Search

The article presents an answer to a question on the use of ozone in root canal therapy.

The article provides an answer to a question about the use of ozone as a means of caries treatment.

Washington''s relationships with the “leveraged allies” preferred by realists—those countries that have little choice but to follow America''s lead—have long been considered more reliable than in its relationships with the “natural allies” favored by idealists: prosperous, democratic nations that share the goals and interests of the United States. President Bush''s foreign policy requires these natural allies, but many U.S. government officials are more wary. Uganda under President Museveni is a model “natural ally” candidate, with its relatively humane and democratic internal policies, but its greater capacity to act without American leverage, approval, or supervision is likely to worry realist career diplomats. [Copyright &y& Elsevier]

This preregistered ex vivo investigation examined the dentinal hybrid layer formation of a resinous infiltrant (Icon), with reference to both thickness (HLT) and homogeneity when combined with modified tunnel preparation (occlusal cavity only) and internal/external caries infiltration. The adhesives Syntac and Scotchbond MP were used as controls (Groups 1 and 3) or in combination with Icon (Groups 2 and 4). A split-tooth design using healthy third molars from 20 donors resulted in 20 prepared dentine cavities per experimental group. The cavity surfaces (n = 80) were etched (37% H3PO4), rinsed, and air-dried. Rewetting with ethanol was followed by application of the respective primers. After labeling with fluorescent dyes, either Syntac Adhesive/Heliobond or Scotchbond MP Adhesive was used alone or supplemented with Icon. HLT, as evaluated by scanning electron microscopy, did not significantly differ (P > 0.05), and confocal laser scanning microscopy revealed homogeneously mixed/polymerized resin-dentine interdiffusion zones in all groups. Icon can be successfully integrated into an ethanol-wet dentine bonding strategy, and will result in compact and homogeneous hybrid layers of comparable thickness considered equivalent to the non-Icon controls, thus allowing for preservation of the tooth's marginal ridge and interdental space in the case of internal/external infiltration of proximal caries. [ABSTRACT FROM AUTHOR]

This study aimed to assess the knowledge regarding impacts, causes and management of black triangles (BT) among participants from different educational backgrounds including dental students, dentists and laypeople. This descriptive cross-sectional observational research included 435 participants who comprised 4 groups: pre-clinical (3rd year) dental students, clinical (4th and 5th year) dental students, dentists, and laypeople. A constructed self-reported questionnaire was utilized to assess participants' demographic data and their knowledge of the impacts, causes and management of BT. The VAS scale was used to assess participants' ratings for the impacts of BT on esthetics, with 0 meaning no impact and 10 meaning very severe negative impacts. The most reported treatments for BT were "cannot be treated" 99.3% and "non-surgical periodontal treatment" 67.1%. Meanwhile, the least reported was "modify the porcelain" 41.8%. The most reported cause of BT was "periodontal disease" 85.1%. However, the least reported were "parafunction" and "deep implants" 33.1% each. Dental professionals had better knowledge of the causes (t = 8.189, P < 0.001) and management (t = 8.289, P < 0.001) of BT than the non-dental participants. The dentists had the best knowledge, while the laypeople had the least knowledge of the causes (F = 62.056, P < 0.001) and treatment (F = 46.120, P < 0.001) of BT. The knowledge of the causes (t = 0.616, P = 0.538) and treatment (t = 1.113, P = 0.266) for BT was not significantly different between males and females. Age was not significantly related to the total knowledge about the causes (r = −0.034, P = 0.475) or treatment (r = −0.034, P = 0.482) for BT. Dental professionals had better knowledge of the impacts, causes and management of BT than the non-dental participants. The dentists were the best, while the laypeople were the worst in this regard. Age and gender had no relationships with the knowledge of causes or management of BT. [ABSTRACT FROM AUTHOR]

Focuses on the influence of religion on political reforms in Latin America in the 20th century. Procapitalist leanings of the Catholic Church since the 1900s; Rejection of democracy and capitalism by liberation theologists; Confusion of Catholic social thoughts among evangelical Protestants; Opportunities for political collaboration between the evangelicals and Catholics.

Explores the impact of Catholic social thought on the Latin America's politics and economy. Analysis of party types in Latin America as useful predictor of the future of economic reform and democratization; Economic elements of Catholic social thought; Chilean success story; Venezuelan Christian Democrats' failure to learn from their Chilean counterparts.

Comments on the National Commission on Public Service's report on the state of civil service in the United States. Political appointees' impact on civil service; Commission's recommendations on how to improve the civil service.

This analytical cross-sectional study evaluated the perception of black triangles (BT) and examined the relationships between the perception of BT, personality factors, different educational backgrounds and demographic factors. 435 participants were included and divided into four groups: dentists, clinical (4th and 5th year) dental students, pre-clinical (3rd year) dental students, and laypeople. Participants' perception of the attractiveness of smile profiles of maxillary and mandibular anterior dentition with BT was rated using a ten-point VAS scale with 0 being the least, and 10 being the most attractive smile profile. The personality was assessed using the NEO-FFI personality questionnaire. The smile profile with multiple large BT was rated the least attractive for the maxillary (mean = 3.6) and mandibular (mean = 3.9) tested profiles. The smile profile without BT was rated the most attractive for the maxillary (mean = 9.1) and mandibular (mean = 8.8) tested profiles. The dental professionals perceived the maxillary smile profile with multiple large BT as less attractive than the non-dental participants (t = − 2.715, P = 0.007). Being a male, having dental education, having lower Neuroticism scores, as well as having higher Openness, Agreeableness, Conscientiousness, and Extraversion scores predicted and contributed more towards perceiving various tested smile profiles as more attractive. These findings show that black triangles negatively impacts the perception of smile attractiveness, and that personality traits and having dental education impact the perception of smile attractiveness for smiles with black triangles. [ABSTRACT FROM AUTHOR]

This article focuses on bilateral idiopathic root resorption of upper first premolars. Internal resorption is an unusual form of tooth resorption initiated within the pulp cavity. The resorption may be a slow progressive process extending over one or more years or it may develop rapidly and perforate the tooth within a matter of months. The condition is often painless and is revealed by radiographic examination as a more or less expansive, radiolucent area within the tooth, that is usually clearly delineated.

