EVALUATION OF SHORE A HARDNESS OF MAXILLOFACIAL SILICONES: THE EFFECT OF DARK STORAGE AND NANOPARTICLES
Purpose: Little has been reported how the addition of nanoparticles could affect the hardness of maxillofacial silicones. The purpose of this study was to evaluate the effects of different types of nanoparticle additives and dark storage for 2-years on the Shore A hardness of two types of maxillofacial silicone elastomers.
Materials and Methods: A-2000 and A-2006 RTV silicone elastomers were tested in this study. Silaned silica, fumed silica and titanium dioxide nanoparticles at concentrations of 10 % by volume were used as fillers for the maxillofacial silicone elastomers. A total of 64 silicone specimens were fabricated, which includes 8 samples, 30x10 mm in size, from each silicone elastomers for each subgroup and also controls. After the initial Shore A hardness measurements, specimens were kept in dark conditions at room temperature for 2 years. The final measurements were then taken from the silicone specimens. All data were statistically analyzed.
Results: For both types of silicones, there was statistically significant differences among study groups (p<0.001). Fumed silica group showed the lowest hardness values in A-2000 after storage. However, no significant difference was observed between control and fumed silica groups. Control group showed the lowest hardness values in A-2006, while the highest hardness values were found in fumed silica group; there was no significant difference between silica and silane groups.
Conclusion: Shore A values of the specimens were within the acceptable range for the maxillofacial silicones after aging. Nanoparticle addition did not prevent hardening of the silicone elastomers with time.
dos Santos DM, Goiato MC, Sinhoreti MA, Moreno A, Dekon SF, Haddad MF, Pesqueira AA. Influence of natural weathering on colour stability of materials used for facial prosthesis. J Med EngTechnol2012;36:267-270.
Cevik P, Eraslan O. Effects of the Addition of Titanium Dioxide and Silaned Silica Nanoparticles on the Mechanical Properties of Maxillofacial Silicones. J Prosthodont2016;[Epub ahead of print] Available from: http://onlinelibrary.wiley.com/doi/10.1111/jopr.12438/abstract
Akash RN, Guttal SS. Effect of incorporation of nano-oxides on color stability of maxillofacial silicone elastomer subjected to outdoor weathering. J Prosthodont 2015;[Epub ahead of print] Available from: http://onlinelibrary.wiley.com/doi/10.1111/jopr.12252/abstract
Akay C, Cevik P, Karakis D, Sevim H. In Vitro Cytotoxicity of Maxillofacial Silicone Elastomers: Effect of Nano-particles. J Prosthodont 2016;[Epub ahead of print] Available from: http://onlinelibrary.wiley.com/doi/10.1111/jopr.12533/abstract
Goiato MC, Pesqueira AA, Ramos da Silva C, Gennari FH, Dos Santos DM. Patient satisfaction with maxillofacial prosthesis. Literature review. J PlastReconstrAesthetSurg2009;62:175-180.
HatamlehMM, Haylock C, Watson J, Watss DC. Maxillofacial prosthetic rehabilitation in the UK: a survey of maxillofacial prosthetists’ and technologists’ attitudes and opinions. Int J Oral MaxillofacSurg2010;39:1186–1192.
Han Y, Kiat-amnuay S, Powers JM, Zhao Y. Effect of nano-oxide concentration on the mechanical properties of a maxillofacial silicone elastomer. J Prosthet Dent 2008;100:465-473.
O’Brein WJ. Dental materials and their selection. In: O’Brein WJ, editor. Physical Properties and Biocompatibility. Michigan: QuintessencePublishing, 2002, p.23.
Polyzois GL, Tarantili PA, Frangou MJ, Andreopoulos AG. Physical properties of a silicone prosthetic elastomer stored in simulated skin secretions. J Prosthet Dent 2000;83:572-577
Dootz, ER, Koran A, Craig RG. Physical properties of three maxillofacial materials as a function of accelerated aging. J Prosthet Dent 1994;71:379-383.
Veres EM, Wolfaardt JF, Becker PJ. An evaluation of the surface characteristics of a facial prosthetic elastomer. Part I: Review of the literature on the surface characteristics of dental materials with maxillofacial prosthetic application. J Prosthet Dent 1990;63:193-197.
Polyzois GL. A study of the effect of crosslinking of hydroxyl terminated polydimethylsiloxane. Doctoral Dissertation, University of Wales, 1987.
Haug SP, Andres CJ, Munoz CA, Okamura M. Effects of environmental factors on maxillofacial elastomers: part III-physical properties. J Prosthet Dent 1992;68:644–651.
Haug SP, Moore BK, Andres CJ. Color stability and colorant effect on maxillofacial elastomers. Part II: weathering effect on physical properties. J Prosthet Dent 1999;81:423–430.
Hatamleh MM, Polyzois GL, Silikas N, Watts DC. Effect of extraoral aging conditions on mechanical properties of maxillofacial silicone elastomer. J Prosthodont 2011;20:439-446.
Wiens JP. A comparative study of selected elastomers subjected to accelerated and outdoor weathering. Doctoral Dissertation, University of Minnesota, 1980.
Polyzois GL, Eleni PN, Krokida MK. Effect of time passage on some physical properties of silicone maxillofacial elastomers. J CraniofacSurg2011;22:1617–1621.
Visser A, Raghoebar G, Van Oort R, Vissink A. Fate of implant-retained craniofacial prostheses: life span and aftercare. Int J Oral Maxillofac Implants 2008;23:89–98.
Hooper SM, Westcott TP, Evans PL, Bocca AP, Jagger DC. Implant-supported facial prostheses provided by a maxillofacial unit in a U.K. regional hospital: longevity and patient opinions. J Prosthodont 2005;14:32–38.
Chen MS, Udagama A, Drane JB. Evaluation of facial prostheses for head and neck cancer patients. J Prosthet Dent 1981;46: 538–544.
Jani RM, Schaaf NG. An evaluation of facial prostheses. J Prosthet Dent 1978;39:546–550.
Jebreil K. Acceptability of orbital prostheses. J Prosthet Dent 1980;43:82–85.
Hulterström AK, Ruyter IE. Changes in appearance of silicone elastomers for maxillofacial prostheses as a result of aging. Int J Prosthodont 1999;12:498-504.
Montgomery PC, Kiat-Amnuay S. Survey of currently used materials for fabrication of extraoral maxillofacial prostheses in North America, Europe, Asia, and Australia. J Prosthodont 2010;19:482–490.
Polyzois G, Lyons K. Monitoring Shore A hardness of silicone facial elastomers: the effect of natural aging and silicone type after 1 year.J CraniofacSurg2014;25:1217-1221.
Conroy B, Haylock C, Hulterstrom AK, Pratt G, Winter RW.Report of a four year research and development programme involving the Institute of Maxillofacial Technology and the University of Wales Institute of Science and Technology aimed at the production of a new facial prosthetic system. Proc Inst MaxillofacTechnol 1979;218–245
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