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International Endodontic Journal Apr 2022Materials used for endodontics and with direct contact to tissues have a wide range of indications, from vital pulpal treatments to root filling materials and those used... (Review)
Review
Materials used for endodontics and with direct contact to tissues have a wide range of indications, from vital pulpal treatments to root filling materials and those used in endodontic surgery. In principle, interaction with dental materials may result in damage to tissues locally or systemically. Thus, a great variety of test methods are applied to evaluate a materials' potential risk of adverse biological effects to ensure their biocompatibility before commercialization. However, the results of biocompatibility evaluations are dependent on not only the tested materials but also the test methods due to the diversity of these effects and numerous variables involved. In addition, diverse biological effects require equally diverse assessments on a structured and planned approach. Such a structured assessment of the materials consists of four phases: general toxicity, local tissue irritation, pre-clinical tests and clinical evaluations. Various types of screening assays are available; it is imperative to understand their advantages and limitations to recognize their appropriateness and for an accurate interpretation of their results. Recent scientific advances are rapidly introducing new materials to endodontics including nanomaterials, gene therapy and tissue engineering biomaterials. These new modalities open a new era to restore and regenerate dental tissues; however, all these new technologies can also present new hazards to patients. Before any clinical usage, new materials must be proven to be safe and not hazardous to health. Certain international standards exist for safety evaluation of dental materials (ISO 10993 series, ISO 7405 and ISO 14155-1), but researchers often fail to follow these standards due to lack of access to standards, limitation of the guidelines and complexity of new experimental methods, which may cause technical errors. Moreover, many laboratories have developed their testing strategy for biocompatibility, which makes any comparison between findings more difficult. The purpose of this review was to discuss the concept of biocompatibility, structured test programmes and international standards for testing the biocompatibility of endodontic material biocompatibility. The text will further detail current test methods for evaluating the biocompatibility of endodontic materials, and their advantages and limitations.
Topics: Biocompatible Materials; Dental Materials; Endodontics; Humans; Models, Theoretical; Research Design; Root Canal Filling Materials
PubMed: 35124840
DOI: 10.1111/iej.13701 -
Dental Materials : Official Publication... Jan 2023Different types of direct-placement dental materials are used for the restoration of structure, function and aesthetics of teeth. The aim of this research investigation...
OBJECTIVES
Different types of direct-placement dental materials are used for the restoration of structure, function and aesthetics of teeth. The aim of this research investigation is to determine, through a comparative cradle-to-gate life cycle assessment, the environmental impacts of three direct-placement dental restorative materials (DRMs) and their associated packaging.
METHODS
Three direct-placement dental materials; dental amalgam, resin-based composite (RBC) and glass polyalkenoate cements (GIC) are assessed using primary data from a manufacturer (SDI Limited, Australia). The functional unit consisted of 'one dental restoration' of each restorative system under investigation: 1.14 g of dental amalgam; 0.25 g of RBC (plus the adhesive = 0.10 g); and 0.54 g of GIC. The system boundary per restoration included the raw materials and their associated packaging materials for each DRM together with the processing steps for both the materials and packaging. The environmental impacts were assessed using an Egalitarian approach under the ReCiPe method using Umberto software and the Ecoinvent database. Nine different impact categories were used to compare the environmental performance of these materials.
RESULTS
Dental amalgam had the highest impact across most of the categories, but RBC had the highest Global Warming Potential. The highest sources of the environmental impacts for each restorative material were: Amalgam, derived from material use; RBC, derived from energy use in processing material and packaging material; GIC, derived from material and energy use for packaging.
SIGNIFICANCE
Less intensive energy sources or more sustainable packaging materials can potentially reduce the impacts associated with RBC and GIC thus making them suitable alternatives to dental amalgam.
Topics: Animals; Dental Restoration, Permanent; Dental Amalgam; Dental Materials; Glass Ionomer Cements; Life Cycle Stages; Composite Resins
PubMed: 36428112
DOI: 10.1016/j.dental.2022.11.007 -
Dental Materials Journal Jan 2021The objective of this study was to analyze the viscous behavior during setting reaction of resin composite cements and how it is influenced by temperature. Viscous...
