bluuebunny/crossref_metadata_2025_split huggingface dataset:
The treatment of hypersensitive cervical abrasion cavities using ASPA cement
Authors: LOW T. 
Published: June 2007

SummaryThis study evaluated the usefulness of the alumino‐silicate polyacrylate (ASPA) or glass ionomer cement in the treatment of hypersensitive cervical abrasion cavities.Various methods of treatment of hypersensitive cervical abrasion cavities have been described, and all these methods have their disadvantages. The ASPA cement was used to treat non‐carious hypersensitive cervical abrasion cavities in 189 teeth from fifty‐eight adult patients. The patients were followed‐up for periods ranging from 6–15 months. Of the 189 treated teeth, the ASPA restoration was intact in 163 or 86.2%. Seventeen teeth or 9.0% had partial loss of the restorations and nine or 4.8% had complete loss of restorations. With regard to symptoms, 176 or 93.1% of the treated teeth were no longer sensitive to stimuli from the oral cavity following placement of the ASPA restoration. Of the fifty‐eight patients, fifty‐two or 89.7% were completely relieved of all symptoms. Of the remaining teeth eleven or 5.8% reported a reduction in the severity of the symptoms. Only one patient; with both restorations lost, reported no improvement. No case of pulpal death was recorded, and there was no evidence of caries at the margin of any of the restorations.The results indicate that the method is effective, and it has some distinct advantages over existing methods of treatment of these cavities.
The effects of the incorporation of chlorhexidine acetate on some physical properties of polymerized and plasticized acrylics
Authors: ADDY M. , HANDLEY R. 
Published: June 2007

SummaryThe effects on the water uptake and weight loss of the incorporation of chlorhexidine acetate in heat cured acrylic and an acrylic gel soft liner was determined. Hardness and transverse bend measurement were similarly made for admixtures to heat and cold cured acrylics. Following soaking in water for 87 days the heat cured test specimens demonstrated an initial weight gain followed by a progressive loss, the soft liner test specimens however all showed weight gains. Drying back specimens to constant weight revealed significantly greater weight losses in test compared to control specimens for both the cured acrylic and gel liner. However these weight losses were less than the chlorhexidine content for 5 and 10% admixtures. Hardness and moduli of elasticity measurements were significantly reduced for heat and cold cured acrylics containing chlorhexidine. The property changes observed in the materials would be consistent with the pattern of incorporation of chlorhexidine into the matrix. However, these do not negate the carriage of medicaments in these materials for prolonged delivery within the oral cavity, if employed as rebase or reline materials in existing prostheses.
Mechanical and adhesive properties of a newly developed group of pulp capping and base materials
Authors: NEGM M. M. , COMBE E. C. , GRANT A. A. 
Published: June 2007

SummaryA new group of dental cements for cavity lining and pulp capping is reported. The mechanical and adhesive properties of the cements, which were designated cement I, II and III, were assessed and compared with a commercially available polycarboxylate cement and calcium hydroxide containing material. The experimental cements were mechanically suitable for use as base materials and proved to be adhesive to dentine, especially cement I which gave adhesive bond values comparable to those of the polycarboxylate cement.
An electromyographic and cephalometric study on facial pains and facial morphology in children
Authors: CHRISTENSEN L. V. 
Published: June 2007

SummaryTwelve children, five girls and seven boys with a mean age of 12 years, exercised maximal voluntary tooth clenching until intolerable pains and total subjective exhaustion of at least the right masseter muscle forced the children to stop the isometric muscle exercise; that is, the pain tolerance, or the isometric endurance time, of at least the right masseter muscle was determined in seconds, and it amounted to an average of 100 s. Concomitantly, the electrical activity in the right masseter muscle was recorded by bipolar surface electrodes and integrated, and it showed a significant decrease of 32 % during the endurance test, probably as an expression of progressive physiological muscle fatigue. A large ANB angle was associated with relatively little decline of the contractile activity and a trend not to endure pains, possibly because isometric tension was generated predominantly by muscle fibres with a high anaerobic capacity.
Oral awareness and oral motor proficiency in retchers
Authors: WRIGHT SUSAN M. 
Published: June 2007

