bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of porcelain material and composite luting resin on microleakage of porcelain laminate veneers
Authors: ZAIMOǦLU A. , KARAAǦAÇIOǦLU L. , ÜÇCTAŞLI  
Published: June 2007

Summary The microleakage beneath porcelain laminate veneers was investigated. The restoration margins were located according to the preparations made below or above CEJ of extracted maxillary central incisors. Vitadur N and Microbond porcelain materials were used to prepare laminate veneers. A light cured composite resin (Porcelite®) and a light‐ and chemical‐cured composite resin (Porcelite Dual Cure®) were used as luting agents. The bonded specimens were thermocycled and by employing the standard dye penetration technique, the leakage was scored from cervical and incisal margins.Significantly greater microleakage was recorded at the dentine composite resin interfaces than at the enamel/composite interfaces. Statistically insignificant differences were observed with the use of the four cement/porcelain combinations studied.
Effects of nickel‐chrome dental alloys used in dentistry on saliva and serum nickel levels, peripheral T‐lymphocytes and some other blood parameters
Authors: ARIKAN A. 
Published: June 2007

Summary Epidemiological investigations have shown that nickel is a potent sensitivity producing agent. However, it is not known if intra‐oral use of nickel‐chrome alloys can cause any sensitization reaction.The purpose of this study was to determine if nickel‐chrome alloys used in dentistry influence nickel levels in saliva and serum and whether there were associated changes of some blood parameters such as lymphocyte, T‐lymphocyte, neutrophil, cosinophil, basophil and monocyte.The study was performed on 10 patients all of whom had no medical and dental history of using nickel containing drugs or restorations. Four unit fixed partial pros‐theses containing 22.97% nickel and 22.65% chrome were constructed and worn by the patients. Blood and unstimulated whole saliva samples were taken from the patients before insertion of the prostheses and then 1 month and 6 months post‐insertion. Hematocrit determinations, total and differential leucocyte count, total T‐lymphocyte counts and serum nickel concentrations were determined from the blood samples and salivary nickel concentrations from the saliva samples.It was found that there were no significant changes in circulating T‐lymphocyte and monocyte population but a decrease was found in circulating eosinophil and an increase in circulating neutrophil and basophil populations.
Effects of ultrasonic instrumentation on microleakage in composite restorations with glass ionomer liners
Authors: ARCORIA C.J. , GONZALEZ J.P. , WITASEK B.A. , WAGNER M. J. 
Published: June 2007

SummaryThe aim of this study was to determine the effect of ultrasonic instrumentation on composite resin restorations lined with glass ionomer cement by measuring the extent of dye penetration at the restoration/tooth interface. Preparations, 2‐0 mm in diameter and 2‐5 mm in depth, were made with a 331 bur in 96 human molar teeth without a bevel. The teeth were restored with glass ionomer eement liners (Shofu) and one of two types of composite resin (Silux® and P‐30®). Half of the samples were ultrasonically instrumented for 10 s. The teeth were immersed in 0‐5% methylene blue dye solution and vertieally sectioned. Mieroleakage was scored visually using a seale of 0 to 4. Statistical comparisons were made with X2 analysis and the Marin‐Whitney U‐test at the F<0.05 level. Microleakage was significantly different between both resin types (P< 0‐001), and between the lined and unlined resins (P< 0‐001) that were instrumented, particularly in the P‐30® restorations. Although P‐30® restorations exhibited much less microleakage than Silux®, the use of a glass ionomer liner did not reliably reduce microleakage in either type of material after instrumentation with an ultrasonic device.
Quantification of noble alloy used in‘porcelain‐fused‐to‐metal’restorations
Authors: SOH G. 
Published: June 2007

SummaryHigh costs of gold alloys used in metal substructures of ceramo‐metal restorations increase the cost of restorative treatment. This study determined the per unit weight of a noble metal alloy used in ceramo‐metal crowns and three‐unit fixed‐partial dentures. Generally, tooth size and extent of the tnetal substructure determined the quantity of alloy used.
A transcranial radiographic examination of the temporal portion of the temporomandibular joint
Authors: KEESLER J.T. , CHRISTENSEN L.V. , DONEGAN S.J. , AUSTIN B.P. 
Published: June 2007

