bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluoride release from aesthetic dental materials
Authors: Preston A. J. , Mair L. H. , Agalamanyi E. A. , Higham S. M.
Published: March 2003

The objective of the study was to compare the amounts of fluoride released by two glass–ionomer cements, a resin‐modified glass–ionomer cement, a compomer and a fluoride‐containing composite into deionized water and artificial saliva. Disc samples of each of the materials were fabricated and placed in either water or artificial saliva. Fluoride analysis of the media was performed periodically over 64 days. The data were analysed to show the rate of fluoride release per cm2 per hour for each material. The results showed that the fluoride release rate for all the materials in both solutions decreased dramatically after 24 h. The release rate in artificial saliva was significantly less than in water (P<0·001). The resin‐modified glass–ionomer cement consistently displayed the highest fluoride release rate per hour into both media.
Influence of mandibular length on mouth opening
Authors: Dijkstra P. U. , Hof A. L. , Stegenga B. , De Bont L. G. M.
Published: March 2003

Theoretically, mouth opening not only reflects the mobility of the temporomandibular joints (TMJs) but also the mandibular length. Clinically, the exact relationship between mouth opening, mandibular length, and mobility of TMJs is unclear. To study this relationship 91 healthy subjects, 59 women and 32 men (mean age 27·2 years, s.d. 7·5 years, range 13–56 years) were recruited from the patients of the Department of Oral and Maxillofacial Surgery of University Hospital, Groningen. Mouth opening, mobility of TMJs and mandibular length were measured. The mobility of TMJs was measured as the angular displacement of the mandible relative to the cranium, the angle of mouth opening (AMO). Mouth opening (MO) correlated significantly with mandibular length (ML) (r=0·36) and AMO (r=0·66). The regression equation MO=C1×ML×AMO+C2, in which C1=0·53 and C2=25·2 mm, correlated well (r=0·79) with mouth opening. It is concluded that mouth opening reflects both mobility of the TMJs and mandibular length.
The expression of substance P in human temporomandibular joint samples: an immunohistochemical study
Authors: Yoshida H. , Fujita S. , Nishida M. , Iizuka T.
Published: March 2003

The expression of neuropeptide substance P was examined in 18 human temporomandibular joint (TMJ) samples with internal derangement of the TMJ, and in 10 control specimens. The examination was carried out using an immunohistological technique, using paraffin‐embedded tissue and specific anti‐human substance P polyclonal antibody. We noted five characteristic distribution patterns of substance P expression: at the nerves’ fibre bundles in the connective tissues of the anterior and/or posterior attachment; around the blood vessels in the attachments; at the margin of the TMJ disc and synovial membrane layer; on the surface of hypertrophic synovial membranes with inflammation and proliferation; and around the newly formed capillaries in the TMJ discs. In TMJs with internal derangement associated with severe pain, we found distinct substance P expression in most of the specimens. The expression was particularly intense at the margin of the TMJ disc and synovial membrane layer, on the surface of hypertrophic synovial membranes and around the newly formed capillaries in the TMJ discs. The clinical symptoms of internal derangement of the TMJ are thought to be associated with the degree of synovitis. We conclude that the expression of substance P seems to be closely related to histopathological changes of the human TMJ with internal derangement.
Fracture resistance of four different restorations for cuspal replacement
Authors: Segura A. , Riggins R.
Published: March 2003

The purpose of this study was to compare the fracture resistance of four posterior restorations involving an entire cusp replacement. Four groups were established, each containing eight caries‐free mandibular molars, similar in size and anatomic form. A mesio‐occlusal preparation including the lingual cusp was prepared on all teeth. Group A were restored with a pin‐retained amalgam. Group B were restored with amalgam and a meta adhesive. Group C were restored with a composite resin with a beta‐glass quartz insert. Group D were restored with composite resin and a HEMA adhesive. All specimens were mounted in acrylic and stored in artificial saliva for 30 days. Each specimen was loaded in compression at a 90° angle in an Instron testing machine with a crosshead speed of 0·5 cm/min. Results demonstrated the mean (SD) failure loads in kilograms for each group to be: A, 1155 (388); B, 1232 (436); C, 1345 (375); D, 1595 (373). Analysis of variance indicated no significant difference among groups at P<0·05. Although the values for the composite resin restoration with the adhesive were higher than the other restorative techniques.
Effect of etching and sandblasting on bond strength to sintered porcelain of unfilled resin
Authors: Kato H. , Matsumura H. , Atsuta M.
Published: March 2003

