Clinical Outcomes of CAD/CAM (Lithium disilicate and Zirconia) Based and Conventional Full Crowns and Fixed Partial Dentures: A Systematic Review and Meta-Analysis.

Although CAD/CAM (computer-aided design/computer-aided manufacturing) restorations act as a favorable alternative to conventional metal-ceramic restorations for fixed dental prostheses, little is known about their intermediate and persistent clinical performance. This systematic review and meta-analysis aimed to assess the clinical performance in terms of biological, technical, and esthetic aspects and the survival and success ratios for single full crowns (SFCs) and fixed partial dentures (FPDs) fabricated by CAD/CAM and conventional techniques and according to the materials used (zirconia {ZC} and lithium disilicate {LD}). The population, intervention, control, outcome, and study design (PICOS) strategy was used to electronically search key terms in the PubMed, Cochrane Library, Embase, and Wiley Online databases for randomized control trials (RCTs) and cohort studies. The bias risks for RCTs and cohort studies were assessed using the Cochrane collaboration tool and the Newcastle-Ottawa Scale (NOS). Meta-analysis was performed using Rev5 from Cochrane. A total of 13 studies reporting on 1598 restorations in 1161 patients with a mean observation period of 3.6 years (minimum-maximum: 1-9.3 years) met the inclusion criteria. Meta-analysis of the included studies indicated that CAD/CAM manufacturing resulted in 1.17, 1.14, and 16.88 (95% CI: 0.64-2.17, 0.86-1.52, 7.59-37.56) higher biological, technical, and esthetic complications than conventional manufacturing of restorations. However, the difference was significant for esthetic complications only (p<0.00001). A significant difference was observed for all biological, technical, and aesthetic aspects between SFCs and FPDs (odds ratio {OR} = 2.61 vs. 1.78, 95% CI: 1.92-3.56 vs. 1.33-2.38; p<0.00001). The survival ratio of SFCs was 2.69 (95% CI: 1.98-3.65), significantly higher compared to the 1.76 (95% CI: 1.31-2.36) of FPDs (p<0.00001). The success ratio of FPDs at 1.18 (95% CI: 0.83-1.69) was significantly lower compared to SFCs at 2.36 (95% CI: 1.68-3.33). The clinical performance of LD with 2.42 (CI: 1.16-5.03) was significantly higher compared to ZC with 2.22 (CI: 1.78-2.77) (p<0.00001). The biological, technical, and aesthetic behaviors showed similar clinical outcomes between the CAD/CAM and conventional groups. LD could be a good alternative to zirconia, but its intermediate or persistent clinical performance needs to be evaluated. Overall, zirconia and CAD/CAM techniques must evolve further to outclass the conventional techniques used in the fabrication of SFCs and FPDs.

Diagnosis and management of mucormycosis in the dental clinic: A guide for oral health professionals in India.

With the current pandemic raging over the world, science and medicine is faced with hereto with unfought enemies or less fought opponent in the form of viruses and consequently, other biotic entities. While researchers are striving to identify and conquer the variants of COVID-19, other innocuous organisms are raising their ugly heads in the form of opportunistic fungal infections. Mucormycosis/Black Fungus is an invasive opportunistic fungal infection caused by mucorale species. It spreads through blood vessels causing thrombosis, ischemia, and necrosis. Population with pre-existing immunocompromised conditions such as Diabetes Mellitus, Malignancy, Long-term immunosuppressant therapy are more susceptible. Mucormycosis associated with Corona Virus Disease-2019 (COVID-19) proved to be catastrophic due to its high mortality rates. Rhino orbital Mucormycosis is the most common form. The primary care physician, being the first and often, (more so in developing countries) and being the only point of contact with a healthcare professional, plays a pivotal role in the diagnosis and management of this condition. The keystone to decreasing mortality is early detection and diagnosis followed by preventive measures to control progression to the brain. A multidisciplinary approach by various specialties is a prerequisite for effective diagnosis and management. Antifungal therapy, surgical debridement, and resection of the affected areas are protocols to be followed. Post-operative defects cause impairment of function, phonetics, and esthetics. Prosthetic rehabilitation of these defects has shown favorable results, especially in the aged and immunocompromised individuals.

