 were subjected to mesial movement of maxillary right first molar using NiTi closed coil spring applying 60g load for 21 days. The rats were sacrificed at 21 days and the amount of orthodontic tooth movement was measured using a feeler gauge. Data were analyzed using ANOVA. Results: The mean orthodontic tooth movement was 1.18±0.2 mm in group 4, which was significantly greater than that in group 3 (0.47±0.18 mm) and group 2 (0.22±0.07 mm) (P<0.001). Conclusion: Absence of estrogen can significantly accelerate orthodontic tooth movement in rats.

Objectives: We aimed to evaluate the knowledge and attitude of Iranian dentists towards cone-beam computed tomography (CBCT). Materials and Methods: A 20-item questionnaire was distributed among 410 Iranian dentistry graduates attending the 56th Congress of Iranian Dental Association held in Tehran, Iran. The questionnaire included items on demographic characteristics, namely full name, age, gender, work experience, type of current activity (individual or group), and the highest educational level. In addition, the questionnaire contained items on the knowledge and attitude of dentists. The obtained data were analyzed using statistical tests. Results: In this study, 49.3% and 22.4% of the subjects were male and female, respectively, 47.1% of whom used CBCT, while 49.8% did not. In detail, 72.2% of the dentists used the technique to evaluate the location of implants, whereas 19.7%, 3.2%, and 2.7% of the subjects applied it to localize the inferior alveolar nerve (IAN), evaluate the location of implants and localize the IAN, and perform cephalometric analysis, respectively. The main causes of lack of prescription of CBCT entailed high cost (80%), high rate of patient absorbed dose (27.6%), insufficient number of CBCT centers (46.3%), and the long duration of the process (15.6%). Conclusion: CBCT is an advantageous imaging technique in dentistry. Considering the increased application of CBCT in dentistry, attending workshops could help train dentists to use the technique.

Approximately 45% of patients had at least 1 septum, and this finding emphasizes the need for the assessment of the maxillary sinuses to prevent complications.

No significant difference was seen between the two techniques. The specificity of DDR was slightly better than CR, and their accuracy and sensitivity showed small differences.

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The main objective in root canal preparation is to develop an enlarged and shaped taper from apical to coronal, maintaining the original canal shape. The aim of this study is analysis of root canals dentin removal shaped by MTwo (Group M) and K3 (Group K) rotary fi les using spiral-computed tomography. A total of 40 mesiobuccal root canals of mesial roots with curvatures ranging 20-35 degree, and working length ranging 15-17 mm included the study. The initial images were reconstructed and cross-sections corresponding to distance 2, 4.5 and 7mm from the anatomic apex. Group M was prepared with Mtwo fi les with master apical fi le size 40 (single length technique) and group K was prepared with K3 fi les (VT technique, %4), with master apical fi le size 40. Post instrument images was recorded as same as the initial ones. Dentinal thickness measured in buccal, mesial, lingual and distal sections of each root canal. Statistical analysis was performed with one sample test Kolmogorov-Smirnov and T-test for comparing samples between groups. The mean total root dentine removal between group M (0.17+-0.04) and group K (0.20+_0.07) was statistically different (P<0.001). Group K showed 15% more dentin removal compared group M. Recording to our fi ndings K3 had showed more dentin removal than Mtwo especially in apical and coronal third of curved root canals, so Mtwo acted better than K3.

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