bluuebunny/crossref_metadata_2025 huggingface dataset:
Marked papillary dermal edema – an unreliable discriminator between polymorphous light eruption and lupus erythematosus or dermatomyositis
Authors: Pincus Laura B. , LeBoit Philip E. , Goddard Deborah S. , Cho Raymond J. , McCalmont Timothy H.
Published: February 2010

Background: The clinical differential diagnosis of photo‐distributed papules and plaques includes polymorphous light eruption (PMLE) and lupus erythematosus (LE). These entities share many histopathological features. However, in most contemporary textbooks, a broad band of papillary dermal edema is reported to be characteristic of PMLE and not seen in LE. Nonetheless, older reports describe papillary dermal edema in LE, including acute cutaneous LE (ACLE) in patients with systemic LE (SLE) and early lesions of discoid lupus erythematosus (DLE). Older reports also describe papillary dermal edema in microscopic sections of dermatomyositis (DM).

Methods: Retrospective review.

Results: Nine cases of LE (including two patients with acute lesions of SLE, six with DLE and one unclassifiable) and three cases of DM were identified in which sections showed striking papillary dermal edema. Attributes of chronicity, such as epidermal atrophy, follicular plugging and basement membrane thickening, were present concurrently in many sections.

Conclusions: Marked papillary dermal edema does not reliably distinguish PMLE from LE as it can be seen in ACLE, early and late lesions of DLE and DM. This phenomenon has been underemphasized in recent reports and textbooks. Furthermore, papillary dermal edema in chronic lesions of DLE has not been previously reported.

Pincus LB, LeBoit PE, Goddard DS, Cho RJ, McCalmont TH. Marked papillary dermal edema – an unreliable discriminator between polymorphous light eruption and lupus erythematosus or dermatomyositis.
ENMTools: a toolbox for comparative studies of environmental niche models
Authors: Warren Dan L. , Glor Richard E. , Turelli Michael
Published: February 2010

We present software that facilitates quantitative comparisons of environmental niche models (ENMs). Our software quantifies similarity of ENMs generated using the program Maxent and uses randomization tests to compare observed similarity to that expected under different null hypotheses. ENMTools is available online free of charge from .
The anti‐apoptotic protein G1P3 is overexpressed in psoriasis and regulated by the non‐coding RNA, PRINS
Authors: Szegedi Krisztina , Sonkoly Enikő , Nagy Nikoletta , Németh István Balázs , Bata‐Csörgő Zsuzsanna , Kemény Lajos , Dobozy Attila , Széll Márta
Published: February 2010

Please cite this paper as: The anti‐apoptotic protein G1P3 is overexpressed in psoriasis and regulated by the non‐coding RNA, PRINS. Experimental Dermatology 2010; 19: 269–278.

Abstract:  Psoriasis Susceptibility‐Related RNA Gene Induced by Stress (PRINS) is a non‐coding RNA overexpressed in lesional and non‐lesional psoriatic epidermis and induced by stress. Its function in healthy and psoriatic skin is still not known. Here, we report that PRINS regulates G1P3, a gene with anti‐apoptotic effects in keratinocytes. siRNA‐mediated inhibition of PRINS gene resulted in altered cell morphology and gene expression alterations, as demonstrated in a microarray experiment. One of the genes regulated by PRINS ncRNA was G1P3, an interferon‐inducible gene with anti‐apoptotic effects in cancer cells. Interestingly, we found that G1P3 was 400‐fold upregulated in hyperproliferative lesional and ninefold upregulated in non‐lesional psoriatic epidermis compared to healthy epidermis. In vitro, G1P3 protein levels were highest in proliferating keratinocytes and siRNA‐mediated downregulation of G1P3 resulted in increased cell apoptosis. These data indicate that G1P3 inhibits spontaneous keratinocyte apoptosis and hence its high expression in psoriatic skin may contribute to the development of psoriatic lesions. We hypothesize that the deregulation of the PRINS ncRNA may contribute to psoriasis and results in decreased sensitivity to spontaneous keratinocyte apoptosis via the regulation of G1P3.
Molecular analysis of the CART gene in overweight and obese Italian children using family‐based association methods
Authors: Rigoli L , Munafò C , Di Bella C , Salpietro A , Procopio V , Salpietro C
Published: February 2010

Aim:  In our study, we evaluated if CART gene A1475G and ΔA1457 polymorphisms could be associated with obesity.

Patients and methods:  We recruited 133 Italian trios from among 103 (50 males and 53 females) overweight children (mean age 10.5 years, range 6–14 years; mean BMI 26.1 ± 3.2 kg/m2), and 30 (16 males and 14 females) obese children (mean age 9.0 years, range 6–11 years; mean BMI 32.3 ± 2.0 kg/m2). We also selected 187 non‐obese unrelated controls.

Results:  The allele frequencies of the A1475G single nucleotide polymorphism (SNP) were significantly higher in overweight children (0.07) than in control children (0.02) (p = 0.03) and control adults (0.02) (p = 0.02). Moreover, the allele frequencies were significantly different between obese children (0.08) and control children (0.02) (p = 0.03), and between obese children (0.08) and control adults (0.02) (p = 0.02). The ΔA1457 SNP showed no significant association with overweight/obesity. TDT statistic revealed a preferential transmission of the 1475G allele from heterozygous parents to overweight children (p < 0.01) and to obese children (p < 0.05). No statistically significant excess transmission of the ΔA1457 allele was found.

