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Materials (Basel, Switzerland) Nov 2022In the intraoral scanner (IOS) impression technique for dental implants, a scanbody (SB) is connected to the implant and scanned. Poly(ether-ether-ketone) (PEEK) is a...
In the intraoral scanner (IOS) impression technique for dental implants, a scanbody (SB) is connected to the implant and scanned. Poly(ether-ether-ketone) (PEEK) is a widely used material for SBs and it is recommended for single use. However, from the perspective of the Sustainable Development Goals, it is desirable to use these products multiple times. As SBs are used in patients' mouths, proper sterilization is necessary for multiple uses. In the present study, the effect of autoclave treatment and connection/disconnection on SB deformation was investigated. The SB was connected to the implant and stereolithography (STL) data were obtained. Then, the SB was disconnected and underwent autoclave treatment, or was connected and disconnected multiple times, or underwent a combination of both processes. The results showed that there were significant differences in the distance and angle when comparing SBs before and after the autoclave treatment, but repeated connections with or without autoclave treatment had no significant impact on the measured values. The surface texture, observed with scanning electron microscopy, showed that a groove was observed on the surface of the SB, but the groove did not show major changes after 10 connection/autoclave processes. These results indicate that autoclave sterilization has some impact on SB deformation but connection/disconnection itself may not have a huge impact on SB deformation.
PubMed: 36363311
DOI: 10.3390/ma15217717 -
The Saudi Dental Journal May 2020The objective of this systematic review and meta-analysis study was to identify the different disinfection methods and materials and the existing evidence on their... (Review)
Review
Effect of chemical, microwave irradiation, steam autoclave, ultraviolet light radiation, ozone and electrolyzed oxidizing water disinfection on properties of impression materials: A systematic review and meta-analysis study.
OBJECTIVES
The objective of this systematic review and meta-analysis study was to identify the different disinfection methods and materials and the existing evidence on their effect on properties of the different impression materials.
MATERIAL AND METHODS
An electronic search of MEDLINE (PubMed), Science Direct, and Google Scholar databases was performed to retrieve related English-language articles published between January 2000 and July 2019. Available studies with search terms such as: Impression disinfection, disinfection method, impression dimensional stability and impression wettability were used. The selected articles were reviewed by screening their titles and abstracts and full text. Finally, a total of 70 articles were considered relevant and were included in this study.
RESULTS
Extensive studies were conducted to determine the effect of the different disinfection methods and materials on the properties of the different impression materials such as dimensional stability, wettability and surface roughness. While some studies reported significant changes in the properties of the impression materials, others reported either no changes or minor insignificant effects.
CONCLUSIONS
Some studies reported significant changes in the properties of the impression materials as a result of using different disinfection methods, whereas others reported either minor insignificant or no changes. Although the findings of the studies were controversial, care should be taken to avoid distortion of impressions and loss of their surface details that can adversely affect the fitting accuracy of the restorations. Therefore, better designed and standardized studies are needed to evaluate the effect of different commonly used disinfectants on properties of impression materials. Moreover, manufacturers should be encouraged to recommend specific disinfection methods and materials for disinfecting the impression materials to ensure their optimal accuracy.
PubMed: 32405219
DOI: 10.1016/j.sdentj.2019.12.003 -
BMC Research Notes Jun 2022Since there is no material in the market met all the ideal requirements of an impression material, thus in an attempt to find one, hybridization between the two most...
OBJECTIVE
Since there is no material in the market met all the ideal requirements of an impression material, thus in an attempt to find one, hybridization between the two most commonly used impression materials were done. The aim of the hybridization was to obtain a new material combining the good merits of both and eliminate their shortcomings. Thus, this study aimed to assess the impact of hybridization between polyether with addition silicone on tear strength and elastic recovery of the new material and compare such effect with regard to parent materials.
RESULTS
A polyether (PE), polyvinyl siloxanse (PVS) and vinyl polyether silicone (VPES) hybrid elastomers were used in the present study. Tear strength was measured one hour after setting time of each material according to the manufacturer and the three materials showed statistically comparable tear strength in N/mm. Elastic recovery was evaluated one minute after the setting time recommended by the manufacturer. The three materials were statistically insignificant from each other, and all met the ISO4823 requirement of having greater than 96.5% recovery.
