A Clinically Explainable AI-Based Grading System for Age-Related Macular Degeneration Using Optical Coherence Tomography.

We propose an automated, explainable artificial intelligence (xAI) system for age-related macular degeneration (AMD) diagnosis. Mimicking the physician's perceptions, the proposed xAI system is capable of deriving clinically meaningful features from optical coherence tomography (OCT) B-scan images to differentiate between a normal retina, different grades of AMD (early, intermediate, geographic atrophy (GA), inactive wet or active neovascular disease [exudative or wet AMD]), and non-AMD diseases. Particularly, we extract retinal OCT-based clinical imaging markers that are correlated with the progression of AMD, which include: (i) subretinal tissue, sub-retinal pigment epithelial tissue, intraretinal fluid, subretinal fluid, and choroidal hypertransmission detection using a DeepLabV3+ network; (ii) detection of merged retina layers using a novel convolutional neural network model; (iii) drusen detection based on 2D curvature analysis; (iv) estimation of retinal layers' thickness, and first-order and higher-order reflectivity features. Those clinical features are used to grade a retinal OCT in a hierarchical decision tree process. The first step looks for severe disruption of retinal layers' indicative of advanced AMD. These cases are analyzed further to diagnose GA, inactive wet AMD, active wet AMD, and non-AMD diseases. Less severe cases are analyzed using a different pipeline to identify OCT with AMD-specific pathology, which is graded as intermediate-stage or early-stage AMD. The remainder is classified as either being a normal retina or having other non-AMD pathology. The proposed system in the multi-way classification task, evaluated on 1285 OCT images, achieved 90.82% accuracy. These promising results demonstrated the capability to automatically distinguish between normal eyes and all AMD grades in addition to non-AMD diseases.

Success of fixed partial denture prostheses observed in a military dental centre: A cross-sectional study.

Background: Fixed dental prostheses have been provided in the Armed Forces for a long time, yet definite evidence-based guidelines on the success and failure of different types of prostheses are currently lacking. A cross-sectional observational study was conducted as a step towards addressing this lacuna. Methods: The study included 156 patients and 538 prostheses based on pre-established inclusion criteria. The types of prostheses that were evaluated included crowns, fixed partial dentures (FPDs), post and core restorations, dental implants and veneers. Visual, tactile and radiographic examination was used for evaluating the prostheses. Success, survival and failure of prostheses were evaluated, and the types of complications leading to the failure were also recorded. In addition, the oral hygiene status of the included patients was also evaluated using the Oral Hygiene Index-Simplified. Results: The overall failure rate in all prostheses combined together was 28.81%. The failure rate in cantilever FPDs was the highest at 44.44%. It was 16.67% in veneers, 35.37% in conventional FPDs, 23.81% in single crowns and 30.56% in all post and core restorations. Conclusion: Barring the all-ceramic prostheses and fibre post and core restorations, the rate of occurrence of both complications and failures in the remaining categories of prostheses was higher than that mentioned in the literature.

Challenges and visions for managing pain-related insomnia in primary care using the hybrid CBT approach: a small-scale qualitative interview study with GPs, nurses, and practice managers.

