Aneurysmal bone cyst of the mandible: case presentation and review of the literature

The aneurysmatic osseus cyst is a very infrequent bone lesion which in some occasions can be found at the craniofacial skeleton. Among all the cystic lesions that can be found at the mandible or the maxilla it is very rare. On the other side it is at the same time very interesting in terms of its differential diagnose with other types of maxillary bone lesions We present the case of a Caucasian male with an aneurysmatic cyst located at the right angle of the mandible and a review of the literature concerning the case. We have focused on the differential diagnose, mainly with the malignancies that can be found at this location. We also comment the therapeutic options classically described for these kind of pathologies. In our patient, the surgical excision allowed a complete removal of the lesion and a posterior bone healing which made possible a implant-supported rehabilitation of the edentulous segment.     

Effects of a nutritional supplement on periodontal status

Among the recommendations for the maintenance of gingival and periodontal health, few have focused on the value of nutritional supplements. The purpose of this study was to compare the effect of certain nutritional and plant-derived nutraceuticals and a placebo tablet in the reduction of gingivitis, bleeding, probing depths, and attachment levels in a 60-day two-cell, randomized, parallel clinical trial for patients with Type II periodontal disease. The vitamin therapy was introduced as an adjunct to patient homecare to determine if there was a quantifiable improvement to soft-tissue health and periodontal damage. Sixty-three patients were randomly divided into two groups of 32 and 31 subjects and given either a vitamin tablet containing seven active ingredients (experimental treatment) or a placebo tablet. The clinical parameters assessed were the gingival index (GI), bleeding index (BI), periodontal pocket depth (PD), and attachment levels (AL), and were recorded at baseline and 60 days. Patients took the assigned tablet at breakfast and at dinner after brushing their teeth twice daily. After 60 days, the data showed a clinical reduction in the GI, BI, and PD for the experimental group (P < .0001). There were no significant changes for AL with either the experimental or the placebo group. When the data were further analyzed for pocket depths of > or = 4 mm in patients receiving the experimental treatment, there were clinically significant improvements in the GI and PD from baseline to 60 days (P < .0001), but no significant differences in the BI and AL. There were no statistical differences in any of the indices when the data were compared between men and women. The results of the present study suggest that a multi-vitamin nutritional supplement might be a beneficial adjunct to the required established periodontal treatment.     

A review of the clinical management of mobile teeth

The clinical management of mobile teeth can be a perplexing problem, especially if the underlying causes for that mobility have not been properly diagnosed. In some cases, mobile teeth are retained because patients decline multidisciplinary treatment that might otherwise include strategic extractions. This article discusses the relationship between occlusion and tooth mobility with an emphasis on identifying differences between increased mobility and increasing mobility. The indications, contraindications, and basic principles of tooth splinting are also reviewed. Provisional and definitive splints are defined and described with their respective occlusal considerations. Some mobile teeth can be treated through occlusal equilibration alone (primary occlusal trauma). Whereas mobile teeth with a compromised periodontium can be stabilized with the aid of provisional and/or definitive splinting (secondary occlusal trauma). It is important to consider splint therapy, because it may not only improve the prognosis of teeth, but may actually enhance the stability of the final prosthodontic treatment. The ultimate goal of successful management of mobile teeth is to restore function and comfort by establishing a stable occlusion that promotes tooth retention and the maintenance of periodontal health.     

Effects of phosphoric acid on bovine enamel bleached with carbamide peroxide

The aim of this study was to measure the demineralization capacity of 37% phosphoric acid on bovine enamel at different time-points after bleaching with 30% carbamide peroxide. Five, 4 × 4-mm sections were obtained from the enamel of 10 bovine incisors. After applying 30% carbamide peroxide (Vivastyle) for 90 min, specimens were stored in artificial saliva for 0, 24, 72 h, or 7 d and then immersed in 37% phosphoric solution. At 15, 30, 60, 90, and 120 s, 5-ml aliquots were extracted. A control group of specimens was not bleached. Ca²⁺ concentrations were measured by atomic absorption spectrophotometry. A larger amount of Ca²⁺ was extracted from enamel by phosphoric acid after the application of 30% carbamide peroxide. Twenty-four hours after bleaching, significantly more Ca²⁺ was extracted from bleached than from control specimens at all time-points, and this greater susceptibility to the action of the acid persisted for at least 1 wk after bleaching.     

