bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pressures recorded at the denture base–mucosal surface interface in complete denture wearers
Authors: WATSON C. J. , HUGGETT R. 
Published: June 2007

SummaryThis study reports on pressures recorded at the denture base–mucosal surface interface in four edentulous subjects. Four sites were selected, namely (a) the mid‐palatal region in the upper complete denture, (b) the labial to the mid‐line lower complete denture, (c) directly under the lower left and (d) right first molar teeth.The study examined the reproducibility of the pressure values obtained when the subjects chewed two test foods (carrot and peanut). The subjects repeated the chewing sequences on the same day and one subject was tested over a 3‐day period. The younger subjects and subjects with the shortest chewing sequences gave the most reproducible results. The two foods were shown to have different effects both on the pressure values recorded and the duration of the chewing sequence. Patients who transferred the food bolus from side to side during the chewing sequence affected the reproducibility of the results obtained from the lower denture transducers.
Dental stability and maximal masticatory muscle activity
Authors: JIMÉNEZ I. D. 
Published: June 2007

SummaryThe electromyographical (EMG) activity of masticatory muscles during full clenching in the retruded contact position (RCP) and intercuspal position (IP) with and without a posterior stabilizing splint was studied. The linear envelope EMG signal from three bilateral muscles was recorded (masseter, anterior temporal and posterior temporal). Thirty‐seven subjects were evaluated. Clenching in the RCP without the splint and with the presence of an unstable occlusal contact inhibited the masseter muscle activity and reduced anterior temporal and posterior temporal muscle activity. The masticatory muscle activity returned to normal when clenching in the RCP with a splint that permitted stability in the dentition. EMG activity was the same in the IP with and without the splint.The results indicate that the determinant of maximal masseter isometric muscle contraction is the amount of stability in the dentition rather than the jaw position. If the dentition takes the major role of stabilizing the mandible, i.e., there is good intercuspation, the masseter muscle can exert maximal isometric contraction. If the stability is not provided by the dentition, i.e., there is a premature contact, the jaw muscles must contribute to the stabilization and reduce the magnitude of the maximal contraction to avoid damage to the structures involved in the compensatory stabilization.
Forces required by complete dentures for penetrating food in simulated function
Authors: EERIKÄINEN E. , KÖNÖNEN M. 
Published: June 2007

SummaryForces required by complete dentures for penetrating some commonly used food items were measured experimentally. These forces were compared with the maximal bite forces of twenty‐seven complete denture wearers.Food items that required the greatest forces in direct closure were rye bread (167 N), raw carrot (118 N), boiled meat (80 N), and raw cabbage (74 N). Raw carrot and raw cabbage required the greatest force in straight incision (39 N and 33 N, respectively). Simulated laterotrusion aided most in the penetration of rye bread and boiled meat. The penetration forces in simulated conditions were high compared with the maximal bite forces of the complete denture wearers.
Chemomechanical caries removal—a clinical evaluation
Authors: ZINCK J. H. , McINNES‐LEDOUX P. , CAPDEBOSCQ C. , WEINBERG R. 
Published: June 2007

SummaryThe aim of this investigation was to evaluate the efficacy and convenience of decayed dentine removal with N‐monochloro‐DL‐2 aminobutyrate (CARIDEX) in all classes of cavities. Fifty‐seven patients, each with two teeth having similarly sized carious cavities, participated in this study. One cavity in each patient was treated with the chemomechanical CARIDEX technique and the other cavity was treated with conventional mechanical drilling. The cavities were restored with either amalgam, composite or glass ionomer restorative materials. The time taken for access and caries removal was noted and the efficacy of caries removal with each technique was evaluated. The chemomechanical caries removal technique was effective in removing 90–100% of decayed dentine in 98% of the cavities treated. Multiple regression adjusted access and caries removal time to account for volume of caries removed. This adjusted time was operator dependent, and ranged from 4 to 10 minutes longer for CARIDEX than for the conventional technique. Ninety‐three per cent of patients preferred the chemomechanical method of caries removal over the conventional technique (highly significant P<0·001). Even though the chemomechanical removal of caries is slower than the conventional technique, the efficacy of CARIDEX and its high patient acceptance provides a viable alternative method for dentinal caries removal in all classes of cavities.
Single‐crystal sapphire endosseous dental implant loaded with functional stress—clinical and histological evaluation of peri‐implant tissues
Authors: HASHIMOTO M. , AKAGAWA Y. , NIKAI H. , TSURU H. 
Published: June 2007

