Influence of Immediate Dentin Sealing on Marginal Gaps of Laminate Veneers: Machinable Monolithic Zirconia Versus Pressable Lithium Dislocate. An In Vitro Study.

PURPOSE: To investigate the influence of immediate dentin sealing (IDS) vs delayed dentin sealing (DDS) on the marginal gaps of machinable monolithic zirconia (MMZ) vs pressable lithium disilicate (PLD) laminate veneers. MATERIALS AND METHODS: A total of 40 maxillary lateral incisors were used and received butt-joint laminate veneer preparation. The samples were divided into two groups (n = 20 each) according to ceramic material: PLD ceramic was used in the first group, and MMZ was used in the second. Each group was then divided into two subgroups according to the bonding protocol: IDS was employed in one, and DDS in the other (n = 10 each). The marginal gap widths were measured using digital microscopy and statistically analyzed. RESULTS: The smallest marginal gaps were observed in MMZ-DDS (57.2 ± 8.4 µm), followed by PLD-DDS (62.4 ± 2.7 µm) and MMZ-IDS (63.5 ± 1.9 µm). The largest marginal gaps were observed in PLD-IDS (81.5 ± 6.3 µm). Two-way ANOVA revealed that the bonding technique (P < .001) and ceramic material (P < .001) both showed significant differences. CONCLUSIONS: MMZ produced beIer marginal accuracy than PLD. IDS seems to have a predisposition to significantly wider marginal gaps than DDS, but these gaps are within the clinically acceptable range. The marginal accuracy of ceramic veneers appears to be related to the bonding technique as well as the material of construction.

Influence of Immediate Dentin Sealing on the Marginal Gaps of Laminate Veneers: Machinable Monolithic Zirconia Versus Pressable Lithium Disilicate: An in vitro study.

PURPOSE: To investigate the influence of immediate dentin sealing (IDS) vs delayed dentin sealing (DDS) on the marginal gaps of machinable monolithic zirconia vs pressable lithium disilicate laminate veneers. MATERIALS AND METHODS: A total of 40 maxillary lateral incisors were used and received butt-joint laminate veneer preparation. The samples were divided into two groups (n = 20 each) according to ceramic material: pressable lithium disilicate ceramic (PLD) was used in the first group, and machinable monolithic zirconia (MMZ) was used in the second. Each group was then divided into two subgroups according to the bonding protocol: IDS was employed in one, and DDS in the other (n = 10 each). The marginal gap widths were measured using digital microscopy and statistically analyzed. RESULTS: The smallest marginal gaps were observed in MMZ-DDS (57.2 ± 8.4 µm), followed by PLD-DDS (62.4 ± 2.7 µm) and MMZ-IDS (63.5 ± 1.9 µm). The largest marginal gaps were observed in PLD-IDS (81.5 ± 6.3 µm). Two-way ANOVA revealed that the bonding technique (P < .001) and ceramic material (P < .001) both showed significant differences. CONCLUSIONS: MMZ produced better marginal accuracy than PLD. IDS seems to have a predisposition to significantly wider marginal gaps than DDS, but these gaps are within the clinically acceptable range. The marginal accuracy of ceramic veneers appears to be related to the bonding technique as well as the material of construction.

Current Strategies to Control Recurrent and Residual Caries with Resin Composite Restorations: Operator- and Material-Related Factors.

This review addresses the rationale of recurrent and/or residual caries associated with resin composite restorations alongside current strategies and evidence-based recommendations to arrest residual caries and restrain recurrent caries. The PubMed and MEDLINE databases were searched for composite-associated recurrent/residual caries focusing on predisposing factors related to materials and operator's skills; patient-related factors were out of scope. Recurrent caries and fractures are the main reasons for the failure of resin composites. Recurrent and residual caries are evaluated differently with no exact distinguishment, especially for wall lesions. Recurrent caries correlates to patient factors, the operator's skills of cavity preparation, and material selection and insertion. Material-related factors are significant. Strong evidence validates the minimally invasive management of deep caries, with concerns regarding residual infected dentin. Promising technologies promote resin composites with antibacterial and remineralizing potentials. Insertion techniques influence adaptation, marginal seal, and proximal contact tightness. A reliable diagnostic method for recurrent or residual caries is urgently required. Ongoing endeavors cannot eliminate recurrent caries or precisely validate residual caries. The operator's responsibility to precisely diagnose original caries and remaining tooth structure, consider oral environmental conditions, accurately prepare cavities, and select and apply restorative materials are integral aspects. Recurrent caries around composites requires a triad of attention where the operator's skills are cornerstones.

Matrix Metalloproteinases in Dental and Periodontal Tissues and Their Current Inhibitors: Developmental, Degradational and Pathological Aspects.

OBJECTIVES: This review article aims to describe some of the roles of Matrix metalloproteinases (MMPs) in enamel, dentine, dental caries, hybrid layer degradation, pulp and periodontal tissues, throwing light on their current inhibitors. The article addresses the potential of MMPs to serve as biomarkers with diagnostic and therapeutic value. DESIGN: The sections of this review discuss MMPs' involvement in developmental, remodeling, degradational and turnover aspects of dental and periodontal tissues as well as their signals in the pathogenesis, progress of different lesions and wound healing of these tissues. The literature was searched for original research articles, review articles and theses. The literature search was conducted in PubMed and MEDLINE for articles published in the last 20 years. RESULTS: 119 published papers, two textbooks and two doctoral theses were selected for preparing the current review. CONCLUSIONS: MMPs are significant proteases, of evident contribution in dental and periapical tissue development, health and disease processes, with promising potential for use as diagnostic and prognostic disease biomarkers. Continuing understanding of their role in pathogenesis and progress of different dental, periapical and periodontal lesions, as well as in dentine-pulp wound healing could be a keystone to future diagnostic and therapeutic regimens.

A cross-sectional multicenter survey on the future of dental education in the era of COVID-19: Alternatives and implications.

PURPOSE: The coronavirus disease 2019 (COVID-19) pandemic has significantly challenged dental education. This study investigated the procedures outlined by dental faculty members to maintain quality dental education in a safe bioenvironment and adequately control the risk of cross-infection METHOD: Dental educators from dental schools around the world were invited to join an online survey considering different demographic factors. The survey consisted of 31 questions that were classified into separate sections, including academic characteristics, college size and facilities, action taken after announcement of the COVID-19 pandemic, perception of the pandemic, opinion regarding teaching, patient flow, possible facilities to implement for short- and long-term plans, and actions suggested to deal with the COVID-19 pandemic RESULTS: Two hundred-twelve responses were received. Respondents commonly agreed that COVID-19 will have major negative effects on dental education, adversely affecting all clinical disciplines. Shifting to virtual curricula, simulation labs, and distant learning were the prevailing actions taken in different dental colleges during the pandemic. Special attention was raised by the majority of respondents regarding dental aerosolizing procedures, preferring to postpone their training to a postpandemic/later phase. Coinciding opinions suggested adopting a future dynamic hybrid strategy analysis that combines online distant learning, virtual simulation, and haptic labs together with traditional direct clinical training on real patients CONCLUSION: The future of dental education will have far-reaching changes in strategies and tools to cope with COVID-19 pandemic and the postpandemic requirements of an effective, yet safe, dental learning environment. Dental colleges need to invest in infection precautions and in modern virtual education and training facilities.