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Journal of Maxillofacial and Oral... Dec 2014Demonstrations and training on live-subjects are not always the optimal means of introducing the students to minor oral surgery. Hence, the use of teaching models permit...
INTRODUCTION
Demonstrations and training on live-subjects are not always the optimal means of introducing the students to minor oral surgery. Hence, the use of teaching models permit the students to handle the surgical instruments in a limited field under a semi-realistic circumstance and also helps in developing psychomotor skills in an non stressed situation. One among the competent exercise in oral surgery is suturing. Though there exist a variety of commercially available suturing training models, cost factor restrain their acquirement in few units.
METHODS & MATERIALS
This paper describes the construction of a simple and cost-effective suturing model for preclinical training. The construction of this model requires an orange peel, putty impression material and plaster of paris. This suturing model can be created in ten minutes.
CONCLUSION
This model can be constructed by the students with minimal effort and low cost in order to practice suturing.
PubMed: 26225037
DOI: 10.1007/s12663-013-0546-z -
Medical Science Monitor : International... Nov 2023BACKGROUND The aim of this study was to assess and compare the vertical/horizontal dimensions and occlusal accuracy of non-working/opposing casts obtained from three...
BACKGROUND The aim of this study was to assess and compare the vertical/horizontal dimensions and occlusal accuracy of non-working/opposing casts obtained from three different impression materials and 3D print cast. MATERIAL AND METHODS Dentulous Master models simulating a case of a fixed dental prosthesis were mounted on an articulator (control group). Opposing mandibular casts obtained from three different impression materialsand 3-dimensional print constituted test groups , ,and , respectively. Three points, anterior vertical (AV), posterior vertical (PV), and anteroposterior (AP) were compared for dimensional accuracy among casts. Occlusal accuracy was analyzed on Medit Link software at 3 teeth (#13, #17, and #27). After calculating means for each group, the differences were calculated at probability value of P≤0.05 using the single-sample t test, ANOVA, and Tukey test. RESULTS The dimensions were significantly different from those of the mounted master models except in Gp AL(E) and Gp AL(F) at AV dimension and Gp AL(E) at AP dimension (P>0.05). A statistically significant difference of the error of means among the 4 tested groupswere detected only at 2 dimensions (AV and PV) between the Gp AL(E) and Gp 3D-C and between Gp AL(F) and Gp 3D-C groups. Other groups showed no significant differences. CONCLUSIONS The opposing casts obtained from the extended-pour alginate and alginate alternative impression materials showed higher occlusal accuracy compared to conventional alginate and 3D printed casts.
Topics: Humans; Alginates; Mandible; Models, Dental; Printing, Three-Dimensional; Software
PubMed: 37924203
DOI: 10.12659/MSM.941654 -
European Oral Research May 2021The present study compared the dimensional accuracy of vinyl polyether silicone (VPES) and polyvinyl siloxane (PVS) impression materials used for non-splinted (NS) and...
PURPOSE
The present study compared the dimensional accuracy of vinyl polyether silicone (VPES) and polyvinyl siloxane (PVS) impression materials used for non-splinted (NS) and splinted (S) direct open-tray impression techniques for multiple implants inserted in simulated edentulous mandibles.
MATERIALS AND METHODS
A mandibular stainless steel model with eight internal connections for implant analogs was fabricated to simulate a clinical scenario. The acrylic resin splinted and non-splinted direct impressions were obtained for both VPES and PVS materials. Seventy-two cast samples were divided into four groups based on the impression techniques and materials used. The dimensional accuracies of the casts were measured in three different axes using a computerized coordinate measuring machine (CMM), and were statistically compared.
RESULTS
The differences in the distortion values between the VPES and PVS impression materials were not statistically significant. Similarly, the differences between the splinted and non-splinted groups among the VPES and PVS materials were not statistically significant.
CONCLUSION
The casts fabricated from VPS or PVS impression materials provide similar dimensional accuracy regardless of the implant splinting method.
PubMed: 34250470
DOI: 10.26650/eor.20210110 -
Indian Journal of Dental Research :... Oct 20233D printing technology is replacing manual fabrication in all fields. 3D-printed impression trays should be assessed as they could replace conventional impression trays... (Comparative Study)
Comparative Study
BACKGROUND
3D printing technology is replacing manual fabrication in all fields. 3D-printed impression trays should be assessed as they could replace conventional impression trays in the future.