The objective of this study was to analyze the viscous behavior during setting reaction of resin composite cements and how it is influenced by temperature. Viscous properties during auto-polymerization at 23°C of three adhesive (Panavia V5 [PV5]; RelyX Ultimate [RUL]; Multilink Automix [MLA]) and three self-adhesive (Panavia SA plus [PSA]; RelyX Unicem 2 Automix [RUN]; Multilink SpeedCem [MSC]) resin composite cements were rheometrically measured. Changes in contact angle and temperature during auto-polymerization were evaluated for each cement at 23°C and 37°C. Rheological analysis and temperature measurements corresponded in terms of curve progression. The tested resin composite cements demonstrated strong variations in their viscous behavior during setting reaction. PV5 and PSA become less viscous at 37°C and then polymerize quickly. For RUL and RUN at 37°C, viscosity rises, and polymerization takes place quickly. MLA and MSC start with high viscosity, then MSC polymerizes very fast and MLA rather slowly.
Topics: Composite Resins; Dental Bonding; Dental Materials; Materials Testing; Resin Cements; Surface Properties; Viscosity
PubMed: 33028791
DOI: 10.4012/dmj.2019-313 -
Journal of Oral Science Jul 2022Recently in Japan, due to the increased prices of palladium and gold, cast titanium restorations have been included in the Japanese national health insurance system. The... (Review)
Review
Recently in Japan, due to the increased prices of palladium and gold, cast titanium restorations have been included in the Japanese national health insurance system. The purpose of this review was to survey the available literature on titanium bonding systems, focusing on the adhesive monomer in the luting agent in order to expand the application of resin-bonded fixed prostheses made of titanium or titanium alloys. It was found that adhesive monomers are effective for bonding to titanium, and provide results equal to the procedures of silanization and tribochemical silica coating. A primer or a luting agent, including 10-methacryloyloxydecyl dihydrogen phosphate (MDP), methacryloyloxyalkyl thiophosphate derivative (MEPS), 6-methacryloxyhexyl phosphonoacetate (6-MHPA), and 4-methacryloyloxyethl trimellitate anhydride (4-META) promotes bonding characteristics between titanium and the resin material.
Topics: Alloys; Dental Bonding; Dental Cements; Materials Testing; Methacrylates; Resin Cements; Surface Properties; Titanium
PubMed: 35584941
DOI: 10.2334/josnusd.22-0036 -
Brazilian Dental Journal Jun 2020The objective of this work was to evaluate the effects of in vitro and in situ biodegradation on the surface characteristics of two resin cements and a hybrid ceramic...
The objective of this work was to evaluate the effects of in vitro and in situ biodegradation on the surface characteristics of two resin cements and a hybrid ceramic system. One hundred and eighty specimens (4X1.5mm) of each material (Maxcem Elite, NX3 Nexus and Vita Enamic) were made and randomly distributed in twelve groups (n=15) according to the material and biodegradation method. The specimens were then submitted to the following challenges: storage in distilled water 37 ºC for 24 h or 7 days, storage for 7 days, at 37 ºC, in stimulated saliva or in situ. The in situ stage corresponded to the preparation of 15 intraoral palatal devices, used for 7 days. Each device presented 3 niches, where a sample of each materials was accommodated. Specimens from both saliva and in situ groups suffered a cariogenic challenge, corresponding to the application of a solution of 20% of sucrose, 10 times throughout each day. After each biodegradation method, the surface roughness (Ra), Vickers hardness (VHN) and scanning electron microscopy (SEM) analyzes were performed. The data collected were evaluated by Levene test, two-way ANOVA and Tukey`s test (α=5%). The in situ challenge promoted the greater biodegradation, regardless of the material. Regarding the materials, the Vita Enamic VHN was negatively affected by all biodegradation methods and the Nexus NX3 presented better performance than the self-adhesive cement tested. Therefore, within the conditions of this work, it was concluded that in situ biodegradation can affect negatively the surface characteristics of indirect restorative materials.
