Influence of porcelain firing cycles on marginal adaptation of NiCrTi copings depending on the preparation biomechanics
Influência do ciclo de sinterização da porcelana na adaptação marginal de infraestruturas de NiCrTi em função da biomecânica do preparo
Almeida, Juliana Gomes dos Santos Paes de; Guedes, Carlos Gramani; Fonseca, Renata Garcia; Abi-Rached, Filipe de Oliveira
Rev. odontol. UNESP, vol.39, n4, p.219-225, 2010
Abstract
A metal coping may undergo changes during porcelain firing, which compromises its marginal adaptation. The use of NiCrTi alloy proposes to minimize this effect through the high melting point of titanium present in its composition. This study evaluated the influence of porcelain firing cycle on the marginal adaptation of NiCrTi copings in different preparation designs. Forty standardized metal dies were fabricated with the following combinations finish line/convergence of the axial walls: 1) shoulder/6°; 2) shoulder/20°; 3) sloping shoulder/6°; 4) sloping shoulder/20°. On each die a metal ceramic restoration coping was made. The die/coping set was stabilized with orthodontic elastics, divided into four equidistant areas with three measurement points each and a cementation pressure was simulated. The measurements were taken under a stereomicroscope (32×). After the first measurement, the copings were submitted to sintering cycles simulating porcelain application. For repeated measurements, the same procedures described above were performed. Data were submitted to Student’s-t test, 1-way ANOVA and Tukey´s test (α = 0.05). Adaptation means (µm) before and after porcelain firing in different preparations were: 1) 111.92 and 127.31; 2) 124.15 and 135.48; 3) 122.19 and 138.77; 4) 166.09 and 186.72; respectively. The porcelain firing impaired adaptation, regardless of the preparation design. The preparation in a 20° sloping shoulder provided a worse adaptation when compared with preparations that had 6° and 20° shoulder, which were statistically equal. The 6° sloping shoulder was statistically equal to the other three preparation designs.
Keywords
Marginal adaptation, metal ceramic alloys, tooth preparation
Resumo
A infraestrutura metálica pode sofrer alterações durante a cocção da porcelana que comprometem sua adaptação marginal. A liga de NiCrTi propõe minimizar esse efeito por meio do alto ponto de fusão do titânio presente em sua composição. Este estudo avaliou a influência da temperatura de cocção da porcelana na adaptação marginal de infraestruturas de NiCrTi em diferentes formas de preparo. Foram confeccionados quarenta troquéis metálicos, com as seguintes combinações término cervical/expulsividade das paredes axiais: 1) ombro/6°; 2) ombro/20°; 3) plano inclinado/6°; 4) plano inclinado/20°. Sobre cada troquel, foi confeccionada uma infraestrutura para metalocerâmica. O conjunto troquel/infraestrutura foi estabilizado com elásticos ortodônticos, dividido em quatro faces equidistantes com três pontos de leitura cada e uma pressão de cimentação foi simulada. As leituras foram realizadas em estereomicroscópio (32×). Após a primeira leitura, as infraestruturas foram submetidas aos ciclos de aquecimento para sinterização da porcelana. Para a repetição das leituras, as mesmas condições descritas anteriormente foram realizadas. Os dados foram submetidos ao teste t-Student, ANOVA-1 fator e teste de Tukey (p < 0,05). As médias da fenda marginal (µm) antes e após a cocção da porcelana nos diferentes preparos foram, respectivamente: 1) 111,92 e 127,31; 2) 124,15 e 135,48; 3) 122,19 e 138,77; 4) 166,09 e 186,72. A cocção da porcelana prejudicou a adaptação, independentemente da forma do preparo. O preparo em plano inclinado 20° promoveu uma pior adaptação quando comparado aos preparos em ombro 6° e 20°, que foram estatisticamente iguais entre si. O preparo em plano inclinado 6° foi estatisticamente igual às outras três formas de preparo.
Palavras-chave
Adaptação marginal, ligas metalocerâmicas, preparo dental
References
1. Prado RA, Parenzi H, Fernandes Neto AJ, Neves FD, Silva MR, Mendonça G. Shear bond strength of dental porcelains to nickel-chromium alloys. Braz Dent J. 2005; 16: 202-6.
2. Fernandes Neto AJ, Parenzi H, Neves FD, Prado RA, Mendonça G. Bond strength of three dental porcelains to Ni-Cr and Co-Cr-Ti alloys. Braz Dent J. 2006; 17: 24-8.
3. Bezzon OL, Ribeiro RF, Rollo JMDA, Crosara S. Castability and resistance of ceramometal bonding in Ni-Cr and Ni-Cr-Be alloys. J Prosthet Dent. 2001; 85: 299-304.
4. Komine F, Shiratsuchi H, Kakehashi Y, Matsumura H. Influence of porcelain-firing procedures on the marginal distortion of electroformed metal-ceramic restorations. Quintessence Int. 2007; 38: E583-8.
5. Johnson T, van Noort R, Stokes CW. Surface analysis of porcelain fused to metal systems. Dent Mater. 2006; 22: 330-7.
6. Gemalmaz D, Alkumru HN. Marginal fit changes during porcelain firing cycles. J Prosthet Dent. 1995; 73: 49-54.
7. Wanserski DJ, Sobczak KP, Monaco JG, McGivney GP. An analysis of margin adaptation of all-porcelain facial margin ceramometal crowns. J Prosthet Dent. 1986; 56: 289-92.