This study determined the bond strength of an unfilled resin joined to a feldspathic porcelain for the purpose of evaluating the retentive performance of the prepared material surfaces. Porcelain disks (VMK 68 dentin) were either air abraded with alumina (AAA) or etched with one of the following five etchants: (1) ammonium hydrogen bifluoride (AHB); (2) acidulated phosphate fluoride (APF); (3) hydrofluoric acid (HFA); (4) phosphoric acid (PHA); and (5) sulfuric acid‐hydrofluoric acid (SHF). Specimens ground with abrasive paper were also used as controls. After surface preparation, the two different sized porcelain disks were bonded together with a methyl methacrylate‐based resin initiated with tri‐n‐butylborane (MMA‐TBB resin). Shear bond strengths were determined both before and after thermocycling. Before the thermocycling, the greatest bond strengths (21·3 and 23·7 MPa) were generated with the use of the SHF and HFA agents, followed by the AHB agent (18·4 MPa). Reduction in bond strength after thermocycling was significant for all groups, although the SHF‐ and HFA‐treated groups exhibited bond strengths greater than 15 MPa even after the thermocycling. The results indicated the effectiveness of the SHF‐ or HFA‐etching for retaining the acrylic resin to the porcelain. However, ageing testing also revealed insufficient retentive characteristics of the acrylic resin by etching alone.
Titanium for removable denture bases
Authors: Da Silva L. , Martinez A. , Rilo B. , Santana U.
Published: March 2003

The aim of the present study was to compare titanium‐base and resin‐base maxillary complete dentures. In 13 patients with a maxillary complete denture with a titanium base (group I) and in 12 patients with a maxillary complete denture with a resin base (group II), the (a) patient's adaptation to the denture, (b) denture retention and (c) appearance of the mucosa under the denture were evaluated. In all cases, the adaptation was assessed with a questionnaire, while the retention and the appearance of the mucosa were assessed by clinical examination. None of the three measures considered (adaptation, retention and mucosa appearance) differed significantly between patients with titanium‐base dentures and patients with resin‐base dentures. Titanium bases are suitable for dentures likely to be subject to severe mechanical stresses (as in the case of maxillary complete dentures opposing natural teeth), and in patients who show hypersensitivity responses to other materials.
Effects of timing and heat treatment of silanated porcelain on the bond strength
Authors: Barghi N. , Berry T. , Chung K.
Published: March 2003

This study examined the effects of post‐silanization interval and heat treatment on shear bond strength of composite resin to porcelain. One hundred and eighty square‐shaped specimens were fabricated and sanded flat sequentially. The specimens were then randomly placed into six groups and 18 subgroups of 10 specimens each. An experimental and three commercially available silane systems, including two one‐mix and one two‐mix systems, were tested in this study. No silane treatment specimen was used as control. Specimens from the experimental and one of the Mirage groups were selected for heat treatment for 60 min at 60 °C. Three post‐silanization intervals were scheduled. After incubation, a dual cure composite resin (Mirage FLC) was placed on the silanated surfaces and light‐cured. All specimens were stored in 37 °C, 2% saline solution for 1 week and subjected to shear test using an Instron machine with cross‐head speed of 5 mm/min. ANOVA and Scheffe tests were used to analyse data with confidence level at 95%. The mean values of the shear bond strengths ranged from 2·8 to 23·3 MPa. All groups showed significantly higher bond strength than the control group at the 3 min, 24 h and 1 week post‐silanization periods (P<0·05). Heat treatment groups recorded an increase in the shear bond strength and maintained significantly higher bond strength values (P<0·05). In conclusion, bond strength of composite resin to porcelain resulting from silanization of porcelain increased after heat treatment and during the post‐silanization periods. The bond strength also varied for different silane coupling agents tested in this study especially in the one‐mix system.
Tooth loss and the condition of the prosthodontic appliances in a group of elderly home residents
Authors: Ćatović A. , Jerolimov V. , Ćatić A.
Published: March 2003

The study assessed the number of missing teeth, the state of the existing prosthodontic appliances and the need for their replacement. Dental status and anamnesis were taken on a group of 120 elderly home residents by trained examiners. Prosthodontic appliances were evaluated according to the Karlsson's index for the crowns and bridges, and according to the modified Nevalainen et al. index for the evaluation of the complete dentures, as well as the need for prosthetic treatment. The most persistent teeth in both jaws were lower canines, while the most commonly missing teeth were lower first molars. On average, the crowns were older and in poorer condition than the bridges. Lower complete dentures had better stability but were also less retentive in comparison with the upper complete dentures. More than 82% of the subjects were in need of either fixed, removable or combined prosthodontic treatment. The high prevalence of needs for prosthodontic treatment pointed to the requirement for frequent dental check ups within elderly home residents in order to better identify and meet their dental needs.
Regulation of human jaw tapping force with visual biofeedback
Authors: Suenaga H. , Yamashita R. , Yamabe Y. , Torisu T. , Yoshimatsu T. , Fujii H.
Published: March 2003

The purpose of this study, which made use of visual biofeedback, was to determine whether jaw tapping force reproduction is related to the strength of tapping and to investigate how jaw tapping force affects the tapping movement curve. Nine healthy examinees were asked to reproduce jaw tapping force. We found that the ease and method of regulating jaw tapping force differed depending on the target force. We also found that jaw tapping force was regulated by alteration of the jaw opening distance, the duration of the tooth contact phase, the duration of the jaw closing phase, the maximum jaw opening velocity, and the maximum jaw closing velocity. However, the duration of the jaw opening phase and cycle time was not affected by force regulation under our experimental conditions.
Spectral characteristics of hypernasality in maxillectomy patients 1
Authors: Yoshida H. , Furuya Y. , Shimodaira K. , Kanazawa T. , Kataoka R. , Takahashi K.
Published: March 2003

