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The Journal of Prosthetic Dentistry Dec 2022Making conventional facial impressions can be uncomfortable for the patient and complicated for the prosthodontist. Using facial scanners to digitize faces is an...
STATEMENT OF PROBLEM
Making conventional facial impressions can be uncomfortable for the patient and complicated for the prosthodontist. Using facial scanners to digitize faces is an alternative approach. However, the initial costs of the equipment have prevented their widespread use in dental practice, and the accuracy of ear scanning is unclear.
PURPOSE
The purpose of this in vitro study was to investigate the accuracy of a widely used intraoral scanner for digitizing an ear model.
MATERIAL AND METHODS
For reference, a silicone model of an ear was scanned with an industrial scanner. Then, the model was scanned 5 times with an intraoral scanner. Five conventional impressions of the model were made with a hydrocolloid impression material and poured with dental stone. The stone casts were then digitized with a desktop scanner. The data sets acquired with the 3 approaches were analyzed by using a 3-dimensional (3D) evaluation software program. Trueness and precision values were calculated for each approach. Linear mixed models with random intercepts were fitted to each sample to evaluate the effects of the impression method on mean deviations (α=.05).
RESULTS
Mean ±standard deviation trueness and precision values were 0.097 ±0.012 mm and 0.033 ±0.015 mm, respectively, for the digital scan, and 0.092 ±0.022 mm and 0.081 ±0.024 mm for the conventional impression, showing a significantly lower deviation in precision for the digital approach (P<.001).
CONCLUSIONS
The feasibility of digitizing an ear efficiently by using the investigated intraoral scanner was demonstrated, and similar trueness and significantly better precision values were achieved than when using conventional impressions. These promising results suggest the need for clinical investigations.
PubMed: 36586814
DOI: 10.1016/j.prosdent.2022.11.010 -
Frontiers in Dentistry 2021Intraoral scanners have shown promising results when used as an adjunct or alternative to conventional impression techniques. This study compared the accuracy of...
Intraoral scanners have shown promising results when used as an adjunct or alternative to conventional impression techniques. This study compared the accuracy of digital impression taking using an intraoral scanner versus the conventional technique. In this in-vitro experimental study, a typodont molar tooth was prepared as the standard model and scanned by TRIOS intraoral scanner. Ten digital impressions were fabricated as such and intraoral scans were sent to the manufacturers. In the conventional method, using addition silicone impression material, a stone die was fabricated. Using a computer-aided design/computer-aided manufacturing scanner, the die was scanned, and the data were transferred to the software. After the fabrication of frameworks, the replica technique was used. The replicas' thickness (indicative of the gap between the framework and the model and the accuracy of impression taking) was 12 points. The data were analyzed using student's t-test. The mean thickness of replicas (gap between the internal surface of frameworks and the standard model) at the three points in the buccal, lingual, mesial, and distal sections in the digital impression technique was lower than that in the conventional technique (P<0.0001). In other words, the accuracy of impressions taken by the digital method was significantly higher than those taken by the conventional method. Intraoral digital scanner had significantly higher accuracy than the conventional method in all points. Thus, the digital method can be reliably used as an adjunct or alternative to the conventional method to increase the accuracy of impression taking.
PubMed: 35965710
DOI: 10.18502/fid.v18i6.5649 -
Journal of Biological Regulators and... 2021For dental impression of a prepared tooth, the goal is a void-free negative representation from which an accurate cast of a tooth and its surrounding tissue can be...
For dental impression of a prepared tooth, the goal is a void-free negative representation from which an accurate cast of a tooth and its surrounding tissue can be reproduced. This in-vitro study assessed and compared the reproduction accuracies of surface detail obtained with three different dental elastomeric impression materials: vinyl polysiloxane (VPS), vinyl polyether silicone (VPES), and polyether (PE). A stainless-steel model with two abutments was used, with impressions taken 10 times for each material, for 20 abutment impressions per group, using a two-phase, one-step technique (heavy body/light body). The impressions were removed and assessed for numbers of enclosed voids and open voids visible on the surface. The defect frequency was 95% for impressions with the VPS and VPES materials, and 30% for the PE material. No significant differences were seen for number of impressions with defects for VPS versus VPES. Significant differences were seen for VPS and VPES versus the PE material (P <.05). No significant differences were seen for the defect type distributions across these three impression materials. The PE impression material showed better accuracy for reproduction of surface detail of these dental impressions compared to the VPS and VPES impression materials.
Topics: Dental Impression Materials; Dental Impression Technique; Materials Testing; Models, Dental; Reproducibility of Results; Surface Properties
PubMed: 33435664
DOI: 10.23812/20-561-A -
BMC Oral Health Jul 2023Polyvinyl ether siloxane (PVES) possesses ideal characteristics for making precise and accurate dental impressions. PVES dimensional stability owes to its better... (Meta-Analysis)
Meta-Analysis
BACKGROUND AND OBJECTIVES
Polyvinyl ether siloxane (PVES) possesses ideal characteristics for making precise and accurate dental impressions. PVES dimensional stability owes to its better polymeric properties derived from its parent materials poly ethers and polyvinyl siloxanes. As recommended use of chemical disinfecting agents is getting more popular, there is a growing concern associated with the effect of disinfectants on PVES dimensional stability. This study was aimed to understand the PVES behavior when subjected to chemical disinfectants.