BACKGROUND: Chronic pain and insomnia have a complex, bidirectional relationship - addressing sleep complaints alongside pain may be key to alleviating patient-reported distress and disability. Healthcare professionals have consistently reported wanting to offer psychologically informed chronic pain management at the primary care level. Research in secondary care has demonstrated good treatment efficacy of hybrid CBT for chronic pain and insomnia. However, primary care is typically the main point of treatment entry, hence may be better situated to offer treatments using a multidisciplinary approach. In this study, primary care service providers' perception of feasibility for tackling pain-related insomnia in primary care was explored. METHODS: The data corpus originates from a feasibility trial exploring hybrid CBT for chronic pain and insomnia delivered in primary care. This formed three in-depth group interviews with primary care staff (n = 9) from different primary care centres from the same NHS locale. All interviews were conducted on-site using a semi-structured approach. Verbal data was recorded, transcribed verbatim and analysed using the thematic analysis process. RESULTS: Eight themes were identified - 1) Discrepant conceptualisations of the chronic pain-insomnia relationship and clinical application, 2) Mismatch between patients' needs and available treatment offerings, 3) Awareness of psychological complexities, 4) Identified treatment gap for pain-related insomnia, 5) Lack of funding and existing infrastructure for new service development, 6) General shortage of psychological services for complex health conditions, 7) Multidisciplinary team provision with pain specialist input, and 8) Accessibility through primary care. These mapped onto four domains - Current understanding and practice, Perceived facilitators, Perceived barriers, Ideal scenarios for a new treatment service - which reflected the focus of our investigation. Taken together these provide key context for understanding challenges faced by health care professionals in considering and developing a new clinical service. CONCLUSIONS: Primary care service providers from one locale advocate better, multidisciplinary treatment provision for chronic pain and insomnia. Findings suggest that situating this in primary care could be a feasible option, but this requires systemic support and specialist input as well as definitive trials for success.

Oral pain and infection control strategies for treating children and adolescents in India.

INTRODUCTION: Oral and dental health form an integral part of complete well being of an individual and society at large. Promoting oral health and societal progression go hand in hand. AIM: To investigate dentists' attitudes about pain and infection control while treating children and adolescents by assessing their recommendations of pre- and postoperative analgesics and antibiotics, and use of local anesthesia (LA) for definitive treatment in different clinical scenarios. MATERIALS AND METHOD: A total of 400 dentists, both general dental practitioners (GDPS) as well as specialist dentists, were surveyed over a period of 2 months by using a pre-tested close-ended questionnaire. The data was statistically analyzed using Pearson's Chi-square test and backward logistic regression analysis for analysis of categorical variables and independent variables, respectively. Level of significance was set at 5%. RESULTS: It was found that there was a gross overuse of antibiotics and analgesics and under use of LA by GDPs compared to specialist dentists. Postoperative antibiotics and analgesics were used more commonly than preoperative antibiotics and analgesics. These strategies were used more often in permanent teeth than primary teeth except the use of LA, which was used with equal frequency in both primary as well as permanent dentition. CONCLUSION: Dependence on antibiotics and analgesics for achieving pain and infection control in children has to be minimized and focus has to be shifted on judicious definitive treatment involving use of LA, aseptic techniques, and behavior management techniques.

Precise higher-order reflectivity and morphology models for early diagnosis of diabetic retinopathy using OCT images.

This study proposes a novel computer assisted diagnostic (CAD) system for early diagnosis of diabetic retinopathy (DR) using optical coherence tomography (OCT) B-scans. The CAD system is based on fusing novel OCT markers that describe both the morphology/anatomy and the reflectivity of retinal layers to improve DR diagnosis. This system separates retinal layers automatically using a segmentation approach based on an adaptive appearance and their prior shape information. High-order morphological and novel reflectivity markers are extracted from individual segmented layers. Namely, the morphological markers are layer thickness and tortuosity while the reflectivity markers are the 1st-order reflectivity of the layer in addition to local and global high-order reflectivity based on Markov-Gibbs random field (MGRF) and gray-level co-occurrence matrix (GLCM), respectively. The extracted image-derived markers are represented using cumulative distribution function (CDF) descriptors. The constructed CDFs are then described using their statistical measures, i.e., the 10th through 90th percentiles with a 10% increment. For individual layer classification, each extracted descriptor of a given layer is fed to a support vector machine (SVM) classifier with a linear kernel. The results of the four classifiers are then fused using a backpropagation neural network (BNN) to diagnose each retinal layer. For global subject diagnosis, classification outputs (probabilities) of the twelve layers are fused using another BNN to make the final diagnosis of the B-scan. This system is validated and tested on 130 patients, with two scans for both eyes (i.e. 260 OCT images), with a balanced number of normal and DR subjects using different validation metrics: 2-folds, 4-folds, 10-folds, and leave-one-subject-out (LOSO) cross-validation approaches. The performance of the proposed system was evaluated using sensitivity, specificity, F1-score, and accuracy metrics. The system's performance after the fusion of these different markers showed better performance compared with individual markers and other machine learning fusion methods. Namely, it achieved [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], respectively, using the LOSO cross-validation technique. The reported results, based on the integration of morphology and reflectivity markers and by using state-of-the-art machine learning classifications, demonstrate the ability of the proposed system to diagnose the DR early.