Conclusion:  Our results supported the hypothesis that inherited variations of the CART gene could influence the development of obesity also in Italian children.
Neonatal renal vein thrombosis and prothrombotic risk
Authors: Harris SL , Smith MP , Laurie A , Darlow BA
Published: February 2010

A case of extensive deep venous thrombosis in a four a day old infant was presented. Unusually this patient was shown to be heterozygous for three thrombophilia genes; Factor V Leiden, prothrombin and antithrombin gene mutations, the latter being novel.

Conclusion: There are no randomized controlled trials to guide management in deep venous thrombosis in the newborn but knowledge of the prothrombotic risk factors may help direct treatment.
Immediate Rehabilitation of the Extremely Atrophic Mandible with Fixed Full‐Prosthesis Supported by Four Implants
Authors: Weinstein Roberto , Agliardi Enrico , Fabbro Massimo D. , Romeo Davide , Francetti Luca
Published: February 2010

Purpose: To prospectively assess the outcome of immediate rehabilitation of extremely atrophic mandibles by a full‐arch fixed bridge anchored to four implants.

Material and Methods: Twenty patients with edentulous mandibles were included in the study. Each patient received a full‐arch fixed bridge supported by two axial and two distal tilted implants. Prosthetic loading was applied within 48 hours of surgery. Patients were scheduled for follow‐up every 6 months up to 2 years and annually until 5 years. Radiographic evaluation of marginal bone level change was performed at 1 year.

Results: All patients were followed for a minimum of 1 year (range 20–48 months, mean 30.1 months). No failures were recorded to date. The 1‐year implant survival rate and prosthesis success rate were 100%. Marginal bone loss around axial and tilted implants was similar at 12‐month evaluation, being, respectively, 0.6 ± 0.3 (standard deviation) mm and 0.7 ± 0.4 mm. High patient's level of satisfaction was recorded for function, phonetics, and aesthetics.

Conclusion: This technique could be considered a viable treatment option for the rehabilitation of the atrophic mandible.
Effect of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin suggests abnormal palate development after palatal fusion
Authors: Imura Hideto , Yamada Tomohiro , Mishima Katsuaki , Fujiwara Kumiko , Kawaki Harumi , Hirata Azumi , Sogawa Norio , Ueno Takaaki , Sugahara Toshio
Published: February 2010

Mouse embryos exposed to 2,3,7,8‐tetrachloridedibenzo‐p‐dioxin (TCDD) develop cleft palates and hydronephrosis. Cleft palates occur after TCDD exposure due to contact and/or fusion failure. We investigated whether cleft palate can be induced by dissociation of the palatine process after fusion. Pregnant mice on gestational day (GD) 12 were randomly divided into two groups: one group was administered through gastric tubes one dose of olive oil (control group) and the other group was administered one dose of TCDD diluted with olive oil, both at a dose of 40 µg/kg body weight. Embryos were removed by cesarean section from pregnant mice during the palatal formation stage (GD 13–18) and the palatal form was observed using a stereoscopic microscope. In TCDD‐exposed embryos, palatal fusion was observed on GD 14, 15 and 16 and the incidence of cleft palate was 100% on GD 18. Fusion rates were 17.5 ± 15.2% and 12.4 ± 11.8% on GD 15 and 16, respectively. Some palates from the TCDD‐exposed mouse embryos showed clearly developed cleft palate after fusion of the lateral palatine processes during palatal formation. A mass of cells, which were chiefly epithelial in the fused palates was observed in the TCDD‐exposed mouse embryos. A decrease in E‐cadherin expression was observed in this mass of cells, indicating its involvement in the development of cleft palate.
Effect of recombinant human fibroblast growth factor‐2 on bone formation in rabbit mandibular distraction models using β‐tricalcium phosphate
Authors: Higuchi Yusuke , Kabasawa Yuhji , Sato Masaru , Kikuchi Tsuyoshi , Aoki Kazuhiro , Ohya Keiichi , Maruoka Yutaka , Omura Ken
Published: February 2010

This study was designed to evaluate the effect of recombinant human fibroblast growth factor‐2 (rhFGF‐2) on the amount and period of new bone formation in rabbit mandibular distraction models using β‐tricalcium phosphate (β‐TCP) as a bone graft substitute. Sixteen male Japanese White rabbits were divided into the following four experimental groups: 1, distraction alone; 2, distraction with β‐TCP granules; 3, distraction with rhFGF‐2 (25 µg/50 µL) injected into β‐TCP granules; and 4, distraction with rhFGF‐2 (100 µg/50 µL) injected into β‐TCP granules. The bones were harvested at 4 weeks after the operation and examined using soft radiography, micro‐computed tomography (micro‐CT), and peripheral quantitative computed tomography (pQCT). The dissected mandibles were stained using the Villanueva bone staining method, and the amount of new bone formed, bioresorption of β‐TCP, and new blood vessel formation were morphometrically calculated using bone histomorphometry. Radiopaque areas were observed more frequently in the distracted area of groups 3 and 4. Micro‐CT analysis revealed partial new bone formation in the central region of the distracted area in groups 3 and 4. pQCT analysis revealed increased bone mineral density in groups 3 and 4. Histomorphometric analysis revealed increased newly formed bone and blood vessel areas in groups 3 and 4. In group 4, the number of osteoclasts around the β‐TCP granules had significantly increased. The present findings suggested that the combined use of rhFGF‐2 and β‐TCP reduced the treatment period for distraction osteogenesis and accelerated the formation of a new high‐quality bone.
An investigation of the relationship between hullability and morphological features in grains of four oat varieties
Authors: White E. , Watson S.
Published: February 2010