SummaryThe temporomandibular joints of 20 human cadaver heads were examined by means of photography (gross anatomic images) and radiography (lateral oblique transcranial images), using the angle created by a line parallel to the Frankfurt horizontal and a line coinciding with the posterior slope of the most lateral (outermost) portion of the articular tubercle. This lateral eminence angle, made visible through an attached metal wire and a straight stick pin and pertaining to the outermost (zygomatic) portion of the eminentia, was about 45° on both enlarged photographs and enlarged radiographs. There were no significant differences between the photographic and radiographic lateral eminence angles on the right and left sides. A more medially placed angle, yet pertaining to the lateral — and supposedly functional (protrusion) — portion of the glenoid fossa, was about 36° on the right side and 51° on the left side of the radiographic images. There were significant differences between the ipsilateral radio‐graphic lateral and medial eminence angles. A separate decision‐making analysis concluded that lateral oblique transcranial radiography is an effective, reliable, and inexpensive method for detection of bony changes in the lateral portions of the temporomandibular joints.
The oral status of elderly removable partial denture wearers
Authors: DRAKE C. W. , BECK J. D. 
Published: June 2007

SummaryA random sample of 1019 elderly home dwelling persons participated in this study. There were 809 dentate respondents, 28.6% of whom wore removable partial dentures. They were examined for coronal and root caries, gingival recession, pocket depth and loss of gingival attachment. The removable partial dentures were also evaluated. Abutment teeth were found to be more likely to have caries and periodontal disease than all other teeth. Using a manova statistical procedure, the analysis indicated that the partial denture itself, irrespective of any professionally determined problems with the denture, appears to affect coronal and root caries on the teeth of partial denture wearers. Partial dentures judged to need repair or adjustment were related to periodontal status. The data on adverse effects of partial dentures suggest a need for patient education by the dentist and through public health measures, and good oral self care and regular professional recall for people who wear removable partial dentures.
Longitudinal study on forces transmitted from denture base to retainers of lower distal‐extension removable partial dentures with conus crown telescopic system
Authors: OGATA K. , OKUNISHI M. , MIYAKE T. 
Published: June 2007

SummaryThe purpose of this study was to perform longitudinal measurement of forces transmitted from the denture base to retainers of lower distal‐extension removable partial dentures with a conus crown telescopic system. The experimental denture was embedded with a force‐detecting unit which could detect a change in lateral and vertical forces transmitted from denture base to retainers at the same time. Forces were measured during chewing of food on several separate occasions from the insertion of new dentures to about 3 months after. Max.ver (maximal mean value of vertical force) and Max.lat (maximal mean value of lateral force) were calculated from the peak level of all strokes of chewing of food at the minimum of the interocclusal distance.The results are summarized as follows:

There were no significant changes of Max.ver and Max.lat;
There were no significant differences of Max.ver between subjects the value of which was about 20 N;
There were significant differences of Max.lat between subjects the value of which was less than 15 N.
Impact fracture characteristics of intact and crowned human central incisors
Authors: STOKES A.N. , HOOD J.A.A. 
Published: June 2007

SummaryDynamic fracture energies and patterns of fracture in extracted human central incisors were determined for groups of intact controls, groups with Vita Dur N® crowns, Vita Hi Ceram® crowns, Dicor® crowns and porcelain veneers. Teeth were struck on their middle labial surfaces by a pendulum impact device.The mean fracture energy for teeth with Dicor crowns was significantly lower than for all other groups (P<0.05). Control tooth crowns fractured obliquely in an apicaldirection. Vita Dur N® and Dicor® crowns, shattered, the underlying tooth usually fracturing in the plane of the impact force. Vita Hi Ceram® crowns chipped at the site of impact and some fractures were located in the roots. Gold crowns remained cemented and fracture occurred at the crown/root junction, or in the root. Porcelain veneers fractured at the site of impact but remained cemented. Dicor® crowns were less fracture resistant than other restoration types tested. Porcelain veneers and full gold crowns stiffened teeth which led to more root fractures than the porcelain crowns.
The ratio between vertical and horizontal changes of impressions
Authors: LEWINSTEIN I. 
Published: June 2007

