Patients' perspective on dental aesthetics in a South-eastern European community

ObjectivesTo assess the importance attributed to dental aesthetics by subjects from a Romanian community. In addition, the role played by dental color, the group-distributions based on the self-evaluation of dental color and the previous experience regarding whitening treatments are analysed.MethodsA multiple-choice questionnaire was administered to 540 patients in dental offices in Cluj-Napoca, Romania; the subjects were also asked to self-evaluate their dental shade, using a set of images as a comparison. Answers to the questionnaires were statistically analysed using Microsoft Excel and SPSS 13.00 (Pearson's chi-square test, Fisher's exact test, Kendall's tau b).ResultsFrom the participants, 17.96% were motivated by aesthetic reasons to ask for treatment; most of the patients evaluated their smile as “acceptable” (38.51%) or “having some defects” (29.44%) and were self-included in groups of medium and dark shades (33.7% and 33.89%, respectively). Whilst 22.40% of the subjects considered the dental color as being the most evident defect of their dentition, 39.07% indicated a self-perception of “an abnormal dental shade”. A strong correlation between darker self-assessed tooth color-groups and the self-perception of an abnormal tooth color was found (Chi square p ? 0.001, Kendall's tau-c = 0.44, with p ? 0.001). Previous whitening treatments were reported by 8.88% of the subjects.ConclusionsAmong patients who wanted to improve one of their oral functions, the majority requested changes in aesthetics. Dental shade is one of the aspects recognized as problematic by the participants, but nonetheless the percentage of patients who had previously benefited by whitening treatments was moderate.     

Effects of blood and saliva contamination on shear bond strength of metal orthodontic brackets and evaluating certain methods for reversing the effect of contamination

The background and purposeContaminations may reduce shear bond strength (SBS) of orthodontic brackets. For reversing such effects, certain surface treatments are suggested. This study was conducted to evaluate (1) effects of saliva and blood contamination on SBS of metal brackets, (2) the efficacy of three surface treatments, while (3) using two adhesives (37% phosphoric acid etchant (Ivoclar/Vivadent) + RMGIC (Fuji Ortho LC), and self-etchant primer (iBonD GI) + composite resin (No-Mix, Dentaurum)).MethodsThe sample was categorized into 12 experimental subgroups (2 contaminations × 3 treatments × 2 adhesives, n = 12 × 10) and 2 control subgroups (n = 2 × 10). Experimental specimens underwent different treatments according to their group. They were incubated (37 °C, 96 h) and thermocycled (3000 cycles, 5–55 °C, dwell time = 30 s). SBS was tested at 1 mm/min crosshead speed.ResultsSEP–composite produced significantly lower SBS rates (P < 0.05) according to Mann–Whitney. ANOVA indicated a significant difference between blood contamination and both control and saliva contamination. According to Wilcoxon signed rank test, comparing with SBS = 7, drying failed to achieve appropriate SBS rates (except drying saliva when using RMGIC). On RMGIC, re-etching and rinsing–drying methods might provide sufficient SBS levels. All treatments (except rinsing–drying saliva contamination) did not produce appropriate SBS levels when using SEP–composite.ConclusionsBlood contamination reduced the SBS much greater than saliva. Using etchant–RMGIC is strongly recommended. Drying may only suffice when RMGIC is used over saliva contamination. The efficacy of re-etching depends on the etchant type. Rinsing–drying may produce appropriate SBS levels.     

Saliva collection methods for DNA biomarker analysis in oral cancer patients

Patients with head and neck cancers are predisposed to local recurrence and second primaries because of the phenomenon of field cancerisation, and clinical detection of recurrence remains challenging. DNA biomarkers in saliva may prove to be an adjunct to current diagnostic methods, but irradiation of the primary site often leads to xerostomia. We assessed 3 methods of collecting saliva for their ability to generate DNA of sufficient quantity and quality to use in biomarker assays. Paired saliva samples were collected from 2 groups of patients with oral squamous cell carcinoma (SCC). In the first group saliva was collected in Oragene^® vials and as saline mouthwash from non-irradiated patients (n = 21) (4 had had radiotherapy before collection); in the second group it was collected using Oragene^® sponge kits and as mouthwash from irradiated patients (n = 24). Quantitative polymerase chain reaction (qPCR) showed that Oragene^® vials contained DNA in significantly greater amounts (median 122 μg, range 4–379) than mouthwash (median 17 μg, range 2–194) (p = 0.0001) in the non-irradiated patients, while Oragene^® sponge kits (median 4 μg, range 0.1–61) and mouthwash (median 5.5 μg, range 0.1–75) generated comparable concentrations of DNA from the irradiated group. All 90 samples contained DNA of sufficient quantity and quality for p16 promoter quantitative methylation-specific PCR (qMSP). While Oragene^® vials contained the most DNA, all 3 methods yielded enough to detect DNA biomarkers using qMSP. The method of collection should depend on the compliance of the patient and oral competency.     

