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Journal of Dentistry Aug 2020To identify antibacterial additives and screening/assessment approaches used to evaluate the antibacterial activity of resin-based restorative dental materials... (Review)
Review
OBJECTIVES
To identify antibacterial additives and screening/assessment approaches used to evaluate the antibacterial activity of resin-based restorative dental materials containing these additives.
DATA
In vitro studies that compared the antibacterial effects of resin-based restorative dental materials with and without antibacterial additives were screened. Risk bias was assessed, and the following data were extracted: antibacterial additive, parental dental material, curing mode, bacterial growth outcome assessment, samples used as a substrate for bacterial growth, inoculum complexity, and culture time as an indicator of biofilm maturity.
SOURCE
Arksey and O'Malley's five stages framework using Medline (OVID), EMBASE, and Scopus (Elsevier) databases guided this review.
STUDY SELECTION
From 6503 studies initially identified, 348 studies were considered eligible for full-text screening, and 153 were included for data extraction. Almost all studies have a high sampling bias related to both sample size and blindness. Quaternary ammonium monomers were the most investigated additive (45 %), and the most prevailing parental material was resin composite (49 %). There was extensive methodological heterogeneity among the studies for outcome assessment with the majority using resin composite disks (78 %), mono-species Streptococcus mutans as the inoculum (54 %), and a relatively short period of biofilm growth (≤24 h).
CONCLUSION
The findings herein present the urgent need for improved biological efficacy studies in this important and exciting field. There is a need for efforts to improve study designs to mimic the oral environment in vivo and to develop standardized methods to help understand and optimize these materials.
CLINICAL SIGNIFICANCE
Most studies that incorporate antibacterial additives into resin-based materials claim promising results by bacterial reduction. However, these results should be interpreted with caution due to significant variation in the methods applied for quantifying bacterial growth, the frequent lack of complexity in the biofilms, and the often-short duration of biofilm growth.
Topics: Anti-Bacterial Agents; Biofilms; Composite Resins; Dental Materials; Materials Testing; Streptococcus mutans
PubMed: 32387506
DOI: 10.1016/j.jdent.2020.103369 -
Journal of the American Dental... Jan 2021Zirconia is a relatively new dental material used for indirect dental restorations. Little is known about how dental practitioners are using this material in their...
BACKGROUND
Zirconia is a relatively new dental material used for indirect dental restorations. Little is known about how dental practitioners are using this material in their practice.
METHODS
A survey on zirconia restorations was developed and administered electronically through e-mail communications to the American Dental Association Clinical Evaluators (ACE) Panel on August 31, 2020. Reminders were sent to nonrespondents, and the survey closed 2 weeks after the launch date.
RESULTS
When using zirconia for a restoration, respondents choose it to restore natural teeth (99%) more often than implants (76%). Almost all respondents (98%) use it for posterior crowns, whereas approximately two-thirds (61%) use it for anterior crowns. Restoration removal or replacement and shade matching and translucency were the top 2 cited disadvantages of zirconia, whereas most of the respondents (57%) cited flexural strength or fracture resistance as the biggest advantage. Fine diamonds and ceramic polishers are used most often to polish and adjust zirconia restorations, whereas coarse diamond rotary instruments and those made specifically for zirconia are most frequently used for removing these restorations. Compared with metal ceramic restorations, more than 50% of respondents experience debonding more often with zirconia restorations.
CONCLUSIONS
Dentists recognize the favorable fracture resistance and flexural strength properties of zirconia, and most use similar techniques when adjusting and removing this material. Removing these restorations and shade matching are a struggle for many.
PRACTICAL IMPLICATIONS
Dentists may benefit from tips on the best methods to remove, shade match, and adhesively bond zirconia restorations.
Topics: American Dental Association; Ceramics; Crowns; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Dental Restoration Failure; Dental Stress Analysis; Dentists; Humans; Professional Role; Surveys and Questionnaires; United States; Zirconium
PubMed: 33250170
DOI: 10.1016/j.adaj.2020.10.012 -
Operative Dentistry 2018Composites can be classified differently, according to manufacturer information, filler particle size, resin-monomer base, or viscosity, for example. Using clinical... (Review)
Review
OBJECTIVES
Composites can be classified differently, according to manufacturer information, filler particle size, resin-monomer base, or viscosity, for example. Using clinical trial data, network meta-analyses aim to rank different composite material classes. Dentists then use these ranks to decide whether to use specific materials. Alternatively, annual failure rates (AFRs) of materials can be assessed, not requiring any classification for synthesis. It is unclear whether different classification systems lead to different rankings of the same material (ie, erroneous conclusions). We aimed to evaluate the agreement of material rankings between different classification systems.