SummaryThe purpose of this study was to analyze theoretically and experimentally the relations between the horizontal and the vertical changes of impressions taken with a mandibular stock tray. According to the theoretical analysis the ratio between the horizontal (ΔX) and the vertical changes (ΔX) can be expressed as:
image
where μ is the Poisson's ratio and Lx and Lz are the horizontal and vertical dimensions of the die, respectively. With regard to the experimental findings the Poisson's ratio calculated by this expression was μ=0.44 which fits the range of Poisson's ratio for rubber materials. In addition it was shown that the ratio between the vertical and horizontal strains is constant for a particular impression technique.
Dual‐cure luting composites. Part I: filler particle distribution
Authors: INOKOSHI S. , WILLEMS G. , VAN MEERBEEK B. , LAMBRECHTS P. , BRAEM M. , VANHERLE G. 
Published: June 2007

Fourteen dual‐cure luting composites were analyzed for their filler particle shape, predominant and maximum filler size, and filler weight in function of their clinical use. Polished surfaces were etched with an argon ion beam and studied by means of scanning electron microscopy.The type of filler particles, either inorganic or prepolymerized, could clearly be recognized. Their shapes were angular, rounded or spherical, depending on the product. The maximum filler size varied extremely from less than 1 urn to 250 urn. A particle‐size distribution analyser disclosed a bell‐shaped filler‐size distribution. The predominant filler size for all the products was much smaller than the maximum filler size. The filler weight varied from 36 to 77%. After ion etching, some products showed small areas with a low degree of filler loading. A classification of the luting composites based on the maximum filler size is proposed. Since the particle size varies widely within the group of products analyzed, a standard specification for luting composites is urgently needed.
A method for the estimation of traces of chlorhexidine in water
Authors: WILSON S.J. , WILSON H.J. 
Published: June 2007

A simple method of estimating traces of chlorhexidine in water using bromothymol blue is described. The procedure involves the extraction of the chlorhexidine/bromothymol blue complex into carbon tetrachloride from a buffered neutral solution and measurement of the absorbances of the extracts in a spectrophotometer.The extracted complex has good colour stability, and the method is accurate, reproducible, and very sensitive, with concentrations of chlorhexidine down to 0.05 μg ml‐1 measurable.
Longitudinal study on occlusal force distribution in lower distal‐extension removable partial dentures with conus crown telescopic system
Authors: OGATA K. , ISHII A. , SHIMIZU K. , WATANABE N. 
Published: June 2007

The purpose of this study was to examine longitudinal changes of the occlusal force distribution in lower distal‐extension removable partial dentures with the conus crown telescopic system. Occlusal force applied to the denture and forces transmitted to the retainers were measured on several separate occasions from the insertion of new dentures to about 3 months after. The occlusal force distribution ratio to the retainers was calculated when a load of 20N was applied to the denture.The results are summarized as follows:

The more posterior the loading point of occlusal force, the smaller was the ratio. When the occlusal force was applied to the most anterior artificial tooth, the ratio was 65‐100% of the occlusal force.
As the denture wearing time proceeded, the ratio was decreased. The smaller the ratio, the greater was the rate of its decrease.
A 4‐year clinical evaluation of extensive amalgam restorations — description of the failures
Authors: PLASMANS P.J.J.M. , VAN 'T HOF M.A. 
Published: June 2007

SummaryThe 4‐year evaluation of a randomized controlled clinical trial to the functioning of Extensive Amalgam Restorations (EAR) is reported. In this trial 300 EAR were made by three operators on molar teeth. Five different auxiliary retention methods were used to retain these restorations. In the evaluation a differentiation in ‘absolute’ and ‘relative’ failures was made. After 4 years seven absolute failures (EAR dislodged or removed) were encountered (2%). When relative failures (endodontic treatment or restoration at margin) are also taken into account the number of failures increased to 31 (10%). Due to the low number of failures, no significant influences from experimental variables (c.q. retention method or operator) could be detected. It may be concluded that the results of this interim analysis of the clinical functioning of EAR are promising. It is thought that careful evaluation of cusp strength and reducing weak cusps diminishes clinical failure and as a result, it is not necessary to protect an EAR with a cast restoration in the first 4 years of its clinical life.
Effects of post‐curing by heat on the mechanical properties of visible‐light cured inlay composites
Authors: KHAN A.M. , SATOU N. , SHINTANI H. , TAIRA M. , WAKASA K. , YAMAKI M. 
Published: June 2007