Topics: Ceramics; Dental Materials; Hardness; Materials Testing; Resin Cements; Surface Properties
PubMed: 32667515
DOI: 10.1590/0103-6440202002982 -
Journal of the American Dental... Dec 2022This narrative review addresses dental restorative materials with sustained antibacterial action, especially those containing quaternary ammonium compounds. Secondary... (Review)
Review
BACKGROUND
This narrative review addresses dental restorative materials with sustained antibacterial action, especially those containing quaternary ammonium compounds. Secondary caries occurs around restorations, causing further loss of mineral and breakdown of the restoration. Lesions adjacent to restorations account for more than 40% of needed restorations. Restorative materials with antibacterial properties will potentially solve this problem.
TYPES OF STUDIES REVIEWED
Several groups are researching composite restorative materials that incorporate antibacterial agents. These agents are mostly exhausted over time. Newer studies involve materials that incorporate antibacterial microparticles that remain active and do not leach out.
RESULTS
One such antibacterial agent, quaternary ammonium coupled with inorganic silica into minute particles (QASi), has been studied in the laboratory and in humans. QASi particles incorporated into dental materials retain their antibacterial action over time without leaching or loss of activity. A clinical in situ study in humans using dental composite containing QASi resulted in highly significantly less demineralization in the adjacent enamel than the control composite material.
CONCLUSIONS AND PRACTICAL IMPLICATIONS
Dental restorative materials that contain QASi have sustained antibacterial properties, have mechanical properties comparable to those of presently marketed materials, and have been cleared by the US Food and Drug Administration. Clinical studies have shown that composites incorporating QASi have the potential to markedly reduce the occurrence of caries around restorations. Because caries around restorations is a major problem, restorative materials with sustained antibacterial properties will have an important effect in reducing secondary caries around restorations.
Topics: Humans; Quaternary Ammonium Compounds; Composite Resins; Dental Caries; Anti-Bacterial Agents; Dental Enamel; Dental Materials; Dental Restoration, Permanent
PubMed: 36272816
DOI: 10.1016/j.adaj.2022.09.006 -
Microbiology Spectrum Jun 2022Streptococcus mutans is a representative biofilm-forming bacterium that causes dental caries through glucosyltransferase (GTF) activity. Glucans are synthesized from...
Streptococcus mutans is a representative biofilm-forming bacterium that causes dental caries through glucosyltransferase (GTF) activity. Glucans are synthesized from sucrose by GTFs and provide binding sites for S. mutans to adhere tightly to the tooth enamel. Therefore, if a novel compound that interferes with GTF function is developed, biofilm formation control in S. mutans would be possible. We discovered that raffinose, an oligosaccharide from natural products, strongly inhibited biofilm formation, GTF-related gene expression, and glucan production. Furthermore, biofilm inhibition on saliva-coated hydroxyapatite discs through the reduction of bacterial adhesion indicated the applicability of raffinose in oral health. These effects of raffinose appear to be due to its ability to modulate GTF activity in S. mutans. Hence, raffinose may be considered an antibiofilm agent for use as a substance for oral supplies and dental materials to prevent dental caries. Dental caries is the most prevalent infectious disease and is expensive to manage. Dental biofilms can be eliminated via mechanical treatment or inhibited using antibiotics. However, bacteria that are not entirely removed or are resistant to antibiotics can still form biofilms. In this study, we found that raffinose inhibited biofilm formation by S. mutans, a causative agent of dental caries, possibly through binding to GtfC. Our findings support the notion that biofilm inhibition by raffinose can be exerted by interference with GTF function, compensating for the shortcomings of existing commercialized antibiofilm methods. Furthermore, raffinose is an ingredient derived from natural products and can be safely utilized in humans; it has no smell and tastes sweet. Therefore, raffinose, which can control S. mutans biofilm formation, has been suggested as a substance for oral supplies and dental materials to prevent dental caries.