Introduction: Intimal sarcoma of the pulmonary artery is a rare and aggressive tumor. We present a case of a high-grade primary pulmonary artery intimal sarcoma with extended patient survival status post pneumonectomy. Methods: The patient was a 59-year-old man who presented with worsening dyspnea. Imaging demonstrated a large mass within the right pulmonary artery, with high avidity on PET scan, suspicious for tumor. A right pneumonectomy was performed. The right lung was received with 7 cm of pulmonary artery attached. Obstructing the entire length of artery was a fleshy, white-tan mass with focal attachment to the arterial wall. The specimen was serially sectioned, revealing the mass to consist of heterogeneously soft to fibrous tissue and focally hemorrhagic regions, with significant retrograde extension into the peripheral pulmonary circulation. Histologic examination revealed predominantly spindle-shaped and pleomorphic cells without evidence of specific differentiation, in a background of variably fibrillar, myxoid and fibrous stroma. The tumor arose from the intima of the pulmonary artery, with invasion through the wall and into the adjacent pulmonary vein, as well as into the peripheral parenchyma. Extensive necrosis was noted, as were numerous and occasionally bizarre mitotic figures. An extensive immunohistochemical panel was performed, but was nonspecific. The morphology and growth pattern were most consistent with a primary intimal sarcoma of the pulmonary artery. Conclusions: Intimal sarcoma of the pulmonary artery is a rare and lethal disease, with a one-year mortality rate of 80%. Surgery is the mainstay of treatment, with one case series indicating that evidence of invasive disease renders the patients inoperable and requiring chemoradiotherapy. Our patient is alive and disease free after an interval of approximately 27 months, possibly demonstrating that surgery for invasive disease can offer a survival benefit. [ABSTRACT FROM AUTHOR]

An approximately 90 km long Palaeoproterozoic supracrustal belt in the northwestern Norrbotten ore province (northernmost Sweden) was investigated to characterize its structural components, assess hydrothermal alteration–structural geology correlations, and constrain a paired deformation–fluid flow evolution for the belt. New geological mapping of five key areas (Eustiljåkk, Ekströmsberg, Tjårrojåkka, Kaitum West, and Fjällåsen–Allavaara) indicates two major compressional events (D1 and D2) have affected the belt, with each associated with hydrothermal alteration types typical for iron oxide–apatite and iron oxide Cu–Au systems in the region. Early D1 generated a regionally distributed, penetrative S1 foliation and oblique reverse shear zones that show a southwest-block-up sense of shear that formed in response to NE–SW crustal shortening. Peak regional metamorphism at epidote–amphibolite facies broadly overlaps with this D1 event. Based on overprinting relationships, D1 is associated with regional scapolite ± albite, magnetite + amphibole, and late calcite alteration of mafic rock types. These hydrothermal mineral associations linked to D1 structures may form part of a regionally pervasive evolving fluid flow event but are separated in this study by crosscutting relationships. During D2 deformation, folding of S0 – S1 structures generated F2 folds with steeply plunging fold axes in low-strain areas. NNW-trending D1 shear zones experienced reverse dip-slip reactivation and strike-slip-dominated movements along steep, E–W-trending D2 shear zones, producing brittle-plastic structures. Hydrothermal alteration linked to D2 structures is a predominantly potassic–ferroan association comprising K-feldspar ± epidote ± quartz ± biotite ± magnetite ± sericite ± sulfides. Locally, syn- or post-tectonic calcite is the main alteration mineral in D2 shear zones that intersect mafic rocks. Our results highlight the importance of combining structural geology with the study of hydrothermal alterations at regional to belt scales to understand the temporal–spatial relationship between mineralized systems. Based on the mapping results and microstructural investigations as well as a review of earlier tectonic models presented for adjacent areas, we suggest a new structural model for this part of the northern Fennoscandian Shield. The new model emphasizes the importance of reactivation of early structures, and the model harmonizes with tectonic models presented by earlier workers based mainly on petrology of the northern Norrbotten area. [ABSTRACT FROM AUTHOR]

In this field-based study, a ~ 90 km long Palaeoproterozoic metasupracrustal belt in the northwestern part of the Norrbotten ore province (northernmost Sweden) has been investigated in order to characterize its various structural components and thus constrain its structural evolution. In addition, hydrothermal mineral associations are described and linked to identified deformation phases. New geological mapping of five key areas (Eustiljåkk, Ekströmsberg, Tjårrojåkka, Kaitum West and Fjällåsen-Allavaara) indicates two major compressional events (D1, D2) that affected the belt whereas each deformation event can be related to specific alteration styles typical for iron oxide-apatite and iron oxide Cu-Au systems. D1 generated a regionally distributed penetrative S1 foliation and oblique reverse shear zones with southwest block up sense-of-shears in response to NE-SW crustal shortening. D1 is associated with regional scapolite ± albite alteration formed coeval with regional magnetite ± amphibole alteration and calcite under epidote-amphibolite metamorphism. During D2, folding of S1 generated steeply south-plunging F2-folds in low strain areas whereas most strain was partitioned into pre-existing shear zones resulting in reverse dip-slip reactivation of steep NNW-oriented D1 shear zones and strike-slip dominated movements along steep E-W-trending shear zones under brittle-ductile conditions. The hydrothermal alteration linked to the D2 deformation phase is more potassic in character and dominated by K-feldspar ± epidote ± quartz ± biotite ± magnetite ± sericite ± sulphides, and calcite. Our results underline the importance of paired structural-alteration approaches at the regional- to belt-scale to understand the temporal-spatial relationship between mineralized systems. Based on the mapping results and microstructural investigations, as well as a review of earlier tectonic models presented for adjacent areas, we suggest a new structural model for this part of the northern Fennoscandian Shield. Our new structural model harmonizes with earlier petrological/geochemical tectonic models of the northern Norrbotten area and emphasizes the importance of reactivation of early formed structures. [ABSTRACT FROM AUTHOR]