To reveal the acoustic characteristics associated with hypernasality and to ascertain their correlation to the severity of hypernasality, 30 speech samples produced by 15 maxillectomy patients were acoustically analysed with and without an obturator prosthesis in place. The isolated, sustained Japanese vowel /i/ was used as the stimulus for acoustic measurement and perceptual judgment to evaluate the severity of hypernasality. Normalized 1/3‐octave spectral analysis demonstrated the spectral characteristics of hypernasality as a rise in amplitude between the first and second formants around the 1 kHz region, and a reduction in amplitude of the frequencies higher than the second formant. High correlation was shown between the perceptual ratings and the predicted values derived from stepwise regression analysis.
Long‐term survival estimates of cast gold inlays and onlays with their analysis of failures
Authors: Studer S. P. , Wettstein F. , Lehner C. , Zullo T. G. , Schärer P.
Published: March 2003

The aim of the present study was to assess the clinical behaviour of cast gold restorations with respect to define a gold control against current and future ceramic and composite restorations. The study sample included 50 patients with 303 cast gold restorations. All restorations were cemented with a non‐adhesive technique. A total of 303 restorations were evaluated clinically and radiographically using modified United States Public Health Service criteria. Restorations recorded as having an A‐ or a B‐rating were defined as successful. Of the 303 restorations, 42 were judged as failures, which resulted in a failure rate of 13·8% for a mean observation time (±s.d.) of 18·7 (±9·5) years. The estimated Kaplan–Meier survival rates (±s.e.) were 96·1% (±1·1%) at 10 years, 87·0% (±2·2%) at 20 years and 73·5% (±5·4%) at 30 years. In total, biological reasons were counted 25 times in comparison to 17 technical reasons for those 42 failed cast gold restorations, with 17 secondary caries (40%) as the most common biological reason and with 13 retention losses (31%) as the most common technical reason. The endodontically treated tooth was exclusively identified as a risk factor. The restoration type (inlay versus onlay) did not influence the survival rate.
Flexural strength of rebased denture polymers
Authors: Archadian N. , Kawano F. , Ohguri T. , Ichikawa T. , Matsumoto N.
Published: March 2003

The properties of denture base and reline resins may be affected by daily changes between room temperature and mouth temperature. The purpose of the study was to evaluate the effect of thermocycling on the flexural strength of the relined denture base polymer with reline resin. Three denture base resins, three hard reline resins and their combinations were tested. Fourteen specimens, 65×10×2·5 mm, were fabricated for each material. Polymer combination specimens were made using 1·5 mm hard reline resin on 1·0 mm cured denture base resins. Half of the specimens were stored for 50±2 h in distilled water at 37 °C, while the other half were thermocycled for 20 000 cycles between 4 and 60 °C. Three point bending tests were conducted on a universal testing machine at a cross‐head speed of 0·5 cm/s. The flexural strengths were measured and a statistical analysis was performed on the data using three‐way anova (P<0·05). The results showed that the flexural strength of relined denture base polymer was significantly higher than that of hard reline polymer. Thermocycling did not affect the flexural strength of the relined denture base polymers, whereas the denture base polymer and reline polymer alone showed a decrease in strength after thermocycling.
Patients’ satisfaction in two long‐term clinical studies on resin‐bonded bridges
Authors: Creugers N. H. J. , De Kanter R. J. A. M.
Published: March 2003

This study aimed to evaluate patients’ satisfaction with resin‐bonded bridges and the effect of failures on the degree of satisfaction. In two clinical trials, 358 patients completed guided questionnaires at regular recalls (n=1484). In this way, data regarding ‘overall function’, ‘colour’, ‘shape’, ‘functional changes’, ‘complaints’ and ‘recommendation to other patients’ were obtained. The scores of each criterion were evaluated for the variables ‘trial’, ‘gender’, ‘time after placement’ and ‘failure’, using 4‐way
anova. Encountered failures were rated using a ‘failure severity scale’. For all combinations of measurement periods, the changes in patient's opinions were calculated and the differences tested using the paired t‐test. Overall satisfaction was correlated with ‘colour’, ‘shape’ and inversely correlated with ‘complaints’ (r>0·34; all P<0·005). No statistical differences were found between males and females. No significant changes were observed in patient satisfaction over time. Failures influenced the failure sensitive variables ‘functional changes’ and ‘avoidance of load’. The z‐scores were independent of the severity of the failures (r<0·13; all P>0·10). The degree of patient satisfaction with resin‐bonded bridges appeared to be high and did not seem to be influenced by the occurrence of failure.
Presence of microorganisms on the fitting denture complete surface: study ‘in vivo’
Authors: Monsenego P.
Published: March 2003

