Evaluation of the marginal microleakage of CAD-CAM compared with conventional interim crowns luted with different types of cement: An in-vitro study.

BACKGROUND: Temporary stage in crowns and bridgework plays an important role in the success and failure of the final restorations. Lack of marginal seal of the temporary restorations can lead to further complications. Recently, digital dentistry has been improved in terms of marginal integrity. AIMS: The aim of this study was to evaluate and compare the marginal leakage between CAD/CAM and conventionally made Polymethyl methacrylate (PMMA) interim crowns cemented with different temporary luting cements. MATERIALS AND METHODS: Sixty resin dies of a maxillary right first premolar were prepared according to the protocol of the tooth preparation for all-ceramic crown. Interim crowns were then fabricated and assigned to two main groups according to the fabrication technique (CAD/CAM technique and conventional technique). Furthermore, the samples were sub-grouped (n = 10) according to the type of the luting cements: Zinc oxide eugenol (RelyX temp E), Zinc oxide non-eugenol (RelyX temp NE), and Zinc polycarboxylate cement (pentron). The specimens were then subjected to thermocycling at 5°C and 55°CC for 30 sec and transfer time of 15 seconds for 1500 cycles. After that, the specimens were immersed in a 2% methylene blue solution for 24 hours. The cemented specimens were sectioned buccolingually and the amount of marginal leakage was evaluated under digital microscope at magnification 50x. The scores of dye penetration were recorded and analyzed using one-way ANOVA at P < 0.05 for all tests. RESULTS: For the fabrication technique, CAD/CAM-made interim crowns had significantly better performance in terms of lower microleakage in comparison to conventionally built interim crowns (P < 0.001). Overall, Zinc Oxide non-eugenol also showed significantly least microleakage as a luting cement then Zinc Oxide Eugenol and the most microleakage was found with Zinc Polycarboxylate regardless of the fabrication method. CONCLUSION: Interim crowns fabricated by CAD-CAM system are better suited for temporization. Zinc-oxide non-eugenol cements showed the least amount of microleakage in both types of crown.

Evaluation of the causes of failure of root canal treatment among patients in the City of Al-Kharj, Saudi Arabia.

BACKGROUND: Endodontic treatment failure is one of the most common problems encountered in dentistry. AIMS: This study aimed to evaluate the causes of failure of endodontic treatment among patients in the Saudi Arabian city of Al-Kharj. SUBJECTS AND METHODS: A total of 250 patients of both genders were involved in the study. Criteria confirming the failure of the endodontic treatment were pain, tenderness on pressure, periapical radiolucency, and sinus tract. Patients were selected by convenience sampling methods. A diagnostic chart was prepared to complete the investigation in three different hospitals, during a six-month period (October 2018 - March 2019). The results were analyzed statistically using Chi-square test and use of simple arithmetical methods to determine percentage and frequencies. RESULTS: The main cause for endodontic failure was poor quality adjunctive treatment. 147 out of 179 male patients and 53 out of 71 female patients received poor quality treatment. There was a statistically significant difference between gender versus adjunctive treatment (P = 0.009) and between hospital versus adjunctive treatment (P = 0.005), and quality of adjunctive treatment between private hospital as compared to government hospital which was also statistically significant (P = 0.008). In quadrant wise distribution, first molars were the most commonly involved teeth. Inadequate filling of the root canal was (36.8%), missed canals (14.4), over-extension root canal fillings (12.8%), perforations (9.6%), instrumentation related (8.8%), and endodontic access preparation related (2.4%) in the decreasing order of frequency were seen as the most common causes of failure of endodontic treatment. CONCLUSION: First molars were the most commonly affected tooth in the failure of endodontic treatment. Poor adjunctive treatment and inadequate filling of the root canals were the most common causes of endodontic failure, more commonly seen in male than female patients and in private clinics/hospitals than government hospitals.

The sample of choice for detecting Middle East respiratory syndrome coronavirus in asymptomatic dromedary camels using real-time reversetranscription polymerase chain reaction.

The newly identified Middle East respiratory syndrome coronavirus (MERS-CoV), which causes severe respiratory disease, particularly in people with comorbidities, requires further investigation. Studies in Qatar and elsewhere have provided evidence that dromedary camels are a reservoir for the virus, but the exact modes of transmission of MERS-CoV to humans remain unclear. In February 2014, an assessment was made of the suitability and sensitivity of different types of sample for the detection of MERSCoV by real-time reverse-transcription polymerase chain reaction (RT-PCR) for three gene targets: UpE (upstream of the E gene), the N (nucleocapsid) gene and open reading frame (ORF) 1a. Fifty-three animals presented for slaughter were sampled. A high percentage of the sampled camels (79% [95% confidence interval 66.9-91.5%, standard error 0.0625]; 42 out of 53) were shown to be shedding MERS-CoV at the time of slaughter, yet all the animals were apparently healthy. Among the virus-positive animals, nasal swabs were most often positive (97.6%). Oral swabs were the second most frequently positive (35.7%), followed by rectal swabs (28.5%). In addition, the highest viral load, expressed as a cycle threshold (Ct) value of 11.27, was obtained from a nasal swab. These findings lead to the conclusion that nasal swabs are the candidate sample of choice for detecting MERS-CoV using RT-PCR technology in apparently healthy camels.