Stubble burn area estimation and its impact on ambient air quality of Patiala & Ludhiana district, Punjab, India.

Stubble burning during October and November, results in the extensive formation of smoke cloud over the Punjab region, and maybe one of the main reasons behind the increase in air pollution levels in these areas. The manual detection and estimation are tedious, lengthy and unpractical, so several researchers have been using remote sensing and GIS technique to estimate stubble burn areas and forest fires. Thus, in the present study, an attempt has been made to detect and estimate the stubble burn area. Landsat 8 OLI images are used to detect the stubble burn area for the year 2014-18 for Patiala and Ludhiana, which are major rice producing districts of Punjab. Normalize Burn Ratio (NBR) index have been used to determine the burned area in an image using a statistical threshold technique (2σ approach). The results have been validated using available as well as collected Ground Control Points (GCPs) and accuracy assessment has been conducted by generating an error matrix. It has been estimated that the stubble burn area was reduced by 32% and 40% during the study period for Patiala and Ludhiana regions, respectively. The monthly variation for various pollutants (RSPM, NOx, and SO2) during the study period has also been studied and analyzed. The distinct increase in pollutant levels has been observed during each stubble burning period. The results also indicate that the amount of emitted RSPM and NOx was higher than the emitted SO2 during stubble burning. The wind rose diagrams have also been plotted.

Effect of Sugarcane Cultivar and Foliar Insecticide Treatment on Infestations of the Invasive Sugarcane Thrips, Fulmekiola serrata (Thysanoptera: Thripidae), in Florida.

Fulmekiola serrata (Kobus) was observed infesting sugarcane, Saccharum spp. hybrids, in the United States for the first time in January 2017 in Florida. Field studies were conducted to determine F. serrata infestation levels on popular sugarcane cultivars and to determine the efficacy of foliar insecticide treatments that could be used for management. Cultivar evaluations comparing six and five commercial cultivars representing >46% of the sugarcane production area in Florida were conducted in 2017 and 2018, respectively. Fulmekiola serrata infestation levels did not differ among cultivars in 2017. However, infestation levels on CP 00-1101 were greater than on CP 96-1252 grown on organic soils, and infestation levels on CP 96-1252 were greater than on CPCL 97-2730 grown on mineral soils in 2018. Three insecticide evaluations, two in 2017 and one in 2018, were conducted. The pyrethroid lambda-cyhalothrin, which is registered for use on sugarcane, was consistently associated with the greatest decreases in F. serrata infestation levels. The neonicotinoids imidacloprid and thiamethoxam, as well as the butenolide flupyradifurone, decreased infestation levels but to a lesser extent than did lambda-cyhalothrin. The spinosyn spinetoram was associated with the lowest decreases in F. serrata infestation levels. Our results supported short-term F. serrata management recommendations: Popular Florida sugarcane cultivars should be considered equally susceptible to F. serrata until additional evaluations are conducted and F. serrata outbreaks can be treated with lambda-cyhalothrin when infestations stress the crop beyond acceptable levels.

Acupuncture in hospice settings: A qualitative exploration of patients' experiences.

