Objectives: The aim of this study was to compare and evaluate the guidelines proposed by Counihan et al 2013 and the KPG index method for assessment of maxillary impacted canine position using CBCT images from a radiographic point of view. Subjects & methods: Thirty-six CBCT scans of 36 patients (6 males and 30 females), with a total number of 45 impacted maxillary canines, were recruited from the database of the Oral and Maxillofacial Radiology Department, Faculty of Dentistry, Cairo University. KPG index, for each impacted canine, was calculated by giving both its cusp and root tips a score on a 0-5 scale along the x, y, and z planes. The summation of these six scores would predict the treatment difficulty, classified as easy (0-9), moderate (10-14), difficult (15-19), and extremely difficult (20 and above). Moreover, Counihan et al 2013 guidelines were applied on each studied impacted tooth in which the tooth position in four categories was considered: overlap with adjacent incisor, vertical height, angulation to midline and position of root apex. For each category, either good, average or poor prognostic outcome was selected. Data were collected and statistically analyzed. Results Upon comparing both studied methods of radiographic assessment of impacted maxillary canines, a statistically significant difference was found: KPG index categorized more cases (9 cases) as easy (20%) while Counihan et al guidelines categorized only 2 cases (4.4%) as having good prognosis. Similarly, KPG index categorized more cases (15 cases) as moderate (33.3%) while Counihan et al guidelines categorized 13 cases (28.9%) as having average prognosis. On the other hand, Counihan et al guidelines categorized more cases (30 cases) as poor prognosis (66.7%) while KPG index categorized only 21 cases (46.7%) as being difficult. Nonetheless, on comparing the treatment difficulty and prognosis of impacted maxillary canines found on the right and left sides, unilaterally or bilaterally, in males and females, a non-statistically significant difference was found using both methods of radiographic assessment. Conclusion From a radiographic point of view, the KPG index, with some minute modifications, has demonstrated to be an effective and competent method for classification of maxillary impacted canine's treatment difficulty in accordance to their position, as compared to the guidelines proposed by Counihan et al at 2013.

This is an open-access article distributed under the terms of a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Public License, which permits unrestricted use, adaptation, distribution and reproduction in any medium, non-commercially, provided the new creations are licensed under identical terms as the original work and the original work is properly cited. ORIGINAL PAPER Periodontal clinico-morphological changes in patients wearing old nickel-chromium and copper alloys bridges LUMINIŢA DĂGUCI 1) , CONSTANTIN DĂGUCI 2) , CRISTIANA IULIA DUMITRESCU 3) , CĂTĂLINA FARCAŞIU 4) , DANIELA IOANA TĂRLUNGEANU 5) , MARILENA BĂTĂIOSU 6) , MAGDALENA NATALIA DINA 7) , CLAUDIU MĂRGĂRITESCU 8) , MIHAELA JANA ŢUCULINĂ 9) , OANA-CELLA ANDREI 5)

The aim of this study was to compare fracture resistance of teeth presenting medium-sized mesial-occlusal-distal (MOD) cavities using different base materials. Thirty-six extracted molars were immersed for 48 h in saline solution (0.1% thymol at 4 °C) and divided into six groups. In group A, the molars were untouched, and in group B, cavities were prepared, but not filled. In group C, we used zinc polycarboxylate cement, in group D—conventional glass ionomer cement, in group E—resin modified glass ionomer cement, and in group F—flow composite. Fracture resistance was tested using a universal loading machine (Lloyd Instruments) with a maximum force of 5 kN and a crosshead speed of 1.0 mm/min; we used NEXYGEN Data Analysis Software and ANOVA Method (p < 0.05). The smallest load that determined the sample failure was 2780 N for Group A, 865 N for Group B, 1210 N for Group C, 1340 N for Group D, 1630 N for Group E and 1742 N for Group F. The highest loads were 3050 N (A), 1040 N (B), 1430 N (C), 1500 N (D), 1790 N (E), and 3320 N (F), the mean values being 2902 ± 114 N (A), 972 ± 65 N (B), 1339 ± 84 N (C), 1415 ± 67 N (D), 1712 ± 62 N (E), and 2334 ± 662 N (F). A p = 0.000195 shows a statistically significant difference between groups C, D, E and F. For medium sized mesial-occlusal-distal (MOD) cavities, the best base material regarding fracture resistance was flow composite, followed by glass ionomer modified with resin, conventional glass ionomer cement and zinc polycarboxylate cement. It can be concluded that light-cured base materials are a better option for the analyzed use case, one of the possible reasons being their compatibility with the final restoration material, also light-cured.

Supernumerary teeth are dental units that appear in addition to the regular number of teeth. Their most frequent location is the anterior maxilla, especially on the maxillary midline, being called mesiodens, but also paramedian or in the position of a lateral incisor. On the other hand, the permanent canine is one of the most stable teeth regarding the number, with very few cases reported about hypo-or hyperdontia. This article reviews the few data found in the literature about the supernumerary permanent maxillary canine and also presents the case of an 8-year-old female patient with a supplemental permanent canine in the upper left maxilla. The patient was non-syndromic and did not present any other supernumerary teeth in the permanent dentition; she had only one in the temporary dentition. Using cone-beam computed tomography (CBCT) of the region, we were able to evaluate the position, structure, and shape of the supplemental canine and also to establish a treatment plan. The aim of this paper was to present this extremely rare case of a non-syndromic Romanian adult female patient with a unilateral supplemental permanent maxillary canine, and to include a literature review of the few reported such cases.

In this paper are highlighted the stresses that appear in the peri-implantation area through the forces induced by the masticatory process. The analysis consists of computer modeling of the dental implant and simulation of the load with a distributed force. It is considered a variable direction loading related to the axial insertion of the dental implant, thus simulating an important masticatory process. This type of load reveals stresses developed in the periimplantary bone area, the risk areas where the stresses can cause the appearance of hard tissue damage near the implant and its failure. Increases in stresses up to 159% in the ruminant type of chewing compared with the cutter type are highlighted. An aggravating factor that can lead to implant failure is bruxism that tangentially stresses the implant leading to the concentration of forces at the abutment-implant junction. Conclusions regarding the decrease of stresses at bone-implant junction with up to 23% by a corresponding increase of the implant diameter by 25% are also issued.