Nanoparticles (NPs) are insoluble particles smaller than 100 nm in size. In order to prevent microbial adhesion or enamel demineralization in orthodontic therapy, two broad strategies have been used. These are incorporating certain NPs into orthodontic adhesives/cements or acrylic resins (nanofillers, silver, TiO2, SiO2, hydroxyapatite, fluorapatite, fluorohydroxyapatite) and coating surfaces of orthodontic appliances with NPs (i.e. coating bracket surfaces with a thin film of nitrogen-doped TiO2). Although the use of NPs in orthodontics can offer new possibilities, previous studies investigated the antimicrobial or physical characteristic over a short time span, i.e. 24 hours to a few weeks, and the limitations of in vitro studies should be recognized. Information on the long-term performance of orthodontic material using nanotechnology is lacking and necessitates further investigation and so do possible safety issues (toxicity), which can be related to the NP sizes. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCA and K-means clustering are separately useful for the interpretation and classification of multivariate geochemical data. • It has significant potential for undiscovered Li mineralization in Västernorrland based on the results of PCA and K-means clustering. • Expert knowledge must be involved in the selection of variables and estimation of the optimal numbers of clusters. • Till geochemical data were useful for identification of potential area in Västernorrland, Sweden. To achieve the demand for elements used for the green transition energy, such as lithium, it is necessary to recognize the spatial distribution of the concentrations of these elements in different earth materials such as bedrock and soil and to identify areas with anomalous concentrations of such elements (i.e., mineralization) for further exploration and hopefully exploitation. This study carried out multivariate statistical analyses on compositional (i.e., element concentration) data from till samples to recognize areas that likely contain lithium pegmatite mineralization in the Västernorrland region, central Sweden. We applied principal components analysis (PCA) and K-means clustering techniques to reveal regional-scale patterns in the till geochemical data. We demonstrate that these two methods have potential for recognition of geochemical anomalies related to the underlying bedrock geology as well as to mineralization. The results of PCA- and K-means clustering were validated using known occurrences of lithium mineralization. Two different datasets were compared; one containing all available geochemical data and the second containing only available trace elements in the dataset and it was found that anomalous clusters of samples defined by K-means clustering have anomalous multi-element signatures defined by robust PCA. This demonstrated that principal components are the continuous solutions to the discrete cluster members for the K-means clustering. The results show that both PCA and K-means clustering of till geochemical datasets at the early stages of exploration and target generation may reveal useful information that can be used to identify potential areas for more detailed mapping or exploration activities. [ABSTRACT FROM AUTHOR]

Background. A multicomponent evaluation of the oxidative consumption of salivary biomolecules by a tooth-whitening oral rinse preparation has been performed using high-resolution proton (1H) nuclear magnetic resonance spectroscopy (NMR). Methods. Unstimulated human saliva samples ( n = 12) were treated with aliquots of the oral rinse tested and 600 MHz 1H NMR spectra acquired on these samples demonstrated that hydrogen peroxide (H2O2) and/or peroxodisulphate (S2O8 2-) present in this product gave rise to the oxidative decarboxylation of the salivary electron-donor pyruvate (to acetate and CO2), and also oxidized methionine (a precursor to volatile sulphur compounds responsible for oral malodour), and malodourous trimethylamine to methionine sulphoxide and trimethylamine-N-oxide, respectively (reductions observed in the salivary concentrations of each biomolecular peroxide-scavenging agent were all extremely statistically significant, p < 0.005). Results. Experiments conducted on chemical model systems confirmed the consumption of pyruvate by this product, and also revealed that the amino acids cysteine and methionine were oxidatively transformed to cystine and methionine sulphoxide, respectively. Conclusions. High-field 1H NMR analysis provides much valuable molecular information regarding the fate of tooth-whitening oxidants in human saliva and permits an assessment of the mechanisms of action of oral healthcare products containing these agents. The biochemical and potential therapeutic significance of the results obtained are discussed. [ABSTRACT FROM AUTHOR]

Hydrogen peroxide (H2O2) is a powerful oxidising agent. It gives rise to agents known to be effective bleaching agents. The mechanisms of bleaching involve the degradation of the extracellular matrix and oxidation of chromophores located within enamel and dentin. However, H2O2 produces also local undesirable effects on tooth structures and oral mucosa. In clinical conditions, the daily low-level doses used to produce tooth whitening never generate general acute and sub-acute toxic effects. Genotoxicity and carcinogenicity only occur at concentrations that are never reached during dental treatments. Some transient adverse effects have been reported on the oral mucosa and the digestive tract if the product is swallowed. Local effects may occur on the oral mucosa and dental tissues during whitening, namely, pulp sensitivity, cervical resorption, release of selected components of dental restorative materials, and alteration of the enamel surface. Most of the local effects are dependent of the technique and concentration of the product so far used, but as the results of bleaching obtained are not stable, repeated treatments add to the adverse effects. The informed decision to administer or not and the control of bleaching effects should stand in the hand of dental surgeons and certainly not as it appears at present, as cosmetics sold without any restriction despite the potential health hazards of peroxides. [ABSTRACT FROM AUTHOR]

High resolution proton (^{1}H) nuclear magnetic resonance (NMR) spectroscopy was employed to simultaneously evaluate the oxidising actions of ozone (O_{3}) towards a wide range of salivary biomolecules in view of its applications in dental practices, which may serve as a viable and convenient means for the treatment of dental caries. Treatment of supernatants derived from unstimulated human saliva specimens (n=12) with O_{3} (4.48 mmol) revealed that this reactive oxygen species gave rise to the oxidative consumption of pyruvate (generating acetate and CO_{2} as products), lactate (to pyruvate and sequentially acetate and CO_{2}), carbohydrates in general (a process generating formate), methionine (giving rise to its corresponding sulphoxide), and urate (to allantoin). Further, minor O_{3}-induced modifications included the oxidation of trimethylamine and 3-D-hydroxybutyrate, the fragmentation of salivary glycosaminoglycans to NMR-detectable saccharide fragments, and the conversion of polyunsaturated fatty acids to their ozonides. Moreover, evidence for the ability of O_{3} to induce the release of selected low-molecular-mass salivary biomolecules from macromolecular binding-sites was also obtained. Since many of the oxidation products detectable in O_{3}-treated samples are identical to those arising from the attack of ^{&bullet;}OH radical on biofluid components, it appears that at least some of the modifications observed here are attributable to the latter oxidant (derived from O_{3}^{&bullet;-} generated from the single electron reduction of O_{3}). [ABSTRACT FROM AUTHOR]

Objective. The objective of this study was to determine the candidal load of the patients with Chronic Obstructive Pulmonary Disease (COPD) and evaluate the oral health status of subjects with COPD. Material and Methods. N = 112 COPD subjects and N = 100 control subjects were included in the study. The selection of COPD cases was confirmed based on the set criteria from the American College of Physicians. The oral health status was assessed as per WHO criteria to determine the score of decayed, missing, and filled teeth (DMFT), significant caries index (SiC), community periodontal index and treatment needs (CPITN), and oral hygiene index-simplified (OHI-S). Gram staining was performed to identify Candida using the whole saliva. Quantitative evaluation of the candidal load was carried out using Sabouraud Dextrose Agar (SDA). Chrome agar was used to differentiate between the commensal carriages. A statistical analysis paired t -test and 95% confidence interval (CI) for proportions was carried out using STATA software. Results. Candidal growth was found in 21.42% (n = 24) of COPD cases and 1.1% (n = 11) of control cases (p < 0.05) (95% CI 0.45, 0.59). The DMFT score was 8.26 in COPD subjects and 4.6 in controls, the SiC score was 16.42 in COPD subjects and 10.25 in controls, and the CPITN score for both COPD and control cases was score 2. Conclusion. In conclusion, there was a higher candidal load among subjects suffering from COPD. Theophylline medication can be a risk factor for increased candidal load in COPD patients. [ABSTRACT FROM AUTHOR]

