scholarly journals The Effects of Custom Tray Material on the Accuracy of Master Casts

2008 ◽  
Vol 9 (6) ◽  
pp. 49-56 ◽  
Author(s):  
Ramin Mosharraf ◽  
Sina Shafa ◽  
Zeinab Zaree
Keyword(s):  
Stainless Steel ◽  
Visible Light ◽  
Polymethyl Methacrylate ◽  
Impression Material ◽  
Significant Difference ◽  
Irreversible Hydrocolloid ◽  
Light Curing ◽  
Master Model ◽  
Visible Light Curing ◽  
Digital Caliper

Aim In addition to the impression material, the type of impression tray influences the accurate dimensional transfer of the size and position of the teeth to the master cast. The aim of this study was to determine the accuracy of master casts produced from an alginate impression material using a visible-light-curing resin and autopolymerizing polymethyl methacrylate resin custom tray materials. Methods and Materials Two types of custom trays were fabricated from a stainless steel master model with three index studs. Twenty-two irreversible hydrocolloid impressions were made of the master model and then poured with a Type III dental stone. The distances between the reproduced index studs were measured to +/- 0.01 mm with a digital caliper. A one-way analysis of variance (ANOVA) and T-test were used for data analysis. Results There were no significant differences between the two tray materials for any of the three distances. There were no statistical differences between the master model and the casts made from the two tray materials in the length dimension, but there were significant differences in the vertical dimension. In terms of the width dimension there was a significant difference only between the cold curing group and the master model. Conclusion Within the limitations of this study, the dimensions of stone casts poured from an impression made using a light-cured tray did not differ significantly from those created from impressions made using autopolymerizing acrylic trays. However, working dies from the light-curing tray impressions were more accurate buccolingually than those from the autopolymerizing acrylic trays. Clinical Significance The accuracy of master cast reproduction using visible-light-curing resin or an autopolymerizing polymethyl methacrylate resin custom tray material is acceptable. Although autopolymerizing resin materials require less equipment and are relatively more inexpensive, light-cure tray materials may be the material of choice for custom tray fabrication due to greater accuracy in the buccolingual dimension. Citation Shafa S, Zaree Z, Mosharraf R. The Effects of Custom Tray Material on the Accuracy of Master Casts. J Contemp Dent Pract 2008 September; (9)6:049-056.

scholarly journals Linear dimensional stability of irreversible hydrocolloids with and without disinfection at different storage times

RSBO ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 77
Author(s):  
Lidia Olga Bach Pinheiro ◽  
Alfonso Sanchez Ayala ◽  
Marcos Cezar Pomini ◽  
Vanessa Taborda da Cruz ◽  
Ingrid Viel del Farias ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Dimensional Stability ◽  
Storage Time ◽  
Dental Practice ◽  
Type Iv ◽  
Significant Difference ◽  
Irreversible Hydrocolloid ◽  
Master Model ◽  
Storage Times ◽  
Digital Caliper

Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-way followed by Tukey’s test (α < 0.05). Results: A statistically significant difference was detected with Jeltrate Plus after 72 and 120 hours in storage (with and without disinfection), as well as Cavex without disinfection. Differences were found for Cavex with disinfection/24 hours storage, when compared to immediate pouring (P < 0.05). The alginates presented similar behavior regarding disinfection for the same time (P > 0.05). Conclusion: Storage longer than 24 hours affects the fidelity of casts. Disinfection does not promote significant alteration at any of the experimental times with either material.

scholarly journals Linear dimensional stability of irreversible hydrocolloids with and without disinfection at different storage times

RSBO ◽  
2018 ◽  
Vol 15 (2) ◽  
pp. 77-83
Author(s):  
Lidia Olga Bach Pinheiro ◽  
Alfonso Sanchez Ayala ◽  
Marcos Cezar Pomini ◽  
Vanessa Taborda da Cruz ◽  
Ingrid Viel del Farias ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Dimensional Stability ◽  
Storage Time ◽  
Dental Practice ◽  
Type Iv ◽  
Significant Difference ◽  
Irreversible Hydrocolloid ◽  
Master Model ◽  
Storage Times ◽  
Digital Caliper

