Comparative Micro–computed Tomographic Evaluation of the Sealing Quality of ProRoot MTA and MTA Angelus Apical Plugs Placed with Various Techniques

Introduction

This study compared the effects of different mixing and placement techniques on sealing of ProRoot MTA (Dentsply Maillefer, Ballaigues, Switzerland) and MTA Angelus (Soluçoes Odontologicas, Londrina, Brazil) apical plugs using micro–computed tomographic (micro-CT) imaging.

BioAggregate和MTA对体内破骨细胞分化和功能的影响

目的研究口腔生物陶瓷材料Bio Aggregate及MTA对体内LPS诱导的炎性骨吸收的影响。方法 6周龄C57/BL6雄性小鼠随机分为四组:PBS组、LPS组、Bio Aggregate+LPS组和MTA+LPS组,每组6只。LPS干预小鼠7 d后,取出颅盖骨进行显微-CT扫描、HE染色、酶组织化学染色和组织免疫荧光染色,观察骨破坏面积、破骨细胞的形成以及组织蛋白酶K(cathepsin K)的表达。结果 Bio Aggregate和MTA浸提液明显减少LPS诱导的破骨细胞形成和小鼠颅盖骨炎性骨破坏。与破骨细胞功能密切相关的组织蛋白酶K的表达在Bio Aggregate和MTA浸提液的作用下被显著下调。结论新型口腔生物陶瓷材料Bio Aggregate和传统材料MTA能够抑制体内炎性骨吸收。     

Anti-inflammatory and Mineralization Effects of ProRoot MTA and Endocem MTA in Studies of Human and Rat Dental Pulps In Vitro and In Vivo

Introduction

Few studies have reported direct pulp capping in inflamed pulp conditions. The purpose of this study was to investigate the in vitro and in vivo responses of dental pulp during direct pulp capping using various pulp capping materials in inflamed conditions.

FTIR characterization of the setting reaction of biodentine™

Objective

To provide insight of the setting reactions of Biodentine?, a hydraulic calcium silicate cement, based upon observations using Fourier Transform Infra-Red (FTIR) spectroscopy.

Clinical Application and Effects of the Forsus™ Spring A Study of a New Herbst Hybrid

BACKGROUND: The best known of the fixed functional appliances are the Herbst appliance and the Jasper Jumper. The Forsus spring is a new development which has been tested in a clinical study to establish when it can be used and to compare it with its predecessors. PATIENTS AND METHOD: The Forsus spring was used over a period of 4 months to treat 13 patients with an average age of 14.2 years with Class II malocclusion. RESULTS: Evaluation of the lateral cephalograms showed that dental effects accounted for 66% of the sagittal correction. The sagittal occlusal relations were improved by approximately 3/4 of a cusp width to the mesial on both the right and left side as a result of distal movement of the upper molars and mesial movement of the lower molars. Retrusion of the upper and protrusion of the lower incisors reduced the overjet by 4.6 mm. Intrusion and protrusion of the lower incisors reduced the overbite by 1.2 mm. The occlusal plane was rotated by 4.2 degrees in clockwise direction as a result of intruding the lower incisors and the upper molars. The maxillary and mandibular arches were expanded at the front and rear during treatment.--Evaluation of a questionnaire filled in by the patients after 2 months of treatment showed that approximately half of them had experienced difficulties in brushing their teeth. The main problem, however, was the restriction experienced in the ability to yawn. Overall, two thirds of the adolescents found the Forsus spring better than the appliance previously used to correct their Class II malocclusion, such as headgear, activator or Class II elastics. CONCLUSION: The Forsus spring has stood the test in clinical application. It is a good supplement to the Class II appliance systems already available.     

Clinical Applications of the TMJ Scale™

The clinical use of the TMJ Scale? with individual patients having TM disorders is described using several case examples. Areas of predicted physical and psychosocial dysfunction using this test agree well with history and clinical examination results in these patients. The case examples demonstrate the capability of the TMJ Scale to detect and describe the multidimensional symptom state found in individual patients having complex TM disorders.     