SummaryPeri‐implant tissues of the single‐crystal sapphire implant connected with neighbouring teeth by a metal bridge‐work were examined clinically, radiographically, and histologically in ten monkeys. Professional tooth cleaning was performed during the study. At 3–12 months after insertion, most of the implants were firmly connected to the surrounding tissues and peri‐implant gingiva was regarded as healthy, based on various periodontal parameter scores. Destructive changes of the peri‐implant bone were not found radiographically. Histologically peri‐implant gingiva was revealed to show similar structure to that of the gingiva around natural teeth. Direct bone‐implant interface was observed at 3 months after insertion, while a thin loose fibrous connective tissue layer was present between bone and implant at 6 and 12 months. Such different interrelationship between bone and implant might be attributable to the difference in distribution of functional stress.
Bilabial compression force discrimination by human subjects
Authors: WILLIAMS W. N. , VAUGHN A. O. , CORNELL C. E. 
Published: June 2007

SummaryThis study examined and compared bilabial compression force difference limen (DL) values (the minimally perceivable difference between two compression forces) for a group of twenty normal‐speaking female subjects (mean age, 25 years) under conditions with and without the teeth clenched. In addition, measures of maximum bilabial compression force under conditions with and without the teeth clenched were obtained. Mean DL values obtained against a standard of 100 gm were 36 gm for the clenched condition and 38 gm with no clenching. Discrimination performance under these two conditions was not significantly different (P>0.05). Mean maximum bilabial compression force was 411 gm with the teeth clenched and 568 gm without clenching. This difference in performance was significant (P<0.01). This study provides initial normal data against which individuals with labial sensorimotor dysfunction can be compared.
A new objective parameter for the electromyographic evaluation of masticatory function of edentulous patients
Authors: NAGASAWA T. , YOSHIDA K. , MINAGI S. , TAMURA H. , TSURU H. 
Published: June 2007

SummaryAn objective parameter for the electromyographic evaluation of the masticatory function of edentulous patients was studied. The normal ranges of the parameters for such subjects were also established.This study focused on the time parameter of electromyography, which is one of the most reproducible parameters. The variation coefficient of the time parameters (interval and duration) were revealed to be reliable and reproducible for the evaluation of masticatory functions.
Pain in the sternocleidomastoid muscle and occlusal interferences
Authors: KOHNO S. , YOSHIDA K. , KOBAYASHI H. 
Published: June 2007

SummaryThe EMG of the sternocleidomastoid muscle and the masticatory muscles during function has been observed in relation to opposing occlusal contacts. The purpose was to investigate the possible developmental mechanism of pain which can occur in the muscles.Six subjects with normal function and ten patients were studied. EMG activities of temporal, masseter, sternocleidomastoid (insertion) and sternocleidomastoid (middle) were recorded by surface and needle electrodes.EMG activity was recorded from the insertion of the sternocleidomastoid during activity of the masticatory muscles in tapping, clenching, and mastication. On the other hand little activity was registered from the middle of the sternocleidomastoid. The amplitude of the EMG of SCM‐I increased as the occlusal force increased. During chewing the sternocleidomastoid muscle was functioning more actively on the working side than on the non‐working side. On the patients, EMG activities of the muscles were of low amplitude and low frequency with no synchronization with the chewing movement, suggesting hyperactivity of the muscle.
Lateral forces exerted on the abutment tooth of complete mandibular overdentures
Authors: OGATA K. , NISHIGAWA G. , AOKI T. , MAEDA Y. , OKUNO Y. 
Published: June 2007

