-
International Journal of Environmental... Mar 2022CAD/CAM technologies have been embedded into the fabrication of removable partial denture (RPD). Various materials such as zirconia and polyetheretherketone (PEEK) are...
CAD/CAM technologies have been embedded into the fabrication of removable partial denture (RPD). Various materials such as zirconia and polyetheretherketone (PEEK) are developed for subtractive manufacturing. As for additive manufacturing, dental professionals have begun to use selective laser melting (SLM) techniques for fabricating metallic RPD frameworks. This report demonstrates a case rehabilitated with a maxillary telescopic crown-retained combining PEEK and zirconia material denture and a mandibular Kennedy Class I RPD fabricated with SLM techniques. First, a conventional impression was performed and the master cast was mounted with a centric relation record. Digital models were obtained using tabletop scanners and then the telescopic primary zirconia crowns were designed and milled. After transferring the intraoral distribution of primary crowns using pick-up impression, secondary PEEK crowns and framework were designed, milled, and veneered with composite resin. Mandibular framework was designed and constructed using SLM technique with Ti-6Al-4V. Definitive prostheses for both jaws were finished and delivered. Delivered prostheses functioned well for a one-year period. The was patient satisfied with the improvements in chewing function and esthetics. Both substrative and additive manufacturing techniques are suitable for framework fabrication. Further investigation is needed for improving the mechanical performance and long-term prognosis of digitally made prostheses.
Topics: Alloys; Benzophenones; Computer-Aided Design; Denture, Partial, Removable; Humans; Ketones; Lasers; Mouth Rehabilitation; Polyethylene Glycols; Polymers; Titanium; Zirconium
PubMed: 35270714
DOI: 10.3390/ijerph19053021 -
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 -
Marine Drugs Jan 2022This study aimed to investigate the potential use of brown algae as irreversible hydrocolloid (alginate) impression material. Potassium alginate extracted from was...
This study aimed to investigate the potential use of brown algae as irreversible hydrocolloid (alginate) impression material. Potassium alginate extracted from was prepared in three different compositions (14%, 15%, and 16%) and mixed with other standard components to form an alginate impression material. Prior to that, the purity of potassium alginate was quantified with Fourier Transform Infrared Spectroscopy (FTIR) analysis. As a control material, the alginate impression material from a commercially available product was used. All alginate impression materials were then applied to a die stone model. Dimensional accuracy was measured by calculating the mesiodistal width of incisors in the generated dental cast using a digital caliper 0.01 accuracy (five replications). In addition, to evaluate the dimensional stability, the impression results were poured at four different periods (immediately, 5 min, 10 min, and 15 min). An independent -test was performed to compare the measurement results with < 0.05 considered significant. Analytical results confirm that the impression material containing 15% potassium alginate gives the best dimensional accuracy similar to control ( > 0.05). Meanwhile, the optimal dimensional stability was produced in the impression material containing 16% potassium alginate. Our study suggested that brown algae has a promising potential to be used as an alginate impression material in clinical application.
Topics: Animals; Aquatic Organisms; Colloids; Dental Impression Materials; Materials Testing; Sargassum
PubMed: 35049910
DOI: 10.3390/md20010055 -
Clinical Oral Investigations Feb 2022To compare the failure rates for three different adhesively retained core build-up composites up to the incorporation of a permanent fixed dental prosthesis (FDP), and... (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVES
To compare the failure rates for three different adhesively retained core build-up composites up to the incorporation of a permanent fixed dental prosthesis (FDP), and to identify potential failure risk factors.
MATERIAL AND METHODS
A randomized controlled trial of 300 participants in need of a core build-up to restore a vital abutment tooth before prosthetic treatment was conducted. Participants were assigned by stratified block randomization to one of three study groups: Rebilda DC (RDC), Clearfil DC Core (CDC), or Multicore Flow (MF). Test teeth were prepared by use of the respective manufacturer's adhesive system. The total-etch technique was used for RDC and MF, and the self-etch technique for CDC. Participants were treated by dentists (n = 150) or dental students (n = 150). Failure rates of core build-ups before incorporation of FDPs were investigated using univariate and multiple logistic regression.
