Evaluation of a New Temporary Lining Material

Objectives: Temporary resilient lining materials (tissue conditioners) containing methacrylate polymer and plasticizer are widely used for improvement of the health of a soft tissue in the denture-bearing areas. However, softness of this material is well-known to be lost within the few days due to the elution of the low-molecular-weight plasticizer into the mouth. A new temporary lining material (TissueCare, TC) containing liquid high-molecular polyacrylate as a non-bleeding plasticizer was developed. The purpose was to evaluate the softness and its durability of TC compared with that of commercial temporary lining materials.

Methods: Shore A hardness of TC as well as the commercial temporary resilient lining materials (Lynal, LY; COE-COMFORT, CC; Softone, ST; Visco-gel, VG) was measured. Specimens (9-mm diameter x 12 mm) were immersed in water at 37 C for 4 weeks and measured for Shore A hardness (ISO 7619-1) once per week.

Results: Means (sd, n=3) of Shore A hardness are summarized below. There was only slight variation of hardness in TC compared with other tissue conditioners.

Products	Hardness (Shore A)
	24 hours	2 weeks	4 weeks
TC	11(0.6)	13(0.6)	13(0.6)
LY	22(0.6)	28(1.0)	34(0.6)
CC	6(0)	30(0.6)	38(0.6)
ST	7(0.6)	29(0.6)	31(1.0)
VG	8(0.6)	22(1.2)	28(0.6)

The results showed TC maintained softness for a longer period than other commercial tissue conditioners. It can be assumed that polymeric plasticizer chain was entangled and caught in a methacrylic matrix, which caused reduced leaching.

Conclusions: TC maintained low Shore A hardness during storage in water over a period of 4 weeks compared with other tissue conditioners.