Whilst acupuncture has the potential to impact on many aspects of health and well-being, including end-of-life care, there is little research regarding patients' experiences of its effects within the context of palliative care in hospice settings. The aim of this study was to address this gap, by exploring patients' experiences of acupuncture within this setting. In-depth, semi-structured interviews were conducted with a sample of eighteen patients who had received acupuncture as part of hospice care. Transcription of data, with thematic analysis, identified two overarching themes: (1) participant perceptions of the effects of acupuncture including pain control, improved physical and emotional health, spiritual well-being and awareness of health as a holistic phenomenon; and (2) factors which participants believed enabled acupuncture to have these effects including the quality of the practitioner relationship, engagement of participants in the process of their treatment and prior expectations that acupuncture could work. Acupuncture was found to be a highly acceptable, accessible and popular treatment with positive holistic effects reported across the domains of physical, mental and spiritual health and no serious adverse effects. By enabling awareness of the holistic nature of health and well-being, acupuncture was experienced as having the potential to contribute to a better death, an emergent theory that needs testing in further studies. In the meanwhile, the results of this study offer encouragement to hospices currently providing or considering investing in acupuncture provision.

Combined cognitive-behavioural and mindfulness programme for people living with dystonia: a proof-of-concept study.

OBJECTIVES: To design and test the delivery of an intervention targeting the non-motor symptoms of dystonia and pilot key health and well-being questionnaires in this population. DESIGN: A proof-of-concept study to test the delivery, acceptability, relevance, structure and content for a 3-day group residential programme for the management of dystonia. SETTING: Participants were recruited from a single botulinum toxin clinic. The intervention was delivered in the community. PARTICIPANTS: 14 participants consented to take part (2 withdrew prior to the starting of intervention). The average age was 60 years (range 44-77), 8 of whom were female. After drop-out, 9 participants completed the 3-day programme. INTERVENTION: A 3-day group residential programme. PRIMARY AND SECONDARY OUTCOME MEASURES: Process evaluation and interviews were carried out before and after the intervention to explore participant's views and expectations, as well as experiences of the intervention. Select questionnaires were completed at baseline, 1-month and 3-month follow-up. RESULTS: Although participants were not sure what to expect from the programme, they found it informative and for many this together with being in a group with other people with dystonia legitimised their condition. Mindfulness was accepted and adopted as a coping strategy. This was reflected in the 1-month follow-up. CONCLUSIONS: We successfully delivered a 3-day residential programme to help those living with dystonia manage their condition. Further improvements are suggested. The quantitative outcome measures were acceptable to this group of patients with dystonia.

Comparative evaluation of the tensile bond strength of two silicone based denture liners with denture base resins.

BACKGROUND: To evaluate and compare tensile bond strength of two silicone based liners with heat cure and heat cure high impact denture base resin at baseline and after storage in artificial saliva for 30 and 60 days. METHOD: Heat cure conventional and high impact acrylic blocks (120 blocks each) prepared with final test specimen of two blocks of each resin with a liner. The baseline samples and those tested after 30 and 60 days interval stored in artificial saliva in thermal incubator, all were pulled apart in UTM at 20 mm/min. The tensile bond strength and mode of failure (adhesive/cohesive) were assessed. Mean, SD determined and analysis using one way ANOVA and paired 't' test. RESULTS: The highest mean tensile bond strength (1.028 MPa) and the least i.e. 0.289 MPa was observed with Permaflex silicone liner against heat cure PMMA after storage in artificial saliva at 37 ± 1 °C. CONCLUSION: The study rejected the null hypothesis because storage time in artificial saliva affected the bond strength of the resilient liners examined. The results revealed a statistically significant difference (p < 0.05) of artificial saliva storage on the bond strength of both the liners. After storage in artificial saliva for 30 days and 60 days at 37 ± 1 °C, all the specimens showed a significant reduction in the tensile bond strength.

Behavioural interventions for people living with adult-onset primary dystonia: a systematic review.

