Introduction The objective of the present study was to evaluate the effect of implant-supported partial overdenture design in restoring mandibular long class IV Kennedy's classification on the supporting structure, both clinically and radiographically. Materials and methods Ten partially edentulous patients with lower six anterior teeth missing were selected. Their ages ranged from 40 to 50 years. Each patient received two dental implants placed in the lower edentulous span at the canine area bilaterally. Ball-and-socket attachment (polycarbonate housing with rubber O-ring) was used between the implant and the overlay removable partial denture for retention. Periodic evaluation was carried out for every patient before denture insertion and then after 3, 6, and 9 months. As regards the clinical evaluation, the probing depth, gingival level, and attachment level around the implants were recorded. The radiographic evaluation included the use of specially developed software for measuring the alveolar bone density in gray scales and the bone height in pixels for the implants and the residual alveolar ridges. Results All implants were highly successfully osseointegrated at the end of this study. There was a statistically nonsignificant increase in the clinical parameters (probing depth, gingival level, and attachment level) around the dental implants throughout the 9-month follow-up period after denture insertion. Radiographically, there was a nonsignificant increase in bone loss, but a significant increase in bone density around the dental implants and the alveolar ridge throughout the follow-up period. Conclusion From the previous results, it was found that the concept of immediate loaded dental implant was efficient to be used successfully in the mandibular long Kennedy class IV to retain the partial overdenture.

Introduction Noncarious cervical lesions are a very common occurrence in clinics. They also represent one of the less durable types of restorations and have a high index of loss of retention, marginal excess, and secondary caries. Aim of the study Considering the aspects related to abfraction and the materials frequently used in its restoration, we conducted an in-vitro study to investigate the relationship between occlusal loading and the microleakage of cervical wedge-shaped esthetic restorations. Materials and methods Sixty wedge-shaped cavities in extracted upper premolars were divided into three groups (n=20). Group I was restored with GrandioFlow, group II was restored with Compoglass F, and group III was restored with PhotacFil Quick Aplicap. Half of the specimens from each group were subjected to occlusal loading (2 kg for 5 min at a rate of 120 cycles/min for 600 cycles) on the buccal cusp, and the other half were used as controls without loading. All teeth were then thermocycled. The teeth were water-sealed and immersed in methylene blue solution for 3 h. The samples were cut buccolingually and the leakage scores were assessed for all groups at the occlusal and cervical walls using a steriomicroscope. Results There was no significant difference between loaded and unloaded tested restorations neither at the occlusal nor at the cervical margin. Conclusion Occlusal loading did not have an effect on the margins of cervical abfraction-like lesions.

Objectives The purpose of this study was to evaluate the dental, skeletal, and soft-tissue change in crowding cases treated with nonextraction approach using the Damon system. Materials and methods The sample included 20 patients, with an average age of 17.8 ± 3.7 years, selected on the basis of pretreatment class I skeletal and molar relationships with an acceptable soft tissue facial profile, and a moderate crowding range between 4.0 and 9.0 mm for the maxilla and 2.0 and 6.0 mm for the mandible. None of them had received any orthodontic treatment before, or had extraction or any congenital anomalies such as supernumerary teeth. Results The evaluation of the study was performed by detecting the dental, skeletal, and soft tissue changes between pretreatment and post-treatment study models and lateral cephalometric radiographs. The paired t-test was used for statistical analysis. The treatment required 20.7 ± 2.2 months to be finished, with an average of 13.8 ± 1.5 appointments. Conclusion The results of this study revealed that the correction of crowding was achieved through expansion of the dental arches and mandibular incisors proclination.

Purpose The aim of the present study was to analyze retrospectively the age and sex distribution, etiology, and location of mandibular and midface fractures in a sample of patients from the Oral and Maxillofacial Surgery Department, Alexandria University, Egypt. Patients and methods The data for this study were obtained from the medical records of 177 cases treated at the Oral and Maxillofacial Surgery Department, Alexandria University, from April 2010 to August 2011. Results The total number of patients with maxillofacial trauma presenting to the Oral and Maxillofacial Surgery Department, during the period from April 2010 to August 2011 was 177 patients. The male population was more frequently affected compared with the female population, males were more frequently affected than females, where males accounted for 82% (145 patients) and females accounted for 18% (32 patients) of the study population with a ratio of 4.5:1. The ages of the patients in the study population ranged from 1.5 to 75 years, with a mean of 25.56 ΁ 14.04 years. Road traffic accident (RTA) was the most common cause of trauma, accounting for 77.97% (138) of cases. A total of 103 cases had isolated mandibular fractures, 54 cases had midface fractures only, and 20 patients had mandibular fractures associated with midface fractures. The most common site in mandibular fractures was the parasymphysis (40.64%; 63 fractures), and zygomaticomaxillary complex fractures were the most common, accounting for 70.13% (54 fractures) of midface fractures. Most of the fractures were treated by means of open reduction and internal fixation using plates (144 cases; 81.36%), whereas the remaining 33 (18.64%) cases were treated conservatively by means of closed reduction. The duration of hospital stay ranged from 0 to 26 days, with an average of 7.34 ΁ 4.64 days. Conclusion RTAs are the main etiological factor in maxillofacial injuries occurring in Alexandria, with men between 21 and 45 years of age being affected predominantly. Preventive strategies remain the best way to reduce the sequelae of RTAs.

