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Journal of Dentistry Dec 2022To assess time efficiency and the efficacy of the prosthetic manufacturing for implant crown fabrication in a centralized workflow applying computer aided design and... (Randomized Controlled Trial)
Randomized Controlled Trial
Time efficiency and efficacy of a centralized computer-aided-design/computer-aided-manufacturing workflow for implant crown fabrication: A prospective controlled clinical study.
OBJECTIVE
To assess time efficiency and the efficacy of the prosthetic manufacturing for implant crown fabrication in a centralized workflow applying computer aided design and computer aided manufacturing (CAD-CAM).
MATERIAL AND METHODS
Fifty-nine patients with one posterior implant each, were randomly allocated to either a centralized digital workflow (c-DW, test) or a laboratory digital workflow (l-DW, control). Patients were excluded from efficiency and efficacy analyses, if any additional restoration than this single implant crown had to be fabricated. A customized titanium abutment and a monolithic zirconia crown were fabricated in the c-DW. In the l-DW, models were digitalized for CAD-CAM fabrication of a monolithic zirconia crown using a standardized titanium base abutment. Time for impression, laboratory operating and delivery time were recorded. The efficacy of the prosthetic manufacturing was evaluated at try-in and at delivery. Data was analyzed descriptively. Statistical analyses using student's unpaired t- and paired Wilcoxon were performed (p < 0.05).
RESULTS
At impression taking, 12 patients (c-DW) and 19 patients (l-DW) were included. The impression time was 9.4±3.5 min (c-DW) and 15.1 ± 4.6 min (l-DW) (p < 0.05). The laboratory operating time was 130 ± 31 min (c-DW) and 218.0±8 min (l-DW) (p < 0.05). The delivery time was significantly longer in the c-DW (5.9 ± 3.5 1 days) as compared to the l-DW (0.5±0.05 days). At try-in and at delivery, efficacy of prosthetic manufacturing was similar high in both workflows.
CLINICAL RELEVANCE
The c-DW was more time efficient compared to the lab-DW and rendered a similar efficacy of prosthetic manufacturing.
Topics: Humans; Workflow; Prospective Studies; Titanium; Crowns; Zirconium; Computer-Aided Design; Computers; Dental Prosthesis Design
PubMed: 36252858
DOI: 10.1016/j.jdent.2022.104332 -
The International Journal of... 2016The aim of this study was to assess the antimicrobial activity of chemical disinfectants on alginate and silicone impression materials. The effect of chemical... (Comparative Study)
Comparative Study
PURPOSE
The aim of this study was to assess the antimicrobial activity of chemical disinfectants on alginate and silicone impression materials. The effect of chemical disinfectants on the dimensional stability of the impression materials was also assessed.
MATERIALS AND METHODS
For the microbiologic assessment, impressions of the maxillary arch were taken from 14 participants, 7 using alginate and 7 using an addition silicone. The impressions were divided into three sections. Each section was subjected to spraying with MD 520 or Minuten or no disinfection (control), respectively. Antimicrobial action of the chemical disinfectants was assessed by measuring microbial counts in trypticase soy agar (TSA) media and expressing the results in colony-forming units/cm2. The surface area of the dental impressions was calculated by scanning a stone cast using computer-aided design/computer-assisted manufacture and analyzing the data using a custom computer program. The dimensional stability of the impression materials after immersion in disinfectants was assessed by measuring the linear displacement of horizontally restrained materials using a traveling microscope. The percent change in length over 3 hours was thus determined.
RESULTS
Alginate exhibited a higher microbial count than silicone. MD 520 eliminated all microbes as opposed to Minuten. The bacterial growth after Minuten disinfection was almost twice as much for alginate than for addition silicone impressions. The chemical disinfectants affected the alginate dimensional stability. Minuten reduced the shrinkage sustained by alginate during the first hour of storage.
CONCLUSIONS
Alginate harbors three times more microorganisms than silicone impression material. Chemical disinfection by glutaraldehyde-based disinfectant was effective in eliminating all microbial forms for both alginate and silicone without modifying the dimensional stability. Alcohol-based disinfectants, however, reduced the alginate shrinkage during the first 90 minutes of setting. The current studies also propose another method to report the surface area based on accurate estimation by 3D image analysis.
Topics: Adult; Alginates; Anti-Infective Agents; Bacteria; Bacterial Load; Computer-Aided Design; Dental Disinfectants; Dental Impression Materials; Dental Impression Technique; Ethanol; Glutaral; Humans; Imaging, Three-Dimensional; Materials Testing; Maxilla; Polyvinyls; Siloxanes; Surface Properties; Time Factors; Young Adult
PubMed: 26757331
DOI: 10.11607/ijp.4358 -
Cureus Feb 2024Background The disinfection of dental impression materials is a cornerstone of infection control in dental practice. This study aimed to evaluate the effectiveness of...
