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Newly introduced provisional crowns and fixed dental prostheses (FDP) materials should exhibit good physical and mechanical properties necessary to serve the purpose of their fabrication. The aim of this systematic literature review and meta-analysis is to evaluate the articles comparing the physical and mechanical properties of 3D-printed provisional crown and FDP resin materials with CAD/CAM (Computer-Aided Designing/Computer-Aided Manufacturing) milled and conventional provisional resins. Indexed English literature up to April 2022 was systematically searched for articles using the following electronic databases: MEDLINE-PubMed, Web of Science (core collection), Scopus, and the Cochrane library. This systematic review was structured based on the guidelines given by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The focused PICO/PECO (Participant, Intervention/exposure, Comparison, Outcome) question was: ‘Do 3D-printed (P) provisional crowns and FDPs (I) have similar physical and mechanical properties (O) when compared to CAD/CAM milled and other conventionally fabricated ones (C)’. Out of eight hundred and ninety-six titles, which were recognized after a primary search, twenty-five articles were included in the qualitative analysis, and their quality analysis was performed using the modified CONSORT scale. Due to the heterogeneity of the studies, only twelve articles were included for quantitative analysis. Within the limitations of this study, it can be concluded that 3D-printed provisional crown and FDP resin materials have superior mechanical properties but inferior physical properties compared to CAD/CAM milled and other conventionally fabricated ones. Three-dimensionally printed provisional crowns and FDP materials can be used as an alternative to conventional and CAD/CAM milled long-term provisional materials.

Increasing demands for aesthetically pleasing dental restorations have promoted the use of materials that display superior optical properties. Zirconia-based all-ceramic systems have good optical properties, thus providing the desired esthetics for dental restorations. The altered oral conditions impact the physical properties of these materials. Multiple studies have been conducted to evaluate the effect of aging on the mechanical properties of computerized-aided design and computerized-aided manufacturing (CAD/CAM)-based zirconia; however, there is a scarcity of literature discussing the effect of aging on change in translucency, contrast ratio, and color. Therefore, this research aimed to evaluate the effect of accelerated artificial aging on translucency parameter (TP), contrast ratio (CR), and color of CAD/CAM zirconia at different sintering temperatures. Twenty-eight rectangular-shaped specimens were obtained by CAD/CAM milling of zirconia blank. Sintering of the samples was carried out at four different temperatures 1350 °C, 1400 °C, 1450 °C, and 1500 °C, respectively. Thermocycling of the samples was performed in a thermocycler. TP, CR, and color evaluation of all the samples was done again using a Spectrophotometer. Data acquired were statistically evaluated by one-way ANOVA and Post Hoc test. The highest amount of change in TP was recorded for specimens sintered at 1400 °C (1.86), whereas the least change was attributed to 1350 °C (0.51). The highest change in CR was observed in specimens sintered at 1500 °C (0.0971), and the least change in CR was observed at 1450 °C (0.0086). The highest ΔE values were recorded for 1400 °C against both white (1.86) and black background (2.17), whereas the least change was attributed to 1350 °C against white (0.86) and against a black background (1.41). The changes in TP were significant, but CR did not show any significant change. ΔE values for all the experimental groups were significant, but were below the clinically perceptible range. An increase in sintering temperature increased the translucency.