Milling of oats involves separation of the kernel from its enclosing husk. The ease with which this happens is termed ‘hullability’. The association between morphological characteristics measured using image analysis and hullability was examined in oat varieties sampled from Recommended List variety trials conducted at AFBI Crossnacreevy, Belfast, UK in 2000 and 2006. Grain features of the varieties were distinctive and showed differing relationships with weight, Barra changing only slightly, whilst Mascani showed the maximal changes with increasing grain weight. Hullability was poorer in larger grain, and better in Barra and Mascani than in Gerald and Tardis. Fitting of exponential models for the percentage of hulled grain with dehulling duration identified features associated with different aspects of dehulling behaviour. Greater width of grains of Mascani and Tardis was associated with a more rapid increase in hullability at shorter durations of dehulling. Greater roundness in Barra and Gerald in 2000 was associated with better hullability at very short durations of dehulling relative to other varieties. It is concluded that these features of the grain could be of use in selecting high hullability in breeding programmes.
Nematicidal activity of powder and extracts of Melia azedarach fruits against Meloidogyne incognita
Authors: Ntalli N.G. , Menkissoglu‐Spiroudi U. , Giannakou I.
Published: February 2010

Pulverised lyophilised (dehydrated) Melia azedarach (Meliaceae) fruits (PMF) were tested in a dose–response pot experiment against juveniles (J2) of the root‐knot nematode Meloidogyne incognita. Successively, with different extraction procedures, a polar (melia methanol extract, MME) and a non‐polar (melia oil, MO) fragments were obtained and their effects were tested on nematode motility and development, in dose and time response bioassays and pot experiments. An EC50 value was calculated for all experiments. A dose–response effect was found in pot bioassays using PMF and, after an incubation period of 24 and 48 h, the EC50 values were calculated at 0.41% and 0.34% w/w, respectively. Motility bioassays revealed a dose and time dependent response effect, after exposure to MME, but not to MO. Doses of MME higher than 0.08% were nematicidal, whereas lower ones were nematostatic (the loss of motility as a result of the presence of the substance was reversible). In a pot experiment, MME doses higher than 2.5% w/w caused 100% nematode control with EC50 value of 0.916% w/w.
Interspecies and intergenus transferability of barley and wheat D‐genome microsatellite markers
Authors: Castillo A. , Budak H. , Martín A.C. , Dorado G. , Börner A. , Röder M. , Hernandez P.
Published: February 2010

A selection of 147 wheat D‐genome and 130 barley genomic simple sequence repeat (gSSR) markers were screened for their utility in Hordeum chilense, as an alien donor genome for cereal breeding. Fifty‐eight wheat D‐genome and 71 barley PCR primer pairs consistently amplified products from H. chilense. Nineteen wheat D‐genome and 20 barley gSSR markers were polymorphic and allowed wide genome coverage of the H. chilense genome. Twenty‐three of the wheat D‐genome and 11 barley PCR primer pairs were suitable for studying the introgressions of H. chilense into wheat, amplifying H. chilense products of distinct size. In 88% of the markers tested, H. chilense products were maintained in the expected homeologous linkage group, as revealed by the analysis of wheat/H. chilense addition lines. Twenty‐nine microsatellite markers (eight gSSRs and 21 expressed sequence tags‐SSRs) uniformly distributed across the genome were tested for their utility in genetic diversity analysis within the species. Three genetic clusters are reported, in accordance with previous morphological and amplified fragment length polymorphism data. These results show that it is possible to discriminate the three previously established germplasm groups with microsatellite markers. The reported markers represent a valuable resource for the genetic characterisation of H. chilense, for the analysis of its genetic variability, and as a tool for wheat introgression. This is the first intraspecific study in a collection of H. chilense germplasm using microsatellite markers.
CHEMICAL COMPOSITION, THERMAL AND VISCOELASTIC CHARACTERIZATION OF TUBER STARCHES GROWING IN THE YUCATAN PENINSULA OF MEXICO
Authors: CHEL‐GUERRERO L. , CRUZ‐CERVERA G. , BETANCUR‐ANCONA D. , SOLORZA‐FERIA JAVIER
Published: February 2010

Optical microscopy, proximate analysis, differential scanning calorimetry and rheological oscillatory tests were done to evaluate the physical, thermal and rheological properties of starches isolated from the tubers makal (Xanthosoma yucatanensis), sweet potato (Ipomea batata), cassava (Manihot esculenta) and sago (Marantha arundinacea). Mean starch granule size ranged from 10.6 to 16.5 µm. Makal and sweet potato starch granules were spherical, cassava starch granules were spherical‐truncated and sago starch granules were polygonal.