RESULTS
The overall failure rate was 8% (n = 23). Rate differences between the three investigated groups did not reach statistical significance (p > 0.05). The mean time between placement of core build-ups and placement of fixed dental prostheses was 12.2 (SD: 14.2) weeks. Conversely, larger cavities (> 3 surfaces) and treatment by dental students were independently associated with an increased failure risk (p < 0.05).
CONCLUSIONS
The main risk factors for early failure seem to be the size of the core build-up and clinical experience of the operator, whereas failure rates of core build-up materials combined with a self-etch approach seem to be similar to the rates of materials combined with the total-etch technique.
CLINICAL SIGNIFICANCE
This research article should give clinicians an impression of the short-term performance of different adhesively retained core build-ups using different adhesive techniques/materials. Moreover, predominant influencing factors for the success or failure should be pictured.
Topics: Dental Cements; Dental Restoration Failure; Humans; Post and Core Technique; Resin Cements
PubMed: 34491449
DOI: 10.1007/s00784-021-04170-6 -
Contemporary Clinical Dentistry 2020Surface detail reproduction (SDR) and dimensional stability of elastomeric impression material play a crucial role in fixed prosthodontics.
BACKGROUND
Surface detail reproduction (SDR) and dimensional stability of elastomeric impression material play a crucial role in fixed prosthodontics.
AIM AND OBJECTIVES
The aim of this study was to compare the effect of chemical disinfection on SDR and dimensional stability of polyvinyl siloxane (PVS) and polyether (PE) with a new vinyl polyether silicone (VPES) elastomeric impression material.
MATERIALS AND METHODS
A stainless steel mold was made to fabricate the study specimens for nonaqueous PVS, PE, and VPES elastic dental impression materials. Single mix impression techniques with light- and heavy-body consistency of all three materials were used to prepare the test specimens. The specimens were immersed in glutaraldehyde (Cidex) 2.45% and sodium hypochlorite (Hypo) 3.0% disinfection for 15 min (T1) and 12 h (T2) immersion after which dimensional stability and SDR were recorded using stereomicroscope and digital Vernier caliper.
STATISTICAL ANALYSIS
The data were analyzed using the one-way ANOVA, paired -test, Kruskal-Wallis test, and Wilcoxon signed-rank test.
RESULTS
Dimensional stability at the T2 time interval showed a highly significant difference for control and glutaraldehyde groups ( < 0.001), whereas a statistically significant difference for Hypo group ( < 0.05). SDR of the three materials when compared at T1 time interval showed a statistically significant difference ( = 0.015). A comparison between two disinfectants at T1 time interval revealed a highly significant difference ( < 0.001), while at T2 interval significant difference was obtained ( = 0.009).
CONCLUSION
VPES impressions display acceptable dimensional stability and SDR for clinical use with immersion disinfection. Although some statistically significant differences in linear dimensional stability and semidefinite programming were observed among VPES, PE, and PVS, but the clinical impact of these differences is minor considering the overall accuracy of casts which was high.
PubMed: 33110302
DOI: 10.4103/ccd.ccd_9_19 -
British Medical Journal Jun 1974The technique of repairing defects of the skull with titanium is described. The skull contour can be accurately reproduced. The technique is simpler than wiring or...
The technique of repairing defects of the skull with titanium is described. The skull contour can be accurately reproduced. The technique is simpler than wiring or suturing methods. The material is inert, radiolucent, and rigid.
Topics: Calcium Sulfate; Dental Impression Materials; Humans; Methods; Prostheses and Implants; Radiography; Skull; Skull Fractures; Titanium; Wounds, Gunshot
PubMed: 4834099
DOI: 10.1136/bmj.2.5917.478 -
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 -
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 -
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