Background The disinfection of dental impression materials is a cornerstone of infection control in dental practice. This study aimed to evaluate the effectiveness of two disinfectants, sodium hypochlorite and iodophor, on alginate and silicone impression materials, which are prone to microbial contamination. Methods The study was structured into two main groups based on the impression material: Group I (alginate) and Group II (addition silicone), each further subdivided into two subgroups for disinfection with sodium hypochlorite and iodophor. For each subgroup, initial microbial swabs were taken before any treatment, followed by a second swab after rinsing and a final swab after disinfection. The mean colony-forming unit (CFU) counts, standard deviations, and standard errors of the mean were calculated for each stage of treatment. Results Prior to disinfection, Group I had a mean CFU count of 2,529.40, while Group II had a lower mean CFU of 1,417.40. After rinsing, there was a significant decrease in CFUs in both groups, with Group I at 1,337.10 and Group II at 415.10. Post-disinfection, Group I showed a mean CFU count of 73.00 for sodium hypochlorite and 0.00 for iodophor. Similarly, Group II achieved a CFU reduction of 99.00 with sodium hypochlorite and 0.00 with iodophor, demonstrating a marked reduction in microbial presence. Conclusion Iodophor was exceptionally effective in disinfecting both alginate and silicone impression materials, eliminating all detectable CFUs. Sodium hypochlorite also significantly reduced microbial counts but was not as effective as iodophor. Rinsing prior to disinfection was instrumental in reducing the microbial load, underscoring its importance in the disinfection protocol.
PubMed: 38533142
DOI: 10.7759/cureus.54846 -
The Journal of Prosthetic Dentistry May 2020The definitive impression for a single-unit crown involves many material and technique factors that may affect the success of the crown.
Clinical acceptance of single-unit crowns and its association with impression and tissue displacement techniques: Findings from the National Dental Practice-Based Research Network.
STATEMENT OF PROBLEM
The definitive impression for a single-unit crown involves many material and technique factors that may affect the success of the crown.
PURPOSE
The purpose of this prospective cohort study was to determine whether impression technique (tray selection), impression material, or tissue displacement technique are associated with the clinical acceptability of the crown (CAC).
MATERIAL AND METHODS
Dentists in the National Dental Practice-Based Research Network documented details of the preparation, impression, and delivery of 3730 consecutive single-unit crowns. Mixed-effects logistic regression analyses were performed to evaluate associations between impression techniques and materials and the CAC and to assess associations between the presence of a subgingival margin with the displacement technique and the outcome variables CAC and number of impressions required.
RESULTS
Of the 3730 crowns, 3589 (96.2%) were deemed clinically acceptable. A significant difference in the CAC was found with different impression techniques (P<.001) and different impression materials (P<.001). The percentage of the CAC for digital scans was 99.5%, 95.8% for dual-arch trays, 95.2% for quadrant trays, and 94.0% for complete-arch impression trays. Although no statistically significant difference was found in the CAC produced with dual-arch trays without both mesial and distal contacts, crowns fabricated under these conditions were less likely to achieve excellent occlusion. The percentage of the CAC for digital scans was 99.5%, 97.0% for polyether impressions, 95.5% for polyvinyl siloxane impressions, and 90.5% for other impression materials. Accounting for the location of the margin, the use of a dual-cord displacement technique was significantly associated with lower rates of requiring more than 1 impression (P=.015, odds ratio=1.43).
CONCLUSIONS
Dual-arch trays produced clinically acceptable crowns; however, if the prepared tooth was unbounded, the occlusal fit was more likely to have been compromised. Digital scans produced a slightly higher rate of CAC than conventional impression materials. The use of a dual-cord technique was associated with a decreased need to remake impressions when the margins were subgingival.
Topics: Crowns; Dental Impression Materials; Dental Impression Technique; Models, Dental; Prospective Studies; Tooth
PubMed: 31590974
DOI: 10.1016/j.prosdent.2019.05.016 -
Australian Dental Journal Dec 1999
Topics: Colloids; Dental Impression Materials; Elastomers; Humans; Polyvinyls; Surface Properties; Water; Wettability
PubMed: 10687241
DOI: No ID Found -
Journal of International Society of... 2018The present study is conducted to explore the knowledge, attitude, and practice towards impression technique and materials for recording impression in implant placement...
OBJECTIVES
The present study is conducted to explore the knowledge, attitude, and practice towards impression technique and materials for recording impression in implant placement among general dental practitioners.