MATERIALS AND METHODOLOGY
The data was collected from research studies retrieved from Google Scholar, Scopus, and PubMed using MeSH terms of keywords "vinyl polyether siloxane AND Disinfection" or (Vinyl polyether siloxane OR polyvinyl siloxane ether OR PVES) AND (disinfectant OR disinfection)" without any restriction to publication date. The PRISMA (Preferred Reporting Items for Systemic Review and Meta-Analysis) directions were observed during the data collection, screening of studies, and meta-analysis. The primary data were retrieved, and batch exported from databases using Harzing's Publish or Perish software; primary analysis was performed in Microsoft Excel, while statistical analysis for effect size, two-tailed p-values, and heterogeneity among studies was performed using Meta Essentials. The effect size was calculated using Hedge's g values at the 95% confidence level using the random-effects model. Heterogeneity among studies was measured using the Cochrane Q and I.
RESULTS AND CONCLUSION
Dental impressions made from the PVES elastomeric impression materials showed no significant changes in dimensional stability. Immersion in the chemical disinfectant for 10 min was associated with clinically irrelevant changes in the dimensions of the PVES impressions. Disinfection with sodium hypochlorite was associated with clinically significant changes in dimensions, with a two-tailed p-value of 0.049. Disinfection with 2-2.5% glutaraldehyde solution was not associated with any significant dimensional variability.
Topics: Humans; Disinfectants; Disinfection; Ether; Ethers; Ethyl Ethers; Polyvinyls; Siloxanes
PubMed: 37430254
DOI: 10.1186/s12903-023-03168-8 -
The Journal of Prosthetic Dentistry Oct 2022The technology behind optical scanners has greatly improved recently, making their dental application advantageous. While their accuracy is now comparable with that of... (Meta-Analysis)
Meta-Analysis Review
Patient preference and clinical working time between digital scanning and conventional impression making for implant-supported prostheses: A systematic review and meta-analysis.
STATEMENT OF PROBLEM
The technology behind optical scanners has greatly improved recently, making their dental application advantageous. While their accuracy is now comparable with that of conventional impression materials, whether these techniques have other advantages is unclear.
PURPOSE
The purpose of this systematic review and meta-analysis was to determine whether digital scanning for implant-supported restorations is more time-efficient and convenient for the patient.
MATERIAL AND METHODS
The study was conducted on September 23, 2020 using 4 different databases (Medline, Cochrane, Web of Science, Scopus) searching for clinical studies that compared the time needed and/or patient perceptions between those who had undergone the digital scanning procedure and those who had undergone conventional impression making.
RESULTS
Twelve studies met the inclusion criteria for qualitative and quantitative analysis. Outcome variables were measured as standard mean differences (SMDs) by following a fixed-effects model or random-effects model (in the case of high heterogeneity). Digital scanning was more time-efficient and was preferred by patients for all 4 analyzed outcomes (comfort, anxiety, nausea, time perception).
CONCLUSIONS
Digital scanning was found to be more time-efficient and convenient than conventional impression making for implant-supported restorations. Additional randomized controlled trials are needed to confirm the findings of this review.
Topics: Humans; Dental Impression Technique; Computer-Aided Design; Patient Preference; Dental Implants; Dental Impression Materials
PubMed: 33678434
DOI: 10.1016/j.prosdent.2020.11.042 -
Minerva Stomatologica Apr 2020Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of... (Review)
Review
Alginic acid is a polysaccharide widely present in the cellular walls of brown algae. Alginate is widely used as a mold material in dentistry, in the production of prostheses and in the production of positives for small-scale casting. It is also used in the pharmaceutical, cosmetic and food industries for various uses. The purpose of our study is to assess whether the chemical and physical characteristics of water can influence the characteristics and performance of these materials. These impression materials are often marketed as a powder to be mixed with water, but water is not included during the purchase. We have considered different articles, but unfortunately the results that speak of this topic are few and contain little information. We have therefore carried out a review of the present literature on Pubmed and Embase search engine. The same product used by two people with two different waters will have different characteristics. The possibility of knowing these effects could allow for more performing materials and above all for identical and reproducible materials. In conclusions, the results indicate to follow the manufacturer's instructions, and eventually turn to the use of automatic devices.
Topics: Alginates; Dental Impression Materials; Materials Testing; Powders
PubMed: 32489090
DOI: 10.23736/S0026-4970.19.04293-6 -
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 -
Journal of Pharmacy & Bioallied Sciences Jul 2023The current study examined the accuracy of casts generated using direct impression processes with and without splints for multiple dental implants utilizing two...
A Comparative Study to Assess Accuracy of Casts Prepared using Direct Impression Technique with and without Splinting of Multiple Dental Implants Utilising Two Different Splinting and Impression Materials.
BACKGROUND
The current study examined the accuracy of casts generated using direct impression processes with and without splints for multiple dental implants utilizing two different splinting materials and impression materials.
MATERIALS AND METHODS
Dental replacement base intensity alleviating acrylic tar was used to create a reference model of a mandible with four inserts (Uniti, Equinox, D-3.7 mm, and L-13 mm) in the front. Polyether and polyvinyle siloxane impression materials were used to make impressions of the reference model utilizing direct non-splinted and splinted techniques.
RESULTS
Polyether impression material was found to produce more accurate impressions than polyvinyl siloxane, and impressions made using transfer copings splinted with pattern resins were found to be more accurate than those made using either unsplinted copings or copings splinted with light-cured wax resin.
CONCLUSIONS
All six impression techniques resulted in casts that were different from the reference model. Next, the polyether-splinted (SPR) technique is the nonsplinted technique employing polyether and polyvinyle siloxane imprint materials, and then, the splinted techniques using polyether and polyvinyle siloxane and produced the most accurate casts in comparison with the reference model.
PubMed: 37694030
DOI: 10.4103/jpbs.jpbs_271_23 -
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 -
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