bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification Of Second Canals In The Mesiobuccal Root Of Maxillary First And Second Molars Using Magnifying Loupes Or An Operating Microscope
Authors: Schwarze T. , Baethge C. , Stecher T. , Geurtsen W. 
Published: February 2010

AbstractVarious authors have investigated the frequency of second canals (MB2) in the mesiobuccal roots of maxillary molars, predominantly first molars. Further, it has been reported that the percentage of MB2 canals that are treated during routine endodontic therapy is much lower than the number of second canals identified in vitro.It was the purpose of this study to investigate whether the use of an operating microscope may improve the diagnosis of MB2 canals in mesiobuccal roots of maxillary molars. The canal orifices of 100 maxillary first and second molars (50 of each) were initially inspected by Examiner I using individually‐adapted ×2 magnifying loupes. Subsequently, all teeth were examined by a second investigator using an operating microscope (OPM) with ×8 magnification. Finally, the mesiobuccal roots of all teeth were separated. Then, the sections were analysed histologically and by SEM. The histological investigation revealed a total number of 63 MB2 canals, 39 in first, and 24 in second molars. Only 26 (41.3%) of those canals were identified using magnifying loupes, whereas 59 (93.7%) were found by means of an operating microscope.
Behaviour Of Hero NiTi Instruments Used By An Experienced Operator Under Access Limitations
Authors: Yared G.M. 
Published: February 2010

AbstractThe purpose of this study was to evaluate the failure incidence of Hero 642 nickel‐titanium (NiTi) rotary instruments (HRI) when used by an experienced operator in conjunction with different motors and under limitations of access. HRI were used by an experienced operator in a crown‐down technique. The teeth were mounted in resin arches of a phantom head to reproduce limitations of access. In Groups 1, 2, 3 and 4, air, high torque control, low torque control and very low torque control motors were used respectively. Each group included 30 canals in extracted human molars. One set of HRI was used for each canal; the HRI were sterilised before each case. A 2.5% NaOCl solution was used as an irrigant. An experienced operator performed all the cleaning and shaping procedures after application of a rubber dam. The opening of the mouth in the phantom head was standardised for the four groups. Instrument fracture did not occur in any of the groups. The air, high torque control and low torque control motors were as safe as the very low torque control motor when HRI were used by an experienced operator in a crown‐down manner at 300 rpm.
The Mechanism Of Pulpal Wound Healing
Authors: Tjäderhane Leo 
Published: February 2010

AbstractThe favourable response of exposed pulp tissue against a variety of materials used for pulp capping in experimental conditions, as observed by hard tissue (reparative dentine) formation, demonstrates an intrinsic capacity of pulp tissue for healing. However, in the clinical situation, in which a pulpal exposure is usually accompanied by a long‐term external irritation with the subsequent long‐term inflammatory response to that irritation, the outcome of pulp capping procedures is not as predictable. While some of the factors related to the defensive reactions and healing after pulp exposure and capping procedures are well understood, the mechanisms and importance of others remain less well‐known. Understanding the mechanisms regulating the spread of inflammation and necrosis in pulp tissue, and the factors regulating healing after closure of the wound, would facilitate the development of new and better treatment procedures with more predictable outcomes. In this review, some of the aspects considered to be important in pulpal wound healing are discussed.
Clinical Aspects Of Pulpal‐Periodontal Lesions
Authors: Selxas F.H. , Garrido A.D.B. , Vieira M.L.S.O. , Pécora J.D. , Saquy PC. , Sousa‐Neto M.D. 
Published: February 2010

AbstractIt is well known that the main purpose of dentistry is to keep teeth in the oral cavity so that they may fulfil their various roles. This case report demonstrates a method to treat a situation involving a pulpal‐periodontal lesion, by using a simple and efficient combined therapy. The clinician can thereby determine the cause of the lesion (pulpal and/or periodontal) and subsequently establish the correct treatment, thus improving the prognosis of the case.
Discuss That The Coronal Seal Is More Important Than The Apical Seal For Endodontic Success
Authors: Sritharan Anjella 
Published: February 2010