Kinetics of fluoride bioavailability in supernatant saliva and salivary sediment

The assessment of the fluoride kinetics in whole saliva as well as in the different salivary phases (supernatant saliva and sediment) is essential for the understanding of fluoride bioavailability.ObjectivesTo assess the fluoride content, provided by sodium fluoride and amine fluoride, in the supernatant saliva and in salivary sediment.MethodsSeven trained volunteers were randomly attributed to 2 groups in a cross-over design and brushed their teeth in the morning for 3 min with a product containing either sodium fluoride or amine fluoride. Saliva was collected before, immediately after tooth brushing and 30, 120, and 360 min later and measured. The samples were centrifuged 10 min at 3024 × g. Fluoride content of the supernatant saliva and of the sediment was analysed using a fluoride sensitive electrode. All subjects repeated the study cycles 2 times, and statistical analyses were made using the nonparametric sign test for related samples, the Wilcoxon–Mann–Whitney-test for independent samples.ResultsThere was a significant increase in fluoride immediately after tooth brushing in both groups in saliva and sediment. The distribution of fluoride between salivary sediment and supernatant saliva (ratio) varied considerably at the different collection times: decreased from 17.87 in baseline samples of saliva to 0.07 immediately and to 0.86 half an hour after tooth brushing in the sodium fluoride group and from 14.33 to 2.85 and to 3.09 in the amine fluoride group. Furthermore after 120 min and after 360 min after tooth brushing the ratio increased from 17.6 to 31.6 in the sodium fluoride group and from 20.5 to 25.76 in the amine fluoride group. No difference was found in the sediment–supernatant saliva ratio between the sodium fluoride and the amine fluoride groups 360 min after tooth brushing.ConclusionFor the assessment of fluoride kinetics in whole saliva it is necessary to pay attention to at least four factors: fluoride formulation, time after fluoride application, fluoride concentration in supernatant saliva and fluoride concentration in salivary sediment. This study was approved by the Ethical Committee of the University of Witten/Herdecke permission 21/2008.     

In vivo bisphenol-A release from dental pit and fissure sealants: A systematic review

ObjectiveTo search the literature and assess the short- and long-term release of bisphenol-A (BPA) in human tissues after treatment with dental sealants.DataTwo review authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion with an arbiter.SourcesElectronic database searches of published and unpublished literature were performed. The following electronic databases with no language and publication date restrictions were searched: MEDLINE (via Ovid and Pubmed), EMBASE (via ovid), Cochrane Trials Register and CENTRAL. The reference lists of all eligible studies were hand-searched.Study selectionIn the absence of RCTs, six interventional and two observational studies, examining in vivo BPA release in human salivary, blood and urinary samples, were included. Due to the heterogeneity in methodology and reporting, the main synthesis of the results was qualitative. The quantitative synthesis based on the weighted Z-test could only include two studies. BPA levels identified in saliva ranged from traces below the method's detection limit to 30 μg/ml. In urine, BPA quantities spanned from 0.17 mg/g to 45.4 mg/g. BPA was not traced in any blood sample at any point of time in the relevant studies. The quantitative analysis showed evidence of BPA release one hour after sealant placement compared to the amount traced before restoration (Stouffer's z trend: <0.001).ConclusionsThe available evidence on this topic derived from studies that represent a moderate level of evidence. Nevertheless, the available evidence supports that BPA is released in saliva after sealant placement.Clinical significanceFrom the qualititative and quantitative synthesis of studies, it is reasonable to conclude that BPA is released after placement of some dental pit and fissure sealants in the oral cavity. The biggest quantities are detected in saliva immediately after or one hour after their placement.     