Abstract Aim, background: Oral malodour (halitosis) is generally ascribable to oral microbial putrefaction generating malodorous volatile sulphur compounds which predominantly comprise dihydrogen sulphide and methyl mercaptan. This study assesses the relative effectiveness of 6 oral health care products in reducing oral cavity volatile sulphur compound concentrations. Method: A mixed model 3-factor factorial experimental design involving 6 volunteers, 7 treatment regimens (products I–VI* and water placebo) and 5 time-points (0.00–5.29 h) was undertaken. Electron-donating volatile sulphur compound levels were determined in triplicate using a sulphide monitor (Interscan model 1170) both prior to (0.00 h) and following oral rinsing (20 ml of 5 of the products) or chewing (2 capsules of the remaining product) episodes with each product examined (0.29, 1.29, 2.29 and 5.29 h post-administration). Results: Results were recorded as peak and steady-state volatile sulphur compound equivalents (ppb). With the exception of one of the products, each oral health care product tested was found to reproducibly reduce volatile sulphur compound concentrations within 20 min of treatment; the mean % decreases in peak (and corresponding steady-state) levels ranging from 3.6 (0.0) to 16.8 (16.4)%. Subsequently, volatile sulphur compound concentrations returned to their zero-control (baseline) values within 5 h, the rate of this regression being in the reverse of the order observed for the magnitude of the primary 20 min reduction for both peak and steady-state measurements. As expected, the water placebo exerted no influence on oral cavity volatile sulphur compound levels. The most effective oral health care products contained admixtures of chlorite anion and chlorine dioxide (both of these agents have the ability to directly oxidise volatile sulphur compounds to non-malodorous products and the latter is also powerfully cidal towards odourigenic micro-organisms). Conclusions: We therefore conclude that oral health care products containing such oxohalogen oxidants may provide a useful therapeutic strategy for the treatment of oral malodour. [ABSTRACT FROM AUTHOR]

The aim of this controlled randomized crossover study was to assess post-treatment pain and the need for root canal treatment after the use of a traditional caries removal method followed by restoration, or after an ozone method of more conservatively managing the deep caries and a restoration. 84 participants (42 males and 42 females, mean age ± SD = 23.9 ± 2.0 years) were randomly allocated to receive either a traditional (n = 42, 21 males and 21 females) or ozone (n = 42, 21 males and 21 females) method. The ozone method only differed from the traditional method by leaving the deep leathery caries on the pulpal floor and then treating this with 20 s of ozone from the healozone X4 (Curozone, Germany). All caries was removed in the traditional group. A conventional glass ionomer cement (Riva Self Cure High Viscosity, SDI, Australia) was placed followed by a bonded composite resin restoration (Filtek Z250 Universal Restorative, 3 M ESPE, USA) in each cavity. The visual analogue scale was used to assess pain scores before treatment and after 24 h. The participants were then followed up for 2 years to assess the need for root canal treatment. Statistical significance levels were set at α ≤.05. Both groups were associated with significant reduction of pain scores 24 h after treatment (p <.0001). The ozone treatment was associated with less pain 24 h after treatment (p <.0001) and less need for root canal treatment (p =.014), after 2 years follow up, than the conventional treatment. In conclusion, treatment of symptomatic, deep carious lesions by ozone following partial removal of caries was accompanied with less pain and occurrence of RCT after treatment compared to traditional complete caries removal. [ABSTRACT FROM AUTHOR]

A petrographic investigation of ore samples from the Assarel porphyry copper deposit in the Srednogorie metallogenic zone (Bulgaria) constrains the setting and character of precious metals (Au, Ag, PGE) and related minerals within the deposit. This work supports renewed interest in understanding the deportment of precious metals and provides mineralogical knowledge during the testing and validation of novel drill core 3D X-ray computed tomography–X-ray fluorescence (XCT-XRF) scanning technology being developed as part of the X-MINE project. Scanning electron microscopy–energy dispersive spectrometry (SEM-EDS) results indicate precious metals occur in their native state (Au, Ag), as sulfides (Ag), sulfosalts (Au), tellurides (Ag, Pd), and selenides (Ag), and typically form micron-sized inclusions in pyrite and chalcopyrite or are disseminated in the groundmass of the rock. Preservation of early Fe oxide–chalcopyrite ± bornite assemblage as relics in the more dominant pyrite-chalcopyrite mineralization assemblage supports mineral disequilibrium relationships and multi-stage mineralization events. Several rare minerals (e.g., merenskyite, acanthite, sorosite, tetra-auricupride, auricupride, greenokite, bismuthinite, nagyagite, native Ni) are reported for the first time at Assarel and highlight the mineralogical diversity of the ore. The occurrence of precious metals and related minerals at Assarel attest to a complex hydrothermal system that underwent progressive physicochemical changes during the evolution of the mineralizing system (e.g., redox conditions, fluid chemistry). [ABSTRACT FROM AUTHOR]

Objective: To explore via systematic review the validation of uneventful post-surgical healing, associated with shorter and longer laser wavelength applications in minor oral surgery procedures. Methods: From April 28 to May 11, 2020, PubMed, Cochrane Database of Systemic Reviews, and Google Scholar search engines were applied to identify human clinical trials of photobiomodulation (PBM) therapy in clinical dentistry. The searches were carried out with reference to (1) dental laser wavelengths shorter than 650 nm; (2) wavelengths localized within the 2780-2940 nm; and (3) the 9300-10,600 nm range. Selected articles were further assessed by three independent reviewers for strict compliance with PRISMA guidelines and modified Cochrane Risk of Bias to determine eligibility. Results: Using selection filters of randomized clinical trials, moderate/low risk of bias, and the applied period, and following PRISMA guidelines, 25 articles were selected and examined. A risk of bias was completed, where 11 out of 25 publications were classified as low risk of bias, and 14 out of 25 were classified as medium risk status. In total, 6 out of 13 (46% of ) studies comparing the examined laser wavelengths with scalpel-based treatment showed positive results, whereas 6 out of 13 (46%) showed no difference, and only 1 out of 13 (7.7%) presented a negative outcome. In addition, 5 out of 6 (83% of ) studies comparing the examined laser wave-lengths with other diodes (808-980 nm) showed positive results, whereas 1 out of 6 (17%) had negative outcomes. Conclusions: A detailed and blinded examination of published studies has been undertaken, applying strict criteria to demonstrate research outcome data, which suggests positive or at worst neutral comparatives when a given laser wavelength system is used against an alternative control therapy. As such, substantiated evidence for laser surgery in delivering uneventful healing and analgesic effects, as an expression of a PBM-like (quasi-PBM) influence, has been shown. [ABSTRACT FROM AUTHOR]