Objectives The purpose of this study was to evaluate the relationship between skull thickness and different skeletal patterns in both sexes. Materials and methods A total of 120 pretreatment lateral cephalometric radiographs of adult patients seeking orthodontic treatment at the orthodontic clinic in the Faculty of Dentistry, University of Tanta, were evaluated. The patients' ages ranged between 18 and 25 years. All radiographs had been classified into two categories according to the anteroposterior and vertical relationships as follows: normodivergent facial pattern with an FH-MP angle between 22 and 28° and a normal sagittal pattern with an ANB angle between 2 and 4°. The thickness of the frontal, parietal, and occipital bones was measured on lateral radiographs of patients with skeletal class II and class III, both high-angle and low-angle cases, and compared with the control group. Results Female patients with skeletal class II malocclusion had a significantly thicker frontal bone and thinner occipital bones compared with male patients. Conclusion The frontal bone and occipital bones are important key bones for understanding the calvarial phenotype and sexual dimorphism in different skeletal patterns.

Purpose The objective of this in vitro study was to evaluate the retentive strength of 3 clasp materials Acetal resin (Ac), Cobalt- Chrome (Co-Cr) alloy and Nickel-Chrome (Ni-Cr) alloy before and after cyclic loading. Materials and methods A total of 72 clasps (24 clasps for each material) were fabricated on standardized metallic molar models. The clasps of each material were divided into 3 groups 8 clasps each according to degree of undercuts (0.01, 0.02 & 0.03 inch). Each clasp assembly was subjected to 730, 1460, 2190 and 2920 cycles of insertion and removal of a removable partial denture. Retentive strength was measured before and after each cyclic period. Retentive strength values were analyzed using ANOVA and Fisher's PLSD multiple comparison test at the 0.05 level of significance. Results Ac clasps had significantly lower retentive strength than Co-Cr and Ni-Cr clasps. Clasps with 0.01 inch undercut showed significantly less retention than clasps with 0.02 inch undercut and the latter showed significantly less retention than clasps with 0.03 inch undercut. All clasps exhibited continuous significant decrease in retentive strength from the first period of cyclic loading till the end of the cycling except for Acetal resin at 0.01 inch undercut which show no significant difference after 730 cyclic loading. Conclusion There was significant decrease in retentive strength of the 3 clasp materials.

Purpose Laser welding is an important recent method to join prosthetic metal frameworks. However, no previous study investigated the effect of laser parameters on silver–palladium alloys. Therefore, the purpose of this study was to investigate the effect of laser voltage on the welding efficiency of laser-welded silver and cobalt–chromium alloys. Materials and methods Cast plates of silver (Ag) and cobalt–chromium (Co) alloys were prepared (0.5×3.0×10 mm) and polished (600 grit, SiC paper). After they were butted against each other (Ag/Co), laser-welded specimens were prepared using Nd:YAG laser at a pulse duration of 10 ms, spot diameter of 1 mm, and voltages of 200, 220, 240, and 260 V. The weld pattern comprised five laser spots bilaterally. Nonwelded cast specimens were also prepared of both alloys and served as controls. Fracture load and percent elongation were measured using a universal testing machine at a crosshead speed of 1.0 mm/min. The data (n = 5) were statistically analyzed using the analysis of variance/Tukey's HSD post-hoc test (α = 0.05). Results Increase in laser voltage led to increased fracture load and percent elongation. There was no statistically significant difference in fracture load value between Ag control (993 N) and Ag/Co welded at 260 V (950 N). Moreover, there was no statistically significant difference in percent elongation between Co control (2.3%) and Ag/Co welded at 260 V (2%). Conclusion Under laser parameters used in this study, the highest obtained fracture load of laser-welded Ag/Co at 260 V was statistically equivalent to nonwelded Ag. Moreover, the highest obtained percent elongation of laser-welded Ag/Co at 260 V was statistically equivalent to that of nonwelded Co.

Purpose The aim of the present study was to evaluate enamel remineralization with NovaMin (amorphous sodium–calcium–phosphosilicate paste) and low-level laser (LLL) for white spot lesions after orthodontic therapy. Materials and methods A total of 20 premolars divided into four groups were submitted to three phases: (i) placement fixed orthodontic appliances; (ii) demineralizing solution; and (iii) remineralization for groups (group A, control; group B, NUPRO Sensodyne with NovaMin; group C, LLL; and group D, NovaMin and LLL). In each stage, elemental analysis (calcium, phosphorus, and sodium) was measured under a scanning electron microscope; the data were tested to find significant differences between mineral changes during phases by using the Bonferroni test and Tukey's test between groups. Results Calcium and sodium decreased and phosphorus ions increased in all groups at stage 2. In stage 3, all minerals increased for all the tested groups, recording greater values in group B. Calcium showed a statistically significant difference on comparing stage 1 with stage 2 (P = 0.025) and stage 2 with stage 3 (P = 0.019). On the other hand, using the Bonferroni analysis, phosphorous recorded a significant difference on comparing stage 1 with stage 3 (P = 0.013). Applying Tukey's test, a statistical significant difference between groups A and B was recorded as regards the calcium level (P = 0.004) and the phosphorus level (P = 0.003), which also showed a significant difference between group A and group C (P = 0.052). As regards the sodium distribution, no significant differences were found. Conclusion According to the results obtained in the current study, using NUPRO Sensodyne with NovaMin than using LLL proved to be the better treatment for white spot lesions, leading ion incorporation and providing an effective alternative for dental demineralization.