It was the intention to study if glazing the fitting surface of maxillary dentures with a light‐curing acrylic resin would diminish the bacterial counts. The study included the application of a photopolymerizing glaze to one half of the fitting denture surface; after 15 days microbial plaque was collected from a 1 cm2 area of the glazed and the untreated resin, respectively. At the same time bacteria were collected from a 1 cm2 area of the corresponding sites on the palatal mucosa. The application of the glaze had modified the number of bacteria cultured from the glazed surface versus the untreated surface. Denture surface: total aerobic bacteria, 1:4; aerobic streptococci, 1:4; aerobic staphylococci, 1:5; anaerobic bacteria, 1:3·5; mucosal surface aerobic bacteria, 1:4; streptococcal, 1:4. The differences were statistically significant at P<0·002. However, from a quantitative and qualitative point of view these differences were minor compared with the actual concentrations of the microorganisms of 104–106/cm2 observed on the fitting denture surface and the palatal mucosa.
Development of a new device for recording condylar head movement
Authors: Shibasaki K. , Fujita Y. , Yamasawa H. , Fukuyama E. , Soma K.
Published: March 2003

Several excellent devices have recently been developed to precisely record mandibular movement. However, these devices are not always suitable for use under certain conditions, such as during sleep, because they incorporate a face bow unit. We report here a newly developed, easy and convenient recording device that does not require the use of an instrument within the mouth. Instead, a subminiature pressure transducer is inserted between the outer surface of a fixation device in the external auditory meatus and the anterior cutaneous surface of the external auditory meatus. The fixation device was made using silicone impression material in the shape of the inner external auditory meatus. Following moulding, the material was cut in half and the parts were reconnected using a coiled spring. This method is based on a routine clinical method for palpating the external auditory meatus to observe condylar head movement. By comparing the results obtained using this device with those obtained using CADIAX, we confirmed that it is useful for recording the movement of the condylar head in routine clinical examinations.
Acoustic emissions generated in aged dental composites using a laser thermoacoustic technique
Authors: Lee S.‐Y. , Lin C.‐T. , Dong D.‐R. , Huang H.‐M. , Shih Y.‐H.
Published: March 2003

The heating up of dental composites by laser will produce acoustic emissions (AEs) that may be related to fracture mechanisms in the composites. It has been proved that the mechanical properties of dental composites are affected by storage in food simulating liquids, i.e. 75% ethanol, which has a solubility parameter approximating to that of bisphenol glycidyl dimethacrylate (BisGMA) resin. A new method was innovated to evaluate the laser‐induced AEs in dental composites aged by 75% ethanol solution. Model systems (50/50 BisGMA/TEGDMA resin filled with 0% and 75 wt.% 5–10 μm silanized BaSiO6) as well as three commercial composites (Marathon One, Z100 and Herculite XRV) were used in this study. Nine samples acting as the control group were tested to establish the correlation of AEs to laser power. The effect of ageing by immersion in 75% ethanol on AEs and diametral tensile strength (DTS) was then evaluated. A quasi‐continuous wave CO2 laser was used to heat up the composites. AEs of frequency 100–200 kHz were collected, filtered, recorded and processed using a 4610 Smart Acoustic Monitor. Burst patterns, which formally were assumed to be correlated to fracture mechanisms, were also identified from the data obtained at laser power ≥5 W for commercial composites and ≥4 W for model systems. Higher laser powers cause the AE to increase for all composites except unfilled model resin. AEs as a function of power for all aged systems were flat (<100 events) below 4 W. Emissions then rose sharply to> 1000 events at 7·1 W. Statistically significant differences were found between the AEs obtained at 5 W (commercial composites) and those at 4·3 W (model systems) for material systems and storage times. Marathon One was less affected by the laser and an abrupt change in AE was found between days 0 and 7 of storage for all commercial composites. The AE value from the unfilled model resin was found to be significantly different from that of the model composites. However, they showed an increase in AEs with length of storage time, which was inversely associated with the decreased tendency of their immersed DTS values. Laser‐induced AEs may be a valuable adjunct to conventional mechanical testing.
A century of controversy regarding the benefit or detriment of occlusal contacts on the mediotrusive side
Authors: Marklund S. , Wänman A.
Published: March 2003

Many opinions have been presented in the literature during the past century regarding so‐called mediotrusive/balancing/non‐working side contacts. During the first half of this century, most authors advocated the advantage of these contacts (it was more or less the state of the art in prosthetic treatments), while during the last 50 years mediotrusive side contacts/interferences have mostly been regarded as a disturbing factor in the functioning of the mandible. Recently, it has been proposed that mediotrusive side contacts have a protective effect on the temporomandibular joint (TMJ). The aim of this study was to review opinions advocated during the twentieth century regarding the advantages and disadvantages of having contacts on the mediotrusive side during lateral excursions of the mandible. We conclude that, at present, there is no uniform body of scientific evidence supporting a balanced occlusion in favour of a mutually protective occlusion or vice versa. Longitudinal studies based on cohorts with different types of occlusal contacts, estimating the risk among these of developing signs and symptoms of temporomandibular disorders, are generally lacking and could provide valuable knowledge in this field.
Human masticatory muscle activity and jaw position under experimental stress
Authors: Tsai C.‐M. , Chou S.‐L. , Gale E. N. , Mccall W. D.
Published: March 2003