Objective: This systematic review of published research evaluates the parameters and reported outcomes in photobiomodulation therapies (PBMTs) used in management of pain and accelerated tooth movement during orthodontic treatment. Background: Consequent to positive in vitro and animal studies, there has been considerable interest in the potential applications of PBMT to ameliorate pain and to accelerate orthodontic tooth movement. Due to the lack of consistency of wavelengths and parameters applied, there is as yet no consensus in respect of guidance for clinical use. Within the limitations of the reported literature, a digest of key outcomes and parameters is presented here to assist researchers and interested clinicians. Materials and methods: Search engines, PubMed, Google Scholar, and Cochrane, were applied to identify clinical investigations into the potential benefits of PBMTs in orthodontic management. Keywords used were "low-level laser therapy," "low-level light therapy," "photobiomodulation," "orthodontics," "pain," "tooth movement," and "randomized clinical trial ≥5 years." A total of 35 articles were identified, covering the 5-year period January 2013 to December 2018. Only human clinical trials were considered. Seventeen articles were included in this investigation and the reported parameters and outcomes were assessed and presented for comparison. Results: Seven of nine studies supported the effectiveness of PBMT to reduce or prevent pain. There was no consensus on choice of wavelength and a range of parameters were found beneficial. Of the seven tooth movement studies included, four of the seven were positive, of which two used a home-use light-emitting diode (LED) device, as opposed to a clinician-applied laser. A variety of wavelengths and parameters were found to be effective in accelerating tooth movement in the range of 20-40% compared with control. Conclusions: Due to a lack of consistency in approach, further studies are required to achieve a high level of acceptance. The clinical logistics associated with frequent applications supports the concept of patient home delivery use of LED devices, although there are insufficient studies at present to make an evidence-based determination of this type of appliance. To gain more general professional acceptance of the use of PBMT in orthodontics, a continued effort to extend the number of quality human clinical trials is required. Based on the current evidence base, further positive onward progression can be regarded as inevitable. [ABSTRACT FROM AUTHOR]

Objective: This systematic review of published data critically appraises the consistency in the reported delivery parameters used in photobiomodulation (PBM) therapies research within clinical dentistry and makes reporting recommendations for future clinical protocols. Background: Key to the standardization of randomized clinical trials and associated peer-reviewed articles is the disclosure of all laser and light-emitting diode operating parameters. The current status shows a lack of full parameters and significantly impacts on the ability to integrate published data with current and future investigation into clinical PBM therapy. Materials and methods: Search engines, PubMed, Google Scholar, and Cochrane, were scanned for investigation into the effects of PBM therapy research within clinical dentistry. Key words "Low-Level-Laser," "PBM," "Photobiomodulation," "Oral" and "Therapy" were used and a total of 754 articles identified, spanning a period of 9 years and 1 month between February 2009 and March 2018. Only human clinical trials were considered. Fifty-two articles were included in this investigation and the reported basic delivery parameters used in PBM therapies research were considered for each clinical trial. Results: The overall reported basic delivery parameters used in PBM therapies research were too inadequate to be able to be replicated in further studies. These included parameters related to the power meter, beam crosssectional dynamics, fluence, and wider aspects of dosimetry. Conclusions: The delivery parameters used in PBM therapy research within clinical dentistry, investigated in this study, presented a wide variation in their recording or nonrecording of all significant elements needed to have scientific validity. A constant inconsistency in delivering valid, reliable, PBM therapy doses, to target tissues was also identified. The lack of consensus in delivering a sound protocol for PBM therapy, is partly due to the lack of adequate reported materials and methods, which are essential for replication of individual studies. One way to resolve this problem is for Journals to insist on all comprehensive parameter records, used in PBM therapies, to be part of author guidelines in submitting articles of studies on PBM therapy in clinical dentistry. [ABSTRACT FROM AUTHOR]

Dental caries can compromise quality of life and is associated with demineralization of tooth structure by organic acids produced by microorganisms. This study systematically reviewed the dentine caries arrest capabilities of silver diamine fluoride (SDF) and sodium fluoride (NaF). A comprehensive search strategy was developed to identify the relevant publications in electronic databases and hand searched journals and reviews (to March 2018). By applying strict inclusion and exclusion criteria, only six papers (two randomized controlled trials, two follow-up articles and two secondary statistical analysis studies) were considered for full text qualitative and quantitative assessment. The included studies were critically appraised and statistically evaluated. Only four articles were considered for meta-analysis, as the other two were secondary analyses of included studies. When comparing the caries arrest lesions of SDF and NaF, SDF was found to be statistically more effective in dentine caries arrest of primary teeth during the 18 and 30 month clinical examinations. The weighted total effect size of the differences between SDF and NaF regarding arrested caries surfaces was calculated and showed nearly double the effectiveness of SDF to NaF at 30 months. Therefore, SDF is a more effective caries management reagent than NaF. Further clinical research is needed to consolidate the findings of this systematic review. [ABSTRACT FROM AUTHOR]

