Positional vertigo afterwards maxillary dental implant surgery with bone regeneration

Benign paroxysmal positional vertigo (BPPV) is the most common form of vertigo. It is caused by loose otoconia from the utricle which, in certain positions, displaced the cupula of the posterior semicircular canal. BPPV most often is a result of aging. It also can occur after a blow to the head. Less common causes include a prolonged positioning on the back (supine) during some surgical procedures. Additionally one can include in this ethiopathogenesis the positioning required during the maxillary dental implant surgery with bone regeneration related to a forced head positioning and inner ear trauma induced by dental turbine noise working in the maxillary bone. Two cases of patients who suffered BPPV after undergoing maxillary dental implant with bone regeneration procedures are reported. Diagnosis and treatment are also described.     

Benchmarking of reported search and selection methods of systematic reviews by dental speciality

BACKGROUND: Previous evaluations showed that literature-search and selection methods reported in dental systematic reviews (SR) have improved since 2000. It is not known, however, whether these differences are consistent between the SR of the different dental specialities. METHODS: SR in dentistry published in the English language between 1 January 2000 and 14 June 2006 were located and then categorised by American Dental Association (ADA) recognised specialities. Search and selection methods were evaluated following an adaptation of the Cochrane Handbook for Systematic Reviews. Search and selection methods between dental specialities were compared using Pearson's chi-squared analysis and ranked. RESULTS: There were significant differences between specialities in the following criteria: documentation of search dates (P 0.003); inclusion-exclusion documentation (P 0.017); article selection by two or more reviewers (P 0.001); and inclusion of all languages (P 0.014). Periodontics SR met the most criteria followed by oral and maxillofacial surgery (OMS) and then dental public heath (DPH). Prosthodontics along with the area of oral and maxillofacial radiology (OMR) met the fewest. All dental SR had low compliance with four criteria, only 65.7% searched more than Medline, 50.4% had a search strategy documented with Boolean operators, 51.5% had article selection carried out by two or more reviewers and only 25.7% included all languages. CONCLUSIONS: Some dental specialities are better at reporting search and selection methods than others but all dental SR need some improvement in their reporting.     

Shear bond strength between metal alloy and a ceramic system, submitted to different thermocycling immersion times

The aim of this study was to evaluate the shear bond strength of Co-Cr and Ni-Cr metal alloys and a specific ceramic, submitted to different thermocycling immersion times. Sixty metal-ceramic specimens were confectioned and standardized in cylindricalformat. Three thermocycling conditions were evaluated: without thermocycling, 3,000 cycles (5 degrees C/55 degrees C+/-1) with 30s of immersion time and 3,000 cycles (5 degrees C/55 degrees C+/-1) with 60s. The shear bond strength was performed in a universal testing machine, using a special device to concentrate the tension at the metal/ceramic interface during the test. The load was applied until fracture of the specimens. The data was statistically analyzed by ANOVA (two-way) and Tukey (p<0.05) test. The results didn't show significant statistic differences between the metal-porcelain combinations. Nevertheless, both metal-ceramic systems submitted to 60s of immersion time showed lower values compared to specimens without thermocycling. It was concluded that the thermocycling immersion time of 1 minute affect the shear bond strength values for the Ni-Cr/porcelain and Cr-Co/porcelain systems.     

Use of radiographs for periodontal diagnosis in private practice

The aim of the present study was to determine the percentage of dentists who use radiographic examination on the initial appointment, and establish the relation between the use of periodontal probe and graduation year. Dentists were interviewed in their private offices in three cities in Rio Grande do Sul. They were asked about the routine use of radiographic examination and, if applicable, what technique was applied and what clinical instrument was used at the first appointment. Opened and closed questions were included in the interview and for some of them more than one answer was possible. A significant number of dentists (62.9%) reported some kind of radiographic examination at the initial appointment. Among the radiographic techniques, the periapical was the most cited (74.3%), followed by the panoramic (36.2%) and bite-wing (32.9%) techniques. There was an association between the use of periodontal probe and the use of radiographic examination at the initial appointment. Dentists who used periodontal probe used radiographic examination more frequently (p=0.010). More recently graduated dentists (1991-2005) used radiographic examination more than the others (p=0.022). In conclusion, a large number of dentists reported the use of radiographic examination at the initial appointment. There was an association between the use of this examination technique and the use of the periodontal probe; recently graduated dentists used radiographic examinations more frequently than the others.     

