PMID- 28580464 OWN - Quintessenz Verlags-GmbH CI - Copyright Quintessenz Verlags-GmbH OCI - Copyright Quintessenz Verlags-GmbH TA - J Adhes Dent JT - The Journal of Adhesive Dentistry IS - 1757-9988 (Electronic) IP - 3 VI - 19 PST - ppublish DP - 2017 PG - 213-220 LA - en TI - Addition of Na2CO3 Improves the Shelf Life of Experimental 4-META Self-etch Primer LID - 10.3290/j.jad.a38412 [doi] FAU - Matsumoto, Hiro AU - Matsumoto H FAU - Yamamoto, Takatsugu AU - Yamamoto T FAU - Hanabusa, Masao AU - Hanabusa M FAU - Momoi, Yasuko AU - Momoi Y FAU - Hayakawa, Tohru AU - Hayakawa T CN - OT - 4-META OT - self-etch primer OT - pH OT - shelf time OT - bond strength OT - hydrolytic stability AB - Purpose: The objective of this study was to assess the influence of the addition of Na2CO3 on the shelf life and bond strength of 4-META self-etch primer. Materials and Methods: Two 4-META self-etch primers were experimentally formulated with and without the addition of Na2CO3 (primer A and primer B, respectively). The primers were stored at 37°C for several periods of time after formulation. Clearfil SE Bond Primer (Kuraray Noritake Dental) was used as a control. A composite was bonded to bovine dentin using a combination of the primer and a bonding agent (Clearfil SE Bond), and the shear bond strengths were measured. Changes in the pH of the experimental primers were monitored and macroscopic observations were made as a function of the storage periods. Results: With 0-day storage, the bond strength of primer A was equivalent to that of primer B and significantly lower than that of Clearfil SE Primer. The bond strengths of primer A were stable during 90-day storage; by contrast, the bond strengths of primer B significantly decreased during 7-day storage. primer A exhibited stable pH values during 180-day storage; primer B exhibited significantly lower pH than primer A with 0-day storage and discolored gelation during 7-day storage. Conclusion: By adding Na2CO3, the shelf life of the 4-META self-etch primer was obviously improved without significant deterioration in dentin bond strength. Adjusting the pH to around 4.5 was effective for obtaining sufficient bond strength and hydrolytic stability of the primer. AID - 843351