The proximate composition showed that overall, the starches studied were within the group of the normal ones, with low fat and protein content (<7%) and amylose content <30%. Gelatinization peak temperature range was 61.3 to 78.4C and enthalpy (ΔH) range was 9.2 to 14.9 J/g. The rheological profiles of all tuber starches exhibited viscoelastic gel‐like behavior with G′ (storage modulus) > G″ (loss modulus) at the tested amplitude and frequency ranges. Makal and sago starches are potentially useful in the manufacture of products requiring high processing temperatures. Sweet potato starch may have applications in food systems as a thickening and gelling agent, while cassava starch could be used to stabilize low viscosity foods.

PRACTICAL APPLICATIONS

Starch is a fundamental element of human diets and is used extensively as a functional ingredient. However, despite a global production of 48.5 million tons/annum, part of the worldwide demand remains unmet, meaning new starch isolation sources are needed (FAOSTAT 2001). With worldwide cultivation of approximately fifty million hectares (CIAT 1997), roots and tubers play a significant role in the global food system and are a vital caloric source for people in many developing countries. In Mexico, the most common cultivated roots and tubers are cassava, potato, makal, sweet potato, sago and yam bean, all most frequently eaten in the country's southeastern states (Burgos‐Perez 2005), with scarce information available about its properties. When determining the potential uses of a starch in food systems, the chemical, thermal and rheological behaviors of its pastes and gels (Wang and White 1994) are most important. Thus, results of this study may decide specific application (thickening, flow and gelling agent) of local starches in the food industry.
When All Else Fails …
Authors: Cohn Steven A.
Published: February 2010

Endodontic surgery may be indicated if orthograde endodontic treatment cannot be carried out or is unsuccessful. Advances in instruments, materials and techniques have made surgical endodontics a more predictable procedure. A complex case that required surgical intervention is presented to illustrate this point.
Contemporary Endodontology
Authors: Spångberg Larz S. W.
Published: February 2010

Clinical endodontics has made significant progress during this century. This lecture will critically review the major breakthroughs that have taken place during this period. The final judgement of the value of this progress, however, is the quality of care we can deliver to our patients. Although the advances have been impressive, there are also major disappointments and problems that need to be recognised. Looking at clinical endodontics today, there is clearly a dissonance between sound scientific knowledge and empirical clinical practice. It is important that these problems are recognised and that endodontic research and teaching are refocused. Only by decisive action can progress be assured for clinical endodontics and the prospect will be bright.
Part 3: But Doctor, My Ear Hurts
Authors: Kah Melissa
Published: February 2010

Temporomandibular disorders (TMD) can present as an array of symptoms that can mimic both odontogenic and ear, nose, and throat (ENT) disorders. Dentists need to be alert to the possibility of primary ENT disorders in patients who present with TMD symptoms, as should ENT physicians be familiar with the clinical presentation of TMD, especially in those patients who present with ENT symptoms but no sign of ENT disease.
The Problem Of Dentoalveolar Ankylosis And Subsequent Replacement Resorption In The Growing Patient
Authors: Andersson Lars , Malmgren Barbro
Published: February 2010

Dentoalveolar ankylosis is a serious complication following injuries of the periodontal membrane in severe dental trauma such as avulsion and intrusion. The condition is a fusion of the alveolar bone with the tooth. The consequences of this condition are progressive resorption of the root with replacement by bone (replacement resorption) and arrested growth of the alveolar process in the growing patient. This article will present an overview of dentoalveolar ankylosis and replacement resorption and its problems, treatment options and prognosis. especially focusing on the growing patient.
Treatment Of Middle‐Apical Level Root Fracture In Necrotic Teeth
Authors: Sousa‐Neto Manoel D. , Santos Erlei. S. , Estrela Carlos , Saquy Paulo César , Pécora Jesus D.
Published: February 2010

The purpose of this paper is to present two case reports of dental trauma with middle‐apical level root fractures and pulp necrosis. The treatment consisted of programmed applications of calcium hydroxide until a calcified barrier was formed at the fracture level. The technique presented here proved efficient in treating horizontal fractures at the middle and apical thirds of the root.
Management Of Acute Dento‐Alveolar Trauma – From The Viewpoint Of An Oral Surgeon
Authors: Kølsen Petersen Jens
Published: February 2010

Oral and maxillofacial surgeons often deal with acute dento‐alveolar trauma in hospital or practice surroundings. They are often called upon by dental colleagues to give their advice or help in a given situation of the acute trauma patient with dental or oral injuries. In this article, the practical viewpoints and clinical experiences of an oral surgeon are offered based upon many years of work in hospital emergency rooms around the world.
Management Of Post‐Treatment Endodontic Disease: A Current Concept Of Case Selection
Authors: Friedman Shimon
Published: February 2010

Over 30% of root filled teeth in the population present with endodontic infective disease, which has either persisted or emerged after treatment. Management of these “failed” cases is a challenge to the clinician, at the levels of diagnosis, case selection, communication and decision, and that is even before techniques are considered. Diagnosis should differentiate between endodontic and other aetiologies, and focus on the site of infection. Case selection should be based on how best to control the infection, but also on the benefit‐risk balance of the alternative treatment modalities, the attitudes of the patient and the capability of the clinician. All of the above must be communicated to the patient, who then should make the informed decision regarding the selected treatment. This article discusses the treatment rationale, diagnosis, case selection and communication related to post‐treatment endodontic disease.
Prevalence Of Prevotella Intermedia And Prevotella Nigrescens In Infected Root Canals From A Brazilian Population
Authors: Siqueira José , Rôças Isabela N. , Oliveira Julio Cezar M.
Published: February 2010