SummaryThe purpose of this study was to analyse the magnitude and direction of lateral forces exerted on the abutment tooth of a complete mandibular overdenture. A newly developed transducer was used for measuring forces. It was small enough to be embedded in the lower denture base, and could detect the magnitude and direction of forces.Five subjects, 38 to 77 years of age, with an edentulous maxilla and one or two canines remaining in the mandible were selected for this experiment. An upper complete denture and a lower complete overdenture with only one abutment tooth were fabricated for each subject. Forces exerted on the abutment tooth were measured during tapping and chewing of kamaboko (a Japanese cooked fish paste with soft consistency) and also peanuts, a few days and about 20 days after the denture insertion.The following results were obtained: (i) the average magnitude of lateral forces ranged from 0.5 to 2.0 kgf, and there were significant differences of the mean value between subjects; (ii) lateral forces were mainly observed on an imaginary line drawn through the experimental tooth (lower canine) and the opposite retromolar pad. There were no significant differences between the first and the second measurement.
Dentine hypersensitivity. I. Effects produced by the uptake in vitro of metal ions, fluoride and formaldehyde onto dentine
Authors: ADDY M. , MOSTAFA P. 
Published: June 2007

SummaryDentine has been shown to possess affinity for a large number of varied compounds, many of which have been shown effective in clinical trials, for the treatment of dentine hypersensitivity. The mode of action of these compounds is unclear. The aim of this study was to investigate the uptake of metal ions, fluoride and formaldehyde in solution onto dentine in vitro and determine whether therapeutic effects could be mediated through occlusion of dentinal tubules. Etched dentine sections were exposed for 1 h to 1000 ppm solutions of fluoride and metal salts. Levels of fluoride and respective metals could be extracted and measured from the specimens. Saliva pretreatment had a variable but small effect on uptake of each ion, but post treatment washings reduced all levels of retained fluoride and metals. X‐ray micro‐analysis indicated surface or immediate subsurface deposits of metals. However, surface changes were only consistently produced by zinc and more particularly tin salts. Both zinc and tin salts produced covering or obturation of tubules. The surface effects of zinc could largely be reversed by washing, but not those of tin. Formaldehyde alone or in the presence of saliva produced no effects. A 4‐week study involving twice daily exposure of specimens to saliva and fluoride, metals or formaldehyde yielded essentially the same results. It is unlikely that, except for tin, the compounds tested achieve their apparent clinical effects mediated by direct occlusion of dentinal tubules.
Simple methods for denture identification: a clinical trial
Authors: HEATH J. R. , ZOITOPOULOS L. , GRIFFITHS C. 
Published: June 2007

SummaryThe persistence of identification marks applied to dentures with two‐spirit solvent based fibre tip pens and graphite pencil covered with an experimental and a proprietary sealant were studied under service conditions. In general, the marks applied with the pens were rapidly lost, but those covered with the sealants persisted satisfactorily. The experimental sealant performed slightly better than the proprietary product.
Investigation of the aetiopathogenesis of amelogenesis imperfecta through microscopic, submicroscopic and cytogenetic methods—a case report
Authors: KORAY F. , SOYMAN M. , ERDOǦAN G. 
Published: June 2007

SummaryA case of hypomineralized type of amelogenesis imperfecta has been evaluated by using microscopic, submicroscopic and cytogenetic techniques. It has been observed that some of the enamel contained hydroxyapatite crystals and showed normal mineralization, but some others consisted of transparent, crystal plates of octacalcium phosphate, revealing that these enamel prisms have hypomature characteristics. Extra chromosomes which belong to D‐autosomes were found in the culture obtained from the peripheral blood of the patient, suggesting that the patient has 15% hyperdiploids. It is suggested that the structural disorders in some of the enamel prisms resulted from alterations in the environmental conditions related to chromosome anomalies.
Effect of elimination of occlusal interferences on signs and symptoms of craniomandibular disorder in young adults
Authors: KIRVESKARI P. , LE BELL Y. , SALONEN M. , FORSSELL H. , GRANS L. 
Published: June 2007