SummaryThe aim of this study was to evaluate the effects of post‐curing by heat on the mechanical properties of visible‐light (V‐L) cured three inlay composites and three posterior filling composites. One group was only photo‐cured according to the manufacturers' recommended methods, while the other group was heat‐treated at 100°C for 15 min following initial cure by V‐L. Knoop hardness, diametral tensile strength and compressive strength were measured to evaluate the mechanical properties. Cure performance was checked out by the solvent immersion test. Upon secondary‐curing by heat, it was confirmed that the mechanical properties of the composites were increased moderately and the cure performance of the composites was also improved.
Processing dentures using a microwave technique
Authors: ILBAY S.G. , GÜVENER S. , ALKUMRU H. N. 
Published: June 2007

SummaryIn this research the technique of curing denture base acrylic resins by microwave energy was investigated with respect to polymerization method, hardness, mechanical and physical properties. Twenty‐one different polymerization methods were used by varying radiation power and curing time. The Vickers hardness test was applied to the samples which were polymerized. The average value was found to be 22.46 VHN (Vicker hardness number), that is, almost the same as conventionally cured acrylic. The recommended polymerization method of curing acrylic was 3min at 550 W in a microwave oven. Mechanical and physical tests were applied to the samples which were cured by the recommended polymerization method. The average transverse load to fracture value was found to be 7.6 kg, and the transverse deflection value was 1.5 mm at 3500g, and 2.9mm at 5000g. Water sorption of acrylic resin cured by microwave energy was 0.72mg cm−2 and the solubility rate in water was 0.038 mg cm−2. Results conformed with the ADA specification.The findings showed that acrylic resin cured by microwave energy is more resistant to mechanical failure than conventionally cured acrylic and this technique can safely be applied to the production of denture bases.
Occlusion and craniomandibular function among patients treated with removable partial dentures
Authors: MÄHÖNEN K.T. , VIRTANEN K.K. 
Published: June 2007

SummaryForty patients treated with removable partial dentures (RPDs) at the Institute of Dentistry, University of Oulu, were selected for this study. The type of occlusion, horizontal and vertical overlap, the slide between retruded contact position and intercuspal position, and the occlusal interferences were investigated as occlusal parameters. Helkimo's anamnestic and clinical indices were used to measure the craniomandibular function and the clinical index score was used to compare the differences between different groups.The RPD‐generated occlusal interferences seemed to cause most harmful effects in point centric, interference free occlusions, when the damage was directed at the temporomandibular joint. These interferences were most frequently found in the retruded contact position and caused by the RPD teeth.
Objective evaluation for bite plate therapy in patients with myofascial pain dysfunction syndrome
Authors: KOTANI H. , ABEKURA H. , HAMADA T. 
Published: June 2007

SummaryAn electromyographic study of the masseter and anterior temporal muscles together with questioning patients regarding subjective symptoms was performed on 15 patients with myofascial pain dysfunction (MPD) syndrome prior to and during bite plate therapy.The electromyographic study was evaluated by the slopes of the voltage tension (V/T) curves (calculated as the value of the relative inclination between the integrated electromyram and the biting force). The improvement of subjective symptoms was recognized earlier than the relief of objective symptoms by bite plate therapy. The results confirm that judgement of level of improvement following treatment of MPD syndrome is more appropriate through objective evaluation. Follow‐up recording of the voltage tension can be considered to be an objective indicator for patients with MPD syndrome.
Interexaminer reliability of six orthopaedic tests in diagnostic subgroups of craniomandibular disorders
Authors: LOBBEZOO‐SCHOLTE A.M. , DE WIJER A. , STEENKS M.H. , BOSMAN F. 
Published: June 2007