AbstractOne of the main principles for successful root canal treatment is the prevention of microorganisms and toxins from the oral flora penetrating through the root canal system into the periapical tissues (1). This is achieved by obturating the root canal system completely, including the coronal and apical ends. Inadequate obturation of the root canal system has been found to be the most frequent cause of failure after endodontic treatment (2). A number of studies have indicated that leakage, whether from a coronal or apical direction, adversely affects the success of root canal treatment (3–7). The significance of the coronal seal has been increasingly recognized in the dental literature (4, 5, 8, 9) and in more recent times, it has been suggested that apical leakage may not be the most important factor leading to the failure of endodontic treatment — but that coronal leakage is far more likely to be the major determinant of clinical success or failure (10). This paper will discuss aspects of: endodontic success and failure; the use of leakage studies to assess the quality of the seal; the significance of both apical and coronal leakage; followed by a review of the literature.
Pulp Biology: Progress During The Past 25 Years
Authors: Trowbridge Henry O. 
Published: February 2010

ABSTRACTDuring the past 25 years there has been a rapid expansion in our knowledge of the dentine and pulp complex. This paper provides representative examples of important advances that researchers have made in this field. Topics to be considered include: differentiation of odontoblasts, dentine matrix proteins, extent of odontoblast processes, pulpal stem cells, apoptosis, interstitial fluid pressure in normal and inflamed pulps, class II antigen‐presenting cells of the pulp, cytokines, antibodies, pulpal calcifications, tertiary dentine and pulpal inflammation associated with bacterial contamination of exposed dentine beneath restorations.
Effective Cleaning Protocols For Rotary Nickel‐Titanium Files
Authors: Parashos Peter , Linsuwanont Pairoj , Messer Harold H. 
Published: February 2010

ABSTRACTCleaning of dental instruments before sterilisation is an essential part of processing for re‐use. Rotary nickel‐titanium (NiTi) files as obtained from the manufacturer are mostly not sterile and require cleaning and sterilisation both before first use and for re‐use. We describe here two simple, practical cleaning protocols that are effective in removing organic debris from files. Rotary NiTi files can be safely re‐used from an infection control perspective.
An In Vitro Study Of Coronal Microleakage In Endodontically‐Treated Teeth Restored With Posts
Authors: Ravanshad Shohreh , Ghoreeshi Nemat 
Published: February 2010

AbstractCoronal microleakage has received considerable attention as a factor related to failure of endodontic treatment and much emphasis is placed on the quality of the final restoration. Posts are frequently used for the retention of coronal restorations. These can be custom‐made or prefabricated. Many authors have examined coronal microleakage with respect to gutta‐percha root fillings and plastic coronal restorations, but few have investigated the coronal seal afforded by various post systems. The seal provided by a cemented post depends on the seal of the cement used. The purpose of this study was to compare coronal microleakage around cast and prefabricated posts using a dye‐penetration method. Sixty extracted single‐rooted human teeth were chemomechanically prepared. The root canals were filled with gutta‐percha and sealer and they were then prepared for standard posts. Six groups, each of 10 teeth, were restored with either cast post or prefrabricated post. The posts were cemented with either glass ionomer cement (GIC), Variolink II or Durelon. The teeth were thermocycled and placed in Indian ink for one week. They were then demineralised and rendered transparent. Linear coronal dye penetration around the post was measured and compared. The least dye‐penetration was observed in roots restored with a cast post and Variolink II. Dentatus posts demonstrated the most microleakage. It appears that the dentine‐bonding cements have less microleakage than the traditional, non‐dentine‐bonding cements and adaptation of the post with the canal may be more important than the cement used.
The Influence Of Filling Technique On Depth Of Tubule Penetration By Root Canal Sealer: A Study Using Light Microscopy And Digital Image Processing
Authors: De Deus Gustavo A. , Gurgel‐Filho Eduardo Diogo , Maniglia‐Ferreira Cláudio , Coulinho‐Filho Tauby 
Published: February 2010