A study of the septa in the maxillary sinuses and the subantral alveolar processes in 30 patients

The objective of this paper is to study the incidence of septa in the maxillary sinus and measure the height of the underlying alveolar process using panoramic radiography and computerized tomography (CT scans). Thirty patients who were going to be treated with dental implants were submitted to panoramic radiographs and CT scans. Sixty maxillary sinuses were analysed and divided into 2 groups: group 1 (totally edentulous) and group 2 (partially edentulous). The sinuses were divided into 3 regions (anterior, middle, and posterior), the septa were analysed, and the heights of the alveolar processes were calculated in these 3 areas. Of the 30 patients, 36.5% had maxillary sinuses, and 25% of these sinuses had septa, and 11.8% of the panoramic radiographs were false-negatives. In the panoramic radiographs of 10 patients, 3 had bilateral septa, 5 had a septum in only one sinus, and 2 patients had 2 unilateral septa. In the CT scans of 11 patients, 4 patients had a bilateral septa, 5 had a septum in only 1 sinus, and 2 patients had 2 unilateral septa. Therefore, 2 more septa were observed in the CT scans. In the study of the height of the subantral alveolar process, the least amount of difference between both techniques occurred in the middle region of the sinus. The CT scan is more reliable than the panoramic radiograph in diagnosing maxillary septa because of its greater accuracy. In the panoramic radiograph, the middle portion of the alveolar process in the posterior subantral segment was the least distorted of the three portions measured.     

Mechanical behavior of ProTaper universal F2 finishing file under various curvature conditions: a finite element analysis study

Introduction

The purpose of this study was to visualize the stresses and strain distribution patterns in ProTaper Universal F2 files (Dentsply Maillefer, Ballaigues, Switzerland) and to establish the stress- and strain-curvature relationship for this instrument under various conditions by using a dynamic, three-dimensional finite-element model.

Methods

An accurate geometric model of a ProTaper Universal F2 instrument was created. Two short, straight tubes were also modeled to represent the parts of root canal apical and coronal to the curvature. Then, the file was constrained to a curve of varying degree, curve length, and position. The maximum von Mises stress and strain on the tension side of the instrument was measured at 5-degree intervals in a numerical simulation package (LS-DYNA; Livermore Software Technology, Livermore, CA).

Results

The mechanical performance of the ProTaper F2 file under various conditions was simulated. A long curvature length produced lower values of stress and strain under the same angle of curvature. An increase in the curvature angle generally induces higher stress and strain. For the same degree and curve length, the stress and strain increased if the curved portion was situated further up the shaft of the instrument (ie, with a larger diameter).

Conclusions

The dynamic, numerical model may be used to evaluate and compare the effect of various root canal curvatures on the behavior of different designs of root canal instrument. The magnitude of stress and strain imposed on the instrument is influenced by the abruptness and degree of curvature as well as the location of the curved portion.     

Peripheral T-cell subsets in patients with reticular and atrophic-erosive oral lichen planus

OBJECTIVE: Oral lichen planus (OLP) presents with various clinical forms that can be classified into 2 major types: reticular OLP and atrophic-erosive OLP. Our objective was to investigate immunologic differences between these 2 types. STUDY DESIGN: We investigated possible immunologic differences between 26 patients with reticular OLP and 26 patients with atrophic-erosive OLP. RESULTS: No differences were detected in serum Ig levels or complement levels. However, the mean proportions of CD4+CD45RO+ and DR+ lymphocytes were significantly higher in patients with atrophic-erosive OLP than in patients with reticular OLP, whereas the mean proportion of CD8+CD45RA+ lymphocytes was significantly lower in patients with atrophic-erosive OLP. CONCLUSION: These findings suggest that the 2 clinical types of OLP might have different immunopathogenic mechanisms.