Topics: Anti-Bacterial Agents; Biofilms; Biological Products; Dental Caries; Dental Materials; Glucans; Glucosyltransferases; Humans; Raffinose; Streptococcus mutans
PubMed: 35575506
DOI: 10.1128/spectrum.02076-21 -
BMC Oral Health Feb 2021Tooth fractures can occur after temporary inter-appointment endodontic filling, resulting in not preserving and thus extraction of the affected tooth. The purpose of...
BACKGROUND
Tooth fractures can occur after temporary inter-appointment endodontic filling, resulting in not preserving and thus extraction of the affected tooth. The purpose of this investigation was therefore to evaluate the tooth substance fracture potential given by the expansion of endodontic temporary filling materials.
METHODS
Tooth and access cavities were prepared in 80 mandibular molars. Four groups of 20 teeth each (Cavit, Cavit W and Coltosol F and control) were included. To simulate a clinical situation, the teeth were endodontically pre-treated and a calcium hydroxide dressing was placed. The cavities were filled with the corresponding temporary filling material, with exception of the control group, and kept submerged in distilled water for 15 days. The teeth were examined every 24 h by two calibrated observers under a stereomicroscope (7.5×), fractures of the temporary filling material and tooth structure were photo-documented, and the results statistically analyzed. Kaplan-Meier survival analysis were calculated to illustrate (survival = no fracture) probabilities to evaluate the time when the temporary filling material, tooth structure or both together occurred. Log-rank test was performed in order to assess significant differences between the materials and the subgroups used.
RESULTS
Fractures were observed only in the Coltosol F group (p < 0.01), at the end of the observation period, a total of 13 teeth (65%) showed temporary filling material and eight teeth (40%) showed tooth structure fractures. No fractures in the pulp chamber area were observed at the end of the observation period in any group.
CONCLUSIONS
Within the limitations of the current in vitro study, the results obtained suggest that tooth structure fractures caused by a temporary filling material can occur during endodontic treatment, thus compromising the success of the treatment.
Topics: Calcium Sulfate; Dental Cements; Dental Restoration, Temporary; Humans; Polyvinyls; Root Canal Filling Materials; Tooth Fractures; Zinc Oxide; Zinc Sulfate
PubMed: 33593339
DOI: 10.1186/s12903-021-01431-4 -
British Dental Journal Nov 2021Sectional matrix techniques offer more predictable solutions to achieving contact areas when placing direct interproximal posterior composites than circumferential...
Sectional matrix techniques offer more predictable solutions to achieving contact areas when placing direct interproximal posterior composites than circumferential matrix techniques, resulting in reduced reported complaints of food packing from patients. Despite this, a large majority of UK dentists and therapists don't currently use them. Sectional matrix systems are technique-sensitive to use, which can be a barrier to implementation for inexperienced users. The matrices can easily distort during their placement and stabilisation and when placing the restorative material. This can result in unwanted, clinically relevant problems in the resulting restorations, some of which may not be discernible once they have occurred. This paper explores the advantages and disadvantages of sectional matrices and the processes and techniques involved in their use, before discussing the potential for distortion at each step. It offers solutions to some of the commonly seen problems which will provide more predictable outcomes for those already using these techniques and encourage non-users to add them to their armamentarium.
Topics: Composite Resins; Dental Cavity Preparation; Dental Materials; Dental Restoration, Permanent; Humans; Matrix Bands
PubMed: 34773017
DOI: 10.1038/s41415-021-3608-5 -
Swiss Dental Journal Feb 2022Over the last years, bioactive glass particles have been successfully incorporated in dental restorative materials. Remineralizing effects on dental hard tissue and...
Over the last years, bioactive glass particles have been successfully incorporated in dental restorative materials. Remineralizing effects on dental hard tissue and antibacterial properties are promising properties of these customized composites. A few materials doped with bioactive fillers are already available on the dental market. Nevertheless, further research is required to fine-tune bioactive composites for biomimetic restorative approaches.
Topics: Dental Materials; Dentistry
PubMed: 35107004
DOI: 10.61872/sdj-2022-02-03