Characterization of health complaints before and after removal of amalgam fillings — 3-year follow-up

Abstract

Objective. Some patients attribute health complaints to amalgam fillings and report improvement of health after replacement of amalgam fillings. The aim of the present study was to characterize the changes of different health complaints after replacement of amalgam fillings and compare with an external reference group from the general population. Materials and methods. The study group included 20 patients with health complaints attributed to amalgam fillings who were participants in the treatment group of a clinical trial at the Norwegian Dental Biomaterials Adverse Reaction Unit. The patients were asked to indicate the intensity of local and general health complaints on numeric rating scales (0–10) before removal of amalgam fillings and at follow-up 3 years after removal. Data from the patient group were compared with data from an external reference group (n = 441). Results. Before treatment the mean intensity of complaints were on a higher level in the treatment group compared to the reference group. The most frequently reported complaints in the treatment group were gastrointestinal symptoms, fatigue, pain from muscles and joints, symptoms from ear/nose/throat and difficulty concentrating. From pre-treatment examination to the 3-year follow-up 20 of 23 health complaints decreased, being statistically significant for taste disturbances, pain from muscles and joints, gastrointestinal complaints, complaints from ear/nose/throat and fatigue. Conclusions. The inter-individual variation of intensities of health complaints was considerable and the reduction of health complaints varied for the different complaints. Several factors may be of importance for the observed reduction of complaint intensity.     

Clinical and antimicrobial efficacy of NitrAdine ™-based disinfecting cleaning tablets in complete denture wearers

Objective

This study evaluated the efficacy of NitrAdine^TM-based disinfecting cleaning tablets for complete denture, in terms of denture biofilm removal and antimicrobial action.

Material and methods

Forty complete denture wearers (14 men and 26 women) with a mean age of 62.3±9.0 years were randomly assigned to two groups and were instructed to clean their dentures according to two methods: brushing (control) - 3 times a day with denture brush and tap water following meals; brushing and immersion (experimental) - brushing the denture 3 times a day with denture brush and tap water following meals and immersion of the denture in NitrAdine^TM-based denture tablets (Medical Interporous^TM). Each method was used for 21 days. Denture biofilm was disclosed by a 1% neutral red solution and quantified by means of digital photos taken from the internal surface before and after the use of the product. Microbiological assessment was conducted to quantify Candida sp.

Results

An independent t-test revealed a significant lower biofilm percentage for the experimental group (4.7, 95% CI 2.4 to 7.9) in comparison with the control group (mean 37.5, 95% CI 28.2 to 48.1) (t38=7.996, p<0.001). A significant reduction of yeast colony forming units could be found after treatment with Medical Interporous^TM denture tablets as compared to the control group (Mann-Whitney test, Z=1.90; p<0.05).

Conclusion

The present findings suggest that NitrAdine^TM-based disinfecting cleaning tablets are efficient in removal of denture biofilm. In addition, a clear antimicrobial action was demonstrated. Therefore, they should be recommended as a routine denture maintenance method for the prevention of the development of microbial biofilm-induced denture stomatitis.     

Chemical–physical properties of experimental root canal sealers based on butyl ethylene glycol disalicylate and MTA

Objective

The aim of this study was to evaluate the calcium release, pH, flow, solubility, water absorption, setting and working time of three experimental root canal sealers based on mineral trioxide aggregate (MTA) and two forms of calcium phosphates (CaP).

Methods

The materials were composed of a base and a catalyst pastes mixed in a 1:1. The base paste was made by 60% bismuth oxide and 40% butyl ethylene glycol disalicylate. Three different catalyst pastes were formulated containing 60% MTA or 40% MTA + 20% CaP (hydroxyapatite HA or dibasic calcium phosphate dehydrate DCPD), 39% Resimpol 8% and 1% titanium dioxide. MTA Fillapex was used as control. The release of calcium and hydroxyl ions, solubility and water absorption were measured on regular intervals for 28 days. The working time and flow were tested according to ISO 6876:2001 and the setting time according to ASTM C266. The data were analyzed using 1-way ANOVA with Tukey's test (p < .01).

Results

All the cements showed basifying activity and released calcium ions. MTA Fillapex showed the highest values of flow (p < .01) and working/setting times (p < .01) and the smallest values of solubility (p < .01) and water absorption (p < .01).

Significance

All experimental materials showed satisfactory physical–chemical properties to be used as endodontic sealers in clinical practice.     

