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Dental Materials : Official Publication... Jan 2018Clinical studies should be one main aspect underlying dentists' decision-making towards dental materials. Study design, conduct, analysis and reporting impact on the... (Review)
Review
OBJECTIVE
Clinical studies should be one main aspect underlying dentists' decision-making towards dental materials. Study design, conduct, analysis and reporting impact on the usefulness of studies. We discuss problems with current studies and highlight areas where improvement might be possible.
METHODS
Based on systematically and non-systematically collected data, we demonstrate where and why current studies in clinical dentistry deliver less-than-optimal results. Lending from general medicine, we suggest ways forward for clinical dental material science.
RESULTS
Randomized controlled (efficacy) trials remain a major pillar in dental material science, as they reduce selection bias and, if well-designed and conducted, have high internal validity. Given their costs and limited external validity, alternatives like practice-based or pragmatic controlled trials or observational studies can complement the evidence-base. Prior to conduct, researchers should focus on study comparators and setting (answering questions with relevance to clinical dentistry), and pay attention to statistical power, considering the study aim (superiority or non-inferiority trial), the expected event rate, and attrition. Study outcomes should be chosen on the basis of a core outcome set or, if not available, involving patients and other stakeholders. Studies should be registered a priori, and reporting should adhere to standards. Possible clustering should be accounted for during statistical analysis.
SIGNIFICANCE
Many clinical studies in dental material science are underpowered, and of limited validity and usefulness for daily decision-making. Dental researchers should mirror existing efforts in other medical fields in making clinical studies more valid and applicable, thus contributing to better dental care.
Topics: Decision Making; Dental Materials; Dental Research; Dental Restoration, Permanent; Humans; Randomized Controlled Trials as Topic; Research Design
PubMed: 28988780
DOI: 10.1016/j.dental.2017.09.009 -
Pediatrics Oct 2010Dental sealants and composite filling materials containing bisphenol A (BPA) derivatives are increasingly used in childhood dentistry. Evidence is accumulating that BPA... (Review)
Review
CONTEXT
Dental sealants and composite filling materials containing bisphenol A (BPA) derivatives are increasingly used in childhood dentistry. Evidence is accumulating that BPA and some BPA derivatives can pose health risks attributable to their endocrine-disrupting, estrogenic properties.
OBJECTIVES
To systematically compile and critically evaluate the literature characterizing BPA content of dental materials; to assess BPA exposures from dental materials and potential health risks; and to develop evidence-based guidance for reducing BPA exposures while promoting oral health.
METHODS
The extant toxicological literature and material safety data sheets were used as data sources.
RESULTS
BPA is released from dental resins through salivary enzymatic hydrolysis of BPA derivatives, and BPA is detectable in saliva for up to 3 hours after resin placement. The quantity and duration of systemic BPA absorption is not clear from the available data. Dental products containing the bisphenol A derivative glycidyl dimethacrylate (bis-GMA) are less likely to be hydrolyzed to BPA and have less estrogenicity than those containing bisphenol A dimethacrylate (bis-DMA). Most other BPA derivatives used in dental materials have not been evaluated for estrogenicity. BPA exposure can be reduced by cleaning and rinsing surfaces of sealants and composites immediately after placement.
CONCLUSIONS
On the basis of the proven benefits of resin-based dental materials and the brevity of BPA exposure, we recommend continued use with strict adherence to precautionary application techniques. Use of these materials should be minimized during pregnancy whenever possible. Manufacturers should be required to report complete information on the chemical composition of dental products and encouraged to develop materials with less estrogenic potential.
Topics: Benzhydryl Compounds; Dental Materials; Humans; Phenols; Pit and Fissure Sealants; Resins, Synthetic
PubMed: 20819896
DOI: 10.1542/peds.2009-2693 -
PloS One 2016Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting...
BACKGROUND
Sandblasting particles which remain on the surfaces of dental restorations are removed prior to cementation. It is probable that adhesive strength between luting material and sandblasting particle remnants might exceed that with restorative material. If that being the case, blasting particles adhere to sandblasted material surface could be instrumental to increasing adhesive strength like underlying bonding mechanism between luting material and silanized particles of tribochemical silica coating-treated surface. We hypothesize that ultrasonic cleaning of bonding surfaces, which were pretreated with sandblasting, may affect adhesive strength of a resin luting material to dental restorative materials.
METHODS
We therefore observed adhesive strength of resin luting material to aluminum oxide was greater than those to zirconia ceramic and cobalt-chromium alloy beforehand. To measure the shear bond strengths of resin luting material to zirconia ceramic and cobalt-chromium alloy, forty specimens of each restorative material were prepared. Bonding surfaces were polished with silicon abrasive paper and then treated with sandblasting. For each restorative material, 40 sandblasted specimens were equally divided into two groups: ultrasonic cleaning (USC) group and non-ultrasonic cleaning (NUSC) group. After resin luting material was polymerized on bonding surface, shear test was performed to evaluate effect of ultrasonic cleaning of bonding surfaces pretreated with sandblasting on bond strength.