An esthetic modification of a nasal conformer.

Facial contractures caused by burns can collapse the nasal aperture and lead to airway obstruction. Management in such situations requires surgical and prosthetic intervention. Prosthetically, although a nasal conformer is the treatment of choice, even a well-fabricated nasal conformer may be esthetically unappealing and require an aid for enhanced retention. Expensive implant-aided conformers are not always a viable option. This article introduces a technique for fabricating a nasal conformer that is both esthetically appealing and cost-effective. The technique is illustrated by the treatment of a 12-year-old girl who presented with a history of burn injuries leading to nasal contracture that was effectively managed with this concept.

Evidence that ferritin is associated with light production in the mucus of the marine worm Chaetopterus.

The blue glow of the mucus from Chaetopterus involves a photoprotein, iron and flavins. Identity and respective role of these components remain, however, largely unresolved today, likely because of viscosity issues and inhibition of this system by oxidizers conventionally used to track bioluminescence activity. Here, we used gentle centrifugation to obtain a mucus supernatant showing no inhibition to oxidizers, allowing for further analysis. We applied conventional chromatographic techniques to isolate major proteins associated with light emission. Luminescence ability of elutriate fractions was tested with hydrogen peroxide to track photoprotein and/or protein-bound chromophore. Fractions producing light contained few major proteins, one with similarity to ferritin. Addition to the mucus of elements with inhibitory/potentiary effect on ferritin ferroxidase activity induced corresponding changes in light production, emphasizing the possible role of ferritin in the worm bioluminescence. DNA of the protein was cloned, sequenced, and expressed, confirming its identity to a Chaetopterus Ferritin (ChF). Both ferric and ferrous iron were found in the mucus, indicating the occurrence of both oxidase and reductase activity. Biochemical analysis showed ChF has strong ferroxidase activity, which could be a source of biological iron and catalytic energy for the worm bioluminescence when coupled to a reduction process with flavins.

Identification and characterization of the missing phosphatase on the riboflavin biosynthesis pathway in Arabidopsis thaliana.

Despite the importance of riboflavin as the direct precursor of the cofactors flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN), the physiologically relevant catalyst dephosphorylating the riboflavin biosynthesis pathway intermediate 5-amino-6-ribitylamino-2,4(1H,3H) pyrimidinedione 5'-phosphate (ARPP) has not been characterized from any organism. By using as the query sequence a previously identified plastidial FMN hydrolase AtcpFHy1 (At1g79790), belonging to the haloacid dehalogenase (HAD) superfamily, seven candidates for the missing ARPP phosphatase were found, cloned, recombinantly expressed, and purified. Activity screening showed that the enzymes encoded by AtcpFHy1, At4g11570, and At4g25840 catalyze dephosphorylation of ARPP. AtcpFHy1 was renamed AtcpFHy/PyrP1, At4g11570 and At4g25840 were named AtPyrP2 and AtGpp1/PyrP3, respectively. Subcellular localization in planta indicated that AtPyrP2 was localized in plastids and AtGpp1/PyrP3 in mitochondria. Biochemical characterization of AtcpFHy/PyrP1 and AtPyrP2 showed that they have similar Km values for the substrate ARPP, with AtcpFHy/PyrP1 having higher catalytic efficiency. Screening of 21 phosphorylated substrates showed that AtPyrP2 is specific for ARPP. Molecular weights of AtcpFHy/PyrP1 and AtPyrP2 were estimated at 46 and 72 kDa, suggesting dimers. pH and temperature optima for AtcpFHy/PyrP1 and AtPyrP2 were ~7.0-8.5 and 40-50°C. T-DNA knockout of AtcpFHy/PyrP1 did not affect the flavin profile of the transgenic plants, whereas silencing of AtPyrP2 decreased accumulation of riboflavin, FMN, and FAD. Our results strongly support AtPyrP2 as the missing phosphatase on the riboflavin biosynthesis pathway in Arabidopsis thaliana. The identification of this enzyme closes a long-standing gap in understanding of the riboflavin biosynthesis in plants.