METHODS
A systematic review was performed via MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE. Randomized controlled trials published from 2005-2015 that investigated composite restorations placed in load-bearing cavitated lesions in permanent teeth were included. Network meta-analyses were performed to rank combinations of composite classes (according to manufacturer, filler particle size, resin-monomers, viscosity) and adhesives. Material combinations were additionally ranked using AFRs.
RESULTS
A total of 42 studies (6088 restorations, 2325 patients) were included. The ranking of most material class combinations showed significant agreement between classifications ( R ranged between 0.03 and 0.56). Comparing material combinations using AFRs had low precision and agreement with other systems. AFRs were significantly correlated with follow-up periods of trials.
CONCLUSION
There was high agreement between rankings of identical materials in different classification systems. Such rankings thus allow cautious deductions as to the performance of a specific material. Syntheses based on AFRs might lead to erroneous results because AFRs are determined by follow-up periods and have low precision.
Topics: Composite Resins; Dental Materials; Humans; Network Meta-Analysis
PubMed: 29504879
DOI: 10.2341/16-344-LIT -
Journal of Prosthodontics : Official... Apr 2023To measure the flexural strength and Weibull characteristics of aged and nonaged printed interim dental material fabricated with different layer thickness. (Comparative Study)
Comparative Study
PURPOSE
To measure the flexural strength and Weibull characteristics of aged and nonaged printed interim dental material fabricated with different layer thickness.
MATERIAL AND METHODS
Bars (25×2×2 mm) were additively fabricated by using a polymer printer (Asiga Max) and an interim resin (Nexdent C&B MFH). Specimens were fabricated with the same printing parameters and postprocessing procedures, but with 7 different layer thickness: 50 (control or 50-G group), 10 (10-G group), 25 (25-G group), 75 (75-G group), 100 (100-G group), 125 (125-G group), and 150 μm (150-G group). Two subgroups were created: nonaged and aged subgroups (n = 10). A universal testing machine was selected to measure flexural strength. Two-parameter Weibull distribution values were computed. Two-way ANOVA and Tukey tests were selected for statistical evaluation of the data (α = 0.05).
RESULTS
Artificial aging methods (p < 0.001) were a significant predictor of the flexural strength computed. Aged specimens acquired less flexural strength than nonaged specimens. The Weibull distribution obtained the highest shape for nonaged 50-G and 75-G group specimens compared with those of other nonaged groups, while the Weibull distribution showed the highest shape for aged 125-G specimens.
CONCLUSIONS
The flexural strength of the additively fabricated interim material examined was not influenced by the layer thickness at which the specimens were fabricated; however, artificial aging techniques reduced its flexural strength. Aged specimens presented lower Weibull distribution values compared with nonaged specimens, except for the 125-G specimens.
Topics: Flexural Strength; Dental Materials; Materials Testing; Surface Properties; Stress, Mechanical; Printing, Three-Dimensional; Polymerization; Polymers
PubMed: 35924435
DOI: 10.1111/jopr.13582 -
Investigative Radiology Sep 2023The aim of this study was to compare the effectiveness of common strategies for artifact reduction of dental material in photon-counting detector computed tomography...
Artifact Reduction From Dental Material in Photon-Counting Detector Computed Tomography Data Sets Based on High-keV Monoenergetic Imaging and Iterative Metal Artifact Reduction Reconstructions-Can We Combine the Best of Two Worlds?
OBJECTIVE
The aim of this study was to compare the effectiveness of common strategies for artifact reduction of dental material in photon-counting detector computed tomography data sets.
MATERIALS AND METHODS
Patients with dental material who underwent clinically indicated CT of the neck were enrolled. Image series were reconstructed using a standard and sharp kernel, with and without iterative metal artifact reduction (IMAR) (Qr40, Qr40 IMAR , Qr60, Qr60 IMAR ) at different virtual monoenergetic imaging (VMI) levels (40-190 keV). On representative slice positions with and without dental artifacts, mean and standard deviation of CT values were measured in all series at identical locations. The mean absolute error of CT values ( ) and the artifact index (AIX) were calculated and analyzed focusing on 3 main comparisons: ( a ) different VMI levels versus 70 keV, ( b ) standard versus sharp kernel, and ( c ) nonuse or use of IMAR reconstruction. The Wilcoxon test was used to assess differences for nonparametric data.