BACKGROUND: Primary dystonia is a chronic neurological movement disorder that causes abnormal muscle movements. Pain and emotional distress may accompany these physical symptoms. Behavioural interventions are used to help people with long term conditions improve their quality of life. Little is known about behavioural interventions applied to Dystonia. We report a systematic review of studies reporting current evidence of behavioural interventions for people with primary dystonia. METHODS: We did systematic searches of Medline, PsycINFO, AHMED and CINAHL. We assessed the methodological quality of included studies using a risk of bias tool. Any disagreements were resolved by liaising with an independent rater. Physiological outcomes such as dystonia severity and psychological outcomes such as sleep and depression were selected on the basis that primary dystonia causes motor and non-motor symptoms. No time limit was placed on the searches. A narrative synthesis of the results is presented. RESULTS: Of 1798 titles and abstracts screened, 14 full articles were retrieved and inclusion and exclusion criteria applied. Of these a final nine were eligible for the review (N = 73). Only two were Randomised Controlled Trials (RCTs). Using the Movement Disorders Society (MDS) dystonia classification, that was published after this work started, all of the included studies were of idiopathic adult onset focal dystonia without associated features. These included: blepharospasm (eye dystonia) (N = 1), cervical dystonia (neck dystonia) (N = 2), writer's cramp (hand dystonia) (N = 3) and the yips (N = 3). No studies reported on dystonia that affects two or more body regions. Studies reported good adherence and response rates to treatment. Physiological and psychological improvements were noted in all studies at weekly, monthly and yearly follow-ups. Caution should be taken when interpreting the results because of the scarcity of RCTs identified, use of small sample sizes, and inappropriate statistical methods. CONCLUSION: We identified few studies; mainly of poor methodological quality that all studied a focal dystonia. It is not possible to draw firm conclusions. Nevertheless, the data suggests that a combined behavioural therapy approach including relaxation practice for people with idiopathic adult onset focal dystonia merits further investigation.

Reducing routine vaccination dropout rates: evaluating two interventions in three Kenyan districts, 2014.

BACKGROUND: Globally, vaccine preventable diseases are responsible for nearly 20% of deaths annually among children <5 years old. Worldwide, many children dropout from the vaccination program, are vaccinated late, or incompletely vaccinated. We evaluated the impact of text messaging and sticker reminders to reduce dropouts from the vaccination program. METHODS: The evaluation was conducted in three selected districts in Kenya: Machakos, Langata and Njoro. Three health facilities were selected in each district, and randomly allocated to send text messages or provide stickers reminding parents to bring their children for second and third dose of pentavalent vaccine, or to the control group (routine reminder) with next appointment date indicated on the well-child booklet. Children aged <12 months presenting for their first dose of pentavalent vaccine were enrolled. A dropout was defined as not returning for vaccination ≥ 2 weeks after scheduled date for third dose of pentavalent vaccine. We calculated dropout rate as a percentage of the difference between first and third pentavalent dose. RESULTS: We enrolled 1,116 children; 372 in each intervention and 372 controls between February and October 2014. Median age was 45 days old (range: 31-99 days), and 574 (51%) were male. There were 136 (12%) dropouts. Thirteen (4%) children dropped out among those who received text messages, 60 (16%) among who received sticker reminders, and 63 (17%) among the controls. Having a caregiver with below secondary education [Odds Ratio (OR) 1.8, 95% Confidence Interval (CI) 1.1-3.2], and residing >5 km from health facility (OR 1.6, CI 1.0-2.7) were associated with higher odds of dropping out. Those who received text messages were less likely to drop out compared to controls (OR 0.2, CI 0.04-0.8). There was no statistical difference between those who received stickers and controls (OR 0.9, CI 0.5-1.6). CONCLUSION: Text message reminders can reduce vaccination dropout rates in Kenya. We recommend the extended implementation of text message reminders in routine vaccination services.

Exploring culturally competent primary care diabetes services: a single-city survey.