AIM
In-vitro comparison and evaluation of the dimensional stability and retention strength of impressions to custom impression trays fabricated using conventional method and additive technology.
MATERIALS AND METHODS
A maxillary edentulous auto-polymerizing acrylic resin model served as the master model. Two moulds were prepared from the master model in order to obtain 12 casts. One cast was scanned for 3D printing digital light processing (DLP) and fused deposition modelling (FDM) 24 impression trays using polylactic acid (PLA). Twelve casts were used to fabricate light cure impression trays. Polyvinyl-siloxane impressions were made on the master model using 36 impression trays and 18 trays each were used to assess dimensional stability and retention strength.
RESULTS
In dimensional stability analysis, one sample t-test revealed a statistically significant difference between each group and the master model followed by a one-way ANOVA. There were significant differences, but the difference was less with FDM trays (P < 0.05). In retention strength analysis, one-way Analysis of variance (ANOVA) revealed statistically significant difference between each group and post-hoc test revealed specific difference, the highest with FDM trays (P < 0.05).
CONCLUSION
Dimensional changes were observed at 30 minutes and 72 hours. Lesser dimensional changes were observed when impressions were made using FDM trays followed by DLP and light cure trays. The mean retention strength seen in descending order was FDM, followed by DLP and light cure trays. The best retention strength was noticed when impressions were made using FDM trays.
Topics: Dental Impression Technique; Dental Impression Materials; Printing, Three-Dimensional; Polyvinyls; Siloxanes; Humans; In Vitro Techniques; Models, Dental; Materials Testing
PubMed: 38739826
DOI: 10.4103/ijdr.ijdr_519_23 -
BMC Oral Health Apr 2023Dental materials science is an important core course in undergraduate dental programs which integrates foundational concepts of chemical engineering and materials...
BACKGROUND
Dental materials science is an important core course in undergraduate dental programs which integrates foundational concepts of chemical engineering and materials science into clinical dentistry. The present study aimed to identify relevant dental materials science topics for Malaysian undergraduate dental curricula and to determine their appropriate competency levels in terms of cognitive and psychomotor taxonomies.
METHODS
Potential dental materials science topics were drafted in alignment with the revised national competency statement. The list of topics was further amended after comparing it with those recommended topics in the literature. Fuzzy Delphi method was applied. Experts were selected based on the different inclusion criteria. They ranked the topics using a five-point Likert scale and recommended the appropriate cognitive and psychomotor levels. Next, fuzzy evaluation was performed. Consensus was deemed for a topic to be included if (a) the average expert agreement was ≥ 75%, (b) the d-construct threshold value for each topic was ≤ 0.2 and (c) the average fuzzy number was ≥ 0.5.
RESULTS
Sixty-two experts participated in the study. They accepted 33 out of 36 potential dental materials science topics. The average Likert score and fuzzy number ranged from 3.63 to 4.92 and 0.526 to 0.784, respectively. Furthermore, "Endodontic materials" was ranked as the most significant topic. Meanwhile, many topics required dental students to demonstrate a cognitive level of "Apply" and a psychomotor level of "Guided response". Based on mean scores, "Impression materials" was rated as the most cognitively demanding topic, whilst "Temporary restorative materials" was the most demanding topic for psychomotor taxonomy.
CONCLUSION
The present study has identified relevant dental materials science topics and their appropriate cognitive and psychomotor levels using the Fuzzy Delphi approach. The findings of the present study form the basis for future studies to develop measurable learning outcomes, design corresponding innovative pedagogy and propose assessment criteria for each topic.
Topics: Humans; Delphi Technique; Materials Science; Curriculum; Learning; Consensus
PubMed: 37106354
DOI: 10.1186/s12903-023-02946-8 -
Journal of Applied Oral Science :... 2023The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated...
OBJECTIVE
The use of a fiber glass post (FGP) type and choice of FGP diameter to restore endodontically treated incisors without ferrule is controversial. This study evaluated survival rate and failure mode of severely compromised central incisors without ferrule rehabilitated using resin-based composite (RBC) with or without FGP with different diameters.