The purpose of the present study was to evaluate the prevalence of Prevotella intermedia and Prevotella nigrescens in symptomatic and asymptomatic endodontic infections from a Brazilian population. DNA extracted from samples obtained from 28 cases of endodontic infection were examined by the 16S rDNA‐directed Polymerase Chain Reaction (PCR) method. PCR detected P. intermedia in 7.1% of the cases (2 out of 28 teeth) and P. nigrescens in only one sample (3.6%). The low prevalence of P. intermedia and P. nigrescens as reported in the present study is probably justified for geographical reasons.
Apical Sealing Ability Of Five Endodontic Sealers
Authors: Siqueira José F. , Rĉças Isabela N. , Valois Caroline R.A.
Published: February 2010

Because apical leakage may be a cause of failure of endodontic treatment, the purpose of this study was to compare the apical seal provided by five endodontic sealers. After cleaning and shaping procedures, the root canals of 75 human cuspids were obturated by lateral condensation using guttapercha and the following sealers: Kerr Pulp Canal Sealer EWT, Grossman's sealer, ThermaSeal, Sealer 26, and AH Plus. These root‐filled teeth were then maintained at 37°C and 100% humidity for two days. After immersion in a solution containing black India ink and fetal bovine serum for five days, the teeth were demineralised and rendered transparent. The extent of dye penetration was examined under a stereomicroscope. The results showed that Grossman's sealer exhibited significantly more leakage than the other sealers, except ThermaSeal. There was no significant difference between ThermaSeal and AH Plus. No significant differences were observed for Kerr Pulp Canal Sealer EWT when compared with either ThermaSeal or AH Plus. There was significantly less leakage for Sealer 26 when compared with the other sealers tested, except AH Plus.
Maxillary Lateral Incisor With Two Roots
Authors: Collins Ian J.
Published: February 2010

Variations in root canal morphology can lead to complications in endodontic treatment. A case of a maxillary lateral incisor with two roots is reported.
Distribution Of The Mylohyoid Nerve: Anatomical Variability And Clinical Implications
Authors: Bennett Sam , Townsend Grant
Published: February 2010

The mylohyoid nerve is a branch of the mandibular division of the trigeminal nerve that provides motor supply to the mylohyoid and digastric muscles. Accessory innervation to the pulps of both anterior and posterior mandibular teeth by the sensory component of this nerve has been proposed to be one possible anatomical variation leading to failure of an inferior alveolar nerve block. The aim of this study was to trace the path of the mylohyoid nerve, from its origin in the infratemporal region to its terminal branches, in six human cadavers. Dissections of sagittally‐sectioned heads were performed using both medial and submandibular approaches. The anatomy of the mylohyoid nerve was variable in terms of its level of branching, course through the mylohyoid groove or canal, branch numbers to the mylohyoid and digastric muscles, and terminal branching in the submental region. In all cases the mylohyoid nerve was seen to pass down the medial surface of the ramus behind the sphenomandibular ligament.
Antifungal Effects Of Endodontic Medicaments
Authors: Siqueira José F. , Rĉças Isabela N. , Magalhäes Fernando A. C. , De Uzeda Milton
Published: February 2010

The eradication of root canal infection is paramount in endodontic treatment. Because fungi are involved in some types of root canal infections, the purpose of this study was to investigate the antifungal effects of several medicaments against the following selected fungal species: Candida albicans, Candida glabrata, Candida guilliermondii, Candida parapsilosis, and Saccharomyces cerevisiae. The agar diffusion test was the method used. Calcium sulphate or zinc oxide in glycerin showed no inhibitory effects towards any selected fungal species. The pastes of calcium sulphate or calcium hydroxide in camphorated paramonochlorophenol (CPMC)/glycerin showed the most pronounced antifungal effects. Calcium hydroxide in glycerin or chlorhexidine, and chlorhexidine in a detergent also showed antifungal activity, which was, however, much lower than the pastes of calcium sulphate or calcium hydroxide in CPMC/glycerin. Strategies using medicaments that have antifungal effects may assist in the successful management of persistent or secondary endodontic infections caused by fungi.
Mechanisms Involved In The Resistance Of Enterococcus Faecalis To Calcium Hydroxide
Authors: Evans M. , Davies J. K. , Sundqvist G. , Figdor David
Published: February 2010

Introduction

The species Enterococcus faecalis has been recovered in a high proportion of endodontic failures – approximately one‐third of failed cases with recoverable bacteria contain monoinfections of the microorganism. Eradication of E. faecalis from an infected root canal is difficult, which means that it is a significant clinical problem in endodontic treatment. E. faecalis is known to be resistant to the alkaline bactericidal effect of calcium hydroxide, yet the survival mechanisms of E. faecalis that enable it to tolerate exposure to the high pH of calcium hydroxide are poorly understood.

Because endodontic treatment involves repeated or alternate use of antimicrobial agents at various stages, these conditions could adapt or ‘pre‐treat’ cells by eliciting a stress response that enhances their survival. An ability to mount a stress response involving synthesis of general or specific stress‐induced proteins is an important survival mechanism for many bacteria. The production of these stress‐induced proteins protects cells from adverse conditions, facilitating cell recovery when more favourable conditions are re‐established. This study sought to clarify the mechanisms that enable E. faecalis to survive the high pH of calcium hydroxide.