SummaryIt has been suggested that hypersensitivity and awareness of dentures are causes of retching associated with dentures and dental treatment. Oral form recognition (OFR) and oral motor (OM) ability were examined in fifty‐three pairs of retchers and controls. The retchers had all had problems with retching when wearing dentures or during dental procedures. The controls were the same sex as the retchers and were matched with them as closely as possible for age, remaining teeth and edentulous spaces.No difference in OFR and OM ability was found between the paired subjects which might indicate that increased oral awareness contributed to the retchers' symptoms.
Structural changes in composite surface material after dry polishing
Authors: DAVIDSON C. L. , DUYSTERS P. P. E. , De LANGE C. , BAUSCH J. R. 
Published: June 2007

SummaryThe purpose of this study was to investigate the properties of composite materials that had been heated to temperatures which may occur during dry polishing. Bulk composite material was submitted to thermal analysis from R.T. to 200°C. Two distinct stages of thermal reaction in this range could be identified. One at approximately 70°C, which could be related to a further initiating of unreacted groups, and one above 100°C, which could be related to the glass transition. The glass transition was also observed microscopically. Hardness measurements were carried out on the warm material at different temperatures as well as on the material being cooled down to R.T. With temperature rise, a continuous increase in hardness and abrasion resistance could be demonstrated. The observed phenomena for bulk material are related to the properties measured on dry polished surfaces.
The role in masseter muscle activities of functionally elicited periodontal afferents from abutment teeth under overdentures
Authors: MUSHIMOTO EIKO 
Published: June 2007

SummaryFive overdenture wearers with a small number of remaining natural teeth were selected to evaluate the effect of the afferent input from periodontal mechanoreceptors on masseter activity in man. As a control, a full denture wearer was included. The subjects were instructed to chew a piece of gum, and/or tap their teeth. Surface EMG from the bilateral masseter muscles were recorded and analysed.When functional pressure was applied, during chewing, to the abutment teeth as well as to mucosa through the denture base, masseter activities were encouraged. Following application of anaesthesia to the periodontal membrane of the abutments, masseter activities were reduced.The duration of the silent period (SP) appearing in the EMG burst following tooth tapping was significantly increased with root support compared to mucosal support only. With topical anaesthesia of the periodontal tissues, SP duration decreased significantly.In conclusion, it has become apparent that the pressure sensibility of abutment teeth bearing functional pressure under an overdenture base is capable of facilitating masseter activity, as one of the sources of oral sensory input during mastication.
Recent results concerning physiological tooth movement and anterior guidance
Authors: SIEBERT G. , Siebert Götz 
Published: June 2007

SummaryPhysiological tooth movements during mandibular excursions with and without occlusion have been considered. Using electronic and pantographic techniques, anterior guidance and tooth movements during simulated mastication (without a bolus) were investigated.Investigations in the absence of occlusion showed that elastic deformation of the mandible gave rise to tooth movements. During occlusion three‐dimensional tooth movements of up to 60 μm in each direction occurred.Pantographic measurements of anterior guidance showed that each type of occlusion (balanced occlusion, group function and canine protected occlusion) has its own characteristic. Only canine protected occlusion gave values which corresponded to physiological data.
The Dentatus screw: comparative stress analysis with other endodontic dowel designs
Authors: STANDLEE J. P. , CAPUTO A. A. , HOLCOMB J. P. 
Published: June 2007

SummaryUsing photoelastic stress analysis, this study shows that the tapered, self‐threading, Dentatus endodontic screw causes severe wedging forces on installation. These stresses are magnified by increases in dowel diameter and the application of occlusal loads. The Dentatus screw produces more severe stress concentrations than the Unitek, Whaledent, Radix, and Kurer dowel designs; this is true both during installation and under load.
Masticatory muscle activity before and after elimination of balancing side occlusal interference
Authors: INGERVALL BENGT , CARLSSON GUNNAR E. 
Published: June 2007