Topics: Dental Impression Materials; Elasticity; Materials Testing; Polyvinyls; Resins, Synthetic; Silicone Elastomers; Surface Properties
PubMed: 35761301
DOI: 10.1186/s13104-022-06110-3 -
BioMed Research International 2019Recent data indicates limited awareness and compliance on infection prevention procedures by dental offices and by dental laboratories. Guidelines for infection... (Review)
Review
Recent data indicates limited awareness and compliance on infection prevention procedures by dental offices and by dental laboratories. Guidelines for infection prevention in dentistry have been published by Centres for Disease Control and Prevention since 2003; the section "IX-Special consideration" includes a subsection concerning the prevention in dental laboratories, but it has not been modernised in later versions to fit the needs of traditional and computer-aided technology. Traditional techniques required disinfecting items (impression, chewing waxes, and appliances) with well-suited products, which are also chosen for limiting impression changes or appliance deterioration. Effective procedures are available with difficulties. Some of these contain irritant or non-eco-friendly disinfectants. The transport of impression, to dental laboratories, is often delayed with limited precautions for limiting cross-infection. Gypsum casts are frequently contaminated mainly by bacteria and their antibiotic-resistant strains and even stored for long periods during dental implant supported restoration and orthodontic therapy, becoming a hidden source of infection. Nowadays, computer-aided design/computer-aided manufacturing technology seems to be an interesting way to promote both business and safety, being more comfortable for patients and more accurate than traditional technology. A further advantage is easier infection prevention since, for the most part, mainly digital impression and casts are not a source of cross-infection and the transport of contaminated items is reduced and limited to try-in stages. Nevertheless, a peculiar feature is that a digital electronic file is of course unalterable, but may be ruined by a computer virus. Additionally, the reconditioning of scanner tips is determinant for the optical characteristics and long term use of the scanner, but information for its reconditioning from producers is often limited. This study focuses on some critical points including (a) insufficient guidelines, (b) choice of proper procedure for scanner reconditioning, and (c) data protection in relation to patient privacy.
Topics: Computer-Aided Design; Dental Implants; Dental Impression Materials; Dental Impression Technique; Dentistry; Humans; Infections
PubMed: 31467901
DOI: 10.1155/2019/6092018 -
Journal of Dental Sciences Apr 2023An understanding of self-protection related factors is important for dental infection control. This study aimed to investigate factors associated with personal...
BACKGROUND/PURPOSE
An understanding of self-protection related factors is important for dental infection control. This study aimed to investigate factors associated with personal self-protection in infection control among dental care workers.
MATERIALS AND METHODS
A cross-sectional survey with self-report questionnaire was conducted between Jan and Dec, 2018.275 dentists and 298 dental assistants were enrolled from randomly selected dental care settings.
RESULTS
Compliance with wearing hair caps, facial masks, and hand washing is not as high as oral masks and gloves (over 90%). For dentists, the level of clinical setting (aOR = 3.1, < 0.001) and the correct use of disinfectants for impression materials (aOR = 2.0, < 0.05) were associated with hair cap wearing. Gender (aOR = 0.15, < 0.05) and correct use of indicator during sterilization (aOR = 2.9, < 0.05) were associated with facial mask wearing. The correct use of indicator during sterilization (aOR = 2.4, < 0.05) and disinfection for impression materials (aOR = 2.2, < 0.05) were associated with hand washing. For dental assistants, longer work experience (aOR = 1.05, < 0.05), working days (aOR = 1.82, < 0.05), the correct use of disinfectants for impression materials (aOR = 2.4, < 0.001), and the frequent use of gloves (aOR = 8.0, < 0.05) were associated with facial mask wearing. The surface disinfection of working tables (aOR = 2.8, < 0.001) and the frequent changing of gloves (aOR = 5.96, < 0.05) were associated with hand washing.
CONCLUSION
Gender, the length of work practice, and correct techniques for sterilization use were identified as major factors associated with compliance with self-protection in infection control among dental care workers.
PubMed: 37021205
DOI: 10.1016/j.jds.2022.11.023 -
Biomaterials Research Dec 2020The era of Nanomaterials has had a long lasting impression in the field of medical science. It's excellent use in medicine has led to its application in dental science.... (Review)
Review
BACKGROUND
The era of Nanomaterials has had a long lasting impression in the field of medical science. It's excellent use in medicine has led to its application in dental science. Serious concerns regarding the eradication of microbial biofilms from the root canal system still exists in the field of endodontics. Nanoparticles have proven to be much more efficient with good bonding capabilities and surface chemistry as compared to the conventional materials. The practical applications of nanotechnology in endodontics has led to future prospects in research in this field.