RESULTS
The final cohort comprised 50 patients. Artifact measures decreased for VMI levels >70 keV, yet only significantly so for reconstructions using IMAR (maximum reduction, 25%). The higher image noise of the sharp versus standard kernel is reflected in higher AIX values and is more pronounced in IMAR series (maximum increase, 38%). The most profound artifact reduction was observed for IMAR reconstructions (maximum reduction : 84%; AIX: 90%).
CONCLUSIONS
Metal artifacts caused by large amounts of dental material can be substantially reduced by IMAR, regardless of kernel choice or VMI settings. Increasing the keV level of VMI series, on the other hand, only slightly reduces dental artifacts; this effect, however, is additive to the benefit conferred by IMAR reconstructions.
Topics: Humans; Artifacts; Metals; Tomography, X-Ray Computed; Neck; Dental Materials; Algorithms
PubMed: 36897803
DOI: 10.1097/RLI.0000000000000967 -
Dental Materials Journal Feb 2019Polytetrafluoroethylene (PTFE) is chemically stable, non-toxic to humans, highly resistant to heat and chemicals, and has an extremely low coefficient of friction....
Polytetrafluoroethylene (PTFE) is chemically stable, non-toxic to humans, highly resistant to heat and chemicals, and has an extremely low coefficient of friction. Therefore, PTFE is used in medical applications. We focused on the physical properties of PTFE in relation to its application as a material for use in prostheses and dental devices/instruments. PTFE exhibited low wear (approximately 1/3 that of bovine tooth, and 1/2 that of type III gold alloy), low dynamic friction (approximately 1/5 that of the other specimens), low hardness (4.8HV1.0), low coloration, and low bacterial adhesion, compared to other specimens except porcelain in wear and coloration test (p<0.01). These results suggest that PTFE could have applications in some prostheses for provisional and/or permanent use, and dental instruments/devices by providing excellent impact absorption, high wear resistance for maintenance of occlusal vertical dimension and original function, and ease of cleaning.
Topics: Animals; Bacterial Adhesion; Cattle; Color; Dental Instruments; Dental Materials; Dental Porcelain; Dental Prosthesis Design; Hardness; In Vitro Techniques; Materials Testing; Polytetrafluoroethylene; Surface Properties
PubMed: 30381638
DOI: 10.4012/dmj.2018-088 -
Operative Dentistry May 2024
Topics: Humans; Dentistry, Operative; Dental Materials
PubMed: 38807320
DOI: 10.2341/1559-2863-49-3-245 -
Dental Materials : Official Publication... Mar 2016(1) To describe caries lesions development and the role of fluoride in controlling disease progression; (2) to evaluate whether the use of fluoride-releasing pit and... (Review)
Review
OBJECTIVES
(1) To describe caries lesions development and the role of fluoride in controlling disease progression; (2) to evaluate whether the use of fluoride-releasing pit and fissure sealants, bonding orthodontic agents and restorative materials, in comparison to a non-fluoride releasing material, reduces caries incidence in children or adults, and (3) to discuss how the anti-caries properties of these materials have been evaluated in vitro and in situ.
METHODS
The search was performed on the Cochrane Database of Systematic Reviews and on Medline via Pubmed.
RESULTS
Caries is a biofilm-sugar dependent disease and as such it provokes progressive destruction of mineral structure of any dental surface - intact, sealed or restored - where biofilm remains accumulated and is regularly exposed to sugar. The mechanism of action of fluoride released from dental materials on caries is similar to that of fluoride found in dentifrices or other vehicles of fluoride delivery. Fluoride-releasing materials are unable to interfere with the formation of biofilm on dental surfaces adjacent to them or to inhibit acid production by dental biofilms. However, the fluoride released slows down the progression of caries lesions in tooth surfaces adjacent to dental materials. This effect has been clearly shown by in vitro and in situ studies but not in randomized clinical trials.
SIGNIFICANCE
The anti-caries effect of fluoride releasing materials is still not based on clinical evidence, and, in addition, it can be overwhelmed by fluoride delivered from dentifrices.
Topics: Cariostatic Agents; Dental Caries; Dental Materials; Dentin-Bonding Agents; Disease Progression; Fluorides; Humans; Pit and Fissure Sealants
PubMed: 26777115
DOI: 10.1016/j.dental.2015.12.002 -
The Journal of Prosthetic Dentistry Nov 2022The influence of postpolymerization methods and artificial aging procedures on the fracture resistance and flexural strength of additively manufactured interim polymers...