AbstractThe purpose of this study was to compare the depth of sealer penetration into dentinal tubules by three root‐filling techniques using light microscopy and digital image processing. Thirty‐two maxillary central incisors were prepared. Two teeth were separated for the control group. The rest were divided into three equal groups and obturated as following — G1: lateral condensation; G2: warm vertical compaction of gutta‐percha and G3: Thermafil system. Each sample was sectioned longitudinally and prepared for microscopic analysis. A sequence of photomicrographs with magnifications of ×50, ×200 and ×500 were taken. Through digital image analysis and processing, measurements for each field were obtained. A non‐parametric ANOVA Kruskal‐Wallis analysis was used to determine whether there were significant differences among the groups. Significant differences between G2 and G1 (p = 0.034) and between G3 and G1 (p = 0.021) were identified. There were no significant differences between G2 and G3 (p > 0.05). The results of this research suggest that samples root‐filled by thermoplasticised gutta‐percha techniques lead to deeper penetration of the root canal sealer into the dentinal tubules.
Treatment Planning Dilemmas Resulting From Failed Root Canal Cases
Authors: Peikoff Marshall D. 
Published: February 2010

Endodontics is one of the least forgiving branches of dentistry in terms of treatment success or failure. As a result, re‐treatment has become a significant part of today's endodontic practice.In the past, it was felt that surgical treatment with root‐end filling would result in the highest degree of success. It has been subsequently demonstrated that microorganisms remaining in the root canal system after treatment were the main aetiological factor in post‐treatment disease. Hence, non‐surgical orthograde re‐treatment has become the treatment of choice. While most authors support this method of re‐treatment, some feel the surgical approach is still the best, and others advocate a combination of treatments.While treatment planning may appear to be straightforward, there are many grey areas in actual practice. This paper attempts to show a number of situations where the treatment planning may not be black and white.
Determination Of Root Canal Curvatures Before And After Canal Preparation (Part 1): A Literature Review
Authors: Sonntag D. , Stachniss‐Carp S. , Stachniss V. 
Published: February 2010

AbstractThe continuing development of methods and materials for root canal preparation is resulting in enhanced preparation techniques with only minor alterations to the canal morphology. Improved evaluation methods are required for differentiated assessment of these innovations. One criterion for assessment of the preparation quality of curved root canals is preparation‐induced straightening of the canal.The first canal curvature measurements served to divide teeth into different curvature classes. However, their actual execution represented mere angular measurement rather than root curvature assessment. This purely graphic method lacked precision, nor could it be readily applied to all tooth groups. Further developments of that method resulted in it being applicable to molars and to canals with multiple curvatures.Some years ago, the graphically determined curvature radius was added as a further parameter to measurement of the canal deviation angle, thus permitting a curvature to be correctly described for the first time in geometric and analytic terms. The first mathematically accurate description was presented by Dobó‐Nagy et al. (20), who correctly described the mean canal curvature in a two‐dimensional image in concrete terms by means of fourth‐degree polynomial functions.Recent developments in the application of microcomputed tomography of extracted teeth permit non‐destructive three‐dimensional assessment of root canal configurations. It remains to be seen whether this resource‐intensive form of in vitro examination can assert itself.
Calcium Hydroxide And Zinc Oxide Eugenol As Root Canal Filling Materials In Primary Molars: A Comparative Study
Authors: Damle S. G. , Nadkarni U. M. 
Published: February 2010

AbstractCalcium hydroxide, a material widely used for the treatment of permanent teeth has not been used frequently for endodontic treatment in primary teeth. A comparative evaluation of calcium hydroxide and zinc oxide eugenol used as root canal filling materials in primary molars is presented.
Seasonal Impacts of Solar UV Radiation on Photosynthesis of Phytoplankton Assemblages in the Coastal Waters of the South China Sea
Authors: Wu Yaping , Gao Kunshan , Li Gang , Walter Helbling Eduardo 
Published: February 2010