Vacuum-formed retainers (VFRs) are widely used in dental practices because of their superior esthetics. However, simultaneous maintenance of their hygiene, mechanical and optical properties is challenging. This study aimed to evaluate and compare the disinfection efficacy of antimicrobial photodynamic therapy (aPDT), chlorhexidine (CHX), sodium hypochlorite (NaOCl) and water over VFRs specimens, along with their effect on flexural strength and color stability.Fabricated VFRs of thicknesses 1 mm and 2 mm were contaminated with S. mutans and C. albicans. Brain Heart Infusion agar was used to seed Streptococcus Mutans whereas Candida Albicans was seeded in Sabourand Dextrose Agar. The contaminated retainers were divided into four groups and decontaminated using four different treatment protocols: aPDT, CHX, NaOCl and water, with 10 specimens per group. Microbial viability following decontamination, was assayed using MTT. To assess the color stability, pre and post decontamination color difference of 10 specimens was recorded using a spectrophotometer by blinding technique. The flexural strength of 10 specimens was measured using a universal testing machine by a standardized 3-point flexural strength (FS) test.aPDT showed the highest reduction in the viability of S. mutans (28%) and C. albicans (20%) species in 1 mm thickness group while the second highest reduction following disinfection with CHX (40%) in followed by NaOCl disinfection (50%). On comparison between 1 mm and 2 mm, a statistically significant difference was noted for S. mutans in aPDT (p = 0.033) and NaOCl (p = 0.028) groups, and for C. albicans, a significant difference was noted within NaOCl (p = 0.001) and CHX (p = 0.043) groups. For FS, a statistically significant difference (p 0.05) was observed between aPDT and the rest of the groups, whereas there was no statistically significant difference in the flexural strength between the CHX, NaOCl and water groups (p 0.05) in both 1 mm and 2 mm specimens. Between 1 mm and 2 mm specimens, no statistically significant difference in the mean color difference was noted after any disinfection protocol (p 0.05).Antimicrobial photodynamic therapy showed a remarkable reduction in candidal and bacterial viability over VFRs. aPDT treated VFR specimens showed increased flexural strength and a higher color difference post treatment compared to other reagents.

Amidst growing technological advancements, newer denture base materials and polymerization methods have been introduced. During fabrication, certain mechanical properties are vital for the clinical longevity of the denture base. This systematic review aimed to explore the effect of newer denture base materials and/or polymerization methods on the mechanical properties of the denture base. An electronic database search of English peer-reviewed published papers was conducted using related keywords from 1 January 2011, up until 31 December 2021. This systematic review was based on guidelines proposed by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The search identified 579 papers. However, the inclusion criteria recognized 22 papers for eligibility. The risk of bias was moderate in all studies except in two where it was observed as low. Heat cure polymethyl methacrylate (PMMA) and compression moulding using a water bath is still a widely used base material and polymerization technique, respectively. However, chemically modified PMMA using monomers, oligomers, copolymers and cross-linking agents may have a promising result. Although chemically modified PMMA resin might enhance the mechanical properties of denture base material, no clear inferences can be drawn about the superiority of any polymerization method other than the conventional compression moulding technique.

This study assessed the potential of riboflavin-mediated photodynamic therapy (RF-PDT) against Candida albicans (C. albicans) and compared the effects of RF-PDT with other therapeutic modalities in terms of mechanical and surface characteristics of acrylic denture base material.Molds (10 × 10 × 2 mm) of acrylic resin specimens were prepared and underwent artificial ageing. C. albicans were grown aerobically over the specimens and divided into four groups (n = 10/group); Group-I: no decontamination; Group-II: nystatin suspension; Group-III: riboflavin 0.1% in darkness, Group-IV: blue LED light only, and Group-V: riboflavin 0.1% for 10 minutes (pre-irradiation time) and photoactivated by the blue LED light (light dose). Fungal viability was assessed using MTT assay and characterized using scanning electron microscopy and confocal laser microscopy (CLSM). Treated specimens were subjected to surface roughness (RGroup-I showed the highest C. albicans viability followed by Group-III. Nystatin group (Group-II) showed ∼50% of the viability while RF-PDT showed the least C. albicans viability among the four groups (p0.05). On SEM, specimens treated with Group-IV and V showed almost clear and free from C. albicans that was evidenced on CLSM. Post-treated specimens and storage after 72 h revealed that FS was significantly higher for RF-PDT group as compared to any other group (105.82 MPa) (p0.05). The FM and Ra showed statistically no significant difference between the groups (p0.05).RF-PDT showed the highest anti-fungal capacity against C. albicans over acrylic denture surface without any surface deterioration.