Denaturing gradient gel electrophoresis profiles of bacteria from the saliva of twenty four different individuals form clusters that showed no relationship to the yeasts present

ObjectivesThe aim was to investigate the relationship between groups of bacteria identified by cluster analysis of the DGGE fingerprints and the amounts and diversity of yeast present.MethodsBacterial and yeast populations in saliva samples from 24 adults were analysed using denaturing gradient gel electrophoresis (DGGE) of the bacteria present and by yeast culture.ResultsEubacterial DGGE banding patterns showed considerable variation between individuals. Seventy one different amplicon bands were detected, the band number per saliva sample ranged from 21 to 39 (mean ± SD = 29.3 ± 4.9). Cluster and principal component analysis of the bacterial DGGE patterns yielded three major clusters containing 20 of the samples. Seventeen of the 24 (71%) saliva samples were yeast positive with concentrations up to 10³ cfu/mL. Candida albicans was the predominant species in saliva samples although six other yeast species, including Candida dubliniensis, Candida tropicalis, Candida krusei, Candida guilliermondii, Candida rugosa and Saccharomyces cerevisiae, were identified. The presence, concentration, and species of yeast in samples showed no clear relationship to the bacterial clusters.ConclusionDespite indications of in vitro bacteria-yeast interactions, there was a lack of association between the presence, identity and diversity of yeasts and the bacterial DGGE fingerprint clusters in saliva. This suggests significant ecological individual-specificity of these associations in highly complex in vivo oral biofilm systems under normal oral conditions.     

Increased activity of the antioxidants systems modulate the oxidative stress in saliva of toddlers with early childhood caries

ObjectiveThis study aimed to evaluate the oxidative stress levels and the enzymatic and non-enzymatic antioxidant systems in saliva of toddlers with severe early childhood caries (S-ECC).DesignUnstimulated saliva samples were collected at the morning from 0 to 3 year-old S-ECC (n = 30) or caries-free (CF) children (n = 30/group) for evaluation of oxidative stress (OS) and total antioxidant capacity (TAC), which were measured by the ferric reducing antioxidant power (FRAP) assay, as well as to assess the activity of enzymatic (superoxide dismutase, SOD) and non-enzymatic (uric acid, UA) antioxidant systems, respectively. Data were analyzed by Student’s t-test (p < 0.05).ResultsSignificantly higher protein levels were observed in saliva of S-ECC children (0.083 mg/mL) than in the CF group (0.070 mg/mL). Oxidative damage was significantly lower in saliva of S-ECC children (0.0019 μmol/L/mg protein) than in CF children (0.0039 μmol/L/mg protein), while salivary TAC (61.5 μmol/L), SOD activity (36.6 UE/mL) and uric acid (7.05 mg/mL) were significantly higher in saliva of S-ECC when compared to the CF group (49.1 μmol/L, 26.8 UE/mL and 5.02 mg/mL, respectively for TAC, SOD and UA).ConclusionOxidative stress levels were significantly lower in saliva of S-ECC children, what might be associated with the increased activity of salivary enzymatic (SOD) and non-enzymatic (uric acid) antioxidant systems.     

Resin composite blocks for dental CAD/CAM applications reduce biofilm formation in vitro

ObjectivesModern dentistry is increasingly focusing on digital procedures, including CAD/CAM technologies. New materials have to resist in a demanding environment that includes secondary caries occurrence. The current study hypothesized that the microbiological behavior of different RBCs for CAD/CAM applications is better than that of their counterparts for direct restorations due to differences in the surface characteristics.MethodsBoth direct and CAD/CAM RBCs were tested. Specimens were obtained from each group, polished, cleaned, stored in artificial saliva (1 w), then sterilized under UV (24 h). Specimens’ surface was assessed using profilometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction; resin/filler content was assessed using thermogravimetry. After pre-incubation with sterile human saliva (24 h), the microbiological behavior of the materials was assessed using four models: Streptococcus mutans adherence (2 h), S. mutans biofilm formation in an orbital shaking bioreactor (24 h), S. mutans biofilm formation in a continuous-flow bioreactor simulating shear forces (24 h), and mixed-plaque formation in the bioreactor (24 h). The viable biomass adhering to the specimens’ surfaces was measured using a tetrazolium dye-based test. Statistical analysis included verification of normality of distribution and homoscedasticity, then Oneway ANOVA and Tukey's test (α = 5%).ResultsWhen using the bioreactor setup, CAD/CAM RBCs generally yielded lower S. mutans and mixed-plaque biofilm formation compared to direct RBCs. This difference was not evidenced in the first two microbiological models. Differences in manufacturing and curing processes rather than in materials’ surface roughness and composition could explain these results.SignificanceCAD/CAM RBCs are promising materials from a microbiological point of view, featuring reduced biofilm formation on their surfaces when shear conditions similar to in vivo ones are present.     