Methods

E. faecalis strain JH2–2. was exposed to sub‐lethal concentrations of calcium hydroxide, with and without various pre‐treatments. Blocking agents were added to determine the role of stress‐induced protein synthesis and the cell wall‐associated proton pump.

Results

E. faecalis was resistant to calcium hydroxide at a pH of 11.1, but not pH 11.5. Pre‐treatment with calcium hydroxide pH 10.3 induced no tolerance to further exposure at pH 11.5. No difference in cell survival was observed when protein synthesis was blocked by Chloramphenicol during stress induction. However, addition of the proton pump inhibitor, CCCP, resulted in a dramatic reduction of cell viability of E. faecalis in calcium hydroxide.

Conclusions

This study confirmed that E. faecalis is resistant to killing by calcium hydroxide. An adaptive response in alkaline pH and stress‐induced protein synthesis do not play a role in cell survival. However, a functioning proton pump with the capacity to drive protons into the cell and acidify the cytoplasm is critical for survival of E. faecalis at high pH. These findings contribute to our understanding of the response by E. faecalis to the antimicrobial action of calcium hydroxide and may open the possibility of novel approaches to address this clinical problem in endodontic treatment.
Challenges Influencing The Future Of Endodontics. New Technologies For Endodontic Education
Authors: Cohen Stephen
Published: February 2010

The major challenge of contemporary dental education is teaching students to transfer their acquired knowledge from one setting to another. New technology‐based educational tools such as IMPACT, Interactive Multimedia Patient Case Tutor, developed at the Virginia Commonwealth University School of Dentistry, can assist in this educational paradigm shift by teaching students basic science in the context of patient dental problems. The interactivity of technology as used in the IMPACT program links students' basic science knowledge base to the description, understanding and solution of patient problems.
Dental Distress. A Possible Relief
Authors: Boundy Michael
Published: February 2010

The exacting task of endodontics can be considerably complicated by the behaviour of patients who have heightened fears and reactions to the manipulations involved. Hypnotherapy may offer a way to reduce these fears and enhance the comfort of both patient and dentist.
Where Is It Coming From?
Authors: Reid Ralph
Published: February 2010

A case report is presented of an unusual situation where standard routine diagnostic methods failed to reveal the true origin of an endodontic infection.
Engine‐Driven Preparation Of Curved Root Canals: Measuring Cyclic Fatigue And Other Physical Parameters*
Authors: Peters Ove A. , Kappeler Stefan , Bucher Willi , Barbakow Fred
Published: February 2010

An increasing number of engine‐driven rotary systems are marketed to shape root canals. Although these systems may improve the quality of canal preparations, the risk for instrument fracture is also increased. Unfortunately, the stresses generated in rotary instruments when shaping curved root canals have not been adequately studied. Consequently, the aim of an ongoing project was to develop a measurement platform that could more accurately detail physical parameters generated in a simulated clinical situation.

Such a platform was constructed by fitting a torque‐measuring device between the rotating endodontic instrument and the motor driving it. Apically directed force and instrument insertion depth were also recorded. Additional devices were constructed to assess cyclic fatigue and static fracture loads.

The current pilot study evaluated GT rotary instruments during the shaping of curved canals in plastic blocks as well as “ISO 3630–1 torque to fracture” and number of rotations required for fatigue fracture.

Results indicated that torques in excess of 40Nmm were generated by rotary GT‐Files, a significantly higher figure than static fracture loads (less than 13Nmm for the size 20. 12 GT‐File). Furthermore, the number of rotations needed to shape simulated canals with a 5 mm radius of curvature in plastic blocks was 10 times lower than the number of rotations needed to fracture instruments in a “cyclic fatigue test”. Apical forces were always greater than IN, and in some specimens, scores of 8N or more were recorded.

Further studies are required using extracted natural teeth, with their wide anatomical variation, in order to reduce the incidence of fracture of rotary instruments. In this way, the clinical potential of engine‐driven rotary instruments to safely prepare curved canals can be fully appreciated.
Vital Pulp Therapy In Cariously Exposed Permanent Teeth And Its Limitations
Authors: Ward Jeff
Published: February 2010

Vital pulp therapy for cariously exposed permanent teeth remains one of the most controversial areas in dentistry. Because a vital, functioning pulp is capable of initiating several defence mechanisms to protect the body from bacterial invasion, it is beneficial to preserve the vitality and health of an exposed pulp rather than replace it with a root filling material following pulp exposure. There is no consensus on the survival rate of formerly cariously exposed pulps. Observation time, judgement criteria, pulpotomy/pulp capping technique and, most importantly, pulpal status at the time of treatment, vary to a great extent amongst studies.

In mature teeth, a pulp exposed by caries is usually removed and the root canals are cleaned, shaped and filled. Amongst the methods for preservation of a cariously exposed pulp, partial pulpotomy has yielded a markedly high success rate in young teeth. Major limitations in the success of vital pulp therapy in cariously exposed permanent teeth exist. The lack of predictability and long‐term success greatly influence decision‐making. The decision‐making itself is unreliable primarily due to the difficulty of accurately diagnosing the ability of the pulp to repair.