The purpose of the present study was to determine whether stress induced a consistent pattern of increased electromyographic (EMG) activity in different masticatory muscles, and whether stress produced changes in jaw position. Thirty‐five dental students at Taipei Medical College volunteered for this study. Mental arithmetic was used to create a stress condition and relaxation instruction was used to help relax the subjects. Subjects were asked to evaluate the stress they felt under each experimental condition with a visual analogue scale (VAS). Surface electrodes were used to monitor the EMG activities of the right masseter, right posterior temporalis and suprahyoid muscles. A kinesiograph was used to observe the jaw position. Data collected before mental arithmetic or relaxation monitored the baseline level. The VAS means were significantly increased during the stress condition and significantly decreased following relaxation, compared with the baseline. There was also a significant increase in EMG activity of all three muscles during mental arithmetic compared with baseline; different patterns of increased EMG activity were noticed in the three muscles under a continuous stress condition. Under stress, the incidence of tooth contact at intercuspal position was also increased.
Association of horizontal and vertical overlap with prevalence of temporomandibular disorders
Authors: Ćelić R. , Jerolimov V.
Published: March 2003

The aim of the study was to evaluate the relationship between horizontal (HO) and vertical overlap (VO) and prevalence of temporomandibular disorders (TMD) in a non‐patient population. Out of the total number of subjects (230), 65·7% subjects were classified as asymptomatic, 5·7% subjects had muscle disorders (MD) (myalgia), 9·1% subjects had disc displacement with reduction (DDR), while 19·6% subjects had disc displacement with reduction associated with muscle disorder (DDR + MD) (myalgia). The HO equal to or greater than 5 mm was significantly more prevalent in the symptomatic patients (MD, DDR, DDR + MD) than in the asymptomatic group (P < 0·001). The VO equal to or > 5 mm also demonstrated statistically significant difference (P < 0·006) between the symptomatic (suffering from DDR, and DDR + MD) and asymptomatic subjects. Conclusion of the study is that the HO and VO equal to or > 5 mm was more present in the group of subjects with diagnosis of a TMD (DDR and MD), what distinguishes this group from the group of asymptomatic subjects.
Effect of cooling procedure on final denture base adaptation
Authors: Ganzarolli S. M. , Rached R. N. , Garcia R. C. M. R. , Del Bel Cury A. A.
Published: March 2003

Summary Well‐fitted dentures prevent hyperplasic lesions, provide chewing efficiency and promote patient's comfort. Several factors may affect final adaptation of dentures, as the type of the acrylic resin, the flask cooling procedure and the water uptake. This investigation evaluated the effect of water storage and two different cooling procedures [bench cooling (BC) for 2 h; running water (RW) at 20 °C for 45 min] on the final adaptation of denture bases. A heat‐cured acrylic resin (CL, Clássico, Clássico Artigos Odontológicos) and two microwave‐cured acrylic resins [Acron MC, (AC) GC Dent. Ind. Corp.; Onda Cryl (OC), Clássico Artigos Odontológicos] were used to make the bases. Adaptation was assessed by measuring the weight of an intervening layer of silicone impression material between the base and the master die. Data was submitted to ANOVA and Tukey's test (0·05). The following means were found: (BC) CL=0·72 ± 0·03 a; AC=0·70 ± 0·03 b; OC=0·76 ± 0·04 c//(RW) CL= 1·00 ± 0·11 a; AC=1·00 ± 0·12 a; OC=0·95 ± 0·10 a. Different labels join groups that are not statistically different (P > 0·05). Comparisons are made among groups submitted to the same cooling procedure (BC or RW). The conclusions are: interaction of type of material and cooling procedure had a statistically significant effect on the final adaptation of the denture bases (P < 0·05); water storage was not detected as a source of variance (P > 0·05) on the final adaptation.
Evaluation of the accuracy and reproducibility of a replication technique for the manufacture of electroconductive replicas for use in quantitative clinical dental wear studies
Authors: Chadwick R. G. , Mitchell H. L. , Ward S.
Published: March 2003

This work sought to evaluate the accuracy and reproducibility of a replication process that formed electroconductive replicas from addition cured silicone impressions for the purposes of monitoring tooth surface loss. Replicas were constructed by painting the surface of impressions with one of three high silver content electroconductive paints [Electrocure (EC), RS Silver Paint (SP) and Electrolube (EB)] and, once dry, backing this up with a cyanoacrylate based gel material (Zapit) and die stone. For each paint an impression was recorded of a gauge block of known step height (1270 μm) and five impressions of the palatal surface of a laboratory standard maxillary central incisor were also recorded. All impressions were taken using an addition cured silicone impression material (President). The resultant electroconductive replicas were mapped using a computer controlled probe. This data was analysed to determine both the replica's step height and, using surface matching techniques, the reproducibility of the replication process. The mean step heights recorded were; EC=1268·43 (s.d.=12·09), SP=1267·09 (s.d. 1·77) and EB 1299·58 (s.d. 14·47). Both EC and SP recorded the step height to within 3 μm. In the repeat replication of the palatal surface of an upper central incisor SP maintained a greater constancy of surface topography (99·6%) that was statistically superior to both EC (P < 0·05) and EB (P < 0·01). The SP was therefore the preferred paint for this technique. Bearing this in mind the replication technique was both accurate and reproducible but vigilance, as to the selection of paint for the process, should be exercised so as not to affect the good accuracy and reproducibility of the technique.
The effects of mouthrinses on microhardness and colour stability of aesthetic restorative materials
Authors: GÜRDAL P. , AKDENIZ B. GÜNIZ , HAKAN SEN B.
Published: March 2003