Des travaux de recherche approfondis sont encore nécessaires concernant le coronavirus responsable du syndrome respiratoire du Moyen-Orient (MERSCoV), un virus identifié récemment et qui provoque des troubles respiratoires sévères en particulier chez les individus atteints de pathologies multiples. Les études effectuées au Qatar et ailleurs ont démontré que les dromadaires font office de réservoirs du virus ; toutefois, les modalités précises de la transmission du MERS-CoV à l'être humain demeurent obscures. En février 2014, une équipe de chercheurs a évalué l'adéquation et la sensibilité de plusieurs types d'échantillons pour détecter le MERS-CoV en utilisant l'amplification en chaîne par polymérase couplée à une transcription inverse en temps réel (RT-PCR) spécifique pour trois cibles génétiques, à savoir la séquence UpE (en amont du gène E), le gène N (nucléocapside) et le cadre de lecture ORF1a. Pour ce faire, divers prélèvements ont été effectués sur 53 dromadaires destinés à l'abattage. Un fort pourcentage de ces dromadaires (79 % [intervalle de confiance à 95 % compris entre 66,9 et 91,5 %, erreur standard : 0,0625], soit 42 sur 53) excrétaient le MERSCoV au moment de l'abattage, mais aucun ne présentait le moindre signe clinique. Les échantillons dans lesquels le plus de cas positifs ont été détectés étaient les écouvillons nasaux (97,6 %). Venaient ensuite les écouvillons oraux, qui ont détecté 35,7 % de cas positifs, puis les écouvillons rectaux (28,5 % de cas positifs détectés). Par ailleurs, ce sont les écouvillons nasaux qui ont permis d'obtenir l'intensité la plus élevée de la réponse de la RT-PCR, exprimée en une valeur du seuil de cycles de 11,27. Ces résultats permettent de conclure que les écouvillons nasaux sont les échantillons à privilégier pour la détection du MERS-CoV par RTPCR chez les dromadaires asymptomatiques.

Es preciso investigar más a fondo el coronavirus del síndrome respiratorio de Oriente Medio (MERS-CoV), recién identificado, que provoca una grave enfermedad respiratoria, sobre todo en personas con afecciones concomitantes. Estudios realizados en Qatar y otros lugares han deparado pruebas de que los dromedarios son un reservorio del virus, pero aún no están del todo claros los modelos exactos de transmisión del MERS-CoV al ser humano. Los autores describen un análisis realizado en febrero de 2014 de la idoneidad y sensibilidad de distintos tipos de muestra para detectar el MERS-CoV mediante una reacción en cadena de la polimerasa acoplada a transcripción inversa en tiempo real (RTPCR) dirigida contra tres genes: el gen UpE (upstream of the E gene: en dirección 5' desde el gen E); el gen N (nucleocápside) y el marco de lectura abierto (ORF) 1a. Para ello se tomaron muestras de 53 animales enviados al sacrificio. Se comprobó que un elevado porcentaje de los dromedarios analizados (un 79% [intervalo de confianza al 95%: 66,9­91,5%; error estándar: 0,0625], esto es, 42 de 53) excretaban virus en el momento del sacrificio, pese a que todos los animales parecían estar sanos. Entre los ejemplares positivos para el MERS-CoV, las muestras que con más frecuencia arrojaban resultado positivo eran los frotis nasales (97,6%). Las segundas, por orden de frecuencia, eran los frotis bucales (35,7%), seguidos de los frotis rectales (28,5%). Además, la carga viral más alta, expresada por un valor de ciclo umbral (Ct) (o punto de cruce) de 11,27, se obtuvo a partir de un frotis nasal. Estos resultados llevan a la conclusión de que los frotis nasales son el tipo de muestra más adaptado para detectar el MERS-CoV en dromedarios aparentemente sanos mediante la técnica de RT-PCR.

Middle East respiratory syndrome coronavirus (MERS-CoV) RNA and neutralising antibodies in milk collected according to local customs from dromedary camels, Qatar, April 2014.

Antibodies to Middle East respiratory syndrome coronavirus (MERS-CoV) were detected in serum and milk collected according to local customs from 33 camels in Qatar, April 2014. At one location, evidence for active virus shedding in nasal secretions and/or faeces was observed for 7/12 camels; viral RNA was detected in milk of five of these seven camels. The presence of MERS-CoV RNA in milk of camels actively shedding the virus warrants measures to prevent putative food-borne transmission of MERS-CoV.

Relationship between mammography breast density and bone mineral density.

Mammography breast density (MBD) is a well-established and strong predictive risk factor for breast cancer. Bone mineral density (BMD) is another predictor of breast cancer risk in women. Both MBD and BMD are linked to a common pathway, which involves estrogens, and are highly heritable. This study evaluated the relationship between MBD and hip and spine BMD in Kuwaiti women. Mammograms and BMD data of 248 women were studied. BMD was measured at total lumbar spine (L1-L4) and total left hip using dual-energy X-ray absorptiometry. The women were classified into 3 groups: normal, osteopenia, and osteoporosis by their BMD, using the World Health Organization criteria. They were divided into another 4 groups: fatty, fibroglandular, heterogeneously dense, and extremely dense breast according to their MBD and as defined by the Breast Imaging Reporting and Data System. All MBD and BMD data were analyzed statistically. Statistical analysis showed no significant difference or correlation between the MBD and BMD groups even after adjusting for obesity and menopausal status. However, a highly significant difference in body weight was found among the MBD groups (p<0.005). No correlation between MBD and BMD was observed in the group of Kuwaiti women who took part in the present study.