MATERIALS AND METHODS
The present study is a cross-sectional questionnaire study. The study was conducted among general dental practitioners in Patna city in November-December 2017. Patna city was divided into five directions, which are north, south, east, west, and central. From each direction, 20 clinics were selected randomly, and dental practitioners from there clinics were interviewed. A closed-ended questionnaire consists of 19 items was prepared, the questionnaire was divided into four parts.
RESULTS
Majority of study participants (58 [34%]) were above the age of 40 years. 96 (56%) of study participants were male. Most of the study participants (89 [50%]) were having MDS degree. Knowledge, attitude, and behavior scores among study participants. About 43% of study participants have good knowledge scores regarding impression technique and material in implant placement while 50% of study participants had fair attitude score. About 58% of study participants had fair practice score. There was statistically significant correlation ( ≤ 0.05*) between knowledge and attitude of study participants.
CONCLUSION
It was concluded that there was good knowledge, fair attitude, and practice among the dental professionals regarding the impression technique and materials for recording impression in implant placement. There was statistically significant correlation between knowledge and attitude of study participants. There was statistically significant correlation between some demographic variables and knowledge, attitude, and practice of study participants.
PubMed: 30430076
DOI: 10.4103/jispcd.JISPCD_325_18 -
Journal of Family Medicine and Primary... Jan 2021Among the several materials and techniques being used in fixed prosthodontics, impression materials and techniques were the major focus of this study. These materials...
INTRODUCTION
Among the several materials and techniques being used in fixed prosthodontics, impression materials and techniques were the major focus of this study. These materials are available in the market to be used by dental practitioners. However, their choice depends on certain factors, which include their properties, advantages, disadvantages, and cost.
MATERIALS AND METHODS
A questionnaire-based cross-sectional study was conducted among dental students using online survey. Dental students from Riyadh city willing to take part in this study were requested to fill up and submit the survey questionnaire.
RESULTS
Six hundred and sixteen out of 800 dental students from Riyadh city took part in this study. It was noted from the findings that 88% male students used alginate for diagnostic impressions, which was statistically significant and lower than females (94%). Ninety-one percent of the interns reported that they used retraction cord for gingival retraction as compared to 81% fourth-year students, with the difference being statistically significant (P value: 0.016).
CONCLUSION
Dental students in Riyadh city have a strong inclination toward a particular material, either for primary or secondary impressions or gingival retraction options.
PubMed: 34017780
DOI: 10.4103/jfmpc.jfmpc_2094_20 -
PloS One 2017The aim of this study was to evaluate and compare the inter-operator reproducibility of three-dimensional (3D) images of teeth captured by a digital impression technique... (Comparative Study)
Comparative Study
PURPOSE
The aim of this study was to evaluate and compare the inter-operator reproducibility of three-dimensional (3D) images of teeth captured by a digital impression technique to a conventional impression technique in vivo.
MATERIALS AND METHODS
Twelve participants with complete natural dentition were included in this study. A digital impression of the mandibular molars of these participants was made by two operators with different levels of clinical experience, 3 or 16 years, using an intra-oral scanner (Lava COS, 3M ESPE). A silicone impression also was made by the same operators using the double mix impression technique (Imprint3, 3M ESPE). Stereolithography (STL) data were directly exported from the Lava COS system, while STL data of a plaster model made from silicone impression were captured by a three-dimensional (3D) laboratory scanner (D810, 3shape). The STL datasets recorded by two different operators were compared using 3D evaluation software and superimposed using the best-fit-algorithm method (least-squares method, PolyWorks, InnovMetric Software) for each impression technique. Inter-operator reproducibility as evaluated by average discrepancies of corresponding 3D data was compared between the two techniques (Wilcoxon signed-rank test).
RESULTS
The visual inspection of superimposed datasets revealed that discrepancies between repeated digital impression were smaller than observed with silicone impression. Confirmation was forthcoming from statistical analysis revealing significantly smaller average inter-operator reproducibility using a digital impression technique (0.014± 0.02 mm) than when using a conventional impression technique (0.023 ± 0.01 mm).
CONCLUSION
The results of this in vivo study suggest that inter-operator reproducibility with a digital impression technique may be better than that of a conventional impression technique and is independent of the clinical experience of the operator.
Topics: Adult; Dental Impression Materials; Dental Impression Technique; Denture Design; Female; Humans; Image Processing, Computer-Assisted; Imaging, Three-Dimensional; Male; Materials Testing; Models, Dental; Reproducibility of Results
PubMed: 28636642
DOI: 10.1371/journal.pone.0179188 -
European Journal of Dentistry Oct 2023The aim of this study was to determine the effect of finish lines on the penetration ability of polyether and polyvinyl siloxane impression material into the...