MAIN BODY
Nanoparticles in endodontics have shown promising results. The various nanoaprticles like graphene, silver nanoparticles, chitosan, hydroxyapaptite nanoparticles, Iron compound, zirconia, Poly (lactic) co-glycolic acid, bioactive glass, mesoporous calcium silicate, titanium dioxide nanoparticles, Magnesium, Calcium oxide and Copper oxide have been discussed. These nanoparticles have fetched and shown great results in various application in endodontics like incorporation of nanoparticles in selaers, obturating materials, irrigation, and intracanal medicament.
CONCLUSION
The application of nanoparticles from natural and synthetic materials is rapidly evolving in dentistry. These biomaterials have helped in treatment of oral diseases, in eradication of smear layer and biofilms, have been incorporated in various dental materials for their antimicrobial effects. Combining all their beneficial aspects, these nanoparticles will provide new paradigm shift in dentistry. This review on nanoparticles will provide the reader with the latest knowledge of these materials, their mechanism of action and its implications in endodontics.
PubMed: 33292702
DOI: 10.1186/s40824-020-00198-z -
Clinical Oral Investigations Mar 2021To evaluate the dimensional accuracy of impressions taken by use of disposable stock plastic trays and to compare performance with that of metal trays.
OBJECTIVES
To evaluate the dimensional accuracy of impressions taken by use of disposable stock plastic trays and to compare performance with that of metal trays.
MATERIALS AND METHODS
From a metallic model incorporating three precision balls and three abutment teeth, one-step dual-phase polyether (PE) and vinyl polysiloxane (VPS) impressions were taken using either metal or disposable plastic trays (n = 10 for each of the resulting four test groups). Respective plaster cast scans were aligned with the reference dataset to evaluate global (distance and angle deviations) and local (trueness and precision) accuracy. Analyses of variance (ANOVA) were conducted to determine group differences.
RESULTS
For all impression tray and material combinations, global accuracy was good (mean distance changes < 100 μm) with greatest deviations being observed for distances exceeding one quadrant of the dental arch. In general, distances measured in the plaster casts were too short. Only VPS impressions with plastic trays showed a different behavior with a large percentage of cross-arch distances exceeding the reference value. Mean local accuracy ranged between 6 and 14 μm (trueness), and 6 and 16 μm (precision). On abutment tooth level, metal trays were associated with a significantly better precision (p = 0.015).
CONCLUSIONS
The observed distortions of the studied impression trays and materials are small and should enable satisfying clinical impression-taking.
CLINICAL RELEVANCE
Cleaning and processing of metal trays before re-use are time-consuming. Especially for patients' management with single crowns and small fixed dental prostheses, disposable plastic trays can be a viable and cost-effective alternative.
Topics: Dental Impression Materials; Dental Impression Technique; Humans; Models, Dental; Plastics; Polyvinyls; Siloxanes
PubMed: 32885321
DOI: 10.1007/s00784-020-03455-6 -
Journal of Oral Rehabilitation Jun 2019The aims of this study were to test the hypotheses that (a) a laserscanner used for measuring maximum depth and volume loss will yield the same results as a surface...
OBJECTIVES
The aims of this study were to test the hypotheses that (a) a laserscanner used for measuring maximum depth and volume loss will yield the same results as a surface profilometer; (b) the surface roughness will affect the maximum depth and volume loss measured with the laserscanner; (c) analytical results using the laserscanner from multiple operators have no more than 10% inter-rater difference and; (d) replicating samples using either stone or impression material is an accurate method for measuring wear using the laserscanner.
MATERIALS AND METHODS
The volume and maximum depth of indentations from fine, medium and rough burs on glass-ceramic disks were measured using two devices, a surface profilometer (Dektak II, Veeco) and a 3D Laserscanner (LAS-20, SD Mechatronik). Replicates of the indentations made from polyvinysiloxane impression material and gypsum were also measured.
RESULTS
Comparison of profilometer and laserscanner readings using ceramic disks demonstrated a mean error of 13.61% for depth and 25.32% for volume. Replication errors were minimal (2.6% for impression, 2.5% for stone). Surface profilometer data for volume measurements revealed a difference of 6.1% for impression and 6.5% for stone compared with ceramics. However, when measurements for replicates were compared between laserscanner and surface profilometer, depth had a mean error of 74% for impression and 51% for stone. Volume differences of 78% for impression and 44% for stone were recorded.
CONCLUSION
This work demonstrated that the laserscanner was a convenient device for measuring wear but there is a need to validate the accuracy of the measurements.