Irreversible hydrocolloids have been used in dental practice for decades and their pouring time has been suggested to be as short as possible; however the latest generation of alginates exhibit better properties, which could influence the fidelity of the casts. Objective: To evaluate the linear dimensional stability of stone casts obtained using two irreversible hydrocolloid brands (Cavex ColorChange and Jeltrate) after disinfection. Material and methods: Samples were divided into 16 groups (n = 10) according to brand, storage time and disinfection. Impressions were taken of a metallic master model made of stainless steel with two abutments. Cast models were obtained using type IV gypsum, after disinfection with sodium hypochlorite at 1% or without any disinfection followed by storage for four different times (immediate pouring, and after 24, 72 or 120 hours storage after obtaining the impressions) and the models were measured with a digital caliper. Data were submitted to ANOVA 3-way followed by Tukey’s test (α < 0.05). Results: A statistically significant difference was detected with Jeltrate Plus after 72 and 120 hours in storage (with and without disinfection), as well as Cavex without disinfection. Differences were found for Cavex with disinfection/24 hours storage, when compared to immediate pouring (P < 0.05). The alginates presented similar behavior regarding disinfection for the same time (P > 0.05). Conclusion: Storage longer than 24 hours affects the fidelity of casts. Disinfection does not promote significant alteration at any of the experimental times with either material.

scholarly journals Synthesis, Characterization, and Visible Light Curing Capacity of Polycaprolactone Acrylate

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Jy-Jiunn Tzeng ◽  
Yi-Ting Hsiao ◽  
Yun-Ching Wu ◽  
Hsuan Chen ◽  
Shyh-Yuan Lee ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Visible Light ◽  
Room Temperature ◽  
Low Viscosity ◽  
Nuclear Magnetic Resonance Spectra ◽  
Light Curing ◽  
Soft Tissue Engineering ◽  
The Fourier Transform ◽  
Visible Light Curing

Polycaprolactone (PCL) is drawing increasing attention in the field of medical 3D printing and tissue engineering because of its biodegradability. This study developed polycaprolactone prepolymers that can be cured using visible light. Three PCL acrylates were synthesized: polycaprolactone-530 diacrylate (PCL530DA), glycerol-3 caprolactone triacrylate (Glycerol-3CL-TA), and glycerol-6 caprolactone triacrylate (Glycerol-6CL-TA). PCL530DA has two acrylates, whereas Glycerol-3CL-TA and Glycerol-6CL-TA have three acrylates. The Fourier transform infrared and nuclear magnetic resonance spectra suggested successful synthesis of all PCL acrylates. All are liquid at room temperature and can be photopolymerized into a transparent solid after exposure to 470 nm blue LED light using 1% camphorquinone as photoinitiator and 2% dimethylaminoethyl methacrylate as coinitiator. The degree of conversion for all PCL acrylates can reach more than 80% after 1 min of curing. The compressive modulus of PCL530DA, Glycerol-3CL-TA, and Glycerol-6CL-TA is 65.7±12.7, 80.9±6.1, and 32.1±4.1 MPa, respectively, and their compressive strength is 5.3±0.29, 8.3±0.18, and 3.0±0.53 MPa, respectively. Thus, all PCL acrylates synthesized in this study can be photopolymerized and because of their solid structure and low viscosity, they are applicable to soft tissue engineering and medical 3D printing.

scholarly journals The Influence of Different Light Curing Modes on the Depth of Cure of the Composite Resin

2018 ◽  
Vol 35 (1) ◽  
pp. 58-64
Author(s):  
Nikola Miljković ◽  
Stefan Dačić ◽  
Tamara Karuntanović ◽  
Marko Igić ◽  
Milica Dačić ◽  
...  
Keyword(s):  
Composite Resin ◽  
Composite Layer ◽  
Composite Specimen ◽  
Depth Of Cure ◽  
Average Value ◽  
Clinical Recommendation ◽  
Significant Difference ◽  
Light Curing ◽  
Metal Block ◽  
Digital Caliper

