Citation Information :
Saini N, Aggarwal R, Choudhary S, Tyagi R, Malethia A. Comparative Analysis of Marginal Accuracy of Complete Crowns Fabricated by Using Ringless and Metal Ring Investment Systems: An In Vitro Study. J Contemp Dent Pract 2020; 21 (8):852-856.
Aim: To compare the vertical margin accuracy of lost wax castings produced by the conventional casting technique with all metal (WIRONIUM®) and PFM alloy (WIRON®99) using a metal ring and ringless system. Materials and methods: A brass die assembly was used to fabricate standardized wax pattern crowns. A total of 100 wax patterns were made with both ringless and metal ring investment systems. Wax patterns were readapted and refined on the master die and divided into two groups, namely, group I and group II with 50 wax patterns in each group. Group I (ringless system) and group II (metal ring system) were further divided into subgroups having a sample size of 25 in each group. Each coping was invested and cast individually. The marginal discrepancy between the metal die and the castings were measured by a stereomicroscope and AutoCAD software 2013. Measurement was made on the facial area of the metal die. Results: The resultant casts obtained from different casting systems show statistically significant difference found between the marginal discrepancies using metal ring and ringless castings system, and statistically nonsignificant difference was found between the marginal discrepancies using all metal alloy (WIRONIUM®) and PFM alloy (WIRON®99) within the same group. Conclusion: The marginal discrepancy for castings made with ringless casting system was less when compared to metal ring casting system, and there was no difference in marginal discrepancy when compared to all metal alloy (WIRONIUM®) and PFM alloy (WIRON®99) within the same group. Clinical significance: Marginal fit is influenced by several factors including type of crown, tooth preparation geometry, dimensional accuracy of impression materials, factors related to dental casting, type of cement, luting pressure, duration of cementation, and use of occlusal vents or die spacers.
Smith CD, Twiggs SW, Fairhurst CW, et al. Determining the marginal discrepancy of cast complete crowns. J Prosthet Dent 1985;54(6):778–784. DOI: 10.1016/0022-3913(85)90469-X.
Alex D, Shetty B, Miranda GA, et al. Marginal accuracy of nickel chromium copings fabricated by conventional and accelerated casting procedures, produced with ringless and metal ring investment procedures: A comparative in vitro study. Int J Prosthodont 2015;15(1):58–61. DOI: 10.4103/0972-4052.155043.
Muddugangadhar BC, Garg A, Mawani D, et al. Comparison of marginal accuracy of full metal crowns with various marginal configurations and casting techniques: an in vitro study. Int J Oral Health Med Res 2017;4(1):25–28.
Winkler S, Morris HF, Monteiro JM. Changes in mechanical properties and microstructure following heat treatment of a nickel–chromium base alloy. J Prosthet Dent 1984;52(6):821–827. DOI: 10.1016/S0022-3913(84)80012-8.
Silver M, Klein G, Howard MC. An evaluation and comparison of porcelains fused to cast metals. J Prosthet Dent 1960;10(6):1055–1064. DOI: 10.1016/0022-3913(60)90215-8.
Shah R, Singh JP, Kumar M, et al. Dimensional accuracy of castings fabricated with ringless and metal ring investment systems for implant supported fixed dental prosthesis: an in vitro comparative study. Med J Armed Forces India 2011;67(1):46–51. DOI: 10.1016/S0377-1237(11)80012-2.
Konstantoulakis E, Nakajima H, Woody RD, et al. Marginal fit and surface roughness of crowns made with an accelerated casting technique. J Prosthet Dent 1998;80(3):337–345. DOI: 10.1016/S0022-3913(98)70135-0.
Gill PS, Datta K. Analysis of the marginal gap of complete crowns made by using wet and dry ceramic ring liners—an in vitro study. J Indian Prosthodont Soc 2005;5(3):152–154. DOI: 10.4103/0972-4052.18003.
Anusavice KJ. Phillip's Science of dental materials. 11th ed., Philadelphia: W.B. Saunders; 2003. pp. 283–350.
Shillingburg HT, Hobo S, Whittsett LD, et al. Fundamentals of fixed prosthodontics. 3rd ed., Chicago: Quintessence publication; 1997. pp. 365–383.
Craig RG, Powers JM. Restorative Dental Materials. 11th ed., St Louis: Mosby; 2002. pp. 424–448.
Rosenstiel SF, Land MF, Fujimoto J. Contemporary Fixed Prosthodontics. 3rd ed., St Louis: Mosby; 2002. pp. 457–487.
Reddy S, Revathi K, Reddy K. Comparison of marginal accuracy of castings fabricated by conventional casting technique and accelerated casting technique: an in vitro study. Indian Journal of Dental Research 2013;24(4):446–450. DOI: 10.4103/0970-9290.118390.
Lombardas P, Carbunaru A, McAlarney ME, et al. Dimensional accuracy of castings produced with ringless and metal ring investment systems. J Prosthet Dent 2000;84(1):27–31. DOI: 10.1067/mpr.2000.107783.
Hutton JE, Marshall GW. The expansion of phosphate-bonded investment: part I—setting expansion. J Prosthet Dent 1993;70: 121–125. DOI: 10.1016/0022-3913(93)90005-9.
Michio Ito, Kuroiwa A, Nagasaws S, et al. Effect of wax melting range and investment liquid concentration on the accuracy of a three-quarter crown castings. J Prosthet Dent 2002;87:57–61. DOI: 10.1067/mpr.2002.121408.
Jorgensen KD, Okamoto A. Restraining factors affecting setting expansion of phosphate-bonded investments. Scand Dent Res 1986;94(2):178–184. DOI: 10.1111/j.1600-0722.1986. tb01367.x.
Campagni WV, Majchrowicz M. An accelerated technique for casting post and core restorations. J Prosthet Dent 1991;66(2):155–156. DOI: 10.1016/S0022-3913(05)80040-X.
Takahashi J, Olazak M, Taira M, et al. Nonuniform vertical and horizontal setting expansion of a phosphate-bonded investment. J Prosthet Dent 1999;81(1):386–391. DOI: 10.1016/S0022-3913(99) 80003-1.
Del Castillo R, Ercoli C, Graser GN, et al. Effect of ring liner and casting ring temperature on the dimension of cast posts. J Prosthet Dent 2000;84(1):32–37. DOI: 10.1067/mpr.2000.107913.
Parithimarkalaignan S, Hegde V. Evaluation of marginal gap of Ni–Cr based base metal alloys invested in phosphate-bonded investment with the use of conventional and accelerated casting techniques-an in vitro study. Indian J Dent 2011;2(3):76–80. DOI: 10.1016/S0975-962X(11)60019-1.