SummaryInterexaminer reliability is defined as the degree of consistency among examiners when making observations of the same clinical variable. In the present study, the interexaminer reliability of six orthopaedic tests was determined in a group of 79 patients with signs and/or symptoms of craniomandibular disorders (CMD), subdivided into three subgroups of patients with a mainly myogenous, a mainly arthrogenous, and a combined myogenous and arthrogenous disorder. Multi‐test scores were composed for each test and combinations of tests for the three main symptoms of CMD, viz. pain, joint noises and restriction of movement. Although the orthopaedic tests showed different reliability scores, overall reliability of the determination of these three main symptoms of CMD was satisfactory.In the subgroups, arthrogenous signs and symptoms could be determined reliably with the set of six tests, whereas the reliability of the tests in determining pain and joint noises in the myogenous group was rather low. It may be concluded that the tests are well suited to evaluate arthrogenous signs and symptoms, but that the clinician should be aware of erroneous results of the tests in evaluating pain of a myogenous origin.
Histological and immunohistochemical studies on the articular cartilage after experimental discectomy of the temporomandibular joint in rabbits
Authors: MIYAKI K. , MURAKAMI K. , SEGAMI N. , IIZUKA T. 
Published: June 2007

SummaryTotal discectomy was performed experimentally in the rabbit temporomandibular joint (TMJ). In order to evaluate the injury and repair of the articular cartilage of the mandibular condyle after discectomy, both histologic and immunohistochemical observations were made. Immunohistochemical observation by using bromodeoxyuridine (BrdU) and its monoclonal antibody in vivo labelling method was used.The present study demonstrated that the cartilage on the articular surface of the condyle disappeared at 1 week post‐operatively. This defect in the injured articular cartilage was not repaired by the cartilage, but was covered by a fibrous connective tissue at 6 weeks post‐operatively, where the condylar recontouring by the adjacent articular cartilage, and flattening and hyperplasia of the condyle were observed. Thus, the cartilaginous repair following discectomy was characterized by the proliferation of the adjacent cartilage to the injured site and osteoblastic formation in the bone marrow at the exposed subchondral bone.
Temporomandibular joint osteoarthritis: a comparative clinical and tomographic study pre‐ and post‐treatment
Authors: SATO H. , FUJII T. , YAMADA N. , KITAMORI H. 
Published: June 2007

SummaryNineteen patients with definite and suspected temporomandibular joint (TMJ) osteoarthritis participated in this study. All patients were treated by dental care including bite plane therapy. By comparing the pre‐treatment clinical symptoms and TMJ tomograms with those post‐treatment, efficacy of the dental treatment applied for these patients has been assessed.Since TMJ pain and limitation of mouth opening were considerably improved in almost all patients post‐treatment, this suggests that the clinical prognosis of TMJ osteoarthritis can be favourable. On the other hand, radiographic changes post‐treatment were variable. The longitudinal changes found in the TMJ tomograms were classified into four types. The frequency of Type 2 and Type 3, which indicate the occurrence of TMJ remodelling during the observation period, was fairy high (20 TMJs and 14 patients).
Effect of polylactic acid on osteoinduction of demineralized bone: preliminary study of the usefulness of polylactic acid as a carrier of bone morphogenetic protein
Authors: SAITOH H. , TAKATA T. , NIKAI H. , SHINTANI H. , HYON S.‐H. , IKADA Y. 
Published: June 2007

SummaryTo evaluate the usefulness of polylactic acid (PLA), a bioabsorbable and plastic polymer, as a carrier of bone morphogenetic protein (BMP), a preliminary study has been carried out to investigate any negative effect of PLA on osteoinduction of demineralized bone (DB). PLA (10,600mol. wt) was mixed with DB particles (1– 1.5 mm square) prepared from rat femurs and laid subcutaneously on the intercostal muscle of 4‐week‐old Wistar rats. The PLA/DB pellets were harvested at 2, 4, 8 and 24 weeks after the operation, and prepared for light microscopic examination. Histological examination revealed cartilage formation at 2 weeks and new bone formation at 4 weeks. Extensive bone and marrow formation were observed at 24 weeks. PLA was gradually absorbed and completely disappeared at 24 weeks to be replaced by connective tissue. These results demonstrate that PLA does not have a negative influence on the osteoinductive activity and that PLA could well be a promising bioabsorbable carrier of BMP.