The effect of clinical setting on the unstimulated salivary flow rate

ObjectiveUnstimulated whole saliva (UWS) sialometry uses the spitting method to assess occurrence of hyposalivation. This study compares the UWS flow rates in volunteers sitting in a laboratory or in a clinical setting, in order to evaluate the influence of environment on salivary secretion.Design25 healthy volunteers were recruited and divided into two groups to perform UWS sialometry under the two different settings (T1). Eleven weeks later, the participants repeated the same test (T2). At a unique time point and under the clinical setting, 18 patients complaining of xerostomia also performed the UWS sialometry; these values were used as control to corroborate findings.ResultsDifferent scenarios – laboratory one vs. clinical one – did not affect measurements of mean UWS flow rates. Both intra- and inter-individual variabilities, reported as standard error of the mean (SEM) and within-subject variance (WSV), resulted below the threshold of 0.1 g/min. A significant difference was found between UWS flow rates from healthy volunteers and those from patients with xerostomia (p < 0.05). Test/retest reliability showed a moderate correlation of datasets collected at the two time points from healthy volunteers (T1 vs. T2, 11 weeks later): under laboratory and clinical settings, Pearson’s coefficients of correlation were r = 0.62 and r = 0.32, respectively.ConclusionsType of environment did not influence UWS sialometry via spitting method, which appeared reliable for intra-day analysis of the salivary flow rate, although prone to physiological variations over time.     

Quantification of the esthetics of dentists’ before and after photographs

PurposeThe purpose of this study was to measure dentists’ before and after restorative treatment photographs to identify four metrics to describe the esthetic improvement: (a) central incisor width-to-height ratio; (b) central-to-lateral incisor width ratio; (c) lateral incisor-to-canine width ratio; and (d) lateral incisor percentage offset.Materials and methodsInternet searches for “before after” and “veneers” and “prosthodontic” were used to obtain 198 before and after photographs of patient treatments showing the restoration of the six maxillary anterior teeth with porcelain veneers, crowns or a combination. The four metrics were measured using Adobe Photoshop. Groups were compared with repeated measures ANOVA followed by a post hoc Tukey–Kramer test with the variables of “Before or After Treatment”; “Treatment Type” (veneers, crowns or a combination) and “General Dentist or Prosthodontist”.ResultsMean central incisor width-to-height ratio was 91.7% before treatment, 80.8% after; mean central-to-lateral incisor width ratios were 69.9% and 64.7%; mean lateral incisor-to-canine width ratios were 85.3% and 81.4% and lateral incisor percentage offsets were 9.6% and 8.7%. There were significant (p < 0.05) differences for before and after treatment for all variables except central-to-lateral incisor width ratio. Differences between specialist and general dentist were not statistically significant.ConclusionsOn average, esthetic prosthetic treatment resulted in reduced central incisor width-to-height ratio, increased proportional width of the mesially positioned tooth of adjacent anterior teeth and reduced lateral incisor offset. The mean values of treatments by GPs and prosthodontists were not statistically significantly different.Clinical implicationsKnowledge of dentists’ optimal restorative treatments provides insight on the esthetic outcome of extensive prosthodontic therapy.     

Effect of topical application of fluoride gel NaF 2% on enzymatic and non-enzymatic antioxidant parameters of saliva

ObjectiveThe aim of the study was to evaluate the effect of topical fluoride gel NaF 2% application on antioxidant parameters of whole saliva from children.DesignThe saliva mechanically stimulated with parafilm was collected from 25 children (6–12 years) attending the Clinic of Paediatric Dentistry of Universidade Cruzeiro do Sul, São Paulo, Brazil, before (control group) and immediately after application of neutral fluoride gel NaF 2% (fluoride-gel group), according to the Standards for Research Using Human Subjects, Resolution 196/96 of the USA National Health Council of 10/10/1996. Afterwards, pre-post ferric-reducing antioxidant power (FRAP), trolox-equivalent antioxidant capacity (TEAC), uric acid, reduced/oxidised glutathione content (GSH/GSSG) and total peroxidase activity (TPO) were evaluated in whole saliva of both groups.ResultsAll non-enzymatic antioxidant parameters were augmented by fluoride-gel NaF 2% application, whereas a notable reduction (31%) of peroxidase activity was concomitantly observed in the children's saliva (p ≤ 0.05). Nevertheless, the reducing power of saliva was kept unaltered under these circumstances (p ≤ 0.05).ConclusionsDespite the reduced activity of peroxidase (an important antimicrobial and antioxidant enzyme), the topical fluoride gel NaF 2% favourably stimulated the release of non-enzymatic antioxidant components of saliva, sustaining the reducing power of saliva and the natural defences of the oral cavity.     