OBJECTIVE
The aim of this study was to determine the effect of finish lines on the penetration ability of polyether and polyvinyl siloxane impression material into the simulated gingival sulcus.
MATERIALS AND METHODS
Three types of finish line (chamfer, deep chamfer, and radial shoulder) were impressed with two types of elastomeric impression material (polyether and polyvinyl siloxane) using a two-step impression technique. Ten samples of each finish line were prepared and then separated into two groups of impression material: polyether and polyvinyl siloxane. The model of the simulated gingival sulcus had a width of 0.1 mm and a depth of 3.5 mm with a subgingival finish line of 0.5 mm. The effect of the finish lines on the penetration ability of these impression materials was analyzed using a two-way analysis of variance (ANOVA) and Tukey's multiple comparison tests at a statistically significant level of 0.05.
RESULTS
A two-way ANOVA revealed a significant difference among finish lines, impression materials, and their interaction. The deep chamfer and radial shoulder finish lines displayed significantly higher penetration ability than the chamfer finish line. Moreover, polyether revealed significantly higher penetration ability than polyvinyl siloxane.
CONCLUSION
The finish lines affected the penetration ability of the impression materials. Therefore, the simulated gingival sulcus model demonstrates that it is an effective way of examining impression materials' penetration abilities.
PubMed: 36599449
DOI: 10.1055/s-0042-1759697 -
Journal of Indian Prosthodontic Society 2023The aim of this study was to evaluate and compare the accuracy of hexed and nonhexed pickup impression copings with and without splinting using polyether (PE) and...
Comparison of accuracy of hexed and nonhexed pickup impression copings in a multiple variable impression setup for recording multiple straight and angulated implant positions: An study.
AIM
The aim of this study was to evaluate and compare the accuracy of hexed and nonhexed pickup impression copings with and without splinting using polyether (PE) and polyvinyl siloxane (PVS) impression materials in open-tray technique in recording multiple straight and angulated implant positions.
SETTINGS AND DESIGN
An accurate impression results in an accurate definitive cast, thus minimizing the incidence of prosthesis misfit. The critical aspect is to record the three-dimensional location of the implant in bone rather than reproducing fine surface details. Precise fit of a fixed implant-supported prosthesis depends on the accuracy of the implant analog location within the definitive cast. Factors which affect impression accuracy include implant angulation, impression material, impression copings, technique, and splinting.
MATERIALS AND METHODS
A sample size of 80 study models fabricated from the impression of different groups was included. A reference master model based on All-on-4 implant concept with two parallel (implants 1 and 2) and two angulated (implant 3 at 17° and implant 4 at 30°) was fabricated using implant angulation guide. All impressions were recorded using open-tray impression technique. The groups were divided into two main groups of 40 samples each. Group A used hexed open-tray impression copings and Group B used nonhexed open-tray impression copings. Both the groups involved impression recording using splinted (Subgroup I) and nonsplinted impression copings (Subgroup II). Further, impressions in each subgroup were made using PE (Subsubgroups a) and PVS (Subsubgroup b). A total of eight subsubgroups with ten samples each were included. Impressions were recorded for each group and poured into Type IV die stone for fabrication of study models. After 24 h, the study models and reference master model were fitted with implant abutments for measurement with coordinate measuring machine.
STATISTICAL ANALYSIS USED
The mean differences of the interimplant distance R1 (1-2), R2 (1-3), R3 (2-4), and R4 (3-4) between the reference model and sample models in different subsubgroups were calculated and three-way analysis of variance test was applied with Tukey's post hoc tests.
RESULTS
No significant difference was found in mean coronal deviations for distance R1, R2, and R3 (P > 0.05) between different study groups. P = 0.02 for R4 (distance between 17° and 30° implants) between impression materials subsubgroups suggested that significantly less distortion was created in location of highly angulated implants (>30°) using PVS impression material. Splinting and type of coping did not have a significant influence on impression accuracy. Increasing angulation decreased the accuracy.
CONCLUSION
PVS was found equivalent in accuracy to rigid PE for recording parallel or angulated implants. Impressions of implants with higher angulations were recorded more accurately with PVS. The study found no difference in accuracy with or without splinting. Furthermore, nonhexed impression copings facilitate easier and accurate recording of multiple angulated implant location in bone.
Topics: Dental Implants; Dental Impression Technique; Models, Dental; Dental Impression Materials
PubMed: 36588371
DOI: 10.4103/jips.jips_218_22