RESULTS
For both zirconia ceramic and cobalt-chromium alloy, NUSC group showed significantly higher shear bond strength than USC group.
CONCLUSIONS
Ultrasonic cleaning of dental restorations after sandblasting should be avoided to retain improved bonding between these materials.
Topics: Dental Materials; Humans; Materials Testing; Mechanical Phenomena
PubMed: 26764913
DOI: 10.1371/journal.pone.0147077 -
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 Mechanical Behavior of... Feb 2024Polymer-infiltrated ceramic network (PICN) materials have gained considerable attention as tooth restorative materials owing to their mechanical compatibility with human...
Polymer-infiltrated ceramic network (PICN) materials have gained considerable attention as tooth restorative materials owing to their mechanical compatibility with human teeth. However, the mechanical strength of contemporary PICN materials is lower than those of conventional resin composites and ceramics. This study aims to develop novel high-strength PICN for use as a dental restorative material. Zirconia-based PICN (EXP) was fabricated using 3 mol% yttria tetragonal polycrystalline zirconia powder and resin monomers via slip casting, followed by sintering and polymer infiltration. Comprehensive analyses of the microstructure, mechanical properties, and physicochemical properties of EXP were performed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, inorganic content measurements, three-point bending test, Vickers hardness test, two-body wear test, shear bond strength (SBS) test, surface free energy analysis, and water sorption/solubility test. Commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) materials, including resin composite (CERASMART), silicate-based PICN (ENAMIC), and zirconia ceramic (e.max ZirCAD), were used for comparison. The analyses highlight the dual network structure of EXP, which comprised a zirconia skeleton and an infiltrated resin phase. EXP exhibits a flexural strength of 346.0 ± 46.0 MPa, flexural modulus of 44.0 ± 3.7 GPa, and Vickers hardness of 440.1 ± 51.2 VHN. The mechanical properties of EXP are significantly higher than those of CERASMART and ENAMIC but lower than those of ZirCAD. Notably, the EXP hardness closely mimics that of the human enamel. The wear volume, SBS, and water sorption/solubility of EXP are comparable to those of CERASMART and ENAMIC. Therefore, EXP has potential applications as a tooth restorative material.
Topics: Humans; Materials Testing; Polymers; Composite Resins; Ceramics; Computer-Aided Design; Water; Surface Properties; Dental Porcelain; Dental Materials
PubMed: 38134584
DOI: 10.1016/j.jmbbm.2023.106320 -
Current Pharmaceutical Design 2016Energy intensive and chemical routes predominately govern modern dental material fabrication involving complex physicochemical approaches. Current interest in dental... (Review)
Review
Energy intensive and chemical routes predominately govern modern dental material fabrication involving complex physicochemical approaches. Current interest in dental material design is shifting towards biomineralization method and green chemistry synthesis to support oral tissue biocompatibility and oropharmacology. This review article describes the context of biophysical approaches based on development in nanoengineering to design advance nanomaterials for clinical dentistry. We particularly focus on approaches governing surface texture and hierarchical assembly emphasis based on micro-nanoscale tooth anatomy. Further, this article provides an overview about the merit of micro-nanoscale material design techniques exchanging the traditional dental material. In this context, top-down and bottom-up approaches involving biomimetic nanoengineering route, opportunities and challenges are discussed.
Topics: Biomimetics; Dental Materials; Dentistry; Humans; Nanostructures; Nanotechnology
PubMed: 26675228
DOI: 10.2174/1381612822666151210124001 -
Journal of Investigative and Clinical... Feb 2013In the past few decades, there has been an increase in demand for safety evaluation and control of dental materials used daily in dentistry; however, this task is... (Review)
Review
In the past few decades, there has been an increase in demand for safety evaluation and control of dental materials used daily in dentistry; however, this task is difficult and cumbersome. Dental materials that are passive and do not react with the oral environment will be more stable and have superior durability. It is expected that dental materials will be universally accepted and will not cause harm or injury to the surrounding structures in the oral cavity. This is an entirely negative approach to the material tolerance and biocompatibility, and hides the possibility that some positive gains can be achieved. Side-effects of dental materials are believed to be rare, and generally, those that have been reported are mild. There are wide varieties of materials used in dentistry, which include liners, irrigants, intracanal filling materials, intracanal medicaments, prosthetic materials, restorative materials, subgingival implants, and mouth rinses. Therefore, in this study, the biocompatibility of various commonly-used clinical materials used in contemporary dentistry was discussed.