Abstract Much of our knowledge of early metazoan evolution is derived from unmineralized death mask or endorelief mold and cast fossils in Ediacaran clastic sedimentary rocks. This record is often regarded as a unique 'Ediacaran taphonomic window'; however, the prevalence of soft-bodied molds and casts in Paleozoic clastic rocks has been increasing, begging an extension, or modification, to our understanding of this preservational motif. Chief amongst such fossils are eldonids, a non-biomineralized group of stem deuterostomes. Because eldonids are also preserved as compressed or flattened fossils from deposits like the Burgess Shale, Chengjiang and Kaili, they offer a comparative case study for evaluating the taphonomic fidelity of mold/cast-style preservation during this interval. EDS and Raman microspectroscopic analysis of Ordovician and Devonian eldonid molds and casts, and comparison with Burgess Shale eldonids, suggests the mold/cast taphonomic style produces significantly lower fidelity of fossil preservation. We propose that eldonid mold/cast fossils are preserved by the adsorption of reduced iron ions onto tissues composed primarily of high molecular weight (HMW) biopolymers which require enzymatic degradation prior to decay. Nucleation and growth of aluminosilicates and/or sulfides around these adsorbed ions forms a fossilizable surface veneer, preserving a death mask mold. More labile tissues could not be fossilized in this mold and cast style. Ediacaran mold and cast fossils from South Australia, the White Sea region of Russia, Namibia, and Newfoundland exhibit preservational characteristics consistent with this new proposed model. Analysis of their preservational mode suggests that the first metazoans, which would have lacked HMW biopolymeric tissues, could not have been fossilized in this particular style. Thus, understanding the origin and earliest evolution of the Metazoa requires a focus on alternative modes of fossilization. Highlights • Eldonids from the Tafilalt Lagerstätte are preserved as molds and casts in sandstones. • These preserve only high molecular weight biopolymer tissues, by authigenic mineralization. • Ediacaran molds and casts are fossilized consistent with the Tafilalt taphonomic model. • Tafilalt-style fossils may not preserve entire organisms or complete communities. • The first animals to evolve on Earth could not have been fossilized in this Tafilalt style. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the efficacy of tooth bleaching using ozone after hydrogen peroxide (H2O2) in comparison to the use of H2O2 alone.Methods: 70 extracted teeth were randomly distributed into two groups. Teeth surfaces in group 1 (n=35) were treated using 38% H2O2 and then were exposed to ozone for 60s and this ozonated peroxide mixture was left on the teeth for 20 min. Meanwhile, teeth in group 2 (n=35) were treated with H2O2 38% for 20 min. The L* a* b* and Vita Classic shade values of teeth were evaluated in both groups at base line, after application of H2O2 and ozone in group 1, and after application of H2O2 and then again after another application of ozone in group 2. The statistically significant changes were set at P ≤ 0.05.Results: Baseline L* a* b* and Vita shade values were comparable between groups (P>0.05). Teeth obtained lighter shades following bleaching with both H2O2 and ozone or with H2O2 alone (P ≤ 0.05). Further bleaching with ozone for teeth already bleached with H2O2 alone showed further improvement of the shades of teeth (P<0.001). Teeth treated with H2O2 and ozone had more shade improvements than those only treated with H2O2 (P<0.001). Also, L* values were increased while b* values were decreased (teeth obtained lighter shades) following bleaching in both groups (P ≤ 0.05). More changes were obtained when both ozone and H2O2 were used (P ≤ 0.05).Conclusions: Bleaching with 38% H2O2 and ozone resulted in teeth with lighter shades than bleaching with 38% H2O2 alone. [ABSTRACT FROM AUTHOR]

Background RAS may affect quality of life and impacts oral health and daily activities; consequently, psychological factors, dental needs and patients' perceptions. Professionals should understand this relation to adequately manage oral ulcers. This study aimed at investigating the relationship between oral health impacts, oral health-related quality of life and psychological profiles in patients with recurrent aphthous stomatitis ( RAS). Methods Fifty-three patients (30 men and 23 women, mean age: 31.1 ± 10.1 years) with RAS participated in this study. During ulcer episodes, participants completed Hospital Anxiety and Depression Scale ( HAD), Neuroticism-Extraversion-Openness Five Factor Inventory ( NEO- FFI), Oral Health Impact Profile ( OHIP-14) and United Kingdom Oral Health-Related Quality of Life measure ( OHQoL- UK) proformas. Patients completed OHIP-14 and OHQoL- UK again when they were ulcer-free. The statistically significance levels were set at P ≤ 0.05. Results During ulcer episodes, patients reported worse oral health impacts and an inferior quality of life in comparison with ulcer-free times ( P < 0.0001). Higher OHIP scores were significantly associated with higher HAD depression ( P = 0.036) and anxiety ( P = 0.012) scores. NEO- FFI scores had no significant relations with OHIP and OHQoL- UK scores ( P > 0.05). During ulcer-free periods, no relationships were detected between OHIP, OHQoL- UK, HAD and NEO- FFI scores ( P > 0.05), except between OHQoL- UK and conscientiousness scores ( P = 0.05). Conclusions RAS increased the negative oral health impacts on patients and consequently lowered their quality of life. Stressful situations and conditions (including anxiety and depression), rather than inherent personality profiles and stable psychological traits, were related to oral health impacts and quality of life in patients with RAS. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to clinically quantify the apicoincisal height of the upper interproximal areas directly in patients' mouths compared to measurements on stone models.Subjects and Methods: One hundred and fifty participants (75 females and 75 males, age range 20-45 years) were recruited for this study. A digital caliper was used to measure the anterior maxillary interproximal contact areas directly in patients' mouths and on stone models. The digital caliper accuracy was up to 0.01. The Statistical Package for Social Sciences software (SPSS, version 19.0, Chicago, Ill., USA) was used for statistical analysis. Statistical significance was based on probability values <0.05.Results: The intraoral measurement of proximal contacts as well as the measurement on stone models showed that the dimensions of interproximal contacts on both sides of each tooth were significantly different (p < 0.001) and that the dimension of the mesial contact point was larger than that of the distal contact point of each tooth. The largest contact point was the one between the central incisors (direct intraoral measurement = 2.9-6.49 mm; model measurement = 3.31-6.91 mm). On the other hand, the contact point between the canine and first premolar was the smallest on both sides of the arch (0.63-2.52 mm intraorally, 0.98-2.88 mm on models). The intraoral measurement of contact points was more accurate than model measurements, and the differences were statistically significant (p < 0.001).Conclusions: The clinical evaluation of contact point dimensions using a digital caliper was more precise than measuring contact points on stone models; hence, it is a viable, quick and adequate method to be used routinely. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to clinically quantify the apicoincisal height of the upper interproximal areas directly in patients' mouths compared to measurements on stone models. Subjects and Methods: One hundred and fifty participants (75 females and 75 males, age range 20-45 years) were recruited for this study. A digital caliper was used to measure the anterior maxillary interproximal contact areas directly in patients' mouths and on stone models. The digital caliper accuracy was up to 0.01. The Statistical Package for Social Sciences software (SPSS, version 19.0, Chicago, Ill., USA) was used for statistical analysis. Statistical significance was based on probability values <0.05. Results: The intraoral measurement of proximal contacts as well as the measurement on stone models showed that the dimensions of interproximal contacts on both sides of each tooth were significantly different (p < 0.001) and that the dimension of the mesial contact point was larger than that of the distal contact point of each tooth. The largest contact point was the one between the central incisors (direct intraoral measurement = 2.9-6.49 mm; model measurement = 3.31-6.91 mm). On the other hand, the contact point between the canine and first premolar was the smallest on both sides of the arch (0.63-2.52 mm intraorally, 0.98-2.88 mm on models). The intraoral measurement of contact points was more accurate than model measurements, and the differences were statistically significant (p < 0.001). Conclusions: The clinical evaluation of contact point dimensions using a digital caliper was more precise than measuring contact points on stone models; hence, it is a viable, quick and adequate method to be used routinely. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Objective: To assess the reliability of magnetic resonance imaging (MRI) for detection of esophageal cancer in the Levrat model of end-to-side esophagojejunostomy. Background: The Levrat model has proven utility in terms of its ability to replicate Barrett’s carcinogenesis by inducing gastroduodenoesophageal reflux (GDER). Due to lack of data on the utility of non-invasive methods for detection of esophageal cancer, treatment efficacy studies have been limited, as adenocarcinoma histology has only been validated post-mortem. It would therefore be of great value if the validity and reliability of MRI could be established in this setting. Methods: Chronic GDER reflux was induced in 19 male Sprague-Dawley rats using the modified Levrat model. At 40 weeks post-surgery, all animals underwent endoscopy, MRI scanning, and post-mortem histological analysis of the esophagus and anastomosis. With post-mortem histology serving as the gold standard, assessment of presence of esophageal cancer was made by five esophageal specialists and five radiologists on endoscopy and MRI, respectively. Results: The accuracy of MRI and endoscopic analysis to correctly identify cancer vs. no cancer was 85.3% and 50.5%, respectively. ROC curves demonstrated that MRI rating had an AUC of 0.966 (p<0.001) and endoscopy rating had an AUC of 0.534 (p = 0.804). The sensitivity and specificity of MRI for identifying cancer vs. no-cancer was 89.1% and 80% respectively, as compared to 45.5% and 57.5% for endoscopy. False positive rates of MRI and endoscopy were 20% and 42.5%, respectively. Conclusions: MRI is a more reliable diagnostic method than endoscopy in the Levrat model. The non-invasiveness of the tool and its potential to volumetrically quantify the size and number of tumors likely makes it even more useful in evaluating novel agents and their efficacy in treatment studies of esophageal cancer. [ABSTRACT FROM AUTHOR]