Summary The aim of this study was to investigate the influence of different light curing modes on the depth of cure of the composite resin. The metal block with formed round holes served as a mold for the placement of the composite resin. The composite resin was cured with Penguin DB-685 lamp with four optional working modes: strong, low, gradually strong, and flashing. Unpolymerized part of the composite specimen was removed by scraping with a plastic spatula, and then each specimen was placed into the capsule with 1 ml of ethanol alcohol and mixed for 20 s in amalgamator. The length of the remaining composite specimen was measured with the digital caliper with a precision of 0.01 mm. The measured values were divided by 2 (according to ISO 4049 standard) and then statistically processed. Based on the measured lengths of the polymerized part of the composite specimens, the lowest average value of the depth of cure (2.75 ± 0.08 mm) was determined after polymerization with the low mode and the highest value was obtained (2.98 ± 0.08 mm) with strong polymerization mode. Statistically significant difference (p < 0.05) was determined between low polymerization mode and all other modes (strong, gradually strong and flashing mode). The observed statistically significant differences are not clinically important because all curing modes provided the necessary depth of cure, which is in accordance with the clinical recommendation of 2 mm thick composite layer.

The use of visible light-curing resin for vertebral body replacement

1991 ◽  
Vol 75 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Ricardo Segal ◽  
Moufid Alsawaf ◽  
Ali Tabatabai ◽  
Reisuke Saito ◽  
Eduardo D. Segal ◽  
...  
Keyword(s):  
Visible Light ◽  
Methyl Methacrylate ◽  
Vertebral Body ◽  
Vertebral Body Replacement ◽  
Halogen Lamp ◽  
Content Type ◽  
Spinal Implant ◽  
Light Curing ◽  
Visible Light Curing ◽  
Fine Print

✓ The technology of visible light-curing resin has recently been developed for use in removable prosthodontics. A quartz halogen lamp producing a 400- to 500-nanometer wave-length spectrum of visible light is used to polymerize high-molecular-weight acrylic resin monomers. While several in vitro and in vivo studies of visible light-curing resin are found in the dental literature, no studies have yet been performed to evaluate it as an intracorporeal implant in surgery. The authors have designed a rat model of microcervical corpectomy to assess vertebral body replacement with visible light-curing resin in comparison to conventional autopolymerizing methyl methacrylate. Spinal cord function tests, spinal-implant stability assessments, and histological evaluations were made in a total of 41 rats at 2, 4, or 6 months postimplant. No animal developed a neurological deficit or radiographic instability, and at sacrifice there was no evidence of implant fracture-extrusion. In addition, there were no signs of adverse reaction in the surrounding tissues. Morphological investigation of the resin/bone interface at 6 months revealed very good implant anchorage. Visible light-curing resin was found to be far superior to methyl methacrylate for construction of spinal implants. Its waxy consistency makes it easy to handle. It remains pliable until light is applied, allowing adjustments in shape for a well-fitted implant without time constraints. Applied in layers, adjustments can be made even after polymerization of a previous layer. This new implantable resin will allow safer, immediate stabilization in patients with neoplastic destruction of the spine, and may also be advantageous for other neurosurgical applications, such as cranioplasty.

A synergistic effect of a ferrocenium salt on the diaryliodonium salt-induced visible-light curing of bisphenol-A epoxy resin

RSC Advances ◽  
2015 ◽  
Vol 5 (42) ◽  
pp. 33171-33176 ◽  
Author(s):  
Yu Chen ◽  
Xiaoqin Jia ◽  
Mengqiang Wang ◽  
Tao Wang
Keyword(s):  
Electron Transfer ◽  
Synergistic Effect ◽  
Bisphenol A ◽  
Visible Light ◽  
Epoxy Resin ◽  
Halogen Lamp ◽  
Diaryliodonium Salt ◽  
Light Curing ◽  
Visible Light Curing

Diaryliodonium and ferrocenium salts undergo photo-electron transfer (PET) to initiate photopolymerizations under a halogen lamp.

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