Topics: Biocompatible Materials; Composite Resins; Dental Alloys; Dental Cements; Dental Materials; Dental Restoration, Permanent; Humans; Root Canal Irrigants; Safety
PubMed: 23255468
DOI: 10.1111/j.2041-1626.2012.00140.x -
Dental Clinics of North America Oct 2020Material selection is one of the most important decisions to be made by clinicians. Proper material selection can affect the long-term function, longevity, and esthetics... (Review)
Review
Material selection is one of the most important decisions to be made by clinicians. Proper material selection can affect the long-term function, longevity, and esthetics of restorations. There are a large number of restorative materials available, which has increased the complexity of the decision-making process. Improper material selection can lead to failures in the outcome. This article is designed to provide the practitioner with up-to-date practical information on ceramic restorative materials and techniques in a clear, evidence-based, and unbiased manner. It also provides decision-making guides to help the practitioner determine the best ceramic material for various clinical scenarios.
Topics: Ceramics; Dental Materials; Dental Porcelain; Esthetics, Dental; Humans
PubMed: 32888512
DOI: 10.1016/j.cden.2020.05.002 -
Dental Materials : Official Publication... Jul 2016This study simulated the shelf life to evaluate the stability of initiation systems on acidic photopolymerizable dental material, through an experimental self-adhering...
OBJECTIVES
This study simulated the shelf life to evaluate the stability of initiation systems on acidic photopolymerizable dental material, through an experimental self-adhering flowable composite resin (SACR).
METHODS
An SACR model was formulated with monomers Bis-GMA, TEGDMA, acidic monomer (GDMA-P), and inorganic fillers. Initiation system combinations of camphorquinone (CQ), tertiary amine (EDAB), diphenyl phosphine oxide (TPO), phenylbis phosphine oxide (BAPO), and the diphenyliodonium hexafluorophosphate (DPIHFP) were tested. Five SACRs were evaluated, varying the initiation system: SACRCQ, SACRCQ+EDAB, SACRCQ+EDAB+DPIHFP, SACRBAPO and SACRTPO. The SARC were stored at 23°C and, according to shelf life, were evaluated for degree of conversion (DC), polymerization rate (Rp) and microtensile bond strength (μTBS). The DC was evaluated after 0, 1, 2, 4, 8, 12, 24 and 48 storage weeks of SACRs. Bonding to dentin was performed after 0, 4, 8, 12 and 24 storage weeks of SACRs and tested immediately (24h) and after 6 and 12 months by μTBS. Halogen light curing unit (3M ESPE) was used for photoactivation procedures.
RESULTS
SACRCQ+EDAB+DPIHFP showed higher Rp. The DC of SACRCQ+EDAB, SACRCQ+EDAB+DPIHFP, and SACRBAPO were similar (40%) and higher than SACRTPO and SACRCQ (20 and 10%, respectively), staying stable up to 48 weeks. The SACRCQ, SACRCQ+EDAB, and SACRTPO had pre-testing failure on μTBS. The shelf life of SACRs did not affect the μTBS of the groups that obtained adhesion. Furthermore, the immediate μTBS (MPa) SACRCQ+EDAB+DPIHFP (8.4) was similar to SACRBAPO (10.5); however, after 12 months, only SACRCQ+EDAB+DPIHFP maintained the μTBS.
SIGNIFICANCE
The choice of a suitable initiation system is crucial to the performance and stability of acidic photopolymerizable dental material.
Topics: Bisphenol A-Glycidyl Methacrylate; Composite Resins; Curing Lights, Dental; Dental Bonding; Dental Materials; Dentin; Humans; Materials Testing; Polymerization; Resin Cements; Tensile Strength
PubMed: 27063461
DOI: 10.1016/j.dental.2016.03.016 -
Dental Materials Journal Jun 2019This review focusses on tribological aspects of teeth during function, the clinical significance of wear, wear of natural teeth and restorative materials and laboratory... (Review)
Review
This review focusses on tribological aspects of teeth during function, the clinical significance of wear, wear of natural teeth and restorative materials and laboratory methods to simulate wear of restorative materials. Ceramic, metal alloy and amalgam show low material wear, whereas resin-based materials demonstrate substantial wear in the long term. The clinical wear shows a high variability with the patient factor accounts for about 50% of the variability. Wear as such seldomly compromises the function of the stomatognath system or individual teeth and is in most cases an esthetic problem. Particles that are ingested due to attrition and abrasion wear may pose a health risk to the patient, especially those from composite resin materials. However, systematic clinical studies on that issue are not available. For laboratory research many wear simulation devices and methods have been developed but only few are validated and have a moderate correlation with clinical wear.
Topics: Composite Resins; Dental Materials; Dental Porcelain; Dental Restoration Wear; Esthetics, Dental; Humans; Materials Testing; Surface Properties
PubMed: 30918233
DOI: 10.4012/dmj.2018-140