The purpose of the study was to determine the exposure times needed to harden a light-activated composite cement through various thicknesses of porcelain. A negative exponential model was developed with which the relative hardness of a composite could be predicted from the product of the exposure time and the square root of the light intensity at 470 nm. Hardness data obtained by varying the exposure time and porcelain thickness were found to fit this model. A relationship was derived to predict the required exposure time, t, of a composite under porcelain with a transmission coefficient, Tc, and a thickness, 1 : t = toT c-½, where to is the exposure time of the composite alone.
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References
1.
Asmussen, E. (1982): Restorative Resins: Hardness and Strength vs. Quantity of Remaining Double Bonds, Scand J Dent Res90 :484-489.
2.
Brodbelt, R.H.W.; O'Brien, W.J.; and Fan, P.L. (1980): Translucency of Dental Porcelains, J Dent Res59:70-75.
3.
Calamia, J.R. (1985): Etched Porcelain Veneers: the Current State of the Art, Quint Int16:5-12.
4.
Calamia, J.R. and Simonsen, R.J. (1984): Effect of Coupling Agents on Bond Strength of Etched Porcelain, J Dent Res63:179, Abst. No. 79.
5.
Cook, W.D. (1980): Factors Affecting the Depth of Cure of UVpolymerized Composites, J Dent Res59:800-808.
6.
Cook, W.D. (1982a): Depth of Cure in the UV Photopolymerization of Dimethacrylate-based Dental Filling Materials, J Macromol Sci-ChemA17(1):99-111.
Cook, W.D. and Standish, P.M. (1983): Cure of Resin Based Restorative Materials. II. White Light Photopolymerized Resins, Aust Dent J28:307-311.
9.
Council On Dental Materials, Instruments, And Equipment (1985): Visible Light-cured Composites and Activating Units, J Am Dent Assoc110:100-103.
10.
De Lange, C.; Bausch, J.R.; and Davidson, C.L. (1980): The Curing Pattern of Photo-initiated Dental Composites , J Oral Rehabil7:369-377.
11.
Fan, P.L.; Wozniak, W.T.; Reyes, W.D.; and Stanford, J.W. (1987): Irradiance of Visible Light-curing Units and Voltage Variation Effects, J Am Dent Assoc115:442-445.
12.
Ferracane, J.L. (1985): Correlation between Hardness and Degree of Conversion during the Setting Reaction of Unfilled Dental Restorative Resins, Dent Mater1:11-14.
13.
Horn, H.R. (1983a): A New Lamination: Porcelain Bonded to Enamel , NY State Dent J49:401-403.
14.
Horn, H.R. (1983b): Porcelain Laminate Veneers Bonded to Etched Enamel , Dent Clin N Amer27:671-684.
15.
Johnston, W.M.; Leung, R.L.; and Fan, P.L. (1985): A Mathematical Model for Post-irradiation Hardening of Photoactivated Composite Resins, Dent Mater1:191-194.
16.
Kilian, R.J. (1979): Visible Light Cured Composite: Dependence of Cure on Light Intensity, IADR Prog & Abst58:No. 603.
17.
Leung, R.L.; Fan, P.L.; and Johnston, W.M. (1983): Post-irradiation Polymerization of Visible Light-activated Composite Resin, J Dent Res62:363-365.
18.
Nathanson, D. and Hassan, F. (1987): Effect of Etched Porcelain Thickness on Resin-Porcelain Bond Strength, J Dent Res66:245, Abst. No. 1107.
19.
Onose, H.; Sano, H.; Kanto, H.; Ando, S.; and Hasuike, T. (1985): Selected Curing Characteristics of Light-activated Composite Resins, Dent Mater1:48-54.
20.
Oster, G. and Yang, N.-L. (1968): Photopolymerization of Vinyl Monomers, Chem Rev68:125-151.
21.
Ray, A.A. (1982): The NLIN Procedure. In: SAS User's Guide: Statistics, Cary, N.C.: SAS Institute, Inc., pp. 15-37.
22.
Ruyter, I.E. and Oysaed, H. (1982): Conversion in Different Depths of Ultraviolet and Visible Light Activated Composite Materials, Acta Odontol Scand40:179-192.
23.
Schulein, T.M.; Boyer, D.B.; and Chalkley, Y. (1984): Bond Strength and Hardness of Light-activated Composite Resins, J Biomed Mater Res18:789-796.
24.
Simonsen, R.J. and Calamia, J.R. (1983): Tensile Bond Strength of Etched Porcelain, J Dent Res62:297, Abst. No. 1154.
25.
Watts, D.C.; Amer, O.; and Combe, E.C. (1984): Characteristics of Visible-light-activated Composite Systems, Br Dent J156:209-215.