Characterization of two Ni–Cr dental alloys and the influence of casting mode on mechanical properties

PurposeThe aim of this study was to evaluate the tensile strength, elongation, microhardness (MHV), composition and microstructure of two Ni–Cr based alloy, cast under different casting conditions.MethodsBefore casting, the alloy ingots were evaluated as regards composition (EDX) and microstructure (Optical microscopy, SEM and EDX). The casting conditions were as follows: electromagnetic induction in an environment controlled with argon (EWA), electromagnetic induction in an environment under vacuum (EWV), electromagnetic induction without atmosphere control (EWNC) and blowtorch (BT). For each condition, 16 specimens were obtained, each measuring 25 mm high and 2.5 mm in diameter. The ultimate tensile strength (UTS) and elongation (EL) tests were performed in a Kratos machine (1.0 mm/min). Fractured specimens were embedded in bakelite resin and polished for Vickers Microhardness analysis (1000 g/10 s) with 4 penetrations in each specimen. The UTS, EL and MHV results were evaluated for two-way ANOVA and Tukey's test (α = 0.05).ResultsThe cross-product interaction was statistically significant for all properties evaluated (p < 0.0001), lower UTS, VHN and higth elongation means were observed for the Ni–Cr–Mo–Be alloy tested when cast under the induction/argon (p < 0.05). Higher UTS means were found for Ni–Cr–Mo–Ti alloy tested when cast under the induction/vacuum, and induction/air and flame/air condition (p < 0.05). The two alloys show a microstructure with a dendritic formation with the presence of eutectic presence.ConclusionThe Ni–Cr–Mo–Ti alloy showed higth UTS, MHV and lowest EL comparaded with the tradicional Ni–Cr–Mo–Be, that show lowest UTS, MHV and higter EL when cast on induction/argon.     

Effect of Carisolv™ solution on sound, demineralized and denatured dentin – an ultrastructural investigation

The purpose of this in vitro study was to analyze the micromorphological changes caused by Carisolv^™ gel on sound, demineralized, and denatured dentin. Fractured dentinal surfaces, dentinal surfaces demineralized superficially by phosphoric acid etching and dentinal surfaces denatured due to lactic acid and collagenase pretreatment were exposed to freshly mixed Carisolv^™ gel or 0.25% sodium hypochlorite. No additional mechanical action was exerted during the 20-min exposure of specimens to the Carisolv^™ solution. Specimens were evaluated by transmission electron microscopy. Electron microscopic evaluation did not indicate any ultrastructural changes of the fractured or demineralized dentinal surfaces due to the 20-min Carisolv^™ treatment. Denatured dentin was partially removed within a 20 min period of chemical action of the Carisolv^™ solution leaving only a 1- to 2-μm thick layer of residual denatured dentin on the specimen’s surface. In contrast, 0.25% sodium hypochlorite treatment completely dissolved the demineralized as well as denatured dentin layer within 20 min. It is concluded that Carisolv^™ gel (1) does not affect sound fractured dentin, (2) does not dissolve demineralized dentin, and (3) has a limited potential to chemically dissolve denatured dentin. Received: 30 June 1999 / Accepted: 13 July 1999     

Remineralizing effect of calcium-sucrose-phosphate with and without fluoride on primary and permanent enamel: Microhardness and quantitative-light-induced-fluorescence™ based in vitro study

ObjectiveTo evaluate and compare remineralization potential of commercially available calcium sucrose phosphate (CaSP) (5% EnaFix) individually and with 0.2% Sodium Fluoride (NaF) mouth-rinse (ACT Kids Anticavity Fluoride-Rinse) supplementation through Vickers Microhardness tester (VMH) and Quantitative Light Induced Florescence (QLF?) technology on artificial carious lesions on primary and permanent enamel.Materials & methodsIn present in-vitro comparative study, artificial carious lesions were created on 60 each, permanent and primary enamel samples followed by pH cycling for a period of 21 days with interventional agents (Control; Distilled water; Test; CaSP alone and CaSP + 0.2% NaF). The samples were evaluated for ΔF values of QLF at, demineralization, 7th, 14th and 21st day and VHN at, demineralization and 21st day of pH cycling. The data were analysed using paired t-test and ANOVA.ResultsIntra group comparison showed the statistically significant fluorescence gain with CaSP+0.2%NaF in permanent samples and statistically significant fluorescence gain with both CaSP and CaSP+0.2%NaF in primary samples (p = 0.001). Inter group comparison of interventional agents in both primary and permanent samples showed statistically non-significant variation between CaSP and added NaF group (p = 0.68).ConclusionsWithin the limitations of the present study, results showed no significant difference in microhardness improvement and remineralization potential between CaSP and CaSP+0.2%NaF. However, since both showed similar efficacy CaSP looks to be a choice for primary dentition and CaSP with 0.2% NaF can be preferred for mixed dentition with primary and young permanent teeth.     

YouTube™ as a source of information on extraction of third molars

Oral and Maxillofacial Surgery - Healthcare information is becoming more readily available and searched for online, particularly on websites such as YouTube?. The accuracy and content of...