Summary Detrimental effects exerted on oral and dental tissues by frequent mouthrinse use are observed, but studies about their effects on aesthetic restorative materials are limited. In this study, the purpose was to examine the effects of three proprietary mouthrinses on three different aesthetic restorative materials. Mouthrinses were used as treatment groups, while distilled water served as the control. From a total of 72 specimens, each experimental group consisting of 24 samples were prepared from each restorative test material by using metal moulds. The samples were stored in 20 mL of one of the mouthrinses for 12 h, which was reported as the equivalent time to 1 year of 2‐min daily mouthrinse use. Changes between baseline and after treatment measurements of surface microhardness and colour of the test materials were established by using Vickers microhardness tester and spectrophotometer. Statistical analyses were performed by analysis of variance (anova), with Bonferroni correction. The level of significance was set as 0·05 in all tests. There were no significant interactions between the test solutions and the test materials with regard to microhardness (P > 0·05), and colour changes of the materials (P > 0·05). Effects of mouthrinses on restorative materials may differ depending on many in vivo factors that could not be replicated in vitro. Therefore, routine assessment of the effects of mouthrinses on aesthetic restorative materials is recommended.
Degree of polymerization of resin composites by different light sources
Authors: Yoon T.‐H. , Lee Y.‐K. , Lim B.‐S. , Kim C.‐W.
Published: March 2003

summary  The purpose of this study was to determine the effectiveness of polymerization in the newly introduced blue light emitting diode (LED) (Experimental, SNU, Korea), and plasma arc curing (PAC) (Apollo 95E, Elite, DMD, USA) compared with conventional halogen lamp (Spectrum 800, Dentsply, USA). Various irradiation time with fixed intensity of light‐curing units (LCUs) were irradiated to produce the same total light energy. The degree of double bond conversion (DC) of three resin composite (shade A3) was measured with a Fourier‐transform infrared (FT‐IR) spectrophotometer at various depths from the surface. Immediately after exposure to light, 100 μm thickness of resin composite was sectioned at the 1, 2, 3 and 4 mm from the top surface. The infrared spectrum of uncured resin and each wafer specimen were then obtained. The results were as follows: DC was significantly influenced by three variables of material, depth from the surface, and light source and energy level (P < 0·01). When the same light energy was irradiated, DC by plasma arc and LED was not significantly different from the halogen lamp (P > 0·05). When light energy was increased twice, no significant difference in DC was observed up to 2 mm from the surface (P > 0·05), but DC increased significantly from 3 mm (P < 0·05).
Maximum bite force after the replacement of complete dentures
Authors: MÜLLER F. , HEATH M. R. , OTT R.
Published: March 2003

In complete denture wearers the maximum bite force (MBF) is known to be considerably lower than in dentate people. Low MBF might therefore be an indication of poor denture fit but there is limited evidence on this. Therefore, the aim of the present study was to investigate whether MBF can be improved by the replacement of complete dentures for elderly people.

Nine edentulous volunteers, average age 74·2 ± 5·5 years and average denture experience 19·4 ± 19·5 years (1–50 years), had replacement dentures made. Functional impressions were taken after border moulding using zinc oxide eugenol paste. After a rehearsal session, MBF was recorded with the old dentures, and with the new dentures immediately at insertion, at 3, 8 days, 2–3 weeks, 1, 2, 3 and 6–10 months post‐insertion (p.i.). The MBF was recorded with the central bearing point method using a full‐bridge strain gauge with a confirmed linearity from 1 to 1000 N and an accuracy of ±1 N. Data were analysed off‐line using the mean of two peak readings per patient per session.

The results indicate that MBF tended to be impaired when replacement dentures were first fitted (n.s.). However, this trend reversed during the first month p.i. for patients with a ‘moderate’ lower ridge resorption of Atwood (1963) grade 3 or 4 (n=5). Patients with more severe lower ridge resorption (Atwood grade 5 or 6; n=4) showed a significantly lower MBF over the entire observation period (P=0·05) and took longer to regain bite strength. Only patients with moderate bone resorption exceeded their pre‐insertion level of MBF within the observation period of 6–10 months p.i. In contrast to one report of immediate improvement of MBF at insertion of a new or relined denture (Leyka et al., 2000), the present study suggests that, at least for elderly patients with severe bone resorption, delayed improvement of MBF should be expected.
A comparison of the erosive susceptibility of cuspal and cervical enamel using an ultrasonic technique
Authors: Hammadeh M. , Rees J. S.
Published: March 2003

