Computational analysis of 3D printing: Selecting the better among newly released materials.

Resin-based three-dimensional (3D) printing finds extensive application in the field of dentistry. Although studies of cytotoxicity, mechanical and physical properties have been conducted for newly released 3D printing resins such as Crowntec (Saremco), Temporary Crown Resin (Formlabs) and Crown & Bridge (Nextdent), the resistance of these materials to esterases in saliva has not been demonstrated at the molecular level. Therefore, in this study, the binding affinities and stability of these new 3D printing resins to the catalytic sites of esterases were investigated using molecular docking and molecular mechanics with Poisson-Bolzmann and surface area solvation (MM/PBSA) methods after active pocket screening. Toxicity predictions of the materials were also performed using ProTox-II and Toxtree servers. The materials were analyzed for mutagenicity, cytotoxicity, and carcinogenicity, and LD50 values were predicted from their molecular structures. The results indicated that out of the three novel 3D printing materials, Nexdent exhibited reduced binding affinity to esterases, indicating enhanced resistance to enzymatic degradation and possessing a superior toxicity profile.

Using Resin Infiltration Technique and Direct Composite Restorations for the Treatment of Carious Lesions with Different Depths.

Minimally invasive treatment methods are of special interest in restorative dental practice, with numerous methods emerging in the last decade. Such methods are being developed to encompass various applications, an important one being the detection and treatment of caries in the early stages. White spot lesions are the earliest visible stage of the caries process. These lesions have a chalky, opaque appearance, which results in esthetic dissatisfaction. In contrast to the principles of minimally invasive dentistry, considerable amounts of sound tooth structure need to be sacrificed to get rid of these lesions. Therefore, caries infiltration has been introduced as an alternative treatment option for non-cavitated lesions. The resin infiltration technique only works in non-cavitated lesions. Replacement of lost dental tissue with resin composites remains the mainstay therapy in cases with cavity formation. This case report describes a case of caries with lesions of varying depths. In such cases, a combination of treatment methods may be used to provide satisfying esthetics with a minimally invasive approach.

Comparison of Different Restoration Techniques for Endodontically Treated Teeth.

The aim of the present study is to evaluate the physical properties of endodontically treated teeth restored with five different restorative techniques and materials. Hundred and forty extracted human molar teeth were used. In addition to five restoration groups, specimens with no restorations were used as the negative control, and intact molar teeth were used as the positive control. For flexural strength tests, material specimens were made from 5 different materials using a mould according to ISO 4049 standards. One-way ANOVA revealed that the fracture resistance was significantly affected by the restoration type. SFRC group showed the best fracture resistance values, while lowest values were seen in the GWF group. The test results of flexural strength showed values between 140 and 184 MPa and modulus of elasticity between 6.33 and 18.89 GPa (p < 0.05). Under the limits of this study, results showed that SFRC can be used to increase the fracture resistance of ETT.

Saliva: Both a Threat and an Opportunity in Covid-19 Pandemic.

Covid-19 pandemic, continues all over the world with the increasing number of confirmed cases and performed tests day by day. It has been shown that collecting nasopharyngeal samples, as the most commonly prefered method to perform RT-PCR, has disadvantages like causing discomfort and bleeding in patients. Sample collecting procedure also renders healthcare professionals by exposing them to the risk of transmission of the virus related to the direct contact with patients. These disadvantages make this procedure undesirable for the researchers and forces them to search for an alternative technique. At this point, saliva appears as an opportunity, regarding its high viral load. On the other hand, this high viral load poses a threat, especially for professions such as dental practitioners, with too much aerosol exposure. Since dentistry is a branch of health that constantly needs direct operations, it is necessary to be protected from the virus as much as possible while caring for the patient. A literature review was done using electronic databases "PubMed," "Google Scholar," and "Cochrane Database," on January 2021. Studies have proposed many different preventive measures in this regard. Therefore, the purpose of this review is to draw attention to the saliva by bringing together the recent research and also to provide information and a perspective to dental clinicians about both prevention and a potential diagnostic technique.