While there are indications for vital pulp therapy in young permanent molars, it must be remembered that ultimately, none of these procedures enjoy the long‐term success of complete root canal therapy.
Variability Of Master Gutta‐Percha Cones
Authors: Moule Alex J. , Kellaway Richard , Glarkson Roger , Rowell John , Macfarlane Richard , Lewis Derek , Cameron Tony , Atkins Darryl
Published: February 2010

The common technique to hermetically fill prepared root canals involves the use of “standardised” guttapercha cones that are selected to fit the apical portion of the prepared canal space. These guttapercha cones are manufactured to conform to a standard size and taper which should correspond to the size and taper of standard root canal instruments. Clinical observation of commercially available guttapercha cones seemed to indicate that there is wide variation in the diameter and taper of “standardised” gutta‐percha cones within the size range 25–35. The present study was undertaken to determine how closely current commercially available gutta‐percha cones sizes 25, 30 and 35 conformed to the current ISO standard, and was initiated by the above clinical observation. It was not the purpose of this study to compare the results from different brands or manufacturers, but rather to establish whether commercially available gutta‐percha cones collectively conformed to expected standardised sizes.

One phial of cones for each of the sizes 25, 30 and 35 of eight different brands was selected for examination. The diameter of each of ten cones for each size from each brand was measured at two points, at 1 mm and at 6 mm from the tip of the cone. The results obtained for each size and each brand were tabulated and compared with ISO 6877:1995 for dental root canal obturating cones.

This study demonstrated wide variability for cones from all brands, for all sizes, when individual cones of the same size were compared. While collectively the arithmetic means showed a closer correlation to the ISO Standard, irrespective of the brand size of the cone, or whether the cone was measured at 1 mm or 6 mm, many individual cones showed a great variation from the ideal. The need for less variability is discussed. It is concluded that ISO standard 6877:1995 is inappropriate and allows for too much variation in the size of “standardised” gutta‐percha cones.
Staphylococcus epidermidis And Staphylococcus xylosus In A Secondary Root Canal Infection With Persistent Symptoms: A Case Report
Authors: Siqueira J.F. , Lima K.C.
Published: February 2010

The aim of this case report is to highlight the importance of maintaining the aseptic chain during endodontic treatment. This paper describes a clinical situation in which persistent symptoms had developed after the first appointment to treat a vital pulp case. Microbiological analysis of the case indicated that symptoms were probably due to a secondary root canal infection by two species of coagulase‐negative staphylococci — Staphylococcus epidermidis and Staphylococcus xylosus. Symptoms had persisted in spite of using various intracanal antimicrobial agents and systemic antibiotic therapy.
The Diagnosis Of Referred Orofacial Dental Pain
Authors: Ehrmann E. H.
Published: February 2010

Every patient's description of the location of pain must be treated with caution. In order to arrive at a diagnosis of pain a logical method should be employed. This consists of the history and clinical examination including pulp tests and radiographs. Where the patient complains of pain on hot or cold, an attempt should be made to reproduce the patient's pain to check on the accuracy of its description and to aid in localisation.

Patients frequently refer pain to previously endodontically‐treated teeth. These may not be the cause of the problem. In order to facilitate the process of diagnosis the following hypothesis has been advanced.

A tooth can only be the source of pain if there are objective signs associated with that tooth. Lack of response to pulp tests constitutes such a sign, provided the tooth has not previously been endodontically treated. If, however, such treatment has taken place, (regardless of whether this was well or poorly executed), a further objective sign other than lack of vitality is required before such a tooth can be implicated as the source of pain. The guidelines suggested are illustrated by means of clinical examples.
The Periapical Space — A Dynamic Interface*
Authors: Abbott Paul V.
Published: February 2010

The ultimate aim of endodontic treatment is to encourage the healing of apical periodontitis, or to prevent it from occurring if it was not present prior to treatment. Apical periodontitis is a general term used to describe an inflammatory response to irritation caused by the contents of a root canal system and it has several distinct forms. The most common is a granuloma but this can develop into other disease entities such as an abscess, a periapical pocket cyst or a true cyst, all of which present as radiolucencies. However, periapical radiolucencies may also be caused by extra‐radicular infections, foreign body reactions and periapical scars, or they may be due to other tumours and cysts that have not originated from pulp disease. Practitioners must recognise and understand the different pathological entities and the dynamic interactions that occur in the periapical tissues in order to correctly diagnose and treat these conditions.
To Do A “Root Canal”
Authors: Spångberg Larz S.W.
Published: February 2010

Endodontic treatment is often referred to as “a root canal”. This article discusses the need to be more refined and descriptive in the selection of treatment alternatives. The pathological involvement of teeth needing endodontic treatment varies significantly from superficial pulp inflammation to pulp necrosis and infection, often complicated with a periradicular osteolytic process. This diversity should lead to a variety of treatment modalities based on the severity of the disease. Failure to do so and use a one‐size‐fits‐all approach – “a root canal” – is an oversimplification and a disservice to the patient and the profession.
Cytotoxicity Of A New Endodontic Filling Material
Authors: Gambarini Gianluca , Andreasi‐Bassi M. , Bolognini G. , Testarelli L. , Nocca G. , Ceccarelli L. , Scatena R. , Lupi A. , Castagnola M.
Published: February 2010