STATEMENT OF PROBLEM
The influence of postpolymerization methods and artificial aging procedures on the fracture resistance and flexural strength of additively manufactured interim polymers remains unclear.
PURPOSE
The purpose of this in vitro study was to evaluate the effect of the conditions (dry and water- and glycerin-submerged) and time (25, 30, 35, 40, and 45 minutes) of postpolymerization methods with and without artificial aging procedures on the fracture resistance and flexural strength of an additively manufactured interim material.
MATERIAL AND METHODS
Bar specimens (25×2×2 mm) were manufactured from an interim resin (NexDent C&B MFH N1) with a 3-dimensional printer (NexDent 5100) as per the manufacturer's recommendations. Three groups were created based on the postpolymerization condition: dry (D group) and submerged in a container with water (W group) or glycerin (G group) inside the ultraviolet polymerization machine (LC-3DPrint Box). Each group was divided into 5 subgroups (D1 to D5, W1 to W5, and G1 to G5) depending on the polymerizing time (25, 30, 35, 40, and 45 minutes) (n=20). Each subgroup was divided into nonaged and aged subgroups. The aged groups were treated in a mastication simulator. Fracture strength was measured on a universal testing machine. The flexural strength was calculated as per International Organization for Standardization (ISO) 10477-2018. The Kolmogorov-Smirnov test demonstrated that data were normally distributed. The 3-way ANOVA test was used to analyze the data (α=.05).
RESULTS
A significant main effect was found on the fracture strength analysis for each of the 3 factors: postpolymerization condition (F[2, 449]=81.00, P<.001), treatment duration (F[4, 449]=2.84, P=.024), and aging procedure (F [1, 449] =7.62, P=.006). The only significant 2-way interaction was between postpolymerization condition and treatment duration (F[8, 449]=3.12, P=.002). Furthermore, a significant main effect was found on the flexural strength for each of the 3 factors including postpolymerization condition (F[2, 449]=82.55, P<.001), treatment duration (F[4, 449]=2.85, P=.024), and artificial aging procedure (F[1, 449]=6.72, P=.010). The only significant 2-way interaction was between postpolymerization condition and treatment duration (F[8, 449]=3.33, P=.001). Dry postconditions at 25 minutes and nonaged procedures obtained the significantly highest fracture resistance and flexural strength values.
CONCLUSIONS
Postpolymerization conditions and duration time affected the fracture resistance and flexural strength of the additively manufactured interim material assessed. Artificial aging procedures significantly decreased the fracture resistance and flexural strength of the additively manufactured interim dental material.
Topics: Flexural Strength; Polymerization; Dental Materials; Materials Testing; Glycerol; Water; Dental Stress Analysis; Pliability
PubMed: 33795163
DOI: 10.1016/j.prosdent.2021.02.017 -
The Journal of Adhesive Dentistry 2020To investigate simulated localized and generalized wear of self-adhesive restorative materials.
PURPOSE
To investigate simulated localized and generalized wear of self-adhesive restorative materials.
MATERIALS AND METHODS
Three commercially available restorative materials and one experimental material with self-adhesive properties were evaluated. The experimental material was tested in both light-cured and self-cured conditions. Activa (A), Fuji II LC (F), and Equia Forte (E) and the experimental material ASAR-MP4 (S) were investigated. Two kinds of wear were simulated in an Alabama wear machine. Localized wear was simulated with a stainless-steel ball bearing antagonist and generalized with a flat-ended stainless-steel cylinder antagonist. The wear challenge was carried out in an aqueous slurry of polymethyl methacrylate beads. Material volume loss was measured on polyvinyl siloxane replicates of each worn surface using a Proscan 2100 noncontact profilometer in conjunction with Proscan and AnSur 3D software.
RESULTS
There were significant differences (p < 0.05) among the materials for both generalized and localized wear. The experimental material in both curing modes exhibited significantly less localized wear than F and A and significantly less generalized wear than F and E.
CONCLUSION
Self-adhesive materials offer unique handling properties for direct placement of posterior restorations in permanent teeth. The experimental material ASAR-MP4 generated similar wear values to the other self-adhesive materials tested.
Topics: Composite Resins; Dental Cements; Dental Materials; Dental Restoration Wear; Glass Ionomer Cements; Materials Testing; Surface Properties
PubMed: 32030376
DOI: 10.3290/j.jad.a43998