Objectives: To investigate dental impacts on daily living and satisfaction with removable complete and partial prosthodontic rehabilitations, and to identify their relationship with personality profiles. Methods: Sixty-eight patients (38 males and 30 females; mean age = 53.2 ± 11.8 years) received removable prostheses (32 complete dentures and 36 removable partial dentures). Clinical success of prostheses was assessed according specific criteria. The Dental Impact on Daily Living (DIDL) questionnaire was utilized to assess satisfaction with prostheses and impacts on daily living. NEO Five Factor Inventory (NEO-FFI) was utilized to assess patients' personality profiles. Results: Participants' total satisfaction and satisfaction with appearance, pain tolerance, oral comfort, and eating improved after treatment ( p < .05). Position of prosthesis and age had no significant relationships with satisfaction or personality scores ( p > .05). Females were less satisfied with appearance ( p < .05). Patients who received partial dentures were more satisfied with eating and scored higher total satisfaction scores than those who had complete dentures ( p < .05). Before treatment; Neuroticism and Openness scores were associated with dental satisfaction and impacts ( p < .05). After treatment, Conscientious- ness and Extraversion scores were associated with dental satisfaction and impacts ( p < .05). Conclusions: Patients satisfaction with oral condition improved following using removable prosthetic rehabilitation with RPD having better impacts than CD. Psychological profiles (e.g. Neuroticism, Extraversion, Openness and Conscientiousness) might play a role and explain prosthetic impacts on daily living and patients' satisfaction with prostheses. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to quantify tooth wear in upper anterior teeth using a new CADCAM Laser scanning machine, tool maker microscope and conventional tooth wear index. Methods: Fifty participants (25 males and 25 females, mean age = 25 ± 4 years) were assessed for incisal tooth wear of upper anterior teeth using Smith and Knight clinical tooth wear index (TWI) on two occasions, the study baseline and 1 year later. Stone dies for each tooth were prepared and scanned using the CAD-CAM Laser Cercon System. Scanned images were printed and examined under a toolmaker microscope to quantify tooth wear and then the dies were directly assessed under the microscope to measure tooth wear. The Wilcoxon Signed Ranks Test was used to analyze the data. Results: TWI scores for incisal edges were 0-3 and were similar at both occasions. Score 4 was not detected. Wear values measured by directly assessing the dies under the toolmaker microscope (range = 113-150 μm, mean = 130 ± 20 μm) were significantly more than those measured from Cercon Digital Machine images (range = 52-80 μm, mean = 68 ± 23 μm) and both showed significant differences between the two occasions. Conclusions: Wear progression in upper anterior teeth was effectively detected by directly measuring the dies or the images of dies under toolmaker microscope. Measuring the dies of worn dentition directly under tool maker microscope enabled detection of wear progression more accurately than measuring die images obtained with Cercon Digital Machine. Conventional method was the least sensitive for tooth wear quantification and was unable to identify wear progression in most cases. [ABSTRACT FROM AUTHOR]

Objectives: To study the effect of benzocaine mucoadhesive patches (20%) on orthodontic pain caused by elastomeric separators. Subjects and methods. A split-mouth design was used in 30 patients (12 female, 18 male, aged 23 ± 3.75 years). They were instructed to apply benzocaine and placebo patches randomly for right or left first permanent molars of maxillary/mandibular arches for 20 min and repeat this procedure every 6 h with a similar type patch. A 10 cm Visual Analogue Scale (VAS) was used for pain perception assessment in patients who were given benzocaine (benzocaine group) or placebo (placebo group) patches. Pain perception (VAS) was recorded immediately after separator placement and after 2, 6, 12, 18, 24, 48 and 72 h. Results. The mean VAS (SD) for the placebo and benzocaine groups were 2.28 (1.08) and 1.63 (0.67), respectively. The pain peaked at 24 h. Significant pain perception differences were observed between groups at 2, 18, 24, 48 and 72 h. Pain perception was not different between genders or jaws investigated ( p > 0.05). The Friedman test revealed significant differences in pain perception among various time intervals for benzocaine ( χ 2 = 99.84, p = 0.000) and placebo ( χ 2 = 102.361, p = 0.000) groups. Significant negative correlations (ρ) were found only between pain perception scores and patient's ages in the placebo group at 18 (−0.438), 24 (−0.526), 48 (−0.565) and 72 h (−0.458). Conclusion. The recorded mean VAS values were relatively low; however, the benzocaine 20% patches significantly reduced the post-separation orthodontic pain. [ABSTRACT FROM AUTHOR]