summary  The aim of this study was to compare the erosive susceptibility of cuspal and cervical enamel from human premolar and molar teeth. Small blocks of cervical and cuspal enamel were immersed in either orange juice or Coca‐Cola at 37 °C and the surface enamel loss was measured by surfometry at 1, 2, 3 and 4 h. Additionally, once‐hourly enamel loss was measured, specimens were placed in an ultrasonic bath containing water and ultrasonicated for 5 s to determine the degree of surface demineralization. A further set of enamel specimens were prepared that had 100 μm of the enamel surface removed. This was done to remove the hypermineralized surface enamel layer. Surface enamel loss in orange juice at 4 h, following ultrasonication, ranged from 13·2 to 16·9 μm. The surface enamel loss in Coca‐Cola at 4 h, following ultrasonication, ranged from 21·7 to 27·5 μm. Subsurface enamel loss in orange juice at 4 h, following ultrasonication, ranged from 10·7 to 16·1 μm. The subsurface enamel loss in Coca‐Cola for 4 h, following ultrasonication, ranged from 36·8 to 37·2 μm. Overall, little difference was found in the erosive susceptibility of cervical and cuspal enamel to the effects of orange juice or Coca‐Cola.
Stress and burnout in community mental health nursing: a review of the literature
Authors: Edwards D. , Burnard P. , Coyle D. , Fothergill A. , Hannigan B.
Published: March 2003

There is a growing body of evidence that suggests that many community mental health nurses (CMHNs) experience considerable stress and burnout. This review aimed to bring together the research evidence in this area for CMHNs working within the UK. Seventeen papers were identified in the literature, seven of which looked at stress and burnout for all members of community mental health teams (CMHTs) and the remaining 10 papers focused on CMHNs. The evidence indicates that those health professionals working as part of community teams are experiencing increasing levels of stress and burnout as a result of increasing workloads, increasing administration and lack of resources. For CMHNs specific stressors were identified. These included increases in workload and administration, time management, inappropriate referrals, safety issues, role conflict, role ambiguity, lack of supervision, not having enough time for personal study and NHS reforms, general working conditions and lack of funding and resources. Areas for future research are described and the current study of Welsh CMHNs is announced. This review has been completed against a background of further significant changes in the health service. In the mental health field, specific new initiatives will have a significant impact on the practice of community mental health nursing. A new National Framework for Mental Health, along with a review of the Mental Health Act (1983), will undoubtedly help to shape the future practice of mental health nursing.
Dissociative identity disorder: a literature review
Authors: McAllister M. M.
Published: March 2003

This paper presents a review of the literature into dissociative identity disorder. This disorder, previously known as multiple personality disorder, is increasingly diagnozed, in part because of more focused diagnostic tools, but also because people are accessing services to assist with the longterm problems of early child abuse and neglect. Dissociative identity disorder is examined in the literature according to a variety of discourses, each of which suggest different ways of conceptualizing problems and therapeutic approaches. These discourses reviewed include: psychiatry, psychology, corporeality, feminism, social constructivism, anthropology, and postmodernism. The paper concludes with an examination of the nursing literature and suggests opportunities for nursing research into this complex mental health problem.
Electroconvulsive therapy: a review of the literature
Authors: Challiner V. , Griffiths L.
Published: March 2003

Electroconvulsive therapy (ECT) is a procedure that has been used in the treatment of mental illness for over 60 years. Despite its continued use it remains a controversial treatment, with questions concerning its efficacy being raised not only by mental health professionals, but also service users themselves. The following article reviews the current literature on the administration and effectiveness of ECT, highlighting some of the main points of contention in the debate over its use. In providing a balanced review of the literature, this article aims to serve as an information source for nurses and other mental health professionals who may be involved in the administration of ECT and care of the patients receiving treatment.
‘Partnership’: a co‐operative inquiry between community mental health nurses and their clients. 1. Research methodology, process and reflections
Authors: Hostick T. , Mcclelland F.
Published: March 2003

The aim of this study was to explore the utility of co‐operative enquiry between community mental health nurses and their clients. The research design was a form of co‐operative enquiry. Two nurses and two clients volunteered to participate as co‐researchers and co‐subjects with two facilitators in a co‐operative inquiry group. The subject of the inquiry, agreed by the group, was the relationship between the nurse and client. The method for the inquiry was developed by the participants and consisted of dialogue groups. This paper provides a description of the research design and methodology with a first‐person account of the research experience and reflections by the two facilitators. The process is considered with particular reference to the influence of the study facilitators. Their position changes from wanting to influence an ‘external’ relationship to one of being influenced within the research relationship over time through reflection and growing self‐awareness. This results in the inquiry ultimately being driven by the agenda of the group rather than the process. The outcomes of the study were both informative and transformative and the content of the inquiry relating to the nurse–client relationship will be presented in a second paper.
The experience of being an adolescent child of a parent who has a mood disorder
Authors: Meadus R. J. , Johnson B.
Published: March 2003

The purpose of this phenomenological study was to describe the experiences of adolescent children living with a parent who has a mood disorder. Three female adolescents each participated in two unstructured, tape‐recorded interviews. Interviews were analysed using the Giorgi (1985) method. Three themes emerged. First, participants experienced a serious disruption in family life due to the unavailability of the ill parent, which evoked feelings of an intense sense of responsibility, fear and loss. This disruption led to the adolescent taking on parental roles and tasks. Second, participants perceived themselves to lack knowledge and understanding, leading to frustration and fears that their parents may not get better, and that they themselves may become ill like their parents. They sought information in order to better adjust to and understand the illness. Third, participants struggled to come to terms with the burden of having a psychiatrically ill parent. The effort of trying to cope and make sense of the experience involved a variety of cognitive and affective responses. Implications for nursing practice and research are discussed.
What are the criteria that mentors use to make judgements on the clinical performance of student mental health nurses? An exploratory study of the formal written communication at the end of clinical nursing practice modules
Authors: Brown N.
Published: March 2003