In vitro cell cultures have been widely used as a means of evaluating cytotoxicity of root canal filling materials. Following ANSI/ADA spec. no. 41, the aim of the present study was to investigate the biological compatibility of a new sealer (FibreFill) and compare it with some commercially available endodontic sealers (Bioseal and Acroseal). Mouse 3T3 fibroblasts were seeded and cultured and subsequently extracts of the cements were added. After 24 hours incubation, the cellular vitality of fibroblasts was evaluated by the neutral red uptake test (NRU), which measures the membrane permeability. Data were collected and statistically analysed. Results showed that all tested materials exhibited mild cytotoxic effects, which are compatible with normal clinical use, and no statistically significant difference was noted between FibreFill and the other tested materials. Therefore, selection amongst these sealers should be based on other factors.
Adhesion Of A Glass‐Ionomer Root Canal Sealer To Human Dentine
Authors: Najar A.L. , Saquy P.C. , Vansan L.P. , Sousa‐Neto Manoel D.
Published: February 2010

This in vitro study evaluated the effect of smear layer removal on adhesion to human dentine of Ketac‐Endo, Grossman, and Sealer 26 root canal sealers. A total of 60 extracted human maxillary and mandibular molars with their crowns ground flat were used. The teeth were divided into two groups: Group I, the dentine surface received no treatment; Group 2, EDTA‐C was applied to the dentine surface for 5 min. Ten samples were tested for each sealer and each group. Adhesion was measured with a Universal Testing Machine. Sealer 26 showed greater adhesion both with and without smear layer (p < 0.01). Ketac‐Endo and Grossman sealers were statistically equal, having the lowest values of adhesion. Application of EDTA‐C did not alter the adhesion of Ketac‐Endo and Grossman sealers. However, the use of EDTA‐C increased the adhesion of Sealer 26. The epoxy resin‐based root canal sealer (Sealer 26) adhered better to dentine prepared with and without EDTA‐C than glass‐ionomer‐based sealers and the zinc oxide eugenol‐based (Ketac‐Endo and Grossman) sealers.
The Use Of An Ultrasonic Technique To Remove A Fractured Rotary Nickel‐Titanium Instrument From The Apical Third Of A Curved Root Canal
Authors: Ward Jeff R.
Published: February 2010

The frequency of use of nickel‐titanium rotary instruments in endodontic practice is increasing. One occasionally mentioned problem is fracture of an instrument within the root canal. The broken instrument may prevent access to the root apex, impeding optimal cleaning and shaping procedures. A case report is presented which uses a modern technique, utilising a staging platform and the use of newly designed ultrasonic tips with direct visualisation through a dental operating microscope, to remove a fractured rotary nickel‐titanium instrument from the apical third of a curved root canal.
A Comparative Analysis Of Mineral Trioxide Aggregate And Portland Cement
Authors: Funteas Urania R. , Wallace J.A. , Fochtman F.W.
Published: February 2010

The purpose of this study was to compare the composition of Portland cement and Mineral Trioxide Aggregate (MTA). Samples of MTA and Portland cement were analysed for fifteen different elements by inductively coupled plasma emission spectrometry (ICP‐ES). Comparative analysis revealed there was significant similarity except there was no detectable quantity of Bismuth in Portland cement. Quantitative results are given in both parts per million (p.p.m.) and wt%. It was concluded that there is no significant difference between the 14 different elements in both Portland cement and MTA.
Specialist Registration In Victoria – Training Of Specialists In Endodontics
Authors: Ehrmann E.H.
Published: February 2010

A historical review is presented of the growth and development of the MDSc programme in Endodontics at the University of Melbourne.
Root Canal Disinfection: A Review Of Concepts And Recent Developments
Authors: Ørstavik Dag
Published: February 2010

This paper reviews current concepts of root canal infection and the consequences for endodontic treatment strategies and practices. In particular, root canal disinfection by chemical and mechanical means is discussed, as are the possibilities and limitations of proposed methods to reduce the time necessary to obtain a disinfected canal.
Inaugural Geoffrey Heithersay Oration In Endodontics And Oral Biology
Authors: Heithersay Geoffrey S.
Published: February 2010

Smiles are often a reflection of dental health, and as such provide great satisfaction to a dental practitioner who has successfully managed complex dental problems such as malformed, malpositioned or traumatically damaged teeth. A biological approach to the management of the pulpal and periodontal responses to dental trauma has been made possible by cumulative research, and application of this knowledge will enhance successful treatment.
Nickel‐Titanium Rotary Instruments: Current Concepts For Preparing The Root Canal System*
Authors: Ruddle Clifford J.
Published: February 2010

The purpose of this paper is to provide useful information that will enable dentists to predictably shape root canals for three‐dimensional obturation of the root canal system. The information is intended to help clinicians better understand when and how to safely use Nickel‐Titanium (NiTi) rotary shaping instruments. This article is intended to enhance clinical performance for all dentists who perform root canal preparation procedures regardless of which instruments are chosen and the techniques employed during their utilisation. The guidelines for successful access and the concepts and strategies for canal preparation are discussed. Additionally, the advantages of negotiating and then pre‐enlarging the coronal two‐thirds of the canal before negotiating and finishing the apical one‐third are emphasised. Although a set of endodontic instruments can shape a root canal, this article will also review the importance of irrigants and their role in cleaning the root canal system.