SummaryThe activity of the masseter and anterior and posterior temporal muscles was studied by electromyography (EMG) in thirteen subjects with unilateral balancing side interferences and in twelve control subjects without such interferences. In both groups the EMG recordings were made during postural activity and various functions of the masticatory system and in the interference group they were repeated on two occasions following occlusal adjustment.The postural muscle activity was significantly lower in the interference than in the control group while there was no difference during maximal bite. The number of chewing cycles was greater and the act of chewing was somewhat longer in the interference than in the control group. During swallowing of water the maximal mean voltage amplitude was smaller in the interference than in the control group.The findings are discussed in relation to previous results and the conflicting ideas concerning occlusal factors in the aetiology of mandibular dysfunction.
Comparison of intra‐oral long‐cone paralleling radiographic surveys and orthopantomographs with special reference to the bone height
Authors: ADRIAENS P. A. , DE BOEVERW J. , VAN DE VELDE F. 
Published: June 2007

SummaryA comparison between bone height scores from long‐cone paralleling radiographic surveys and orthopantomographs (Panex‐EC) of forty‐one patients was made. Intra‐examiner reliability and inter‐examiner objectivity of the measuring method (Schei ruler) proved to be very good (r = 0.954 and r = 0.923 respectively for the intra‐oral surveys; r = 0.928 and r = 0.916 respectively for the orthopantomographs). Distribution and frequency of the non‐measurable surfaces were evaluated. In each technique an attempt was made to discern the main cause of non‐measurability: overlapping of adjacent structures, absence of the surface and absence of the apical region on the image.For twenty of the thirty‐six surfaces significant differences were found between bone height scores for corresponding surfaces in the long‐cone survey and in the orthopantomograph. In periodontal, prosthetic and conservative dentistry the long‐cone paralleling technique should be considered as the best radiographic technique.
A clinical study of the number of occlusal tooth contacts in the intercuspal position at light and hard pressure in adults
Authors: RIISE CLAES 
Published: June 2007

SummaryYoung adults and Adults were investigated with respect to the number of occlusal tooth contacts. In the habitual intercuspal position (centric occlusion) there was, on a highly significant level, a smaller number of tooth contacts at light pressure than at hard pressure.When Young adults were compared with Adults there was a significantly smaller number of contacts at light pressure in the Adults. During hard pressure, there was no significant difference between the groups. There was no significant difference in the number of tooth contacts at light and hard pressure between patients referred for orthodontic treatment and others.In the group of Young adults, approximately 5% of the contacts appeared on a restoration at light pressure, while approximately 10% did so at hard pressure. There was no significant difference between those with and without contacts on a restoration with respect to the number of contacts at light and hard pressure. If the number of contacts on study casts of 106 adults (Adults‐A), after occlusal adjustment in an articulator, was compared with the number of hard pressure contacts found clinically in thirty‐five of them, no significant difference was found.
Incisal angle adhesive resins: a 5‐year clinical survey of two materials
Authors: SMALES ROGER J. 
Published: June 2007

SummaryTwo hundred and seventy‐eight restoration examinations were made of Concise and Nuva‐fil resins used to restore fractured incisors, over periods of up to 5 years. Following the placement of wide bevels along the fracture margins, retention was achieved by using acid‐etching with bonding resins and by pins in some instances. Although the short‐term results were usually reasonable, provided that the materials had been placed and finished correctly, longer‐term findings revealed problems of resin darkening and corrosion staining of dentine from exposed pins. The Nuva‐Fil restorations were generally superior to the Concise restorations.
The influence of eye closure on muscle activity in the anterior temporal region
Authors: WIDMALM SVEN‐ERIK , ERICSSON SVEN GOTTMAR 
Published: June 2007