SummarySixty‐two dental students judged not to be in need of treatment for craniomandibular disorder (CMD) were randomly divided into two groups, one receiving occlusal adjustment and the other mock adjustment. A double‐blind study design was applied. After 2 years of education in dentistry, including courses in stomatognathic physiology, the increase in the subjective symptoms of CMD was significantly greater in the placebo control group than in the treatment group. The difference between the groups in the increase of sites tender to palpation was less clear, showing only a trend. However, the increase was statistically significant within the placebo group but not within the treatment group. Prophylactic occlusal adjustment thus appears to be effective in reducing the occurrence of symptoms of CMD, and possibly also the occurrence of clinical signs.
Dentine hypersensitivity. II. Effects produced by the uptake in vitro of toothpastes onto dentine
Authors: ADDY M. , MOSTAFA P. 
Published: June 2007

SummaryToothpastes arguably are the most common preparations used in the treatment of dentine hypersensitivity. Evidence for efficacy largely comes from clinical trials, and supports the role of the contained so‐called “active” ingredient. How such compounds produce therapeutic benefit has received limited attention. This study measured the availability and uptake onto dentine of fluoride and metal ions contained in commercial and test toothpastes. The effects of exposure of dentine sections to these toothpastes, and abrasive only pastes in particular, was investigated by scanning electron microscopy and X‐ray microanalysis. Aqueous extracts of the different toothpastes contained measurable concentrations of the incorporated metal and or fluoride, but usually considerably below that incorporated by the manufacturer. Extraction of dentine sections exposed to toothpaste slurries revealed levels of fluoride and metal ions, although post‐treatment washing in water reduced these levels. Surface changes at 1 and 10 h were not consistent with the uptake of fluoride or metals. These changes were almost certainly produced by the contained abrasives, including calcium carbonate, dicalcium phosphate, alumina and silica. In particular fume silica progressively accumulated on the dentine surface to narrow and occlude dentinal tubules. Unlike other abrasives fume silica was resistant to removal by washing. It would appear that insufficient attention has been given to the therapeutic potential of toothpaste ingredients, particularly abrasives, to produce benefit by occlusion of dentinal tubules.
Water sorption and solubility of resin‐based materials following inadequate polymerization by a visible‐light curing system
Authors: PEARSON G. J. , LONGMAN C. M. 
Published: June 2007

SummaryThe water sorption and solubility of three hybrid and one microfine composite are reported. The values obtained are dependent on composite type and resin system. Incomplete polymerization of the two materials resulted in increased solubility and sorption due to incomplete conversion of the monomer. The marked increase in both parameters will have clinical significance on the durability of the material.
Wearing of removable partial dentures in relation to periodontal pockets
Authors: TUOMINEN R. , RANTA K. , PAUNIO I. 
Published: June 2007

SummaryUsing a representative sample of 5028 dentulous Finnish adults the occurrence of periodontal pockets was studied separately for the maxillae and the mandibles among removable partial denture (RPD) wearers and non‐wearers. RPD(s) were worn in 11.2% of the 3444 maxillae with at least four natural teeth remaining, and in 7.7% of the 4706 corresponding mandibles (P<0.001). Periodontal pockets were more frequently observed in maxillae than mandibles. Wearing of RPDs highly significantly (P<0.0001) increased the odds of having periodontal pockets in general (4 mm or more) as well as the odds of having deeper periodontal pockets (exceeding 6 mm). This phenomenon was observed both in the maxillae and in the mandibles. These results suggest that wearing of RPD is a threat to periodontal tissues and that dentists should take care to frequently recall their patients fitted with RPD(s). During the recall visits more attention should be paid to the periodontal conditions of patients wearing RPD(s).
Physical properties of two new crown and bridge veneering resins
Authors: GREENER E. , DUKE S. 
Published: June 2007

SummaryThe degree of conversion and physical properties of two contemporary resin veneers based on light‐cured microfilled composite formulations and employing proprietary curing systems were evaluated. Visio‐gem (V) and Dentacolor (D) were polymerized using the appropriate curing systems. Polymer structure and degree of conversion were determined by Fourier transform infra‐red (FTIR) techniques. Physical properties, including depth of cure, compressive and diametral tensile strengths, hardness, thermal expansion and colour stability were determined by standard test modalities. Both materials appear to have the properties of typical microfilled resins including low compressive yield strengths and high thermal expansion coefficients. The curing system for V produced an increased depth of cure compared to conventional light curing techniques and the D system, but no clinically significant increase in the physical properties.
Comparative electromyographic study of elevator muscles in patients with complete dentures and natural dentition
Authors: MIRALLES R. , BERGER B. , IDE W. , MANNS A. , BULL R. , CARVAJAL A. 
Published: June 2007