Topics: Ceramics; Dental Impression Materials; Materials Testing; Surface Properties
PubMed: 30759313
DOI: 10.1111/joor.12778 -
Gels (Basel, Switzerland) May 2023Impression materials could be a source of cross-contamination due to the presence of microorganisms from blood and saliva inside the oral cavity. Nevertheless, routinely...
OBJECTIVES
Impression materials could be a source of cross-contamination due to the presence of microorganisms from blood and saliva inside the oral cavity. Nevertheless, routinely performed post-setting disinfection could compromise the dimensional accuracy and other mechanical properties of alginates. Thus, this study aimed to evaluate detail reproduction, dimensional accuracy, tear strength, and elastic recovery of new experimentally prepared self-disinfecting dental alginates.
METHODS
Two antimicrobial-modified dental alginate groups were prepared by mixing alginate powder with 0.2% silver nitrate (AgNO group) and a 0.2% chlorohexidine solution (CHX group) instead of pure water. Moreover, a third modified group was examined by the extraction of () oleoresin using water. The extract was used to reduce silver nitrate to form silver nanoparticles (AgNPs), and the mixture was used as well in dental alginate preparation ( + AgNP group). Dimensional accuracy and detail reproduction were examined as per the ISO 1563 standard guidelines. Specimens were prepared using a metallic mold engraved with three parallel vertical lines 20, 50, and 75 µm wide. Detail reproduction was evaluated by checking the reproducibility of the 50 µm line using a light microscope. Dimensional accuracy was assessed by measuring the change in length between defined reference points. Elastic recovery was measured according to ISO 1563:1990, in which specimens were gradually loaded and then the load was released to allow for recovery from the deformation. Tear strength was evaluated using a material testing machine until failure at a crosshead speed of 500 mm/min.
RESULTS
The recorded dimensional changes between all tested groups were insignificantly different and within the reported acceptable values (between 0.037-0.067 mm). For tear strength, there were statistically significant differences between all tested groups. Groups modified with CHX (1.17 ± 0.26 N/mm) and + AgNPs (1.11 ± 0.24 N/mm) showed higher tear strength values compared to the control (0.86 ± 0.23 N/mm) but were insignificant from AgNO (0.94 ± 0.17 N/mm). All tested groups showed elastic recovery values that met both the ISO standard and ADA specifications for elastic impression materials and tear strength values within the acceptable documented ranges.
DISCUSSION
The CHX, silver nitrate, and green-synthesized silver nanoparticles could be promising, inexpensive alternatives for the preparation of a self-disinfecting alginate impression material without affecting its performance. Green synthesis of metal nanoparticles could be a very safe, efficient, and nontoxic method, with the advantage of having a synergistic effect between metal ions and active chemical constituents of plant extracts.
PubMed: 37233020
DOI: 10.3390/gels9050429 -
Clinical Oral Investigations Jun 2023The aim of this study was to evaluate the accuracy, in terms of trueness and precision, of printed models using five different industrial and dental desktop 3D printers.
OBJECTIVES
The aim of this study was to evaluate the accuracy, in terms of trueness and precision, of printed models using five different industrial and dental desktop 3D printers.
MATERIALS AND METHODS
Full-arch digital models with scanbodies of 15 patients were printed with five different 3D printers. The industrial printers were 3D system Project MJP2500 (3DS) and Objet30 OrthoDesk (Obj). The dental desktop printers were NextDent 5100 (ND), Formlabs Form 2 (FL) and Rapidshape D30 (RS). A total of 225 printed models were analysed. The printed models were digitized and compared with the reference cast model using the Control X software (Geomagic). The descriptive statistics and one-way ANOVA with the post hoc Tukey test were performed (α = 0.05).
RESULTS
The one-way ANOVA for the trueness and precision of the printed model presented the best results for the 3DS, followed by ND, Obj, FL and RS (P < 0.01). In the scanbody zone, the best results were for the 3DS group, followed by Obj, ND, FL and RS (P < 0.01). Comparing the technologies, the Multijet technology used in industrial printers presented better results than the DLP and SLA technologies used in dental desktop printers (P > 0.01).
CONCLUSIONS
There were statistically significant differences in terms of the accuracy of the printed models, with better results for the industrial than the dental desktop 3D printers.
CLINICAL RELEVANCE
The industrial 3D printers used in dental laboratories presented better accuracy than the in-office dental desktop 3D printers, and this should be considered when the best accuracy is needed to perform final prosthetic restorations.
Topics: Humans; Models, Dental; Workflow; Printing, Three-Dimensional; Software; Computer-Aided Design
PubMed: 36462040
DOI: 10.1007/s00784-022-04809-y