SummaryIn the experiments reported here the influence of eye closure upon the muscle tone in the region of the anterior temporal muscles was studied during mandibular rest in four patients with TMJ dysfunction and in four healthy subjects. The muscle activity as well as the cortical activity (EEG) of the patients was influenced by changes in visual stimulation. EMG (the anterior temporal region) and EEG (parieto‐occipital region) were recorded with needle electrodes. Ongoing EMG activity was present in all patients when their eyes were open. Closure of both eyes reduced the muscle activity by 50–100%. Closure of one eye could also abolish all activity but the degree of this influence was variable. Opening of the eyes blocked the alpha rhythm in the EEG. Simultaneously, increased activity was observed in the region of the temporal muscle. The activity level in the temporal region of the healthy subjects was very low and could easily be reduced to noise level using ordinary relaxation manoeuvres without eye closure.The results reported here indicate that visual stimulation may increase muscle tone in the temporal region probably as part of an arousal reaction. It is, however, possible that the activity might stem not from the temporalis muscle but from the temporoparietalis.
The effects of cyclic stress on dental polymethylmethacrylate
Authors: HARGREAVES A. S. 
Published: June 2007

SummaryAlternative resins to traditional denture base acrylic need to be assessed for both short‐and long‐term performance before their potential can be evaluated. Much dental materials testing is carried out on fresh material and a baseline of knowledge about the properties of aged material is incomplete. Studies have been carried out to examine the effects of thermal and environmental fluctuation on dental acrylic, with testing procedures reconsidered so as to resemble service conditions as closely as possible. Thermal cycling proved detrimental to the resin only when superimposed on intermittent partial drying out and resaturation.
Movement of abutment teeth in spring cantilever bridges: a laboratory study
Authors: GRAY H. S. , MYERS G. E. 
Published: June 2007

SummaryThe extent and directions of movements of spring bridge abutments were studied on acrylic casts with resilient steep and shallow palates and containing human molar and premolar abutments with compressible ‘periodontal ligaments’. Bridges with rigid bars and ‘flexible’ standard, long and short lengths were cast in Type IV gold, and soldered to Type III gold retainers which were pinned to the abutments. The pontic on each bar was depressed a standard 0.2 mm, and the movement of the abutments registered on a dial gauge resting against the mesio‐buccal corner of each retainer. The combination of bar length and palatal contour causing least movement of an abutment was the shortest bar to the molar abutment in the shallow palate model; indeed all bars on this model deflected the molar abutment less than similar bars on the steep palate model. Differences in palatal contours did not affect the extent of movements of the premolar abutments which were comparable to molar movements in the steep palate model. Abutment teeth moved mesio‐buccally when the pontic was depressed, and the elbow of the bar usually moved off the palate indicating the fulcrum was positioned along the anterior section of the bar.
The effects of cyclic stress on dental polymethylmethacrylate
Authors: HARGREAVES A. S. 
Published: June 2007

SummaryMechanisms of fatigue failure in polymers and the aims of fatigue testing have been examined, and factors affecting testing summarized. In the light of available work in several fields, parameters have been suggested for realistic flexural fatigue testing of denture base resins. A testing machine has been developed, with which the changes in properties of acrylic resin after fatigue in different environments can be studied. These changes developed gradually after 104 cycles and were related to the development of bulk crazing rather than to thermal effects. The amount of decay in the elastic modulus was not such that the material could have been said to have ‘failed’.
Assessment and treatment of stress in myofascial pain‐dysfunction syndrome: a model for analysis
Authors: HABER JOEL D. , MOSS ROBERT A. , KUCZMIERCZYK ANDREW R. , GARRETT JAMES C. 
Published: June 2007

SummaryMyofascial pain dysfunction (MPD) syndrome has received widespread attention in the dental and psychological literature. The present paper considers issues concerning a stress‐related muscular hyperactivity theory of MPD syndrome. A review of the empirical evidence as well as methodological problems evident in these studies has been noted. In addition, definition aspects of stress and a conceptual model of stress in clinical use is presented. A functional analysis of the problem components will help determine a proper treatment protocol for patients suffering from stress‐related myofascial pain. A discussion of the conceptual model for assessment and treatment purposes is presented and its implications for future research noted.
An assessment of new dental ultraviolet sources and u.v.‐polymerized fissure sealants
Authors: MAIN C. , CUMMINGS A. , MOSELEY H. , STEPHEN K. W. , GILLESPIE F.C. 
Published: June 2007

