Effects of repeated firing on microleakage of selective laser melting ceramic crowns

Abstract

Abstract: PURPOSE: To investigate the effects of repeated firing on microleakage of selective laser melting ceramic crowns. METHODS: Fifty molars were randomly divided into 2 groups (25 teeth in each group). Teeth in group A received a chamfer finish line preparation, whereas teeth in group B received a shoulder finish line. After SLM metal crowns were fabricated, all the crowns received initial oxidation step, opaque firing, dentin firing and glaze firing, then crowns in each group were randomly divided into 5 sub-groups according to different time of clinical firings. Glass ionomer was applied for bonding. After 5000 thermocycles ranging from 5℃ to 55℃, all the specimens was evaluated by dye penetration and then microleakage was examined under light microscopy. The data were analyzed with SPSS 20.0 software package. RESULTS: Microleakage between all specimens of group A were not statistically significant (P>0.05) whereas that of group B were statistically significant (P<0.05); After the fifth time of clinical firing, microleakage of specimens in group B(B5) were significantly higher than that of group A(A5). CONCLUSIONS: Repeated firings had no significant influence on marginal microleakage of SLM ceramic crowns whereas the crowns of chamfer finish lines result in better clinical performance after repeated firings.

Key words: Selective laser melting, Co -Cr alloy, Microleakage, Repeated firing

CLC Number:

R783.1

ZHONG Qun, PENG Yan, WU Xue-ying, WENG Jia-wei. Effects of repeated firing on microleakage of selective laser melting ceramic crowns[J]. Shanghai Journal of Stomatology, 2016, 25(6): 663-667.

References

[1] Al Jabbari YS, Koutsoukis T, Barmpagadaki X, et al. Metallurgical and interfacial characterization of PFM Co-Cr dental alloys fabricated via casting, milling or selective laser melting [J]. Dent Mater, 2014, 30(4) e79-88.
[2] van Noort R. The future of dental devices is digital [J]. Dent Mater, 2012, 28(1): 3-12.
[3] Xiang N, Xin XZ, Chen J, et al. Metalceramic bond strength of Co-Cr alloy fabricated by selective laser melting[J]. J Dent, 2012, 40(6): 453-457.
[4] Xu D, Xiang N, Wei B. The marginal fit of selective laser melting- fabricated metal crowns: an in vitro study [J]. J Prosthet Dent, 2014, 112(6): 1437-1440.
[5] 陈思宇, 余佳, 陈青娅, 等. 烤瓷烧结对金瓷固定桥边缘适合性的影响 [J]. 四川大学学报(医学版), 2010, 41(3): 536-537.
[6] Vojdani M, Safari A, Mohaghegh M, et al. The effect of porcelain firing and type of finish line on the marginal fit of zirconia copings [J]. J Dent(Shiraz), 2015, 16(2): 113-120.
[7] Sundar MK, Chikmagalur SB, Pasha F. Marginal fit and microleakage of cast and metal laser sintered copings-an in vitro study [J]. J Prosthodont Res, 2014, 58(4): 252-258.
[8] Wu AY, Donovan TE. A modified one-step putty-wash impression technique [J]. J Prosthet Dent, 2007, 98(3): 245-246.
[9] Tay FR, Pashley DH, Hiraishi N, et al. Tubular occlusion prevents water-treeing and through-and-through fluid movement in a single-bottle, one-step self-etch adhesive model [J]. J Dent Res, 2005, 84(10): 891-896.
[10] Tjan AH, Dunn JR, Grant BE. Marginal leakage of cast gold crowns luted with an adhesive resin cement [J]. J Prosthet Dent, 1992, 67(1): 11-15.
[11] Schmid-Schwap M, Graf A, Preinerstorfer A, et al. Microleakage after thermocycling of cemented crowns-a meta-analysis [J]. Dent Mater, 2011, 27(9): 855-869.
[12] Contrepois M, Soenen A, Bartala M, et al. Marginal adaptation of ceramic crowns: a systematic review [J]. J Prosthet Dent, 2013, 110(6): 447-454.
[13] Blatz MB, Sadan A, Martin J, et al. In vitro evaluation of shear bond strengths of resin to densely-sintered high purity zirconium-oxide ceramic after long-term storage and thermal cycling [J]. J Prosthet Dent, 2004, 91(4): 356-362.
[14] Zeng L, Zhang Y, Liu Z, et al. Effects of repeated firing on the marginal accuracy of Co-Cr copings fabricated by selective laser melting [J]. J Prosthet Dent, 2015, 113(2): 135-139.
[15] Fonseca JC, Henriques GE, Sobrinho LC, et al. Stress-relieving and porcelain firing cycle influence on marginal fit of commercially pure titanium and titanium-aluminum-vanadium copings [J]. Dent Mater, 2003, 19(7): 686-691.
[16] Papazoglou E, Brantley WA, Johnston WM. Evaluation of high-temperature distortion of high-palladium metal-ceramic crowns [J]. J Prosthet Dent, 2001, 85(2): 133-140.
[17] Gemalmaz D, Alkumru HN. Marginal fit changes during porcelain firing cycles [J]. J Prosthet Dent, 1995, 73(1): 49-54.
[18] 田孝梅, 曾丽, 魏斌, 等. 激光熔积钴铬合金的热膨胀系数测定 [J].上海口腔医学, 2015, 24(6): 687-689.
[19] Rifat G, Ender K, Yasemin O. Flexural properties of leucite and lithium disilicate ceramic materials after repeated firings [J]. J Dent Sc, 2014, 9(2): 144-150.
[20] Pera P, Gilodi S, Bassi F, et al. In vitro marginal adaptation of alumina porcelain ceramic crowns[J]. J Prosthet Dent, 1994, 72(6): 585-590.