AbstractWe carried out experiments to evaluate seasonal changes in the impacts of UV radiation (UVR, 280–400 nm) on photosynthetic carbon fixation of phytoplankton assemblages. Surface water samples were obtained in the coastal area of the South China Sea, where chlorophyll a ranged 0.72–3.82 μg L−1. Assimilation numbers (photosynthetic carbon fixation rate per chl a) were significantly higher during summer 2005 than those in spring and winter 2004. The mean values obtained under photosynthetically active radiation (PAR) were 2.83 (spring 2004), 4.35 (winter 2004) and 7.29 μg C (μg chl a)−1 h−1 (summer 2005), respectively. The assimilation numbers under PAR + UVR were 1.58, 2.71 and 5.28 μg C (μg chl a)−1 h−1, for spring, winter and summer, respectively. UVR induced less inhibition of photosynthesis during summer 2005 than during the other seasons, in spite of the higher UVR during summer. The seasonal differences in the productivity and photosynthetic response to UV were mainly due to changes in water temperature, while irradiance and vertical mixing explained >80% of the observed variability. Our data suggest that previous studies in the SCS using UV‐opaque vessels might have overestimated the phytoplankton production by about 80% in spring, 61% in winter and 38% in summer.
Temperature and Solar Radiation Interactions on 3H‐leucine Incorporation by Bacterioplankton in a Subtropical Estuary
Authors: Bullock Avery K. , Jeffrey Wade H. 
Published: February 2010

AbstractAlthough the effects of UV radiation are thought to be temperature independent, the photoinhibition of aquatic bacteria may be temperature dependent owing to enzymatic repair kinetics, an important consideration for climate change analyses. We examined the interactions between temperature and solar radiation in water samples collected from the Blackwater River, Pensacola Bay, and the coastal Gulf of Mexico (Florida) in July 2008. Subsamples were incubated in the dark for 20 h at either the in situ temperature, +5°C from in situ or −5°C from in situ after which they were amended with 3H‐leucine and irradiated in full sunlight at their respective temperatures and compared to samples incubated simultaneously in the dark. Temperature and light significantly affected 3H‐leucine incorporation at all locations and interactive effects between temperature and sunlight were found for Pensacola Bay and the Gulf. Generally, warmer waters reduced photoinhibition. The −5°C treatment was always significantly more inhibited than the +5°C treatment, but the in situ temperature and +5°C and −5°C treatments were not always significantly different. Photoinhibition reduction at warmer temperatures suggests specific effects on photobiology not observed in general cellular activity may be important in determining interactive ecosystem effects of climate change.
Photophysics of Zinc (II) Phthalocyanine Polymer and Gel Formulation
Authors: Rodriguez Myriam E. , Diz Virginia E. , Awruch Josefina , Dicelio Lelia E. 
Published: February 2010

AbstractThe photophysical properties of lipophilic phthalocyanines encapsulated into a polymer and two different gels were studied in order to predict their photosensitizing efficacy in vivo. Photophysical techniques for solid phase were adapted for light dispersing samples. Gel formulation of two tetrasubstituted phthalocyanines, tetra‐t‐butylphthalocyaninato zinc(II) (1), tetrakis(1,1‐dimethyl‐2‐phthalimido)ethylphtalocyaninatozinc(II) (2) and two octasubstituted phthalocyanines, 2,3,9,10,16,17,23,24‐octakis(decyloxy)phthalocyaninatozinc(II) (3) and 2,3,9,10,16,17,23,24‐octakis[(N,N‐dimethylamino)ethylsulfanyl]phthalocyaninatozinc(II) (4) were investigated for their possible use in photodynamic therapy for topical purposes. Supporting the fact that gel formulation improves the photophysical properties of phthalocyanines, singlet molecular oxygen quantum yield (ΦΔ) values for 1–4 zinc(II) phthalocyaninates in Lutrol® F 127‐Cremophor® RH 40 were 0.60, 0.60, 0.20 and 0.26, respectively. Permeation studies showed that no release of phthalocyanines occurs, thus indicating there should be no risk of generalized skin photosensitivity in areas other than the dye‐deposition site.
A Photochemical Study of Diclofenac and Its Major Transformation Products
Authors: Eriksson Johan , Svanfelt Jesper , Kronberg Leif 
Published: February 2010

AbstractThe photolytic transformation of 2‐(2‐(2,6‐dichlorophenylamino)phenyl)acetic acid (diclofenac) and its transformation products (TPs) (8‐chloro‐9H‐carbazol‐1‐yl) acetic acid (Cz1), 2‐(2‐chloro‐phenylamino)‐benzaldehyde (Ald) and (1,4‐dioxo‐4,9‐dihydro‐1H‐carbazol‐8‐yl) acetic acid (Cz4) in aqueous solutions have been studied. The previously unreported TP (Cz4) was isolated by LC and completely characterized by NMR and MS. UV‐absorption spectra of diclofenac and three of its TPs were determined and used to calculate disappearance quantum yields. The dominating transformation pathway of diclofenac occurs via initial formation of Cz1 and proceeds to form mainly (Cz4) over 200 min of UV‐irradiation. A second minor transformation pathway, which yields Ald as the sole product, was observed only under deaerated conditions.
Factors associated with the use of emergency dental care facilities in a French public hospital
Authors: Tramini Paul , Al Qadi Nassar Buthaïna , Valcarcel Jean , Gibert Philippe 
Published: February 2010