AIMS: To determine the cultural competence of diabetes services delivered to minority ethnic groups in a multicultural UK city with a diabetes prevalence of 4.3%. METHODS: A semi-structured survey comprising 35 questions was carried out across all 66 general practices in Coventry between November 2011 and January 2012. Data were analysed using descriptive statistics. The cultural competence of diabetes services reported in the survey was assessed using a culturally competent assessment tool (CCAT). RESULTS: Thirty-four general practices (52%) responded and six important findings emerged across those practices. (1) Ninety-four per cent of general practices reported the ethnicity of their populations. (2) One in three people with diabetes was from a minority ethnic group. (3) Nine (26.5%) practices reported a diabetes prevalence of between 55% and 96% in minority ethnic groups. (4) The cultural competences of diabetes services were assessed using CCAT; 56% of practices were found to be highly culturally competent and 26% were found to be moderately culturally competent. (5) Ten practices (29%) reported higher proportionate attendance at diabetes annual checks in the majority white British population compared with minority ethnic groups. (6) Cultural diversity in relation to language and strong cultural traditions around food were most commonly reported as barriers to culturally competent service delivery. CONCLUSIONS: Seven of the eight cultural barriers identified in the global evidence were present in the city. Use of the CCAT to assess existing service provision and the good baseline recording of ethnicity provide a sound basis for commissioning culturally competent interventions in the future.

Two Pelvic Digits on Same Side: Double Trouble?

Pelvic digit is a rare congenital anomaly of pelvis usually discovered incidentally on plain radiography. It usually develops in the soft tissue adjacent to the normal skeletal tissue. Its importance lays in its differentiation from heterotopic ossification, osteochondroma, Fong's disease and traumatic avulsion injuries of pelvis to avoid any unnecessary investigations and interventions. Here, we report a 32-year-old male presenting with complain of pain in right hip, was subjected to radiographic examination and two pelvic digits were noticed arising from the iliac bone in addition to features of osteoarthritis of hip joint. The symptomatology was attributed to osteoarthritis of hip after thorough physical examination and imaging investigations.

Environmental microdosimetry: microdosimetric characterisation of low-dose exposures.

A number of researchers, as well as the International Commission on Radiation Units and Measurements, have described how concepts and quantities used in microdosimetry best capture the stochastic nature of low-level exposures in terms of cell hits and the fraction of cells affected within a tissue. However, the concepts of microdosimetry are not generally intuitive to the public or indeed to health physicists. In this article, the methods of conventional internal dosimetry was applied to different forms of radioactive iodine to derive cell-hit numbers and cell fractions affected by low-level exposures, and it is shown that microdosimetric analysis is compatible with conventional dosimetry but has the advantage of underscoring the stochastic nature of ionising radiation at low dose. The microdosimetric description of low-dose exposures derived in this work could be improved with the use of Monte Carlo track structure codes and more realistic models of different tissues and their cellular structure.

Interspecific competition between two generalist parasitoids that attack the leafroller Epiphyas postvittana (Lepidoptera: Tortricidae).

Two generalist parasitoids, Dolichogenidea tasmanica (Cameron) (Hymenoptera: Braconidae) and Therophilus unimaculatus (Turner) (Hymenoptera: Braconidae) attack early instars of tortricid moths, including the light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae). The two parasitoids co-exist in natural habitats, while D. tasmanica is dominant in vineyards, whereas T. unimaculatus occurs mainly in adjacent native vegetation. This difference suggests possible competition between the two species, mediated by habitat. Here, we report on the extent of interspecific differences in host discrimination and the outcome of interspecific competition between the two parasitoids. The parasitoids did not show different behavioural responses to un-parasitized hosts or those that were parasitized by the other species. Larvae of D. tasmanica out-competed those of T. unimaculatus, irrespective of the order or interval between attacks by the two species. The host larvae that were attacked by two parasitoids died more frequently before a parasitoid completed its larval development than those that were attacked by a single parasitoid. Dissection of host larvae parasitized by both species indicated that first instars of D. tasmanica attacked and killed larval T. unimaculatus.

Determination of mesiodistal width of maxillary anterior teeth using inner canthal distance.