Does green tea consumption improve the salivary antioxidant status of smokers?

Objective Considering the higher rate of oral cancer, and reduction in salivary antioxidants in smokers as indicated in previous studies, antioxidant- containing nutrients such as green tea, seem to be beneficial in counteracting against oxidative stress in this group. This study assessed the salivary total antioxidant alteration in smokers compared to nonsmokers, after short-tem (7 days) and long-term (3 weeks), green tea drinking.DesignIn this experimental study, 20 volunteer moderate-to-heavy male smokers, and 20 matched healthy non-smokers were selected to participate, according to the inclusion criteria. Participants were instructed to drink two cups of green tea per day, by dissolving 2 g of green tea in 150 ml of hot water for each cup. After saliva collection, antioxidant capacity of saliva was measured at baseline, after 7 days, and after 21 days. Statistical evaluation was done by SPSS 21, using paired samplet tests, one-way ANOVA and Bonferroni tests.Results At day zero nonsmokers had a higher antioxidant capacity than smokers (686.6 ± 62.22 vs. 338.8 ± 59.9) mM/50 μl, P < 0.001. There was also a significant difference between two groups in salivary total antioxidant capacity after one week and three weeks of green tea consumption (P < 0.001). However, there was an upward trend in both smokers and non-smokers over the study period (after tea drinking). In addition, a significant difference was found in total antioxidant capacity alteration in smokers compared to non-smokers from baseline to day 21.ConclusionsResults support the effectiveness of green tea consumption in salivary antioxidants enhancement in smokers, in both the short- and long term.     

Nickel and chromium levels in the saliva of a Saudi sample treated with fixed orthodontic appliances

AimThe aim of this study was to measure the amount of nickel (Ni) and chromium (Cr) released into the saliva of Saudi patients treated with fixed orthodontic appliances.Materials and methodsNinety salivary samples were collected in a cross-sectional manner. Forty samples were collected from patients (17 males, 23 females) with fixed orthodontic appliances after different periods of orthodontic treatment ranging from the first month and up to 32 months into treatment. The fixed orthodontic appliance consisted of 4 bands, 20 stainless steel brackets, and upper and lower nickel titanium or stainless-steel arch wires. The other 50 samples were collected from people without appliances (24 males, 26 females). Samples were analyzed using Inductive Coupled Plasma/Mass Spectrometry and Inductively Coupled Plasma Optical Emission Spectroscopy to measure Ni and Cr levels, respectively. Student’s t-test was used to compare Ni and Cr levels in the treated and untreated control groups.ResultsThe mean Ni level was 4.197 μg/L in the experimental group and 2.3 μg/L in the control group (p < 0.05). The mean Cr level was 2.9 μg/L in the experimental group and 3.3 μg/L in the control group (p < 0.05).ConclusionFixed orthodontic appliances resulted in a non-toxic increase in salivary levels of Ni, but no change in Cr levels. Duration of orthodontic treatment did not affect Ni and Cr levels in the saliva.     

Effects of dual antibacterial agents MDPB and nano-silver in primer on microcosm biofilm,cytotoxicity and dentine bond properties

