Effect of water temperature on the fit of provisional crown margins during polymerization: An in vitro study

Abstract

Aim:To evaluate the effect of water temperature on the marginal fit of bis-acrylic composite provisional crown during resin polymerization.Materials and Methods:Precisely machined 10 brass master dies were designed to simulate molar teeth. Five brass dies were selected and precisely machined to simulate all ceramic crown preparation. An acrylic jaw replica was made in which brass dies were arranged equidistant from each other. A custom-made metallic tray was fabricated on the acrylic jaw replica to make polyvinyl siloxane impression matrix. Bis-acrylic composite resin provisional crowns were made using polyvinyl siloxane impression matrix. Provisional crowns were polymerized at room temperature (Group I direct technique, on dental stone cast; Group I indirect technique crowns) and at different water temperatures (Group II direct technique crowns). The vertical marginal gap between all the provisional crown margins and the finish line of brass dies was measured using a Research Stereomicroscope System.Results:The results were statistically analyzed using one-way analysis of variance (ANOVA) test and Newman–Keul's test. The results showed that crowns polymerized in 20°C and 30°C water had marginal gap approximately three times smaller than those polymerized in 30°C air, due to the reduced polymerization shrinkage.Conclusion:This study shows that crowns polymerized in 20°C and 30°C water had mean vertical marginal gap approximately three times smaller than those polymerized in 30°C air. It was approximately closer to that of crowns fabricated by indirect technique. Warmer water also supposedly hastens polymerization.

Interleukin-1β activity in gingival crevicular fluid of abutment teeth with temporary fixed restorations versus final fixed restorations: Prospective observational study

“…According to ( Herráez-Galindo et al, 2019 ), the PMMA CAD-CAM material showed biologic compatibility with gingival health as they facilitate the gingival fibroblasts adhesion and proliferation with subsequent formation of gingival barrier decreasing the bacterial colonization. These results are consistent with ( Ramkumar et al, 2012 , Naqash et al, 2019 , Jubhari, et al, 2019 ) that showed a better effect of the indirect fabrication technique of temporary restorations than that of direct techniques on gingival health.…”

The effect of fabrication techniques of temporary crowns on the gingiva health

“…Margin accuracy of the provisory is very important to protect teeth from physical, chemical, bacterial, and heat exposure and to maintain gingival tissue health. 10 The accuracy fit of provisory margin varies depending on manufacturing techniques and materials used. Provisory margins that manufactured with indirect techniques are considered to be more accurate than direct technique.…”

Effect of Heat Treatment on the Physical Properties of Provisional Crowns during Polymerization: An in Vitro Study

“…Therefore, the material used should resist fracture, offer a smooth, good-looking surface profile, be color-stable to resist staining from food and beverages and have an accurate marginal adaptation to protect the tooth. These properties are influenced by the curing temperature of the materials [ 8 ]. In addition, while the properties of provisional restoration depend on the type of material used, they appear to be not material specific but product specific [ 9 ].…”