ABSTRACTThis study was undertaken to qualitatively analyze patients’ profiles and to identify the sociodemographic and oral health factors associated with emergency visits to the public dental service in Montpellier, France. A cross‐sectional survey was conducted in the dental care service at Montpellier Hospital. Socioeconomic and clinical variables were compared between the patients using the emergency dental care service and those utilizing the general dental services, which were by appointment.An evaluation of the results indicated that younger patients and people from lower socioeconomic groups used the emergency dental service more frequently. Unemployed people (OR = 1.60) and manual workers (OR = 1.86) were also more likely to use this service. The need for treatment of caries was significantly higher in the group that used the emergency service. It appeared that the two groups of patients had different attendance behavior and showed significantly different socioeconomic and oral health status.
Drug‐induced gingival enlargement: Biofilm control and surgical therapy with gallium–aluminum–arsenide (GaAlAs) diode laser—A 2‐year follow‐up
Authors: De Oliveira Guaré Renata , Costa Soraya Carvalho , Baeder Fernando , De Souza Merli Luiz Antonio , Dos Santos Maria Teresa Botti Rodrigues 
Published: February 2010

ABSTRACTDrug‐induced gingival enlargement has been reported in patients treated with various types of anticonvulsant drugs, and is generally associated with the presence of plaque, gingival inflammation, and a genetic predisposition. Effective treatment includes daily oral hygiene and periodic professional prophylaxis. However, in some patients, surgical removal of the gingival tissue overgrowth becomes necessary. The patient in this case report was mentally impaired and had severe drug‐induced gingival enlargement. This report describes the initial protocol, the gingivectomy, and a 2‐year follow‐up. A diode laser was used as an effective and safe method to remove the patient's overgrown gingival tissue.
Access to dental care—parents' and caregivers' views on dental treatment services for people with disabilities
Authors: Prabhu Neeta T. , Nunn June H. , Evans D. J. , Girdler N. M. 
Published: February 2010

ABSTRACTThe goal of this study was to elicit the views of patients or parents/caregivers of patients with disabilities regarding access to dental care. A questionnaire was generated both from interviews with patients/parents/caregivers already treated under sedation or general anesthesia as well as by use of the Delphi technique with other stakeholders. One hundred thirteen patients from across six community dental clinics and one dental hospital were included. Approximately, 38% of the subjects used a general dental practitioner and 35% used the community dental service for their dental care, with only 27% using the hospital dental services. Overall waiting time for an appointment at the secondary care setting was longer than for the primary care clinics. There was a high rate of parent/caregiver satisfaction with dental services and only five patients reported any difficulty with travel and access to clinics. This study highlights the need for a greater investment in education and training to improve skills in the primary dental care sector.
Quantum-State Controlled Chemical Reactions of Ultracold Potassium-Rubidium Molecules
Authors: Ospelkaus S. , Ni K.-K. , Wang D. , de Miranda M. H. G. , Neyenhuis B. , Quéméner G. , Julienne P. S. , Bohn J. L. , Jin D. S. , Ye J. 
Published: February 2010

Colliding in the ColdChemical reactions occur through molecular collisions, which, in turn, are governed by the distributions of energy in each colliding partner. What happens when molecules are cooled so that they no longer have sufficient energy to collide?Ospelkauset al.(p.853; see the Perspective byHutson) explored this question by preparing a laser-cooled sample of potassium rubidium (KRb) diatomics with barely any residual energy in any form (translational, rotational, vibrational, or electronic). By monitoring heat release over time, evidence was gathered for exothermic atom exchange reactivity through quantum mechanical tunneling. As predicted by theory, these reactions were exquisitely sensitive to the molecular states, with rates changing by orders of magnitude on varying minor factors such as nuclear spin orientation.