ObjectivesThe objective of this study was to investigate the effects of dentine primer containing dual antibacterial agents, namely, 12-methacryloyloxydodecylpyridinium bromide (MDPB) and nanoparticles of silver (NAg), on dentine bond strength, dental plaque microcosm biofilm response, and fibroblast cytotoxicity for the first time.MethodsScotchbond Multi-Purpose (SBMP) was used as the parent bonding agent. Four primers were tested: SBMP primer control (referred to as “P”), P + 5% MDPB, P + 0.05% NAg, and P + 5% MDPB + 0.05% NAg. Dentine shear bond strengths were measured using extracted human teeth. Biofilms from the mixed saliva of 10 donors were cultured to investigate metabolic activity, colony-forming units (CFU), and lactic acid production. Human fibroblast cytotoxicity of the four primers was tested in vitro.ResultsIncorporating MDPB and NAg into primer did not reduce dentine bond strength compared to control (p > 0.1). SEM revealed well-bonded adhesive–dentine interfaces with numerous resin tags. MDPB or NAg each greatly reduced biofilm viability and acid production, compared to control. Dual agents MDPB + NAg had a much stronger effect than either agent alone (p < 0.05), increasing inhibition zone size and reducing metabolic activity, CFU and lactic acid by an order of magnitude, compared to control. There was no difference in cytotoxicity between commercial control and antibacterial primers (p > 0.1).ConclusionsThe method of using dual agents MDPB + NAg in the primer yielded potent antibacterial properties. Hence, this method may be promising to combat residual bacteria in tooth cavity and invading bacteria at the margins. The dual agents MDPB + NAg may have wide applicability to other adhesives, composites, sealants and cements to inhibit biofilms and caries.     

Adhesive class I restorations in sound molar teeth incorporating combined resin-composite and glass ionomer materials: CAD-FE modeling and analysis

ObjectivesTo investigate the influence of different resin composite and glass ionomer cement material combinations in a “bi-layer” versus a “single-layer” adhesive technique for class I cavity restorations in molars using numerical finite element analysis (FEA).Materials and MethodsThree virtual restored lower molar models with class I cavities 4 mm deep were created from a sound molar CAD model. A combination of an adhesive and flowable composite with bulk fill composite (model A), of a glass ionomer cement with bulk fill composite (model B) and of an adhesive with bulk fill composite (model C), were considered. Starting from CAD models, 3D-finite element (FE) models were created and analyzed. Solid food was modeled on the occlusal surface and slide-type contact elements were used between tooth surface and food. Polymerization shrinkage was simulated for the composite materials. Physiological masticatory loads were applied to these systems combined with shrinkage. Static linear analyses were carried out. The maximum normal stress criterion was adopted as a measure of potential damage.ResultsAll models exhibited high stresses principally located along the tooth tissues–restoration interfaces. All models showed a similar stress trend along enamel–restoration interface, where stresses up to 22 MPa and 19 MPa was recorded in the enamel and restoration, respectively. A and C models showed a similar stress trend along the dentin-restoration interface with a lower stress level in model A, where stresses up to 11.5 MPa and 7.5 MPa were recorded in the dentin and restoration, respectively, whereas stresses of 17 MPa and 9 MPa were detected for model C. In contrast to A and C models, the model B showed a reduced stress level in dentin, in the lower restoration layer and no stress on the cavity floor.SignificanceFE analysis supported the positive effect of a “bi-layer” restorative technique in a 4 mm deep class I cavities in lower molars versus “single-layer” bulk fill composite technique.     

Knowledge about pressure ulcer prevention,classification and management: A survey of registered nurses working with trauma patients in the emergency department

AimOne group of patients who are at risk of pressure ulcer development is trauma patients. The present study aimed to examine trauma nurses’ knowledge about pressure ulcer prevention, classification and management.MethodsIn a cross sectional exploratory study all qualified registered nurses working with trauma patients in the emergency department (ED) of Kashani and Bahonar hospitals, Iran were invited to participate. To assess the nurses’ knowledge about pressure ulcer prevention classification and management Pieper’s Pressure Ulcer Knowledge Test (PPUKT) was used.ResultsOf 185 eligible nurses, 159 participated in the study (response rate of 86%). Of these, 80.5% (n = 128) were women and 19.5% (n = 31) were men. The mean years of nurses’ experience was 10.3 ± 7.2 years. The percentage of correctly answered questions was 64.6%. Nurses had the highest level of knowledge in the section about wound characteristics (77.3%) and the lowest level in the section about pressure ulcer onset (57%).ConclusionThis is the first study that specifically examines trauma nurses knowledge about pressure ulcer prevention, classification and management. According to the results, nurses did not have sufficient knowledge about pressure ulcer prevention, classification and management. There is a need to improve their knowledge with educational programs.     

Is the morphology and activity of the occlusal carious lesion related to the lesion progression stage?