SummaryAn analysis of integrated electromyographic (IEMG) activity of masseter and anterior temporal muscles was undertaken in fifteen patients with complete dentures and eight adult subjects with natural dentition.Bipolar surface electrodes were used for IEMG recordings during maximal voluntary clenching and saliva swallowing in the inter‐cuspal position.The IEMG activity of both muscles during maximal voluntary clenching was significantly lower in patients with complete dentures than in subjects with natural dentition. During saliva swallowing the activity in both muscles was similar in both groups. This may have a great clinical significance in the maintenance of the functional state of the different structures of the stomatognathic system in complete denture wearers, since the process of swallowing is a 24‐h function repeated about 600–2400 times each day.
The determination of the electrical potential of a metallic restoration in the oral cavity
Authors: MULLER A. W. J. , DE GROOT D. A. J. , DAVIDSON C. L. 
Published: June 2007

SummaryAn improved method for measuring the electrical potential of a metallic restoration is proposed and tested. Care was taken to avoid disturbing the restoration surface, hence it was not cleaned or dried. The probe tip was a gold‐plated pin, insulated from the saliva by soft wax. The probe was pressed through the wax on to the restoration just before measurement. An Ag/AgCl reference electrode was in contact with the saliva. The probe and the tip of the reference electrode were disposable.
A comparative study of the bond strengths of amalgam and alloy–glass ionomer cores
Authors: ARCORIA C. J. , DE WALD J. P. , MOODY C. R. , FERRACANE J. L. 
Published: June 2007

SummaryThe purpose of this study was to compare the bond strengths of dental amalgam cores and dental alloy‐glass ionomer cores that were luted to cast gold crowns with glass ionomer cement. Seventy‐two human extracted molars were sectioned horizontally and four regular thread mate system pins were inserted into a flat pulpal floor. The teeth were restored with amalgam or alloy‐glass ionomer admixture and prepared for crown preparations. Castings were produced with type III gold and cemented to the cores with Fuji type I glass ionomer cement. Thirty‐six of the specimens were subjected to thermal fatigue by cycling between 4 and 50°C for periods of 1, 5 and 10 weeks. The remainder of the specimens were retained in deionized water at 37°C. Bond strengths of the cores, in tension, were measured with a universal testing machine. The alloy‐glass ionomer cores exhibited higher bond strengths than the amalgam cores for virtually all time periods, particularly the thermocycled samples. The alloy‐glass ionomer cores exclusively displayed core fractures and pin/tooth insufficiencies while the amalgam cores failed because of a deterioration of the glass ionomer luting cement.
Balance in masticatory muscle activity during natural chewing and submaximal clenching
Authors: McCARROLL R. S. , NAEIJE M. , HANSSON T. L. 
Published: June 2007

SummaryThe balance in the electromyographic (EMG) activities of the left and the right masseter and the left and right anterior temporal muscles during chewing and during submaximal clenching at 10% and 50% of the maximum voluntary contraction in the inter‐cuspal position was investigated in twenty healthy adults. Muscular asymmetry patterns during chewing and clenching were positively correlated for both pairs of masticatory muscles investigated at the 50% level (P<0.01‐P<0.001) and for the masseter muscles, also at the 10% level (P<0.01). Stronger correlations in muscular asymmetry were found for the masseter muscles and at the higher submaximal clenching level. In general, the masseter muscles displayed a greater degree of asymmetric activity than the anterior temporal muscles during both chewing and clenching (0.05<P<0.1−P<0.025). The average EMG amplitudes of both masseter or both anterior temporal muscles within each subject showed no correlation between clenching and chewing. The correlations between muscular asymmetries observed during static (clenching) and dynamic (chewing) conditions suggest that there are common factors influencing these activities.