Composite depth of cure obtained with QTH and LED units assessed by microhardness and micro-Raman spectroscopy

This study analyzed the depth of cure of a composite assessed by microhardness and the degree of conversion as a function of the light cure unit (LCU) used. Two light cure units, one LED (Ultraled-Dabi Atlante) and one quartz-tungsten-halogen (QTH, Optilux 401-Demetron) unit were used to cure 4.0 x 4.0 mm and 5.0 mm deep composite specimens (Filtek Z250, 3M ESPE). After 24 hours storage at 37 degrees C, Knoop microhardness and degree of conversion were measured on the irradiated surface and at each millimeter of the sample's depth. The degree of conversion was determined by using micro-Raman spectroscopy. The specimens cured with the QTH unit presented uniform decay in microhardness up to 4 mm in depth. Beyond 4 mm, the drop was abrupt. With LED photoactivation, uniform decay was observed only up to 2 mm. At higher depths, the decay in microhardness increased rapidly, especially beyond 3 mm. Depth of cure assessed by micro-Raman revealed that the degree of conversion behaved similarly to microhardness for both LCUs. A strong linear regression between microhardness and the degree of conversion, including both LCUs, was established with R2 = 0.980.     

Prevalence of human papillomavirus in squamous cell carcinoma of the tongue

Oncogenic human papillomaviruses (HPVs) are important agents in the genesis of gynecological cancer, and have also been implied in the genesis of oral cancer. With the purpose of evaluating the relationship between HPV and squamous cell carcinoma (SCC) of the tongue, a case-control study was performed. Fifty white male patients who were smokers and had the histological diagnosis of SCC of the tongue were selected. The control group was composed of 10 matched patients with no clinical evidence of tongue lesions. Polymerase chain reaction (PCR) was used to detect the presence of HPV genome in fresh-frozen tissue specimens from SCC of the tongue margin. Thirty-seven patients (74%) had a positive PCR for oncogenic papillomavirus, and only 1 specimen (10%) of the control group was positive for nononcogenic papillomavirus. Based on the statistical analysis of this study there was a 25.6% higher risk for SCC of the tongue to harbor oncogenic HPV than the healthy control tongue tissue.     

Genetic disorders and bone affecting the craniofacial skeleton

Genetic disorders of bone constitute a large number of alterations approaching almost 300 types. This article focuses on the most common disorders in this group, which at the same time are the most clinically significant because of their incidence and degree of involvement of the craniofacial skeleton.     

Monocyte chemoattractant protein-1 and atherosclerosis: is there room for an additional biomarker?

Atherosclerosis is an inflammatory disease in which several chemokines are implicated. The roles of these molecules extend from the recruitment of circulating inflammatory cells to the activation of inflammatory and pro-thrombotic cascades, which ultimately leads to an atherosclerosis-related event. One of the most studied chemokines is monocyte chemoattractant protein-1 (CCL2), which has been strongly linked to atherosclerosis in both animal and human studies. The higher the expression of either the CCL2 gene or its receptor CCR-2, the higher the likelihood of developing atherosclerosis in genetically-modified animals. Conversely, the deletion of either CCL2 or its receptor is followed by a significant reduction in the development of atherosclerotic plaques. Studies in humans yield controversial results. Most of these studies linked the plasma CCL2 concentration to the occurrence of atherosclerosis or related events; however, this relationship does not seem to be independent of the classical, known risk factors. Currently, there are no suitable analytical tools to reach strong conclusions with respect to the value of plasma CCL2 concentration as a biomarker of atherosclerosis, but experimental evidence suggests that the CCL2/CCR2 pathway should be further explored as a diagnostic, prognostic and therapeutic target.     

New pharmaceutical approaches for the treatment of food allergies

Introduction: Allergic diseases constitute one of the most common causes of chronic illness in developed countries. The main mechanism determining allergy is an imbalance between Th1 and Th2 response towards Th2.

Areas covered: This review describes the mechanisms underlying the natural tolerance to food components and the development of an allergic response in sensitized individuals. Furthermore, therapeutic approaches proposed to manage these abnormal immunologic responses food are also presented and discussed.

Expert opinion: In the past, management of food allergies has consisted of the education of patients to avoid the ingestion of the culprit food and to initiate the therapy (e.g. self-injectable epinephrine) in case of accidental ingestion. In recent years, sublingual/oral immunotherapies based on the continuous administration of small amounts of the allergen have been developed. However, the long periods of time needed to obtain significant desensitization and the generation of adverse effects, limit their use. In order to solve these drawbacks, strategies to induce tolerance are being studied, such as the use of either adjuvant immunotherapy in order to facilitate the reversion of the Th2 response towards Th1 or the use of monoclonal antibodies to block the main immunogenic elements.