Issues concerning the assessment of student nurse performance in clinical practice have preoccupied nurse educationalists for some time and continue to pose problems. The debate in the nursing literature tends to revolve around two seemingly mutually exclusive positions related to competence vs. learning outcomes. These are views that seem to be held by academics with little reference to clinical nurses who have responsibility for the assessment of student performance in clinical practice. This paper adds to the wider debate on clinical assessment by reporting on a small research study that explored the written comments that 150 mentors made in relation to the performance of student mental health nurses following periods of clinical practice. An extensive literature review is provided in order to place the debate in context, followed by a brief outline of the research study, its findings, discussion and conclusion. This analysis of findings demonstrates that student learning is of major concern to mentors, and that the assessment of student performance in clinical practice is not restricted by pre‐determined behavioural learning outcomes. Personal characteristics of students exert a great influence on judgements about clinical performance. This paper does not offer solutions to the search for the perfect clinical assessment, but it does call for an increased dialogue between educationalists and mentors to discuss the implications of this research for the development of an appropriate clinical assessment tool.
Occupational stress and job satisfaction in mental health nursing: focused interventions through evidence‐based assessment
Authors: Cottrell S.
Published: March 2003

In the UK, over 20 contemporaneous reports have shown that between one‐quarter and one‐half of National Health Service (NHS) staff report significant personal distress (Weinberg & Creed 2000). There exists a substantial body of evidence to suggest that high levels of stress are endemic throughout the NHS (Anderson et al. 1996), and that many of these stressors may be unique to health care (Payne & Firth‐Cozens 1987, Calboun & Calboun 1993). Historically, responsibility for stress management has often been placed at the feet of the employee (Sutherland & Cooper, 2000). This individual orientation has lead to the development of practices designed to treat those exhibiting symptoms of stress, and a relative paucity of interventions oriented to the prevention and the management of workplace stressors. It can also serve to deter scrutiny of injurious workplace conditions, practices and procedures. This small‐scale study examines stress and job satisfaction in community mental health nurses in a semirural area of North Wales. Based on self‐report questionnaire feedback, focused interventions are described to enhance work satisfaction and help ameliorate occupational stressors. Interventions are described at the level of the individual, the team and the organization as a whole.
The value of community mental health nurses based in primary care teams: ‘switching the light on in a cellar’
Authors: Crawford P. , Carr J. , Knight A. , Chambers K. , Nolan P.
Published: March 2003

This paper explores the impact of placing Community Mental Health Nurses (CMHNs) at two primary care practices in South Staffordshire. Data were collected by means of a questionnaire which was sent to primary care personnel at these practices, to ascertain their opinions with respect to the contribution of practice‐based CMHNs. Overall, primary care personnel were satisfied with the quality of the service received from the CMHNs, especially in terms of improved communication. They felt that the new arrangements enabled a quicker and more efficient access to the services of the CMHN. The results are discussed in terms of the value of having CMHNs within the primary care setting, and in terms of service planning and future recommendations for mental health services within primary care.
Bipolar disorders: an overview of current literature
Authors: Baker J. A.
Published: March 2003

This paper aims to review current literature around bipolar disorder from a multidisciplinary stance. As a result of a literature search, several key themes have been identified which will be discussed during this paper: first, the definition of bipolar disorders, their epidemiology and the effect of the illness on outcome, and secondly pharmacological interventions, psychosocial interventions and the use of coping strategy enhancement for this client group. The paper attempts to direct clinicians towards relevant further reading and research for the development of interventions when working with this client group.
Judgement days: developing an evaluation for an innovative nursing model
Authors: Stevenson C. , Barker P. , Fletcher E.
Published: March 2003

This paper reports on the process and outcomes of the evaluation of an innovative nursing model (the Tidal Model). In relation to process, the study has been used to refine the methodology in terms of defining important variables to take as outcome measures to be analysed both descriptively and inferentially. In relation to outcomes, the pre–post‐test design has generated significant findings in relation to improved patient care.
Multi‐disciplinary working in a forensic mental health setting: ethical codes of reference
Authors: Mason T. , Williams R. , Vivian‐Byrne S.
Published: March 2003

This paper reports on a small research project on multidisciplinary team‐working within a medium secure forensic unit in the United Kingdom. Although multidisciplinary team working is widely accepted as an effective strategy for the delivery of healthcare services in modern society it is also recognized that interdisciplinary problems can also occur. This study developed two questionnaires, one being delivered to a number of groups and teams in the secure unit, whilst the second one was geared to individuals. A thematic analysis was employed to develop category building and concept formation. The results highlighted a three‐level ethical code referencing system that was employed by both individuals and groups. Within this, three domains, or trajectories, were identified that were polarized continuums of main tensions for multidisciplinary staff working in forensic practice.