SummaryThe performance of six dental ultraviolet (u.v.) sources was assessed to establish minimum output requirements and possible u.v. hazards. Exposure criteria for u.v.‐cured materials (Nuva‐seal P.A., Nuva‐cote P.A., Nuva‐fil P.A., Lee‐seal, u.v.‐Dentoseal, Uviobond, Visiobond) were assessed by determining setting time‐intensity characteristics, u.v. transmission and microhardness as a function of u.v. intensity and depth. A minimum intensity of 10 mW cm−2 was required for adequate curing and both Nuva‐seal P.A. and Nuva‐cote P.A. set well in depth with realistic exposures. Total u.v. outputs, average intensities and spatial distributions were assessed for the u.v. sources, most of which were well above minimum requirements. Ultraviolet spectra and maximum permissible exposure measurements indicated that all of the sources were safe in normal use.
Optical properties of composites of selected shades in white light
Authors: POWERS J. M. , YEH C. L. , MIYAGAWA Y. 
Published: June 2007

SummaryLight reflectivity, scattering coefficient, absorption coefficient, infinite optical thickness, and contrast ratio were determined in white light, for seven shades of a conventional composite and five shades of a microfilled composite, from reflection spectrophotometric data using Kubelka's equations. Significant differences among shades were observed for each property. Values of infinite optical thickness ranged from 2–97 to 5–90 mm among the shades studied.
Diagnosis of the aesthetic components of the mandibular anterior prosthesis
Authors: LORTON LEWIS , WHITBECK PETER 
Published: June 2007

SummaryThis paper explores seven different factors which should be considered when prescribing the lower anterior prosthesis: alignment as seen from the incisal; height of the incisal edges; degree of irregularity of the teeth; character of the incisal edge; height of the cuspid; mesio‐incisal angle of the cuspid; and ridge coverage. The weights and variations of these different factors are discussed and suggestions made for a complete work authorization.
Antibacterial and mechanical properties of restorative materials combined with chlorhexidines
Authors: JEDRYCHOWSKI JOSEPH R. , CAPUTO ANGELO A. , KERPER STEVEN 
Published: June 2007

SummaryChorhexidine gluconate or chlorhexidine dihydrochloride were added to a composite resin and a glass ionomer restorative material in concentrations of 0,1,2,3,5, and 10% by weight. Antibacterial activity was measured by inhibition of growth of S. viridans, S. pyogenes, S. mutans, L. acidophilus, and E. coli. for 4 days.Compressive, tensile, and restorative material‐enamel adhesive shear strength tests were performed. The addition of chlorhexidine gluconate or chlorhexidine dihydrochloride increased the antibacterial activity of the composite resin and the glass ionomer restorative material and changed the mechanical properties of the restorative materials. The addition of chlorhexidine dihydrochloride resulted in mechanical properties closest to controls.
Laser techniques for the evaluation of wear in Class II restorations
Authors: WILLIAMS D. F. , CUNNINGHAM J. , LALOR M. J. , GROVES D. , ATKINSON J. T. 
Published: June 2007

SummaryA technique for the quantitative determination of the changes in surface topography of restorations during wear has been developed. This involves the optical contouring of the surface using a laser, and the generation of contour maps. Several different methods for interpreting these maps are discussed. A computer‐aided method is the most consistently accurate and measures wear volume to an accuracy of 2–5%.
Solubility of enamel powder following treatment with a sodium‐n‐lauroyl sarcosinate containing toothpaste in the presence and absence of fluoride
Authors: RAJSTEIN J. , FUKS M. , MARKITZIU A. , GEDALIA I. 
Published: June 2007

SummaryToothpaste solution exerts an inhibitory effect on dissolution of enamel in acidic solution. The presence of a detergent will not predispose enamel to acid dissolution or affect the inhibitory effect of fluoride on dissolution.