ObjectiveTo investigate the relationship between degree of dentin demineralization with both lesion activity and morphology of the occlusal carious cavity.DesignOcclusal sites (n = 138) were identified by visual examination (Nyvad’s scores 0–6) in 67 extracted teeth which were scanned in a high energy micro-CT. After 3D reconstruction, each stack was resliced in the mesio-distal direction and tooth mineral density (MD) was measured along a path from enamel to the deepest part of dentin in the slice showing the most severe carious involvement. Each site was classified in “open” or “closed” (if cavitated) depending on the morphology of the surrounding enamel walls as measured using micro-CT and as active or inactive in enamel or dentin by a clinical scoring system.ResultsLesions showing dentin cavitation presented higher demineralization degree compared to non-cavitated, or enamel cavitated lesions. Inactive lesions presented lower demineralization degree compared to active lesions, although with a low effect size. According to the morphological aspect of the carious cavity, open enamel lesions showed lower dentin demineralization degree than closed lesion environments.ConclusionActive lesions showed higher dentin demineralization degree than inactive ones, while lesions showing closed cavitation resulted in higher dentin demineralization degree only for enamel lesions. Including those parameters in treatment decisions may help to improve prognosis and increase effectiveness of the caries diagnostic systems in the clinical setting.     

Calcium and phosphate ion releasing composite: Effect of pH on release and mechanical properties

ObjectivesSecondary caries and restoration fracture are the two main challenges facing tooth cavity restorations. The objective of this study was to develop a composite using tetracalcium phosphate (TTCP) fillers and whiskers to be stress-bearing, and to be “smart” to increase the calcium (Ca) and phosphate (PO₄) ion release at cariogenic pH.MethodsTTCP was ball-milled to obtain four different particle sizes: 16.2, 2.4, 1.3, and 0.97 μm. Whiskers fused with nano-sized silica were combined with TTCP as fillers in a resin. Filler level mass fractions varied from 0 to 75%. Ca and PO₄ ion releases were measured vs. time at pH of 7.4, 6, and 4. Composite mechanical properties were measured via three-point flexure before and after immersion in solutions at the three pH.ResultsTTCP composite without whiskers had flexural strength similar to a resin-modified glass ionomer (Vitremer) and previous Ca–PO₄ composites. With whiskers, the TTCP composite had a flexural strength (mean ± S.D.; n = 5) of (116 ± 9) MPa, similar to (112 ± 14) MPa of a stress-bearing, non-releasing hybrid composite (TPH) (p > 0.1). The Ca release was (1.22 ± 0.16) mmol/L at pH of 4, higher than (0.54 ± 0.09) at pH of 6, and (0.22 ± 0.06) at pH of 7.4 (p < 0.05). PO₄ release was also dramatically increased at acidic pH. After immersion, the TTCP–whisker composite matched the strength of TPH at all three pH (p > 0.1); both TTCP–whisker composite and TPH had strengths about threefold that of a releasing control.SignificanceThe new TTCP–whisker composite was “smart” and increased the Ca and PO₄ release dramatically when the pH was reduced from neutral to a cariogenic pH of 4, when these ions are most needed to inhibit caries. Its strength was two- to threefold higher than previously known Ca–PO₄ composites and resin-modified glass ionomer. This composite may have the potential to provide the necessary combination of load-bearing and caries-inhibiting capabilities.     

The concentration of gum component in saliva before and after swallowing during prolonged gum chewing

ObjectivesThe concentration of the substances eluted from the gum into saliva before and after swallowing has not almost carried out. The purpose of this study was to measure the volume of saliva before (VMAX) and after (RESID) swallowing in the mouth and was also to measure the concentration of the component (sugar) eluted from the gum chewing.MethodsThe RESID was measured by a dilution method (Lagerlof and Dawes, 1984). It was computed by measuring the potassium concentration in saliva and in the expectorated after a five-second rinse with 10ml of water immediately following a swallow. The volume swallowed was calculated as salivary flow rate divided by the swallowing frequency, and the VMAX was estimated as the sum of RESID and the volume of saliva swallowed. Swallows were registered by placing over the larynx an electrode which was connected to an EMG. The volume of sugar contained in the gum was 74.8% as a total weight of the gum. Subjects were seven males and 13 females who were all in good health for measuring the RESID and VMAX. For each of the six participants of them, the concentration of sugar in saliva expectorated was measured by frame photometer.ResultsVMAX, swallowing frequency and the volume of fluid swallowed increased as comparing with the values when the salivary flow rate was unstimulated. The mean volume of sugar in expectorated saliva as a percentage of the initial weight of sugar contained during gum chewing at the first swallowing was 16.5 ± 5.38% and at the 10th swallowing was 0.76 ± 0.06%. These were 3.6 times and 1.8 times of those of unstimulated saliva, respectively.