8. Felton DA, Kanoy BE, Bayne SC, Wirthman GP. Effect of in vivo crown margin discrepancies on periodontal health. J Prosthet Dent. 1991; 65: 357-64.
9. Chan DCN, Wilson Jr AH, Barbe P, Cronin Jr RJ, Chung C, Chung K. Effect of preparation convergence on retention and seating discrepancy of complete veneer crowns. J Oral Rehabil. 2004; 31: 1007-13.
10. Gavelis JR, Morency JD, Riley ED, Sozio RB. The effect of various finish line preparations on the marginal seal and occlusal seat of full crown preparations. J Prosthet Dent.1981; 45: 138-45.
11. Hunter AJ, Hunter AR. Gingival margins for crowns: a review and discussion. Part II: Discrepancies and configurations. J Prosthet Dent. 1990; 64: 636-42.
12. Matuda FS, Figueiredo AR, Castro Filho AA, Macedo NL. Influência da expulsividade das paredes axiais na adaptação de coroas totais metálicas ante diferentes términos cervicais. Rev Odontol UNESP. 2000; 29: 195-204.
13. Shiratsuchi H, Komine F, Kakehashi Y, Matsumura H. Influence of finish line design on marginal adaptation on electroformed metal‑ceramic crowns. J Prosthet Dent. 2006; 95: 237-42.
14. Buchanan WT, Svare CW, Turner KA. The effect of repeated firings and strength on marginal distortion in two ceramometal systems. J Prosthet Dent. 1981; 45: 502-6.
15. Huang HH. Effect of chemical composition on the corrosion behavior of Ni-Cr-Mo dental casting alloys. J Biomed Mater Res. 2002; 60: 458-65.
16. Inoue RT, Zanetti AL, Feltrin PP, Farias FAR. Nova técnica de referência para preparos dentais denominada Inoue & Zanetti. Rev Assoc Paul Cir Dent. 2001; 55: 431-6.
17. Goodacre CJ, Campagni WV, Aquilino SA. Tooth preparations for complete crowns: an art form based on scientific principles. J Prosthet Dent. 2001; 85: 363-76.
18. McLean JW, von Fraunhofer JA. The estimation of cement film thickness by an in vivo technique. Br Dent J. 1971; 131: 107-11.
19. Rosner D. Function, placement, and reproduction of bevels for gold castings. J Prosthet Dent. 1963; 13: 1160-6.
20. Sozio RB. The marginal aspect of the ceramo-metal restoration: the collarless ceramo-metal restoration. Dent Clin North Am.1977; 21: 787-801.
21. Campbell SD, Sirakian A, Pelletier LB, Giordano RA. Effects of firing cycle and surface finishing on distortion of metal ceramic castings. J Prosthet Dent. 1995; 74: 476-81.
22. Campbell SD, Pelletier LB. Thermal cycling distortion of metal ceramics: part I – metal collar width. J Prosthet Dent. 1992; 67: 603-8.
23. Chew CL, Norman RD, Stewart GP. Mechanical properties of metal-ceramic alloys at high temperature. Dent Mater. 1990; 6: 223-7.
24. Anusavice KJ, Gray AE. Influence of framework design, contraction mismatch, and thermal history on porcelain checking in fixed partial dentures. Dent Mater. 1989; 5: 58-63.
25. Anusavice KJ, Carroll JE. Effect of incompatibility stress on the fit of metal-ceramic crowns. J Dent Res. 1987; 66: 1341-5.
26. Singla A, Shetty P, Joseph M, Kotian R. Comparative evaluation of the effect of simulated porcelain firing cycle on the mechanical properties and microstructure of base metal ceramic alloys. Indian J Dent Res. 1999; 10: 122-9.
27. Fonseca JC, Henriques GE, Sobrinho LC, Góes MF. Stress-relieving and porcelain firing cycle influence on marginal fit of commercially pure titanium and titanium-aluminum-vanadium copings. Dent Mater. 2003; 19: 686-91.
28. Warpeha WS, Goodkind RJ. Design and technique variables affecting fracture resistance of metal-ceramic restorations. J Prosthet Dent. 1976; 35: 291-8.
29. DeHoff PH, Anusavice KJ. Effect of metal design on marginal distortion of metal-ceramic crowns. J Dent Res. 1984; 63: 1327-31.
30. Shillingburg HT, Hobo S, Fisher DW. Preparation design and margin distortion in porcelain-fused-to-metal restorations. J Prosthet Dent. 1973; 29: 276-84.
31. Hobo S, Shillingburg HT. Porcelain fused to metal: tooth preparation and coping design. J Prosthet Dent. 1973; 30: 28-36.
32. Faucher RR, Nicholls JI. Distortion related to margin design in porcelain-fused-to-metal restorations. J Prosthet Dent. 1980; 43: 149-55.
33. Richter-Snapp K, Aquilino SA, Svare CW, Turner KA. Change in marginal fit as related to margin design, alloy type, and porcelain proximity inporcelain-fused-to-metal restorations. J Prosthet Dent. 1988; 60: 435-9.
34. Christensen GJ. Marginal fit of gold inlay castings. J Prosthet Dent. 1966; 16: 297-305.
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