BACKGROUND: Selection of appropriately sized maxillary anterior teeth is one of the important aspects of complete denture prosthodontics. In the past several methods have been proposed, but little consensus on an effective method for anterior teeth selection has been reached. Inner canthal distance is one of the reliable anatomic dimension that may provide a valid approach to anterior teeth selection. This study was aimed to ascertain the co-relation between inner canthal distance (ICD) and combined mesiodistal width of maxillary anterior teeth. METHOD: This study was conducted in Army Dental Centre (R & R) Delhi Cantonment between Aug 2006 to Mar 2008. Eight hundred dentate Indian subjects of four different ethnic group; Such as Rajputs, Marathas, Sikh and Tamilian. 100 males and 100 females from each race under the age group of 18-30 years formed the subjects of study. The ICD and mesio-distal width of maxillary anteriors were measured using Digital Vernier Caliper. The Data obtained was statistically analyzed. RESULTS: A consistent ratio of 1.61 was found between ICD and combined mesiodistal width of maxillary anteriors in all four ethnic group. The mean value showed no statistically significant difference between sex. The variation in the ratio between the ethnic groups was negligible. CONCLUSION: The findings of the study indicated that, to select the combined mesiodistal width of maxillary anterior teeth, ICD of the required patient should be multiplied by 1.61. This ratio was consistent with all the four ethnic groups irrespective of sex.

Haematological alterations induced by oral subacute exposure to fenvalerate, nitrate and their combination in domestic buffalo, Bubalus bubalis.

The present study investigated haematological alterations induced by oral subacute exposure to fenvalerate, nitrate and their combination in the domestic buffalo, Bubalus bubalis. Fenvalerate exposure produced significant declines in haemoglobin (Hb), total leukocyte count (TLC), total erythrocyte count (TEC) and mean corpuscular haemoglobin concentration (MCHC), and a corresponding elevation in mean corpuscular volume (MCV). Following oral exposure to sodium nitrate, significant declines in blood Hb, TLC, TEC, MCH and MCHC, and a significant elevation in MCV occurred. Combined exposure to fenvalerate and sodium nitrate produced severe effects with an appreciably more prominent decline in Hb, TLC, TEC and MCHC and a significant elevation in MCV. The percentage of methaemoglobin was observed to follow an elevating trend in animals exposed to sodium nitrate alone (0.69 %-13.8 %) and in combination with fenvalerate (0.75 %-13.7 %).

Evaluation of shear bond strength of composite resin bonded to alloy treated with sandblasting and electrolytic etching.

Conservation of natural tooth structure precipitated the emergence of resin-retained fixed partial dentures. The weakest link in this modality is the bond between resin cement and alloy of the retainer. Various alloy surface treatment have been recommended to improve alloy-resin bond. This in vitro study was carried out to observe changes in the Nickel-Chromium alloy (Wiron 99, Bego) surface following sandblasting or electrolytic etching treatment by scanning electron microscope (SEM) and to evaluate the shear bond strength of a resin luting cement bonded to the surface treated alloy. 80 alloy blocks were cast and divided into four groups of 20 each. In groups-A & B, the test surfaces were treated by sandblasting with 50 and 250 µm sized aluminium oxide particles respectively. In groups-C & D, the test surfaces were first treated by sandblasting with 50 and 250 µm sized aluminium oxide particles respectively followed by electrolytic etching. Test surfaces were observed under SEM at 1,000× magnification. Two alloy blocks of each group were luted together by a resin luting cement (Rely X, 3M) and their shear bond strength was tested. The mean shear bond strength in MPa of groups-A to D were 6.44 (±0.74), 8.18 (±0.51), 14.45 (±0.59) and 17.43 (±1.20) respectively. Group-D showed bond strength that is more than clinically acceptable bond strength. It is recommended that before luting resin-retained fixed partial dentures, the fitting surface of the retainer should be electrolytically etched to achieve adequate micromechanical retention.