METHODOLOGY
A total of 60 decoronated bovine incisors without a ferrule were endodontically treated and prepared for 1.4, 1.6, and 1.8 mm diameter FGPs (Whitepost System DC 0.5, Fit 0.4, and DCE 0.5; FGM). Half of the teeth received FGPs cemented using dual-cure resin cement (Allcem Core; FGM), the other half were filled using only bulk-fill RBC (OPUS Bulk Fill; FGM). The crowns were directly restored with RBC. The roots were embedded in polystyrene resin and the periodontal ligament was simulated with polyether impression material. Fatigue testing was conducted under 5 Hz cyclic loading at 30 degrees to the incisal edge, beginning at 50 N (5,000 cycles) as a warmup. After, the load was increased 100 N every 15,000 cycles until fracture occurred. All specimens were subjected to transillumination, micro-CT analysis, and digital radiography before and after fatigue testing. Fracture mode was classified according to severity and repair potential. Data were analyzed with Kaplan-Meier survival test and post hoc log-rank test (α=0.05) for pairwise comparisons.
RESULTS
Using FGP significantly increased the number of cycles to failure, irrespective of FGP diameters (p=0.001). The FGP diameters had no statistically significant effect on cycles to failure or failure mode.
CONCLUSION
Using FGP without ferrule improved survival rate of structurally severely compromised central incisors compared with rehabilitation without FGP. The diameter of the FGPs had no effect on the survival rate and failure mode.
Topics: Animals; Cattle; Post and Core Technique; Composite Resins; Tooth, Nonvital; Crowns; Dental Materials; Glass; Dental Stress Analysis; Tooth Fractures; Dental Restoration Failure
PubMed: 37909530
DOI: 10.1590/1678-7757-2023-0241 -
Journal of Dentistry Mar 2024To measure the impact of the scanning distance on the accuracy of complete-arch implant scans acquired by using a photogrammetry (PG) system.
PURPOSE
To measure the impact of the scanning distance on the accuracy of complete-arch implant scans acquired by using a photogrammetry (PG) system.
MATERIAL AND METHODS
An edentulous cast with 6 implant abutment analogs was obtained. A brand new implant scan body was positioned on each implant abutment and digitized using an extraoral scanner (T710; Medit) and the reference file was obtained. Three groups were created based on the scanning distance used to acquire complete-arch implant scans by using a PG (PIC System; PIC Dental): 20 (20 group), 30 (30 group), and 35 cm (35 group). An optical marker (PIC Transfer, HC MUA Metal; PIC Dental) was placed on each implant abutment and a total of thirty scans per group were acquired. Euclidean linear and angular measurements were obtained on the reference file was obtained and used to compare the discrepancies with the same measurements obtained on each experimental scan. One-way ANOVA and Tukey tests were used to analyze trueness. The Levene test was used to analyze the precision values (α = 0.05).
RESULTS
Significant linear (P < .001) and angular trueness (P < .001) discrepancies were found among the groups. For linear trueness, Tukey test showed that the 20 and 30 groups (P < .001) and 30 and 35 groups were different (P < .001). For angular trueness, the Tukey test revealed that 20 and 30 groups (P = .003), 20 and 35 (P < .001), and 30 and 35 groups were different (P < .001) The Levene test showed no significant linear precision (P = .197) and angular discrepancies (P = .229) among the groups.
CONCLUSIONS
The scanning distance influenced the trueness of complete-arch implant scans obtained with the PG method tested. The maximum linear trueness mean discrepancy among the groups tested was 10 µm and the maximum angular trueness mean discrepancy among the groups tested was 0.02 .
Topics: Humans; Dental Impression Technique; Models, Dental; Computer-Aided Design; Imaging, Three-Dimensional; Mouth, Edentulous; Dental Implants
PubMed: 38246309
DOI: 10.1016/j.jdent.2024.104854 -
BMC Oral Health Sep 2022This study aimed to compare the dimensional accuracy, hydrophilicity and detail reproduction of the hybrid vinylsiloxnether with polyether and polyvinylsiloxane parent...
BACKGROUND
This study aimed to compare the dimensional accuracy, hydrophilicity and detail reproduction of the hybrid vinylsiloxnether with polyether and polyvinylsiloxane parent elastomers using modified digital techniques and software. This was done in an attempt to aid in solving the conflict between the different studies published by competitive manufacturers using different common manual approaches.