[Display omitted] • The ore textures reflect overprint by polyphase deformation and metamorphism. • Main stage of ore modification during D 2 at c. 1.83–1.80 Ga. • Coarse-grained sulphide veins and fracture fillings formed due to remobilisation. • Trace element-mineral chemistry reveals limited redistribution of metals during sulphide remobilisation. • Potential relationship with nearby Cu-Co mineralisation is suggested. This study encompasses the ore mineralogy, textures and sulphide trace element chemistry of the Palaeoproterozoic Lovisa stratiform Zn-Pb deposit and the stratigraphically underlying Lovisa Fe Formation in the Bergslagen ore province (Sweden). We investigate the relative timing of formation and subsequent modifications of its ores in relation to the c. 1.87–1.80 Ga Svecokarelian orogeny. The Lovisa Zn-Pb deposit consists of several different ore types. The massive sphalerite-galena ore is distinctly deformed, exhibiting a multiple-scale "ball ore" texture with rounded silicate clasts within a deformed, fine-grained sulphide matrix. Underlying the massive ore is a locally folded, sphalerite-rich laminated ore, interpreted to represent a metamorphosed relict primary lamination. Several generations of sphalerite-galena fracture fillings and veins occur adjacent to the main ore zones and they cross-cut early ductile structures and metamorphic features. The trace element signatures of the sphalerite-galena infillings generally mimic those of the two main ore zones, thus supporting an origin by localised remobilisation of the primary sulphide ore and demonstrating limited trace element redistribution during this process. In contrast, discrete sulphosalt-rich fracture fillings cross-cutting earlier galena-chalcopyrite-rich fracture fillings and veinlets in the Lovisa Fe Formation suggest a significant but still relatively localised redistribution of metals. Trace element mapping of sulphides from the Lovisa Zn-Pb deposit reveals that inclusion-free overgrowths on pyrite crystals are locally Co-enriched compared to the cores, which resulted from the redistribution of Co during late metamorphic processes. Combined textural and geochemical evidence suggest that the originally syngenetic exhalative sulphide ore at Lovisa was locally strongly affected by polyphase deformation and remobilisation. This was initiated during the first stage of amphibolite facies grade regional metamorphism and deformation (D 1 , c. 1.87–1.85 Ga) but is mostly evident from the later stages (D 2) and the evolution to retrograde and brittle conditions (c. 1.83–1.80 Ga and later). [ABSTRACT FROM AUTHOR]

ABSTRACT Purpose: The objective of this study was to investigate the relationship between satisfaction with implant-supported fixed rehabilitations (ISFPR), their impacts on daily living, and personality profiles. Materials and Methods: Fifty patients (15 men and 35 women; mean age 44.3 ± 9 years), with fitted ISFPR, and 50 partially dentate controls matched with age and gender participated in this study. A Dental Impact on Daily Living questionnaire was used to assess dental satisfaction and impacts of ISFPR on daily living. NEO Five Factor inventory was used to assess participants' personality profiles. Pearson correlation, analysis of variance, and linear regression tests were used for statistical analysis of the data. Results: Patients with ISFPR were more satisfied with their dentition than controls ( p < .05). Patients and controls demonstrated different relationships between personality, impacts on daily living, and satisfaction. Neuroticism, extraversion, and conscientiousness had significant relationships with satisfaction and impacts on daily living in both groups ( p < .05). Openness and agreeableness had significant relationships with satisfaction and impacts on daily living in patients' group ( p < .05). Conclusion: ISFPR had positive impacts on participants' daily living and dental satisfaction. Personality traits (neuroticism, extraversion, openness, agreeableness, and consciousness) impact on daily living and satisfaction with ISFPR, and might predict satisfaction with ISFPR and their impacts on daily living. [ABSTRACT FROM AUTHOR]

Abstract: High-resolution 1H NMR spectroscopy demonstrated that addition of Co(II) ions to isolated human salivary supernatants (HSSs) gave rise to its complexation by a variety of biomolecules. The relative efficacies of these complexants/chelators in this context were classifiable by the influence of added Co(II) on their line-widths and chemical shift values, and also the added Co(II) concentration-dependence of these spectral modifications. Those which were most affected by the addition of this metal ion were lactate > formate ≈histidinate > succinate, this order reflecting the ability of these complexants to compete for the available Co(II) in terms of (1) thermodynamic equilibrium constants for the formation of their complexes and (2) their HSS concentrations. Since many of these HSS Co(II) complexants (particularly lactate, formate and histidine) serve as powerful OH scavengers, the results acquired indicate that any of this radical generated from the Co(II) source in such complexes via pseudo-Fenton reactions may be ‘site-specifically’ scavenged. The significance of these observations regarding the in vivo corrosion of cobalt-containing metal alloy dental prostheses (e.g., Co–Cr alloys), the availability of trace levels of this metal ion in human saliva, and cobalt toxicity, is discussed. [Copyright &y& Elsevier]

Abstract: Objectives: This study aimed to evaluate the reliability of a new CAD-CAM Laser scanning machine in detection of incisal tooth wear through a 6-month period and to compare the accuracy of using this new machine against measuring tooth wear using tool maker microscope and conventional tooth wear index. Methods: Twenty participants (11 males and 9 females, mean age=22.7 years, SD=2.0) were assessed for incisal tooth wear of lower anterior teeth using Smith and Knight clinical tooth wear index (TWI) on two occasions, the study baseline and 6 months later. Stone dies for each tooth were prepared and scanned using the CAD-CAM Laser Cercon System (Cercon Smart Ceramics, DeguDent, Germany). Scanned images were printed and examined under a toolmaker microscope (Stedall-Dowding Machine Tool Company, Optique et Mecanique de Precision, Marcel Aubert SA, Switzerland) to quantify tooth wear and then the dies were directly assessed under the microscope to measure tooth wear. The Wilcoxon Signed Ranks Test was used to analyse the data. Results: TWI scores for incisal edges were 0, 1, and 2 and were similar at both occasions. Scores 3 and 4 were not detected. Wear values measured by directly assessing the dies under the tool maker microscope (range=517–656μm, mean=582μm, and SD=50) were significantly more than those measured from the Cercon digital machine images (range=132–193μm, mean =165μm, and SD=27) and both showed significant differences between the two occasions. Conclusions: Measuring images obtained with Cercon digital machine under tool maker microscope allowed detection of wear progression over the 6-month period. However, measuring the dies of worn dentition directly under the tool maker microscope enabled detection of wear progression more accurately. Conventional method was the least sensitive for tooth wear quantification and was unable to identify wear progression in most cases. [Copyright &y& Elsevier]