Influence of Water Exposure on the Tensile Strength of Composites

Abstract

The objective of this study was to investigate whether water storage causes permanent damage to composites by determining how the tensile strength of nine different composite materials changes with both water storage and water storage followed by dehydration. Eighteen samples (ASTM-D Specification 1708-66) of each of the nine materials were prepared and divided into three groups of six samples each. Group I was stored dry at 60°C, while Groups II and III were stored in distilled water at 60°C. After six months, Groups I and II were subjected to tensile testing, while Group III was transferred to a desiccator and dehydrated for two weeks at 60°C before this group was tested in tension. Mean values, pooled by storage group independent of material, revealed a significant (p<0.05) reduction in strength for both Groups II and III relative to Group I. These findings prove that water has an irreversible effect on most dental composites. A comparison of Group II with Group III data revealed that the samples which were aged in water and tested (Group II) were significantly (p<0.05) weaker than the dehydrated samples (Group III). However, some products within Group III did not show any tendency to recover their strength after dehydration.

Get full access to this article

View all access options for this article.

References

Calais, J.G. and Soderholm, K.-J.M. (1988): Influence of Filler Type and Water Exposure on Flexural Strength of Experimental Composite Resins, J Dent Res 67:836-840.

Davidson, C.L. (1987): Posterior Composites: Criteria for Assessment . Discussion and Conclusions, Quint Int 18:47-48.

Draughn, R.A. (1985): Fatigue and Fracture Mechanics of Composite Resins . In: Posterior Composite Resin Dental Restorative Materials , G. Vanherle and D.C. Smith , Eds., Utrecht: Peter Szulc Publishing Co., pp. 299-307.

Farah, J.W. ; Clark, A.E. ; Mohsein, M. ; and Thomas, P.A. (1983): Effect of Cement Base Thicknesses on MOD Amalgam Restorations, J Dent Res 62:109-111.

Lambrechts, P. ; Ameye, C. ; and Vanherle, G. (1982): Conventional and Microfilled Composite Resins. Part II. Chip Fractures, J Prosthet Dent 48:527-538.

Leinfelder, K.F. (1985): Evaluation of Clinical Wear of Posterior Composite Resins. In: Posterior Composite Resin Dental Restorative Materials , G. Vanherle and D.C. Smith , Eds., Utrecht: Peter Szulc Publishing Co., pp. 501-509.

Leinfelder, K.F. (1989): Criteria for Clinical Evaluation of Composite Resin Restorations. In: Quality Evaluation of Dental Restorations. Criteria for Placement and Replacement, K.J. Anusavice , Ed., Chicago: Quintessence Publishing Co., pp. 139-146.

McComb, D. (1985): Discussion Paper: Evaluation of Clinical Wear of Posterior Composite Resins. In: Posterior Composite Resin Dental Restorative Materials, G. Vanherle and D.C. Smith , Eds., Utrecht: Peter Szulc Publishing Co., pp. 511-517.

McKinney, J.E. (1985): Environmental Damage and Wear of Dental Composite Restoratives. In: Posterior Composite Resin Dental Restorative Materials, G. Vanherle and D.C. Smith , Eds., Utrecht: Peter Szulc Publishing Co., pp. 331-347.

10.

Mjor, I.A. (1981): Placement and Replacement of Restorations, Oper Dent 6:49-54.

11.

Moffa, J.P. ; Jenkins, W.A. ; and Hamilton, J.C. (1984): The Longevity of Composite Resins for the Restoration of Posterior Teeth, J Dent Res 63:199, Abstr. No. 253.

12.

Phillips, R.W. ; Avery, D.R. ; Mehra, R. ; Swartz, M.L. ; and McCune, R.J. (1973): Observations on a Composite Resin for Class II Restorations: Three-Year Report, J Prosthet Dent 30:891-897.

13.

Prasad, S.V. and Calvert, P.D. (1980): Abrasive Wear of Particle Filled Polymers, J Mater Sci 15:1746-1754.

14.

Sas Institute, Inc. (1985): The GLM Procedure. In: SAS User's Guide: Statistics, Version 5Edition, Cary, NC: SAS Institute, Inc., pp. 433-506.

15.

Soderholm, K.-J.M. (1983): Leaking of Fillers in Dental Composites, J Dent Res 62:126-130.

16.

Soderholm, K.-J. M. (1984): Influence of Silane Treatment and Filler Fraction on Thermal Expansion of Composite Resin, J Dent Res 63:1321-1326.

17.

Soderholm, K.-J.M. (1985): Filler Systems and Resin Interface. In: Posterior Composite Resin Dental Restorative Materials, G. Vanherle and D.C. Smith , Eds., Utrecht: Peter Szulc Publishing Co., pp. 139-159.

18.

Soderholm, K.-J.M. (1990): Filler Leachability During Water Storage of Six Composite Materials, Scand J Dent Res 98:82-88.

19.

Soderholm, K.-J.M. and Calvert, P.D. (1983): Effects of Water on Glass-filled Methacrylate Resins, J Mater Sci 18 :2957-2962.

20.

Soderholm, K.-J. M.; Zigan, M. ; Ragan, M. ; Fischl-Schweiger, W. ; and Bergman, M. (1984): Hydrolytic Degradation of Dental Composites, J Dent Res 63:1248-1254.

21.

Vanherle, G. and Smith, D.C. (1985): Posterior Composite Resin Dental Restorative Materials , Utrecht: Peter Szulc Publishing Co.

22.

Zidan, O. ; Asmussen, E. ; and J0RGENSEN, K.D. (1980): Tensile Strength of Restorative Resins, Scand J Dent Res 88:285-289.