Chemical Analysis of the Luminous Slime Secreted by the Marine Worm Chaetopterus (Annelida, Polychaeta).

The marine annelid Chaetopterus variopedatus produces bioluminescence by an unknown and potentially novel mechanism. We have advanced the study of this fascinating phenomenon, which has not been investigated for nearly 60 years after initial studies were first reported for this species. Here, we show that the luminous slime produced by the worm exhibits blue fluorescence that matches the bioluminescence emission. This result suggests that the oxyluciferin emitter is present. However, while the blue fluorescence decays over time green fluorescence is increasingly revealed that is likely associated with products of the luminescence reaction. LC/MS and fluorescence analysis of harvested luminescent material revealed riboflavin as the major green fluorescent component. Riboflavin is usually associated with the mechanism of light production in bacteria, yet luminous bacteria were not found in the worm mucus, and accordingly were not reported to be directly responsible for the light emission, which is under nervous control in the worm. We therefore propose a hypothesis in which riboflavin or a structurally related derivative serves as the emitter in the worm's light producing reaction.

An FMN hydrolase of the haloacid dehalogenase superfamily is active in plant chloroplasts.

FMN hydrolases catalyze dephosphorylation of FMN to riboflavin. Although these enzymes have been described in many organisms, few had their corresponding genes cloned and their recombinant proteins biochemically characterized, and none had their physiological roles determined. We found previously that FMN hydrolase activity in pea chloroplasts is Mg(2+)-dependent, suggesting an enzyme of the haloacid dehalogenase (HAD) superfamily. In this study, a new FMN hydrolase was purified by multistep chromatography after ammonium sulfate precipitation. The molecular weight of the native protein was estimated at ∼59,400, a dimer of about twice the predicted molecular weight of most HAD superfamily phosphatases. After SDS-PAGE of the partially purified material, two separate protein bands within 25-30 kDa were extracted from the gel and analyzed by nanoLC-MS/MS. Peptide sequence matching to the protein samples suggested the presence of three HAD-like hydrolases. cDNAs for sequence homologs from Arabidopsis thaliana of these proteins were expressed in Escherichia coli. Activity screening of the encoded proteins showed that the At1g79790 gene encodes an FMN hydrolase (AtcpFHy1). Plastid localization of AtcpFHy1 was confirmed using fluorescence microscopy of A. thaliana protoplasts transiently expressing the N-terminal fusion of AtcpFHy1 to enhanced green fluorescent protein. Phosphatase activity of AtcpFHy1 is FMN-specific, as assayed with 19 potential substrates. Kinetic parameters and pH and temperature optima for AtcpFHy1 were determined. A phylogenetic analysis of putative phosphatases of the HAD superfamily suggested distinct evolutionary origins for the plastid AtcpFHy1 and the cytosolic FMN hydrolase characterized previously.

Application of microwave energy in the manufacture of enhanced-quality green tea.

Green tea manufacture was standardized with respect to the inactivation of polyphenol oxidase (PPO), rolling, and drying for quality manufacture. Inactivation of PPO by parching, steaming, microwave heating, and oven heating was monitored in tea shoots. The inactivated shoots were rolled under regimens of high and low pressures and dried by microwave heating, oven heating, or sun-drying; total phenols and catechins were estimated. Parched and sun-dried teas contained the lowest levels of total phenols and catechins, and their infusions were dull in color with a slightly burnt odor. Microwave-inactivated and-dried teas showed the highest levels of total phenols and catechins, and their infusions were bright in color and sweet in taste with a subtle pleasant odor. In steam-inactivated and oven/microwave-dried teas, total phenol and catechin contents were intermediate between parched and sun-dried teas and microwave-inactivated and microwave-dried teas, and their infusions were bright with a umami taste.