METHODS
A polyether, polyvinylsiloxanes and vinyl polyether silicone hybrid elastomeric impression materials were used in the study. Dimensional accuracy was evaluated through taking impressions of a metallic mold with four posts representing a partially edentulous maxillary arch, that were then poured with stone. Accuracy was calculated from the mean of measurements taken between fixed points on the casts using digital single-lens reflex camera to produce high-resolution digital pictures for all the casts with magnification up to 35×. Hydrophilicity was assessed by contact angle measurements using AutoCAD software. The detail reproduction was measured under dry conditions according to ANSI/ADA Standard No. 19 and under wet conditions as per ISO 4823. A metallic mold was used with three V shaped grooves of 20, 50, and 75 µm width. Specimens were prepared and examination was made immediately after setting using digital images at a magnification of 16×.
RESULTS
The hybrid impression (0.035 mm) material showed significantly higher dimensional accuracy compared to the polyether (0.051 mm) but was not as accurate as the polyvinyl siloxane impression material (0.024 mm). The contact angles of the hybrid material before and after setting was significantly lower than the parent materials. With regard to the detail reproduction, the three tested materials were able precisely to reproduce the three grooves of the mold under dry conditions. Whereas, under wet conditions, the hybrid material showed higher prevalence of well-defined reproduction of details same as polyether but higher than polyvinylsiloxane that showed prevalence of details with loss of sharpness and continuity.
CONCLUSIONS
The digital technique used could be a more reliable and an easier method for assessment of impression materials properties. The hybridization of polyvinyl siloxane and polyether yielded a promising material that combines the good merits of both materials and overcomes some of their drawbacks.
Topics: Dental Impression Materials; Dental Impression Technique; Elastomers; Humans; Materials Testing; Polyvinyls; Silicones; Siloxanes; Surface Properties
PubMed: 36064393
DOI: 10.1186/s12903-022-02419-4 -
PeerJ 2023To systematically evaluate the disinfection efficacy of the two most frequently used disinfectants, sodium hypochlorite and glutaraldehyde, and their effects on the...
Disinfection efficacy of sodium hypochlorite and glutaraldehyde and their effects on the dimensional stability and surface properties of dental impressions: a systematic review.
OBJECTIVE
To systematically evaluate the disinfection efficacy of the two most frequently used disinfectants, sodium hypochlorite and glutaraldehyde, and their effects on the surface properties of four different dental impression materials.
METHODS
A systematic literature search was performed in four databases until May 1st, 2022 to select the studies which evaluated disinfection efficacy of disinfectants or surface properties of dental impressions after chemical disinfection.
MAIN RESULTS
A total of 50 studies were included through electronic database searches. Of these studies, 13 studies evaluated disinfection efficacy of two disinfectants, and 39 studies evaluated their effects on the surface properties of dental impressions. A 10-minute disinfection with 0.5-1% sodium hypochlorite or 2% glutaraldehyde was effective to inactivate oral flora and common oral pathogenic bacteria. With regard to surface properties, chemical disinfection within 30 min could not alter the dimensional stability, detail reproduction and wettability of alginate and polyether impressions. However, the wettability of addition silicone impressions and the dimensional stability of condensation silicone impressions were adversely affected after chemical disinfection, while other surface properties of these two dental impressions were out of significant influence.
CONCLUSIONS
Alginate impressions are strongly recommended to be disinfected with 0.5% sodium hypochlorite using spray disinfection method for 10 min. Meanwhile, elastomeric impressions are strongly recommended to be disinfected with 0.5% sodium hypochlorite or 2% glutaraldehyde using immersion disinfection method for 10 min, however, polyether impression should be disinfected with 2% glutaraldehyde.
Topics: Sodium Hypochlorite; Glutaral; Disinfection; Time Factors; Disinfectants; Surface Properties; Silicones; Alginates; Bacteria
PubMed: 36846444
DOI: 10.7717/peerj.14868 -
Polymers Apr 2024The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based,...
The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones-from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann-Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards ( < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique.
PubMed: 38611252
DOI: 10.3390/polym16070994