ABSTRACT
AIM: The present in vitro study aimed to evaluate the transverse strength of heat cure acrylic denture base resins repaired with three different joint surface designs, repair material being the glass-fiber-reinforced self-cure repair material along with surface pretreatment. MATERIALS AND METHODS: A total of 40 heat cure resin specimens were fabricated and finished to a size of 64 mm × 10 mm × 2.5 mm. These specimens were divided into four groups of 10 each, with butt, round, and bevel repair surface joints, respectively, along with the control group. After the specimens were cut in the middle for the repair procedure to proceed, the aforementioned joint surface contours were prepared for groups I, II, and III, respectively, treated with dimethyl chloride for 30 seconds, and the repair was done with E-glass-fiber-reinforced self-cure repair material. RESULTS: The mean transverse strength of the control group was 100.37 N, which was highest (significant p value of <0.05), followed by group III (bevel joint) 54.23 N, group I (butt joint) 53.93 N, and group II (round joint) 44.55 N. CONCLUSION: Distribution of stresses evenly in the repair region will be achieved by the proper selection of the joint surface contour, and this study showed that the 45° bevel joint was an appropriate selection along with promising repair material and surface pretreatment. CLINICAL SIGNIFICANCE: Clinically, in the event of repairing a broken denture, a rapid and economically convenient material with superior physical and mechanical properties is important to maintain the adequate transverse strength of the repaired denture. Glass-fiber-reinforced autopolymerizing resin, with a 45° bevel joint design of the broken surfaces and surface pretreatment proved to reduce stress concentration, improving the transverse strength of the repaired heat cure denture base resins.
Subject(s)
Denture Bases , Hot Temperature , Denture Repair , Materials TestingABSTRACT
INTRODUCTION: An accurate impression is one of the prime factors for success of any restoration, more so in field of fixed prosthodontics. The critical aspect is to reproduce fine surface details along with ease of use. Knowledge of impression materials and the techniques to which each is best suited is essential in achieving consistent results. OBJECTIVE OF THE STUDY: The purpose of this study is to evaluate the accuracy of various putty-wash techniques in a laboratory model that simulated the clinical practice. MATERIALS AND METHODS: A metal master model, containing three full crowns fixed partial denture (FPD) abutment preparations, was fabricated. A perforated custom tray was fabricated that can be placed in the same position on the master model for each impression. For each technique, 10 impressions of the master model were made and poured using a die stone. The measurements were made of the models using a measuroscope and the accuracy of the impressions was recorded. RESULTS: The statistical comparison between groups I, II, III, and IV casts measurements by using the Mann-Whitney test showed highly significant statistical difference between the various groups from each other (p < 0.001). CONCLUSION: The accuracy of the working casts obtained from group III impression (two-step using 1 mm coping) was the best, whereas it was least with group II impression (two-step using polyethylene spacer). HOW TO CITE THIS ARTICLE: Gautam N, Ahmed R, Sharma S, et al. A Comparative Study to Evaluate the Accuracy of Various Spacer Thickness for Polyvinyl Siloxane Putty-wash Impression Techniques: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(5):536-542.